GB2480117A

GB2480117A - A brake unit suitable for a stroller

Info

Publication number: GB2480117A
Application number: GB1019790A
Authority: GB
Inventors: Hai Bo Zeng
Original assignee: Wonderland Nurserygoods Co Ltd Hong Kong
Current assignee: Wonderland Nurserygoods Co Ltd Hong Kong
Priority date: 2010-05-05
Filing date: 2010-11-23
Publication date: 2011-11-09
Anticipated expiration: 2030-11-23
Also published as: CN201721490U; GB2480117B; GB201019790D0

Abstract

A braking device arranged on a frame is provided, said device comprises: a first wheel assembly 110 arranged on one side of the frame S provided with a first braking unit (350, figure 3), a second wheel assembly 120 and braking unit on the other side of the frame, and a stepping assembly 130 on the frame between the first and second wheel assemblies, wherein the stepping assembly includes a pedal, a first traction element, such as a cable (240a), and a second traction element, wherein one end of the first traction element is connected to the pedal (figure 8) and the other end is connected to the first braking unit (figure 6), while the second traction element similarly links the pedal and the second braking unit, when the pedal is moved with respect to the frame, the first and second braking units are driven so that the first and second wheel assemblies can be switched between a locked state and an unlocked state. The pedal may be pivotally attached to the frame, and may form part of a stroller brake mechanism suitable for transversely folding strollers.

Description

BRAKING DEVICE AND STROLLER UTILIZING THE SAME

Field of the Invention

The present invention generally relates to a braking device. More particularly, the present invention relates to a braking device for a stroller.

Background of the Invention

As the manufacturing technology for strollers progresses, more and more designs for improving convenience of use are developed. For example, the current stroller is normally equipped with a braking device arranged on its rear wheels so that a user can operate the braking device promptly and easily. In so many designs for the braking device, a design referred to as "one-step brake" is very popular due to its convenient one-action operation. However, the conventional one-step brake cannot be applied to a lightweight stroller of the laterally-foldable type since the conventional one-step brake is operated by directly driving the braking rods on both sides. Accordingly, it is desirable to develop a one-step brake for such lightweight strollers.

Summary of the Invention

In view of the above problems, one object of the present invention is to provide a braking device arranged on a frame, comprising: a first wheel assembly arranged on one side of the frame and provided with a first braking unit, a second wheel assembly arranged on the other side of the frame and provided with a second braking unit, and a stepping assembly arranged on the frame and between the first wheel assembly and the second wheel assembly, wherein the stepping assembly includes a pedal, a first traction element and a second traction element, wherein one end of the first traction element is connected to the pedal and the other end of first traction element is connected to the first braking unit, while one end of the second traction element is connected to the pedal and the other end of second fraction element is connected to the second braking unit, when the pedal is moved with respect to the frame, the first braking unit and the second braking unit are driven by the pedal through the first traction element and the second traction element, respectively, so that the first wheel assembly and the second wheel assembly can be switched between a locked state and an unlocked state.

According to the braking device of the invention, the pedal can be switched between a first position and a second position with respect to the frame, so that the first wheel assembly and the second wheel assembly are switched between the locked state and the unlocked state.

According to the braking device of the invention, the stepping assembly further includes a connecting element fixed on the frame, wherein the connecting element is provided with a positioning element, wherein the pedal is connected to the connecting element and is provided with a coupling element which is corresponding to the positioning element in shape, wherein the positioning element and the coupling element can be engaged with each other to selectively position the pedal to a first position or a second position so that the first wheel assembly and the second wheel assembly can be switched between the locked state and the unlocked state.

According to the braking device of the invention, the pedal is pivotally connected to the connecting element so that the pedal can be turned between the first position and the second position with respect to the connecting element.

According to the braking device of the invention, the positioning element is cylindrical and includes at least a first positioning portion, the coupling element is formed as a hollow cylinder for accommodating the positioning element, and the coupling element has at least a second positioning portion for engaging with the first positioning portion.

According to the braking device of the invention, the positioning element includes at least a first positioning portion formed as a protrusion, and the coupling element includes a second positioning portion formed as a pair of concaves for engaging with the first positioning portion.

According to the braking device of the invention, each of the first wheel assembly and the second wheel assembly includes a wheel base, wherein the first braking unit and the second braking unit are slidably arranged within the respective wheel bases.

According to the braking device of the invention, each of the first braking unit and the second braking unit includes a sliding piece and a braking pin fixed onto the sliding piece, the sliding pieces are connected with the first traction element and the second traction element, respectively.

According to the braking device of the invention, each of the first wheel assembly and the second wheel assembly includes an elastic element, wherein ends of the elastic element are abutted against the wheel base and the braking unit, respectively, to bias the braking pin towards a locked position.

Another object of the present invention is to provide a stroller including a frame and a braking device, the braking device comprising: a first wheel assembly arranged on one side of the frame and provided with a first braking unit, a second wheel assembly arranged on the other side of the frame and provided with a second braking unit, and a stepping assembly arranged on the frame and between the first wheel assembly and the second wheel assembly, wherein the stepping assembly includes a pedal, a first traction element and a second traction element, wherein one end of the first traction element is connected to the pedal and the other end of first fraction element is connected to the first braking unit, while one end of the second traction element is connected to the pedal and the other end of second traction element is connected to the second braking unit, when the pedal is moved with respect to the frame, the first braking unit and the second braking unit are driven by the pedal through the first traction element and the second traction element, respectively, so that the first wheel assembly and the second wheel assembly can be switched between a locked state and an unlocked state.

According to the sfroller of the invention, the pedal can be switched between a first position and a second position with respect to the frame, so that the first wheel assembly and the second wheel assembly are switched between the locked state and the unlocked state.

According to the stroller of the invention, the stepping assembly further includes a connecting element fixed on the frame, wherein the connecting element is provided with a positioning element, wherein the pedal is connected to the connecting element and is provided with a coupling element which is corresponding to the positioning element in shape, wherein the positioning element and the coupling element can be engaged with each other to selectively position the pedal to a first position or a second position so that the first wheel assembly and the second wheel assembly can be switched between the locked state and the unlocked state.

According to the stroller of the invention, the pedal is pivotally connected to the connecting element so that the pedal can be turned between the first position and the second position with respect to the connecting element. j

According to the stroller of the invention, the positioning element is cylindrical and includes at least a first positioning portion, the coupling element is formed as a hollow cylinder for accommodating the positioning element, and the coupling element has at least a second positioning portion for engaging with the first positioning portion.

According to the stroller of the invention, the positioning element includes at least a first positioning portion formed as a protrusion, and the coupling element includes a second positioning portion formed as a pair of concaves for engaging with the first positioning portion.

According to the stroller of the invention, each of the first wheel assembly and the second wheel assembly includes a wheel base, wherein the first braking unit and the second braking unit are slidably arranged within the respective wheel bases.

According to the stroller of the invention, each of the first braking unit and the second braking unit includes a sliding piece and a braking pin fixed onto the sliding piece, the sliding pieces are connected with the first traction element and the second traction element, respectively.

According to the stroller of the invention, each of the first wheel assembly and the second wheel assembly includes an elastic element, wherein ends of the elastic element are abutted against the wheel base and the braking unit, respectively, to bias the braking pin towards a locked position.

The present invention has achieved an advantageous effect of providing a braking device which can be promptly locked or unlocked. Especially, such a braking device is suitable for general strollers or lightweight strollers of the laterally-foldable type.

Brief Description of the Drawings

These and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a three dimensional view of a braking device according to an embodiment of present invention; Fig. 2 is an exploded view for a stepping assembly of the braking device according to the present invention; Fig. 3 is an exploded view for a first wheel assembly of the braking device according to the embodiment of present invention; Fig. 4A and 4B show an unlocked state and a locked state for the first wheel assembly of the braking device according to the embodiment of the present invention, respectively; Fig. 5 is a diagram illustrating the assembled internal components of a wheel base of the braking device according to the embodiment of the present invention; Fig. 6 is a sectional view for the wheel base of the braking device according to the embodiment of the present invention; Fig. 7 is a three dimensional view showing the backside of a pedal of the braking device according to the embodiment of the present invention; Fig. 8A shows a state diagram for the stepping assembly in which the braking device according to the embodiment of the present invention is in a locked state, and Fig. 8B is a corresponding sectional view of Fig. 8A; and Fig. 9A shows a state diagram for the stepping assembly in which the braking device according to the embodiment of the present invention is in an unlocked state, and Fig. 9B is a corresponding sectional view of Fig. 9A.

Detailed Description of the Preferred Embodiment

A preferred embodiment for a braking device according to the invention is described with reference to the drawings as follows.

Refer firstly to Fig. 1, which illustrates an embodiment of a braking device 100 according to the invention. In this embodiment, the braking device 100 is arranged on a stroller, wherein the stroller comprises a frame S with side frames on both sides thereof. The braking device 100 comprises a first wheel assembly 110 arranged on one side frame of the frame S, a second wheel assembly 120 arranged on the other side frame of the frame S, and a stepping assembly 130 arranged on the frame S and between the first wheel assembly 110 and the second wheel assembly 120.

In the braking device 100 according to the invention, the first wheel assembly 110 and the second wheel assembly 120 are symmetrically designed, and thus will have identical components. For simplicity, only the first wheel assembly 110 is described as an example.

Fig. 2 is an exploded view for the stepping assembly 130 of the braking device 100 according to an embodiment of the invention. As shown in the figure, the stepping assembly 130 comprises a connecting element 210 fixed on the frame S of the stroller. The connecting element 210 comprises a connecting portion 215 fixed on the frame S and a positioning element 220 extended from the connecting portion 215, wherein, in this embodiment, one side of the connecting portion 215 is formed as U-shape to be mounted onto the frame S. The positioning element 220 is cylindrical with its two opposite sides including first positioning portions 225 that is formed as a protrusion in this embodiment. The positioning portions 25 are adapted to facilitate securing the braking device 100 in a locked state or an unlocked state. Besides, the stepping assembly 130 further comprises a pedal 230, a first traction element 240A and a second traction element 240B, the pedal 230 is pivotally connected to the connecting element 210 by a fastening element 250. As shown in Fig. 2 and Fig. 3, one end of the first traction element 240A and one end of the second traction element 240B are connected to right side and left side of the pedal 230, respectively; while the other end of first traction element 240A and the other end of second traction element 240B are connected to a braking unit 350 within the first wheel assembly 110 and the second wheel assembly 120, respectively. The first traction element 240A and the second traction element 240B are made of steel wire and clothed with axial cover for protection.

Fig. 3 is an exploded view for the first wheel assembly 110 of the braking device according to an embodiment of the invention. As shown in the figure, the first wheel assembly 110 comprises a wheel base 310 connected to the side frame, a wheel axle 320 passing through the wheel base 310, and wheels 330 connected with the wheel axle 320. The first wheel assembly 110 further comprises an elastic element 340, a braking unit 350 and a shock-absorbing spring 370 arranged within the wheel base 310 (the arrangement of these elements will be further described by reference to Fig. 5 and Fig. 6). The braking unit 350 includes a sliding piece 3501 and a braking pin 3502 fixed onto the sliding piece 3501, wherein the other end of the first traction element 240A (as shown in Fig. 2) is connected to the sliding piece 3501. In addition, the wheel base 310 includes a hollow portion 314 for receiving of sliding piece 3501, and two slots 312 provided on the opposite walls of the hollow portion 314. A plurality of grooves 335 are formed on the hubs of the wheels 330 to be engaged with the braking pin 3502 so that the braking function is realized. In this embodiment, there are two wheels 330 arranged on both sides of the wheel base 310, respectively. However, one wheel is also applicable in other embodiments.

The assembled first wheel assembly 110 is shown in Fig. 4A and Fig. 4B, wherein Fig. 4A illustrates the unlocked state of the first wheel assembly 110 when the braking pin 3502 is disengaged from the grooves 335, and Fig. 4B illustrates the locked state of the first wheel assembly 110 when the braking pin 3502 is engaged with the grooves 335.

In the following, the internal structure of the assembled first wheel assembly 110 is described by reference to Fig. 5 and Fig. 6. As shown, the first traction element 240A as well as the elastic element 340, the sliding piece 3501 and the braking pin 3502 arranged within the wheel base 310 have been completely assembled. In Fig. 5, the other end of the first traction element 240A has been lodged in the sliding piece 3501 (refer to the sectional view of Fig. 6). Besides, the braking pin 3502 passes through the sliding piece 3501, wherein the junctions thereof are finished by texture processing to achieve the effect of tight combination. Next, refer to the sectional view of the wheel base 310 of Fig. 6. In Fig. 6, after assembling, the elastic element 340, the sliding piece 3501, the middle part of braking pin 3502 and the other end of the first traction element 240A as shown in Fig. 5 are arranged within the hollow portion 314 of the wheel base 310, and the braking pin 3502 sticks out of the wheel base 310 through the slots 312. The braking pin 3502 is slidable along the slots 312 so that the braking unit 350 is slidably arranged within the wheel base 310 and is movable between an unlocked position and a locked position with respect to the wheel base 310. In addition to the braking pin 3502, the wheel axle 320 also sticks out of the wheel base 310 to facilitate fixing of the two wheels 330 on both sides of the wheel base 310. The two ends of the elastic element 340 are abutted against the wheel base 310 and the sliding piece 3501, respectively, to bias the braking pin 3502 towards the locked position. The two ends of shock-absorbing spring 370 are abutted against the wheel base 310 and the side frame of the frame S, respectively, to provide cushioning for the wheels 330.

Fig. 7 shows the three dimensional view of the backside of the pedal 230, to facilitate explaining the assembling of the first traction element 240A, the second traction element 240B and the pedal 230. As shown in the figure, the center of the pedal 230, with correspondent to the connecting element 210, is provided with a coupling element 232 for accommodating the positioning element 220, and fixing portions 234, 236 located besides the coupling element 232. In this embodiment, the coupling element 232 is formed as a hollow cylinder for accommodating the positioning element 220, with second positioning portions 238 provided on the inner side walls thereof. In this embodiment, each of the second positioning portion 238 is formed of a pair of concaves, while each of the fixing portions 234, 236 contains a slit T. More specifically, one end of the first traction element 240A is embedded through the slit T of the fixing portion 234, and one end of the second traction element 240B is embedded through the slit T of the fixing portion 236. Besides, the pedal 230 is pivotally connected to connecting element 210 so that the pedal 230 can be rotatable between a first position and a second position with respect to the connecting element 210 (to be detailed in the following).

Next, the operational principle of the braking device according to the invention will be explained by reference to Fig. 4A, Fig. 4B, Fig. 5, Fig. 6, Fig. 8A, Fig. 8B, Fig. 9A and Fig. 9B, wherein Fig. 8A shows a view when the pedal 230 of the stepping assembly 130 is at the first position, and Fig. 8B is a corresponding sectional view of Fig. 8A; while Fig. 9A shows a view when the pedal 230 of the stepping assembly is at the second position, and Fig. 9B is a corresponding sectional view of Fig. 9A.

As shown in Fig. 8A and Fig. 8B, the pedal 230 is retained at the first position by engagement between the first positioning portions 225 of the positioning element 220 with one of concaves of the second positioning portions 238 of the coupling element 232, and both of the first traction element 240A and the second traction element 240B are in a loose state (i.e., the ends of these two traction elements are not pulled by the external force). Meanwhile, it is appreciated by referring to Fig. 4B and Fig. 6 that the braking unit 350 connected to the other end of the first traction element 240A within the first wheel assembly 110 (and, similarly, the one that connected to the other end of the second traction element 240B within the second wheel assembly 120) is pushed by the elastic force of the elastic element 340 so that the braking pin 3502 is moved downward to the locked position and engaged with one of the grooves of the wheels, thereby putting the wheel assemblies in the locked state.

To unlock the braking device, a force Fl as shown in Fig. 8A is applied on one side of the pedal 230, so that the pedal 230 is rotated with respect to the connecting element 210 to force the positioning element 220 and the coupling element 232 to come off their original engaging positions. n this manner, the pedal 230 is turned clockwise to pull the first traction element 240A and the second traction element 240B until the pedal 230 is located at the second position, as shown in Fig. 9A and Fig. 9B, wherein the first positioning portions 225 of the positioning element 220 is engaged with the other concave of the second positioning portions 238 of the coupling element 232. Meanwhile, the braking unit 350 connected to the other end of the first traction element 240A within the first wheel assembly 110 (and, similarly, the one that connected to the other end of the second traction element 240B within the second wheel assembly 120) is also pulled so that the braking pin 3502 is moved upward and thus disengaged from the grooves 335 of the wheels, thereby putting the first wheel assembly 110 in the unlocked state as shown in Fig. 4A (similarly, the second wheel assembly 120 will also be in the unlocked state).

On the contrary, to unlock the braking device when it is in the unlocked state as shown in Fig. 9A, a force F2 as shown is applied on the other side of the pedal 230, so that the pedal 230 is turned with respect to the connecting element 210 to force the positioning element 220 and the coupling element 232 to come off their original engaged positions. In this manner, the pedal 230 is turned counterclockwise to move the first traction element 240A and the second traction element 240B until the pedal 230 is located at the first position, as shown in Fig. 8A and Fig. 8B, wherein the first positioning portions 225 of the positioning element 220 is engaged with the the concave of the second positioning portions 238 of the coupling element 232.

Meanwhile, by the elastic force of the elastic element 340, the braking unit 350 is pushed downward so that the braking pin 3502 is moved downward to re-engaged with one of the grooves of the wheels, thereby putting the first wheel assembly 110 in the locked state as shown in Fig. 4B (similarly, the second wheel assembly 120 will also be in the locked state).

While the present invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. Therefore, it is intended that the invention will include all embodiments falling within the scope of the appended claims.

Claims

What We Claim Is: 1. A braking device arranged on a frame, comprising: a first wheel assembly arranged on one side of the frame and provided with a first braking unit, a second wheel assembly arranged on the other side of the frame and provided with a second braking unit, and a stepping assembly arranged on the frame and between the first wheel assembly and the second wheel assembly, wherein the stepping assembly includes a pedal, a first traction element and a second traction element, wherein one end of the first traction element is connected to the pedal and the other end of first traction element is connected to the first braking unit, while one end of the second traction element is connected to the pedal and the other end of second traction element is connected to the second braking unit, when the pedal is moved with respect to the frame, the first braking unit and the second braking unit are driven by the pedal through the first traction element and the second traction element, respectively, so that the first wheel assembly and the second wheel assembly can be switched between a locked state and an unlocked state.
2. The braking device of claim 1, wherein the pedal is rotatable relative to the frame between a first position and a second position, so that the first wheel assembly and the second wheel assembly are switched between the locked state and the unlocked state.
3. The braking device of claim 1, wherein the stepping assembly further includes a connecting element fixed on the frame, wherein the connecting element is provided with a positioning element, wherein the pedal is connected to the connecting element and is provided with a coupling element corresponding to the positioning element, wherein the positioning element and the coupling element can be engaged with each other to selectively position the pedal to a first position or a second position so that the first wheel assembly and the second wheel assembly can be switched between the locked state and the unlocked state.
4. The braking device of claim 3, wherein the pedal is pivotally connected to the connecting element so that the pedal can be rotated between the first position and the second position with respect to the connecting element.
5. The braking device of claim 3 or 4, wherein the positioning element is cylindrical and includes at least a first positioning portion, the coupling element is formed as a hollow cylinder for accommodating the positioning element, and the coupling element has at least a second positioning portion for engaging with the first positioning portion.
6. The braking device of claim 3 or 4, wherein the positioning element includes at least a first positioning portion formed as a protrusion, and the coupling element includes a second positioning portion formed as a pair of concaves for engaging with the first positioning portion.
7. The braking device of any above claims, wherein each of the first wheel assembly and the second wheel assembly includes a wheel base, wherein the first braking unit and the second braking unit are slidably arranged within the respective wheel bases.
8. The braking device of claim 7, wherein each of the first braking unit and the second braking unit includes a sliding piece and a braking pin fixed onto the sliding piece, the sliding pieces are connected with the first traction element and the second traction element, respectively.
9. The braking device of claim 8, wherein each of the first wheel assembly and the second wheel assembly includes an elastic element, wherein ends of the elastic element are abutted against the wheel base and the braking unit, respectively, to bias the braking pin towards a locked position.
10. The braking device of any above claims, wherein the first traction element and the second traction element is steel wire.
11. A braking device substantially as hereinbefore described with reference to and illustrated on the accompanying drawings 12. A stroller including a frame and a braking device, the braking device comprising: a first wheel assembly arranged on one side of the frame and provided with a first braking unit, a second wheel assembly arranged on the other side of the frame and provided with a second braking unit, and a stepping assembly arranged on the frame and between the first wheel assembly and the second wheel assembly, wherein the stepping assembly includes a pedal, a first traction element and a second traction element, wherein one end of the first traction element is connected to the pedal and the other end of first traction element is connected to the first braking unit, while one end of the second traction element is connected to the pedal and the other end of second fraction element is connected to the second braking unit, when the pedal is moved with respect to the frame, the first braking unit and the second braking unit are driven by the pedal through the first traction element and the second traction element, respectively, so that the first wheel assembly and the second wheel assembly can be switched between a locked state and an unlocked state.13. The stroller of claim 12, wherein the pedal is rotatable relative to the frame between a first position and a second position, so that the first wheel assembly and the second wheel assembly are switched between the locked state and the unlocked state.14. The stroller of claim 12, wherein the stepping assembly further includes a connecting element fixed on the frame, wherein the connecting element is provided with a positioning element, wherein the pedal is connected to the connecting element and is provided with a coupling element corresponding to the positioning element, wherein the positioning element and the coupling element can be engaged with each other to selectively position the pedal to a first position or a second position so that the first wheel assembly and the second wheel assembly can be switched between the locked state and the unlocked state.15. The stroller of claim 14, wherein the pedal is pivotally connected to the connecting element so that the pedal can be rotated between the first position and the second position with respect to the connecting element.16. The stroller of claim 14 or 15, wherein the positioning element is cylindrical and includes at least a first positioning portion, the coupling element is formed as a hollow cylinder for accommodating the positioning element, and the coupling element has at least a second positioning portion for engaging with the first positioning portion.17. The stroller of claim 14 or 15, wherein the positioning element includes at least a first positioning portion formed as a protrusion, and the coupling element includes a second positioning portion formed as a pair of concaves for engaging with the first positioning portion.18. The stroller of any of claims 12-17, wherein each of the first wheel assembly and the second wheel assembly includes a wheel base, wherein the first braking unit and the second braking unit are slidably arranged within the respective wheel bases.19. The stroller of claim 18, wherein each of the first braking unit and the second braking unit includes a sliding piece and a braking pin fixed onto the sliding piece, the sliding pieces are connected with the first traction element and the second traction element, respectively.20. The stroller of claim 19, wherein each of the first wheel assembly and the second wheel assembly includes an elastic element, wherein ends of the elastic element are abutted against the wheel base and the braking unit, respectively, to bias the braking pin towards a locked position.21. The stroller of any of claims 12-20, wherein the first traction element and the second traction element is steel wire.22. A stroller substantially as hereinbefore described with reference to and illustrated in the accompanying drawings Amendments to the (claims have been filed as follows Claims 1. A braking device arranged on a frame, comprising: a first wheel assembly arranged on one side of the frame and provided with a first braking unit, a second wheel assembly arranged on the other side of the frame and provided with a second braking unit, and a stepping assembly arranged on the frame and between the first wheel assembly and the second wheel assembly, wherein the stepping assembly includes a pedal, a first traction element and a second traction element, wherein one end of the first traction element is connected to the pedal and the other end of first traction element is connected to the first braking unit, while one end of the second traction element is connected to the pedal and the other end of second traction element is connected to the second braking unit, when the pedal is moved with respect to the frame, the first braking unit and the second braking unit are driven by the pedal through the first traction element and the second traction element, respectively, so that the first wheel assembly and the second wheel assembly can be switched between a locked state and an unlocked state wherein the stepping assembly further includes a connecting element fixed on the frame, wherein the connecting element is provided with a positioning element, wherein the pedal is connected to the connecting element and is provided with a coupling element corresponding to the positioning element, wherein the positioning element and the coupling element can be engaged with each other to selectively position the pedal to a first position or a second position so that the first wheel assembly and the second wheel assembly can be switched between the locked state and the unlocked state, and wherein the positioning element includes at least a first positioning portion formed as a protrusion, and the coupling element includes a second positioning portion formed as a pair of concaves for engaging with the first positioning portion.2. The braking device of claim 1, wherein the pedal is rotatable relative to the frame between a first position and a second position, so that the first wheel assembly and the second wheel assembly are switched between the locked state and the unlocked state.3. The braking device of claim 1, wherein the pedal is pivotally connected to the connecting element so that the pedal can be rotated between the first position and the second position with respect to the connecting element.4. The braking device of claim 1 or 3, wherein the positioning element is cylindrical and includes at least a first positioning portion, the coupling element is formed as a hollow cylinder for accommodating the positioning element, and the coupling element has at least a second positioning portion for engaging with the first positioning portion.5. The braking device of any above claims, wherein each of the first wheel assembly and the second wheel assembly includes a wheel base, wherein the first braking unit and the second braking unit are slidably arranged within the respective wheel bases.6. The braking device of claim 5, wherein each of the first braking unit and the second braking unit includes a sliding piece and a braking pin fixed onto the sliding piece, the sliding pieces are connected with the first traction element and the second traction element, respectively.7. The braking device of claim 6, wherein each of the first wheel assembly and the second wheel assembly includes an elastic element, wherein ends of the elastic element are abutted against the wheel base and the braking unit, respectively, to bias the braking pin towards a locked position.8. The braking device of any above claims, wherein the first traction element and the second traction element is steel wire.9. A braking device substantially as hereinbefore described with reference to and illustrated on the accompanying drawings 10. A stroller including a frame and a braking device, the braking device comprising: a first wheel assembly arranged on one side of the frame and provided with a first braking unit, a second wheel assembly arranged on the other side of the frame and provided with a second braking unit, and a stepping assembly arranged on the frame and between the first wheel assembly and the second wheel assembly, wherein the stepping assembly includes a pedal, a first traction element and a second traction element, wherein one end of the first traction element is connected to the pedal and the other end of first traction element is connected to the first braking unit, while one end of the second traction element is connected to the pedal and the other end of second traction element is connected to the second braking unit, when the pedal is moved with respect to the frame, the first braking unit and the second braking unit are driven by the pedal through the first traction element and the second traction element, respectively, so that the first wheel assembly and the second wheel assembly can be switched between a locked state and an unlocked state wherein the stepping assembly further includes a connecting element fixed on the frame, wherein the connecting element is provided with a positioning element, wherein the pedal is connected to the connecting element and is provided with a coupling element corresponding to the positioning element, wherein the positioning element and the coupling element can be engaged with each other to selectively position the pedal to a first position or a second position so that the first wheel assembly and the second wheel assembly can be switched between the locked state and the unlocked state, and wherein the positioning element includes at least a first positioning portion formed as a protrusion, and the coupling element includes a second positioning portion formed as a pair of concaves for engaging with the first positioning portion.11. The stroller of claim 10, wherein the pedal is rotatable relative to the frame between a first position and a second position, so that the first wheel assembly and the second wheel assembly are switched between the locked state and the unlocked state.
12. The stroller of claim 10, wherein the pedal is pivotally connected to the connecting element so that the pedal can be rotated between the first position and the second position with respect to the connecting element.
13. The stroller of claim 10 or 12, wherein the positioning element is cylindrical and includes at least a first positioning portion, the coupling element is formed as a hollow cylinder for accommodating the positioning element, and the coupling element has at least a second positioning portion for engaging with the first positioning portion.
14. The stroller of any of claims 10-13, wherein each of the first wheel assembly and the second wheel assembly includes a wheel base, wherein the first braking unit and the second braking unit are slidably arranged within the respective wheel bases.
15. The stroller of claim 14, wherein each of the first braking unit and the second braking unit includes a sliding piece and a braking pin fixed onto the sliding piece, the sliding pieces are connected with the first traction element and the second traction element, respectively.
16. The stroller of claim 15, wherein each of the first wheel assembly and the second wheel assembly includes an elastic element, wherein ends of the elastic element are abutted against the wheel base and the braking unit, respectively, to bias the braking pin towards a locked position.
17. The stroller of any of claims 10-16, wherein the first traction element and the second traction element is steel wire.
18. A stroller substantially as hereinbefore described with reference to and illustrated on the accompanying drawings Co