GB1461936A - Rereeving the cable of a hoisting gear - Google Patents

Abstract

1461936 Re-reeling hoisting gear cable LINDEN-ALIMAK AB 5 Feb 1974 [9 Feb 1973] 05330/74 Heading B8B Hoisting gear comprises a crane jib 1 along which an upper pulley block is movable on wheels 3, and a lifting cable 14 extends from a fixed anchorage 15 on the jib 1 about pulleys 5, 7 on the upper pulley block and then extends downwardly and passes about pulleys 10 and 9 on a lower hook block 13, the cable then extending upwardly and passing about pulleys 6, 8 on the upper pulley block to a pulley 29 from which it extends to a hoist machinery (not shown), the hoisting gear also including a cable catching device 18 which is releasably attached to the lower block 13, Fig. 3, the function of the device 18 being to pull one of the cable parts 26, 27, extending between the pulleys 6, 8 and 5, 7 respectively, on lowering of the pulley block 13 so that a loop providing two additional cable parts 16 or 17 is produced which is then transferred to one of the spare pulleys 11 or 12 on the block 13, or else to transfer such a loop from the block 13 back to the upper pulley block where it will extend straight between the pulleys 5, 7 or 6, 8, on raising of the block 13. The cable catching device 18, Fig. 3, comprises a pulley 21, rope rejecting stud 22, latch 23 which is actuated by a tension spring 24 and a pair of cable diverting guides 19, 20. Suppose that the lower block is suspended by only two cable parts from the upper pulley block and it is desired to increase to four cable parts. The cable catching device 18 is set in the position of Fig. 3 in which the latch 23 is in an inoperative condition and an opening 29 to the pulley 21 is open, and the block 13 is raised up to the upper block and as shown in Fig. 3 the cable part 26 enters the opening 29 and engages the pulley 21. On lowering the block 13 a loop is pulled down therewith by the device 18 and that loop is attached manually to one of the spare pulleys 11, 12. If two extra cable parts are required the cable part 27 is likewise drawn down by the device 18 and manually attached to the other pulley 11, 12. However, if the block 13 is already suspended by four cable parts and it is desired to re-reeve to two cable parts, the latch 23 is manually rotated about its shaft 25 to the position of Fig. 4 (not shown) in which the spring 25 biases the latch 23 against the side of the stud 22. The cable loop 16 or 17 is transferred from either of the pulleys 11, 12 to the pulley 21 in the device 18, and the lower block 13 is raised. The loop will then decrease until it is horizontal between the associated pulleys in the upper block, but upward movement of the block 13 and device 18 continues, so that as the cable part 26 leaves through the opening 29 it abuts against and rotates the stud 22 in an anti-clockwise direction until a shoulder on the stud 22 engages with a shoulder on the latch 23 and the stud 22 is then latched, as shown in Fig. 5 (not shown) and the opening 29 is closed, so that on downward return movement of the block 13 and device 18, one of the cable parts 26 or 27 cannot be caught by the device. Several cable catching devices can be used simultaneously for pulling down several cable parts from the upper pulley block.