Patent GB-190718850-A (GB)
Title: Improved Means applicable for use in Dumping or Discharging Materials from Buckets.
Inventor: BARRY HERBERT ALFRED LUCAS
Filed: 1907-08-21
Granted: 1908-08-06
Abstract: 18,850. Barry, H. A. L. Aug. 21. Grabs.-Relates to apparatus of the kind described in Specification No. 15,416, A.D. 1900, [Abridgment Class Lifting &c.], for dumping and transferring grab or other buckets and comprises means for maintaining in tension the cables, for facilitating the employment of any desired multiple between the speeds at which the hoisting and traversing of the load are effected, for enabling a single chain for suspending and operating the grab or other bucket to be employed, and for preventing this chain from becoming twisted. The endless operating-rope A, Fig. 1, passes from the winding- apparatus C around a sheave a on the travelling carriage B and is maintained taut by a weighted pulley a<4>. The other operating-rope D is attached at one end to the carriage and passes to the winding- apparatus C. The other end is coiled around a drum d on the carriage and passes in the opposite direction to the winding-apparatus, being maintained in tension by a weighted pulley d. The pulley a is arranged to drive through bevel gear a wheel E. over which passes the hoisting-chain e. This chain carries the grab or other bucket, and is prevented from twisting on the chain wheel E by passing through a die e' on the carriage. The other end of the hoisting-chain is wound around a drum d<3> integral with the drum d and in the opposite direction to the rope D. The chain wheel E has formed on one face a spur-wheel e<4> engaged by a toothed segment b<1> having a pin b<2> adapted to throw off, during hoisting of the load, a pawl b<3> from a ratchet-wheel g formed on one face of a spring drum G, around which the tripping-rope of the bucket is wound. The pawl b<3> carries at its other end a weighted lever b<4> adapted to abut against a toothed wheel b<5> on one of the carriage axles. The lower end of the chain c carries a cross-head e<6>, from which is supported a spring-supported slide f<1> moving in a casing f <5> and to which the suspending- hook f is attached. Passing through the shackle of the hook f is a tripping-plunger f<2> having two pivoted arms f supported on stops f<4> and projecting through slots in the slide f<1>. From the tripping- rope g? is suspended a ring g<4> adapted to co-operate with the arms f <3>. In operation, the loaded skip is hoisted by a cable A rotating the chain wheel E through the sheave a and the gearing, the end of the chain being simultaneously wound on the drum e<3>. As the hoisting movement commences, the casing f<5> being caught up by the cross-head e<6> causes the arms f<3> to assume the position shown in Fig. 5, with the ring g<4> above them. During the hoisting operation, the pawl h<3> is held out of action by the segment b<1> and the rope g<1> is wound up simultaneously on the drum G until a collar g<2> abuts against the carriage. On further hoisting, the spring of the drum is wound up and the arms f<3> pass through and above the ring g<4>. The carriage is then traversed by the rope D. During lowering, the pawl b<3> drops but is prevented from engaging with its ratchet-wheel b<5> so that the rope g<1> and chain e descend simultaneously. By giving a small movement to the carriage by means of a lever c at the winding-apparatus, the lever b<4> is allowed to move into the position shown in dotted lines in Fig. 3, when the pawl b<3> drops into engagement with the ratchet-wheel g, and movement of the rope g<1> and ring g<4> is arrested. The descending arms f then engage the ring g<4> to send forward the plunger f to actuate the tripping-mechanism of the bucket, and the load is dumped.