GB517585A - Improvements in or relating to controlling devices for fluid pressure brakes - Google Patents

Abstract

517,585. Fluid-pressure brakes. BOSCH GES., R., (formerly BOSCH AKT.-GES., R.). July 30, 1938, No. 22737. Convention date, Aug. 2, 1937. [Class 103(i)] In a valve device for a fluid-pressure brake system comprising main and auxiliary valves suitable for the control of the brakes of a tractor and a trailer vehicle respectively and operated by a common lever the auxiliary valve casing is detachably secured to that of the main valve which is secured to the tractor vehicle or other support. The tractor valve body 10 is secured by bolts at 13 to the vehicle and the trailer valve body 16 is bolted to the body 10. The tractor valve comprises a pis'ton 31 with a tubular part 32 which is normally unseated from a supply valve 33 to connect the chamber 30, connected by passages 38 to the tractor - brake cylinders, to chamber 50, which is open to atmosphere. The trailer valve comprises a similar piston 31<1> carrying a tubular part 32<1>. normally urged by a tubular rod 42 under the action of a springs 40, to unseat the supply valve 33<1> to connect the trailer brake cylinder pipe 17 to the supply reservoir pipe 11 through passages 27; 27<1>. A floating lever 21 linked to the pedal 23, is connected by a lever 25 and push rod 19 to the piston 31 and to a rod 20 between which and the rod 42 is a spring 43. When the pedal is operated the rod ,42 is first moved to the left compressing spring 40 and permitting the piston 31<1> to close the supply valve 33<1>, the part 32<1> leaving the valve to allow the compressed air from pipe 17 to exhaust to atmosphere through the part 32<1> and passages 44, 45. When after the application of the trailer brakes has thus commenced, the pedal pressure becomes sufficient to move the piston 31 against the action of the spring 35 and the reservoir pressure on the valve 33 this valve is lifted by the tubular part 32 to supply the tractor cylinders. If the pedal is held in an intermediate position, the pistons 31, 31<1> due to the pressure increase and dedrease respectively acting on them are returned to a lap position in which both the valves are seated and the parts 32, 32<1> are seated on the valves. The lead in the operation of the trailer valve relatively to the tractor valve can be adjusted by varying the point of connection 22 of the pedal to the lever 21. When the trailer valve device 16 is detached, a component. 16<11>, Fig. 3, having a spring 43" and rod 20" for connection to the lever 21, is substituted, the spring acting in the same manner as the spring 43. The component blanks off the supply passage 27.