WO1997037864B1

WO1997037864B1 - Anti-creep device for a trailer with air springs

Info

Publication number: WO1997037864B1
Application number: PCT/US1997/005976
Authority: WO
Filing date: 1997-04-10
Publication date: 1997-11-06

Abstract

An anti-creep device for a trailer includes a support arm (250) adapted to be mounted to a trailer frame (14) proximate to a trailer axle (16) for rotational movement between a retracted position and an extended position. The support arm (250) includes a plurality of notches (252) extending along a length thereof. A support member (236) is adapted to be connected to the suspension and has at least one surface for receiving one of the support arm notches (252) when the support arm is in the extended position to prevent movement of the axle (16) toward the trailer frame (14) and thereby prevent the trailer frame from creeping. The notches (252) of the support arm (250) in the retracted position are disengaged from the support member (236) so that the axle is free to move with respect to the frame. An actuator (80) is associated with the support arm for rotating the arm at least to the extended position to thereby lock the frame at a selected height when the frame is raised with respect to the axle.

Claims

AMENDED CLAIMS[received by the Internationai Bureau on 30 September 1997 (30.09.97); original claims 1-28 replaced by new claims 1-14 (4 pages)]

1. In an anti-creep device for a suspension having a pair of trailing arms with a first end rotatably mounted to opposite sides of a trailer frame, an air spring disposed between each trailing arm and the trailer frame to resiliently resist the upward movement of the trailing arms with respect to the frame, and an axle S connected to the trailing arms, the axle having opposite ends adapted for mounting a wheel thereto, the anti-creep device comprising: a pair of support arms adapted to be mounted at opposite sides of the trailer frame for rotational movement between a retracted position and an extended position, the support arms in the extended position being adapted to abut the 0 suspension at the opposite sides of the trailer frame to prevent movement of the axle toward the trailer frame and thereby prevent trailer frame creep, the support arms in the retracted position being disengageable from the suspension so that the axle is free to move with respect to the frame; an actuator rod adapted to extend between the opposite sides of 5 the frame, the pair of support arms being fixedly attached to opposite ends of the actuator rod for rotational movement therewith; and an actuator operably connected to the rod and adapted to rotate the rod and thus the support arms between the retracted and extended positions; the improvement which comprises; 0 a support arm sensor adapted to be mounted to the frame in the vicinity of at least one of the support aπns for sensing the position of the at least one support arm; and an indicator operably connected to the sensor for indicating when the at least one support arm is in the extended position

2. An anti-creep device according to claim 1 wherein the actuator includes a housing that is adapted to be fixed with respect to the trailer frame and a shaft that reciprocates with respect to the housing; an outer end of the shaft being connected to the actuator rod for selectively moving the arms between the retracted and extended positions.

3. An anti-creep device according to claim 2 and further comprising a spring within the actuator housing for biasing the shaft outwardly of the housing to thereby bias the support arms toward the extended position.

4. An anti-creep device according to claim 3 wherein an inner end of the shaft includes a plunger and the housing is connected to a source of pressurized air to force the shaft inwardly of the housing against the bias of the spring when air pressure is applied to the plunger, to thereby rotate the support arms to the retracted position.

5. An anti-creep device according to claim 1 and further comprising a support member adapted to be secured at each end of the suspension in lateral alignment with each support arm, a lower portion of each support arm contacting the respective support member in the extended position.

6. An anti-creep device according to claim 5 wherein the lower portion of each support arm includes at least one notch for contacting the respective support member.

7. An anti-creep device according to claims 1 or 5 wherein the lower portion of each support arm includes a plurality of notches extending along the length thereof for selectively adjusting the height of the trailer frame with respect to the axle.

8. In a low-ride trailer having a suspension including a pair of trailing arms with a first end rotatably mounted to opposite sides of a trailer frame, an air spring disposed between each trailing arm and the trailer frame to resiliently resist the upward movement of the trailing arms with respect to the frame, and an axle connected to the trailing arms, the axle having opposite ends adapted for mounting wheels thereto; an air brake mounted to the axle, the air brake including a spring brake actuator for applying braking force to said wheels when air pressure is released from the spring brake actuator, an air pressure source for supplying air under pressure to the spring brake actuator, a support arm mounted to the trailer frame proximate to the axle for rotational movement between a retracted position and an extended position, the support arm in the extended position being adapted to abut a portion of the suspension to prevent movement of the axle with respect to the trailer frame and thereby prevent trailer frame creep, the support arm in the retracted position being disengaged from the suspension so that the axle is free to move with respect to the frame; and an actuator operably associated with the support arm for selectively rotating the support arm between the retracted and extended positions, the improvement which comprises; a pressure switch that is at least fluidly connected to the air brake and the actuator wherein the actuator rotates the support arm to the extended position when air under pressure is removed from the air brake.

9. A low-ride trailer according to claim 8 wherein the actuator comprises a housing that is fixed with respect to the trailer frame and a shaft that reciprocates with respect to the housing, an outer end of the shaft being operably connected to the support arm for controlling movement of the arm between the retracted and extended positions. CT/US97/05976

10. A low-ride trailer according to claim 9 wherem movement of the shaft is dependent on the presence or absence of air pressure in the actuator housing, and wherein the pressure switch comprises an air supply valve for supplying air under pressure to the air brake and actuator, and an air exhaust valve for releasing air under pressure from the air brake and actuator.

11. A low-ride trailer according to claim 10 wherein a spring is located within the actuator housing for biasing the shaft outward of the housing when air pressure is released from the spring brake actuator, to thereby bias the support arm toward the extended position.

12. A low-ride trailer according to claim 11 wherein an inner end of the shaft includes a plunger to force the shaft inwardly of the housing against the bias of the spring when air pressure is applied to the plunger, to thereby rotate the support arm to the retracted position.

13. A low-ride trailer according to claim 8 wherein the support arm includes a plurality of notches extending along the length thereof for selectively engaging a portion of the suspension to set the height of the trailer frame at a plurality of respective distances from the axle.

14. A low-ride trailer according to claim 8 and further comprising a support arm sensor mounted to the frame in the vicinity of the support arm for sensing the position of the support arm; and an indicator operably connected to the sensor for indicating when the support arm is in the extended position.