Patent GB-825541-A (GB)
Title: Improvements in or relating to heavy load carrying vehicles
IPC: B60P1/64
Filed: 1956-02-08
Abstract: 825,541. Spring suspensions; adjusting body height. RENDEL, H. A., and SCHAUER, R. L. Feb. 8, 1956 [Feb. 18, 1955], No. 3924/56. Class 108(2) A load carrying vehicle comprises a front section adapted to be motor driven and a rear section including a rear frame adapted for up and down movement relative to the front section while remaining substantially horizontal with respect to a transverse vertical plane, wheels at opposite sides of the rear frame, springs mounted for bodily displacement relative to the wheels and through which a portion of the rear frame imposed load is suppported by the wheels, means interconnecting the springs and the wheels for transmitting the portion of the rear frame load and interconnecting the rear frame and wheels for transmitting the remainder of the rear frame load to the wheels, and means operable to raise the rear frame including elevator means connected in rear frame supporting relation with the springs and means connecting the elevator means with the rear frame for raising the rear frame relative to the wheels, springs and elevator means in response to operation thereof while the springs remain under rear frame imposed load. As shown, a truck 20 includes a front section 21, Fig. 1, carrying a motor for driving front road wheels 28, and a rear section 22 carried on pairs of road wheels 43, 44 at each side thereof and connected to the front section 21 for adjustable sliding movement thereon. The rear section 22 includes a frame 32 having an upright section 33 which is supported in guiding relationship with a frame part of the front section 21. The road wheels at each side of the frame 32 are carried by swinging links 47, Fig. 7, each pivotally connected through a link 53 with one end of a leaf spring 52. A clamp 60, Fig. 8, straddles the spring 52 and a pin 70 pivotally connects the clamp 60 with a saddle 72. In the normal "travelling position" of the frame, the frame is supported on the saddle 72 through retractable pins 79, Fig. 8, carried by the frame. A bar 84 is welded to an outer leg 74 of the saddle 72 and pivotally carries a bar 86, to the ends of which are attached chains 88. The chains extend over sprockets 89 and are secured at their other ends to the frame 32. The sprockets 89 are journalled between a sleeve 92 and a bracket 95 secured thereto. The sleeve, and thus the frame, are raised and lowered by means of a fluid-pressure operated ram 96 attached to the sleeve 92 and operating a plunger within a cylinder 101 which is secured directly to the saddle 72. Preferably, the pins 79 are retracted simultaneously with the raising of the sleeve 92, so that if the sleeve 92 is subsequently lowered with the pins 79 retracted, the frame can be lowered to road level, the road wheels pivoting about the links 47. The fingers 79 are normally spring-biased to the extended position and are retractable by means of a pneumatically operated piston and cylinder 110, 114, Fig. 12, controlling a linkage 119, 123, 124, 126. Vertically extending channel irons 132, Fig. 14, attached to the front of the frame 32 slidingly engage channel irons 134 attached to a frame 30, Fig. 13, of the front section 21. The front end of frame 32 is raised by a hydraulic ram 142, Fig. 14, a cylinder 141 being attached to a main frame 29 of the front section. The ram 142 carries a saddle 144, Fig. 13, which supports sprockets 148 for chains 149 connected between the frame 30 and the front of frame 32. The frame 32 is lowered by a hyydraulic ram 156, Fig. 14, a cylinder 155 of which is attached to the frame 30. The ram 156 carries sprockets 158, Fig. 13, for chains 159 connected between the front frame 30 and the rear frame 32. Valve gear is provided to control the rams 142 and 156 which may be locked in a predetermined position. A hydraulic pump for the system is driven by the prime mover of the vehicle. Flexible piping for the hydraulic rams, the pneumatic cylinder 110 and the braking system for the rear wheels 43, 44 is carried on reels attached to the front frame 30.