GB357520A - Improvements in or relating to the regulation of brakes - Google Patents

Abstract

357,520. Fluid-pressure brakes. MONGE, C. DE, 123, Boulevard de la Sauveniere, Liege, Belgium. May 22, 1930, No. 15812. Convention date, March 1. [Class 103 (i).] In a control device for brakes operated by the suction in the induction pipe of an internal-combustion engine, a chamber that is connected to the suction pipe under valve control and to the brake cylinder is connected also to the atmosphere through a passage which is of constant crosssection during the graduation of the braking action. This passage may however be closed when a quick application of the brakes is desired and it may be increased to effect a quick release of the brakes. As shown in Fig. 4, the casing of the control device is connected to the atmosphere, the suction pipe and the brake cylinder by the pipes 2d, 2c, 4 respectively. The valve rod 7a slidable in the casing carries a valve 6 which normally closes the suction pipe 2c and in this position a wide passage is open for the connection of the brake cylinder with the atmosphere. When the valve rod is moved to the right and the valve 6 is opened a collar 5d enters the air passage 3d, which is thus restricted and maintained of constant cross-section during the opening movement of the valve. The valve is of parabolic section so that the cross-section of the passage which it opens increases at first slowly and then quickly whereby the degree of vacuum obtained in the brake cylinder is substantially proportional to the movement of the valve rod and also to the compression of the returning spring 5m. This device may as shown in Fig. 5 be interposed between the brake pedal 15 and the lever 11 connected to the brake piston 3m and to the brake operating shaft 11b, the casing 8a of the device being connected to the pedal and the valve rod 7a to the lever. The release spring 11a is sufficiently strong to bold the valve rod normally in position against the action of the spring 5m with the collar 5d within the passage 3d. The pressure applied to the pedal in applying the brakes is transmitted through the spring 5m direct to the brakes and after the valve 6 has been fully opened the part 7b seats on the part 8 to close the air passage and also provides positive engagement between the pedal and the brake lever 11. If the pedal is released the spring 5m is able at first to move the collar 5d outside the passage 3d so that a quick release of the brake is obtained. In another construction the air passage is provided by an annular plug through which the valve rod passes and which is provided with baffles or deflectors which have a restricting effect when the intensity of the air flow increases. A slide valve is provided in this case, the suction port controlled by it being so shaped as to give a rapidly increasing opening.