Male fastener extractor device

Abstract

A fastener extractor device for removing fasteners and disengaging the extractor from the so engaged fastener. The extractor includes a threaded main body with a hex drive head end portion and oppositely disposed elongated tool engagement hex body with multiple bracing sidewalls with independent contoured fastener engagement channels for fastener insertion and continued rotational removal. A tubular hex surface extractor nut is threadably disposed on the main body member for reversed thread rotation advancement to physically disengage the tool engagement body from the removed fastener.

Claims

1. A fastener extractor device comprising, a shank bit body having a drive head end and oppositely disposed fastener socket engagement portion having a free end, a plurality of flat fastener engagement surfaces about said fastener engagement portion defining lateral edges there between, at least one contoured fastener engagement channel extending angularly across from one respective flat surface's lateral edge to another flat surface lateral edges at least one of said flat fastener engagement surfaces, said fastener engagement channel having first and second spaced parallel lateral fastener engagement edges extending between said respective flat surface lateral edges, an external left-hand thread extending between said fastener socket engagement portion and said drive head end, a threaded shoulder nut fitting being laterally engaged on the exterior left hand thread portion of the shank bit body with an open-end surface having a plurality of unidirectional abutting serrations for removed fastener engagement and release from said fastener extractor device upon rotation thereof.

2. The fastener extractor device set forth in claim 1 wherein said shoulder nut fitting has a hex external drive engagement surface and an annular end surface portion of reduced annular dimension about said open end surface, said unidirectional serrations on said end surfaces.

3. The fastener extractor device set forth in claim 1 wherein said external left-hand thread on said shank body is of a longitudinal length equal to that of said internal thread shank nut portion for longitudinal advancement by counter clockwise rotation thereof.

4. The fastener extractor device set forth in claim 1 wherein said fastener engagement channel extends from said respective flat fastener lateral edges as defined by elongated junctions of said adjacent flat fastener engagement surfaces.

5. The fastener extractor device set forth in claim 1 wherein said fastener engagement channel has a transverse tapered interior surfaces of unequal transverse dimension defining a V-shaped configuration.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an enlarged front elevational view of the fastener extractor tool of the invention.

(2) FIG. 2 is an enlarged perspective view of the shoulder nut extractor sleeve of the extractor tool.

(3) FIG. 3 is an enlarged perspective view of the shank body of the extractor.

(4) FIG. 4 is an enlarged partial front and top view of the fastener extractor tool.

(5) FIG. 5 is an enlarged sectional view on lines 5-5 of FIG. 1.

(6) FIG. 6 is an enlarged top plan view of the fastener extractor tool.

(7) FIG. 7 is a large bottom plan view of the extractor tool.

DETAILED DESCRIPTION OF THE INVENTION

(8) Referring to FIGS. 1-7 of the drawings, a fastener extractor 10 of the invention can be seen having a shank bit body member 11 with fastener release shoulder nut fitting 12 threadably disposed thereon. The shank bit body member 11, best seen in FIG. 3 of the drawings has a hex drive head 13 with an external left-handed thread portion 14 extending longitudinally with a hex shank fastener socket engagement portion 15 extending integrally therefrom. The hex shank fastener engagement portion 15 is characterized by a plurality of elongated flat interengaging fastener engagement surfaces 16 of equal transverse and longitudinal dimension so as defined a hex tool bit configuration known in the art.

(9) The fastener engagement socket is therefore hexagonal with radially positioned fastener engagement surface 16 about its longitudinal axis. The hexagonal shank is of a length which by necessity varies with the size of the shank. A unidirectional angular channel 17 is formed in each of the respective flat fastener engagement surfaces 16 as best seen in FIG. 4 of the drawings. Each of the unidirectional channels 17 are of a descending angular orientation with a contoured transverse tapered interior surface 18 defining a pair of spaced parallel elongated fastener engagement lateral edges 17A and 17B. The angular orientation of each channel 17 extends transversely across the flat engagement surface 16 from the lateral edge 16A end to the corresponding second lateral edge 16B in spaced vertical relation thereto and are sequentially formed about the multiple hex flat engagement surfaces as best seen in FIGS. 4 and 6 of the drawings.

(10) It will be seen as used initially the extractor 10 is driven into a prepared damaged fastener F, seen in FIG. 5 of the drawings in broken lines, and that each of the respective engagement channels 17 will be selectively engaged with the fastener F. When counter clockwise rotational force is applied to the hex head end 13 by a driver, not shown, as indicated by directional arrows FA, the respective channels 17 lateral edges 17A and 17B will correspondingly dig into the fastener interior surface defining multiple gripping points there along the length of each channel thereby affording rotational removal of the damaged fastener F.

(11) Referring now to FIGS. 1, 2, 4 and 5 of the drawings, a fastener release shoulder nut 12 can be seen having an elongated tubular structure with an internal diameter complimentary to the exterior threaded exterior diameter of the shank bit body 13. The fastener release shoulder nut 12 is thereby internally threaded for left hand threaded engagement on the external threaded portion 14 of the shank bit body member 11 during use.

(12) The fastener release shoulder nut 12 has an exterior hex surface 19, for a driver engagement, not shown, with an end opening at 20 of reduced diameter so as to be fitted over the hex shank fastener engagement portion 15 as illustrated in FIGS. 1 and 5 of the drawings.

(13) The reduced annular diameter of the flat end surface nut 21 is configured with a plurality of contoured unidirectional serrations 22, as best seen in FIGS. 4 and 6 of the drawings.

(14) It will be seen that the left-hand threaded 14 engagement on the shank bit body 11 will advance the fasteners release shoulder nut 12 over the hexagonal shank fastener engagement portion 15 by the counter clockwise shoulder nut 12 rotation for direct engagement with the remote removed fastener F within the tool indicated in broken lines in FIG. 5 of the drawings.

(15) As the rotation continues, the unidirectional serrations 22 impinge on the fasteners F, a bi-directional lateral and rotational force is imparted in the opposite direction of the engagement channel 17 thereby effectively removing the fastener F from the fastener extraction tool 10. The sequential steps for removing a broken or damaged fastener F are as follows:

(16) The compromised fastener is prepared for removal by drilling indicated by engagement bore 25 therein. The shoulder nut 12 is threadably fitted as hereinbefore described over the hexagonal shank fastener engagement portion 15 and is positioned at its furthest point from the engagement channel 17 enabled shank portion free end 26. The fastener extractor 10 is then aligned and tapped into the fastener's prepared bore 25 achieving equilateral contact in the bore 25's length and diameter. This effectively assures faster grip within and eliminates the forced expansion to the fastener's thread material. It will therefore be seen that the hereinbefore described angular orientation of the multiple engagement channel 17 within the respective pool's flat engagement surfaces 16 provide an enhanced sure grip and acts as a removal screw upon rotation via the hex drive end 13 drawing the hexagonal shaft 15 of the tool into the fastener F and thereby upon continued rotation rotates the fastener F for selective threaded removal.

(17) Once the fastener F is removed, the shoulder nut 12 is advanced by its left-hand threaded engagement on the shank portion 11 and engages its unidirectional serrations 22 against the securely held fastener and thereby effectively provides counter rotation and the longitudinal force to remove the fastener F from the fastener extractor 10.

(18) It will be seen that this combination of the multiple angular oriented channel induced lateral edge fastener engagement surfaces 17A and 17B provide for enhanced rotational torque and removal of the fastener F. It will be evident that the left-hand threaded shoulder nut 12 having the unidirectional serration surface 22 will upon advancement and engagement with the fastener provide counter-axial rotational lateral force to remove the engaged fastener from the extraction tool 10 thus presents and provides a new and novel improved fastener extractor configuration taking the advantage of applied bi-directional extraction and removal methodology.

(19) It will thus be seen that a new and novel fastener extractor 10 of the invention has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.