CN113047766B - Inner and outer ladder locking device and multifunctional ladder comprising same - Google Patents

Abstract

The invention discloses an inner ladder and outer ladder locking device and a multifunctional ladder comprising the same, wherein the locking device comprises a stepping lock assembly, a stepping cavity assembly and an unlocking assembly; the step lock assembly comprises a lock tongue, a connecting base, a connecting rod, a trigger and a lock pin which are arranged on the inner ladder step, wherein the lock tongue is provided with a locking hole, and the trigger is provided with a trigger point and a trigger hole; the pedal cavity assembly is arranged on the pedal of the outer ladder and is provided with a cavity and a trigger part which are correspondingly arranged, the unlocking assembly is a pulling mechanism acting on the lock pin, and the pulling mechanism is connected with the lock pin and is used for pulling the lock pin out of the locking hole and the trigger hole. The scheme not only considers the realization of unlocking and locking functions, can meet the convenience and the smoothness of operation, but also considers the design standard to be met by the multifunctional ladder as a loading structure, and the mechanism is matched to complete finer and reasonable locking and unlocking actions, so that the locking is guaranteed, the locking cannot be rotated and separated, and the safety is improved.

Description

Inner and outer ladder locking device and multifunctional ladder comprising same

Technical Field

The invention relates to the technical field of ladders, in particular to an inner ladder and outer ladder locking device and a multifunctional ladder comprising the same.

Background

The ladder is a common tool for climbing, and a straight ladder or a herringbone ladder is common. In most cases, the ladder can meet the climbing requirement of the user, but in some cases, such as when the user needs to climb to a height exceeding the limit of the ladder, the ladder cannot meet the climbing requirement.

In order to solve the problem, the industry discloses a combined ladder which comprises an inner ladder and an outer ladder, wherein a ladder column of the outer ladder is sleeved on a ladder column of the inner ladder, and the outer ladder can slide up and down on the inner ladder so as to achieve the effect of increasing the overall climbing limit of the ladder. In order to lock the position of the stiles of the outer ladder on the stiles of the inner ladder, locking means are usually provided between the stiles of the inner and outer ladder. The traditional locking device structure is characterized in that the outer sides of two ladder columns of the outer ladder are provided with elastic locking pins, a plurality of locking holes are formed in the ladder columns of the inner ladder along the length direction of the ladder columns, and the elastic locking pins are used for being matched with the locking holes at different height positions to position the outer ladder and the inner ladder. The conventional locking device has the following problems found in long-term use: 1. if, in order to pursue the reliability of locking, the spring of the elastic locking pin is required to have enough tension, so that the unlocking of the locking device is quite inconvenient when the height of the ladder is adjusted; 2. if the convenience of operation of the locking device is sought after for the ladder to be lifted, it is required that the spring of the resilient locking pin not be pulled too much, thus again reducing the reliability of the locking.

The applicant has therefore developed a combination ladder for the above-mentioned drawbacks and filed a chinese patent with publication number "CN105525862B" (patent name "a height-adjustable combination ladder", patent number "CN 201610033751.2), which discloses a height-adjustable combination ladder comprising an inner ladder, an outer ladder and a locking device for locking the inner ladder and the outer ladder, the locking device comprising two parts, a base and a handle; the seat body is fixedly arranged on a ladder column of the outer ladder, and a columnar cavity is formed in the seat body for the rod-shaped lock pin to penetrate; the rod-shaped lock pin reciprocates in the columnar cavity; the handle rotates the outside that sets up in the pedestal, and its inboard is concavely equipped with the rotation cavity, and this rotation cavity cover is established and is rotated on the pedestal. In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art: 1. in order to enable the combined ladder to meet the strength requirement of relevant industry standards when in use, most of locking devices in the prior art are arranged on the left side and the right side of a ladder column respectively, when in unlocking operation of height adjustment, the locking devices on the left side and the right side are required to be unlocked respectively, the locking devices are respectively locked at the adjusted heights, the locking devices on the left side and the right side of the ladder column are required to be kept in the same locking or unlocking state so as to be capable of performing corresponding operation, and the prior structure is complex in operation steps and time and labor are wasted; 2. because the locking device of current combination ladder is located the upper end of outer ladder column more, when carrying out the unblock operation of altitude mixture control, need put the combination ladder and put down the back again, stand up the ladder again after the altitude mixture control is accomplished and use or hang and lean on the use, because the combination ladder is the load of metal and use the goods, the weight of combination ladder can be heavier, in addition if judge the inaccurate combination ladder altitude mixture control of need many times to the altitude mixture control, need constructor put down, erect the combination ladder many times, the operating strength of constructor has been increased, there is some narrow and small construction scene not also has the space to put down the combination ladder, consequently also brought certain limitation.

In view of this, how to solve the problems of complicated steps, time and labor waste, increased operation strength of constructors, inapplicability to special occasions and the like in the prior art of the height adjusting and locking device of the multifunctional ladder becomes the subject to be studied and solved by the invention.

Disclosure of Invention

The invention provides an inner and outer ladder locking device and a multifunctional ladder comprising the same, and aims to solve the problems that the prior multifunctional ladder height adjusting and locking device is complex in steps, time-consuming and labor-consuming, increases the operation strength of constructors, cannot be suitable for special occasions and the like, so that the convenience, safety and applicability of the multifunctional ladder are improved.

In order to achieve the above-mentioned object, according to a first aspect of the present invention, there is provided an inner/outer ladder locking device for unlocking and locking an inner ladder and an outer ladder, wherein the outer ladder is sleeved on the inner ladder posts, a plurality of inner ladder steps transversely arranged along the length direction of the inner ladder posts are arranged between the inner ladder posts, and a plurality of outer ladder steps corresponding to the inner ladder steps are arranged between the outer ladder posts, and the innovation point is that:

The locking device comprises a stepping lock assembly, a stepping cavity assembly and an unlocking assembly; wherein:

The stepping lock assembly comprises a lock tongue, a connecting base, a connecting rod, a trigger and a lock pin;

The connecting base is used as a foundation of the step lock assembly and is connected with the inner ladder step in a positioning way; the connecting rod and the lock tongue are transversely hinged on the connecting base, and the lock tongue rotates around the axis of the connecting rod; the lock tongue is a block-shaped member, the block-shaped member is hinged on the connecting rod, and the connecting rod is positioned on the connecting base, so that the lock tongue can rotate around the connecting rod; the first elastic piece is arranged relative to the connecting base, acts on the lock tongue and forces the lock tongue to stay in the middle position in the rotation range of the lock tongue;

The trigger is a disc-shaped member, and a trigger point and a trigger hole are arranged on the disc-shaped member; the lock tongue is provided with a locking hole corresponding to the trigger hole, and a second elastic piece is arranged opposite to the lock pin, and acts on the lock pin and forces the lock pin to move towards the locking hole when the lock tongue is in a middle position state;

A rotary action part is arranged between the trigger and the lock tongue, the trigger is rotationally connected with the lock tongue around the rotary action part, a third elastic piece is arranged relative to the rotary action part, and the third elastic piece acts on the trigger and forces a trigger hole of the trigger to rotate towards a direction far away from a locking hole of the lock tongue;

the unlocking component is a pulling mechanism acting on the lock pin, the pulling mechanism is connected with the lock pin and is used for pulling the lock pin out of the locking hole and the triggering hole, the trigger rotates relative to the lock pin under the action of the third elastic piece in the state that the lock pin is pulled out of the triggering hole, so that the triggering hole of the trigger deviates from the inserting position of the lock pin, and meanwhile, the side surface of the trigger abuts against the lock pin to prevent the lock pin from being inserted, so that an unlocking state is formed in which the lock tongue can rotate along the connecting rod;

The pedal cavity assembly is arranged on the outer ladder pedal and is provided with a cavity body and a triggering part which are correspondingly arranged; the cavity corresponds to a lock tongue in the stepping lock assembly and is matched with the lock tongue to extend into the cavity for realizing support and limit; the trigger part corresponds to a trigger point in the step lock assembly, when the outer step reaches a locking position relative to the inner step, the trigger part is propped against the trigger point and exerts a turning force, the turning force overcomes the elastic force of the third elastic piece to enable the trigger hole of the trigger to be positioned at the lock pin inserting position, and the lock pin is inserted into the locking hole and the trigger hole under the action of the second elastic piece in the state, so that the locking state of the step lock assembly and the step cavity assembly is formed.

In a second aspect, the invention also discloses a multifunctional ladder, which comprises an inner ladder and an outer ladder, and the multifunctional ladder further comprises the inner and outer ladder locking device in the technical scheme of the first aspect.

The content of the present invention is explained as follows:

1. According to the invention, the step lock assembly, the step cavity assembly and the unlocking assembly are arranged between the outer ladder and the inner ladder, so that the realization of unlocking and locking functions is considered, convenience and smoothness of operation can be met, and the design standard to be met by taking the multifunctional ladder as a load structure is considered, and the unlocking and locking structure meets certain strength requirements; the locking device is arranged on the steps of the inner ladder and the outer ladder, the structural characteristics of the original steps of the inner ladder and the outer ladder are skillfully utilized, the step lock component and the unlocking component are integrated into the original structure of the steps of the inner ladder, the step cavity component is integrated into the original structure of the steps of the outer ladder, after the inner ladder and the outer ladder are positioned at the locking positions, the locking states of the step lock component and the step cavity component are matched with the structures of the inner ladder and the outer ladder, a user can normally step, excessive space is not occupied, and the normal use and storage of the multifunctional ladder are not influenced. The unlocking and locking processes in the locking device are specially designed, in the unlocking process, after the locking pin is pulled out by the unlocking component, the trigger enables the trigger Kong Bikai to trigger the locking pin and prop against the locking pin under the action of the third elastic piece, so that the lock tongue is in an unlocking state capable of rotating freely, in this state, the lock tongue is in a centering position under the action of the first elastic piece, the centering position enables the lock tongue and the trigger to be in a state to be excited, and at the moment, the outer ladder can move up and down; when the outer ladder moves to a proper position, the lock tongue gradually enters the cavity, and a trigger point in the trigger is also contacted with a trigger part in the stepping cavity assembly, so that the trigger is pushed to rotate around the rotating action part, the trigger hole returns to the initial position, the lock pin can return to enter the locking hole, and the lock tongue is locked, so that the lock tongue cannot rotate. Therefore, by adopting the technical scheme, the locking device is arranged on the inner ladder and the outer ladder steps which are easy to reach by hands, the using state of the multifunctional ladder is not considered when the unlocking is carried out, constructors can unlock the ladder in the vertical state, the unlocking process is convenient and easy to operate, the fine and reasonable actions are completed by the matching of the simple mechanisms, the locking is ensured, the rotation and detachment can not be carried out after the locking is ensured, and the safety is improved.

2. In the invention, the unlocking component comprises an unlocking rod, an unlocking connecting part and an unlocking force applying part, wherein the unlocking rod is arranged on an inner ladder step, one end of the inner ladder step is provided with an unlocking rotary point, the other end of the unlocking rod is connected with the unlocking connecting part, the unlocking force applying part is connected with the unlocking connecting part, the unlocking connecting part is connected with a lock pin, the unlocking force applying part is driven by external force to rotate around the unlocking rotary point and drive the unlocking connecting part to move, and the unlocking connecting part drives the lock pin to outwards pull out a locking hole. The unlocking connecting part is provided with a locating pin and a connecting sheet, and the unlocking connecting part is connected with the lock pin through the locating pin and the connecting sheet. The unlocking assembly is used for unlocking the lock tongue, the parallel connection trigger is used for ensuring that the lock pin is not returned in the unlocking state, ensuring the smoothness of the outer ladder in the unlocking state when the vertical position of the outer ladder is adjusted, and the unlocking operation is simple.

3. In the invention, the unlocking force applying part is at least one of a handle or a pull rope; wherein:

When the unlocking force application part is a handle, the handle is arranged on the inward side of the inner ladder step and is fixedly connected with the unlocking rod, the length direction of the handle is consistent with the length direction of the unlocking rod, the handle is used as the unlocking force application part, an operator only needs to stand on one side of the multifunctional ladder in an upright or flat state, the handle is lifted by one hand, the step lock assembly can be unlocked, the lock pin can be pulled out after the handle is lifted, and the trigger acts against the lock pin at the moment, so that the lock tongue can be in a free rotation state;

When the unlocking force application part is a pull rope, a pulley mechanism is arranged on the other side of the turning point of the unlocking rod on the inner ladder step, the pulley mechanism comprises a pulley and a pulley bracket, the pulley bracket is fixedly connected with the unlocking rod, the pull rope passes through the pulley and then is connected with the unlocking connection part, a plurality of rope buckles used for passing through the pull rope are arranged on the ladder column of the outer ladder, and the rope buckles are arranged along the length direction of the ladder column; when the pull rope is used as the unlocking force applying part, an operator can stand on one side of the multifunctional ladder to perform height adjustment operation, and can stand on the ladder steps to perform operation in the following operation modes: the operator stands on the step of ladder one side, the staff is to the stay cord example with the lock subassembly of marking time of unblock opposite side, after the lock subassembly unblock of marking time, continue to exert force to the stay cord, make lock subassembly and mark time the chamber subassembly dislocation of marking time get into next locked position, internal ladder and outer ladder change in the position on length direction promptly, make internal ladder mark time counterpoint with next outer ladder mark time, loosen the stay cord this moment, by the chamber subassembly of marking time on the outer ladder mark time to the trigger in the lock subassembly of marking time of internal ladder exert force, with the spring bolt locking is motionless, thereby accomplish the regulation of internal ladder and outer ladder one-step height position. The operator can finish the height adjustment of the multifunctional ladder without descending the ladder in the mode, the operation of the operator is utilized more, the climbing and descending are not needed, the multifunctional ladder is also beneficial to being suitable for various different occasions, and various requirements are met.

4. In the invention, the unlocking assembly further comprises an unlocking reset part, the unlocking reset part comprises a fourth elastic piece, the fourth elastic piece is a reset spring, one end of the reset spring is fixed with the unlocking connecting part, the other end of the reset spring is connected with the connecting base or the inner ladder step, a movement trend of resetting the unlocking connecting part relative to the initial position is formed, the increased unlocking reset part can be prepared for the next unlocking of the unlocking assembly, the unlocking connecting part can be reset in the locking process after unlocking, and the unlocking reset part and the second elastic piece can be linked to jointly complete resetting of the locking pin and the unlocking connecting part.

5. In the invention, a locking hole is formed in the lock tongue, and the locking hole is used for the lock pin to pass through; the bolt is provided with a rotary mounting hole on the same side of the locking hole, and the rotary action part is arranged in the rotary mounting hole; the hinge hole is formed in the lock tongue, the connecting rod penetrates through the hinge hole, the rotary mounting hole and the locking hole are arranged on the outer side of the circumference of the hinge hole, so that space is provided for rotation of the lock tongue and rotation of the trigger, the locking hole on the lock tongue and the triggering hole on the trigger form a dislocation with reasonable positions, the triggering point of the trigger and the triggering part of the stepping cavity assembly are tangent and reset and rotate around the rotary action part, and the reset and rotation distance and path are more reasonable.

6. In the invention, the first elastic piece consists of two groups of torsion springs, a torsion spring seat is fixedly arranged at the middle part of the connecting rod, the first elastic piece is arranged on the connecting rod in a penetrating way and is positioned in the torsion spring seat, one end of the first elastic piece is propped against the torsion spring seat, the other end of the first elastic piece is propped against the lock tongue, the acting force directions of the two groups of torsion springs in the first elastic piece are opposite, and the movement trend that the lock tongue is reset and centered around the axis of the connecting rod is formed. The action part of the first elastic component is formed by the two groups of torsion springs, the acting forces of the two groups of torsion springs are opposite, so that the lock tongue is always centered, the structure of the torsion springs is ingenious, the manufacturing cost is low, the assembly is convenient, the production cost and the production difficulty of the locking device can be reduced, the space layout of the stepping lock assembly positioned on the inner ladder stepping is also beneficial, the torsion spring seat and the torsion springs are all sleeved on the transversely arranged connecting rod, and the space utilization is ingenious.

7. In the invention, a lock pin guide seat is arranged on one side of the connecting base, a lock pin is arranged in the lock pin guide seat, a lock pin restoring mechanism is arranged on the lock pin guide seat, the lock pin is provided with a cylinder body, the lock pin restoring mechanism comprises a second elastic piece, a restoring limiting block arranged in the axial direction of the lock pin cylinder body and a restoring limiting surface arranged on the lock pin guide seat, the restoring limiting block faces the outer side of the lock pin, the restoring limiting block is arranged corresponding to the restoring limiting block, the restoring limiting surface faces the inner side of the lock pin, the second elastic piece is sleeved on the circumferential direction of the lock pin, one end of the second elastic piece is propped against the restoring limiting block, the other end of the second elastic piece is propped against the restoring limiting surface, and the lock pin restoring mechanism is adopted to force the lock pin to move towards a locking hole when the lock pin is always in a middle position, so that the lock pin is ensured to be positioned in a middle position just in a cavity, the lock pin can be accurately, quickly and reliably locked after the lock pin reaches the locking position, the lock pin can be unlocked only through an unlocking component when the lock pin is moved, swung or flatly arranged in a ladder in a normal mode, and the locking state is safer and more reliable.

8. In the invention, the trigger point is arranged at one circumferential outward side of the trigger and protrudes outwards, the trigger is also provided with a first notch, the first notch is provided for the connecting rod to pass through, the first notch is arc-shaped, the first notch is used as a limit path for the rotation displacement of the trigger, the notch passes through the center position of the trigger, the rotation path of the trigger is limited by the notch, the trigger can not rotate too much when rotating around the rotating action body under the action of the third elastic piece, and the angle of stressed rotation of the trigger point on the trigger is just suitable when the trigger part is in conflict, so that each structure of the locking device is further more reasonable.

9. In the invention, the trigger is rotatably arranged at the outer side of the lock tongue, the third elastic piece is provided with a first acting end and a second acting end, the first acting end acts on the trigger, and the second acting end acts on the lock tongue, so that the trigger has a movement trend of rotating around a return point relative to the lock tongue under the limiting action of the rotary acting part and the elastic deformation action of the third elastic piece.

10. In the invention, the pedal cavity component comprises a back cover plate and an inner plug, wherein a cavity is arranged in the inner plug, a lock tongue fixing groove for supporting a lock tongue and meeting the load requirement is arranged in the cavity, a lock tongue limiting point for fixing the lock tongue from falling off is arranged on one side of the back cover plate, a trigger part is positioned on the outer surface of the back cover plate, and because the trigger point of a trigger protrudes outwards, the trigger part is the outer surface of the back cover plate, when the outer ladder pedal reaches a locking position, the back cover plate is tangent to the trigger point of the trigger so as to push the trigger to rotate.

12. In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically linked, may be directly linked, may be indirectly linked through an intervening medium, and may be in communication between two elements or in an interactive relationship therebetween, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

13. In the present application, the positional or positional relationship indicated by the terms "upper", "lower", "upward", "downward", etc. are positional or positional fitting relationship based on those shown in the drawings, are merely for convenience of description of the present application and simplification of description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present application.

14. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Due to the application of the scheme, compared with the prior art, the invention has the following advantages and effects:

1. According to the scheme, the locking device is arranged on the steps of the inner ladder and the outer ladder, the structural characteristics of the original steps of the inner ladder and the outer ladder are utilized, the step lock assembly and the unlocking assembly are integrated into the original structure of the steps of the inner ladder, the step cavity assembly is integrated into the original structure of the steps of the outer ladder, after the inner ladder and the outer ladder are positioned at the locking positions, the locking states of the step lock assembly and the step cavity assembly are matched with the structures of the inner ladder and the outer ladder, a user can normally step, excessive space is not occupied, and the normal use and storage of the multifunctional ladder are not influenced;

2. according to the scheme, special designs are carried out on the unlocking and locking processes in the locking device, so that the unlocking action is ensured to be simple and convenient to operate; the unlocking action can be completed by a single person and one hand, so that the up-and-down adjustment of the outer ladder after unlocking is smooth, the lock pin is always positioned at the unlocking position under the linkage action of the third elastic piece of the trigger, and the step lock assembly is prevented from being locked in advance; in the locking process, the lock tongue with the trend of always staying in the middle position enters the cavity of the stepping cavity assembly, and simultaneously the trigger part acts on the trigger point to enable the lock pin to fall into the locking hole of the lock tongue, so that the reliable locking of the locking device is completed, after the locking, the part of the lock tongue, which is forced to enter the cavity, bears part of the lock tongue, and the lock tongue, the lock pin and the connecting base share part of the lock tongue, so that the lock tongue is stable in stress structure and is enough to bear a certain load, and the load requirement in various industry standards can be met;

3. According to the scheme, the locking device is arranged on the inner ladder and the outer ladder steps which are easy to be reached by hands, the using state of the multifunctional ladder is not considered when the unlocking is carried out, constructors can unlock the multifunctional ladder in the vertical state of the ladder, the unlocking process is convenient and easy to operate, fine and reasonable actions are completed through the cooperation of the simple mechanisms, the locking is guaranteed, the rotation and detachment are not caused after the locking is ensured, and the safety is improved.

Drawings

FIG. 1 is an overall schematic diagram of a second multi-functional ladder according to an embodiment of the present invention;

fig. 2 is a schematic view of an outer ladder in a multifunctional ladder according to a second embodiment of the present invention;

FIG. 3 is a schematic view of an inner ladder of a second multi-functional ladder according to the embodiment of the present invention;

FIG. 4 is an enlarged schematic view of portion A of FIG. 3;

FIG. 5 is a schematic diagram showing the assembly of the step lock assembly and the inner ladder steps in the inner and outer ladder locking device according to the embodiment of the present invention;

FIG. 6 is an exploded view of the step lock assembly and the inner ladder steps in the inner and outer ladder locking device according to the embodiment of the present invention;

FIG. 7 is a perspective view of a step lock assembly in an inner and outer ladder locking device in accordance with an embodiment of the present invention;

FIG. 8 is an exploded view of the step lock assembly of the inner and outer ladder locking device according to an embodiment of the present invention;

fig. 9 is a schematic perspective view of a lock tongue in an inner and outer ladder locking device according to an embodiment of the present invention;

FIG. 10 is a front view of a tongue in an inner and outer ladder locking device in accordance with an embodiment of the present invention;

FIG. 11 is a right side view of the tongue in the inner and outer ladder locking device according to the embodiment of the present invention;

FIG. 12 is a schematic perspective view of a trigger in an inner and outer ladder locking device according to an embodiment of the present invention;

FIG. 13 is a right side view of the trigger in the inner and outer ladder locking device of an embodiment of the invention;

Fig. 14 is a schematic perspective view of an unlocking assembly in an inner and outer ladder locking device according to an embodiment of the present invention;

FIG. 15 is a schematic view of a step lock device in a locked state in an inner and outer ladder locking device according to an embodiment of the present invention;

FIG. 16 is a B-B cross-sectional view of FIG. 15;

FIG. 17 is a schematic view of an inner and outer ladder locking device of an embodiment of the present invention in a locked state;

FIG. 18 is a cross-sectional view taken along line C-C of FIG. 15;

FIG. 19 is a schematic view of an unlocking assembly of an inner and outer ladder locking device according to an embodiment of the present invention, wherein a rope is used as an unlocking connection portion;

FIG. 20 is a D-D sectional view of FIG. 15;

FIG. 21 is a schematic view of an outer ladder step in an inner and outer ladder locking device according to an embodiment of the invention;

FIG. 22 is a schematic diagram showing the assembly of the tread cavity assembly and the outer tread of the inner and outer tread locking device in accordance with an embodiment of the present invention;

FIG. 23 is a schematic diagram showing a combination of an inner ladder step and an outer ladder step in an inner and outer ladder locking device according to an embodiment of the present invention;

FIG. 24 is a schematic view of the outer ladder and the inner ladder in the inner and outer ladder locking device according to the embodiment of the present invention, wherein the lock tongue is separated from the cavity in the unlocked state of the outer ladder and the inner ladder, and the outer ladder is located above the inner ladder;

Fig. 25 is a schematic view of a locking device for an inner ladder and an outer ladder in an embodiment of the present invention, wherein a locking tongue is fixed in a cavity in a locked state of the inner ladder and the outer ladder;

Fig. 26 is a schematic view of the locking tongue falling out of the cavity in the unlocking state of the outer ladder and the inner ladder in the locking device of the inner ladder and the outer ladder, and the outer ladder is positioned below the inner ladder in the embodiment of the invention;

FIG. 27 is a schematic view showing the positions of the step lock assembly and the step chamber assembly in an unlocked state of the inner and outer ladder locking device according to an embodiment of the present invention;

Fig. 28 is a schematic view showing the positions of the step lock assembly and the step chamber assembly in a locked state of the inner and outer ladder locking device according to the embodiment of the present invention.

The parts of the above figures are shown as follows:

1. A step lock assembly;

11. a bolt; 111. a locking hole; 112. a swivel mounting hole; 113. a hinge hole;

12. A connecting base;

13. a connecting rod;

14. a trigger; 141. a trigger point; 142. a first notch; 143. a trigger hole; 144. a rotation action part;

15. a locking pin; 151. a limiting block is restored;

16. A first elastic member; 161. torsion spring seat;

17. A second elastic member;

18. A third elastic member;

19. a lock pin guide seat; 191. restoring the limit surface;

2. A step chamber assembly;

21. An inner plug; 211. a cavity; 2111. a bolt fixing groove;

22. A back cover plate; 221. a trigger part; 222 bolt limit points;

3. Unlocking the assembly;

31. Unlocking the rod; 311. unlocking the turning point;

32. Unlocking the connecting part;

33. Unlocking the force application part; 331. a handle; 332. a pull rope;

34. A pulley mechanism; 341. a pulley; 342. a pulley bracket;

35. unlocking the reset part; 351. a fourth elastic member;

36. Rope

4. An inner ladder; 41. inner ladder steps;

5. an outer ladder; 51. outer ladder steps; 52. rope fastener.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

Example 1

As shown in fig. 1 to 4, a first embodiment of the present invention provides an inner and outer ladder locking device for unlocking and locking an inner ladder 4 and an outer ladder 5, wherein the ladder columns of the outer ladder 5 are sleeved on the ladder columns of the inner ladder 4, a plurality of inner ladder steps 41 transversely arranged along the length direction of the ladder columns of the inner ladder 4 are arranged between the ladder columns of the inner ladder 4, and a plurality of outer ladder steps 51 corresponding to the inner ladder steps 41 are arranged between the ladder columns of the outer ladder 5.

As shown in fig. 5 to 14 and 23, the locking device of the first embodiment of the present invention comprises a step lock assembly 1, a step chamber assembly 2 and an unlocking assembly 3; wherein:

the stepping lock assembly 1 comprises a lock tongue 11, a connecting base 12, a connecting rod 13, a trigger 14 and a lock pin;

The connecting base 12 is used as a foundation of the pedal lock assembly 1 and is connected with the inner ladder pedal 41 in a positioning way; the connecting rod 13 and the lock tongue 11 are transversely hinged on the connecting base 12, and the lock tongue 11 rotates around the axis of the connecting rod 13; the lock tongue 11 is a block member hinged to the connecting rod 13, and the connecting rod 13 is positioned on the connecting base 12 so that the lock tongue 11 can rotate around the connecting rod 13; the first elastic piece 16 is arranged relative to the connecting base 12, and the first elastic piece 16 acts on the lock tongue 11 and forces the lock tongue 11 to stay in the middle position in the self rotation range;

The trigger 14 is a disc-shaped member, and a trigger point 141 and a trigger hole 143 are arranged on the disc-shaped member; the lock tongue 11 is provided with a locking hole 111 corresponding to the triggering hole 143, and a second elastic piece 17 is arranged opposite to the lock pin, and the second elastic piece 17 acts on the lock pin and forces the lock pin to move towards the locking hole 111 when the lock tongue 11 is in the middle position state;

a rotation action part 144 is arranged between the trigger 14 and the lock tongue 11, the trigger 14 is rotatably connected with the lock tongue 11 around the rotation action part 144, a third elastic member 18 is arranged relative to the rotation action part 144, and the third elastic member 18 acts on the trigger 14 and forces a trigger hole 143 of the trigger 14 to rotate towards a direction away from a locking hole 111 of the lock tongue 11;

The unlocking component 3 is a pulling mechanism acting on the lock pin, the pulling mechanism is connected with the lock pin and is used for pulling the lock pin out of the locking hole 111 and the triggering hole 143, the trigger 14 rotates relative to the lock pin 15 under the action of the third elastic piece 18 in the state that the lock pin is pulled out of the triggering hole 143, so that the triggering hole 143 of the trigger 14 deviates from the inserting position of the lock pin 15, and meanwhile, the side surface of the trigger 14 abuts against the lock pin 15 to prevent the insertion of the trigger 14, and the unlocking state that the lock tongue 11 can rotate along the connecting rod 13 is formed;

The tread cavity assembly 2 is arranged on the outer ladder tread 51, and the tread cavity assembly 2 is provided with a cavity 211 and a triggering part 221 which are correspondingly arranged; the cavity 211 corresponds to the lock tongue 11 in the stepping lock assembly 1 and is matched with the lock tongue 11 to extend into the cavity for realizing support and limit; the triggering part 221 corresponds to the triggering point 141 in the step lock assembly 1, when the outer step 51 reaches the locking position relative to the inner step 41, the triggering part 221 is abutted against the triggering point 141 and exerts a turning force, and the turning force overcomes the elastic force of the third elastic member 18 to enable the triggering hole 143 of the trigger 14 to be positioned at the inserting position of the locking pin 15, and in this state, the locking pin 15 is inserted into the locking hole 111 and the triggering hole 143 under the action of the second elastic member 17, so that the locking state of the step lock assembly 1 and the step cavity assembly 2 is formed.

Through implementation of the first embodiment, an inner and outer ladder locking device has an initial state, an unlocked state and a locked state, and the following three states are described in detail:

In the initial state, the lock pin 15 passes through the locking hole 111 to enable the lock tongue 11 and the trigger 14 to be relatively fixed, the lock tongue 11 is fixed in the cavity 211 of the stepping cavity assembly 2, and the relative positions of the inner ladder 4 and the outer ladder 5 are locked;

In the unlocking state, as shown in fig. 17 and fig. 18, the unlocking component 3 drives the lock pin 15 to pull out the locking hole 111 and the triggering hole 143, the trigger 14 rotates to enable the lock pin 15 to be separated from the locking hole 111, the trigger 14 props against the lock pin 15 to enable the lock pin 15 to enter the locking hole 111 through the triggering hole 143, the lock tongue 11 can freely rotate around the connecting rod 13, at the moment, the lock tongue 11 can be separated from the cavity 211 of the stepping cavity component 2, and the outer ladder 5 can move up and down along the length direction of the ladder post of the inner ladder 4 under the action of external force;

In the locked state, as shown in fig. 15 and 16, the lock tongue 11 abuts against the tread cavity assembly 2 and rotates against the acting force of the first elastic member 16, then enters the cavity 211 of the tread cavity assembly 2, the trigger 14 moves down to one side of the tread cavity assembly 2 together with the lock tongue 11, when the outer tread 51 reaches the locking position, the trigger 221 is tangent to the trigger point 141, the trigger 14 is pushed to rotate around the rotating part in the direction opposite to the acting force of the third elastic member, so that the lock pin 15 falls into the locking hole 111 under the acting force of the second elastic member 17, and the lock tongue 11 and the hinge rod remain relatively fixed and cannot rotate.

Through the implementation of the first embodiment, the implementation of the unlocking and locking functions is considered, convenience and smoothness of operation can be met, design standards to be met by the multifunctional ladder as a loading structure are considered, the structural characteristics of the original inner ladder step 41 and the original outer ladder step 51 are skillfully utilized, the step lock assembly 1 and the unlocking assembly 3 are integrated into the original structure of the inner ladder step 41, the step cavity assembly 2 is integrated into the original structure of the outer ladder step 51, after the inner ladder 4 and the outer ladder 5 are in the locking position, the locking state of the step lock assembly 1 and the step cavity assembly 2 is matched with the structures of the inner ladder 4 and the outer ladder 5, special design is carried out on the unlocking and locking processes in the locking device, in the unlocking process, after the locking pin 15 is pulled out by the unlocking assembly 3, the trigger 14 enables the trigger hole 143 to avoid the locking pin 15 and abut against the locking pin 15 under the action of the third elastic piece 18, the locking pin 11 is in a freely rotatable unlocking state, and in this state, the locking pin 11 is in the centering position under the action of the first elastic piece 16, and the locking pin 11 is in the centering position and the trigger state is enabled to be in the centering state and the locking pin 14 is enabled to be in the next to be in the movable state; when the outer ladder 5 moves to a proper position, the lock tongue 11 gradually enters the cavity 211, and the trigger point 141 in the trigger 14 is also contacted with the trigger part 221 in the stepping cavity assembly 2, so that the trigger 14 is pushed to rotate around the rotating action part 144, and the trigger hole 143 returns to the initial position, so that the lock pin 15 can return to enter the locking hole 111, and the lock tongue 11 is locked and cannot rotate. Therefore, it can be known that by adopting the technical scheme of the invention, the locking device is arranged on the inner ladder 4 and the outer ladder step 51 which are easy to be reached by hands, the use state of the multifunctional ladder is not considered when the unlocking is carried out, the constructor can unlock the ladder in the vertical state, the unlocking process is convenient and easy to operate, the fine and reasonable actions are completed by the cooperation of the mechanisms, the locking is ensured, the rotation and detachment can not be carried out after the locking is ensured, and the safety is increased.

In the first embodiment, the unlocking assembly 3 includes the unlocking lever 31, the unlocking connection portion 32 and the unlocking force applying portion 33, the unlocking lever 31 is mounted on the inner stair step 41 and has an unlocking rotation point 311 at one end of the inner stair step 41, the other end of the unlocking lever 31 is connected with the unlocking connection portion 32, the unlocking force applying portion 33 is connected with the unlocking connection portion 32, the unlocking connection portion 32 is connected with the lock pin 15, the unlocking force applying portion 33 is driven to rotate around the unlocking rotation point 311 and drive the unlocking connection portion 32 to move under the action of an external force, and the unlocking connection portion 32 drives the lock pin 15 to pull out the locking hole 111. The unlocking connection portion 32 is provided with a positioning pin and a connecting piece, and the unlocking connection portion 32 is connected with the lock pin 15 through the positioning pin and the connecting piece. The unlocking assembly 3 is used for unlocking the lock tongue 11, the trigger 14 is connected in parallel to ensure that the lock pin 15 cannot return in the unlocking state, smoothness of the outer ladder 5 in the up-down position adjustment in the unlocking state is ensured, and the unlocking operation is simple. Specifically, as shown in fig. 15, the unlocking assembly 3 further includes an unlocking reset portion 35, where the unlocking reset portion 35 includes a fourth elastic member 351, where the fourth elastic member 351 is a reset spring, one end of the reset spring is fixed to the unlocking connection portion 32, and the other end of the reset spring is connected to the connection base 12 or the inner ladder step 41, so as to form a movement trend of resetting the unlocking connection portion 32 relative to the initial position, and the increased unlocking reset portion 35 can prepare for the next unlocking of the unlocking assembly 3, the unlocking connection portion 32 can be reset in the locking process after unlocking, and the unlocking reset portion 35 and the second elastic member 17 can be linked to jointly complete resetting of the lock pin 15 and the unlocking connection portion 32.

More specifically, the unlocking force applying portion 33 is at least one of the handle 331 and the pull cord 332; wherein:

When the unlocking force applying part 33 is a handle 331, the handle 331 is disposed on the inward side of the inner ladder step 41 and is fixedly connected with the unlocking lever 31, the length direction of the handle 331 is consistent with the length direction of the unlocking lever 31, the handle 331 is adopted as the unlocking force applying part 33, as long as an operator stands on one side of the multifunctional ladder in an upright or flat state, the handle 331 is lifted by one hand, the step lock assembly 1 can be unlocked, the lock pin 15 is pulled out after the handle 331 is lifted, and the trigger 14 acts against the lock pin 15 at the moment, so that the lock tongue 11 is in a freely rotatable state;

When the unlocking force application part 33 is a pull rope 332, the pulley mechanism 34 is arranged on the other side of the turning point of the unlocking lever 31 on the inner ladder step 41, the pulley mechanism 34 comprises a pulley 341 and a pulley bracket 342, the pulley bracket 342 is fixedly connected with the unlocking lever 31, the pull rope 332 passes through the pulley 341 and then is connected with the unlocking connection part 32, a plurality of rope buckles 52 used for passing through the pull rope 332 are arranged on the ladder column of the outer ladder 5, and the rope buckles 52 are arranged along the length direction of the ladder column; when the pull cord 332 is used as the unlocking force applying portion 33, the operator can stand on the ladder steps to perform the height adjustment operation, in addition to the operation in which the operator stands on one side of the multifunctional ladder, the operation mode is as follows: on the step of the operator standing on one side of the ladder, the hand of the operator locks the stay cord 332 to unlock the step lock assembly 1 on the other side, after the step lock assembly 1 is unlocked, the stay cord 332 is continuously forced to enable the step lock assembly 1 and the step cavity assembly 2 to be misplaced into the next locking position, namely, the positions of the inner ladder 4 and the outer ladder 5 in the length direction are changed, the inner ladder step 41 is aligned with the next outer ladder step 51, at the moment, the stay cord 332 is loosened, and the step cavity assembly 2 on the outer ladder step 51 applies a force to the trigger 14 in the inner ladder step 41 lock assembly to lock the dead bolt 11, so that the adjustment of the height positions of the inner ladder 4 and the outer ladder 5 for one section is completed. The operator can finish the height adjustment of the multifunctional ladder without descending the ladder in the mode, the operation of the operator is utilized more, the climbing and descending are not needed, the multifunctional ladder is also beneficial to being suitable for various different occasions, and various requirements are met.

In the first embodiment, a locking hole 111 is formed in the lock tongue 11, and the locking hole 111 is provided for the lock pin 15 to pass through; the bolt 11 is provided with a rotary mounting hole 112 on the same side as the locking hole 111, and a rotary action part 144 is mounted in the rotary mounting hole 112; the hinge hole 113 is formed in the lock tongue 11, the connecting rod 13 penetrates through the hinge hole 113, the rotary mounting hole 112 and the locking hole 111 are located on the outer side of the circumference of the hinge hole 113, so that space is provided for rotation of the lock tongue 11 and rotation of the trigger 14, a reasonable position dislocation is formed between the locking hole 111 on the lock tongue 11 and the trigger hole 143 on the trigger 14, the trigger point 141 of the trigger 14 and the trigger part 221 of the stepping cavity assembly 2 are tangent and reset and rotate around the rotary action part 144, and the reset and rotation distance and path are reasonable. To facilitate insertion of the locking pin 15, the locking hole 111 is shaped as a combination of two semicircles plus a square, slightly providing a margin for positioning insertion of the locking pin 15.

In the first embodiment, the first elastic member 16 is formed by two sets of torsion springs, the torsion spring seat 161 is fixedly mounted at the middle portion of the connecting rod 13, the first elastic member 16 is disposed on the connecting rod 13 in a penetrating manner and is located in the torsion spring seat 161, one end of the first elastic member 16 abuts against the torsion spring seat 161, the other end abuts against the lock tongue 11, and the acting forces of the two sets of torsion springs in the first elastic member 16 are opposite in direction, so as to form a movement trend of resetting and centering the lock tongue 11 around the axis of the connecting rod 13. The action part of the first elastic piece 16 is formed by adopting two groups of torsion springs, the acting forces of the two groups of torsion springs are opposite, so that the lock tongue 11 can be always centered, the structure of the torsion springs is ingenious, the manufacturing cost is low, the assembly is convenient, the production cost and the production difficulty of the locking device can be reduced, the space layout of the stepping lock assembly 1 positioned on the inner ladder stepping 41 is also beneficial, the torsion spring seat 161 and the torsion springs are all sleeved on the transversely arranged connecting rod 13, and the space utilization is ingenious.

In the first embodiment, the lock pin guide seat 19 is disposed on one side of the connection base 12, the lock pin 15 is installed in the lock pin guide seat 19, the lock pin guide seat 19 is provided with a lock pin restoring mechanism, the lock pin 15 has a cylinder, the lock pin restoring mechanism includes a second elastic member 17, a restoring limiting block 151 disposed in the axial direction of the cylinder of the lock pin 15, a restoring limiting surface 191 disposed on the lock pin guide seat 19, the restoring limiting block 151 faces the outside of the lock pin 11, the restoring limiting surface 191 is disposed corresponding to the restoring limiting block 151, the restoring limiting surface 191 faces the inside of the lock pin 11, the second elastic member 17 is sleeved on the circumferential direction of the lock pin 15, one end of the second elastic member 17 abuts against the restoring limiting block 151, and the other end abuts against the restoring limiting surface 191, by adopting the lock pin restoring mechanism to force the lock pin 15 to move toward the locking hole 111 when the lock pin 11 is always located in the middle position, so as to ensure that the lock pin 15 is located in the middle and just in the cavity 211, and the lock pin 15 can be accurately, quickly and reliably locked when the lock is moved, swinging or flat when the lock is in the normal state, the lock assembly is unlocked by not in contact with the unlocking assembly 3.

In the first embodiment, the trigger point 141 is disposed on the outward side of the periphery of the trigger 14 and protrudes outward, the trigger 14 is further provided with a first notch 142, the first notch 142 is provided for the connecting rod 13 to pass through, the shape of the first notch 142 is arc-shaped, the first notch 142 is used as a limiting path of rotational displacement of the trigger 14, and the notch passes through the center position of the trigger 14, so that the rotational path of the trigger 14 is limited by the notch, the trigger 14 will not rotate too much when rotating around the rotating body under the action of the third elastic member 18, and the angle of the stressed rotation of the trigger point 141 on the trigger 14 when being interfered by the trigger portion 221 is just suitable, thereby further making the structures of the locking device more reasonable. Specifically, the trigger 14 is rotatably disposed on the outer side of the lock tongue 11, the third elastic member 18 has a first acting end and a second acting end, the first acting end acts on the trigger 14, and the second acting end acts on the lock tongue 11, so that the trigger 14 has a movement tendency of rotating around a turning point relative to the lock tongue 11 under the limiting action of the turning action portion 144 and the elastic deformation action of the third elastic member 18. The trigger aperture 143 is also arcuate in shape and the arcuate space allows for insertion of the locking pin 15 to provide a relatively large path and space for the relative locking position of the locking bolt 11 and trigger 14 when locked to be within a reasonable range.

In the first embodiment, the step cavity assembly 2 includes a back cover 22 and an inner plug 21, the inner plug 21 is provided with a cavity 211, the cavity 211 is provided with a latch fixing groove 2111 for supporting the latch 11 and meeting the load requirement, one side of the back cover 22 is provided with a latch limiting point 222 for fixing the latch 11 against falling out, the triggering portion 221 is located on the outer surface of the back cover 22, since the triggering point 141 of the trigger 14 protrudes outwards, the triggering portion 221 is the outer surface of the back cover 22, when the outer step 51 reaches the locking position, the back cover 22 is tangent to the triggering point 141 of the trigger 14, so as to push the trigger 14 to rotate.

Example two

The second embodiment of the invention also provides a multifunctional ladder, which comprises an inner ladder 4 and an outer ladder 5, and the multifunctional ladder further comprises the inner and outer ladder locking device in the technical scheme of the first aspect, wherein a step lock assembly 1, a step cavity assembly 2 and an unlocking assembly 3 are arranged between the outer ladder 5 and the inner ladder 4, the step lock assembly 1 and the unlocking assembly 3 are integrated into the original structure of the inner ladder step 41, and the step cavity assembly 2 is integrated into the original structure of the outer ladder step 51, so that the relative length adjustment of the outer ladder 5 and the inner ladder 4 is more convenient, smoother, safer and more reliable. A plurality of rope buckles 52 for penetrating through the pull ropes 332 are arranged at the upper and lower positions of the ladder columns of the outer ladder 5 and used for penetrating through the pull ropes 332, and when the outer ladder 5 is used for length adjustment, the pull ropes 332 are ensured to be long enough.

With respect to the above embodiments, the possible variations of the invention are described as follows:

1. In the above embodiment, as shown in fig. 8, the first elastic member 16 adopts a torsion spring, the second elastic member 17 adopts a return spring, and the third elastic member 18 adopts a torsion spring, but the embodiment of the present invention is not limited thereto, and other elements that can also use elastic deformation to make the respective elastic members have a tendency to move toward their respective acting ends or acting positions, such as a pressure spring tube, a torsion spring, an elastic hard sponge, etc., will be understood and accepted by those skilled in the art, and thus the description of the relevant mechanism will not be repeated.

2. In the above embodiment, the unlocking force applying portion 33 in the unlocking module 3 is at least one of the handle 331 and the pull cord 332, preferably both of them are used, so that the unlocking can be performed by the handle 331 or the pull cord 332, and the embodiment of the invention is not limited thereto, and only one of them can be used to achieve good unlocking and locking.

3. In the above embodiment, as shown in fig. 15, the unlocking connection portion 32 of the unlocking component 3 is provided with a positioning pin and a connecting piece, and the unlocking connection portion 32 is connected with the locking pin 15 through the positioning pin and the connecting piece, but the embodiment of the invention is not limited thereto, and as shown in fig. 19 and 20, a rope 36 may be directly connected to the locking pin 15, and the rope 36 pulls the locking pin 15 to disengage from the locking hole 111 and the triggering hole 143; of course, other ways of composing the unlocking assembly 3 are not limited in this embodiment, and other structures that can smoothly pull out the lock pin 15 and can reset the lock pin 15 after releasing the second elastic member 17 without limitation may be adopted.

4. In the above embodiment, as shown in fig. 12, an outwardly protruding trigger point 141 may be disposed in the trigger 14, and the trigger point 141 cooperates with a trigger portion 221 in the tread chamber assembly 2 to perform the locking action, where the trigger portion 221 is located on the outer surface of the rear cover 22; however, the embodiment of the present invention is not limited thereto, and the trigger point 141 may be set by providing a concave portion with an acting point in the trigger 14, and then designing a linkage component in the stepping chamber assembly 2 as the trigger portion 221, where the trigger portion 221 can contact with the trigger point 141 of the concave portion in the trigger 14 and apply a turning force against the third elastic member 18 after the locking tongue 11 enters the cavity 211, so as to complete the corresponding action.

5. In the above embodiment, as shown in fig. 12, the rotation fixing portion is integrally fixed with the trigger 14, and the rotation acting portion 144 may be a cylinder integrally formed with the trigger 14 of the disc member, but the embodiment of the invention is not limited thereto, and the rotation acting portion 144 may be set on the lock tongue 11 or separately set, and then the rotation acting portion 144 and the trigger 14 are relatively and fixedly connected, so that the same actions and effects can be achieved.

The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.

Claims (11)

1. An inner ladder locking device and an outer ladder locking device are used for unlocking and locking an inner ladder (4) and an outer ladder (5), wherein a ladder column of the outer ladder (5) is sleeved on a ladder column of the inner ladder (4), a plurality of inner ladder steps (41) transversely arranged along the length direction of the ladder column of the inner ladder (4) are arranged between the ladder columns of the inner ladder (4), and a plurality of outer ladder steps (51) corresponding to the inner ladder steps (41) are arranged between the ladder columns of the outer ladder (5), and the inner ladder locking device is characterized in that:

The locking device comprises a stepping lock assembly (1), a stepping cavity assembly (2) and an unlocking assembly (3); wherein,

The stepping lock assembly (1) comprises a lock tongue (11), a connecting base (12), a connecting rod (13), a trigger (14) and a lock pin (15);

the connecting base (12) is used as a foundation of the step lock assembly (1) and is in positioning connection with the inner ladder steps (41); the connecting rod (13) and the lock tongue (11) are transversely hinged on the connecting base (12), and the lock tongue (11) rotates around the axis of the connecting rod (13); the lock tongue (11) is a block-shaped member hinged on the connecting rod (13), and the connecting rod (13) is positioned on the connecting base (12) so that the lock tongue (11) can rotate around the connecting rod (13); the first elastic piece (16) is arranged relative to the connecting base (12), and the first elastic piece (16) acts on the lock tongue (11) and forces the lock tongue (11) to be in a middle position in the self rotation range;

The trigger (14) is a disc-shaped member, and a trigger point (141) and a trigger hole (143) are arranged on the disc-shaped member; the lock tongue (11) is provided with a locking hole (111) corresponding to the triggering hole (143), a second elastic piece (17) is arranged relative to the lock pin (15), and the second elastic piece (17) acts on the lock pin (15) and forces the lock pin (15) to move towards the locking hole (111) when the lock tongue (11) is in a middle position state;

A rotary action part (144) is arranged between the trigger (14) and the lock tongue (11), and the trigger (14) is rotationally connected with the lock tongue (11) around the rotary action part (144); a third elastic member (18) is arranged relative to the turning action part (144), and the third elastic member (18) acts on the trigger (14) and forces the trigger hole (143) of the trigger (14) to rotate towards a direction away from the locking hole (111) of the lock tongue (11);

The unlocking component (3) is a pulling mechanism acting on the lock pin (15), the pulling mechanism is connected with the lock pin (15) and is used for pulling the lock pin (15) out of the locking hole (111) and the triggering hole (143), the trigger (14) rotates relative to the lock pin (15) under the action of the third elastic piece (18) in the state that the lock pin (15) is pulled out of the triggering hole (143), so that the triggering hole (143) of the trigger (14) deviates from the inserting position of the lock pin (15), and meanwhile, the side surface of the trigger (14) abuts against the lock pin (15) to prevent the lock pin from being inserted, so that an unlocking state that the lock tongue (11) can rotate along the connecting rod (13) is formed;

The stepping cavity assembly (2) is arranged on the outer ladder stepping (51), and the stepping cavity assembly (2) is provided with a cavity (211) and a triggering part (221) which are correspondingly arranged; the cavity (211) corresponds to the lock tongue (11) in the stepping lock assembly (1) and is matched with the lock tongue (11) to extend into the cavity for realizing support and limit; the triggering part (221) corresponds to a triggering point (141) in the stepping lock assembly (1), when the outer stepping (51) reaches a locking position relative to the inner stepping (41), the triggering part (221) props against the triggering point (141) and exerts a turning force, and after overcoming the elastic force of the third elastic piece (18), the triggering hole (143) of the trigger (14) is positioned at the inserting position of the lock pin (15), and in this state, the lock pin (15) is inserted into the locking hole (111) and the triggering hole (143) under the action of the second elastic piece (17), so that the locking state of the stepping lock assembly (1) and the stepping cavity assembly (2) is formed.

2. An inner and outer ladder locking device as set forth in claim 1, wherein: the unlocking component (3) comprises an unlocking rod (31), an unlocking connecting part (32) and an unlocking force application part (33), wherein the unlocking rod (31) is arranged on the inner ladder step (41) and is provided with an unlocking rotary point (311) at one end of the inner ladder step (41), and the other end of the unlocking rod (31) is connected with the unlocking connecting part (32); the unlocking force application part (33) is connected with the unlocking connection part (32), the unlocking connection part (32) is connected with the lock pin, the unlocking rod (31) is driven to rotate around the unlocking rotation point (311) under the action of external force on the unlocking force application part (33), the unlocking connection part (32) is driven to move, and the lock pin is driven by the unlocking connection part (32) to outwards pull out the locking hole (111).

3. An inner and outer ladder locking device as set forth in claim 2, wherein: the unlocking force application part (33) is at least one of a handle (331) and a pull rope (332); wherein,

When the unlocking force application part (33) is a handle (331), the handle (331) is arranged on the inward side of the inner ladder step (41) and is fixedly connected with the unlocking rod (31), and the installation length direction of the handle (331) is consistent with the length direction of the unlocking rod (31);

When the unlocking force application part (33) is a pull rope (332), a pulley mechanism (34) is arranged on the other side of an unlocking rotary point (311) of the unlocking rod (31) on the inner ladder step (41), the pulley mechanism (34) comprises a pulley (341) and a pulley bracket (342), the pulley bracket (342) is fixedly connected with the unlocking rod (31), the pull rope (332) passes through the pulley (341) and then is connected with the unlocking connection part (32), and a plurality of rope buckles (52) used for passing through the pull rope (332) are arranged at the upper and lower positions of a ladder column of the outer ladder (5).

4. An inner and outer ladder locking device as set forth in claim 2, wherein: the unlocking assembly (3) further comprises an unlocking reset part (35), the unlocking reset part (35) comprises a fourth elastic piece (351), the fourth elastic piece (351) is a reset spring, one end of the reset spring is fixed with the unlocking connecting part (32), and the other end of the reset spring is connected with the connecting base (12) or the inner ladder step (41) to form a movement trend that the unlocking connecting part (32) resets relative to the initial position.

5. An inner and outer ladder locking device as set forth in claim 1, wherein: the lock tongue (11) is provided with a rotary mounting hole (112) on the same side of the locking hole (111), and a rotary action part (144) is mounted in the rotary mounting hole (112); the lock tongue (11) is provided with a hinge hole (113), the hinge hole (113) passes through the connecting rod (13), and the rotary mounting hole (112) and the locking hole (111) are positioned on the circumferential outer side of the hinge hole (113).

6. An inner and outer ladder locking device as set forth in claim 1, wherein: the spring seat (161) is fixedly arranged at the middle part of the connecting rod (13), the first elastic piece (16) is arranged on the connecting rod (13) in a penetrating mode and is positioned in the spring seat (161), one end of the first elastic piece (16) is abutted against the spring seat (161), the other end of the first elastic piece is abutted against the spring bolt (11), acting force directions of the two groups of the spring bolts in the first elastic piece (16) are opposite, and the spring bolt (11) is formed to return and center around the axis of the connecting rod (13).

7. An inner and outer ladder locking device as set forth in claim 1, wherein: one side of the connecting base (12) is provided with a lock pin guide seat (19), a lock pin (15) is arranged in the lock pin guide seat (19), a lock pin recovery mechanism is arranged on the lock pin guide seat (19), the lock pin (15) is provided with a cylinder, the lock pin recovery mechanism comprises a second elastic piece (17), a recovery limiting block (151) arranged on the axis of the cylinder of the lock pin (15) and a recovery limiting surface (191) arranged on the lock pin guide seat (19), the recovery limiting block (151) faces the outer side of the lock tongue, the recovery limiting surface (191) corresponds to the recovery limiting block (151), the recovery limiting surface (191) faces the inner side of the lock tongue, the second elastic piece (17) is sleeved on the circumference of the lock pin (15), one end of the second elastic piece (17) is propped against the recovery limiting block (151), and the other end of the second elastic piece (17) is propped against the recovery limiting surface (191).

8. An inner and outer ladder locking device as set forth in claim 1, wherein: the trigger point (141) is arranged on the outward side of the trigger (14) in the circumferential direction and protrudes outwards; the trigger (14) is also provided with a first notch (142), the first notch (142) is used for the connecting rod (13) to pass through, the shape of the first notch (142) is arc-shaped, and the first notch (142) is used as a limit path for the rotational displacement of the trigger (14).

9. An inner and outer ladder locking device as set forth in claim 8, wherein: the trigger (14) rotates and sets up in the outside of spring bolt, and third elastic component (18) have first action end and second action end, and first action end is acted on trigger (14), second action end is acted on spring bolt (11), makes trigger (14) have the pivoted motion trend of pivot point for spring bolt (11) under the spacing effect of gyration action portion (144) and the elastic deformation effect of third elastic component (18).

10. An inner and outer ladder locking device as set forth in claim 9, wherein: the pedal cavity assembly (2) comprises a rear cover plate (22) and an inner plug (21), wherein a cavity (211) is formed in the inner plug (21), a lock tongue fixing groove (2111) for supporting the lock tongue (11) and meeting the load requirement is formed in the cavity (211), a lock tongue limiting point (222) for fixing the lock tongue (11) and preventing the lock tongue from falling off is formed in one side of the rear cover plate (22), and a triggering part (221) is located on the outer surface of the rear cover plate (22).

11. The utility model provides a multi-functional ladder, multi-functional ladder includes interior ladder and outer ladder, its characterized in that: the multi-function ladder further comprising an inner and outer ladder locking device of any one of claims 1 to 10.