WO1994009999A1 - Wheel/suspension assembly - Google Patents

Abstract

An assembly comprising a wheel (2) and a related suspension member (1) for attachment to a vehicle chassis. The suspension member comprises first (3) and second (4) arms provided with a respective joining element (8) located on the rotational axis of the wheel for interconnecting said arms in a concealed manner. When interconnected, said first and second arms define a first opening for the wheel, which is supported and guided within the space defined by the arms by means of bearings (15, 16) coaxial with said axis.

Description

 "Assembly comprising a wheel and a suspension member"

The invention relates to an assembly comprising a wheel and a suspension member for this wheel, said suspension member being designed to be fixed to the chassis of a means of transport.

Such assemblies are generally known. They are for example used for carts em¬ employed in self-service stores, airports or railway stations, wheelbarrows or other means of transporting goods generally. The wheel is, in general, connected to the suspension member via its axle, which is fixed with a screw to the suspension member. This fixing means is simple and inexpensive and allows rapid replacement of the wheel.

A disadvantage of the known assemblies is that, when they are used for means of transport, made available to the public, such as the aforementioned carts, their easy disassembly makes them vulnerable to theft or other acts of vandalism. In addition, it suffices to disassemble a single wheel to make the trolley unusable.

The object of the present invention is to produce an assembly which is substantially less vulnerable to theft and other acts of vandalism.

To this end, an assembly according to the invention is characterized in that said suspension member comprises a first and a second arm which are each provided with a connecting element disposed at the height of the axis of rotation of the wheel and intended to link between them said arms concealedly, said first and second arms forming, when they are connected, a first opening allowing the passage of the wheel which is supported and guided inside the space enveloped by the arms at l using rolling means arranged coaxially to said axis. The wheel turns through said opening and, as it is supported and guided inside the space enveloped by the arms, it is necessary to open the arms in order to be able to remove the wheel. However, because the first and second arms are connected to each other in a concealed manner, it is practically impossible to see the connecting elements from the outside. The dissociation of the two arms therefore becomes impossible without completely destroying the whole. Also the one who wants to steal a wheel, is therefore obliged to destroy the whole, which makes the theft less easy. In addition, since the arms are connected together and partially envelop the wheel, a relatively rigid structure is obtained, which makes it less vulnerable to acts of vandalism. A first preferred embodiment of an assembly according to the invention is characterized in that said rolling means are formed by a track of balls disposed between a support formed on the inner flank of each arm and a profile arranged in each side of the rim of the wheel. This allows a good distribution of the forces on the wheels and is simple to assemble. In addition, such a path of balls makes it possible to substantially limit the imprint on the inner flank of the arm. A second preferred embodiment of an assembly according to the invention is characterized in that said first and second arms form, when they are connected, a second opening which is substantially perpendicular to said axis intended to house a junction pin for fixing the assembly to said chassis. The attachment of the assembly to the chassis of the means transport can thus be performed without the junction axis being apparent. This prevents the assembly from being easily removed from the chassis, making theft more difficult. A third preferred embodiment of an assembly according to the invention is characterized in that a stop is housed in a first cavity situated at a fixing end of the assembly of the means of transport, said stop being arranged coaxial with the junction axis. The stop can thus absorb the load force exerted by the objects loaded in the carriage, in particular the axial forces exerted vertically on the assembly.

A fourth preferred embodiment of an assembly according to the invention is characterized in that a ball bearing is housed in a recess situated coaxially with respect to the second opening and disposed inside the space enveloped by the arms. This ball bearing can thus absorb the transverse torque exerted on the assembly by the objects loaded in the carriage. In addition, it ensures the rigidity of the whole.

Preferably, a circlip is housed in another recess situated coaxially with respect to the second opening and disposed inside the space enveloped by the arms. The assembly of the assembly on the trolley can thus be carried out easily and in a durable manner.

Preferably, a mark is applied in the outer face of the arms. This allows the maintenance service, in case of replacement of an assembly, to easily find the place to apply a tool suitable for dismantling.

A fifth preferred embodiment of an assembly according to the invention is car.jctor îsé in that the first and second arms comprise a tubular recess arranged coaxially with respect to the junction axis, a ring being housed in said tubular recess. This allows a reliable and not very vulnerable assembly of the assembly. The invention will now be described in more detail using the drawings which illustrate an embodiment of an assembly according to the invention. In the drawings:

FIG. 1 illustrates an example of an assembly according to the invention.

FIGS. 2 and 3 schematically illustrate a part of the first, respectively of the second, arm of an assembly according to the invention.

Figure 4 shows a cross-sectional view of an assembly according to the invention.

Figure 5 respectively 6 illustrates a second respectively a third embodiment of an assembly according to the invention.

FIG. 7 illustrates another embodiment of an assembly according to the invention.

In the drawings, the same reference has been assigned to the same element or to an analogous element.

An exemplary embodiment of an assembly according to the invention is illustrated in FIG. The assembly comprises a suspension member 1 to which a wheel 2 is suspended. The assembly is preferably made of a synthetic material, for example SMC. However, other materials, such as for example metal or a combination of metal and synthetic material, can also be used. The assembly is preferably used for trolleys, in particular trolleys intended for the use of self-service stores, airports or stations. Other applica¬ tions, such as for example toys, hospital beds or wheelbarrows, are also envisaged. The wheel is preferably provided with a profile when it is entirely made of synthetic material. tick, or when covered with a rubber or plastic strip.

The suspension member 1 comprises a first 3 and a second 4 arms, which are concealed between them. The member 1 also includes a cover 5 placed on the first and second arms. The cover 5 protects the interior of the arms against dust 8. The junction pin passes through the cover

5 and is used to fix the assembly to the chassis of a means of transport, such as the above-mentioned carriage. The junction pin is preferably provided with a thread 26, as illustrated in FIG. 4, making it possible to screw the pin

6 in the chassis. Other connecting means, such as for example bonding, are also possible for connecting the connecting axis to the chassis. According to another alternative, the junction pin 6 is not part of the assembly, but is integrated into the chassis, for example by molding or welding.

Figure 2, respectively 3, schematically illustrates part of the first 3, respectively second 4, arm. The first arm 3 is provided with a first connecting element 7, for example a female element formed by a nozzle 7, arranged projecting relative to the side of the arm. The second arm 4 is provided with a second connecting element 8, for example a male element, formed by a rod 8 arranged projecting relative to the side of the arm. The rod 8 fits into the nozzle 7. The connection between the first and the second arm is therefore carried out concealed inside the suspension member, as illustrated in FIG. 4.

The advantage of this solution will be exp..que below.

If necessary, the rod 8 can also be glued to the inside of the nozzle 7 in order to connect the arms together in a non-removable manner. Other embodiments of the connecting elements are also envisaged. bles, such as the use of a safety pin, a bayonet socket or by clipping.

When the first 3 and the second 4 arms are connected together, they form a first opening 10 allowing the passage of the wheel 2. The wheel is arranged so as to be able to rotate around an axis 9. The wheel is however completely hollow up to the axis 9 where the connecting elements 7 and 8 are housed. The rim of the wheel 2 is supported and guided within the space delimited by the arms, using rolling means 15 and 16 arranged coaxially to the axis 9.

In the embodiment illustrated in FIG. 4, the rolling means are formed by two circular ball paths 15, 16 arranged on either side of a central axis 17. The balls of the ball path are housed between a support 18 formed on the inner flank of the arm and a profile 19 formed in each face of the rim of the wheel 2. The balls are made of metal or acetal resin. During its rotation, the wheel therefore rotates on the ball tracks which rest on the support 18 of the arms. When the assembly is mounted on a carriage, most of the effort is carried on the lower rolling means 13, 14. The size of the balls, arms and wheel is chosen so that the weight is supported by six marbles, three on each side. This makes it possible to better distribute the weight over the balls and therefore to limit the imprint of the balls on the support 18. Instead of using a track of balls, it is also possible to use bearings. According to another alternative, the rolling means are arranged on the nozzle 7 but always coaxially with the axis 9. The balls or the bearings are preferably made of synthetic material. However, steel balls or nylon bearings can also be used.

As illustrated in Figure 4, the connecting elements 7,8 and the rolling means 15, 16, are not accessible from the outside when the assembly, according to the invention, is mounted. The rolling means are completely embedded inside the space enveloped by the arms. In addition, the connecting elements 7,8 are rigidly connected to each other and their connection is concealed. The wheel cannot therefore be dissociated from the assembly without destroying the arms 3 and 4, which considerably annoys those who would like to appropriate the wheel. In addition, the wheel being hollow up to the axis 9, its use for other purposes is greatly limited.

The set is preferably made of a rigid synthetic material, which makes it significantly less vulnerable to acts of vandalism. The fact that the balls 15 and 16 are not accessible from the outside also considerably limits vandalism.

FIG. 5 illustrates a second embodiment of an assembly according to the invention. This embodiment facilitates the mounting of the various components of the assembly. This embodiment is distinguished by the fact that the arms 3 and 4 have in their upper part 30, that is to say the part which is located between the chassis of the means of transport and the wheel itself, a tubular recess 31 . This tubular recess is coaxial with respect to the median axis 17 and extends over at least 2/3 of the height of this upper part.

When the assembly is assembled, a substantially tubular ring 32 is housed in the tubular recess 31. After having inserted a circlip 21 or a claw washer in the recess 22 and joined the arms 3 and 4 as well as the wheel 2 and the ball tracks 15 and 16, the ring 32 is introduced into the tubular recess 31. The ring thus joins the two arms. The ring being immersed in one tubular recess is not easily removable, which makes it less vulnerable to acts of vandalism. In addition, it ensures coaxiality during the mounting of the arms and improves the mechanical connection of the various components.

The ring is preferably also made of rigid synthetic material. If necessary, the ring can, after assembly, be glued into one recess 31 in order to make its disassembly impossible without destroying the assembly.

FIG. 6 illustrates a third embodiment of an assembly according to the invention also making it possible to facilitate the mounting of the various components of the assembly. This embodiment is distinguished by the fact that the first arm 3 is provided with first bosses 35 and first cavities 33 while the second arm 4 has second bosses 34 and second cavities 36. In the example illustrated, there each time two bosses and two cavities, but it goes without saying that this is an example and that other variants with more or less bosses and cavities are also possible. The first bosses 34 and cavities 33 are arranged in such a way that, when the first and second arms are assembled, the first bosses are housed in the second cavities. The same goes for the second bosses 34 and the first cavities 33.

The first respectively second bosses are pierced with a perforation 39 respectively 40. The material located between the cavities 33 respective¬ ment 36 is also provided with a perforation s _ killed in the respective bosses and that in. iJ te matter are aligned along the same axis. When the arms 3 and 4 are assembled, the respective bosses are therefore housed in their respective cavities. When the two arms are joined, a dowel 37 respectively 38 is introduced into the perforations 40 respectively 39. Thanks to these chevil¬, the arms are joined reliably. The ankles being immersed in the perforations, it is practically impossible to remove them, which makes this assembly can be vulnerable to acts of vandalism. Preferably, the ankles are made of frosted pultruded rushes. The use of frosted pultruded rods has the advantage of forming a very reliable and non-removable connection. Indeed, the pultruded rods have a very high coefficient of friction, which makes their disassembly very difficult.

The assembly of the assembly on a chassis of a means of transport, such as a trolley, is carried out using the junction pin 6, which is housed in a second opening 20 arranged substantially perpendicularly to axis 9. This second opening is preferably slightly conical and its diameter is reduced starting from the lower end.

The junction pin 6 has, at its lower end, a circular recess 22 in which is housed the circlip 21, itself housed in another recess of the first and second arms. Instead of using a circlip, it is also possible to use a claw washer, which allows the use of axes of larger diameters. The circlip is preferably located at a certain distance from the first opening 10, near the bottom of the upper part of the arm. Thus the circlip does not interfere with the assembly of the assembly on the chassis.

A ball stop 23 is housed in a cavity located just below the cover 5. This ball stop serves to collect the load forces exerted vertically on the assembly when the trolley or other means of transport is loaded.

The rotation of the assembly around the median axis 17 is essentially ensured by the stop 23 assisted by the bearing 24, housed in a recess of the arms situated approximately between the ball stop 23 and the circlip 21. The bearing 24, which is preferably a ball bearing, is also intended to collect the transverse forces exerted on the assembly in the event of an impact of the carriage, for example against an edge. The bearing 24 also prevents excessive torque being exerted on the assembly.

Preferably, the end of the junction pin 6, intended to be housed in the opening 10, is slightly conical, which facilitates the mounting of this pin 6 in the second opening. Indeed, the conical tip of the axis will cause the circlips 21 or the claw washer to move apart when it is inserted into the second opening 20. When the circular recess 22 has reached the level of the circlips, the latter will come automatically fit into the recess 22, securing the assembly to the chassis while allowing rotation of the assembly relative to the axis 17. The assembly of the assembly is for example made from the first arm 3 into which are introduced the ball bearing 24 as well as the cir¬ clips or the claw washer. These elements are mounted in their respective cavity provided in the arm. The balls of a first ball path are also arranged in the support. Thus, for example, when we first take the first arm 3, the balls 15 are arranged on the support 18. Then, the wheel 2 is slid over the rod 7 to come to bear on the balls 15. A second track of balls is then placed on the wheel. The second arm 4 is then connected to the first arm 3 using the connecting elements 7 and 8 which, preferably, are glued together. With regard to the embodiments comprising a ring 32 (FIG. 5) or dowels 37, 38 (FIG. 6), the ring or the dowels are mounted after joining the two arms and the wheel. The ball bearing 23 is then introduced into the cavity provided for this purpose. The junction pin 6 is then introduced into the second opening 20 and fixed in the circlip or in the washer. Finally, the cover 5 is fixed to the assembly, which is then ready to be mounted on a chassis.

Preferably, a small mark 25 is provided on the outer face of at least one of the arms 3 or 4. The mark 25 is situated approximately between the bearing 24 and the circlip 21 and is used for dismantling the assembly when the latter must be replaced for reasons of wear, for example. Indeed, since the assembly is difficult to dismantle for reasons of theft and vandalism, special provisions must be made for the replacement of worn parts. The reference 25 thus gives an indication for applying a drill there and drilling a hole through the arms and the axis 6. After the hole has been drilled, a bar is introduced therein to disassemble the entire chassis.

FIG. 7 illustrates another embodiment of the upper flange of an arm forming part of the assembly according to the invention. This embodiment differs from that shown in Figure 4 because instead of a ball bearing 23 and a bearing 24, it includes a combined bearing. This combined bearing comprises a guide 41 forming an outer body of the bearing and whose shape resembles that of a stair step. The guide is mounted at the level of the end of attachment of the assembly to the chassis of the carriage, coaxially with respect to axis 6. Preferably, this guide is self-lubricating, which ensures good rotation of the assembly relative to the axis 6. The guide is for example made of a fatty plastic material. In its lower part, this guide extends substantially parallel to the axis 6 and is juxtaposed with the axis, which allows the axis 6 to be guided by this guide. In addition, the guide being located at a certain depth in the assembly makes it possible to collect relatively high torques which could be exerted on the wheel. An intermediate piece 42 also forming part of the combined bearing is mounted between the guide and a cover 44. The intermediate piece 42 is supported on the guide 41 by means of another track of balls 43, which allows better cashing the forces exerted transversely on the assembly when the carriage is loaded.

The guide and the intermediate part allow tent not only to guide the axis 6 during assembly, but also to distribute the force on two separate parts. In addition, compared to the embodiment illustrated in Figure 4, there is only one bearing to mount, which facilitates assembly and reduces the manufacturing cost.

Claims

1. Assembly comprising a wheel and a suspension member for this wheel, said suspension member being arranged to be fixed to the assembly to the chassis of a means of transport, characterized in that said suspension member comprises first and second arms which are each provided with a connecting element arranged at the height of the axis of rotation of the wheel and intended to interconnect said arms concealedly, said first and second arms forming, when they are connected, a first opening allowing the passage of the wheel which is supported and guided within the space enveloped by the arms using rolling means arranged coaxially with said axis. 2. Assembly according to claim 1, characterized in that said rolling means are formed by a track of balls arranged between a support formed on the inner flank of each arm and a profile arranged in each face of the rim of the wheel. 3. An assembly according to claim 1 or 2, characterized in that said first and second arms form, when connected, a second opening substantially perpendicular to said axis and intended to accommodate a junction axis allowing the assembly of said assembly frame. 4. An assembly according to claim 3, characterized in that a stop is housed in a first cavity located at a fixing end of the assembly by means of transport, said stop "ant arranged coaxially with the junction axis. 5. An assembly according to claim i or 4, characterized in that a bearing is housed in a recess located coaxially with respect to the second opening and disposed inside the space enveloped by the arms. 6. Assembly according to one of claims 3, 4 or 5, characterized in that a circlip is housed in another recess located coaxially with the second opening and arranged inside the space enveloped by the arms . 7. An assembly according to one of claims 3, 4 or 5, characterized in that a claw washer is housed in another recess located coaxially with respect to the second opening and disposed inside the space enveloped by the arms. 8. Assembly according to one of claims 1 to 6, characterized in that a reference is included in the outer face of the arms. 9. An assembly according to claim 3, characterized in that a combined bearing is housed in a first cavity located at an end for fixing the assembly to the transport means, said combined bearing being arranged coaxially with the junction axis and being composed by a guide and an intermediate piece. 10. An assembly according to one of claims 3 to 9, characterized in that the first and second arms have a tubular recess arranged coaxially with respect to the junction axis, a ring being housed in said tubular recess. 11. An assembly according to one of claims 3 to 9, characterized in that the first respecti¬ vely the second arm comprises first respective¬ second cavities and bosses arranged so that the first respectively second bosses are received in the second respectively first cavities during assembly of the arms, a pin each time being housed in a perforation which passes through said bosses and penetrates into the material of which said arm is made. 12. The assembly of claim 11, characterized in that the ankle is formed by a frosted pultruded rod. 13. Assembly according to one of claims 1 to 12, characterized in that it is made of synthetic material. 14. Combined bearing intended to be used in an assembly according to claim 9. 15. Trolley, in particular trolley for self-service store, equipped with an assembly according to one of claims 1 to 14.