GB251093A - Improvements in excavating machines - Google Patents

Abstract

251,093. Savage, W., Livens, F. H., and Ruston & Hornsby, Ltd. April 15, 1925. Scoop-arm machines. - In a scooparm excavating machine, a single or multiple bight in the hoisting cable is connected through a separate transmission to the scoop-arm, whereby the tension in the hoisting cable exerts a straight pull which the separate transmission converts into a thrust acting longitudinally of the scoop arm to move it outwardly. As shown in Fig. 1, the hoisting cable h passes over pulleys j, k in one or more bights and over pulleys l, m to a fixed point n; the pulleys k are carried by a rack o movable in guides 6 and engaging a pinion on the usual racking shaft r, whereby the pull in the hoisting cable tends to rotate the shaft r and force the bucket outwardly. Such motion is resisted when desired, or the bucket is returned, by means of an auxiliary cable p passing from a fixed point t over a pulley s on the rack and a pulley q on the shaft r to a drum f provided with driving connections and brakes. If desired, the cable p, suitably guided from the drum f, may be connected directly to to the lower part of the rack. In Fig. 2, the rack o is omitted and the pulleys k, guided if desired, are connected by a single or duplex cable v passing over a pulley w to one end of the scoop arm, while a single or duplex cable p passes over a similar pulley to the other end of the scoop arm. The pulleys j may be carried by a rearward extension of the jib and the cable h may pass from the pulley k over a further pulley at the top of the jib or direct to the pulley l. The cable p may pass over a drum on the shaft r or one geared therewith to act through the usual rack and pinion racking means, or a power-driven endless chain may be geared to the last-mentioned shaft. Specification 22685/02 is referred to.