Explosive discharge actuated tool for driving fasteners

1. An explosive discharge actuated tool using a loaded cartridge for driving fasteners, comprising:

a barrel ( 16 ) having a bore ( 26 ) with a leading end ( 29 ) and a trailing end ( 27 ), the bore length being shorter than the barrel length, the bore ( 26 ) having an opening only at a firing chamber funnel ( 80 ) at the trailing end ( 27 ) of the bore and at a muzzle aperture ( 33 ) at the leading end ( 29 ) of the bore, the firing chamber funnel ( 30 ) covering the loaded cartridge in the firing chamber ( 44 ) prior to the cartridge exploding thereby directing the resulting force down the bore ( 26 );

a muzzle nose piece ( 28 ) having a predetermined length with a leading and trailing end, and a muzzle bore ( 31 ), extending from the trailing to leading end of the nose piece that is smaller in diameter than the diameter of the barrel bore ( 26 ), the trailing end of the muzzle nose piece ( 28 ) being attached to the forward end ( 22 ) of the barrel ( 16 );

a piston ( 82 ) with a leading end and a trailing end ( 83 ), sized to fit the barrel bore ( 26 ) and having a length that is less than the length of the barrel bore ( 26 );

a piston rod ( 84 ) having a leading and trailing end attached to the leading end of the piston ( 82 ) by the trailing end of the piston rod ( 84 ), the piston rod having a diameter sized to fit the muzzle bore ( 31 ) and a length selected to provide a predetermined distance between the leading end of the piston rod ( 84 ) and the leading end of the muzzle nose piece ( 28 ), when the piston ( 82 ) is in firing position; and

a spacer-fastener ( 118 ) having a length equal to the predetermined distance between the leading end of the piston rod ( 84 ) and the leading end of the muzzle nose piece ( 28 ), and a diameter sized to fit into the muzzle bore ( 31 );

whereby inserting the spacer-fastener ( 118 ) into the muzzle bore ( 31 ), after the tool has discharged, so that the spacer-fastener ( 118 ) does not extend beyond the leading end of the muzzle nose piece ( 28 ), moves the piston rod ( 84 ) and piston ( 82 ) into firing position with the trailing end of the piston ( 82 ) at the trailing end ( 83 ) of the barrel bore ( 26 ) and the trailing end of the spacer-fastener ( 118 ) and leading end of the piston rod ( 84 ) being in physical contact, before firing.

2. The tool of claim 1 wherein the muzzle nose piece ( 28 ) has a threaded trailing end ( 34 ) that is threaded into the forward end ( 22 ) of the barrel ( 16 ).

3. The tool of claim 1 wherein the firing chamber funnel ( 80 ) at the trailing end ( 27 ) of the barrel bore ( 26 ) directs all the explosive discharge into the barrel ( 26 ) at the trailing end ( 83 ) of the piston ( 82 ).

4. The tool of claim 1 wherein the muzzle nose piece ( 28 ) is interchangeable with different length muzzle nose pieces, as required to accommodate different length spacer-fasteners ( 118 ).

5. The tool of claim 1 wherein the spacer-fastener comprises:

a fastening nail ( 101 ) with a leading point ( 86 ) and a trailing head ( 105 ), the head ( 105 ) being in physical contact with the leading end ( 86 ) of the piston rod ( 84 ); and

a spacer ( 100 ) having a leading and trailing end, the leading point ( 86 ) of the fastening nail ( 101 ) being inserted into the trailing end of the spacer ( 100 ).

6. The tool of claim 5 wherein the spacer ( 100 ) is a cylinder with an aperture ( 111 ) in the cylinder wall and a split knob ( 109 ) at the leading end.

7. The tool of claim 6 further comprising a fastener clip ( 104 ) attached to the leading end of the spacer ( 100 ) by the split knob ( 109 ).

8. The tool of claim 1 wherein the leading end of the muzzle nose piece ( 28 ) is concave.

9. The tool of claim 8 wherein the spacer-fastener comprises:

a fastening nail ( 101 ) with a leading point ( 86 ) and a trailing head ( 105 ), the head ( 105 ) being in physical contact with the leading end ( 86 ) of the piston rod ( 84 ); and

a spacer ( 100 ) having a leading and a trailing end, the leading point ( 86 ) of the fastening nail ( 101 ) being inserted into the trailing end of the spacer ( 100 ).

10. The tool of claim 9 wherein the spacer ( 100 ) a cylinder with an aperture ( 111 ) in the cylinder wall and a split knob ( 109 ) at the leading end.

11. The tool of claim 10 further comprising a fastener clip ( 104 ) attached to the leading end of the spacer ( 100 ) by the split knob ( 109 ).

12. The tool of claim 11 wherein the fastener clip ( 104 ) has a convex surface ( 119 , 120 ) at the attachment to the spacer ( 100 ) that mates with the concave leading end of the muzzle nose piece ( 28 ).

13. The tool of claim 12 wherein the fastener clip ( 104 ) has an aperture ( 121 , 123 ) in the convex surface ( 119 , 120 ) with the split knob ( 109 ) passing through the aperture to attach the spacer ( 100 ) to the fastener clip ( 104 ).

14. The tool of claim 13 wherein the fastener clip is L-shaped with the convex surface on one leg of the L.

15. The tool of claim 10 wherein the cylindrical spacer ( 100 ) has a diameter that fits within the diameter of the muzzle bore ( 31 ) and the diameter of the split knob ( 109 ) is no greater than the diameter of the cylindrical spacer ( 100 ).

16. An explosive discharge actuated tool using a loaded cartridge for driving fasteners, comprising:

a barrel ( 16 ) having a bore ( 26 ) with a leading end ( 29 ) and a trailing end ( 27 ), the bore length being shorter than the barrel length, the bore ( 26 ) having an opening only at a firing chamber funnel ( 80 ) at the trailing end ( 27 ) of the bore and at a nozzle aperture ( 33 ) at the leading end ( 29 ) of the bore, the firing chamber funnel ( 30 ) covering the loaded cartridge in the firing chamber ( 44 ) prior to the cartridge exploding thereby directing the resulting force down the bore ( 26 );

a muzzle nose piece ( 28 ) having a predetermined length with a leading and trailing end, and a muzzle bore ( 31 ), extending from the trailing to leading end of the nose piece that is smaller in diameter than the diameter of the barrel bore ( 26 ), the trailing end of the muzzle nose piece ( 28 ) being attached to the forward end ( 22 ) of the barrel ( 16 );

a piston ( 82 ) with a leading end and trailing end ( 83 ), sized to fit the barrel bore ( 26 ) and having a length that is less than the length of the barrel bore ( 26 ); and

a piston rod ( 84 ) having a leading and trailing end attached to the leading end of the piston ( 82 ) by the trailing end of the piston rod ( 84 ), the piston rod having a diameter sized to fit the muzzle bore ( 31 ) and a length selected to provide a predetermined distance between the leading end of the piston rod ( 84 ) and the leading end of the muzzle nose piece ( 28 ), when the piston ( 82 ) is in firing position.

17. The tool of claim 16 wherein the muzzle nose piece ( 28 ) has a threaded trailing end ( 34 ) that is threaded into the forward end ( 22 ) of the barrel ( 16 ).

18. The tool of claim 16 wherein the firing chamber core ( 80 ) at the trailing end ( 27 ) of the barrel bore ( 26 ) directs all the explosive discharge into the barrel bore ( 26 ) at the trailing end ( 83 ) of the piston ( 82 ).

19. The tool of claim 16 wherein the muzzle nose piece ( 28 ) is interchangeable with different length muzzle nose pieces.