Articulated vehicle wheel tracking mechanism

• US 20040104555A1
• Filed: 05/30/2003
• Published: 06/03/2004
• Est. Priority Date: 12/01/2000
• Status: Active Grant

• Current Assignee: Trackaxle Pty Limited
• Original Assignee: Trackaxle Pty Limited
• Inventors: Atley, Kerry
• Granted Patent: US 7,219,913 B2
• Time in Patent Office: Days
• US Class Current: 280/426
• CPC Class Codes: B62D 13/025 the pivoted movement being initiated by the coupling means between tractor and trailer

Abstract

The invention provides a trailer for use as part of an articulated vehicle (15) with improved cornering characteristics. The trailer includes: a main chassis (18) connectable to a wheeled section (16) of the vehicle immediately ahead of the trailer so that the trailer is rotatable relative to the wheeled section (16) about a substantially upright first axis (19) in the main chassis (18); a sub-chassis (20) having ground-engaging wheels (21) mounted thereto, the sub-chassis (20) being connected to the main chassis (18) and pivotable about a substantially upright second axis (23) in the main chassis (18); and stop means arranged for limiting rotation of the sub-chassis (20) about the second axis (23) and away from a position of a longitudinal alignment with the main chassis (18). The stop means is movable responsively to relative rotation of the wheeled section (16) and the main chassis (18) about the first axis (19). In a preferred arrangement, some wheels on the sub-chassis (20) are steerable responsively to rotation of the sub-chassis (20) about the second axis (23).

Claims

1. A trailer for use as part of an articulated vehicle, the trailer including:

a main chassis connectable to a wheeled section of the vehicle immediately ahead of the trailer so that the trailer is rotatable relative to said wheeled section about a substantially upright first axis in the main chassis;

a sub-chassis having ground-engaging wheels mounted thereto, said sub-chassis being connected to the main chassis and pivotable about a substantially upright second axis in the main chassis;

stop means arranged for limiting rotation of said sub-chassis about said second axis and away from a position of longitudinal alignment with said main chassis,

wherein said stop means is movable responsively to relative rotation of said wheeled section and said main chassis about said first axis.

2. A trailer according to claim 1 having a plurality of pairs of ground engaging wheels longitudinally spaced apart on said sub-chassis and including steering means responsive to relative rotation of said sub-chassis and said main chassis about said second axis for steering at least one said pair relatively to said sub-chassis in such a sense as to tend to align said sub-chassis longitudinally with said main chassis.

3. A trailer according to claim 2 wherein a said pair of steerable wheels is mounted to a rigid axle, said axle is pivotally mounted to said sub-chassis and said pair of wheels is steerable by pivoting of said axle about a substantially upright third axis in said sub-chassis.

4. A trailer according to claim 3 wherein said steering means includes a first link connecting said axle and said main chassis.

5. A trailer according to any one of claims 1 to 4 further including:

a yoke mounted to said main chassis and bearing against said stop means; and

connecting means whereby said yoke is connected to said sub-chassis and movable in said main chassis responsively to rotation of said sub-chassis about said second axis.

6. A trailer according to claim 5 wherein:

said yoke is mounted for substantially longitudinal movement in the main chassis and has a slide surface extending in a direction substantially transverse to the main chassis;

a slider is included in said stop means and mounted in said main chassis so as to pivot around said first axis in concert with said wheeled section pivoting about said first axis; and

said slide surface bears against said slider.

7. A trailer according to claim 6 including two said yokes and two said connecting means each connecting means associated with one of said yokes and wherein when the sub-chassis is aligned with the main chassis for straight-ahead travel, the slider is located substantially at a transverse midpoint of the main chassis and respective said slide surfaces of both yokes bear on said slider, and wherein the connecting means, yokes and sub-chassis are so arranged that as one said yoke moves forward the other said yoke moves backward.

8. A trailer according to any one of claims 5 to 7 wherein the or each said connecting means includes a second link pivotally connected to said yoke and to said sub-chassis.

9. A trailer according to any one of claims 5 to 8 further including resilient means included in the or each said yoke and deflectable responsively to a contact force between said stop means and said yoke.

10. A trailer according to any one of claims 5 to 8 further including resilient means included in the or each said connecting means and deflectable responsively to a force transmitted by said connecting means to or from said sub-chassis.

11. A trailer according to any one of claims 1 to 4 further including:

a member mounted to said main chassis for movement relative thereto responsively to said rotation of said sub-chassis about said second axis; and

movement transmitting means whereby said movement of said member causes a corresponding movement of a follower means and said corresponding movement is limited according to the position of said stop means.

12. A trailer according to claim 11 wherein said movement transmitting means includes first and second hydraulic actuators operatively interconnected by hydraulic fluid conduits so that actuation of said first actuator by said movement of said member produces a corresponding movement by said second actuator of said follower means.

13. A trailer according to claim 12 further including a container having an internal space in fluid communication with a hydraulic fluid conduit connecting said hydraulic actuators and means whereby the volume of said space increases as hydraulic fluid pressure in said space increases.

14. A trailer according to any one of claims 11 to 13 including a telescoping link having a predetermined minimum length said link being arranged to cause said movement of said member responsively to said rotation of said sub-chassis in a particular direction when telescoped to said minimum length.

15. A trailer according to claim 14 wherein said telescoping link is one of two such telescoping links respectively arranged to cause said movement of said member responsively to said rotation of said sub-chassis in first and second opposing directions.

16. A trailer according to any one of claims 11 to 15 wherein said stop means includes a cam arranged to rotate in said main chassis about said first axis and adapted to be coupled to said wheeled section.

17. A trailer according to any one of claims 1 to 16 including further stop means for limiting to a fixed maximum value said angular rotation of said sub-chassis about said second axis and away from said position of alignment with said main chassis.

18. A trailer according to any one claims 1 to 17 further including second locking means whereby when said sub-chassis is in longitudinal alignment with said main chassis and any angular deviation from longitudinal alignment of said wheeled section and said main chassis is less than a specified value said locking means is engageable to lock said sub-chassis and said main chassis in longitudinal alignment for so long as said angular deviation from longitudinal alignment of said wheeled section and said main chassis remains less than said specified value.

19. A trailer according to any one of claims 1 to 18 further including third locking means which for so long as a reverse gear of said articulated vehicle is engaged locks said sub-chassis and said main chassis at such relative angular deflection about said second axis as exists when reverse gear is engaged.

21. An articulated vehicle including a trailer according to any one of claims 1 to 20.

20. A trailer for use as part of an articulated vehicle, the trailer including:

a main chassis;

a sub-chassis pivotable about a substantially upright first axis in the main chassis;

at least one assembly pivotable about a substantially upright second axis in the sub-chassis and including a rigid axle with ground engaging wheels thereon; and

a link secured to said assembly and said main chassis,

whereby in response to a rotation in one sense of said sub-chassis about said first axis, said link rotates said assembly about said second axis in such a sense as to steer said wheels in such a direction as to tend to reduce said rotation of sub-chassis during forward motion of said trailer.

22. Apparatus for operating a ground wheel steering means of a trailer mountable to a fifth wheel assembly of an articulated vehicle, said fifth wheel having a slot in which a kingpin of said trailer is receivable and retainable, said apparatus including:

a member arranged to pivot about an axis of said kingpin;

means whereby said ground wheel steering means is operated responsively to pivoting of said member about said axis;

drive means secured to said member and which depend from said trailer and are receivable in said slot.