| 摘要 |
1,002,594. Fluid-pressure brakes. FABBRICA ITALIANA MAGNETI MARELLI S.p.A. July 18, 1962 [July 19, 1961], No. 27555/62. Headings F2E and F2F. [Also in Division H2] A compressed-air braking system for vehicles comprises two independent sections each supplying air via separate sections of a driver's valve to brake-operating devices which are common to both sections, the devices being adapted and arranged so that if one section fails the force exerted by the devices on the brake-applying members is unaltered, and an electro-pneumatic signalling device which signals to the driver the failure of either section of the system. As shown, an engine-driven compressor A supplies air to a pressurereducing valve B including check valves B1, B2 feeding separate sections of the system, each section comprising a reservoir C1 or C2 maintained charged by the compressor, a respective section of a two-section distributer control valve D operated by foot pedal F to determine braking pressure, and controlled-pressure lines G1, G2 each leading to front and rear sets of brake cylinders H, K. Each cylinder is of the kind disclosed in Specification 986,537, i.e. it is provided with two mechanically interconnected pistons defining two power chambers communicating with the respective lines G1, G2, the pistons being connected to a common link H1 or K1 for connection to the associated brake applying member, such that regardless of whether pressure is supplied to one, the other or both chambers the same force is produced to operate the brake applying member. The electro-pneumatic signalling device L is arranged to operate a warning device 36, e.g. a lamp, when failure in one of the sections occurs, and comprises a pair of cylinders 14, 15, Fig. 3, communicating respectively with lines G1, G2, and containing pistons 20, 21 acting via springs 18, 19 on opposite ends of a balance beam 24 rockable about pivot 26. In operation, unbalance between the pressures in lines G1, G2 causes rocking of a cam 30 supported by the beam 24 to close switch contacts 32, whereby the lamp is energised in either direction of unbalance. In a modification (Fig. 2, not shown) the front brake cylinders H are replaced by conventional cylinders having a single piston and connected only with the line G1, only the rear brake cylinders K being operable by both sections of the system. Specification 986,537 is referred to. |
