Slide mechanism for expandable bit screw holding screwdriver

Claim 2

In an expandable bit screwholding screwdriver wherein a pair of mating, elongated diverging shank elements are compressed together to move blade elements formed at one end of the shank elements from a blade thin state to a blade thick state and vice versa, the improvement comprising a slide mechanism for creating a positive mechanical force adapted to move the shank elements between said blade thin and blade thick states, said slide mechanism comprising: a twist in said shank elements, intermediate the ends thereof, formed such that the shank formed by said shank elements becomes a twisted split shank; and, an elongated tubular slide mounted about said twisted split shank, said slide including a shaped aperture formed in both ends thereof, said shaped apertures each having perpendicular long and short axes, said apertures being positioned such that the long and short axes of the apertures are angularly displaced with respect to one another about the longitudinal axis of said tubular slide, said shaped apertures contacting the shank elements such that longitudinal movement of said slide causes said tubular slide to rotate about said shank elements and said positive mechanical force to occur.

Claim 3

The improvement claimed in claim 1 wherein said shaped apertures are located on both sides of the twist in said twisted split shank when said shank elements are in said blade thin state.

Claim 4

The improvement claimed in claim 2 wherein said slide is cylindrical, the region of said cylindrical slide located between said shaped apertures having a cross-sectional area greater than the cross-sectional area of said shaped apertures.

Claim 5

The improvement claimed in claim 3 wherein the cross-sectional configuration of each shank element of said twisted split shank includes a flat mating surface that mates with the other shank element along a plane that twists in the area of said twist in said shank elements.

Claim 6

The improvement claimed in claim 4 wherein said shaped apertures include a pair of parallel opposing flat surfaces.

Claim 7

The improvement claimed in claim 5 wherein said twisted split shank has an overall rectangular cross-sectional configuration.

Claim 8

The improvement claimed in claim 5 wherein at least a portion of the outer surfaces of the overall twisted split shank are curved.

Claim 9

The improvement claimed in claim 5 wherein said twisted split shank has a generally rectangular cross-sectional configuration, less the outer corners thereof.

Claim 10

The improvement claimed in claim 5 wherein said twisted split shank has a generally rectangular cross-sectional configuration, less adjacent corners of the shank elements.

Claim 11

The improvement claimed in claim 5 wherein said twisted split shank has a rectangular cross-sectional configuration and said mating surface lies along a transverse plane that is oblique to said generally rectangular cross-sectional configuration and passes through opposing edges thereof.

Claim 12

The improvement claimed in claim 5 wherein said twisted split shank has a non-rectangular parallelogram cross-sectional configuration.

Claim 13

The improvement claimed in claim 5 wherein said twisted split shank has an oval cross-sectional configuration.

Claim 14

The improvement claimed in claim 4 wherein the cross-sectional configuration of said shaped apertures is defined by a pair of adjacent, similarly formed, generally circular regions, each of said regions covering an arc of substantially more than 180°, but less than 360°, said regions joining at the terminal ends of their respective arcs.

Claim 15

The improvement claimed in claim 13 wherein said twisted split shank has a cross-sectional configuration defined by a pair of circular elements terminating in flat sides, each of said circular elements having a circular surface covering an arc of substantially greater than 180°, but less than 360°, said elements mating along their flat sides.

Claim 16

The improvement claimed in claim 4 wherein said twisted split shank has a generally rectangular cross-sectional configuration with opposing, non-mating surfaces of each shank element being curved.

Claim 17

The improvement claimed in claim 1 including a stop mechanism for preventing said slide from sliding off the blade element end of said twisted split shank.

Claim 18

The improvement claimed in claim 1 wherein the twist in said shank elements defines an arc of approximately 90° and wherein said long and short axes of said shaped apertures are displaced by approximately 90°.

Claim 19

The improvement claimed in claim 1 wherein said shank elements diverge in directions such that said shank elements remain in contact in the region of twist when said elongated tubular slide is moved toward said blade element end of said twisted split shank.

Claim 20

In an expandable bit screwholding screwdriver comprising an elongate shank including a pair of shank elements, having blade tips formed at one end, movable between a position whereat the shank elements diverge outwardly such that the blade tips lie in a blade thin state and a position whereat the shank elements are in alignment such that the blade tips lie in a blade thick state; and, a slide mounted on said elongate shank for longitudinal movement toward and away from said blade tips, movement toward said blade tips causing said shank elements to move from a divergent position toward an aligned position, the improvement comprising: guide means formed in said elongate shank, said guide means including a helical path; and, elongate guide follower means formed in said slide, said guide follower means including first and second shaped apertures spaced along the longitudinal length of said slide, said first of said shaped apertures surrounding said shank elements between one end of said helical path and said blade tips and said second of said shaped apertures positioned adjacent to said helical path, said second shaped aperture formed such that longitudinal movement of said slide toward said blade tips causes said slide to rotate about said shank, as a result of coaction between said helical path and said second shaped aperture, said rotation being in one direction when said slide is moved toward said tips and in the opposite direction when said slide is moved away from said tips, said first shaped aperture formed such that it coacts with said shank elements to move said shank elements from said divergent position toward said aligned position when said slide rotates as it moves toward said blade tips and from said aligned position toward said divergent position when said slide rotates as it is moved away from said blade tips.

Claim 21

In an expandable bit screwholding screwdriver comprising an elongate shank including a pair of shank elements, having blade tips formed at one end, movable between a position whereat the shank elements diverge outwardly such that the blade tips lie in a blade thin state and a position whereat the shank elements are in alignment such that the blade tips lie in a blade thick state; and, a slide mounted on said elongate shank for longitudinal movement toward and away from said blade tips, movement toward said blade tips causing said shank elements to move from a divergent position toward an aligned position, the improvement comprising: guide means formed in said elongate shank, said guide means including a helical path; and, elongate guide follower means formed in said slide, said guide follower means including first and second shaped apertures spaced along the longitudinal length of said slide, said first of said shaped apertures surrounding said shank elements between one end of said helical path and said blade tips and said second of said shaped apertures positioned adjacent to said helical path, said second shaped aperture formed such that longitudinal movement of said slide toward said blade tips causes said slide to rotate about said shank, as a result of coaction between said helical path and said second shaped aperture, said rotation being in one direction when said slide is moved toward said tips and in the opposite direction when said slide is moved away from said tips, said first shaped aperture formed such that it coacts with said shank elements to move said shank elements from said divergent position toward said aligned position when said slide rotates as it moves toward said blade tips and from said aligned position toward said divergent position when said slide rotates as it is moved away from said blade tips.

Claim 22

The improvement claimed in claim 19 wherein at least one of said shaped apertures has perpendicular long and short axes.

Claim 23

The improvement claimed in claim 19 wherein said guide means is formed by a twist in said pair of shank elements, said twist forming said helical path.

Claim 24

The improvement claimed in claim 19 wherein said guide means is formed by a separate elongate guide element having a helical path in its outer periphery, said shank elements extending coaxially longitudinally outwardly from one end of said elongate guide element.

Claim 25

The improvement claimed in claim 22 wherein said shank elements are linear.

Claim 26

The improvement claimed in claim 23 wherein said second shaped aperture has a cross-sectional configuration similar to the cross-sectional configuration of said elongate guide element, and wherein said first shaped aperture is defined by a pair of adjacent, similarly formed, generally circular regions, each of said circular regions covering an arc of substantially more than 180°, but less than 360°, said regions joining at the terminal ends of their respective arcs.

Claim 27

An expandable bit screw holding screwdriver comprising: an elongate handle; an elongate shank extending coaxially outwardly from one end of said elongate handle, said elongate shank including a pair of shank elements having blade tips formed at one end thereof, said shank elements being movable between a position whereat said shank elements diverge outwardly such that the blade tips lie in a blade thin position and a position whereat the shank elements are in alignment such that the blade tips lie in a blade thick position, said elongate shank further including a helical path formed in its outer periphery; and, a slide mounted on said elongate shank for longitudinal movement toward and away from said blade tips, said movement toward said blade tips causing said shank elements to move from said divergent position toward said aligned position and movement of said slide away from said blade tips causing said shank elements to move from said aligned position toward said divergent position, said slide including first and second shaped apertures spaced along the longitudinal length of said slide, said first shaped aperture surrounding said shank elements and said second shaped aperture adapted to follow said helical path as said slide is moved toward and away from said blade tips, said following action causing said slide to rotate in one direction or the other depending on the longitudinal direction of slide movement, said rotation causing said first aperture to move said shank elements between said aligned and divergent positions.

Claim 28

An expandable bit screw holding screwdriver comprising: an elongate handle; an elongate shank extending coaxially outwardly from one end of said elongate handle, said elongate shank including a pair of shank elements having blade tips formed at one end thereof, said shank elements being movable between a position whereat said shank elements diverge outwardly such that the blade tips lie in a blade thin position and a position whereat the shank elements are in alignment such that the blade tips lie in a blade thick position, said elongate shank further including a helical path formed in its outer periphery; and, a slide mounted on said elongate shank for longitudinal movement toward and away from said blade tips, said movement toward said blade tips causing said shank elements to move from said divergent position toward said aligned position and movement of said slide away from said blade tips causing said shank elements to move from said aligned position toward said divergent position, said slide including first and second shaped apertures spaced along the longitudinal length of said slide, said first shaped aperture surrounding said shank elements and said second shaped aperture adapted to follow said helical path as said slide is moved toward and away from said blade tips, said following action causing said slide to rotate in one direction or the other depending on the longitudinal direction of slide movement, said rotation causing said first aperture to move said shank elements between said aligned and divergent positions.

Claim 29

The expandable bit screw holding screwdriver claimed in claim 25 wherein at least one of said shaped apertures has perpendicular long and short axes.

Claim 30

The expandable bit screw holding screwdriver claimed in claim 25 wherein said helical path is formed by a twist in said pair of shank elements.

Claim 31

The expandable bit screw holding screwdriver claimed in claim 25 wherein said helical path is formed in a separate elongate guide element forming part of said elongate shank and said shank elements extend coaxially longitudinally outwardly from one end of said elongate guide element.

Claim 32

The expandable bit screw holding screwdriver claimed in claim 28 wherein said shank elements are linear.

Claim 33

The expandable bit screw holding screwdriver claimed in claim 29 wherein said second shaped aperture has a cross-sectional configuration similar to the cross-sectional configuration of said elongate guide element, and wherein said first shaped aperture is defined by a pair of adjacent, similarly formed, generally circular regions, each of said circular regions covering an arc of substantially more than 180°, but less than 360°, said regions joining at the terminal ends of their respective arcs.