Patent GB-623228-A (GB)
Title: Improvements relating to taking up slack in rope haulage systems
IPC: B66B5/12
Filed: 1947-02-21
Abstract: 623,228. Rope haulage systems. BAIRD, O., and LEES, D. M. Feb. 21, 1947, No. 5081. [Classes 78 (ii) and 78 (v)] A rope-haulage system has a slack-preventing device which comprises a tensioning device 7 which engages the rope 3 and is so urged that when the system is at rest any slack in the rope is taken up by automatic displacement of the tensioning device ; a retaining device 12, 13, 14 for holding the tensioning device against return from the displaced position ; and means 2a for initiating operation of the retaining device when the system comes to rest. Fig .1. The rope from lift 1 passes round pulleys 4, 5 and 5a and is fixed at 8. Pulleys 5 and 5a are carried respectively by hydraulic rams 6 and 9. When pressure fluid is passed into the hydraulic press 6 ram 6 together with pulley 5 is moved downwards so that lift 1 moves upwards. When the latter reaches the top, the fluid pressure in press 6 is released, and the lift descends under its own weight till it reaches the bottom where it strikes the lever 2a. Meanwhile, ram 9' is maintained under constant pressure but remains stationary so long as the cable is under moving tension. When the lift comes to rest at the bottom and ram 6 is then completely exhausted, the ram 9 is free to move with its pulleys 5a upwards until the rope tension reaches a predetermined value. Ram 9 is integral with pulley block 7 (which slides on rods 10) and with screw 11, so that the latter moves upwards through a hole in fixed plate 12. On the screw 11 is a nut 13 which accordingly moves up from its normal retaining position which is flush with plate 12. Fig. 3. When the lift 1 reaches the bottom cam surfaces 23 fixed on the lift engage a cam wheel 22 to operate a control cylinder 20 which controls two hydraulic pistons 16 which operate pawls 14 to rotate nut 13 till the latter descends till it is flush again with plate 12. The pulley 5a is thus maintained in the new higher position. An independent pawl 25 maintains the nut 13 and pulley block 7 in position whilst the lift goes up and comes down, and the operation is repeated when the lift has again reached the lowermost position. Fig. 4. Bogie 36 is driven along rails 37 by haulage rope 33 which passes round pulleys 34, 38, 5a, 39, 35 and is driven by winch 32 which is reciprocated by rack and pinion 31 operated by hydraulic press 30. Pulley 5a is mounted in pulley block 7 movable by press 9 and has nut and pawl mechanism 13, 14 as in Fig. 3. Bogie 36 reciprocates on rails 37 and at one or both ends of its path, trips trip lever 40 which causes press 9 to push up pulley 5a if the rope tension has stretched and pawls 14 to rotate nut 13 to secure the pulley 5a in its new raised position. Pulley 5a may be a multiple pulley and there may be two such pulleys, the separation of which effects the tensioning. Hydraulic pressure to ram 9 is admitted through a small hole so that block 7 will rise slowly should the rope break. An automatic signal may give warning when the block 7 is nearing its upper limit and a new rope is thus required. A concertina sleeve 26 and cap 27 protects against dirt.