Pneumatic fastener-driving tool and method

Claim 2

Apparatus for effecting single-stroke driving of a fastener into a workpiece, said apparatus comprising: (a) a relatively light-weight, portable housing, (b) piston means movably mounted in said housing and associated with fastener-driver means for single-stroke driving of a fastener into a workpiece when said piston means is pneumatically actuated in a direction toward said workpiece, (c) means to deliver high-pressure air to the side of said piston means remote from said workpiece, to thus effect said pneumatic actuation, (d) reciprocator means movably mounted in said housing for movement in a direction away from said workpiece in response to said delivery of high-pressure air, and (e) means, operative when (1) said fastener has been substantially completely driven into said workpiece, and (2) said reciprocator means is moving in a direction away from said workpiece to provide a mechanical stopping relationsip between said piston means and said reciprocator means, said mechanical stopping relationship being such that said piston means, when at or near the bottom of its stroke and relatively adjacent said workpiece, provides at least a substantial degree of stopping action on said thus-moving reciprocator means.

Claim 3

The invention as claimed in claim 1, in which said reciprocator means is a hollow element which contains cylinder means, said cylinder means receiving said piston means (b).

Claim 4

The invention as claimed in claim 2, in which means are provided to create a fluid sealing relationship causing said reciprocator means to become a sealed vessel when said piston means is at or near the bottom of its stroke, thus preventing additional pneumatic propelling actuation of said reciprocator means in a direction away from said workpiece.

Claim 5

The invention as claimed in claim 3, in which combination bumper and sealing means are provided between said dimpler means and said reciprocator means, said combination bumper and sealing means performing the dual function of (1) causing said reciprocator means to become a sealed vessel, and (2) effecting said mechanical stopping relationship recited in clause (e) in the absence of excessive mechanical shock.

Claim 6

The invention as claimed in claim 4, in which said apparatus further comprises bumper means on the end of said dimpler means remote from said workpiece, and adapted to be engaged by said piston means with minimized shock.

Claim 7

The invention as claimed in claim 1 in which said reciprocator means is slidably mounted within said housing using low friction material so that there is a relatively small amount of transmission of kinetic force from said reciprocator means to said housing, while said reciprocator means moves in a direction away from said workpiece.

Claim 8

The invention as claimed in claim 6, in which the relationship between said reciprocator means and said housing is such that said reciprocator means is, during normal operation of the apparatus, positively stopped by a portion of said housing at the end of the travel of said reciprocator means in a direction away from said workpiece.

Claim 9

The invention as claimed in claim 6, in which the pneumatic relationship between said reciprocator means and said housing is such that there is only a small pneumatic impact between said reciprocator means and said housing during travel of said reciprocator means in a direction away from said workpiece.

Claim 10

The invention as claimed in claim 1, in which dimpler means are provided to form a dimple in the workpiece around said fastener, said dimpler means being disposed to be engaged by said piston means in order to effect said dimpling, said dimpler means having a portion that operates, when said dimpler means is at or near the bottom of its stroke, to aid in forming a fluid seal relationship between said piston and said reciprocator.

Claim 11

The invention as claimed in claim 1 in which the relationship between said reciprocator means and said housing is such that said reciprocator means is, during normal operation of the apparatus, positively stopped by a portion of said housing at the end of the travel of said reciprocator means in a direction away from said workpiece.

Claim 12

The invention as claimed in claim 10 in which the pneumatic relationship between said reciprocator means and said housing is such that there is only a small pnuematic impact between said reciprocator means and said housing during travel of said reciprocator means in a direction away from said workpiece.

Claim 13

A pneumatic hand tool for driving fasteners comprising: (a) a housing adapted to be grasped by an operator, said housing having a front portion with an outer end surface, a passage formed in said front portion and opening outwardly through said outer end surface, and a chamber formed in said housing, said chamber being positioned rearwardly of and communicating with said passage; (b) fastener-driving means mounted in said chamber for forward movement from a ready-to-fire position through a single driving stroke to drive a fastener placed in said passage outwardly therethrough into a workpiece against which said outer end surface is placed; (c) selectively operable means for utilizing a source of pressurized gas to actuate said fastener driving means through said driving stroke; and (d) recoil-controlling means, slidably mounted in said chamber and having forwardly positioned stop means, for cooperating with said fastener driving means during and subsequent to said driving stroke to substantially preclude rearward recoil of said housing during said driving stroke, whereby said outer end surface may be hand-held in contact with a workpiece during substantially the entirety of said driving stroke, and to significantly reduce rearward recoil of said housing subsequent to said driving stroke, a portion of said fastener-driving means being slidably received within said recoil-controlling means and captively retained therein by said stop means.

Claim 14

A pneumatic hand tool for driving fasteners comprising: (a) a housing adapted to be grasped by an operator, said housing having a front portion with an outer end surface, a passage formed in said front portion and opening outwardly through said outer end surface, and a chamber formed in said housing, said chamber being positioned rearwardly of and communicating with said passage; (b) fastener-driving means mounted in said chamber for forward movement from a ready-to-fire position through a single driving stroke to drive a fastener placed in said passage outwardly therethrough into a workpiece against which said outer end surface is placed; (c) selectively operable means for utilizing a source of pressurized gas to actuate said fastener driving means through said driving stroke; and (d) recoil-controlling means, slidably mounted in said chamber and having forwardly positioned stop means, for cooperating with said fastener driving means during and subsequent to said driving stroke to substantially preclude rearward recoil of said housing during said driving stroke, whereby said outer end surface may be hand-held in contact with a workpiece during substantially the entirety of said driving stroke, and to significantly reduce rearward recoil of said housing subsequent to said driving stroke, a portion of said fastener-driving means being slidably received within said recoil-controlling means and captively retained therein by said stop means.

Claim 15

The tool of claim 12 wherein the weight of said recoil-controlling means is substantially greater than the weight of said fastener-driving means.

Claim 16

The tool of claim 13 wherein the ratio of said weight of said recoil-controlling means to said weight of said fastener-driving means is approximately six to one.

Claim 17

The tool of claim 13 wherein the ratio of said weight of said recoil-controlling means to said weight of said fastener-driving means is approximately eight to one.

Claim 18

The tool of claim 12 wherein said recoil-controlling means comprises a unitary reciprocator assembly having an internal cylinder, said portion of said fastener driving means includes a piston mounted in said cylinder, said actuating means include means for injecting pressurized gas into said reciprocator assembly to drive said piston forwardly through said driving stroke and simultaneously reactively drive said reciprocator assembly rearwardly from a ready-to-fire position, and said stop means include a resilient bumper positioned to collide with said piston subsequent to said driving stroke and absorb recoil energy of said reciprotor assembly.

Claim 19

The tool of claim 12 further comprising means for pneumatically returning said fastener-driving means and said reciprocator assembly to ready-to-fire positions subsequent to said driving stroke.

Claim 20

The tool of claim 12 further comprising means responsive to said driving stroke of said fastener driving means for forming a dimple in a workpiece around a fastener driven from said tool into the workpiece.

Claim 21

The tool of claim 12 in which said portion of said fastener driving means is mounted for linear movement along an axis which is parallel to but laterally displaced from the axis of movement of said recoil-controlling means.

Claim 22

The tool of claim 12, further comprising means, including a collation, for feeding fasteners to said tool.