GB2549824A

GB2549824A - Pivotable member

Info

Publication number: GB2549824A
Application number: GB1702612.1A
Authority: GB
Inventors: Philip Shuttleworth Kevin
Original assignee: Ifor Williams Trailers Ltd
Current assignee: Ifor Williams Trailers Ltd
Priority date: 2017-02-17
Filing date: 2017-02-17
Publication date: 2017-11-01
Anticipated expiration: 2037-02-17
Also published as: GB201702612D0; GB2549824B

Abstract

There is provided a pivotable member 10 for a brake compensator device. The pivotable member has a cylindrical bearing surface 12, which extends about a pivot axis 16, and a spherical bearing surface 14, which extends about a pivot point 18. Each of the cylindrical bearing surface and the spherical bearing surface is for forming a connection between the pivotable member and a brake actuator. The spherical bearing surface is formed intermediate two spaced apart portions of the cylindrical bearing surface such that the pivot point is coincident with the pivot axis. Either bearing surface may be discontinuous. The pivotable member may be U-shaped in cross-section. The pivotable member may include a central web 22 between two spaced apart flanges 24a,b, the flanges each forming one of the spaced apart portions. These flanges may include projections 26a,b which have the spherical bearing surface formed at their free ends. The pivotable member may have two apertures 28, 30 for connecting to a brake cable or rod. The apertures may be spherical recesses. The pivotable member is for use in trailers with either a single axle brake compensator device or a multi-axle brake compensator device.

Description

Pivotable member

TECHNICAL FIELD

The invention relates to a pivotable member. The invention particularly relates to a pivotable member for a brake compensator device.

BACKGROUND

Towed vehicles or trailers are often provided with arrangements to automatically apply the brakes thereof when the towing vehicle slows. Typically, the inertia of the towed vehicle applies the brakes via a brake actuator, which is connected via a brake compensator device to brake rods or brake cables leading to separate braking devices on individual wheels of the towed vehicle. The brake compensator device has the function of equalising the force applied to a number of braking devices in a mechanically actuated braking system. Multi-axle brake compensator assemblies are complex and require multiple components to achieve equal distribution of the force applied to the braking devices. A compensator device may also be used in any other mechanism where forces must be equally or proportionally distributed between elements of that mechanism.

Embodiments of the invention are intended to at least mitigate one or more problems associated with known arrangements.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a pivotable member for a brake compensator device, the pivotable member comprising: a cylindrical bearing surface extending about a pivot axis; and a spherical bearing surface extending about a pivot point, wherein each of the cylindrical bearing surface and the spherical bearing surface is for forming a connection between the pivotable member and a brake actuator, i.e. any component configured to impart a braking force to the pivotable member, the spherical bearing surface being formed intermediate two spaced apart portions of the cylindrical bearing surface such that the pivot point is coincident with the pivot axis. The invention provides the appropriate degrees of freedom for different brake compensator assemblies, including single axle brake compensator assemblies and multi-axle brake compensator assemblies. This is because the pivotable member is able to pivot about a fulcrum having either a cylindrical axis or a spherical axis.

In certain embodiments, the cylindrical bearing surface and/or the spherical bearing surface may be a discontinuous surface. Additionally or alternatively, the pivotable member may be substantially U-shaped in cross section.

Optionally, each of the cylindrical bearing surface and the spherical bearing surface may be formed about at least a portion of a periphery of an opening extending through the pivotable member. The opening may facilitate connection of the pivotable member to the brake actuator or the like.

The pivotable member may comprise a central web intermediate two spaced apart flanges, with each of the flanges forming one of the spaced apart portions of the cylindrical bearing surface and at least a respective portion of the spherical bearing surface. Additionally, each of the flanges may comprise a respective projection extending therefrom, each of the projections forming the spaced apart portions of the cylindrical bearing surface and the respective portions of the spherical bearing surface. The respective portions of the spherical bearing surface may be formed at free ends of the projections. Each of the projections may be a curved projection. Forming the projections as curved projections may improve the strength of the projections and allow for forming the pivotable member by press forming.

In certain embodiments, the pivotable member may comprise two apertures extending therethrough. The apertures may be equispaced and opposite one another about the pivot axis for forming a connection between the pivotable member and respective brake cables or any component configured to transmit the braking force from the pivotable member to braking devices. The apertures may be elongate apertures. The apertures may allow adjustment or tilting in position of abutment retention members, e.g. spherical bolt heads, used to connect the pivotable member to the brake cables or the like. Additionally, each of the apertures may be formed in a respective curved recess formed in the pivotable member, each the recesses extending about a respective further pivot point. The further pivot points may lie in a common plane with the pivot axis. Each of the recesses may a spherical recess. The recesses may facilitate the aforementioned adjustment or tilting in position of the abutment retention members.

In certain embodiments, the pivotable member may be formed as a single piece of pressed metal, e.g. steel.

According to a second aspect of the invention there is provided a brake compensator device comprising a pivotable member as described above and brake actuator or the like having a fulcrum upon which the pivotable member is supported by abutment of the fulcrum against either of the cylindrical bearing surface or the spherical bearing surface. The fulcrum may comprise a fulcrum bearing surface which is complementary to either of the cylindrical bearing surface or the spherical bearing surface. As will be understood, the fulcrum bearing surface need only be cooperable with either of cylindrical bearing surface or the spherical bearing surface.

According to a third aspect of the invention there is provided a trailer or towed vehicle comprising a pivotable member as described above. According to a fourth aspect of the invention there is provided a trailer or towed vehicle comprising a brake compensator device as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of example only, with reference to the accompanying figures, in which:

Figure 1 is a perspective view of a pivotable member according to an embodiment of the invention;

Figure 2 is a longitudinal cross sectional view of the pivotable member of Figure 1 taken through the centre of the pivotable member;

Figure 3 is a transverse cross sectional view of the pivotable member of Figure 1 taken through the centre of the pivotable member;

Figure 4 is a perspective view of a brake compensator device according to an embodiment of the invention for a single axle braking system;

Figure 5 is a perspective view of a brake compensator device according to an embodiment of the invention for a tandem axle braking system; and

Figure 6 is a perspective view of a brake compensator device according to an embodiment of the invention for a further tandem axle braking system.

DETAILED DESCRIPTION

Figures 1 to 3 show a pivotable member 10 according to an embodiment of the invention. The pivotable member 10 has particular application in a brake compensator device 40 (see Figure 4). The pivotable member 10 comprises a cylindrical bearing surface 12 and a spherical bearing surface 14. The cylindrical bearing surface 12 extends about a pivot axis 16. The spherical bearing surface 14 extends about a pivot point 18. Crucially, the spherical bearing surface 14 is formed intermediate two spaced apart portions 12a, 12b of the cylindrical bearing surface 12. In use, each of the cylindrical bearing surface 12 and the spherical bearing surface 14 is configured to form a connection between the pivotable member 10 and a brake actuator 42 (see Figure 4) or the like. This connection is described in more detail below.

In the illustrated embodiment, the pivotable member 10 is substantially U-shaped in cross section. To this end, the pivotable member 10 comprises a central web portion 22 spanning between two spaced apart flanges 24a, 24b. The flanges 24a, 24b may be substantially parallel to one another and substantially perpendicular to the central web portion 22. An opening 20 may extend through a region of the pivotable member 10 for facilitating connection of the brake actuator 42. The opening 20 may extend though the central web portion 22 and/or the flanges 24a, 24b. Thus, the web portion 22 and/or the flanges 24a, 24b may define a periphery of the opening 20. As shown in the accompanying figures, the cylindrical surface 12 and the spherical bearing surface 14 may be formed about the periphery of the opening 20, or at least about a portion of the periphery of the opening 20.

Each of the flanges 24a, 24b may comprise a respective projection 26a, 26b extending from a surface thereof. The projections 26a, 26b may be curved projections. Each of the projections 26a, 26b may extend from the flanges 24a, 24b in a direction substantially toward the other of the projections 26a, 26b. A gap may be formed intermediate the projections 26a, 26b. In alternative embodiments, each of the projections 26a, 26b may extend from the flanges 24a, 24b in a direction substantially away from the other of the projections 26a, 26b. In the illustrated embodiment, it is on the projections 26a, 26b that the cylindrical bearing surface 12 and the spherical bearing surface 14 are formed. More specifically, the spherical bearing surface 14 is formed at free ends 28a, 28b (see Figure 3) of the projections 26a, 26b, i.e. ends of the projections 26a, 26b furthest form the flanges 24a, 24b. The cylindrical bearing surface 14 is formed on respective regions of each of the projections 26a, 26b, intermediate the free ends 28a, 28b and the flanges 24a, 24b. Thus, as will be understood, either or both of the cylindrical bearing surface 12 and the spherical bearing surface 14 may be a discontinuous surface. The cylindrical surface 12 is a surface having curvature in one direction only. The spherical surface 14 is a surface having curvature in all directions towards a common side of the pivotable member 10, i.e. the spherical bearing surface 14 is a synclastic surface. As shown in the accompanying figures, the spherical bearing surface 14 may be formed such that the pivot point 18 is coincident with the pivot axis 16, i.e. the pivot point 18 lies on the pivot axis 16.

The pivotable member 10 may further comprise apertures 28, 30 extending therethrough for forming a connection between the pivotable member 10 and brake cables 44 (see Figure 4) or the like. This connection is described in more detail below. The apertures 28, 30 may be formed in the pivotable member 10 opposite one another about the pivot axis 16 (and hence also opposite one another about the pivot point 18), with each of the apertures 28, 30 equispaced about the pivot axis 16. In use, being spaced in this manner allows for equal tension to be distributed to the brake cables 44 attached to the pivotable member 10. Moreover, the apertures 28, 30 may allow for adjustment, tilting or rotation in position of brake cable retention members 46, e.g. spherical nuts, used to connect the brake cables 44 to the pivotable member 10. Each of the apertures 28, 30 maybe formed in a respective curved recess 32 (see Figure 2), each recess extending about a respective further pivot point 34. In certain embodiments, each of the curved recesses 32 may be a spherical recess. However, in alternative embodiments, each of the curved recesses 32 may be a cylindrical recess. Each of the further pivot points 34 may lie in a common plane with the pivot axis 16 and/or the pivot point 18, as this may facilitate the equal distribution of a force applied to pivotable member 10 to the brake cables 44.

Figure 4 shows a brake compensator device 40 according to an embodiment of the invention. The brake compensator device 40 has particular application in a braking system for a single axle trailer having two braking devices. Figure 4 shows the pivotable member 10 connected to the brake actuator 42 and the brake cables 44. The brake actuator 42 may pass through the opening 20 in the pivotable member 10, forming a connection with the pivotable member 10 by abutment of a brake actuator retention member 48 against the spherical bearing surface 14. The brake actuator retention member 48 may be a spherical nut engaged with the brake actuator 42, e.g. by threaded engagement.

In use, a braking force is exerted on the brake actuator 42 to actuate braking devices (not shown) connected to the brake cables 44. The force exerted on the brake actuator 42 is transmitted therefrom by abutment of the brake actuator retention member 48, against the spherical bearing surface 14. As shown in Figure 4, the brake actuator retention member 48 may provide a fulcrum having a spherical axis upon which pivotable member 10 is supported. Consequently, the pivotable member 10 pivots about the brake actuator retention member 48, to divide and distribute the braking force exerted on the brake actuator 42 equally to each of the brake cables 44. The braking force is transmitted from the pivotable member 10 by abutment of the brake cable retention members 46 against bearing surfaces provided by the curved recesses 32 to the brake cables 44.

The shaping of the apertures 28, 30 and the formation of the recesses 32, in combination with the brake cable retention members 46, may reduce the occurrence kinking or abnormal bending of the brake cables 44 or the like when the pivotable member 10 pivots about the brake actuator retention member 48.

Figure 5 shows a brake compensator device 50 according to a further embodiment of the invention. The brake compensator device 50 has particular application in a braking system for a tandem axle trailer having four braking devices. The brake compensator device 50 may comprise a beam 52 having a pair of free ends 52a, 52b. Figure 5 shows a pair of pivotable members 10 connected to the brake actuator 42 via the beam 52. The brake actuator 42 may pass through an opening 54 in the beam 52, forming a connection with the beam 52 by abutment of the brake actuator retention member 48 against a bearing surface of the beam 52, e g. in a similar manner as described above regarding abutment of the brake actuator retention member 48 against the spherical bearing surface 14. The pivotable members 10 may be connected to the beam 52 by abutment of the free ends 52a, 52b against the cylindrical bearing surfaces 12 of the respective pivotable members 10. Each of the free ends 52a, 52b may form a curved surface that may engage with a respective cylindrical bearing surface 12.

In use, the force exerted on the brake actuator 42 is transmitted therefrom by abutment of a brake actuator retention member 48 against the bearing surface of the beam 52.

The braking force is transmitted from the beam 52 by abutment of the free ends 52a, 52b against the cyiindricai bearing surfaces 12 of the respective pivotabie members 10. As shown in Figure 5, each of the free ends 52a, 52b may provide a fuicrum having a sphericai axis upon which respective pivotabie members 10 are supported. The pivotabie members 10 pivot about the free ends 52a, 52b, to divide and distribute the braking force, as described above with reference to Figure 4.

Figure 6 shows a brake compensator device 60 according to another embodiment of the invention. The brake compensator device 60 has particuiar appiication in a braking system for a three axie traiier having six braking devices. The brake compensator device 60 may comprise a frame 62. Figure 6 shows three pivotabie members 10 connected to the brake actuator 42 via the frame 62. The brake actuator 42 may pass through an opening 64 in frame 62, forming a connection with the frame 62 by abutment of the brake actuator retention member 48 against a bearing surface of the frame 62, e.g. in a simiiar manner as described above regarding abutment of the brake actuator retention member 48 against the sphericai bearing surface 14. The pivotabie members 10 may be connected to the frame 62 by abutment of one or a piuraiity of protuberances 66 extending from the frame 62 against the sphericai bearing surfaces 14 of the respective pivotabie members 10. Each of the protuberances 66 may provide a curved surface that may engage with a respective sphericai bearing surface 14. in use, the force exerted on the brake actuator 42 is transmitted therefrom by abutment of a brake actuator retention member 48 against the bearing surface of the frame 62. The braking force is transmitted from the frame 62 by abutment of the protuberances 66 against the sphericai bearing surfaces 14 of the respective pivotabie members 10. Each of the protuberances 66 may provide a fuicrum having a sphericai axis upon which respective pivotabie members 10 are supported. The pivotabie members 10 pivot about the protuberances 66, to divide and distribute the braking force, as described above with reference to Figure 4.

The invention may provide a simpiified arrangement for muiti-axie brake compensator devices, requiring fewer components compared to known arrangements. Advantageousiy, the arrangements disciosed herein may be easier and quicker to assembie and maintain, compared to those for existing muiti-axie brake compensator devices. Notwithstanding the advantage of having a singie part suitabie for pivoting about a fuicrum having either a cyiindricai axis or a sphericai axis, forming the spherical bearing surface 14 at the free ends 28a, 28b of the projections 26a, 26b enables a spherical bearing surface 14 to be formed without the use of deep press forming. Deep press forming requires heavy and powerful tooling and greater ductility in the material being formed. Thus, embodiments of the invention may allow for greater choice in selection of material from which to form the pivotable member 10 and/or lower tonnage of press tooling. Without the use of deep press forming, there is also less thinning of the chosen material and a reduced susceptibility to tearing during forming.

The invention is not restricted to the details of any foregoing embodiments, e.g. the pivotable member 10 need not be U-shaped in cross section. Moreover, the pivotable member 10 may comprise the central web 22 and the flanges 24a, 24b without forming a U-shaped cross section. In certain embodiments, the central web 22 and the flanges 24a, 24b may form an l-shaped cross section. While the illustrated embodiment is formed by use of press forming, the pivotable member 10 may be formed by any suitable means, e.g. casting.

The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings). The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims.

All of the features disclosed in this specification (including any accompanying claims and drawings), may be combined in any combination, except combinations where at least some of such features are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Claims

1. A pivotable member for a brake compensator device, the pivotable member comprising: a cylindrical bearing surface extending about a pivot axis; and a spherical bearing surface extending about a pivot point, wherein each of the cylindrical bearing surface and the spherical bearing surface is for forming a connection between the pivotable member and a brake actuator or the like, the spherical bearing surface being formed intermediate two spaced apart portions of the cylindrical bearing surface such that the pivot point is coincident with the pivot axis.

2. A pivotable member according to claim 1, wherein the cylindrical bearing surface and/or the spherical bearing surface is a discontinuous surface.

3. A pivotable member according either of claims 1 or 2, wherein the pivotable member is substantially U-shaped in cross section.

4. A pivotable member according to any preceding claim, wherein each of the cylindrical bearing surface and the spherical bearing surface is formed about at least a portion of a periphery of an opening extending through the pivotable member.

5. A pivotable member according to any preceding claim, wherein the pivotable member comprises a central web intermediate two spaced apart flanges, each of the flanges forming one of the spaced apart portions of the cylindrical bearing surface and a respective portion of the spherical bearing surface.

6. A pivotable member according to claim 5, wherein each of the flanges comprise a respective projection extending therefrom forming the spaced apart portions of the cylindrical bearing surface and the respective portions of the spherical bearing surface.

7. A pivotable member according to claim 6, wherein the respective portions of the spherical bearing surface are formed at free ends of the projections.

8. A pivotable member according to either of claims 6 or 7, wherein each of the projections is a curved projection.

9. A pivotable member according to any preceding claim, wherein the pivotable member comprises two apertures extending therethrough, the apertures being equispaced and opposite one another about the pivot axis for forming a connection between the pivotable member and a respective brake cable or brake rod.

10. A pivotable member according to claim 9, wherein each of the apertures is formed in a respective curved recess that extends about further respective pivot point, each of the further pivot points lying in a common plane with the pivot axis.

11. A pivotable member according to claim 10, wherein each of the curved recesses is a spherical recess.

12. A pivotable member according to any preceding claim, wherein the pivotable member is formed as a single piece of pressed metal.

13. A brake compensator device comprising a pivotable member according to any preceding claim and a brake actuator or the like having a fulcrum upon which the pivotable member is supported by abutment of the fulcrum against either of the cylindrical bearing surface or the spherical bearing surface.

14. A brake compensator device according to claim 13, wherein the fulcrum comprises a fulcrum bearing surface complementary either of the cylindrical bearing surface or the spherical bearing surface.

15. A trailer or towed vehicle comprising either a pivotable member according to any of claims 1 to 12 or a brake compensator device according to claim 13 or 14.