Accessory tool apparatus for use on power drills

• US 5,129,118 A
• Filed: 07/29/1991
• Issued: 07/14/1992
• Est. Priority Date: 07/29/1991
• Status: Expired due to Fees

• Current Assignee: Mark W. Walmesley
• Original Assignee: Mark W. Walmesley
• Inventors: Walmesley, Mark W.
• Primary Examiner(s): Parker, Roscoe V.
• Application Number:
  US07/736,782
• Time in Patent Office: 351 Days
• Field of Search: 7/158, 7/165, 408/239 A, 279/1 A, 279/1 B, 279/1 R
• US Class Current: 7/158
• CPC Class Codes: B25F 3/00 Associations of tools for different working operations with one portable power-drive means; Adapters therefor
• CPC Class Codes: Y10T 279/3418 for particular tool or workpiece
• CPC Class Codes: Y10T 408/957 Tool adapter

Abstract

An improved drill accessory apparatus primarily adapted for selective connection to a power tool such as an electric drill to provide additional functions for such a power tool such as a screwdriving function. The apparatus thereby enables a user to first drill a hole and then drive a screw into that drilled hole with the same tool and without requiring removal of a drill bit first used to drill the hole. More significantly, the present apparatus provides the aforementioned accessory feature while overcoming certain safety disadvantages present in the most relevant prior art. One such safety-directed improvement of the present apparatus is derived from a structural design which uses a spring positioned entirely within a housing thereby precluding safety risks that might otherwise be encountered if an external spring were employed such as that shown in the prior art. Another such safety-based improvement relates to the use of a sleeve which is specifically designed to remain stationary while the remaining structure of the apparatus may rotate at high speed. This feature allows the user to grasp and stabilize the combination of the accessory of the apparatus and the power tool to which it is connected with his free hand without incurring any risk of injury that is presented in the prior art.

Claims

1. An apparatus for attachment to an electric drill for providing at least one additional tool therefor, the apparatus of the type being selectively attached to the chuck holes of the drill, without requiring removal of a drill bit therein, for rotation of a tool-holding shaft by the drill;

the apparatus comprising;

a plurality of balls, each such ball configured for at least partial entry into a respective chuck hole of said drill;

a ball holder of a hollow, generally cylindrical shape and having a first end for holding said shaft and a second end having sockets for holding said balls against adjacent said chuck holes;

a housing positioned in coaxial surrounding engagement with the exterior radial surface of said ball holder, the relative axial positions of said housing and said ball holder determining the radial position of said balls within said sockets; and

a spring positioned within said housing for resisting relative axial motion between said housing and said ball holder, a first compression position of said spring corresponding to a radial position of said balls for locking said balls into said chuck holes and a second compression position of said spring corresponding to a radial position of said balls for releasing said balls from said chuck holes; and

a circumferential sleeve positioned in surrounding radial engagement with said housing and adapted for slippage relative to said housing upon activation of said drill for stabilizing said apparatus by the grasping of a non-rotating portion thereof.

2. An apparatus for attachment to an electric drill for providing at least one additional tool therefor, the apparatus of the type being selectively attached to the chuck holes of the drill, without requiring removal of a drill bit therein, for rotation of a tool-holding shaft by the drill;

the apparatus comprising;

a plurality of balls, each such ball configured for at least partial entry into a respective chuck hole of said drill;

a ball holder of a hollow, generally cylindrical shape and having a first end for holding said shaft and a second end having sockets for holding said balls against adjacent said chuck holes;

a housing positioned in coaxial surrounding engagement with the exterior radial surface of said ball holder, the relative axial positions of said housing and said ball holder determining the radial position of said balls within said sockets; and

a spring positioned within said housing for resisting relative axial motion between said housing and said ball holder, a first compression position of said spring corresponding to a radial position of said balls for locking said balls into said chuck holes and a second compression position of said spring corresponding to a radial position of said balls for releasing said balls from said chuck holes; and

a magnet in said shaft for selective retention of a tool therein.

3. An apparatus for attachment to an electric drill for providing at least one additional tool therefor, the apparatus of the type being selectively attached to the chuck holes of the drill, without requiring removal of a drill bit therein, for rotation of a tool-holding shaft by the drill;

the apparatus comprising;

a plurality of balls, each such ball configured for at least partial entry into a respective chuck hole of said drill;

a ball holder of a hollow, generally cylindrical shape and having a first end for holding said shaft and a second end having sockets for holding said balls against adjacent said chuck holes;

a housing positioned in coaxial surrounding engagement with the exterior radial surface of said ball holder, the relative axial positions of said housing and said ball holder determining the radial position of said balls within said sockets; and

a spring positioned within said housing for resisting relative axial motion between said housing and said ball holder, a first compression position of said spring corresponding to a radial position of said balls for locking said balls into said chuck holes and a second compression position of said spring corresponding to a radial position of said balls for releasing said balls from said chuck holes; and

wherein said shaft is serrated for increased frictional engagement with said first end of said ball holder.

4. An apparatus for attachment to an electric drill for providing at least one additional tool therefor, the apparatus of the type being selectively attached to the chuck holes of the drill, without requiring removal of a drill bit therein, for rotation of a tool-holding shaft by the drill;

the apparatus comprising;

a plurality of balls, each such ball configured for at least partial entry into a respective chuck hole of said drill;

a ball holder of a hollow, generally cylindrical shape and having a first end for holding said shaft and a second end having sockets for holding said balls against adjacent said chuck holes;

a housing positioned in coaxial surrounding engagement with the exterior radial surface of said ball holder, the relative axial positions of said housing and said ball holder determining the radial position of said balls within said sockets; and

a spring positioned within said housing for resisting relative axial motion between said housing and said ball holder, a first compression position of said spring corresponding to a radial position of said balls for locking said balls into said chuck holes and a second compression position of said spring corresponding to a radial position of said balls for releasing said balls from said chuck holes.

5. The apparatus recited in claim 4 further comprising a magnet in said shaft for selective retention of a tool therein.

6. The apparatus recited in claim 4 wherein said spring comprises a helix.

7. The apparatus recited in claim 4 wherein said shaft is serrated for increased frictional engagement with said first end of said ball holder.

8. An apparatus for attachment to an electric drill for providing at least one additional tool therefor, the apparatus of the type being selectively attached to the chuck holes of the drill, without requiring removal of a drill bit therein, for rotation of a tool-holding shaft by the drill;

the apparatus comprising;

a plurality of balls, each such ball configured for at least partial entry into a respective chuck hole of said drill;

a ball holder of a hollow, generally cylindrical shape and having a first end for holding said shaft and a second end having sockets for holding said balls against adjacent said chuck holes;

a spring-biased exterior housing having means for controlling the respective radial positions of said balls for selective locking and unlocking said balls relative to said chuck holes depending upon the relative axial position of said housing and said ball holder; and

a stabiizing sleeve positioned along the exterior radial surface of said housing and adapted for rotational slippage relative to said housing for grasping of said apparatus during rotation of said drill.

9. An apparatus for attachment to an electric drill for providing at least one additional tool therefor, the apparatus of the type being selectively attached to the chuck holes of the drill, without requiring removal of a drill bit therein, for rotation of a tool-holding shaft by the drill;

the apparatus comprising;

a plurality of balls, each such ball configured for at least partial entry into a respective chuck hole of said drill;

a ball holder of a hollow, generally cylindrical shape and having a first end for holding said shaft and a second end having sockets for holding said balls against adjacent said chuck holes;

a spring-biased exterior housing having means for controlling the respective radial positions of said balls for selective locking and unlocking said balls relative to said chuck holes depending upon the relative axial position of said housing and said ball holder; and

a magnet in said shaft for selective retention of a tool therein.