Patent GB-191217254-A (GB)
Title: Improvements in and relating to Boat Launching and Stowing Apparatus.
Inventor: LEWKOWICZ ANTHONY JOSEPH
IPC: B63B23/04
Filed: 1912-07-24
Granted: 1913-06-12
Abstract: 17,254. Lewkowicz, A. J. March 19, [Convention date]. Boat raising and lowering gear.-Relates to apparatus described in Specification 13,695/11, in which davits 38, 39 carrying the lifting and lowering gear for the boats are mounted on athwartship curved tracks 3, and are moved thereon by worm - wheel mechanism operating driving - wheels 6. The hoisting - mechanism is enclosed in a water-tight casing 66 provided with water-strippers 41, 42. These strippers consist of a flexible metal tube 90 secured to the casing and terminate in bell-mouths 92<b> in which the grease from the falls collects and forms a water seal. Any water which gets into the casing is carried off by a trap 70 fitted with a non-return ball valve. The falls are wound on fall grooves 24, 25, Fig. 3, in a drum 19<a> mounted on a winding-shaft 20 journaled in the casing 66. The drum is formed with a braking-surface 21 engaged by the brake strap 23 having a brake shoe of end-grained oak blocks, leather or fibre. Adjoining this surface is a cylindrical part 19 having ratchet teeth 18 engaged by dogs 17 pivoted to the inner face of the worm-wheel 16 which is engaged by a worm 14 formed on a shaft 13 slidably mounted on bearings 102, 104 secured to the casing 66. This worm, which may be actuated by hand or other power, drives the drum when the boat is to be hoisted, but it is screwed out of gear when the drum runs out under the control of the brake. For this purpose, the shaft 13 is provided with a coniform worm 85 engaged by a lever 83 which, when the worm 14 is fully disengaged from the worm-wheel 15, drops over the end of the coniform worm and locks the shaft in its disengaged position. The ends of the brake straps 23 are secured to the arms 600, 610 of a bell-crank lever mounted on a shaft 58 so that by turning this shaft the pressure of the brake shoe on the brake surface can be adjusted. This turning-motion can be effected directly by means of a lever 55, Fig. 4, provided with a hand grip and locking - pawl. A more sensitive control is provided by a right and left handed screw 62 working in a fixed nut 64, Fig. 4, and in a nut 63 mounted in a yoke 61 pivoted to the lever 55. When bringing the boats inboard, the falls are sometimes slackened by the boat being raised on the crest of a wave, the slack is taken up independently of the ordinary winding-gear by turning a hand-wheel 88, Fig. 3, on the shaft 20 of the drum 19<a>, the ratchet teeth 18 allowing the drum to overrun the worm gear 14, 15. A single fall is used to lower the boat, the bight being threaded through the holes 24<a>, 25<a> on the drum, the ends after passing through pulley-blocks 33, 34, Fig. 1, hooked to the boats are attached to pulleyblocks 35, 50 hanging on the davits. This arrangement permits the respective lengths of the falls to be readily adjusted. To minimize the swinging of the boats when being hoisted &c., the davit falls are led obliquely from the blocks 35, 50 to the boat hooks 31, 32 which are fixed between the ends of the boat and its mid-ship section.