GB1216033A - An electric safety-box - Google Patents

Abstract

1,216,033. Control of motors; protective arrangements. NORD - AVIATION SOC. NATIONALE DE CONSTRUCTIONS AERONAUTIQUES. 2 April, 1969 [4 April, 1968], No. 17404/69. Headings H2J and H2K. The elevator system of an aircraft comprises a control column equipped with push-buttons 12, 13. A safety-box 14 controls the elevator surface by means of a motor associated with limit switches, and includes control relays 20, 21, and safety relays 22, 23. Operation of pushbutton 13, for example, causes relay 20 to close circuit 1, and opens the circuit 2 by energizing relay 23. An auxiliary box 15 comprises diodes 34-37 to prevent voltage-surges, indicators 32, 33 and diodes 38, 39 for looking the main circuits. When relay 20 is locked in the closed position button 13 is released to energize the safety relay 22 through a circuit starting from terminal 52, the indicator 32 being illuminated. Similarly, if relay 21 is locked in the closed position, button 12 is released to energize relay 23 through a circuit taken off at 62, the indicator 33 being illuminated. When button 13 is locked in the closed position, button 12 is depressed to energize relay 21 which energizes relay 22 through auxiliary contact 63 having taken the current from point 52. The indicator 32 is illuminated. If the button 12 is locked in the closed position, button 13 is depressed to energize relays 20, 23. If relays 20, 21 are locked in their closed positions, the circuits 1, 2 are opened by relays 22, 23, which are energized through auxiliary contacts 63, 64, both indicators being illuminated. When buttons 12, 13 are locked in the closed position, both indicators are illuminated. If in addition the relays 20, 21 are locked while closed, the safety relays are energized. When button 13 and relay 21 are locked in their closed positions, the circuits 1, 2 are opened and the indicators are illuminated. A similar result is obtained when button 12 and relay 20 are locked in their closed positions.