GB516752A - Improvements in or relating to hydraulic remote control apparatus - Google Patents

Abstract

516,752. Hydraulic transmission with remote control. SPERRY PRODUCTS, INC. July 12, 1938, No. 20623. Convention date, July 31, 1937. [Class 69 (ii)] A balanced hydraulic remote control is arranged to maintain the parts in position after actuation and comprises a transmitter connected by a single column of liquid to a receiver and applying to the column a force which increases the further the operating means is actuated, the receiver offering increasing resistance substantially equal to the transmitter force. As shown, a lever 15, loaded by a spring 22, is pivoted at 17 and is so arranged that the force transmitted by an arm 18 to a piston rod 20 increases at a constant rate. The piston rod moves a piston 11 and thereby piston 11<1>, at the other end of liquid in a conduit C, is moved against the action of a spring 50. A valve stem 36 moves a valve 37 downwardly to open a port 38 to a source 39 of oil under pressure. The port leads to a propellor pitch control device to change the engine revolutions. As the engine " picks up " the valve closes the port to maintain the propeller pitch. For this purpose a governor 43 may be used. In a modification additional spring loading means may be employed for the piston 11<1> when it is desired to use a conduit C of such small bore that friction losses are relatively high. For periodically replenishing the liquid system trip mechanism 61 and reservoir 64 are employed as described in Specification 419,310.