Nonrotary piston for jackhammer and removable splined nut therefor
AssigneeIngersoll-Rand Company
InventorsPaul B. Campbell, Robert R. Kimberlin
Life of this patent
Estimating the term…
Abstract
A fluid-activated, percussive impact tool has a piston therein that reciprocates longitudinally but not rotationally. The piston activates a wrap spring clutch to rotate the drill steel. A removable splined nut in combination with the tool's housing restrains rotation of the piston, while permitting longitudinal reciprocation of the piston.
Claims9
In a fluid-activated percussive impact tool having a backhead at a top end, a drill steel chuck at a bottom end, a housing extending therebetween forming a central bore having a reciprocal piston therein, the improvement comprising:
- (a) said piston having a piston stem, a piston tail and a piston head therebetween;
- (b) means for supporting said piston for reciprocation along a longitudinal axis through said bore;
- (c) a plurality of longitudinal grooves extending along said piston stem and spaced apart around a circumference of said piston stem;
- (d) a plurality of helical grooves extending helically along said piston stem, each helical groove being spaced between a pair of longitudinal grooves;
- (e) interference fit means between said housing and said piston stem for permitting longitudinal reciprocation of said piston, while restraining rotation of said piston in said bore;
- (f) rotation means connected to said helical grooves for causing rotation, in one direction, of a drill steel positioned in said chuck during reciprocation of said piston;
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- (g) said interference fit means comprising a removable nut having a splined internal surface slidably connected to said longitudinal grooves and an external surface forming a male profile lobe thereon, said male profile lobe restrained from rotation by said housing at a female profile lobe cavity, said female profile lobe cavity formed to match said male profile lobe, said male profile lobe contacting said housing at said female profile lobe cavity in an interference fit to transmit torsional load from said piston to said male profile lobe and said female profile lobe cavity of said housing, whereby rotation of said nut and said piston is restrained, but longitudinal movement of said piston is permitted.
In a fluid-activated percussive impact tool having a backhead at a top end, a drill steel chuck at a bottom end, a housing extending therebetween forming a central bore having a reciprocal piston therein, the improvement comprising:
- (a) said piston having a piston stem, a piston tail and a piston head therebetween;
- (b) means for supporting said piston for reciprocation along a longitudinal axis through said bore;
- (c) a plurality of longitudinal grooves extending along said piston stem and spaced apart around a circumference of said piston stem;
- (d) a plurality of helical grooves extending helically along said piston stem, each helical groove being spaced between a pair of longitudinal grooves;
- (e) interference fit means between said housing and said piston stem for permitting longitudinal reciprocation of said piston, while restraining rotation of said piston in said bore;
- (f) rotation means connected to said helical grooves for causing rotation, in one direction, of a drill steel positioned in said chuck during reciprocation of said piston;
- and
- (g) a removable nut having a splined internal surface slidably connected to said longitudinal grooves and an external surface forming a male profile lobe thereon, said male profile lobe restrained from rotation by said housing at a female profile lobe cavity, said female profile lobe cavity formed to match said male profile lobe, said male profile lobe contacting said female profile lobe cavity in a first interference fit to transmit torsional load from said piston to said male profile lobe and said female profile lobe cavity;
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- (h) said nut having an apex formed on an external surface thereof, said apex contacting said housing in a second interference fit, whereby rotation of said nut and said piston is restrained but longitudinal movement of said piston is permitted.
Dependencies are inferred from the claim text.