Extension shaft for holding a tool for rotary driven motion

Abstract

An extension shaft for holding a tool for rotary motion of the tool includes a first end adapted to cooperate with a chuck of a handheld instrument and a second end including a tool holder for holding the tool for rotary driven motion thereof. The tool holder includes a base portion operatively connected to the extension shaft and a swivel portion capable of holding the tool. The swivel portion is pivotly coupled to the base portion through a pivot assembly, wherein the tool is capable of being rotated about an angle with respect to an axis of the chuck through rotation of the extension shaft in response to rotation of the chuck.

Description

FIELD OF THE INVENTION[0001]The present invention generally relates to an extension shaft capable of holding a variety of tools to be rotary driven by a handheld instrument; and more particularly, to providing an extension shaft with an increased range of angular movement of the tool with respect to the handheld instrument.BACKGROUND OF THE INVENTION[0002]A handheld instrument capable of being used with multiple types of tools—e.g., drill bits, screwdriver bits, sockets, etc. in standard and metric dimensions—is very popular because it provides a user with the ability to readily adapt the handheld instrument among a variety of workplace needs without requiring the user to carry along an extensive set of individually dedicated tools.[0003]Each tool is fashioned to be axially inserted into a chuck of the handheld instrument, which typically positions the tool in close proximity to the handheld instrument's relatively large handle. As a result, the handheld instrument may at times be r...

AI Technical Summary

Benefits of technology

[0006]Accordingly, the present invention is directed to an extension shaft for holding a tool for rotary driven motion. The extension shaft is capable of being adapted to a handheld instrument having a chuck. The extension shaft includes a first end adapted to cooperate with the chuck and be releasably retained thereby; and a second end adapted to releasably retain the tool for rotary driven motion. The first end of the extension shaft and the chuck have complementarily shaped non-circular cross-sections, wherein the first end has an axis and is capable of being releasably retained by the chuck. The second end of the extension shaft includes a tool holder for holding the tool for rotary driven motion thereof. The tool holder and the tool have complementarily shaped non-circular cross-sections. The tool holder further includes a base portion and a swivel portion. The swivel portion is capable of releasably retaining the tool within the tool holder and is pivotly coupled to the base portion through a pivot assembly. The pivot assembly may include a ball joint operatively connecting the swivel and base portions of the tool holder. Alternatively, the pivot assembly may include a first and a second pin, shaft, or axle, wherein the first and second pins of the pivot assembly are substantially perpendicular to each other and lie substantially within a plane. In either embodiment of the pivot assembly, the tool is capable of being rotated about an angle with respect to an axis of the chuck or extension shaft through rotation of the extension shaft in response to rotation of the chuck. Thus, the tool holder of the present invention provides for the handheld instrument's effective operability to be maintained throughout an increase in the angular variation between the extension shaft and the tool.

[0007]In an additional embodiment of the tool holder, the pivot assembly includes a means for biasing the base and swivel portions into axial alignment when the tool holder is at rest. The predisposition of the pivot assembly to axially align the base and swivel portions will effectively steady the swivel portion and facilitate the insertion and / or removal of the tool.

[0008]In another embodiment of the present invention, a sheath may be placed over the cooperating moving parts of the tool holder to guard against contact therewith while simultaneously allowing the extension shaft to properly operate. The sheath can be a single, unitary piece or multiple pieces. In an alternate embodiment to guard against contact with the moving parts of the tool holder, a spacer can be placed proximate the pivot assembly, e.g., bearing of the ball joint; which will assist in preventing an operator from contacting the area around the rotating and hinging parts of the tool holder.

[0011]The flexible extension shaft may further include a plurality of concentric coil springs in tightly wound adjacent relation extending between and secured to generally cylindrical body portions near the first and second ends of the flexible extension shaft to accommodate deflection of the flexible extension shaft relative to the axis of the chuck, and including a flexible sleeve disposed about the concentric coil springs. The flexible sleeve has cylindrical fittings secured thereto at opposite ends thereof so as to define a shoulder internally of each of the fittings. Each cylindrical fitting is adapted to receive one of the cylindrical body portions therein. The cylindrical body portions are spaced apart by a distance greater than the distance between the shoulders in the cylindrical fittings, which permits limited axial movement of the cylindrical body portions and the concentric coil springs relative to the cylindrical fittings and the flexible sleeve. Such a configuration allows for the flexible extension shaft to be deflectable relative to the axis of the chuck so as to position the second end of the shaft and the tool at an angle relative to the axis of the chuck, so that the tool is capable of being rotary driven by rotation of the chuck and / or handheld instrument through the flexible extension shaft.

[0013]An object of the present invention is to provide an extension shaft for holding a tool utilized with a handheld instrument, wherein the extension shaft is capable of increasing the operating capability of the handheld instrument and tool.

[0014]Another object of the present invention is to provide an extension shaft for holding a tool utilized with a handheld instrument, wherein the extension shaft includes a protective mechanism to safeguard the operator from harmful contact with the moving components of the extension shaft.

Problems solved by technology

As a result, the handheld instrument may at times be rather ineffective for use in spatially confined or difficult-to-reach locations.

For this reason, it has been difficult to use the powered instrument in areas of limited access.

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