WO2010146005A1 - Reliably operating lifter for nursing beds - Google Patents

Abstract

In a nursing bed (1), the upper and the lower frame (41) are mutually connected through a total of four pairs of articulated levers (44, 45). The movements on one side of the bed are synchronized by means of a horizontal coupling location. The coupling location is also hinged to the hinge of the articulated levers (49). In order to configure said hinge (49) so that it operates in a reliable manner, the articulated levers (44, 45) are placed on bearing bushes (57, 61) which are tightly screwed to the horizontal coupling location.

Description

 Process-safe lifter for care beds

A well-known from practice nursing bed has a base, in which the upper and the lower frame of the base are connected to each other via four arranged at the corners of a rectangle toggle pairs. The toggle levers of a pair are connected to the knee joint via a screw. To kinematically couple the toggle pairs on one side of the bed, there is a horizontal coupling strut on each side. The horizontal coupling strut is connected to the knee joints of the toggle pairs of the respective bed side. The coupling strut is sandwiched between the levers of the respective toggle lever pair. The axis at this point forms a through-bolt which passes with the required manufacturing tolerance, i. the diameter of the screw is smaller than the diameter of the hole.

In order to move the two frames of the lifter according to the height of each other or towards each other, extending between the lower and the upper frame, an inclined linear drive. This causes a horizontal force between the two frames, which is absorbed by an oblique coupling strut on each side of the bed. For this purpose, the upper toggle lever of a toggle lever pair is coupled to the lower lever of the other toggle lever pair on the same side of the bed. As a result of the oblique dome strut, asymmetrical forces arise in the region of the knee joints on the screws, which lead to a tilting of the screws in the bores corresponding to the radial and axial play. The play in the knee joints allows the toggle pairs to buckle differently depending on the load, which in turn leads to a tilt occurs due to a load on the upper frame relative to the lower frame according to the location of the load. When a patient sits down on one side of the bed, because of the elasticity and the play in the knee joints, the side of the bed in question will lower more than the opposite side, which is not loaded.

To reduce this sinking, i. To increase the stiffness in the vertical direction, the mutually corresponding levers on both sides of the lower frame via a torsion shaft torsionally rigid coupled. The same applies to a set of levers on the upper frame.

Due to the aforementioned tilting, however, the toggle pairs may buckle differently on one side of the bed. This is prevented in the known bed by the serving as hinge pins screws are tightened with a predetermined tightening torque. As a result, the lever and the horizontal coupling strut are placed in the region of the knee joint with a defined axial biasing force against each other, which on the one hand prevents tilting and on the other hand allows a good transfer of forces in the direction of the flat side of the lever. Such forces occur when the bed is loaded, for example, in the raised position in the transverse direction near the foot end or in the vicinity of the head end, so that in the upper frame relative to the subframe, a torque is introduced with respect to a vertical axis. The flat-lying levers in the region of the knee joint provide a rigid connection that allows a small lateral deflection. The mentioned stresses occur eg during massages.

A disadvantage of the known solution is compliance with the prescribed tightening torque in the knee joints. In addition, the bias changes over the life of the bed because the existing in the knee joints on the lever color is gradually abraded, so that the axial biasing force disappears.

Proceeding from this, it is an object of the invention to provide a solution in which the lifter is reliable to produce in the knee joints.

This object is achieved by the nursing bed with the features of claim 1.

The new nursing bed has a multi-part mattress topper, which forms a head end and a foot end. Under the mattress overlay is a height-adjustable bed lifter, which has a standing on the bottom subframe and a siphon head on which the mattress pad is arranged. The upper frame and the lifter head are connected by a lifting mechanism. Two levers are provided on each side of the bed lifter. This creates a hanging down from the lifter head upper lever at the head end and a hanging down from the lifter head lever at the foot. Furthermore, arises by the arrangement of an upstanding from the subframe lever on Head end and a lever protruding from the subframe at the foot end. The free from the respective frame distal ends of the lever on one side of the bed are connected to each other via a knee joint or knee hinge. The knee joints of the toggle pairs on each side of the bed are also connected to each other via a coupling strut to synchronize the movements of the toggle pairs on the respective side of the bed.

The horizontal coupling strut lies at each end between the toggle levers of the respective toggle lever pair. For height adjustment of the lifter, a linear drive is provided which extends between the sub-frame and the lifter head. The resulting horizontal force is compensated by an inclined coupling strut on each side of the bed. The oblique coupling strut connects an upper lever of a toggle lever pair with a lower lever of the other toggle lever pair on the relevant side.

The toggle levers of each toggle lever pair are provided with a bearing bore in the area of the knee joint. In each bearing bore is a socket. The two sockets are bolted rigidly to the respective end of the respective horizontal coupling strut with the aid of a through-bolt on each knee joint. In addition, the bushings in the bearing bores of the toggle lever have an axial play. Due to the axial play and the fact that the sockets are screwed to the horizontal coupling strut, a tight tightening the through-bolt is sufficient. Compliance with a prescribed tightening torque is no longer required. It has surprisingly been found that in the new type of knee joint in the area of the lifter, the flexibility and stiffness is as good as in the known lifter, in which the arms are pressed against each other surface with a predetermined pressure force. Although the respective levers on the bearing bush have both an axial play and necessarily a tilt play, because the bearing bore must be larger than the outer diameter of the bearing bush, the stiffness of the known solution is comparable. The comparability of the stiffness relates to both torques about the vertical axis at any height and the stiffness of the knee joints with respect to the vertical force. The well-known lifter does not sag much under load despite the relatively loose connection in the region of the respective knee joint as the known lifter. After prolonged use, ie a corresponding number of cycles, the new solution is even significantly superior to the known solution.

It is advantageous if at both ends of each bushing large-scale starting discs are present. As a result, the ratios remain largely constant regardless of the bending angle. In particular, it is prevented that the lever damage the coating in case of severe buckling.

Advantageously, the bearing bushes can be made of bearing bronze.

As bushings simple cylindrical bushings can be used.

Favorable conditions arise when the outer diameter of the bearing bush is approx. 14 mm and the drilling in the bushing about 10 mm. The fits between the bearing bush and the bearing bore in the relevant lever can be generously dimensioned and allow a tilting clearance of, for example, up to 2 °.

The bearing bores in the levers in the region of the knee joint need not have an axial extension, for example in the form of riveted bushes or welded tubular extensions. It suffices a lever strength of about 6 mm to 12 mm, preferably by 10 mm. This wall thickness is required in heavy duty beds due to the buckling forces occurring at the knee levers to ensure adequate safety.

Even an axial clearance of more than 0.4 mm proves to be harmless.

Incidentally, developments of the invention are the subject of subclaims.

The following description of the figures explains aspects for understanding the invention. Further, not described details, the expert can refer to the drawings in the usual way, the extent to complement the description of the figures. It is clear that the invention is not limited to the illustrated embodiment, but includes all modifications that are familiar to those skilled in the study of the description of the figures.

The following drawings are not necessarily to scale. To illustrate details, certain areas may be exaggerated. In addition, the drawings are strikingly kindled and do not contain every practical guidance from ^¬ optional detail. The terms "up" and "down" or "front" and "back" or "right" and "left" refer to the normal position of use or the terminology in beds.

In the drawing, an embodiment of the object of the invention is shown.

Fig. 1 shows an inventive rotary bed in the lying position.

Fig. 2 shows the rotary bed of Figure 1 in the chair - or sitting position.

Fig. 3 shows the bed lifter of the nursing bed in a side view, partially exploded.

4 shows an example of one of the knee lever hinges in an exploded view.

Figure 1 shows a perspective view of a nursing bed 1 in the lying position, while Figure 2 shows the nursing bed 1 in the seat or chair position.

The nursing bed 1 has a Bettumrandung 2 with a head part 3, a foot part 4 and side walls 5 and 6. The viewer facing side wall 5 is located in the reclining position as illustrated at a distance from the ground, so there is a gap between the lower edge of the side wall 5 and the bottom, which allows the nursing staff to deliver the toes under the bed. The side wall 5 is movably mounted and arrives in the chair position of the nursing bed 1 in a downwardly shifted position, as shown in Figure 2 reveals. The special mounting of the side wall 5 is detailed in DE 199, for example

12 937 A 1 explained.

Within the Bedumrandung 2 is a bed lift 7, as it can be seen in Figure 3.

To the bed lifter 7 include a height-adjustable base 8, on top of which a rotary hinge 9 is fixed with a vertical axis of rotation, an intermediate frame 10, and a reclining frame 11, on which a mattress 12 is located. The reclining frame 11 is rectangular in plan view.

The reclining frame 11 is divided into a central portion 13 which is fixedly connected to the intermediate frame 10, a back portion 14 which at the central portion

13 is hinged, a thigh portion 15, which is also hinged to the central portion 13, and a lower leg portion 16. The lower leg portion 16 is hinged to the distal end of the central portion 13 of the thigh portion 15. The hinge axes about which the sections 14, 15, 16 are movable relative to the central section 13 are horizontal. Finally, the foot frame 11 still has a foot portion 17 which is rigidly connected directly to the base 8.

The central portion 13 of the reclining frame 11 has two mutually parallel longitudinal bars 18, which are spaced apart according to the width of the nursing bed 1. Because of the lateral view of the obscured visible longitudinal beam 18 behind it the associated longitudinal spar of the Zewntralabschnitts 13. Each of these bars 18 ends at hinge plates for a hinge, the structure of which is described in DE 102 50 075 Al. This document is hereby incorporated by reference.

Each spar 18 carries inwardly facing pins on which rubber pieces are pushed, which absorb spring rods in a known manner. Instead of spring rods can serve as a support and a plate, as is common in hospital beds.

The back portion 14 is bounded by a spar 19 and a further parallel spar, which is not visible because of the representation in Figure 3. The spar 19 is hinged to the spar 18 while the other concealed spar is connected to the longitudinal spar 18 parallel to the longitudinal beam. The two spars 19 of the back portion 14 are connected to each other via a not visible in the figure cross member at the upper end at 20. In addition, a further transverse strut 21 connects the two longitudinal members 19 at the bottom.

Also, the thigh portion 15 is limited by two longitudinal beams, of which only a longitudinal beam 22 can be seen. The other longitudinal spar is covered by the longitudinal spar 22. The two longitudinal struts 22 are connected by a transverse strut 23. The cross strut 26 extends approximately at the center of each longitudinal spar 22 at the bottom.

Finally, the lower leg portion 16 is bounded by two longitudinal beams, of which in turn only the longitudinal beam 24 can be seen in the figure. The two Longitudinal members 24 are connected together at the lower end at 25 via an unrecognizable transverse strut. In addition to this transverse strut, the two longitudinal bars 24 are connected by a strut 26, are fastened to the two mutually parallel guide rails 27, which extend to the end 25. As shown, they extend at an angle to the longitudinal beam 24 in such a way that they converge in the direction of the foot end 25. The distance between the two guide rails 27 is significantly smaller than the distance between the two longitudinal beams 24. Opposite these, the guide rails 27 are offset approximately 20 cm inwards.

All of the longitudinal members 19, 22, and 24 bear pins pointing towards the middle of the bed in order to connect rubber molded parts to the longitudinal members 19, 22, and 24, between which spring rods extend in a known manner.

The hinges connecting adjacent longitudinal beams 18, 19, 22, 24 on each side of the bed 1 are shown schematically at 29, 30 and 31.

The lower leg portion 16 may be raised or lowered via an unillustrated electric motor. The electric motor is coupled by a gear 32 and is located in the intermediate frame 10th

Another electric motor 33 is supported in the intermediate frame 10 and leads to the cross brace 21. In this way, the back portion 14 can be raised or lowered.

The two longitudinal members 18 of the central part 13 are rigidly connected to the intermediate frame 10. The intermediate frame 10 is composed of a square frame welded together square tubes, of which only a square tube 34 can be seen. The parallel square tube is hidden by the square tube 34.

The rectangular frame is narrower than the distance between the longitudinal members 18 corresponds to each other. At the mutually parallel square tubes 34 a total of four arms 35 are welded, of which two each carry a longitudinal beam 18. The booms 35 are horizontal and perpendicular to the longitudinal axis of the nursing bed. 1

The rotary hinge 9 connects the intermediate frame 10 with the height-adjustable base 8. It consists of a ring 36 and a rotatably mounted in the ring 34 turntable 37 together. The fifth wheel 37 is bolted to the intermediate frame 10 via screws, not shown. The exact structure of the rotary hinge 9 is explained in DE 102 50 075 A1, to which reference is made here.

By means of the rotary hinge 9 of the intermediate frame 10 is rotatable together with the reclining frame 11 with respect to a vertical axis of rotation. The turning geschient by means of an electric motor 38, which is supported at one end to the base 8 and other nenden on the turntable 37.

To the height-adjustable base 8 include an upper frame 39 and a frame under 41, which consist of correspondingly welded with each other square tubes, two of which form parallel square tubes longitudinal bars 39a and 41a. Over a total of four toggle pairs 42 and 43, the upper frame 39 is supported on the lower frame 41. The rotary hinge is connected to the upper frame 39.

The toggle pairs 42, 43 are each located next to a longitudinal side of the base 8, so that the corresponding toggle pairs 42, 43 on the other longitudinal side in the side view of Figure 3 are not visible.

The toggle lever pair 42, 43 is composed of an upper toggle lever 44 and a lower toggle 45. Each knee lever 42, 43 is hingedly connected to the upper and lower frames 39, 41, respectively, via a horizontal axis hinge 46 on the respective side of the bed. All axes of the hinges 46 are parallel to each other. The hinges 46 are coaxial with their axes to the axes of the hinges of the unrecognizable toggle 42, 43. For the purpose of supporting and improving rigidity, the toggle levers corresponding to each other may be connected to each other at both sides by a torsion shaft, i. the left lever 45 is coupled to the left lever 45 on the other side of the bed via the torsion shaft, etc. These torsion shafts lie between the 39a and 41a. The axes of rotation of the torsion waves are indicated at 46 and 47, respectively.

The two toggle pairs 42, 43 on each side of the base 8 are each coupled by an associated horizontal coupling strut 48 with each other. Each coupling strut 48 is, as shown, hingedly connected to the knee joint 49 of each toggle lever pair 42,43.

Finally, on each side of the base 8, a sloping coupling strut 50 connects the upper knee inarm 44 of the toggle lever pair 42 with the lower toggle arm 45 of the toggle lever pair 43.

Em electric motor 51, which is designed as the electric motors 33, 38 as a spindle motor, extending between the upper frame 39 and the sub-frame 41. It is articulated next to the toggle 42 at a dashed lines indicated transverse strut 52 of the lower frame 41. Its other end is hinged to a concealed transverse strut of the upper frame 39, next to the toggle lever 43. The motor thus lies directly between the two frames 39 and 41, pointing to the oblique coupling strut 50.

The toggle 42, 43 act together with the horizontal coupling strut 48 and the oblique coupling strut 50 as a kind of parallel guide for the relative movement of the two frames 39 and 41. The drive via the Spindelhubmotor 51, which lifts the reclining frame 11 when extending and when retracting the Lying frame 11 lowers.

The Spindelhubmotor 51 is installed centrally between the two frames 39 and 41, i. it lies in a vertical plane, which also contains the bed longitudinal axis.

When the bed is loaded on one side, there is an unbalanced load which tends to tilt the upper frame 39 with respect to the lower frame 41 to the point of loading at the rear. The necessary bearing clearance and manufacturing tolerances also allow actual tilting. Because of the inclined coupling strut 50, which receives the horizontal force of the Spindelhubmotors 51, in the region of the knee hinges 49 are the forces on both sides of the horizontal coupling strut 50 is not equal. In the prior art, attempts have been made to reduce this tilting by using 49 through bolts as the hinge axles for the knee lever hinges, which pass through corresponding bearing bores with a small clearance and are tightened with a prescribed torque. This prevents tilting and lateral forces can also be transmitted well.

Unfavorable here, however, is the observance of the prescribed tightening torque, which changes on top of that because of the wear.

Fig. 4 shows a new solution in which a defined tightening is not required. FIG. 4 exemplarily illustrates one of the knee joints or knee hinges 49 in an exploded view.

The toggle arm 45 includes a bearing bore 56 near its end. The diameter of the bearing bore 56 is sized to receive a bushing 57 with little play. The length of the bearing bush 57 is greater than the thickness of the toggle lever 45 by up to 0.4 mm.

In the horizontal coupling strut 58, a through hole 58 is included at the respective end. The diameter of the bearing bore 58 corresponds to the clear width / inner diameter of the bearing bush 57.

Similar to the lower toggle arm 45, the upper toggle arm 44 is also provided with a bearing bore 59, whose inside diameter is the outer diameter of a bearing bush 61 corresponds. The length of the bearing bush 61 is again about 0.4 mm greater than the thickness of the Kniehebelarms 44 measured in the axial direction of the bearing bush 61. the bushings 57 and 61 are equal.

In the assembled state 61 two washers 62 and 63 are still present on both sides of the bearing bush, between which in the assembled state sandwich the respective end of the toggle lever 44 is located. Corresponding starting discs are also provided for the bearing bush 57, but not drawn for reasons of clarity.

The hinge is held together with a through-bolt 64, in which the shaft diameter of the clear width of the bearing bushes 57 and 61 and the through hole 58 corresponds.

The knee lever hinge 49 is mounted so that the washer 64 is attached to the screw 64 and the bearing bush 61. Then the screw 64 is inserted into the bearing bush and the washer 62 pushed. The further imports of the screw 64 causes the screw shaft passes through the bore 58. On the exiting end of a washer corresponding to the washer 62 is attached, then the bearing bush 57. On the bearing bush 57 of the toggle lever 45 is pushed. On the outside of the Kniehebelarms 45 a washer corresponding to the washer 63 is attached and then the entire structure is screwed together with a nut, not shown. The mother is tightened.

After assembly, the two toggle arms 44 and 45 on their bushings 57 and 61, both an axial clearance of the order of up to 0.4 mm and a radial clearance according to the manufacturing tolerances. The radial clearance is such that tilting of the toggle lever arms 44, 45 on the associated bearing bushes 57 and 61 does not exceed approximately 2 °. Such a fit is a so-called clearance fit, which does not place high demands on the production tolerance.

The new solution eliminates the defined tightening of the through-bolt in the knee joint.

The new solution eliminates the defined tightening of the through-bolt in the knee joint. Because of the axial play, a flat contact or a flat compression in the area of the knee joint is dispensed with. It has surprisingly been found that despite the considerable tolerances, the rigidity of the connection between the upper frame 39 and the lower frame 41 is not impaired. This applies both with regard to forces which generate a torque about the vertical axis between the two frames as well as with respect to vertical forces which act on the outside of the frame and are thus offset from the engagement force by the spindle lifting motor 51.

In the new solution, simple through holes are sufficient as bearing bores in the toggle lever arms, the only condition being that the walls are sufficiently smooth. The tolerance can be far. In particular, it is not necessary that the toggle lever arms in the region of the bearing bores have additional reinforcements in the thickness.

In addition, the bushings, as shown, simple cylindrical smooth bushings be without collar, which reduces the cost of production, because it is sufficient to cut off simple tubes. Overrunning to create a fret is not required.

In a nursing bed, the upper and the lower frame are connected by a total of four toggle pairs. The movements on one side of the bed are synchronized by a horizontal coupling point. The coupling point is also hinged to the knee lever hinge.

To make this hinge process-reliable, the toggle levers sit on bearing bushes which are firmly bolted to the horizontal coupling point.

Claims

Claims: 1. nursing bed (1) with a multipart mattress support (7), which has a head end and a foot end, with a height-adjustable bed lifter (7) having a bottom frame (41) standing on the floor and a lifter head (39) on which the mattress overlay (11) is arranged, with a lever mechanism (42, 43, 48, 50) which connects the subframe (41) to the lifting head (39) and which belongs to the side of the bed lifter (7), a head end and a foot end under levers (45), both of which are articulated at their lower ends to the subframe (41) and each having a bearing bore (56, 59) at their free upper ends, a head-side and a foot-side upper lever (44) both of which are pivotally hinged at their upper ends to the jack head (39) and each having a bearing bore (56, 59) at their free lower ends; - A horizontal coupling strut (48) extending with one end between the free ends of the head-side lever (44) and with the other end between the free ends of the foot-side lever (45) and pivotally connected to the levers (44,45) is connected, including the coupling strut (48) at the respective end includes a through hole (58), - An inclined coupling strut (50) which connects an upper lever (44) with a lower lever (45) and which is pivotally connected in the region between the ends of the respective lever (44,45), wherein through each bearing bore (56,58) in the levers (44,45) performs a bushing (57,51), such that at each end of the horizontal coupling strut (48) on both sides of the coupling strut (48) each have a socket ( 57, 61), and through the two bushings (57, 61) at each end of the coupling strut (48) and the bore (58) in the coupling strut (48) passes through a bolt (64) with which the bushings (57 , 61) are clamped against the horizontal coupling strut (48), and wherein the bushings (57,661) in the bearing bores (56,59) of the levers (44,45) have an axial play, and with a linear drive (51) leading from the subframe (41) to the lifter head (39). 2. Nursing bed according to claim 1, characterized in that mutually corresponding hinge axes on the two sides of the lever mechanism (42,43,48,50) are coaxial with each other. 3. Nursing bed according to claim 1, characterized in that at least one lever (44,45) on one side of the lever mechanism (42,43,48,50) and the corresponding lever (44,45) on the other side of the lever mechanism (42,43,48,50) with a common torsion element (53) are connected in order to minimize a rotation of the lever (44,45) against each other under unequal load. 4. Nursing bed according to claim 1, characterized in that the bearing bushes (57,51) consist of bearing bronze. 5. Nursing bed according to claim 1, characterized in that between the end of the respective toggle lever (44,45) and the horizontal coupling strut (48) a shim (62,63) is inserted through the bearing bush (57,51) is clamped against the horizontal coupling strut (48). 6. Nursing bed according to claim 1, characterized in that the position bushings (57,51) are simple cylindrical bushings which have no collar. 7. Nursing bed according to claim 1, characterized in that the bearing bush (57,51) has an outer diameter between 12 mm and 16 mm, preferably 14 mm. 8. Nursing bed according to claim 1, characterized in that the Kniehebelarm (44,45) has a thickness, measured in the direction of the hinge axis, which is between 8 mm and 12 mm, preferably 10 mm. 9. nursing bed according to claim 1, characterized in that the toggle lever (44,45) on the bearing bush (57, 61) has an axial play of between 0.1 mm and 0.8 mm, preferably around 0.4 mm. 10. Nursing bed according to claim 1, characterized net, that the toggle lever (44,45) forms a clearance with the bearing bush (57,51). 11. Nursing bed according to claim 1, characterized in that the Kniehebelarm (44,45) on the bearing bush (57,51) is tiltable by an angle between 0.5 ° and 2 °.