Patent GB-907927-A (GB)
Title: Improvements in or relating to suspension systems for trailer vehicles
IPC: B62D53/06
Filed: 1961-05-01
Abstract: 907,927. Adjusting wheelbase on trailer vehicles. FRUEHAUF TRAILER CO. May 1, 1961 [June 27, 1960], No. 15756/61. Class 108(2). An adjustable suspension system for a trailer vehicle having a wheel bogie and a trailer body comprises means normally restricting relative longitudinal movement between the bogie and the body, and means including anti-friction means operable concurrently to disengage the movement restricting means and to interpose the anti-friction means between the bogie and the body to facilitate relative movement therebetween. Fig. 3 is a view of the rear part of a trailer vehicle, the sides of the body 12 being provided with rails 54 co-operating with lift mechanisms 50, one located on each end of bolsters 26, 28, 30, which interconnect longitudinal frame members 22, 24. The road wheel axles 34 support the bolsters through springs 32 and brackets 31. Fig. 4 is a cross-section of one end of bolster 28, its lift mechanism 50, and one rail 54, Fig. 8, being a side elevation. The rail 54 normally rests in a way 150 formed in parts 158, 159 of a bracket 154 on the end of the bolster. Co-operating teeth 166, 168 on the bracket and rail are engaged, and prevent relative longitudinal movement between the bogie and body. Each lift mechanism comprises an arm 60 pivoted to the bolster at 63, and having a journal 68 for a roller 52 retained on the journal by an end plate 73, anti-friction means being disposed between the roller and arm 60. The end plate has an extension with a flange or gooseneck 128, which normally engages and clamps a similar flange or gooseneck 125 on rail 54. A pivot 84 in bolster 28 extends through a slot 86 in an arm 60, and supports a cam lever 80 having a cam face 95 engageable with a roller 96 on arm 60, and a cam face 100 engageable with cam surface 101 on arm 60. A pivot 105 on lever 80 is connected to the ram 106 of a pneumatic jack 108, and to a tension spring 111 anchored to an aperture 112 in arm 60. To move the bogie relatively to the body, the bogie brakes are applied, and jack 108 is connected to a pressure source, rotating lever 80 clockwise. Cam face 95 engages roller 96 to rotate arm 60 clockwise. This first disengages flanges 128, 125, and roller 52 then abuts rail 54, lifting the rail and body, and disengaging teeth 166, 168. The tractor vehicle can then be driven to move the body over the bogie, the rails running on the rollers 52. When actuator 108 is disconnected from the pressure source, it is contracted by spring 111, and cam lever 80 is rotated anti-clockwise. Arm 60 is pushed down by the weight of the body, and is locked down by surfaces 100, 101, which thus hold flange 128 clamped on flange 125. Teeth 166, 168 re-engage in a new relative position. In a modification, Figs. 9-13 (not shown), the roller is mounted on a journal eccentrically located on a shaft running through the bolster laterally of the body, and is raised by rotation of the shaft to lift the rails and disengage the teeth 166, 168. The clamping flange is operated manually through a toggle lever which can be locked in the over-dead centre clamping position by a pin.