GB169529A - Improvements in or relating to hoisting and transporting apparatus - Google Patents

Abstract

169,529. Rushen, P. C., (Bomborn, B.). June 29, 1920. Jib cranes ; overhead travellers. - Comprises driving and controlling mechanism for jib cranes, travelling crabs, and like appliances arranged to hoist and traverse a load, with special means for changing over from -hoisting to traversing and vice versa by fixing certain members of the driving-gear, one of which is a planetary member. The controlling means comprise the interlocking of the brake and a main circuit-closing switch with the hand-operated motor controller, with provision for automatic actuation of all these three members from an end-stop-gear controlled by the hoisting drum. Figs. 1 and 2 show one construction of driving gear applied to a crab which travels along an I-beam 1. The gearing is arranged to drive the travelling wheels 2 or the hoisting drum 15. To drive the drum, the toothed wheel 16 is held stationary and a compound spur drive is then obtained from the motor pinion 6 through three pairs of toothed wheels. To drive the travelling wheels, the wheel 16 is released and the wheel 10 is held stationary. The wheel 9 then rolls round the wheel 10 and so rotates the wheel 16 which drives the travelling wheels through spur-and-bevel gear. Two pairs of wheels 9, 7 may be mounted on opposite, sides of the wheel 16 to give a balanced drive. The fixing means for the members 16, 10 conveniently comprises toothed levers 23, 24 which are raised from their engaging positions against the action of springs, by cams on a hand-controlled shaft 28, but brake straps or the like may be used as the fixing means. Figs. 4 and 6 show a modified construction of driving gear together with controlling gear. Two pairs of wheels 9, 7 are mounted on the same side of the member 16 in this case, and the wheel 10 is provided with internal teeth. When the member 16 is fixed, the pinion 6 drives the lifting chain wheel 15 through three pairs of coupled spur wheels as before, while, when the wheel 10 is fixed, the member 16 rotates and drives the travelling wheels through a chain-wheel 30. The motor is controlled by cords connected to a handoperated pulley 41 which turns the brushes through 180‹. The rotation of pulley 41 from its mid-position to start the motor in either direction communicates a corresponding movement to a shaft 36 through the medium of an arm 38 and projecting pins 40, and thus rotates cams 37 to release spring contacts to close the motor circuit, and also rotates cams 35 to press downwardly on toggle levers and force spring brake arms out of contact with a brake drum 34 on the motor shaft. Provision is made for rotating the pulley 41 automatically to stop the motor and apply the brake at the end of the hoisting or traversing operations. This mechanism is shown applied to the hoisting gear. A chain wheel 58, Fig. 4, is driven from the shaft of the lifting chain-wheel so as to traverse a nut 59 on a screw. At the end of the run the nut rotates one of the members 61, 62 fixed on the shaft 49, which is connected to a second shaft 69 through a clutch 65. The shaft 69 is connected by a spur train to the wheel 42, Fig. 6, fixed to the pulley 41. The rotation of the pulley 27, Fig. 4, when changing over the driving gear from hoisting to traversing, causes a projection 68 to move a shaft axially to disengage the clutch 65 and disconnect the hoisting stop-gear during the traversing operation. Fig. 10 shows a further modified driving gear in which two members 72, 73 are held stationary alternatively. The motor shaft carries two pinions 70, 71. The actual drive for both hoisting and traversing is non-epicyclic in this case, but the loose member 72 or 73, as the case may be, rotates idly when the other gear is working. The application of the invention to a jib crane is illustrated, the traversing mechanism being adapted to move the crane bodily along a ground rail or for slueing. For this purpose the drum 15, Fig. 1, carries the hoisting rope and the member 16 is formed as a bevel wheel geared to the running wheel through two sets of bevel gear. By the additional of a fixed horizontal bevel wheel, this movement can be converted into a movement in a horizontal plane round the fixed bevel wheel for slueing. Similarly the gearing shown in Fig. 10 also can be adapted readily to jib cranes. A further modification of the apparatus shown in Figs. 4 and 6 is described, in which the gearing can be arranged to drive either a lifting chainwheel or a lifting drum without having to be disconnected. The motor and the gear casing form units in this case and can be moved apart to accommodate the drum or nearer to one another to accommodate the chain wheel. The substitution of a pinion for the chain wheel enables the drum to be driven.