| 摘要 |
1508912 Hoists B E WALLACE PRODUCTS CORP 19 March 1975 [22 March 1974] 11492/75 Heading B8B A winch hoist comprises a cable drum 11, rotatably driven by a manually oscillatable lever 13 and a pawl and ratchet mechanism 14, one end of the cable 15 being releasably secured to the drum whilst the other end of the cable carries a hook 42 which either directly supports a load in a single rigging condition of the hoist, or is hooked on to an eye L on the main frame 10 of the hoist to form a loop in the cable 15 which supports a pully block 43 carrying a load hook 41, in a double rigging condition. The drum end of the cable is anchored thereto by passing it through two axially spaced passages in the drum hub, the cable being seated in a helical groove on the hub surface between the passages, and the cable in each passage being locked by a screw in the hub. A land on the drum hub adjacent each passage maintains radial continuity of the first layer of cable on the drum. The handle H for operating the lever 13 of the pawl and ratchet mechanism 14 has a projecting link for spring detent engagement in any one of four angularly spaced radial sockets on a boss 22 of the lever 13, the link having a reduced section to permit bending of the link upon exerting a leverage above a pre-determined value. One flange 23 of the drum 11 carries a ratchet wheel 26 which is selectively engaged by a pawl of the mechanism 14 depending on the setting of a cocking lever 35. A holding pawl mounted on an axle 31 is spring biased against the wheel 26, but is disengaged due to abutment by the lever 13 when it reaches an adjacent position. Depression of a finger lever 37 also releases the holding pawl for free wheeling of the drum. |
