WO2021174265A1

WO2021174265A1 - A castor wheel assembly

Info

Publication number: WO2021174265A1
Application number: PCT/ZA2021/050011
Authority: WO
Inventors: Jean-Patrick LEGER
Original assignee: Leger Jean Patrick
Priority date: 2020-02-26
Filing date: 2021-02-26
Publication date: 2021-09-02
Also published as: ZA202210468B

Abstract

A castor wheel assembly (10) which includes a mounting member (12) for in use, mounting the castor wheel assembly (10) to a load carrier, a wheel bracket (14) for rotatably keeping a wheel, and a friction reduction element (18) mountable in between the mounting member (12) and the wheel bracket (14) for facilitating swivelling of the wheel bracket (14) relative the mounting member (12), wherein the friction reduction element (18) is manufactured from a material having a coefficient of friction value less than that of the mounting member (12) and/or the wheel bracket (14).

Description

A CASTOR WHEEL ASSEMBLY

Technical field of the invention

This invention relates to a castor wheel assembly.

Background to the invention

Castor wheel assemblies which include a ball or roller bearing arrangement located between moving parts of the assembly are well known in the art.

Castor wheel assemblies of the kind typically includes a mounting member for mounting the assembly to a basket, trolley frame, or the like, and a wheel bracket for keeping a wheel, wherein swivelling of the wheel bracket relative the mounting member is facilitated by the ball, or, roller bearing arrangement.

One of the problems associated with castor wheel assemblies of the kind is that even when including a seal is that due to its configuration dirt, water and moisture often enters the ball or roller bearing arrangement resulting in wear, friction and/or corrosion which inhibits swivelling of the wheel attachment member, and thereby steering of the vehicle.

Another disadvantage of the current design is the inclusion of a pair of flat plates wherein each plate has a groove defined therein for guiding the balls or rollers, and, to hold in place the bearing arrangement.

In use, the pair of grooves will define an upper and lower load bearing surface against which the ball or roller bearings will abut and bear during use. The metal used is often a relatively soft metallic material, such as mild steel, and any excessive upward force or impact exerted on the castor wheel assembly often dent the grooves and/or balls or rollers, thereby hinders the smooth roller action of the balls or rollers relative to the grooves. The applicant having considered the above proposes the invention described hereunder.

Summary of the invention

According to a first aspect of the invention there is provided a castor wheel assembly which includes: a mounting member for in use, mounting the castor wheel assembly to a load carrier; a wheel bracket for rotatably keeping a wheel; and a friction reduction element mountable in between the mounting member and the wheel bracket for facilitating swivelling of the wheel bracket relative the mounting member; wherein the friction reduction element is manufactured from a material having a coefficient of friction value less than that of the mounting member and/or the wheel bracket.

The load carrier may take the form of a trolley frame, receptacle, basket, or the like.

The friction reduction element may be annular shaped.

The friction reduction element may take the form of a washer type element.

The friction reduction element may have a coefficient of friction value of less than about 0.3 when employing the formula as set out in document ASTM D3702 - 94(2019) entitled “Standard Test Method for Wear Rate and Coefficient of Friction of Materials in Self- Lubricated Rubbing Contact Using a Thrust Washer Testing Machine”.

The mounting member may include a receiving formation for complementarily receiving the friction reduction element. The wheel bracket may include a receiving formation for complementarily receiving the friction reduction element.

The receiving formation may take the form of recess.

In another form of the invention the friction reduction element may include a securing formation for securing the friction reduction element relative the mounting member and/or the wheel bracket.

The securing formation may take the form of a flange defined circumferentially about and extending upward and away from the friction reduction element.

The flange may have a diameter less than that of the friction reduction element.

The securing formation may take the form of an annular shaped formation having a flat upper surface.

The annular shaped formation may have a diameter less than that of the friction reduction element.

In a preferred embodiment of the invention the mounting member may include a receiving formation for complementarily receiving the securing formation for in use, keeping the friction reduction element in place.

The receiving formation may also be defined about an upper facing surface of the wheel bracket for complementarily receiving the securing formation for in use, keeping the friction reduction element in place.

The receiving formation may include a recess and further having a stepped configuration for receiving the securing formation.

The wheel bracket may include a seating formation defined an upper facing surface thereof for in use, seating the friction reduction element. The castor wheel assembly may further include an interconnector for operatively interconnecting the mounting member, friction reduction element, and, wheel bracket.

The interconnector may include a bolt and nut arrangement.

The interconnector may include a bushing type element for in use, to promote swivelling of the wheel bracket relative the mounting member.

According to a second aspect of the invention there is provided a friction reduction element for in use, allows swivelling of a wheel bracket member relative a mounting member of a castor wheel assembly, the friction reduction element further having a coefficient of friction value less than that of the wheel bracket member and/or mounting member.

The friction reduction element may be annular shaped.

The friction reduction element may take the form of a washer type element.

The mounting member may include a receiving formation for complementarily receiving the friction reduction element.

The wheel bracket may include a receiving formation for complementarily receiving the friction reduction element.

The receiving formation may take the form of recess. In another form of the invention the friction reduction element may include a securing formation for securing the friction reduction element relative the mounting member and/or the wheel bracket.

In a preferred form of the invention the mounting member may include a receiving formation for complementarily receiving the securing formation for in use, keeping the friction reduction element in place.

In another form of the invention the receiving formation may be defined about an upper facing surface of the wheel bracket for complementarily receiving the securing formation.

The receiving formation may take the form of a recess.

The wheel bracket may include a seating formation defined an upper facing surface thereof for in use, seating the friction reduction element.

The castor wheel assembly may further include an interconnector for operatively interconnecting the mounting member, friction reduction element, and, wheel bracket. The interconnector may include a bolt and nut arrangement.

The interconnector may include a bushing type element for in use, promoting swivelling of the wheel bracket relative the mounting member.

Brief Description of the Drawings

The invention will now be described by way of the following, non-limiting example with reference to the accompanying drawings.

In the drawings: -

Figure 1 is an exploded top of a castor wheel assembly,

Figure 2 is an exploded bottom view of the castor wheel assembly shown in figure 1 ;

Figure 3 is a top perspective view of the friction reduction element; and

Figure 4 is a side view of the friction reduction element shown in figure 3, in accordance with the invention.

Detailed description of the drawings

In the drawings, reference numeral 10 generally depicts a castor wheel assembly which includes a mounting member 12 for, in use, mounting the castor wheel assembly 10 to a load carrier, a wheel bracket 14 for rotatably keeping a wheel 16 and a friction reduction element 18 mountable in between the mounting member 12 and the wheel bracket 14 for facilitating swivelling of the wheel bracket 14 relative the mounting member 12, wherein the friction reduction element 18 is manufactured from a material having a coefficient of friction value less than that of the mounting member 12 and/or the wheel bracket 14, respectively. The load carrier can take the form of a trolley frame, receptacle, basket, or the like.

In the embodiment shown friction reduction element 18 is annular shaped.

It is however to be appreciated that friction reduction element 18 can take any suitable geometrical shape and size

Friction reduction element 18 will preferably have a coefficient of friction value of less than about 0.3 when employing the formula as set out in document ASTM D3702 - 94(2019) entitled “Standard Test Method for Wear Rate and Coefficient of Friction of Materials in Self-Lubricated Rubbing Contact Using a Thrust Washer Testing Machine”.

Abovementioned international standard was developed in accordance with internationally recognised principles on standardisation established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organisation Technical Barriers to Trade (TBT) Committee.

Friction reduction element 18 can take the form of a conventional washer type element (not shown) where a complementarily shaped recess will be defined about outward facing surfaces of the mounting member 12, or, wheel bracket 14, for keeping the washer type friction reduction element in place.

In a preferred embodiment of the invention the friction reduction element 18 includes a securing formation for securing the friction reduction element relative the mounting member.

In the embodiment shown, more clearly in figures 1, 3 and 4, the securing formation takes the form of an annular shaped formation 20 having a flat upper surface and a diameter less than that of the friction reduction element 18, the annular shaped formation 20 further arranged centrally the friction reduction element 18. The securing formation can also take the form of a flange defined circumferentially about and extending upward and away from the friction reduction element, the flange having a diameter less than that of the friction reduction element.

In the embodiment shown, see figure 2, mounting member 12 includes a receiving formation 22 which includes a recess and further having a stepped configuration for complementarily receiving the annular shaped securing formation 20 so as to when in assembled form, keep the friction reduction element 18 in place.

It is however to be appreciated that the receiving formation 22 can also be defined in the wheel bracket 14 for complementarily receiving the securing formation.

Figure 1 depicts seating formation 15 defined about an upper surface of wheel bracket 14 for seating of the friction reduction element 18 onto the wheel bracket 14, when in use.

It is however to be appreciated that wheel bracket 14 can also include the receiving formation 22 defined about an upper surface for complementarily receiving the friction reduction element 18.

Castor wheel assembly 10 will typically further include a suitable interconnector (not depicted) for operatively interconnecting the mounting member 12, friction reduction element 18, and, wheel bracket 14.

As such, the interconnector can include a bolt and nut arrangement or the like.

A bushing type element (not shown) can further be included for in use, promoting swivelling of the wheel bracket 14 relative the the mounting member 12. The Applicant considers the invention advantageous in that a friction reduction element is provided which can replace the conventional ball or roller bearing assembly used in conventional castor wheels. Although roller and ball bearing assemblies result in smoother and lower friction, compared to the friction reduction element, these types of assemblies are, due to its configuration, sensitive to impact forces and debris such as, dirt, water and moisture which negatively affects the functionality of the roller and ball bearing assembly, and thereby the castor wheel.

The inclusion of the friction reduction type element allows the castor wheel to operate in dirty and/or wet conditions and also have a greater resistance to impact, which altogether extends the operational life of the castor wheel, with or without the inclusion of any seal. It shall be understood that the examples are provided for illustrating the invention further and to assist a person skilled in the art with understanding the invention and are not meant to be construed as unduly limiting the reasonable scope of the invention.

Claims

1. A castor wheel assembly which includes: a mounting member for in use, mounting the castor wheel assembly to a load carrier; a wheel bracket for rotatably keeping a wheel; and a friction reduction element mountable in between the mounting member and the wheel bracket for facilitating swivelling of the wheel bracket relative the mounting member; wherein the friction reduction element is manufactured from a material having a coefficient of friction value less than that of the mounting member and/or the wheel bracket.

2. A castor wheel assembly as claimed in claim 1 wherein the friction reduction element is substantially annular shaped.

3. A castor wheel assembly as claimed in any one or more of the preceding claims wherein the friction reduction element takes the form of a washer type element.

4. A castor wheel assembly as claimed in any one or more of the preceding claims wherein the mounting member includes a receiving formation for complementarily receiving the friction reduction element.

5. A castor wheel assembly as claimed in any one or more of the preceding claims wherein the wheel bracket includes a receiving formation for complementarily receiving the friction reduction element.

6. A castor wheel assembly as claimed in any one or more of the preceding claims wherein the friction reduction element includes a securing formation for securing the friction reduction element relative the mounting member.

7. A castor wheel assembly as claimed in any one or more of the preceding claims wherein the friction reduction element includes a securing formation for securing the friction reduction element relative the wheel bracket.

8. A castor wheel assembly as claimed in claim 6 or 7 wherein the securing formation takes the form of a flange defined circumferentially about and extending upward and away from the friction reduction element.

9. A castor wheel assembly as claimed in claim 8 wherein the flange has a diameter measuring less than that of the friction reduction element.

10. A castor wheel assembly as claimed in claim 6 or 7 wherein the securing formation takes the form of an annular shaped formation having a flat upper surface.

11. A castor wheel assembly as claimed in claim 10 wherein the annular shaped formation has a diameter less than that of the friction reduction element.

12. A castor wheel assembly as claimed in claim 6 wherein the mounting bracket includes a receiving formation for complementarily receiving the securing formation.

13. A castor wheel assembly as claimed in claim 7 wherein the wheel bracket includes a receiving formation for complementarily receiving the securing formation.

14. A castor wheel assembly as claimed in 12 or 13 wherein the receiving formation includes a recess and further having a stepped configuration for complementarily receiving the securing formation.

15. A castor wheel assembly as claimed in any one or more of the preceding claims wherein the friction reduction element has a coefficient of friction value of less than about 0.3.

16. A castor wheel assembly as claimed in any one or more of the preceding claims which includes an interconnector for operatively interconnecting the mounting member, friction reduction element, and, wheel bracket.

17. A castor wheel assembly as claimed in claim 16 wherein the interconnector includes a bushing type element for in use, promoting swivelling of the wheel bracket relative the mounting member.

18. A friction reduction element for in use, allows swivelling of a wheel bracket member relative a mounting member of a castor wheel assembly, the friction reduction element further having a coefficient of friction value less than that of the wheel bracket member and/or mounting member.

19. A friction reduction element as claimed in claim 18 wherein the friction reduction element is substantially annular shaped.

20. A friction reduction element as claimed in claim 18 wherein the friction reduction element takes the form of a washer type element.

21. A friction reduction element as claimed in any one of claim 18 onwards wherein the wheel bracket member includes a receiving formation for complementarily receiving the friction reduction element.

22. A friction reduction element as claimed in any one of claim 18 onwards wherein the mounting member includes a receiving formation for complementarily receiving the friction reduction element.

23. A friction reduction element as claimed in any one of claim 18 onwards which includes a securing formation for securing the friction reduction element relative the mounting member.

24. A friction reduction element as claimed in any one of claim 18 onwards which includes a securing formation for securing the friction reduction element relative the wheel bracket.

25. A friction reduction element as claimed in claim 23 or 24 wherein the securing formation takes the form of a flange defined circumferentially about and extending upward and away from the friction reduction element.

26. A friction reduction element as claimed in claim 23 or 24 wherein the securing formation takes the form of an annular shaped formation having a flat upper surface.

27. A friction reduction element as claimed in claim 23 wherein the mounting member includes a receiving formation for complementarily receiving the securing formation for in use, keeping the friction reduction element in place.

28. A friction reduction element as claimed in claim 24 wherein the wheel bracket includes a receiving formation for complementarily receiving the securing formation for in use, keeping the friction reduction element in place.

29. A friction reduction element as claimed in claim 27 or 28 wherein the receiving formation includes a recess and further having a stepped configuration for complementarily receiving the securing formation.

30. A friction reduction element as claimed in any one of claim 18 onwards wherein the wheel bracket includes a seating formation defined an upper facing surface thereof for in use, seating the friction reduction element.

31. A friction reduction element as claimed in claim 18 onwards having a coefficient of friction value of less than about 0.3.

32. A friction reduction element as claimed in claim 18 onwards wherein the castor wheel assembly includes an interconnector for operatively interconnecting the mounting member, friction reduction element, and, wheel bracket.

33. A friction reduction element as claimed in claim 28 wherein the interconnector includes a bushing type element for in use, promoting swivelling of the wheel bracket relative the mounting member.