NL2013394B1

NL2013394B1 - Joint assembly for a stroller.

Info

Publication number: NL2013394B1
Application number: NL2013394A
Authority: NL
Inventors: Yme Leijenaar Sybren; Bastiaan Van Tongeren Jeroen; Jovanovic Petar
Original assignee: Royalty Bugaboo Gmbh
Priority date: 2014-09-01
Filing date: 2014-09-01
Publication date: 2016-09-26

Abstract

There is provided a joint assembly for a joint assembly comprising a shaft (13) and a shaft gear (6) arranged on the shaft in a non-rotatable way. The shaft gear comprises teeth arranged in a ring at a circumference of the shaft gear and extending in a first co-axial direction parallel to a main axis of the shaft (13). A coupling element (8) is arranged for rotatably coupling a first bar (108) to the shaft (13). The coupling element (8) comprises a disc shaped part and an elongated connection part for receiving the first bar. The disc shaped part comprises teeth (85) arranged in a second ring concentric with respect to a central opening . The teeth (85) are aligned with an the opposing teeth (61) of the shaft gear (6). A fixation element (5) comprises a plurality of teeth (52). Each of the teeth of the fixation element is arranged to enter a recess between teeth of the first and second plurality of teeth, so that the fixation element (5) in an engaged state disables a rotation of the first coupling element (8) relative to the shaft gear (6).

Description

FIELD OF THE INVENTION

The invention relates to a joint assembly and to a transporting device for person and/or luggage comprising such a joint assembly.

BACKGROUND ART

Published US patent application US2008/0088116 A1 describes a buggy comprising a frame on which a carrier for a child can be placed. The frame comprises front and rear wheels, two handle bars, two front wheel bars which support the front wheels, two rear wheel bars which support the rear wheels, and two supporting pins for supporting the carrier.

The frame further comprises coupling members which comprise front wheel bar discs, rear wheel bar discs, supporting discs and handle bar discs. The handle bar and the supporting pins are fixed in such a way that the front wheel bar discs and the rear wheel bar discs can be turned relative to one another about a pivot axis. The front wheel bar discs and the rear wheel bar discs can be turned relative to one another about the pivot axis, wherein the coupling members can each be locked in one or more positions in which the front wheel bars and the rear wheel bars are fixed relative to one another, and can also be unlocked from these positions. A disadvantage of the coupling members is that the play between interlocking parts, necessary for locking and unlocking movement of the respective parts and play between locking parts caused by production tolerances, causes unwanted play between the bars, even in a locked state.

SUMMARY OF THE INVENTION

One of the objects of the invention is to provide an improved joint assembly for a transporting device such as a stroller.

An aspect of the invention provides a joint assembly comprising a shaft and a shaft gear arranged on the shaft in a non-rotatable way, the shaft gear comprising a first plurality of teeth arranged in a first ring at a circumference of the shaft gear and extending in a first co-axial direction parallel to a main axis of the shaft. The assembly also comprises a first coupling element arranged for rotatably coupling a first bar to the shaft, the first coupling element comprising a disc shaped part and a connection part. The disc shaped part comprises a central opening for receiving the shaft gear and comprising a second plurality of teeth arranged in a second ring at a circumference of the central opening and extending in the first co-axial direction. Each of the second plurality of teeth is aligned with an associated tooth of the first plurality of teeth of the shaft gear.

The joint assembly comprises a fixation element arranged on the shaft and comprising a third plurality of teeth arranged in a third ring and extending in a second co-axial direction parallel to the main axis of the shaft but reversed from the first coaxial direction, wherein each of the third plurality of teeth is arranged to enter a recess between teeth of the first and second plurality of teeth, so that the fixation element in an engaged state disables a rotation of the first coupling element relative to the shaft gear.

In an embodiment, the joint assembly is part of a frame of a stroller to transport a child or a baby. A handlebar is coupled to the shaft via the first coupling element. The orientation of the handlebar can be changed stepwise with respect to the shaft by moving the fixation element from an engaged state into a disengaged state and back. Due to the interconnecting teeth of the fixation element and the other teeth, the handle bar is backlash free with respect to the other parts of the stroller frame once the handlebar is set to a fixed orientation.

In an embodiment, each of the first, second and third plurality teeth is tapered and symmetrical with respect to a plane of symmetry, wherein the main axis of the shaft lies, at least in use, in the plane of symmetry. Each of the first, second and third plurality teeth may have two opposing side walls which are flat and tilted towards each other. The degree of tilt of the opposing side walls may be the same for teeth of both the first, second and third plurality of teeth to obtain an optimal coupling between the elements.

In the engaged state each of the third plurality of teeth (i.e. the teeth of the fixation element) is forced into a recess between two neighboring teeth of the shaft gear and the first coupling element. In a preferred embodiment both side walls of each of the third plurality of teeth contacts a respective side wall of the two neighboring teeth of the shaft gear and the first coupling element wherein the recess in not fully filled.

This results in an optimal contact between the side walls of the teeth of the fixation element and the teeth of the other two elements.

In an embodiment, the fixation element is made out of a flexible material, such a soft plastic or a rubber. Preferably, the whole fixation element is made of a flexible material so that the teeth will be flexible as well. Such flexible teeth further minimize any possible play between the elements and will further decrease backlash of the handle bar.

In an embodiment, the fixation element, the shaft gear and the first coupling element comprises an equal number of teeth.

In an embodiment, the assemble comprises a ring shaped actuator rotatable arranged within the handle bar coupling element and configured to, when being rotated, push the fixation element in the first axial direction away from the handle bar coupling element to enable rotation of the handle bar coupling element (8) relative to the shaft gear.

In an embodiment, the shaft at an outer surface comprises axially orientated ribs or grooves, the shaft gear comprising ribs arranged around a central opening for interaction with the ribs or the grooves on the outer surface of the shaft. In this way the shaft gear can be mounted rotation free around the shaft. Using multiple grooves around the circumference of the shaft will result in the possible forces being distributed over the whole surface of the shaft.

In an embodiment, the joint assembly comprises a front wheel bar coupling element for coupling a front wheel bar to the shaft, a rear wheel bar coupling element for coupling a rear wheel bar to the shaft. The joint assembly may comprise a blocking mechanism for blocking a rotation movement of the front wheel bar coupling element relative to the rear wheel bar coupling element, the blocking mechanism comprising one or more resilient element arranged in the front wheel bar coupling element or the rear wheel bar coupling element. The resilient elements will function as energy absorbing blocks so that an angle between the front wheel bar and the rear wheel bar can slightly change, which will provide some more comfort to the baby in case of a bumpy road.

According to a further aspect of the invention, a transporting device for transporting a person and/or luggage is provided comprising one or more joint assemblies as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter. In the drawings,

Figure 1 schematically shows a side-view of a stroller according to an embodiment;

Figure 2 schematically shows an exploded view of the joint assembly according to an embodiment;

Figure 3 schematically shows a perspective view of the shaft gear according to an embodiment;

Figure 4 schematically shows a perspective view of the handle bar coupling element;

Figure 5 schematically shows another perspective view of the handle bar coupling element;

Figure 6 schematically shows a perspective view of the fixation element according to an embodiment;

Figure 7 schematically shows a perspective view of the ring shaped actuator according to an embodiment, and

Figure 8A and 8B which schematically show cross sections of the teeth of the fixation element in their disengaged and engaged configuration.

It should be noted that items which have the same reference numbers in different Figures, have the same structural features and the same functions, or are the same signals. Where the function and/or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 schematically shows a side-view of a stroller 100 according to an embodiment. The stroller 100 comprises a frame to which one or two front wheels 21 are coupled. The front wheels 21 are, for example, swivel wheels. At a back side of the stroller 100 two rear wheels 20 are coupled to the frame. The frame also comprises a handle bar 108, a rear wheel bar 109 and the front wheel bar 112. The handle bar 108 is configured to be operated by a user, for example, to push the stroller 100 in a forward direction.

The frame comprises a joint assembly 25 for coupling the above mentioned stroller components 108, 109, 112. In this example, the joint assembly 25 comprises a first coupling element 8, also referred to as handle bar coupling element 8 and a second and third coupling element, referred to as rear wheel bar coupling element 9 and front wheel bar coupling element 12. The handle bar coupling element 8 is connected to the handle bar 108. The rear wheel bar coupling element 9 is connected to the rear wheel bar 109 and the front wheel bar coupling element 12 is connected to the front wheel bar 112.

In this embodiment, the frame also comprises a seat couple element 114 which may be used to couple a seat for a child to the stroller frame or for coupling a crib to the stroller frame. All the mentioned coupling elements are joining at a pivot point 26. In Figure 1 it has been indicated by arrow 32 that a user may set the handle bar 108 in a particular orientation. Setting of the orientation of the handle bar 108 may be performed by manipulating a handle or button that is connected via a cable (not shown) to elements within the joint assembly 25. The orientation of the handlebar 108 can be changed stepwise due to a specific arrangement within the joint assembly 25 as will be explained below.

Figure 2 schematically shows an exploded view of the joint assembly 25 according to an embodiment. The joint assembly 25 comprises a cover 1, an intermediate ring 2, a ring 3, an end cap 4, a fixation element 5 and a shaft gear 6. The joint assembly 25 further comprises a ring shaped actuator 7, a handle bar coupling element and a rear wheel bar coupling element 9. The assembly also comprises a locking element 10, a front wheel bar coupling element 12, a shaft 13, an interface part 14, a lock key 15 and a bolt 16. A number of springs 17 are arranged between the end cap 4 and the fixation element 5, and an axial spring 18 is present between the locking element 10 and the front wheel bar coupling element 12. Connection bolts 19 are used to connect the bars 108, 109, 112 to the coupling elements 8, 9 and 12 respectively. A sliding ring 22 may be present between the handle bar coupling element 8 and the front wheel bar coupling element 9.

The components shown in Figure 2 can be assembled by first inserting the lock key 15 into a hole (not shown) in the shaft 13, then placing the subsequent elements on the shaft 13 and finally coupling the bolt 16 onto the lock key 15 by screwing the bolt 16 into a threaded hole of the lock key 15, wherein the lock key 15 is restricted in axial and radial movement to enable tightening of the bolt 16.

The three coupling elements 8, 9, 12 holding the three different bars, are locked radially into each other on the outer diameter and compressed axially onto the shaft 13 by the bolt 1, the ring 3 and the end cap 4 on one side and the interface part 14 and the lock key 15 with threaded hole on the other side. This provides a connection of the three different bars with rotational freedom only.

The interface part 14 is arranged to connect the seat couple element 114 (also referred to as seat adapter 114) to the frame of the stroller 100. The interface part 14 itself and front wheel bar coupling element 12 are fixed to the shaft 13 fitting to e.g. grooves in the shaft 13 to prevent rotational movement and the lock key 15 to prevent axial movement in one direction. Axial movement in the opposite direction is restricted by the front wheel bar coupling element 12 and connected parts ending with the bolt 1. The interface part 14 may provide an interface to the seat adapter 114 using e.g. a snap hook and several fittings to resist forces due to frontal impact on the stroller 100.

Figure 3 schematically shows a perspective view of the shaft gear 6 according to an embodiment. The shaft gear 6 comprises an annular body 60 on which a plurality of teeth 61 are arranged. The teeth 61 extend from the annular body 60 in a direction parallel to a main axis of the shaft gear 6 which, at least in use, is the same as the main axis of the shaft 13, see Figure 2. The teeth 61 are positioned at a circumference of the shaft gear 6. As can be seen from Figure 3, the shaft gear 6 has a central opening where a number of ribs 62 are arranged which alternate with a number of grooves 63. The ribs 62 and grooves extend in a co-axial direction. Due the presence of the ribs 62, the shaft gear 6 can be arranged on (i.e. around) the shaft in a rotation free manner.

Figure 4 schematically shows a perspective view of the handle bar coupling element 8. The handlebar coupling element 8 is arranged for rotatably coupling the handle bar 108 to the shaft 13. The handlebar coupling element 8 comprises a disc shaped part 81 and a connection part 82. The disc shaped part 81 comprises a central opening 84 for receiving the shaft gear 6. The disc shaped part 81 comprises a plurality of teeth 85 arranged in a ring at a circumference of the central opening 81 and, in the assembled state, extending in a co-axial direction parallel to the main axis of the shaft 13. In the assembled state, each one of the plurality of teeth 85 is aligned with an associated tooth 61 of the shaft gear 6, see also Figure 3. As can be seen from Figure 4, the disc shaped part 81 in fact comprises three main disc shaped compartments having three different diameters. The compartment with the largest diameter has an inner wall 86. A compartment with a middle diameter has an inner wall 87, and a smallest compartment has an inner wall. As can be seen from Figure 4, the inner wall 87 of the mid-sized compartment transitions into inner face sides of the teeth 85. As can be seen from Figure 4, two protrusions 88, 89 are arranged around part of a circumference of an opening in the handle bar coupling element 8, extending in the same co-axial direction as the teeth 85.

Figure 5 schematically shows another perspective view of the handle bar coupling element 8. The handlebar coupling element 8 at the side facing the rear wheel bar coupling element 9 comprises two ridges 90, each being arranged partly around the central opening and extending in a co-axial direction. In the assembled state, the ridges 90 will protrude through a central opening of the rear wheel bar coupling element 9, see Figure 2, to interact with the locking element 10.

Figure 6 schematically shows a perspective view of the fixation element 5 according to an embodiment. The fixation element 5 comprises an annular body 50 having a central hole 51 so that the fixation element 5 can be arranged on the shaft 13. The fixation element 5 comprises a plurality of teeth 52 arranged in a ring and extending in a co-axial direction parallel to the main axis of the shaft 13. Each of the plurality of teeth 52 of the fixation element 5 is arranged to enter a recess between aligned teeth of the shaft gear 6 and the handle bar coupling element 8. The fixation element 5 in an engaged state disables a rotation of the handlebar coupling element 8 relative to the shaft gear 6. The fixation element 5 further comprises two protrusions 53 which will extend through holes of the shaft gear 6 and are arranged to interact with protrusions 88, 89 on the handle bar coupling element 8 so that the teeth 52 of the fixation element 5 cannot engage the teeth 61, 85 of the shaft gear 6 and the handle bar coupling element 8 in certain radial positions where the elevated areas 88 prevent this.

Figure 7 schematically shows a perspective view of the ring shaped actuator 7 according to an embodiment. The actuator 7 comprises a substantially ring shaped body 70 having three recesses 71 at a side facing the handle bar coupling element 8.

In this embodiment, the shaft gear 6 fits the shape e.g. grooves of the shaft 13 preventing it from radial movement with respect to the interface part 14. Handle bar coupling element 8 can rotate around the shaft gear 6 and a base surface of the teeth of these two elements (i.e. 6 and 8) is roughly in the same plane.

The fixation element 5 has a degree of axial freedom of movement and is positioned opposite and with the teeth facing the teeth of the handle bar coupling element 8 and the shaft gear 6. During certain radial positions of handle bar coupling element 8 with respect to shaft gear 6, the teeth of both parts align allowing the teeth of the fixation element 5 to be pushed into the cavities between the teeth of handle bar coupling element 8 and the shaft gear 6 by the springs 17. This interlocking of the teeth of all three parts prevents rotational freedom between the handle bar coupling element 8 and the shaft gear 6 and therefore between handle bar coupling element 8 and the front wheel bar coupling element 12 and the interface part 14.

Pulling a cable in the handle bar tube attached to the ring shaped actuator 7 causes it to rotate thereby pushing fixation element 5 outward using slanted surfaces (ramps or slides) causing the teeth to disengage and enabling rotational movement between the handle bar coupling element 8 and the front wheel bar coupling element 12 plus the interface part 14.

The angular size and the amount of the locking steps are dependent on the size of the teeth needed for desired strength in combination with the size of the complete coupling. A larger coupling results in more teeth and therefore more steps of a smaller angle. In principle, this system makes a play less, stepwise adjustment around 360 degrees possible. In an embodiment the amount of lock orientations is limited to 3 handlebar height steps with 9 degrees in between followed by a 120 degrees free folding, then one step fold-lock and a final end-stop position. For this reason the axial movement into the locking position of the fixation element 5 is only possible if the protrusions 53 on it fall in the corresponding deeper parts of the coupling element 8. When the handle bar coupling element 8 is rotated, elevations 88, 89 in the handle bar coupling element 8 support the protrusions 53 of the fixation element 5 so that the fixation element 5 cannot engage the teeth of coupling element 8. By varying the amount and/ or positions of these elevations 88 in relation to the protrusions 53 certain desired areas of unlocked free rotation on the 360 degree circle can be achieved.

In an embodiment the teeth of the shaft gear 6, of the handle bar coupling element 8 and of the fixation element 5 have slanted side walls. An orientation of the slanted side walls may be the same for teeth of all three elements 5, 6 and 8. The slanted walls will facilitate the entering of the teeth 52 of the fixation element 5 into the recesses between the teeth 61, 85 of the shaft gear 6 and the handle bar coupling element 8.

To better explain the advantages of the interacting teeth, an explanation is given below with reference to Figure 8A and 8B which schematically show cross sections of some of the teeth in their disengaged and engaged configuration. Figure 8A schematically shows some of the teeth 85 provided inside disc shaped part 81 of the handle bar coupling element 8. The teeth 61, 85 extend in a co-axial direction parallel to the main axis of the shaft 13, see also Figure 2. As can be seen from Figure 8A, in this example, the teeth 61, 85, 52 are tapered and symmetrical with respect to a plane of symmetry, see 802. In use, the main axis of the shaft 13 lies in this plane of symmetry 802. Each of the first, second and third plurality teeth 61, 85, 52 has two opposing side walls which are flat and tilted towards each other. AS such the teeth are trapezoidal or substantially trapezoidal. In a preferred embodiment, the degree of tilt of the opposing side walls is the same for teeth of both the first, second and third plurality of teeth. This will result in an optimal contact in the engaged (i.e. locked) state.

In a locked state, the handle bar coupling element 8 has a fixed orientation with respect to the front wheel bar coupling element 12. In the embodiment of Figure 2, the assembly 25 comprises rubber suspension blocks 11. In use, the rear wheel bar coupling element 9 is in contact with the front wheel bar coupling element 12 over the suspension blocks 11 but has (at least some) rotational freedom. The suspension blocks 11 together with this rotational freedom of the rear wheel bar coupling element 12, and thus of the rear wheel bar 109, will improve the overall comfort for the child in the stroller.

The handle bar coupling element 8 is arranged rotatable around the shaft gear 6. The handle bar coupling element 8 and the shaft gear 6 have at one side surface teeth that face towards the fixation element 5. The fixation element 5 has a surface with teeth 52 that face towards the teeth of elements 6 and 8.

The teeth of the fixation element 5 are moveable in a co-axial direction. When fixation element 5 is moved towards the handle bar coupling element 8, the teeth of the fixation element 5 engage with the teeth of both elements 6 and 8; this is shown in Figure 8B. In this way, the orientation of handle bar coupling element 8 is fixed with respect to the shaft gear 6, and, thus of the rear wheel bar coupling element 12.

When the fixation element 5 is moved away from the handle bar coupling element 8, the teeth of the fixation element 5 disengage with the teeth of both elements 6 and 8, see Figure 8A. In the disengaged state, the handle bar coupling element 8 may rotate with respect to the fixation element 6, see arrow 800 in Figure 8A, and thus with respect to the front wheel coupling element 12. This allows the adjustment of the orientation of the handle bar 8 with respect to the front wheel bar 112.

In an embodiment, the recesses between the teeth 61, 85 of the respective shaft gear 6 and the handle bar coupling element 8 are design such that, when they engage with the teeth 52 of the fixation element 5, the teeth 52 cannot completely insert into the recesses between the teeth 61, 85. Due to the slanted side wall and the fact that the teeth 52 will not completely insert the recesses, a good contact between their respective teeth/space interfaces is achieved. This prevents that in the fully engaged state, the handle bar coupling element 8 has still some play with respect to the shaft gear 6 (and, thus the front wheel bar 112).

As was mentioned above, the handlebar coupling element 8 may have a ring of teeth 85 with slanted sides that correspond to a ring of teeth 61 with slanted sides in the shaft gear 6. The shaft gear 6 may be press fitted with ribs to the shaft 13 also comprising ribs, to achieve a play free connection in rotational direction.

In an embodiment, the fixation element 5 is made out of a flexible material, or at least comprises teeth that are made of a flexible material. The flexible material may be a soft plastic or a rubber, or any other type of flexible material suitable. The flexibility in the fixation element 5 and/or the individual teeth 52 will compensate for teeth production tolerances causing all teeth to participate in resisting load. The angular surfaces of the teeth, optionally in combination with a slight width difference of the opposing teeth, will cause play to be pushed out.

The fixation element 5 may be actuated in the axial direction by one or more springs resting on the end cap 4 and countered by the ring shaped actuator 7 operated by pulling a cable from the handlebar 8 that causes the ring shaped actuator 7 to rotate. A rotating movement of the ring shaped actuator 7 is transformed by ramps in recesses 71 of the ring shaped actuator 7 into an axial movement pushing the fixation element teeth 52 out of the handlebar coupling element teeth 85 and the shaft gear teeth 61.

In certain orientations the handlebar 108 is restricted from locking by a combination of protrusions and slots of the fixation element 5 and the handle bar coupling element 8. This prevents the handlebar 108 from locking when folding the stroller 100. The fixation element 5 can only move into the locking position when the protrusions 53 on the fixation element 5 fall into corresponding slots in the handlebar coupling element 8.

In the embodiment of Figure 2, there is provided an end stop for the handlebar coupling element 8 in most forward orientation with respect to the front wheel bar coupling element 12. In the most forward folded orientation of the handlebar 108 there may be an end stop to prevent the handlebar 108 from rotating more than a designated folding angle when the fixation element 5 is not in its engaged state, i.e. the handlebar buttons are pulled backwards.

Also an end stop for the handlebar coupling element 8 in a most rearward orientation with respect to the front wheel bar coupling element 12 may be provided. In the most rearward handlebar orientation there may be an end stop to prevent the handlebar 108 from rotation further down than the lowest handlebar pushing orientation when the fixation element 5 is not in its engaged state, i.e. handlebar buttons pulled backwards.

In the embodiment shown in Figure 2, the rear wheel coupling element 9 can be locked and unlocked to the front wheel coupling element 12, which locking and unlocking is actuated by handlebar coupling element 8 position. For that purpose, the locking element 10 is fitted on the shaft 13 providing a block for a protrusion on the rear wheel coupling element 9, preventing radial movement of the rear wheel coupling element 9 with respect to the front wheel coupling element 12. When the handlebar 108 is folded forward, the handlebar coupling element 8 rotates thereby causing a slanted protrusion on the handlebar coupling element 8 to push the locking element 10 outward against a spring force, provided by the axial spring 18. This provides freedom for the rear wheel coupling element 9 to rotate and enable folding forward of the rear wheel bar 109.

When the handlebar 108 is returned to the unfolded orientation the locking element 10 will become free to return to its locking position in the rear wheel coupling element 9 under influence of the spring.

In an embodiment, the joint assembly 25 comprises a blocking mechanism for blocking a rotation movement of the front wheel bar coupling element 12 relative to the rear wheel bar coupling element 9. The blocking mechanism may comprise one or more resilient elements arranged in the front wheel bar coupling element 12 or the rear wheel bar coupling element 9. In Figure 2, an embodiment is shown wherein two rubber elements 11 are arranged. The rubber element 11 are fitted between opposite protrusions on the rear wheel coupling element 9 (not visible in Figure 2) and the front wheel bar coupling element 12. These rubber elements 11 can be compressed slightly, allowing for movement when the front wheel bar coupling element 12 and the rear wheel bar coupling element 9 are rotated in opposite direction as a result of loads being applied to the wheels 20, 21. In addition to this elastic suspension effect, the rubber also serves to absorb part of the energy induced in the system applying dynamic loads to the wheels 20, 21.

In the embodiment of Figure 2, there is provided a resistance lock between the rear wheel bar coupling element 9 and the front wheel bar coupling element 12 in most forward (folded) orientation. In the most forward, folded orientation the rear wheel bar 109 stays folded because it is held by a resistance lock in the joint assembly 25. This resistance lock is formed by two protrusions, one on the locking element 10 and one on the rear wheel bar coupling element 9 (not visible in Figure 2). The protrusions are pushed together by the spring axial spring 18 on the locking element 10 and can be pushed apart against the spring force when a force is applied to the rear suspension assembly.

As was mentioned above, pushing a flexible fixation element 5 with a ring of slightly wider teeth, also with slanted sides, into the aligned teeth of the shaft gear 6 and the handlebar coupling element 8 causes a lock between these two parts. The ring of teeth 52 on the fixation element 5 may be twice as wide as the rings of teeth on the shaft gear 8 and on the handlebar coupling element 8. However, the widths of the three rings of teeth may have other relative widths. The width of the ring of teeth 52 do not need to be equal to the total of the width of the engaging rings. As long as the teeth 52 engage at least part of both the teeth of the shaft gear 8 and the teeth of the handle bar coupling element 8, the locking fixation of the rotation movement will occur.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments. Instead of hollow bars, solid bars could be used which would make the frame more solid, but more heavy. Furthermore, instead of a transporting device for a person, a device for transporting luggage may comprise the described joint assembly.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

A hinge assembly comprises: - a shaft (13); - a gear (6) arranged on the shaft in a non-rotatable manner, wherein the gear comprises a first plurality of teeth arranged in a first ring on a circumference of the gear and extending in a first coaxial direction parallel to a main axis of the axis (13); - a first coupling element (8) adapted for rotatably coupling a first rod (108) on the shaft (13), the first coupling element (8) comprising a substantially disc-shaped part and an elongated connecting part for receiving the first rod, the substantially disc-shaped part comprising a central aperture for receiving the gear (6) and comprising a second plurality of teeth (85) arranged in a second ring concentric to the central aperture and extending in the first coaxial direction wherein each of the second plurality of teeth (85) is aligned with an associated tooth of the first plurality of teeth (61) of the gear (6), - a securing element (5) arranged on the shaft (13) and comprising a third plurality of teeth (52) disposed in a third ring and extending in a second coaxial direction parallel to the major axis of the shaft (13), but reversed to the first coaxial direction, where Each of the third plurality of teeth is adapted to penetrate a recess between the teeth of the first and second plurality of teeth so that the securing element (5) in a coupled state rotates the first coupling element (8) relative to makes the gear (6) impossible.

The hinge assembly of claim 1, wherein each of the first, second, and third plurality of teeth is tapered and symmetrical with respect to a plane of symmetry, wherein the major axis of the shaft (13), at least in use, lies in the plane of symmetry.

The hinge assembly of claim 2, wherein each of the first, second, and third plurality of teeth has two opposite side walls that are flat and tilted toward each other.

The hinge assembly of claim 3, wherein the degree of tilt of the opposite side walls is the same for the teeth of both the first, second and third plurality of teeth.

The hinge assembly of claim 4, wherein in the coupled state each of the third plurality of teeth is forced into a recess between two adjacent teeth of the first and second plurality of teeth, with both side walls of each of the third plurality of teeth contacting with a respective side wall of the two adjacent teeth, wherein the recess is not completely filled.

A hinge assembly according to any one of the preceding claims, wherein the securing element (5) is made of a flexible material.

A hinge assembly according to any one of the preceding claims, wherein the locking element (5), the gear (6) and the first coupling element (8) have an equal number of teeth.

A hinge assembly according to any one of the preceding claims, wherein the assembly comprises an annular actuator (7) rotatably arranged within the first coupling element (8) and configured to rotate the locking element (5) in the first axial direction when rotated. to push away from the first coupling element (8), to allow rotation of the first coupling element (8) relative to the gear wheel (6).

A hinge assembly according to any one of the preceding claims, wherein the shaft (13) comprises axially oriented ribs or grooves on an outer surface, and wherein the gear (6) comprises ribs arranged on an inner surface of a central opening of the gear (6) for interaction with the ribs or grooves on the outer surface of the shaft (3).

A hinge assembly according to any one of the preceding claims, further comprising: - a second coupling element (12) for coupling a second rod to the axle, - a third coupling element (9) for coupling a rear wheel rod to the axle.

A hinge assembly according to claim 10, wherein the hinge assembly comprises a blocking mechanism for blocking a rotational movement of the second coupling element (12) relative to the third coupling element (9), the blocking mechanism comprising one or more resilient elements arranged in the second coupling element (12) or the third coupling element (9).

A transport device for transporting a person and / or luggage, the transport device comprising one or more hinge assemblies according to one of the preceding claims.

A transport device according to the preceding claim, wherein the transport device is a pram or a buggy for transporting a baby or child.