Patent GB-255051-A (GB)
Title: Improvements in or relating to brake apparatus
IPC: B60T13/66
Filed: 1926-06-28
Abstract: 255,051. Jokel, J. July 9, 1925, [Convention date]. Fluid-pressure.-In a compressedair brake in which the brake may be put on and released in stages and the action of the brake is regulated in accordance with the load on the vehicle, the control valve has two pistons K<1>, K<11>, Fig. 1, or diaphragms, one face of which is under atmospheric pressure and the other under the pressure in the train pipe L and the brake cylinder Z respectively. The pistons K<1>K<11> act through a piston rod 1 and sleeve 6, and a lever 9 and the sleeve, to which the lever is pivoted at 7, against the substantially equal force of a spring F, or a weight or pressure piston, and the controlling member of the control-valve is actuated by these forces and a stiff spring f<11> and a weak spring f<1>, the three springs being so arranged to act on the piston rod 1 and sleeve 6 as to cause the required actuation of the control valve. The train pipe L is connected by a conduit a, through one part of a three-port regulating means H, and past ball and stop valves V<1>, V<11> to the auxiliary reservoir B, and through a conduit b to the ported slide face G of the control valve, which comprises also a slide valve S, co-operating with a stop o on the face G, and a jockey slide valve s co-operating with abutments m, n on the valve S, the ports being shown in Fig. 2 in release position. The valve s is con. nected by a link 14 to a lever 11 pivoted at 12 and to the sleeve 6 at 8, and the movements of the sleeve under the combined influence of the pistons K<1>, K<11> and the spring F, f<1>, f<11> actuates the valve s and, through the abutments m, n, the valve S. Small and large section conduits c, C lead from the valve face G respectively through another part of the regulating means H and directly to the brake cylinder Z, another conduit d leads from the valve face G through a third part of the regulating means H to the atmosphere, and a further conduit e leads to the conduit a between the valves V<1>, V<11>. The regulating means H comprises a throttle member h<1>, Fig. 10, and a conical regulating member h<11> concentric thereto. The member h<1> is non- rotatably connected to an arm 10 and to an arm 18 which may be set by hand or automatically in accordance with the load on the vehicle to vary the relative lengths of the two arms of the lever 9 which has an arcuate part with which the end of the arm 10 is in contact. The member h<11> has a handle which may be set in one of three positions, P for passenger train, G for goods train, and A an anti-operation position. The conduit a is fully open in positions P, G and closed in position A. The member h<11> has also small and large trapezoidal air inlets and outlets which cooperate with ports in the member h<1> so that the small inlets and outlets are in action for the position G and the. large inlets and outlets for the position P. When the pressure in the. train pipe is reduced, compressed air reaches the cylin_ der Z rapidly through both conduits c, C and from the reservoir B. Movement of the sleeve 6 causes the conduit C to be cut out, and the valves eventually assume the brake-on position with all conduits closed. Further reduction of pressure in the train pipe causes a further stage of brake, application and this procedure can be repeated until the pressure in the train pipe has reached its normal lower limit. Further reduction of pressure does not produce increased braking action owing to yielding of the spring f<11>. Increase of pressure in the train pipe causes movement of the valves to release the brake, by stages if desired, or the release may be effected directly by hand through wires connected at the arrows to a lever 16 pivoted at 17 and connected to the valve S. The valves s, S and face G are preferably semicircular with the ducts disposed in two rows. The spring F may be replaced by a piston in a cylinder connected to the conduit a by a, conduit with a non-return valve, an ordinary release valve being provided, or a weight may be employed. The Specification as open to inspection under Sect. 91 (3) (a) states also that the spring f<11> could be dispensed with if it is not necessary to guard against undue braking. This subject-matter does not appear in the Specification as accepted.