GB713356A - Improvements in or relating to undercarriage controllers for aircraft - Google Patents

Abstract

713,356. Valves. GLOSTER AIRCRAFT CO., Ltd., KEY, K. J., and EDMUNDS, I. Dec. 11, 1952 [Dec. 11, 1951] No. 28989/51. Class 135. [Also in Group XXXIII] A hydraulic undercarriage mechanism is controlled by a valve operated by a push button device through a remote mechanical connection. As shown in Fig. 1, an up button 12 and a down button 13 are adapted to rock a lever 14 connected to Bowden cable operating the control valve. The groove 27, also seen in Fig. 2, is adapted to receive a stop 31 urged into the groove by a spring 33 acting on a cup 32. This stop is electrically withdrawn when the airspeed increases above a certain value, or when the pressure on the undercarriage legs decreases to a certain value, and thus prevents premature raising of the undercarriage. In an emergency, the undercarriage may be raised by heavy pressure on the up button. Member 26 is held fast by the stop, but the shaft 22 of the up button may move through it, compressing a strong spring 30. The piston member 28 then moves away from member 26, and stop 35 is interposed by spring 36, retaining the buttons in the up position. Stop 35 may be released manually. In an alternative embodiment (Fig. 4) groove 27 is replaced by an L-shaped groove, the stop 44 engaging the base of the L, and preventing axial travel of the button. In emergency, the button is rotated against spring 49, until the stop enters the axial portion of the L.