GB912841A - Device for automatically detecting air pressure in a tyre and charging air thereinto - Google Patents

Abstract

912,841. Tyre-inflating plant. KABUSHIKI KAISHA SHINAGAWA SEISAKUSHO. Feb. 12, 1960 [July 8, 1959], No. 5016/60. Class 116. In a tyre-inflating plant comprising a compressed-air feed pipe F 2 with branches F 1 , F 3 , F 4 , leading respectively to the compressor C, pressure gauge P and to a vent, solenoid valves V 1 . . . V 3 in the branches are repeatedly opened in sequence, under the control of circuit control means operated by a synchronous motor, so that air is fed to or released from the tyre, the branch pipes are vented, and the pressure gauge is connected to the pipe, which sequence is repeated until the desired pressure set on the gauge is attained. The pressure gauge has a contact pointer P 1 , which gives a reading of the pressure, and a setting pointer P 2 which is pre-set to the desired pressure and which carries therewith limit contacts L, H, on each side thereof. The circuits of the valves V 1 . . . V 3 are controlled by relays MC 1 , MC 4 , MC 5 , which are under the control of switches DS 1 . . . DS 3 opened and closed in sequence by a drum switch actuated by a synchronous motor SM. Further switches DS 4 , DS 5 , on the drum switch serve to energize a lamp L and buzzer B when the tyre pressure reaches the pre-set value. When a tyre is connected to the line F 2 with main switch 5W 1 closed, valve V 3 is opened to operate the pressure gauge. Assuming the tyre pressure is below the pre-set value, pointer P 1 moves against contact L whereby the section 4. . . 6 of triode VG is energized and relay MC 5 is energized. When hand switch SW 2 on the air feed nozzle is closed, relay MC 1 is energized to close contacts 3, 2, and synchronous motor SM rotates to operate the drum switches DS 1 . . . DS 5 cyclically. Closing of switch DS 1 causes valve V 1 to be opened temporarily to supply a burst of air to the tyre; closing of DS 2 causes valve V 2 to open briefly to vent residual pressure from pipe F 2 , and closing of DS 3 opens valve V 3 to obtain a reading on the pressure gauge. This sequence continues until the tyre pressure rises to a value at which pointer P 1 reaches the pre-set value and moves away from contact L, when triode VG is de-energized to prevent further opening of the valves V 1 , V 2 . The switches DS 4 , DS 5 , now cause operation of holding relays MC 2 , MC 3 to put the alarm buzzer and lamp B, L 2 into operation. If the tyre pressure is above the pre-set value initially, the pointer P 1 rests against contact H and the relay MC 4 is energized so that the switches DS 1 . . . DS 3 cause venting of the pressure through valve V 2 until the pre-set pressure is reached.