GB349571A

GB349571A - Grab for heapable goods

Info

Publication number: GB349571A
Application number: GB5811/30A
Authority: GB
Original assignee: NAAMLOOZE VENNOOTSCHAP HAVENBE
Current assignee: NAAMLOOZE VENNOOTSCHAP HAVENBE
Priority date: 1929-10-07
Filing date: 1930-02-21
Publication date: 1931-05-21

Abstract

349,571. Grabs. NAAMLOOZE VENNOOTSCHAP HAVENBEDRIJF VLAARDINGEN-OOST, Vlaardingen, Holland. Feb. 21, 1930, No. 5811. Convention date, Oct. 7, 1929. [Class 78 (iv).] In a grab of the type in which rods are hinged to the grab head and to the outer edges of the bucket jaws (as at f) and side-arms rigidly attached to the jaws are connected by a central hinge, the closing ropes q act on the side-arms at points v between the hinges f and the central hinge c in such a manner that when the grab is open the force exerted by the closing ropes on the side-arms has a large upward component but when the grab is closed this force has a large horizontal component. The rods e are hinged at i to toggle levers h, the joint k of which abuts against a stop on the grab head when the grab is open. The hinge f is slidable in a slot g to give the grab some additional span. Each closing rope q passes round a pulley p on the grab head, round one of the pulleys vl on one of the side-arms, over one of a number of pulleys l on the toggle joint k, round a pulley v<1> on the opposite side-arm, back over another pulley l, round another pulley v<1> on the first side-arm, and finally to one side of the equalizing member u pivoted to the grab head. Thus the pulleys l hold the closing ropes up inside the open grab so that they clear the material being grabbed and can exert an upward pull on the side-arms. When the grab closes the hinge c rises and the points v reach nearly the same level as the axle k, with the result that the sections x of the closing rope become nearly horizontal and most of the pull of the closing ropes is used to draw the side-arms together and keep the grab closed. The opening rope m passes from the rotatable crosshead r round one of the pulleys l. When the closed grab is suspended on the opening rope the toggle levers h exert a spreading action on the rods e thus initiating the opening of the grab. Owing to the large horizontal force exerted by the closing ropes on the side-arms of the closed grab it is possible, when hoisting the grab, to share the load between the closing and the opening ropes.