Patent GB-148344-A (GB)
Title: Improvements in and relating to cableway cranes
IPC: B66C21/00
Filed: 1920-07-09
Abstract: 148,344. Dittelbach, K. Dec. 30, 1918, [Convention date]. No Patent granted (Sealing fee not paid). Overhead travellers and transporters. - Travelling cranes for delivering material to any point over large areas such as slipways, are formed by fixing anchored rectangular bridge supports at each end of the area, and connecting them by pairs of tensioned supporting cables which are traversed longitudinally by one or more travelling bridges pivotally connected with the running trolleys on the supporting cables, the bridges being fitted with travelling crabs for lateral traversing. Figs. 1 and 4 show one arrangement in which a pair of carrying ropes 2 are stretched between supports 1 fitted with anchoring ropes 11. The bridge 3 is connected pivotally to a pair of running trolleys 6, one of which is fitted with a current collector 5 engaging an overhead conductor 4. A traversing rope or chain at each end of the bridge is connected to a fixed point on one support and is looped round a driven pulley 8 on the running trolley, thence passing to a hanging counterweight 10 on the other support. By declutching one of the simultaneously-driven pulleys 8 from the power gear, the bridge can be restored from a twisted position into its normal position at right angles to the ropes 2. The crabs are traversed along the bridge on rails as shown in Fig. 4. The Specification as open to inspection under Sect. 91 (3) (a) comprises also various modifications and detailed constructions as hereinafter described. In cases in which several bridges are employed, the running wheels may be of different gauge to engage different pairs of carrying ropes stretched between the same pair of supports. Alternatively, the pairs of carrying ropes may be all of the same gauge, and the bridges arranged on them in staggered relation. Fig. 10 (Cancelled) shows a particular construction of longitudinal traversing mechanism. The traversing cables of the bridge 17 are given several turns on the drums 25 and are stretched between the end supports by being connected to hanging weights as previously described. The drums 25 are connected by toothed gearing to shafts 26, 27 of which the latter is driven directly by a motor and the former through a combined clutch and brake 29 arranged so that when the clutch is operative, the brake is " off " and vice versa. During the traversing operation both shafts 26, 27, rotate simultaneously, but if the bridge gets twisted on the ropes, the clutch is released and the shaft 27 driven in the appropriate direction to correct the error. In order to prevent the twisting of the bridge from detaching the supporting wheels from the carrying-cables, the twisting movement may operate a cut-out switch on the end support of the bridge at the limit of safety and stop the motor. To damp swinging movements of the bridge set up by sudden starting and stopping, use is made of the particular form of suspension comprising pivot pins 18, Fig. 8 (Cancelled) connecting the running-wheel frames to the supporting-hangers. On the one hand, the drums.of the traversing-gear are arranged below the running-wheels so that oscillation of the bridge about the pivot moves them bodily against the resistance of the traversing cable; while on the other hand the supporting- frame is continued above the pivot and is connected to the upper half of a double plate spring 21. The lower half of the spring is fitted with oppositely-disposed gudgeon pins 22 working in elongated holes in crossed rods 23 mounted on the running-wheel frame. Oscillation of the bridge raises the gudgeon pins in one or other of the pairs of elongated holes, while the springs damp the movement. Hydraulic or pneumatic dash-pots may be used in lieu of the springs. This subject-matter does not appear in the Specification as accepted.