Patent GB-1043175-A (GB)
Title: Overhead travelling cranes
IPC: B63B27/12
Filed: 1963-08-02
Abstract: 1,043,175. Overhead travelling cranes on ships. MACGREGOR - COMARAIN. Aug. 2, 1963 [Aug. 16, 1962; Dec.,29, 1962; March 5, 1963; May 31, 1963; .July 8, 1963], No. 30741/63. Heading B8B. A ship 1, Fig. 1, has rails 7 on which run gantries 11 supporting telescopic beams 12, Fig. 3, and crabs 13. The gantries may be parked at the stern of the ship. Fig. 4, when not in use and in an alternative construction, Fig. 5. a section of rail 502a may be lowered and the gantries lowered to this level by a hoist 504. Each gantry 11, Fig. 6, supports a telescopic beam 12 by means of rollers 23 and guide rollers 22. The crab 13 runs on rollers 512. 513 on rails 26, 30 on the gantry and beam respectively. Pinions 516, 518 engage each other and racks 514, 515 to move the beam or the crab. The pinions 516 are moved up and down into and out of engagement with the rack 514 by levers 520 which also move pins 527 into locking engagement with holes 528 in the gantry 11. The crab supports winding gear 52 and a crab drive motor 46. Current is fed to the crab via a cable winder 69, Fig. 8, or the gantry and a winder 71 on the beam. A pin 74, Fig. 6, locks the beam to the gantry. Fig. 9 shows an arrangement in which the pinions driving the crab and the girder are constantly in mesh. Pinion 148 meshes with rack 149 on the beam 101 and a loose pinion 150 meshes with a rack 151 on the gantry 102. The pinion 150 may be caused to turn by a clutch 154 which is disengaged by an electromagnet 163. As shown in Fig. 10, a beam 101 may run inside a gantry 102 on rollers 185, 186 whilst the crab 103 runs on rollers 188, 189. The crab and beam are moved by a sprocket 195 and chain 197 which passes round the beam. To move the beam 101 to the left from the position shown in Fig, 17, the crab is first driven to the right-hand end by the sprocket 195 and locked to the beam in this position. Rotation of the sprocket 195 now causes the beam to move to the left, Fig. 20, extra chain being paid out from a tensioning device 202. Instead of using a telescopic beam the crab runway may be extended by providing hinged sections 167, Fig. 22. Alternatively, the sections may be hinged about vertical axes which may be slightly inclined to allow overlapping if the folding sections are more than half as long as the centre section. The longitudinal runways may be retracted by sliding each section down grooves in the supporting posts which may then be folded down. The racks 304, 305, Fig. 36a, on which the gantries run and discontinuous across the tops of the posts and to provide a continuous drive two pinions 306, 307 are provided so that one is always in a rack-engaging position. These pinions are resiliently mounted on their driving shafts to allow for the teeth on adjacent racks not registering exactly with each other. To obviate the case in which a pinion tooth meets a rack tooth end to end and causes jamming, an auxiliary sharp-toothed pinion 333, Fig. 42, is coupled to the driving pinion and engages a rack 326 provided with teeth 328, 329, 330 which ensure that this condition cannot arise. Fig. 44 shows a crab 407 which carries a motor 411 for moving it along the girder, but the winding gear 405 is on the gantry 403. Level movement of the load may be accomplished by synchronizing the travel and hoisting motors.