Self-steering bogies for trailers

• US 3,899,188 A
• Filed: 02/11/1974
• Issued: 08/12/1975
• Est. Priority Date: 02/11/1974
• Status: Expired due to Term

• Current Assignee: Weldex Incorporated
• Original Assignee: Norman Royce Curry
• Inventors: Curry, Norman Royce
• Primary Examiner(s): Betts, Kenneth H.
• Assistant Examiner(s): Rubenstein, Jack D.
• Application Number:
  US05/441,119
• Time in Patent Office: 547 Days
• Field of Search: 280/81A,81B,8R,8B,103,81R
• US Class Current: 280/81.6
• CPC Class Codes: B60R 25/00 Fittings or systems for preventing or indicating unauthorised use or theft of vehicles locks for vehicles E05B77/00-E05B85/00
• CPC Class Codes: B62D 13/04 for individually-pivoted wheels

Abstract

A self-steering bogie for a trailer has a frame with at least one fixed rear axle and with a front axle having, at its ends, steerable stub axles connected to the front axle by forwardly located king pins. Above the frame is an intermediate slide that can be adjusted longitudinally along the underside of the trailer. Fixed to the slide is a first swivel, consisting of a vertical shaft on which said frame is journalled. Cranks extend from either side of the shaft below the frame, and links extend forwardly from said cranks along the underside of the frame to cranks of a second swivel having a vertical shaft journalled on the bogie near the front axle. Track rods extend from another crank of the second swivel to steering cranks on the stub axles.

Claims

1. A self-steering bogie for a trailer, comprising a member rigidly securable at the underside of the trailer to move therewith as the trailer rounds a curve, a bogie frame that can turn at the underside of the frame about a swivel axis, a shaft on said swivel axis, said shaft being fixed against rotation relatively to said rigidly securable member and extending downwardly therefrom through said bogie frame, first crank means rigidly connected to said downwardly extending shaft, a rear axle beneath the rear of the bogie frame, a front axle parallel to said rear axle and beneath the front of the bogie frame, an equalizing suspension system connecting the front and rear axles to the bogie frame, rear wheels supporting said rear axle, front wheels, a steerable assembly supporting said front axle on said front wheels, said steerable assembly including stub axles carrying said front wheels, king pins connecting said stub axles to the ends of said front axle for steering movements relative thereto, track rod means interconnecting the stub axles to maintain a predetermined relationship between their steering movements about the king pins, and drag link means connecting said first crank means and said steerable assembly, and second crank means pivotably connected to the front axle and operatively connected to the track rod means and drag link means to transmit steering movements from said first crank means to said steerable assembly.

2. A self-steering bogie as claimed in claim 1, wherein the steering movement transmission means comprises a relay member journalled on the front axle, said second crank means comprising first and second crank means on said relay member, and the link means connect the crank means on the shaft to the first crank means on the relay member, the second crank means on the relay member being connected to the track rod means.

3. A self-steering bogie according to claim 2, wherein the crank means on the shaft on the swivel axes and the first crank means on the relay member comprise pairs of crank arms extending to opposite sides of the shaft and the relay member respectively, the link means comprise links connecting the crank arms on each side of the shaft to the crank arms on corresponding sides of the relay member, and the track rod means comprise track rods extending from said second crank means on the relay member to the stub axles, the stub axles having steering cranks to which the track rods are connected.

4. A self-steering bogie as claimed in claim 2, wherein the track rods and drag links are connected by universal joints to the crank arms.

5. A self-steering bogie as claimed in claim 4, wherein the track rods and drag links are of adjustable lengths.

6. A self-steering bogie as claimed in claim 2, wherein the links have resilient means that can accommodate length wise adjustment of the links when the front wheels are deflected upwardly.

7. A self-steering bogie as claimed in claim 1, wherein the rigidly securable member is an intermediate slide beneath which the boGie frame is turnable, the slide being adjustable longitudinally along the underside of the trailer.

8. A self-steering bogie as claimed in claim 7, wherein the intermediate slide has means for limiting the angle through which the bogie frame can turn at the underside of the trailer.

9. A self-steering bogie as claimed in claim 7, including means for fixing the frame to the slide when aligned longitudinally therewith to facilitate backing the trailer.

10. A self-steering bogie as claimed in claim 7, including means for locking the frame out of longitudinal alignment with the slide to inhibit theft of the trailer.

11. A self-steering bogie as claimed in claim 1, wherein the king pins are located ahead of the longitudinal center line of the front axle, causing the wheels to urge the stub axles towards alignment with each other as the bogie moves.

12. A self-steering bogie as claimed in claim 1 in combination with a trailer at the underside of which the rigidly securable member is secured.

13. A trailer and a self-steering bogie therefore, the bogie comprising a first vertical shaft secured at the underside of the trailer, at the rear of the trailer, to turn therewith as the trailer rounds a curve, a frame journalled on the first shaft, the frame having at least one rear axle with wheels thereon, a front axle having at its ends stub axles with wheels thereon, and an equalizing suspension system connecting the front and rear axles to the frame, the stub axles having steering cranks and being connected by king pins to the front axle so as to be steerable, a relay member formed by a second vertical shaft journalled on the front axle, a pair of links extending longitudinally along the underside of the frame and connected by universal joints to cranks extending from opposite sides of the vertical shafts and rigidly connected thereto, and a pair of track rods connected by universal joints to a crank arm on the second vertical shaft and extending to the steering cranks on the stub axles.