Improvements in or relating to detent devices

摘要

1,017,829. Coupling mechanisms; shovelling machines. HYDRAULIC UNIT SPECIALTIES CO. Aug. 31, 1962 [April 30, 1962], No. 33523/62. Headings E1F and E2B. [Also in Division F2] A detent device for an operating member that is movable relative to a support comprises telescopic members 43, 47, the inner member 43 enclosing a spring-loaded cam member 45 (Fig. 3, not shown) engageable with detent means 44 positioned in recesses formed in the inner member 43, so that, to couple the members 43, 47 together, the detent means 44 are moved apart by the cam member 45 to engage grooves 48 of the outer member 47. The coupling mechanism is released by inward movement of the cable 64 of a Bowden cable to disengage the cam member 45 from the detent means 44 so that the telescopic members 43, 47 may slide freely. The detent device may be used to control co-operation of the valve system of an hydraulic system for controlling the raising and lowering of a shovel 7, as shown in Fig. 2, the detent devices controlling the positions of valve spools 29, 30. In this application, the cable 64 is connected to a bellcrank 68 slidable along a cam bar 69 as the shovel is raised or lowered, which upon abutting a projection 71 moves the cable to actuate a screw 65, thus uncoupling the members 43, 47. The valve spools are automatically returned to their neutral position by springs 41. In alternative embodiments, a centrally positioned member is either slidably or rotatably moved inwards to disengage the member 45 from the detent means 44. The member 45 may be constructed as a ball or alternatively it may be conical shaped.