Position monitor for mine roof support units - supplies, collects and stores data indicating advancing movement of props.

摘要

The equipment is for ascertaining relative positions of a row of roof support units in underground mines. It includes a device on some of the support units which supplies data concerning advancing movement of the support units and their bases. The supplied data is collected and stored by a remote control store, and is recorded as deviations between an actual and a predetermined advancing movement of the support units. The data corresponds to the length of stroke of advancing cylinders located between face conveyor and the support units. Some of the support units are provided with a device which ensures that their advancing cylinder is activated before props of the support units supporting the face roof are lowered. The device consists of a switching arrangement between an electrically-activated magnetic valve of the advancing cylinder and an electrically-activated magnetic valve of the props.