GB521375A - Improved means for locking a working piston actuated by a pressure fluid in a cylinder - Google Patents

Abstract

521,375. Hydraulic motors. JUNKERS FLUGZEUG - UND - MOTORENWERKE AKT GES. Nov. 17 1938. No. 33430. Convention date Nov. 26, 1937. [Class 69 (ii)] [Also in Group XXVI] A piston is locked within its cylinder at the ends of its stroke by means dependent upon inclined surfaces on the locking members. A piston 2 has end portions 6, 6<SP>1</SP> and a reduced body portion which carries a sleeve 3 having at its ends inclined surfaces 4, 4<SP>1</SP>. Between these surfaces and the piston ends are spring rings 5, 5<SP>1</SP> normally tending' to take the smallest diameter. When the piston arrives at one end of its stroke, the ring 5 lies on the inclined surface 4 and is expanded to enter a groove 7 in the cylinder wall. The end flanges 6, 6<SP>1</SP> are provided with a grooved passage 12 leading to inlet connections 11, 11<SP>1</SP>. To release the locking ring, pressure is admitted through 11 which moves the sleeve 3 relative to the body of the piston and so the ring 5 is able to contact and pass out of the groove. A spring ring 18 mounted in a groove in the piston body may co-operate with grooves 17 in the sleeve 3 to act as a locking means should the pressure fail. In a modification, the relatively slidable member is formed as a piston 23 in a hollow in the main piston 2, and the rings 5, 5<SP>1</SP> are operated by radial rods 16, 16<SP>1</SP> which are moved by the inclined surfaces on the central sleeve. This central member has a rod 29 passing outside the apparatus to contact points 31, 32 which are connected to an indicator showing when the locking means is engaged.