AU766562B2

AU766562B2 - A jockey wheel

Info

Publication number: AU766562B2
Application number: AU27596/02A
Authority: AU
Inventors: Frederick Charl Breytenbach
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-26
Filing date: 2002-03-22
Publication date: 2003-10-16
Anticipated expiration: 2022-03-22
Also published as: ZA200103436B; AU2759602A

Description

ADAMS ADAMS PATENT ATTORNEYS

PRETORIA

A& A Ref No: 143628 REPUBLIC OF SOUTH AFRICA Patents Act, 1978 COMPLETE SPECIFICATION (Section 30 Regulation 28) FORM P7 21 01 OFFICIAL APPLICATION NO 20013436 51 INTERNATIONAL CLASSIFICATION B62D 71 FULL NAME(S) OF APPLICANT(S) BREYTENBACH, Frederick Charl 72 FULL NAME(S) OF INVENTOR(S) BREYTENBACH, Frederick Charl 54 TITLE OF INVENTION 26 April 2001 22 LODGING DATE A JOCKEY WHEEL -1- -1111V-1 71- .1 I 461k& aiiz THIS INVENTION relates to towed vehicles such as caravans, trailers, boat trailers and the like. It relates in particular to a third wheel assembly for such towed vehicles. Such a third wheel assembly is referred to hereinafter as a jockey wheel assembly.

A problem associated with the third wheel, or jockey wheel, of a trailer or caravan is-that the wheel can generally be raised to a limited distance above the ground. -If the trailer or caravan is pulled over rough terrain, the wheel can strike a rock or a similar upwardly projecting portion :of the terrain as it passes beneath the towing vehicle and the trailer while the vehicle is moving. This can cause damage to the jockey wheel. It is an object of the invention to address this problem.

According to a first aspect of the invention there is provided a jockey wheel assembly for a towed vehicle, the assembly including a wheel mounting mechanism by which a jockey wheel is rotatably mountable on the assembly, and a displacement mechanism operable, when the jockey wheel assembly is mounted on a towed vehicle, to displace the wheel mounting mechanism SUBSTITUTE COPY vertically and whereby the jockey wheel can be pivoted arcuately upwardly and downwardly with respect to the wheel mounting mechanism.

The assembly may include a locking mechanism for locking the wheel mounting mechanism in a predetermined position.

The assembly may include a jockey wheel mounted on thewheel mounting mechanism.

The displacement mechanism may be arranged first to lift the assembly vertically and then to pivot the mechanism arcuately upwardly. In this way, the wheel mounting mechanism will be raised and the folded or pivoted upwardly, for example rearwardly. Instead, the displacement mechanism may be arranged to pivotally displace the wheel mounting mechanism upwardly, for example rearwardly or forwardly, and then to lift the mechanism vertically.

Because of the additional pivot action, a jockey wheel mounted on the wheel S mounting mechanism will be raised further from the ground than is the case for a wheel mounting mechanism which is displaceable only vertically upwardly and downwardly in conventional fashion.

Thus, the displacement mechanism may be operable to displace the assembly vertically, and then to pivotally displace the mechanism arcuately upwardly. Instead, the displacement mechanism may be operable 4 to pivotally displace the mechanism arcuately upwardly and then to lift the mechanism vertically.

The displacement mechanism may include a pair of telescopically engaged members and the wheel mounting mechanism may be linked to one of the telescopically engaged members. Thus, by telescopic displacement of the members relative to one another, the wheel mounting mechanism will be raised and lowered. The displacement mechanism may include an outer and an inner telescopic member and the wheel mounting mechanism may be linked to the inner telescopic member. The wheel mounting mechanism may be linked to the inner telescopic member by means of a pivotal link so that the wheel mounting mechanism is pivotally displaceable along an arc relative to the inner telescopic member. The locking mechanism may then be operable to lock the wheel mounting S"mechanism in a predetermined position with respect to the inner telescopic member.

The displacement mechanism may include a screw-jack mechanism which is operable to displace the telescopically engaged members relative to one another. The screw-jack mechanism may include a screw-threaded shank mounted within, and co-axial with, the inner telescopic member, and rotatably secured to the outer telescopic member by means of an upper collar, which co-operates with a nut held captive within -r i~ :~~y~jir;ii~i~ii~uZui the inner telescopic member. The mechanism may then include a crank handle which is secured to the shank and which is operable to rotate the shank. The crank handle may be releasably attached to an upper end of the shank.

Thus, rotation of the crank handle will rotate the screwthreaded shank and displace the nut and the attached inner telescopic member upwardly or downwardly relative to the outer telescopic member.

S. The wheel mounting mechanism may include at least one wheel mounting arm and the,: or each, arm may be pivotally linked to the inner telescopic member near its operatively lower end. The upper edge of the, or each, arm adjacentthe pivotal link may be curved to form a cam surface.

:The lower end of the outer telescopic member may then be provided with an .r outer collar which is positioned to interact with the, or each, cam surface when the inner telescopic member is displaced upwardly, the profile of the cam surfaces being arranged so that, as the inner telescopic member is displaced upwardly relative to the outer telescopic member so that the, or each, cam surface makes contact with the outer collar, cam action between the cam surfaces and the collar causes the, or each, wheel mounting arm to be pivoted arcuately upwardly.

Accordingly, in use, the jockey wheel mounted at the opposite l~;n~i~r r--i-12Z-A Wa 6W. 6 end of the or each wheel mounting arm will be pivoted arcuately upwardly relative to the axes of the telescopic members.

Conversely, lowering the wheel mounting mechanism will cause the cam surfaces of the, or each, wheel mounting arm to move away from the collar so that the, or each, wheel mounting arm will swing or pivot downwardly under its- own weight so that the jockey wheel is again in an operative, ground-engaging position. The locking mechanism will then lock the wheel-mounting mechanism in its ground engaging position.

The wheel mounting assembly may include two wheel mounting .arms and the locking mechanism may comprise a pair of engageable pins, one extending- between the wheel mounting arms and one secured to the inner telescopic member.

:Thus the first.locking pin may extend between the arms and the inner telescopic member may be provided with a second locking pin, the pins being arranged to engage and lock the wheel mounting assembly in its ground-engaging position when the inner telescopic member has been displaced downwardly.

S: In particular, the first locking pin may extend between the wheel mounting arms adjacent operatively upper ends of the arms and the second 7 locking pin may be slidably arranged to extend substantially at right angles to the first locking pin through a first and a second opening in the inner telescopic member. The second pin will be of a length which allows it to project outwardly from the openings.

The second locking pin may be provided, at its end adjacent the first opening, with a cam follower which is positioned and shaped to interact with the outer collar when the inner telescopic member is displaced upwardly so as to displace, by a cam action, the second locking pin outwardly or away from the first locking pin. The second locking pin may also be provided with a biasing mechanism, such as a compression spring, which is operable to bias the second locking pin to project from the second opening.

Thus, the second locking pin may be provided with a biasing mechanism, which is operable to bias the second locking pin towards the first locking pin.

The pivotal link, and the first and second locking pins may be positioned so that, when the inner telescopic member moves downwardly, cam action between the cam follower and the collar, and the biasing means, cause the second locking pin to be displaced towards the first locking pin and to project from the second opening below the first locking pin to lock the first locking pin against the second thereby locking the wheel mounting

AW

8 arms. When the inner telescopic member is displaced upwardly, the cam follower interacts with the collar to displace the second locking pin towards the first opening thereby withdrawing it into the second opening so that the wheel mounting arms are free to pivot upwardly.

The invention extends to a towed vehicle which includes a jockey wheel assembly as hereinbefore described.

~The towed vehicle may be a trailer, a boat trailer, a caravan or the like.

According to a second aspect of the invention there is provided a method of preventing or reducing damage to a jockey wheel of a K: towed vehicle when the vehicle is towed, the method including the steps, in any order, of raising the jockey wheel vertically from a ground engaging position; and displacing the jockey wheel arcuately upwardly.

The method may include the steps of raising the jockey wheel vertically to a first raised position and then displacing the jockey wheel arcuately upwardly to a second position which is above the first position.

The invention is now described by way of example with 9 reference to the accompanying diagrammatic drawings in which Figure 1 shows a trailer and a jockey wheel assembly in accordance with the invention with the jockey wheel in its non-operable, raised position; Figure 2 shows a part of the trailer of Figure 1 and the jockey wheel assembly with the jockey wheel in its operative, ground-engaging position; and :.ig sFigure 3 shows a sectional view of the jockey wheel assembly of Figures 1 and 2 on a larger scale.

Referring to the drawings, reference numeral 10 generally indicates a jockey wheel assembly in accordance with the invention having a jockey wheel 12.:In-Figures 1 and 2, the assembly is shown mounted on a trailer 20 in conventional fashion.

The assembly 10 comprises an outer, square-tubular steel pillar 14 with a cross-section of approximately 60 mm and a thickness of 4 mm in which a round-tubular steel wheel support post 16 is telescopically mounted and axially displaceable. The post 16 has a diameter of 48 mm and a wall thickness of 4 mm. Two matching steel wheel mounting arms 18, 19 are linked to the lower end of the support post 16 by a pivotal link in the form of a pivot pin 26 which extends through aligned openings 28 at the bottom of the support post 16 so that the arms 18, 1 9 and the jockey wheel 12 are pivotally displaceable in the direction of the arrows 30, 32. The I. r L- r*j~i~ii~iilr i.l~ jockey wheel 12 is mounted at the ends of the arms 18, 19 on an axle in conventional fashion.

In Figure 1 of the drawings, the jockey wheel 12 is shown raised off the ground and in Figure 2 the jockey wheel 12 is in its lowered, ground-engaging position. Steel mounting brackets 13, 15 serve to mount the assembly 10 on a trailer, caravan or the like. Each bracket has •dimensions of about 130 x 50 x 10 mm.

Telescopic displacement of the post 16 within the pillar 14 *.i takes place screw-jack, fashion. A screw-threaded, steel shank 38 approximately 400 mm long is axially located within the pillar 14 by means of a collar 40 closing -off the upper end of the pillar 14. A nut 44 is fast with, and located inside, the upper end of the support post 16 and is engaged with the screw threaded shank 38. A crank handle 44 is attached to the upper end of the shank 38. In the embodiment depicted in the drawings, the crank handle is straight. It has a turning lever 45 and is connected to the shank 38 at its end remote from the lever 45. In another embodiment (not shown) it is broadly S-shaped and is about 250 mm long with a thickness of 5 mm and a width of 30 mm. Thus rotation of the crank handle 44 will displace the support post 16 upwardly and downwardly to lift or lower the wheel 12.

i. .n~ 11 A hexagonal, stick first locking pin 46 with a length of 90 mm extends through a pair of opposed hexagonal openings in the support post 1 6 slightly above the pivot pin 26. The locking pin 46 is spring biased in the direction of the arrow 50 by means of a compression spring 52. A cam follower 54 with a sloping cam face 56 projects upwardly from one end of the pin 46 and is positioned to interact cam-fashion with a collar 58 at the lower end of the pillar 14. The collar has an outer diameter of about 80 mm.

~.Thus, displacement of the wheel support post 16 upwardly in the direction :of the arrow 60 will cause-the hexagonal pin 46 to be withdrawn in the direction of the arrow% 62.a-nd displacement of the wheel support post 1 6 downwardly in the direction of the arrow 64 will allow the spring 52 to displace the pin 46 in the direction of the arrow 'A second locking pin 65 extends between the wheel support arms 18, 19 at their ends remote from the wheel 1 2. The locking pin 65 is positioned so-that, when the wheel 1 2 is in its ground engaging position, as shown in Figure 2, the locking pin 65 is positioned above the hexagonal pin 46. Accordingly, when the-hexagonal locking pin 46 has been displaced in the direction of the arrow 50, it will project from the support post 16 below the second locking pin 65 and engage with it to lock the arms 1 8, 1 9 and hence the wheel 1 2, in its ground engaging position.

The arms 18, 1 9 include upper, curved cam faces 68 which are engageable with the collar 58 when the support post 1 6 is displaced upwardly. The cam faces 68 are shaped so that, as the support post 1 6 is displaced upwardly relative to the pillar 1 4, engagement of the cam faces 68 with the collar 58 pivotally displaces the wheel support arms 18, 1 9 and hence the wheel 12, arcuately upwardly in the direction of the arrow 30 to the position shown in Figure 1.

In use, the wheel support arms 18, 19 are in the position shown in Figure 1 when the trailer or caravan is being towed. To unhitch the trailer or caravan, the crank handle 44 is rotated counterclockwise and the support post 1 6 is displaced downwardly. Initially, as the post 1 6 moves *too downwardly, the wheel .12 pivots downwardly under its own weight in the direction of the arrow'32. as the cam faces 68 move away from the collar :58. This positions the wheel 12 in its operative ground-engaging position relative to the pillar 14 and support post 1 6 as shown in Figure 2. It also positions the second locking pin 65 above the hexagonal first locking _pin 46. As the support post 1 6 is displaced further, displacement of the cam face 56 relative to the collar 58 allows the spring 52 to urge the pin 46 in the direction of the arrow 50 so that the second locking pin 65 engages with the end of the first hexagonal locking pin 46 to lock the wheel 12 in. its operative, ground-engaging position. The crank handle 44 is then rotated further un til the wheel 1 2 is engaged with the ground.

.ns 4 -nr- -a-4-n-n- 13 It is an advantage of the invention illustrated that the jockey wheel assembly allows a jockey wheel not only to be lifted above the ground in conventional fashion but also to be pivoted or folded further upwardly into a position in which it is less likely to be damaged by unevenness in the terrain over which the trailer, caravan or the like is being towed.

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Claims

1. A jockey wheel assembly for a towed vehicle, the assembly including a wheel mounting mechanism by which a jockey wheel is rotatably mountable on the assembly, and a displacement mechanism operable, when the jockey wheel assembly is mounted on a towed vehicle, to displace the wheel mounting mechanism vertically and whereby the jockey wheel is further retracted and is deployed by being pivoted arcuately upwardly and downwardly, relative to the displacement mechanism. 1

2. A jockey wheel assembly, as claimed in Claim 1, which includes a locking mechanism for locking the wheel mounting mechanism in a predetermined position.

3. A jockey wheel assembly, as claimed in Claim 1 or Claim 2, which includes the jockey wheel mounted on the wheel mounting mechanism.

4. A jockey wheel assembly, as claimed in any one of Claims 1 to 3 in which the displacement mechanism is operable to pivotally displace the mechanism arcuately upwardly and then to lift the mechanism vertically. A jockey wheel assembly, as claimed in Claim 3 or Claim 4, in which the displacement mechanism includes a pair of telescopically engaged ~z .,4*oil, members and the wheel mounting mechanism is linked to one of the telescopically engaged members.

6. A jockey wheel assembly, as claimed in Claim 5, in which the displacement mechanism includes an outer and an inner telescopic member and the wheel mounting mechanism is linked to the inner telescopic member.

7. A jockey wheel assembly, as claimed in Claim 6, in which the wheel mounting mechanism is linked to the inner telescopic member by means of a pivotal link so that the wheel mounting mechanism is pivotally displaceable along an arc relative to the inner telescopic member.

8. A jockey wheel assembly, as claimed in any one of Claims 5 to 7 inclusive, in which the displacement mechanism further includes a screw-jack mechanism which is operable to displace the telescopically engaged members relative to one another.

9. A jockey wheel assembly, as claimed in Claim 8, in which the screw-jack mechanism includes a screw-threaded shank mounted within, and co- -20 axial with, the inner telescopic member, and rotatably secured to the outer telescopic member by means of an upper collar, which co-operates with a nut held captive within the inner telescopic member. 16 A jockey wheel assembly, as claimed in Claim 9, which includes a crank handle which is secured to the shank and which is operable to rotate the shank.

11. A jockey wheel assembly, as claimed in Claim 10, in which the crank handle is releasably attached to an end of the shank.

12. A jockey wheel assembly, as claimed in any one of Claims 6 to 11 inclusive, in which the wheel mounting mechanism includes at least one wheel mounting arm and the, or each, arm is pivotally linked to the inner telescopic member near its operatively lower end.

13. A jockey wheel assembly, as claimed in Claim 12, in which an upper edge of the or each arm adjacent the pivotal link is curved to form a cam surface. 00

14. A jockey wheel assembly, as claimed in Claim 13, in which the lower end of the outer telescopic member is provided with an outer collar which is positioned to interact with the, or each, cam surface when the inner telescopic member is displaced upwardly, the profile of the cam surfaces being arranged so ooo• that, as the inner telescopic member is displaced upwardly relative to the outer S telescopic member, so that the, or each, cam surface makes contact with the outer collar, cam action between the cam surfaces and the collar causes the, or each, wheel mounting arm to be pivoted arcuately upwardly. "A A 17 A jockey wheel assembly, as claimed in Claim 13 or Claim 14, in which the wheel mounting assembly includes two wheel mounting arms and the locking mechanism comprises a pair of engageable pins, one extending between the wheel mounting arms and one secured to the inner telescopic member.

16. A jockey wheel assembly, as claimed in Claim 15, in which the first locking pin extends between the wheel mounting arms adjacent operatively upper ends of the arms and the second locking pin is slideably arranged to extend substantially at right angles to the first locking pin through a first and a second opening in the inner telescopic member.

17. A jockey wheel assembly, as claimed in Claim 16, in which the second locking pin is provided, at its end adjacent the first opening, with a cam follower which is positioned and shaped to interact with the outer collar when the 9 inner telescopic member is displaced upwardly so as to displace, by a cam 99 9. action, the second locking pin away from the first locking pin.

18. A jockey wheel assembly, as claimed in Claim 16 or Claim 17, in which the second locking pin is provided with a biasing mechanism, which is operable to bias the second locking pin towards the first locking pin. *°99

19. A jockey wheel assembly, as claimed in Claim 18, in which the biasing mechanism is a spring. A towed vehicle which includes a jockey wheel assembly, as claimed in any one of the preceding claims.

21. A method of preventing or reducing damage to a jockey wheel of a towed vehicle as claimed in any one of the above claims when the vehicle is towed, the method including, in any order, the steps of raising the jockey wheel vertically from a ground engaging position; and displacing the jockey wheel arcuately upwardly.

22. A method as claimed in Claim 21 which includes the steps of raising the jockey wheel vertically to a first raised position and then displacing the jockey wheel arcuately upwardly to a second position which is above the first :15 position. go

23. A jockey wheel assembly as claimed in Claim 1, substantially as herein described and illustrated.

24. A towed vehicle as claimed in Claim 20, substantially as herein described and illustrated. A method as claimed in Claim 21, substantially as herein described and illustrated. W ft W 19

26. A new jockey wheel assembly, a new towed vehicle or a new method, substantially as herein described. SS 0 0000 0000 0* S. 0S 0 S SS@* S SS S S S 55 S. 55 S S S S 5k S S 55 S 5.55 S. S S 5* 5S SS 4