Patent GB-287841-A (GB)
Title: Improvements in motor controlling apparatus
IPC: B61K7/12
Filed: 1927-12-31
Abstract: 287,841. Westinghouse Brake & Saxby Signal Co., Ltd., (Assignees of Mickley, J. K.). March 26, 1927, [Convention date]. Arresting-grips or frictional apparatus on permanent way; fluid-pressure. - Motor controlling apparatus for controlling from a distant point a fluid-pressure motor for operating more particularly rail.- way brakes arranged on the track, comprises an electrically actuated valve for the control of fluid under pressure, provided with one or more pairs of energizing circuits the two circuits of each pair being both controlled by a selector and each controlled by a pressure responsive device, the circuits each including a unidirectional current carrying device. An electrically actuated valve for releasing fluid under pressure from the motor and another for supplying fluid to effect the reverse operation of the motor, are also provided, unidirectional current carrying devices being included in their circuits to enable one or other of these valves to be operated in accordance with the direction of the current supplied thereto through the selector. The fluid pressure motor comprises a piston and cylinder 14 adapted to operate track brakes 2 when supplied with pressure fluid through a valve 27 from a pipe 38. The brake is released by exhausting the fluid through a valve 30 and fluid is supplied to the reverse end of the cylinder through a valve 35. Fluid is exhausted from the reverse 'end of the cylinder through a valve 33. These valves are controlled by pistons 24, 29, 32 operated on by fluid pressure supplied by pipes 38, 22 and controlled by electromagnetically actuated pilot valves R, P, N. The circuits of these pilot valves are controlled by the manually operated selector H the circuit of valve R is also controlled by pressure responsive devices in the form of bourdon tubes D - - G communicating with the right hand end of the cylinder 14 and adapted to open contacts 7 successively as the pressure in the cylinder increases. An intermediate point in a battery 51 is connected to one terminal of each of the magnets of the valves R, P, N the other terminal of the magnet of the valve R is connected through the contacts 7 and unidirectional current devices 45 - - 48 to the selector H and the other terminals of the magnets of the valves P, N are connected through unidirectional current devices 49, 50 to the selector H. The operatively connected levers 8, 9 of the selector H are connected to the terminals of the battery 51. In applying the brake the lever 8 is moved on to contact 10<G> and a circuit for the magnet of the valve R is closed through the device 48 and a contact 7, the current cannot flow through the device 47 due to its polarity. The lever 9 is simultaneously moved onto a segment contact 11<P> closing a circuit through the magnet of the valve P, device 50 prevents flow of current to the magnet of the valve N. When the lever 8 is moved to a contact 10<F> the lever 9 is moved to a contact 11<F> and closes a circuit for the magnet of the valve R through the device 47 and a contact 7 adapted to open at a higher pressure, device 48 preventing the flow of this current, due to its polarity. Devices 45, 46 operate in a similar manner to the devices 47, 48. In releasing the brake the lever 8 is moved in the reverse direction to contact 10<N> and a circuit is closed for the magnet of the valve N through the device 50, the device 49 preventing flow of current to the magnet of the valve P, the circuit for this magnet having been broken when the lever 9 was moved from the contact 11<P>. In a modification two oppositely disposed unidirectional devices replace the devices 45 - - 48 and are arranged in branches of the wire 61 and connected to alternate members 7 respectively. The unidirectional devices may be of the type described in Specification 257,305, [Class 37, Electricity, Measuring &c.].