GB375492A - Improvements in or relating to multi-armed grabs - Google Patents

Abstract

375,492. Grabs. ARDELTWERKE GES., Eberswalde, Berlin, and BERNHARD, J. M., Maising, Oberbayern, both in Germany. May 11, 1931, No. 13901. [Class 78 (iv).] In a grab of the kind comprising a plurality of grab-arms arranged star-wise and connected to the head of the grab by links, a sheave is provided on each arm and corresponding sheaves arranged in the head of the grab, the closing rope or ropes being passed alternately over the sheaves in the head and those on the arms, the said arms being free to move independently of one another. As shown in Fig. 1, the arms a, connected to the head c of the grab by links b, are provided with sheaves f, corresponding sheaves g being arranged in the head of the grab. The inward movement of the arms is limited by discs m, Fig. 2, which rest against one another and the outward and upward relative movements by chains n. Casings r mounted on guide links t pivoted at i on the links b, protect the sheaves f and the rope against damage caused by contact with the material being handled. Leaf springs i which are attached to the arms a so as to be in tension in the closed position of the grab assist the opening movement of the grab. Springs may be arranged on the pivots d connecting the arms a and links b so as to permit lateral movement of the arms relative to the links. In a modification, Fig. 6, the arms a are connected to the head of the grab by links p, q, in such a manner that the sheaves f move in an approximately vertical path.