Fluid powered impact tool

Claim 1

In a fastener driving tool suitable for driving fasteners having a pointed tip portion and a headed portion which is larger in diameter than said tip portion and upon which said fasteners may be impacted to be driven tip first into a workpiece, said driving tool comprising: means defining (a) a hammer guideway which terminates in a fastener discharge opening and (b) a fastener-feeding opening in the side of said guideway, said guideway being so dimensioned and configured as to accommodate at all positions along said guideway between and including those of said fastener discharge opening and of said fastener-feeding opening all portions of a fastener to be driven; means for feeding fasteners one at a time through said fastener-feeding opening into said guideway, said means for feeding fasteners including a fastener-holding magazine alongside said guideway and communicating with said fastener-feeding opening; a hammer slidably disposed in said guideway for impacting fasteners disposed in said guideways and discharging said impacted fasteners from said tool via said fastener opening, said hammer being movable in said guideway between a first retracted position short of said fastener-feeding opening and a second extended position beyond said fastener-feeding opening; and means for reciprocating said hammer between said first and second positions; the improvement comprising a groove-defining cam surface which is disposed to one side of said guideway and situated between and distinct from said fastener-feeding opening and said fastener discharge opening, said groove being so dimensioned as to accept only a tip portion of said fastener, said cam surface being directed from said fastener-holding magazine toward said guideway and inclined with respect to said guideway so as to exert a camming action on the tip portions of said fasteners disposed in said guideway which tend to assume a canted position relative to said guideway when impacted by said hammer.