GB290529A - Improvements in and relating to grab-buckets - Google Patents

Abstract

290,529. Voorwinde, W. Dec. 8, 1927. Grab-buckets.-A grabbucket adapted to reach under the coamings of a ship's hatchway comprises bucket members 6, 7 pivoted together or to parallel spindles at 8, connected by links 10, 13, and supported by an opening rope or ropes 15 and closing ropes 18, 19 arranged so that on paying out the latter, the grab descends relatively to the rope 15 and the buckets are opened by the links until the arms are substantially horizontal. As shown in Fig. 1, the rope 15 passes round a sheave 11 on the pivot pin 12 of the links and is secured to the grab at 45, and each closing rope 18, 19 passes round a guide sheave 20 or 22 and a sheave 16 or 17 on one bucket arm and is secured to the other arm at 23 or 21. When the rope 15 is held and the ropes 18, 19 payed out, the sheave 11 descends by the weight of the grab, and the point 45 descends at twice the rate so that the links 10, 13 are opened out. The gear is arranged within the bucket arms as shown, and separated from the spoil by partitions 24, 25. The edges of the scoops may be serrated. Bumpers may be provided on the casing of the sheaves 11 and on the pin 8. In a modification, Fig. 3 (not shown), the rope 15 is reeved to give triple purchase, the links 10, 13 are connected to the bucket arms nearer to the hinge pin, and the guide sheaves 20, 22 are carried on an equalizing lever on the pin 8. In Fig. 4 (not shown) two opening ropes pass round two pulleys 11 carried on an equalizing lever on the pin 12 and the arrangement is symmetrical, the links 10, 13 being of equal length. In Fig. 5 the rope 15 is reeved round sheaves 11, 20a, 11a and passes back to the hoisting gear. In Fig. 6, two ropes 15, 15a are connected at x, y to cams 29, 30 pivoted on the bucket arms at 31, 32 and connected by a link 33.