Patent GB-189730924-A (GB)
Title: Improvements in and relating to Apparatus for Dumping, Depositing, or Releasing Loads Suspended from Cranes, Transporters, and other Hoisting-machines.
Inventor: TEMPERLEY JOHN RIDLEY
Filed: 1897-12-31
Granted: 1898-12-10
Abstract: 30,924. Temperley, J. R., and Temperley, J. Dec. 31. Grabs. - Relates to apparatus for tipping a suspended bucket or grab, through the medium of the lifting-rope, shown as applied to the travelling c r a n e described in Specification No. 14,720, A.D. 1897. The latch J, for liberating the bucket, is operated by a chain G<1>, which passes a r o u n d guidepulleys F<2> and is attached to a carriage G, which slides on rails f<2> and is fitted with a pawl K. This pawl is operated by the rotation of the pulley H in the fall-block, which is made with a peripheral recess H<1> for that purpose. When it is desired to tilt and discharge the bucket, the pawl having been previously cocked, the pulley H is rotated in the lifting direction to drive the carriage G on the rails f <2> to the left, thus raising the latch J through the medium of the chain G<1>. The pawl K is fixed to a shaft K<1>, Fig. 3, upon which is mounted a pinion K<2> engaging with a rack-bar L, which is normally forced to the right by a spring L<2>, but which, when fcrced to the left, is held in that position by a catch L<5> and spring-bar L<6>. The operation is as follows :-During the lifting operation, and the consequent rotation of the pulley H in the opposite direction to that indicated by the arrow, the shoulder H<3> simply strikes against and depresses the pawl K. When lowering commences, the shoulder H<2> strikes and carries the pawl into the position shown in Fig. 3, thus cocking it in the way described. When, therefore, the lifting motion is again started, the shoulder H<3> strikes the pawl and forces the carriage to the left, thus releasing and discharging the bucket. Disengagement is effected by a projection G<5> dropping through a gap in the rails f<2>, and also by a projection j, which forces the spring L<6> on one side and thus liberates the rack-bar L. The carriage is raised again, to bring it into action, by a lever M pivoted to the frame of the fall-block at M' and operated by striking against the bell p, or it may be by hand. The latch J is pivoted to a sliding-block J' with a projection with which a pawl J<4> on the block J<3> engages. As the block J<2> is raised, the block J' is carried with it, so that the latch J .disengages with the notched bar F<4> and drops into the recess in the bail. The following modifications are shown :- (1) The carriage G slides partly on one arm of a toggle-lever which, when lowered, disengages the pawl. The catch J is mounted on a radial arm and bears against the edge of the bucket. (2) The carriage G is dispensed with, the pawl K being mounted on a system of levers thrown into and out of action by the lever M. The catch J depends from the free end of a lever mounted on the top of the bail. (3) The tipping-mechanism is mounted on an auxiliary and independent sheave, to which also the tipping-chain G<1> is attached. Internal projections on the sheave H engage with the pawl. (4) The system of levers carrying the pawl is operated by internal projections on a weight capable of limited sliding motion on a bar, to opposite ends of which the lifting-chain and lifting- hook are connected. (5) A modification similar to the last is applied to the operation of grabs.