anti blocking the back wheel of a plough chain practice, used especially in the mines.

摘要

1405128 Chain locks; self sustaining gear GEWERKSCHAFT EISENHUTTE WESTFALIA 2 Oct 1972 [30 Sept 1971] 45338/72 Heading B8B An assembly for stopping the chain of a chain driven mining machine, comprises a rigid body 10 and a pawl 23 detachably supported in a pivot bearing 22 formed integrally with the body 10, the pawl being selectively engageable with the chain wheel of the machine to facilitate tensioning operations on the chain. The body 10 comprises two cast sections butted together to form therebetween the bearing 22 and a pocket 27 for pivotally receiving a mounting piece 28 for leaf springs 29 urging the pawl 23 into chain wheel engagement. A pocket 27 and bearing 22 is formed at top and bottom of the housing 10 so that it may be used in two alternate positions. The spring may be held in an inoperative position by a pin and holes in the mounting piece 28 and a body lug 33, and the pawl may be similarly locked in the inoperative position. The pawl 23 has an integral pin 24 insertable into recesses of the bearing 22 and retained thereinby clamping sleeves. In use, the body 10 is bolted to the side of the machine frame and the machine drive drum bearing is housed in an opening 20 in the body, and the chain wheel is housed between the machine frame and an extension 15 of one of the cast sections of the body 10, this extension having an opening 16 through which the chain wheel can be inserted.