CA1232160A

CA1232160A - Stabilizing holding socket

Info

Publication number: CA1232160A
Application number: CA000455303A
Authority: CA
Inventors: Dale L. Ewert
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 1983-09-12
Filing date: 1984-05-28
Publication date: 1988-02-02

Abstract

ABSTRACT

The invention relates to an attachment for a power tool which improves stability particularly when used with self-drilling fasteners having heads with beveled integral washers. The attachment has a generally frustoconical end surface which abuts the beveled integral washer of a fastener head causing the fastener to center itself. The attachment also causes standard fasteners with flat integral washers to center themselves during driving by virtue of the contact between the outer perimeter of the washer with the frustoconical end surface.

Description

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Background and S Q rye of the Invention 1 The invention relates to a power tool attachment for use with self-drilling fasteners having integral washers.

Driving tools of the prior art are generally adapted to apply axial driving forces to a fastener through the same portion of the fastener head as that through which torque is transmitted. For example, see US. patent 4,060,113 and US. patent 3,2~6,749. The present invention is directed to a tool specifically designed for use with self-drilling fasteners where wobbling is a significant factor.

It is an object of the present invention to provide a holding-driving socket attachment which allows self-drilling fasteners to be quickly driven with great stability.

Another object of the invention is to provide a power tool attachment which is capable of stably driving fasteners of various head configurations.

The attachment is preferably used with a hexagonally headed fastener with an integral washer and a drilling tip.
The attachment bus an end adapted to be inserted into or attached to a power tool. The other end has a fastener engaging recess which is adapted to mate with and provide stability to the fastener by transferring axial forces to the fastener through the integral washer, while transferring torque through thy hexagonal head. Furthermore, stability is maximized by designing the recess arch that at least the J

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Case 4198 1 outer perimeter of the integral washer bears against the recess in the attachment.

The above objects, features and advantages will become apparent upon a reading of the following description read in conjunction with the accompanying drawings.

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grief Description of the Drawings 1 Fig. 1 is a perspective view of an attachment of the present invention.

Pig. 2 it an elevation Al view, in partial section, of an attachment of the present invention.

Pig. 3 is a cross-~ectional view of an attachment of the present invention in combination with a self-drilling fastener having a beveled integral washer.

Pig. 4 is a cross-sectional view of an alternative embodiment of the combination of the present invention.

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Case aye Detailed Description of the Invention l Referring now to the drawings in which like parts are designated by the same numerals throughout the various figures, a power tool attachment 10 has a shank 12 with its upper end 14 connectable to a power tool snot shown). The lower end 15 includes a fastener engaging recess 18 comprised of wrenching surfaces 20 and a sloping or frustoconical end surface 22. The recess has means for holding a fastener head which include an elastomeric band 1 which biases a pair of movable steel balls 24. The balls 2 lo are contained within generally cylindrical pockets 26 which communicate with the recess 18.

Fig, 3 shows the preferred embodiment of the invention which comprises a combination of the above described attachment 10 and a headed self-drilling fastener 11. The fastener has an integral washer 23 extending generally laterally from and interjecting with a wrench able head 21.
In this embodiment the washer 23 it beveled such that it is complimentary with the sloping end surface 22 of the attachment. Another significant feature of the invention is the fact that the axial extent of the wrenching flats 20 is generally great enough that axial forces exerted by a workman are transmitted to the fastener at the interface between end surface 22 and the washer 23. To achieve this the portion of the recess 18 having the wrenching flats 20 must generally be greater in length than the axial extent of the wrench able head 21. By transmitting axial force to the fastener with the sloping end surface 22 the fastener will a Case 4198 1 have a tendency to center itself and will therefore have more stability which is especially important when using self-drilling fasteners.

While the preferred embodiment of the invention involves the use of a beveled washer, the advantages of the above described attachment are also available when a standard fastener with a flat integral washer is used. The fastener in Pig. 4 has an integral washer 23 which is flat, and the outer edge 28 of the washer contacts the sloping end surface 22. In this embodiment the self-centering feature is also obtained.

The invention is particularly advantageous when used in combination with fasteners which have non-magnetic portions at the drivex/fastener interlace. This may be the case when a stainless steel fastener is used, or when a mild steel fastener having stainless steel head cap is used. In such cases magnetic means for holding the fastener are ineffective.

While the invention has been described with particularity in reference to the preferred embodiments, it should be noted that numerous alternatives, modifications and equivalents may be made without departing from the spirit and scope of the appended claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

Case 4198

Claim 1. A power tool attachment in combination with self-drilling fastener having a wrenchable head and an integral washer adjacent thereto said attachment comprising a shank with one end attachable to a power tool and a second end having a recess and holding means for releasably gripping a fastener head, said recess having a generally frustoconical end surface, said fastener having a laterally extending washer which abuts said end surface, said recess having a wrenching portion complimentary to said wrenchable head and having an axial dimension sufficient to insure that axial forces applied to said attachment are transmitted to said fastener through said washer thereby substantially reducing any tendency for said fastener to wobble during drilling and driving.
Claim 2. The combination according to claim 1 wherein said means includes an elastomeric band around said second end, a pair of balls inwardly biased by said band and held in cylindrical pockets, said pockets disposed on opposite sides of said recess.
Claim 3. The combination according to claim 1 wherein said frustoconical end surface and said washer surface are substantially complimentary in shape.
Claim 4. The combination according to claim 1 wherein said fastener has an at least partially non-magnetic head.
Claim 5. The combination according to claim 4 wherein said head comprises a mild steel inner portion at least partially enclosed by a stainless steel cap.