| 摘要 |
802,961. Davits. DAVIT DEVELOPMENTS, Ltd. Dec. 14, 1956 [Dec. 28, 1955], No. 37045/55. Class 115. A gravity davit has starter means including a rope, chain or other flexible power transmission operable to displace the davit arm or arms positively from the normally stowed position to overcome initial inertia or other obstruction to outboard movement of the arm(s) by gravity. In Fig. 1 the davit arm 1 has a hook 5 to which is attached a cable 2 which passes around a pulley 14 to a winch 3 having a winding handle 9. In Fig. 2, the cable 2 is attached to a lever 17 which is supported on a fixed pivot 18 and engages a roller 6 on the davit arm so that a pull on the cable turns the lever to position 17A causing the arm to move to position 1A and then falling by gravity to the fully luffed position 1B. Embodiments in which 2 sets in the manner of an endless cable are described. In Fig. 7 a davit normally housed on the ship's centre line has a cradle 19 with rollers 20, 21 engaging in tracks 15 which slope downwards towards the ship's side and are shaped so that when the cradle is drawn down the tracks by a pull on the cable 2, the davit approaches the position 1B, the cradle rocks about the rollers 21 and the rollers 20 rise up a cam-shaped part of the track. |
