| 摘要 |
1,115,384. Ratchet clutches and brakes; dashpots. S.S.S. PATENTS Ltd. 24 Sept., 1965 [8 Oct., 1964], No. 41156/64. Headings F2C, F2E and F2S. In a synchronous selfshifting one-way clutch or brake, wherein an intermediate member 59 is helically movable along splines 57 on one clutch or brake member 54 to engage intermediate member teeth 60 with teeth 42 on the other clutch or brake member 41, the one member 54 is coupled to a rotary shaft or, as shown, a stationary member 45, through a lost - motion positive connection in parallel with a fluid dashpot means 50, the take-up of load after the teeth 60, 42 are fully engaged being cushioned by the dashpot means during relative circumferential, lost-motion taking-up, movement between the members 54, 45. Helical movement of the intermediate member 59 is initiated by a pawl and ratchet mechanism 43, 61 between the members 41, 59. In the one-way brake shown, the lost-motion connection comprises generally radial lugs 64, on the member 54, extending through circumferentially larger slots in a ring 44 fixed to the stationary member 45. The dashpot means 50 comprises one or more sets of co-operating pistons and cylinders respectively connected to the lugs 64 and the ring 44. The cylinders are supplied with oil under pressure through inlets 51. After full engagement of the teeth 60, 42, oil is expelled slowly through orifices in spring-biased valve plungers in the cylinders, bringing the member 41 to rest as the lost motion is completely taken up. On releasing- rotation of the member 41, the cylinders are recharged through ports opened by movement of the valve plungers against their springs. In the one-way clutch of Fig. 9 (not shown), the inlets 51 are connected by pipes to the rotating member of a rotary fluid union. In the one-way brake of Figs. 1-3 (not shown), the lost-motion connection comprises one or more pairs of axially extending, circumferentially widely spaced external and internal teeth respectively of said one brake member and the stationary member, and the dashpot means comprises the one or more circumferential chambers provided between said teeth. The axial ends of these external and internal teeth are respectively bounded by oil pressure inlet, spring-loaded, one-way valves and by exhaust orifices. The dashpot fluid restriction is provided by the external and internal tooth tip clearance. In Figs. 7, 8 (not shown), one or more cylindrical bags of flexible material, e.g. oil-resistant rubber, are provided between the widely spaced external and internal teeth and are supplied with oil under pressure through valves having spring-biased, orificed plungers. |
