1655. Wilson, W. Nov. 21, 1912. Overwinding, preventing.-An apparatus for preventing the overwinding of pit cages comprises a block 0 moved to and fro bv the winding - engine and a weighted roller S supported on the block and arranged to fall by gravity, in the event of overwinding, to apply the brake and to cut off steam. The ends of the block 0 are sloping, and carry pivoted sectors P, P1 normally supported on catches V. When one of the catches V is released by engaging a standard W, the corresponding sector P falls unless an arm U, rigidly connected to the sector, is engaged and supported by a slide X. This slide is supported on a spring 9, and may be locked against vertical movement by a bolt Y. When a wind is started, with the parts in the position shown in Fig. 3, the block 0 moves to the left under the roller S, until the right-hand catch V is released by a standard similar to W. The roller S now runs down the inclined end of the block unless the engineman centres the reversing-lever. The centring of the reversing-lever causes the slide X to be locked, and prevents the arm U1 and the sector P' from falling. When the cage reaches the level, the roller S is at the extreme end of the sector, so that further winding, or starting the engine in the wrong direction, causes the roller to fall over the edge and arrests the engine. A projection, on the side of the block engages a tappet connected to the throttle valve for the purpose of cutting off steam at the required moment. The block O is driven to and fro by a pinion engaging a rack, the pinion being driven through worm and spur gearing from the winding-drum shaft.
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