Portable screw driving tool with collapsible front end

1. A portable fastener-driving tool, comprising:

(a) an elongated housing containing a prime mover device, said housing having a first end and a second end; (b) a first member extending from said first end of the housing, said first member having a third end and a fourth end, in a first, non-actuated state said third end being distal from said first end of the housing and said fourth end being proximal to said first end of the housing; (c) a second member extending from said third end of the first member, said second member having a fifth end and a sixth end, in said first, non-actuated state said fifth end being distal from said third end of the first member and said sixth end being proximal to said third end of the first member; (d) an intermediate drive device that extends between said prime mover device and said second member;

wherein:

(e) said first member is movable with respect to said housing;

(f) said second member is movable with respect to said first member;

(g) when in said first, non-actuated state, said first member extends past said first end of the housing such that said third end of the first member is positioned substantially at a first predetermined distance from said first end of the housing, and said second member extends past said third end of the first member such that said fifth end of the second member is positioned substantially at a second predetermined distance from said third end of the first member;

(h) when in a second state, as said second member is pushed against a solid object, said first member continues to extend past said first end of the housing substantially at said first predetermined distance between said first end of the housing and said third end of the first member, but said second member moves toward said housing and toward said first member, such that said fifth end of the second member becomes positioned from said third end of the first member at a distance less than said second predetermined distance;

(i) when in an third state, as said second member continues to be pushed against said solid object, both said second member and said first member move toward said housing, such that said third end of the first member becomes positioned from said first end of the housing at a distance less than said first predetermined distance;

(j) said second member includes a nose piece member that makes contact with said solid object to cause said second member to be moved toward said housing and toward said first member during a first stage of movement, and to cause said second member to continue to be moved toward said housing during a second stage of movement;

(k) a fastener is moved into a drive position during said first stage of movement; and

(l) said fastener is driven into said solid object by said prime mover device and said intermediate drive device during said second stage of movement;

and further comprising a spring-loaded, pivotable latch lever that:

(m) when said first member and said second member are in their non-actuated states, a first predetermined surface of said latch lever presses against an edge of an opening in a stationary member of said housing, and thereby prevents substantial movement of said first member toward said housing;

(n) until the first stage movement of said second member is substantially completed, said first predetermined surface of the latch lever continues to press against said edge of the opening in the stationary member of said housing, and continues to prevent substantial movement of said first member toward said housing; and

(o) once said first stage movement of said second member is substantially completed, a protruding member that is attached to said second member abuts a second predetermined surface of said latch lever and forces the latch lever to pivot in a manner that causes said first predetermined surface of the latch lever to clear said edge of the opening in the stationary member of said housing, which now allows said first member to move toward said housing.

2. The portable fastener-driving tool as recited in claim 1 , wherein said second member includes a fastener indexer that receives a collated strip of fasteners and moves an individual one of said fasteners of the collated strip to said drive position.

3. The portable fastener-driving tool as recited in claim 1 , wherein said housing is in slidable mechanical communication with said first member, and said first member is in slidable mechanical communication with said second member.

4. The portable fastener-driving tool as recited in claim 1 , wherein: (a) said first member is of a substantially hollow construction with a first interior region, and allows said second member to collapse into said first interior region during said first stage of movement; and (b) said housing is of a substantially hollow construction with a second interior region, and allows said first member to collapse into said second interior region during said second stage of movement.

5. The portable fastener-driving tool as recited in claim 4 , wherein: (a) said prime mover device comprises an electric motor positioned substantially within said second interior region; and (b) said intermediate drive device comprises a gear reduction and clutch sub-assembly positioned substantially within said second interior region.

6. The portable fastener-driving tool as recited in claim 4 , wherein said intermediate drive device comprises a drive bit that extends substantially through said first interior region and engages said fastener at said drive position.

7. A portable fastener-driving tool, comprising:

(a) a housing containing a prime mover device and an intermediate drive device, said housing having an actuation end; (b) a movable first member extending from said actuation end of the housing, said first member having a first distal end; and (c) a movable second member extending from said first distal end of the first member, said second member having a second distal end;

wherein:

(d) in a first, non-actuated state, said second distal end of the second member is substantially at a predetermined first distance with respect to said actuation end of the housing; and

(e) when said tool is actuated by a sufficient force against said second distal end of the second member, said second member begins to move relative to said housing, and:

(i) said second member travels through a first stage of movement from said predetermined first distance, and moves relative to said first member, while said first member is substantially prevented by a first mechanism from moving relative to said housing until said second distal end of the second member reaches substantially a predetermined second distance with respect to said actuation end of the housing; and

(ii) then said second member travels through a second stage of movement from said predetermined first distance and past said predetermined second distance, and said first member moves relative to said housing while overcoming said first mechanism, until said second distal end of the second member reaches substantially a predetermined third distance with respect to said actuation end of the housing, which substantially completes the movement of said second member;

wherein said predetermined first distance is greater than said predetermined second distance, and said predetermined second distance is greater than said predetermined third distance;

and further comprising a spring-loaded, pivotable latch lever that:

(f) when said first member and said second member are in their non-actuated states, a first predetermined surface of said latch lever presses against an edge of an opening in a stationary member of said housing, and thereby prevents substantial movement of said first member toward said housing;

(g) until the first stage movement of said second member is substantially completed, said first predetermined surface of the latch lever continues to press against said edge of the opening in the stationary member of said housing, and continues to prevent substantial movement of said first member toward said housing; and

(h) once said first stage movement of said second member is substantially completed, a protruding member that is attached to said second member abuts a second predetermined surface of said latch lever and forces the latch lever to pivot in a manner that causes said first predetermined surface of the latch lever to clear said edge of the opening in the stationary member of said housing, which now allows said first member to move toward said housing.

8. The portable fastener-driving tool as recited in claim 7 , wherein:

(a) a fastener is moved into a drive position during said first stage of movement; and

(b) said fastener is driven into a solid object by said prime mover device and said intermediate drive device during said second stage of movement.

9. The portable fastener-driving tool as recited in claim 7 , wherein said second member includes a fastener indexer that receives a collated strip of fasteners and moves an individual one of said fasteners of the collated strip to a drive position.

10. The portable fastener-driving tool as recited in claim 7 , wherein said housing is in slidable mechanical communication with said first member, and said first member is in slidable mechanical communication with said second member.

11. The portable fastener-driving tool as recited in claim 7 , wherein: (a) said first member is of a substantially hollow construction with a first interior region, and allows said second member to collapse into said first interior region during said first stage of movement; and (b) said housing is of a substantially hollow construction with a second interior region, and allows said first member to collapse into said second interior region during said second stage of movement.

12. The portable fastener-driving tool as recited in claim 11 , wherein: (a) said prime mover device comprises an electric motor positioned substantially within said second interior region; and (b) said intermediate drive device comprises a gear reduction and clutch sub-assembly positioned substantially within said second interior region.

13. The portable fastener-driving tool as recited in claim 11 , wherein said intermediate drive device comprises a drive bit that extends substantially through said first interior region and engages a fastener at a drive position.

14. A portable fastener-driving tool, comprising:

(a) a housing containing a prime mover device, said housing having an actuation end;

(b) a movable first member extending from said actuation end of the housing, said first member having a first distal end;

(c) a movable second member extending from said first distal end of the first member, said second member having a second distal end;

(d) a first spring device that tends to oppose movement between said first member and said housing; and

(e) a second spring device that tends to oppose movement between said second member and said first member;

wherein, when said tool is actuated by a sufficient force against the second distal end of the second member:

(f) during a first stage of actuation, said second member moves relative to said first member, while being opposed by said second spring device, but said first member does not substantially move relative to said housing due to said first spring device; and

(g) during a second stage of actuation, said first member moves relative to said housing, while being opposed by said first spring device;

and further comprising a spring-loaded, pivotable latch lever that:

(h) when said first member and said second member are in their non-actuated states, a first predetermined surface of said latch lever presses against an edge of an opening in a stationary member of said housing, and thereby prevents substantial movement of said first member toward said housing;

(i) until the first stage of actuation of said second member is substantially completed, said first predetermined surface of the latch lever continues to press against said edge of the opening in the stationary member of said housing, and continues to prevent substantial movement of said first member toward said housing; and

(j) once said first stage of actuation of said second member is substantially completed, a protruding member that is attached to said second member abuts a second predetermined surface of said latch lever and forces the latch lever to pivot in a manner that causes said first predetermined surface of the latch lever to clear said edge of the opening in the stationary member of said housing, which now allows said first member to move toward said housing.

15. The portable fastener-driving tool as recited in claim 14 , wherein:

(a) a fastener is moved into a drive position during said first stage of actuation; and

(b) said fastener is driven into a solid object by said prime mover device and an intermediate drive device during said second stage of actuation.

16. The portable fastener-driving tool as recited in claim 14 , wherein said second member includes a fastener indexer that receives a collated strip of fasteners and moves an individual one of said fasteners of the collated strip to a drive position.

17. The portable fastener-driving tool as recited in claim 14 , wherein said housing is in slidable mechanical communication with said first member, and said first member is in slidable mechanical communication with said second member.

18. The portable fastener-driving tool as recited in claim 14 , wherein: (a) said first member is of a substantially hollow construction with a first interior region, and allows said second member to collapse into said first interior region during said first stage of actuation; and (b) said housing is of a substantially hollow construction with a second interior region, and allows said first member to collapse into said second interior region during said second stage of actuation.

19. The portable fastener-driving tool as recited in claim 18 , wherein: said prime mover device comprises an electric motor positioned substantially within said second interior region.

20. The portable fastener-driving tool as recited in claim 18 , further comprising a drive bit that extends substantially through said first interior region and engages a fastener at a drive position.