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US 3,991,835 AGranted
Pneumatic rock drill with peripheral piston clearance space
AssigneeJoy Manufacturing Company
InventorsEdward A. Bailey, Walter D. Fish
Life of this patent
Estimating the term…
Abstract
A fluid operated reciprocating piston rock drill wherein the piston has a stem portion closely slidably received in a guide bushing and the cylinder of the rock drill provides clearance space around the head of the piston.
Claims5
A pneumatic rock drill assembly comprising:
- a rock drill body member adapted to carry a striking bar;
- a bore within said body member;
- a stepped piston member coaxially received and reciprocable within said bore and adapted to impact on such a striking bar;
- said piston member including a stem portion received within a reduced diameter portion of said bore and a head portion received within a larger diameter portion of said bore;
- said head portion having the exterior axial extent thereof of a diameter smaller than the diameter of said larger diameter portion to define a continuous open peripheral space between said head portion and said larger diameter portion of said bore;
- said stem portion being closely slidably received within said reduced diameter portion to maintain said peripheral space throughout the reciprocation of said piston member;
- and passageway means in at least one of said members operable to direct pneumatic pressure fluid alternately to said opposed faces to reciprocate said piston member.
4 more elements
Dependencies are inferred from the claim text.