Patent GB-191228959-A (GB)
Title: Apparatus for Launching Ships' Boats.
Inventor: HEUREUX LUDGER L
IPC: B63B23/18
Filed: 1912-12-16
Granted: 1913-11-06
Abstract: 28,959. L'Heureux, L. Dec. 16. Boat raising, lowering, and disengaging gear. - Boats are lowered by a single swinging davit to which the boat is attached after being pushed into position on a travelling truck, the davit being governed in its rise or fall by a fluid-controlling device which automatically raises the davit when the lowered boat has been cast adrift. The davit 1, Figs. 1 and 9, is hinged at its lower end 2 near the water-line, and its upper end is forked at 3. The upper part of the davit is rotatable relatively to the lower part, being provided with a ball bearing swivel joint 7. This construction permits the davit with its boat being slued in and out while it may be locked in position by a catch 14. A carrier-plate 18, Fig. 7, is trunnioned to the forks 3 and is provided with a rotatable suspensionplate 23 which may be adjusted relatively to the carrier-plate 18 by operating a crank 32 which turns a pinion 31 gearing with a toothed annulus 22 on the carrier-plate. The boat, which is suspended by four chains 33, can thus be properly positioned to meet the waves before being lowered on to the water. The means for detaching the boat when waterborne comprise hooks 42, Fig. 5, working in brackets 40, 41 and engaging the shackles 34 on the ends of the chains 33. The hooks are connected by links 38 to draw-plates 37 and can be retracted when the boat is to be freed by turning a lever 36 on the transverse bar 35. The boats which run on rails 46 on the deck are run up to a point immediately below the davit where the deck is provided with a lowering-floor section 45, Fig. 4, which is normany held up by compressed-air cylinders 47 supplied from a pipe 50. By throwing over a lever 54, a three-way cock 53 is moved over to connect up the cylinders 47 with an exhaust pipe 52 whereupon the floorsection falls, leaving the boat hanging from the davit. A pitch chain 56 is provided with a trip block 58 which engages with a finger carried by the floor-section to turn the valve 53 to the 'off' position when the floor has risen to the proper height. In a modification, the floor-section is raised by telescopic air cylinders and arrangements are made whereby the deck section may raise boats from a lower deck to the launching-deck. The gear for controlling the rise and fall of the davit comprises a compressed-air cylinder 61, Fig. 3, in which works a piston 63 connected by a rod 64 to a horizontally-guided yoke 65. Ropes 72 connected to the davit are led around pulleys 70, 67 mounted on the bed-plate and the yoke respectively and are fastened at 73. The cylinder is connected up with a compressed air-supply through the pipes 78, 76, 75, 74 and when this supply is cut off, by operating a valve 80 which is linked with a valve 79 by a pitch-chain 88, the air exhausts through the pipes 78, 76, 77, 82, and the davit and boat are lowered to the water. When waterborne, a finger 90 on the yoke 65 is arranged to trip a stop-block 89, on the pitch-chain 88 and through the valve 79, a reducing-valve 83 and pipe 84 furnish the cylinder 61 with sufficient air to keep the boat constantly on the water with the chains 33 taut. When the boat is cast off, this power is sufficient to return the davit automatically to its raised position.