Patent GB-294478-A (GB)
Title: Improvements in or relating to systems for transmitting movement, particularly brakes
IPC: B60T13/36
Filed: 1928-07-18
Abstract: 294,478. Monge, G. de. July 23, 1927, [Convention date]. Fluid-pressure; foot and personal actuation. - A system for transmitting movement particularly for automobile brakes comprises an auxiliary source of power acting by the throttling of a current of fluid produced by a needle valve adapted to be moved by a foot pedal against spring resistance the tension of which is influenced by the operated element and the cross sections of the needle valve and the orifice therefor are made so that the proportion between the spring tension and the pressure in the working chamber of the auxiliary source of power retains a practically constant value. The brake 4, Fig. 2, is operated by a direct connection 4m to the operating pedal lever 2 and also by a vacuum cylinder 3 or bellows controlled by the needle valve 6 connected at 76 to the lever 2. The valve penetrates an orifice 6t against the action of a return spring 6n. The cylinder 3 is connected to the induction pipe of the vehicle engine by a pipe 8a, and in one modification there is such a clearance 4j between the connection 4m and the lever 2 that the brakes are operated by the cylinder 3 alone. In the arrangement shown in Fig. 3, the effort exerted on the pedal is transmitted to the brakes by the direct connection 4m until the reaction in the transmission compresses the spring 6n and the valve is moved to throttle the current of air induced by the vehicle engine through the bellows 3 and the pipe 8a and the operated member 4 is moved and moves the lever 7 about the point 76. The apparatus is held by a spring 4r, Fig. 2, in release position, which is determined by a stop 4k acting on the brake pedal. This spring is of such a strength relative to the valve spring 6n that it turns the lever 2 to close the valve 6 slightly and create such a pressure in the cylinder 3 that a slight tension is produced in the transmission system, in the release position. Baffle plates 9k, Fig. 3, or expansion chambers, may be provided in the pipe 8a to reduce the flow of the current of air flowing through the apparatus, or the pipe 8a may be of small cross-section for this purpose. If the power means, lags behind the direct operation the consequent pressure produced in the bellows escapes by a spring-pressed valve 3p. The discs 3a, 3c at the end of the bellows are provided with projections 3q about which the bellows fold and which restrict the space therein. A modification is shown in which the pipe 8a is closed in release position by a disc carried on an extension of the rod of the valve 6. A groove is provided in the disc to maintain communication between the chamber 3 and the atmosphere. In a further construction, one member, which may be the rear brake of a motor vehicle, is operated by the direct connection and another which may be the front brakes is operated by the bellows 3. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a modification shown in Fig. 4 (Cancelled) in which the direct connection comprises a flexible link 4m passing over a pulley 6u supported on the slide-valve 6 which is moved against the pressure of a spring 6n by the tension in the connection 4m, on brake application, to cover the atmospheric port 6v and open the suction pipe 8<a> to the cylinder 3 by a groove 6g and a hollow 6j of the valve. This subject-matter is not contained in the Specification as accepted.