Improvements in Self-feeding Percussive Apparatus such as Rock Drills and the like.

摘要

9782. Mauss, W. April 24. Percussive drills. - Relates to self-feeding percussive apparatus of the type described in Specification 15,121/07, [Class 85, Mining &c.], in which the percussive engine is pressed forward in an encircling shell and is checked by liquid in front of the shell, and consists in placing the valve controlling the escape of liquid on a part of the apparatus external to the shell. A valve seating 14 with detachable seats 19 is secured by a clip 15 on a neck 4 extending from the front end of the percussive engine 2 through the front cap 5 of the shell 1. Rubber or like valves 22 carried by stirrup arms 23 hinged on a pin 24 are held to the seats by a rubber band 25. Blocks 26 on the stirrup arms 23 are forced apart by a camsurface 9 on the piston-rod 6 when the drill 7 cuts to a sufficient depth. The valves 22 are thus raised from their seats, liquid escapes from the chamber 12 through ports 13, 21, and the engine 2 is moved forward by pressure fluid acting at the rear. The blocks 26 have bevelled inner edges, and may be changed to vary the feeding-point. The stirrup 23 vibrates laterally with the piston-rod, the valves 22 being thus unaffected by vibration. Cup-leathers 3 on the engine 2 have between them a ring 31 with radial holes 32 connected to atmosphere by a port 34. If leakage occurs, the nature of the discharge indicates which of the two leathers is defective.