| 摘要 |
334,561. Malet, H. R. March 7, 1929. Davits comprise a post 15 mounted on a foot step 16 and carrying a collar 20 in which is mounted a rotatable pillar 18 which supports a cantilever 21 constituting the davit proper and having on its upper surface rails 23 which, when the davit is moved by screw gear to its outboard position, align with similar rails on the head of the post 15. Wheeled trolleys 12<1> connected by a beam 12 run on the rails 23 and are moved along the rails by a chain 38 passing over inboard and outboard pulleys 39, 40 the former being operated by chain gear 43. The boat falls are led from inboard over the trolley to the lower fall block 9. In the event of the ship having a list, the davit structure, is tilted outboard, by screw gear comprising a block working on the vertically-mounted screw 28 and having pins 27 which work in a slot in the foot-step 16, the screw either being operated by power applied to the bevel wheel 29 or by the hand capstan 32. In an alternative construction, the pin or slot gear is replaced by a toothed sector on the footstool. In a further modification, the luffing of the davit is controlled by rope gear. The davit is elastically supported by the spring buffer 44 and the boats are mounted on wheeled trolley chocks &c. |
