GB199290A - Improvements in or relating to overhead travelling cranes - Google Patents

Abstract

199,290. Rapier, C. V. Aug. 21, 1922. Adjusting and conneoting bogies for steering. - Relates to overhead travelling cranes comprising two trollies or groups of coupled trollies, each carrying one end of a girder forming a runway for a load trolly, the cranes being capable of moving on straight or curved tracks with junctions and crossings, with the trollies on parallel tracks or on a single track. In order to control the movement of the trollies at track junctions without movable switches, a hand-actuated device is provided at each end of the crane acting on guide mechanism on the trollies and the two devices are mechanically connected so that the crane may be controlled from either end. Fig. 1 shows one form of guiding mechanism applied to a crane comprising a beam 3 for the load trolly 14, supported at each end by coupled trollies 1, 2, running on a bi-rail track 4, the girder 3 being free to swing in any direction on the universal joint 8, 9. Sprocket wheels 15 at each end of the crane are connected by an endless chain and are turned bv hand from either end of the crane by a chain 16 which hangs within reach of the operator. Each sprocket 15 carries a U-shaped bar 17 with spring abutment at each end bearing against one side or the other of lugs 20 on the trollies so as to urge the trollies to one side of the track when approaching a junction. In a modification, the sprockets 15 extend tension springs which form the couplings between the trollies 1, 2, the springs being connected to the trollies so as to turn each of them about its pivot in the same direction. In another form, Fig. 9, by pulling on the fall 41 of a hand-chain at either end of the crane, a cable 36 is caused to dapress levers and raise rollers 30 at both ends of the crane into the path of cams 32 which are flxed above the tracks at the junctions. This device may be arranged, with or without stop mechanism, so that either or both of the rollers 30 may be raised at will, for guiding the crane from a single track to a single-track branch or to parallel branches bridged by the crane. In a modification, the rollers 30 are raised by levers actuated by cams fixed to sprocket-wheels such as 15, Fig. 1. In another form, shown in plan in Fig. 15, the trollies 1, 2 have side arms 66, 67 connected together by links and a lever 68 pivoting on the bolt 7 by which the beam 3 is suspended. Sprocket wheels such as 15, Fig. 1, each carry an arm 70 which bears against the lever 68 so as to turn the trollies 1, 2 in the desired direction. Corresponding arrangements are also described as applied to a crane in which the rollers of the trollies 1, 2 run on the flanges at either side of an I-beam forming a mono-rail track. In the modifications in which the rollers 30 are employed, the cams 32 may be arranged near the bottom edge of the track. In one form two single trollies of the bi-rail type 74, 75, Figs. 34 and 35, or in a modification two single trollies of the mono-rail type, are provided with an elastic guiding connection consisting of an endless helical spring 79 engaging with suitable teeth in sprockets 77. Either sprocket may be actuated by a hand-chain 21, and either or both trollies guided through a junction. In an arrangement with four coupled trollies of the bi-rail type, guiding rollers such as 30 are provided on the first and last trollies and are actuated through lever mechanism from hand-chains on the beam 3.