Patent Application
20110252925
In a principal aspect the present invention relates to an extractor tool designed to engage fasteners including Torx brand fasteners, particularly those fasteners which have been damaged in some fashion wherein the flutes of the fastener drive opening do not conform with the standard design requirements for the Torx brand or a similar type fastener.
Fasteners for assembly of various mechanical devices typically include a head with an axial shaft that projects from the head. The shaft may be threaded or otherwise configured to provide an attachment feature. The head is usually configured to have a diameter or shape or configuration which exceeds the size and configuration of the transverse dimension of the shaft. Typically the head of the fastener will include a keyed center opening into which a tool may be inserted to effect a fastening operation. Preferably the opening in the head of the fastener is such that the fastener may not only be inserted or driven into stock material by a tool, but also may be removed by the same tool when desired for replacement, repair or the like.
A problem often observed with fasteners of various design is the degradation of the drive opening associated with the head of the fastener. For example, with respect to a Phillips head fastener, the flutes which are to be engaged by a Phillips type screwdriver may degrade and thereby preclude easy removal of the fastener. The same circumstance may occur with respect to Torx brand fasteners as well as other types of fastener products.
To address this circumstance, various patents describe fastener extraction tools which may be used for extraction of broken or degraded fasteners. Following is a list of patents which disclose such tools and methods for extraction:
Various products available in the marketplace designed to effect extraction of fasteners include the following:
Spiral Flute Screw Extractors by Irwin Industrial Tools
Alden 8440P 4-Piece Grabit Broken Bolt and Damaged Screw Extractors Set
Extractor, Multi-Spline, 11/32″ and ¼″ by Snap-on
Screw & Bolt Extractors made in Germany by Elora Werkzeugfabrik
Blackhawk DT-55 Screw Extractor Set sold by Grainger
Seven Piece Square Easy Out Set Screw Extractor by Desco USA
Nonetheless difficulties are encountered when attempting to effectively remove various types of fasteners having drive openings that degrade or are otherwise damaged.
Briefly the present invention comprises a tool as well as a kit of tools which function as an extractor of fasteners particularly Torx brand and other similar types of fasteners wherein the fasteners have degraded and, more particularly, the fastener drive opening in the head of the fastener is degraded or damaged for one reason or another. The extractor tool includes an elongate shank having a center line axis with an impact end and an opposite fastener engaging end. The fastener engaging end is uniquely shaped and compatibly sized for engaging, by way of example, a Torx brand fastener, more particularly, the recess drive opening of such a fastener. The fastener engaging end of the extractor tool thus includes a flat planar distal end surface transverse to the axis of the tool and a nose section extending from that distal, flat end surface. The nose section includes six equally sized and shaped, uniformly pitched flutes. Each of the flutes is separated by equally sized and shaped scalloped grooves. The nose section diverges from the axis of the shank in the range of 10 to 20 degrees from the flat end surface. The flutes are arranged typically in a counterclockwise array, though they may be arrayed in a clockwise sense. The flutes have an outer surface with a radius that is generally transverse to the longitudinal axis of the shank and extend in an arc of about 3 to 10 degrees. The fluted end of the nose section extends to and connects to an intermediate cylindrical section which, in turn, is joined to the impact end of the tool.
A kit of similar tools may be provided wherein the dimensional relationship of each of the tools in the kit is associated with fasteners of a discreet size. Thus the kit may include multiple tools, each of the tools being designed to facilitate extraction of a particular size of fastener.
It is therefore an object of the invention to provide an extractor tool wherein the tool may be impacted at one end to drive a fastener engagement end of the tool into an opening in the head of a fastener to effectively cooperate with flutes and the sides of the opening in the fastener head. In this manner the fastener may be easily engaged and twisted in an appropriate clockwise or counter clockwise direction for removal of the fastener from an assembly or stock material.
A further object of the invention is to provide an inexpensive but highly effective extractor tool.
Another object of the invention is to provide an extractor tool which is easy to manipulate and which is useful with respect to various types of fasteners.
These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.
In the detailed description which follows, reference will be made to the drawing comprised of the following figures:
Referring to the Figures, it is to be understood that
Referring to the Figures, the exemplary extractor includes a fluted, generally frusto-conical or rounded frusto-conical forward end 16 having an axis 14 of symmetry and which terminates with a generally transverse distal end surface that is generally a flat planar surface. Thus as shown in
The fastener engaging end 16 includes a series of six generally equally sized and generally identically shaped flutes such as flute 24 and flute 26. The six flutes are distributed uniformly, radially about the centerline axis 14. Each pair of the flutes is separated by equally sized, equal depth and equally shaped scalloped grooves such as grooves 28 and 30. Thus each groove intersects a pair of adjacent flutes along first and second generally parallel uniformly spaced edges such as edges 32 and 34 in
The flutes 24 and 26 have a pitch which is typically in the range of 20 to 40 degrees in the clockwise direction or counterclockwise direction. The grooves, such as groove 28 between the adjacent flutes 24 and 26, are generally uniform and have a uniform depth along the longitudinal dimension. Of course the grooves and the flutes all merge into the generally cylindrical midsection 18. Attached as Table 1 is a summary of the angular limitations and dimensions of multiple extractor tools of the type described wherein the dimensions set forth are keyed to the size of a Torx brand fastener with the dimensions A through E identified or specified in
As an additional feature of the invention, an axial counterbore opening 40 may be provided extending inwardly from the flat planar distal end surface 12.
While there has been set forth a preferred embodiment of the invention, it is to be understood that the invention is to be limited only by the following claims and equivalents.
