Levelling system for vehicles

摘要

520,923. Tilting vehicle bodies to facilitate loading and unloading. DEHN, F. B. (Henney Motor Co.). Jan. 16, 1939, No. 1512. [Class 108 ( i) ] A vehicle body for a hearse, ambulance, taxicab &c. is adapted to be tilted by means of a frame elevating and depressing lever 42, connected to the frame 32 and to the wheel structure 34 by a link 44 on each side of the vehicle. Motor control means are provided to depress one lever and raise the other simultaneously to a desired angle from an intermediate position, the levers, however, being normally relatively freely movable to permit movement of the vehicle frame when not operated. As shown in Fig. 2 a bell-crank 42 pivoted on the frame is connected to a plate on the axle structure by a rod 44 and to a hydraulic cylinder 36 by a rod 40. A similar bell-crank is arranged on the other side of the vehicle and the two hydraulic cylinders are interconnected at the front and rear ends by pipes 45, 46, the front of each cylinder being connected by pipes 47, 48 to a pump casing 49, the pump being driven by an electric motor 53. The rods 40 are connected to double ended pistons in the cylinders 35, 36 and the oil leaking by these pistons is conducted by pipes 74 to a filter 75, and is returned through pipe 76 to the pump. The pipes 47, 48 enter a valve seat 87, Fig. 20, and are sealed by spring-pressed balls 971, 98' which project above the face. A rotary valve plate 50 covers the plate and is pressed into contact therewith by spring-pressed balls housed in the cover, these balls entering recesses in the rim of the valve plate 50 to hold it in the fixed position for tilting right and left. The central shaft of the valve plate projects outside the casing and is attached by a lever 51 to a rod 55, Fig. 2, operated by a control lever 54. When the control level is moved into the position for right hand levelling, Fig. 20, fluid pressure from pump enters port 86 and through registering hole 102 in plate 50 to back of plate and then through hole 103 in plate 50 and registering port 98 to unseat ball 981 and flows through pipe 48 into front end of cylinder 36 and rear end of cylinder 35. The fluid exhausted from front end of cylinder 35 and rear end of cylinder 36 flows through pipe 47 past ball 971 (which is depressed by plate 50) into channel 107 and orifice 99 to pump sump. If the motor stops the ball valve 98 is returned on its seat and maintains the pressure in the cylinders. The motor may be controlled by a press-button switch 56 and a mercury switch may be included in the circuit which breaks the circuit in the horizontal position. The lever 54 closes the circuit in the right or left position of tilting.