GB1078618A - Locking means for hydraulic control valves - Google Patents

Abstract

1,078,618. Remotely operated fastenings. HYDRAULIC UNIT SPECIALTIES CO. Aug. 3, 1965, No. 33159/65. Heading E2A. [Also in Division F2] In an interlock mechanism suitable for a manually operable valve of the "stacked" type (Fig. I not shown) the valve spool (8) whereof is displaceable in either direction from a neutral position to direct pressure fluid to a motor from an open centre passage (9), via a feeder passage (10) and a check valve (11), to either one of a pair of service passages (13 or 14) and exhaust fluid back to a passage (15), via a throttle (17) to an exhaust passage 16, the exhaust fluid, from passage (15) or other passage is connected at 42 to displace a piston 37, within cylinder 36 connected to the valve body 6, carrying a plunger 25 which is slidable against a spring 40 within an inner tubular extension 21 of cylinder 36 to force balls 23 into locking engagement with grooves 24 of an outer tubular member 22, connected to move with the spool 8, which grooves 24 may correspond to the operative displacements of the spool 8 from the neutral position, which movement may be regulated by a centering spring 44, or, with an additional intermediate groove (not shown), may also correspond to the neutral position of the valve. The lock is released when the pressure signal to 42 is terminated. The connection 42 may also be made to the exhaust or other fluid passage of a motor controlled by another valve in the stack to compel manipulation of the stack and valves in a predetermined sequence. The plunger 25 of the Fig. 2 embodiment may alternatively be actuated directly by a cable (63) (Fig. 6, not shown) displaced by a cam (65) carried by the motor load (60). The plunger (25) may alternatively be carried by the inner-tubular member (21') (Fig. 4 not shown) connected to the spool 8 and actuated by fluid supplied from the exhaust (15), via passages (52, 51) through the spool (8), to force the balls (23) into grooves (24) in the outer tubular member (22'), connected to the valve body, with either inward displacement of the plunger (25) by a spring (40) limited by abutment of a plunger head (54) with a shoulder (58) of the inner tubular member (21') or, with shoulder (58) omitted, a cam surface may be provided on the inward face of head (54) for engagement with balls (23) to provide a manually overridable detent mechanism. The plunger (25) may also be displaceable into operative locking position from the outer end of the inner spool (21") carried by the spool (8) (Fig. 7, by not shown) by a fluid motor (70), the piston whereof is displaced by a cam (65) with a manually overridable detent provided by a ball (72) loaded by a spring (73) into operation from the other side of the balls (23) to that of the plunger (25), or the ball (72) (Fig. 8 not shown) may be situated on the same side of balls (23) as the plunger (25) to provide the manually overridable detent mechanism when the ball (72) is not forced into locking engagement by the plunger (25).