| 摘要 |
<p>1,127,620. Hydraulic pit props with friction lock. K. GERLACH & H. GERLACH. 31 Dec., 1965 [31 Dec., 1964], No. 55353/65. Heading E1E. In a hydraulic pit prop having a friction clamp locking device 3 3 3', the plunger 2 is made up from two rolled sections which are welded to-gether and are provided with an inner or outer surface of oval or elliptical cross-section tapering in a direction away from the mine roof cap. The plunger slides about a guide member 4 having an inlet 6 for a pressure hose, movement of the plunger being limited in one direction by pegs 12 engaging the underside of the member 3.</p> |
