Device and Method for Broken Extractor Removal

Abstract

A device and method of extracting a broken extractor are provided. The fastener extractor includes a shaft with a pre-formed center hole situated longitudinally and interiorly in the fastener extractor. An extractor removal tool is provided that is preformed to engage the pre-formed center hole in the extractor for removing a broken extractor and debri.

Description

BACKGROUND

1. Field

The present invention relates to traditional extractors used for removing broken threaded fasteners and more specifically extracting a broken extractor from a broken fastener.

2. Description of Related Art

Conventional extractors are solid, formed to a point, and threaded in the opposite direction of the broken fastener that is to be removed. The extractor is formed in a way that once the broken fastener is center drilled the extractor is then inserted and rotated to remove the broken fastener. These conventional extractors leave no room for error in the aspect that if the extractor breaks or snaps off while attempting to remove the damaged fastener, it leaves a broken extractor inside of the broken fastener, therefore creating a compounded problem.

Traditional extractors are comprised of very hard steel, usually case hardened or fully heat treated, causing the steel to become so hard that it is almost brittle. It is well known to those that have utilized the conventional extractor not to drop them on concrete or other equally hard surfaces as it can easily compromise the strength of the extractor and will likely fail when used. Extractors are not easily drilled into by the common drill bit therefore, ruining multiple drill bits to achieve a deep enough hole in the broken extractor for it's removal. In some cases, removal of the broken extractor from the broken fastener cannot be achieved. This can present a time consuming and labor intensive process that can result in further damage or destruction of the bored component.

Many different extractors have been invented solving various problems presented while attempting to remove a damaged fastener, see for example U.S. Pat. Nos. 1,458,076, 1,754,736, 1,798,944, 1,875,484, 5,466,100, 6,098,499 and 7,152,509.

In U.S. Pat. No. 1,458,076 an “Extracting Device” having a nut member and angular portion that is engagable by a turning tool.

U.S. Pat. No. 1,754,736 is a “Screw Extractor” providing a tapered end with spiraled tapering with a blank surface between threads.

U.S. Pat. No. 1,798,944 claims a self centering extractor with an impact head for hammering and flat narrow surfaces to allow for better seating in the broken fastener.

U.S. Pat. No. 1,875,484 discloses an extractor having a square body used to transmit rotational forces on the wall of the screw without shearing the metal.

U.S. Pat. No. 5,466,100 is directed to an extractor having a multispeed power drill bit with handle chuck adapter. This extractor has a hexagonal shank and multiple cylindrical surfaces with a decreasing diameter and a groove extending down the shank.

U.S. Pat. No. 6,098,499 is yet another extracting tool that has a tap member and driving head end and broach end.

U.S. Pat. No. 7,152,509 titled “Fastener Extractor” comprises an extractor and hand tool used on the end of the extractor for removing the fastener.

Accordingly, it is evident these conventional extractors do not address the possibility of the extractor itself being compromised while attempting to remove a damaged fastener, thus further complicating the fastener removal process. Therefore, it would be desirable to have a fastener extractor that did not need to be drilled in the event it broke off in the fastener and overcomes one or more of the disadvantages of the conventional extractor.

BRIEF SUMMARY OF THE INVENTION

To alleviate the disadvantages of prior art, a fastener extractor is provided herein. The present invention comprises the conventional extraction tool for broken fasteners. Conventional extractors are normally solid and formed to a point or taper from the head to the end having gripping teeth, edges, surfaces etc. on the outside of the shaft of the extractor that grip the drilled out broken fastener when the extractor is inserted and turned in the opposite direction of the threaded bolt. The head is formed to have a surface for a wrench, or other hand tool to engage for removal of the broken fastener.

The present invention comprises the conventional extractor having a pre-formed hole longitudinally located through the center of the extractor with the hole opening situated in the center of the head of the extractor. The pre-formed center hole runs through the entire extractor from the opening in the head to an opening in the distal end. The extractor's hardened steel provides strength and rigidity even with a center hole pre-formed longitudinally. The pre-formed center hole also serves as a storage compartment for the extractor removal tool that when in its stored position provides additional strength to the extractor by filling the void in the pre-formed center hole. In the event the extractor fractures, the preformed center hole allows for ease of removal of the fractured extractor with the extractor removal tool. Thus eliminating the step of trying to drill out the conventional extractor, which is tedious, time consuming and sometimes impossible due to the nature of the case hardened steel from which the extractor is composed. The extractor removal tool is pre-formed to fit inside the current invention so that when rotated will unthread the compromised extractor for ease of removal from the broken fastener. The extractor removal tool is comprised of hard steel (ex. 4140 steel or the like thereof because there are various metal compositions with low carbon that provide both qualities) that allows the steel of the removal tool to grip and bite the interior of the broken extractor all while the steel will give enough that the extractor removal tool won't snap. This allows for an uncompromised extractor with pre-formed center hole to be reinserted in the broken fastener and the process starts again. The current invention alleviates the possibility of permanently damaging the bored component and the necessity of drilling into case hardened steel, which is consequently a long involved process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the current invention showing the extractor with a pre-formed center hole.

FIG. 2 is a perspective view of the extractor removal tool that is pre-formed to fit in the center hole of the extractor.

FIG. 3 is a perspective view of the current invention showing the extractor removal tool stored in the extractor with pre-formed center hole.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of the current invention, an extractor with pre-formed center hole 2 comprised of case hardened or heat treated steel having a pre-formed center hole 4 longitudinally located through the center of the extractor with an opening in the center of the head and the distal end. The fastener extractor with pre-formed center hole 2 has a head having a plurality of surfaces and ridges adapted to be engaged with a wrench or other hand tool of the like. The distal end being the broach end is comprised of various gripping teeth, edges and surfaces on the exterior of the extractor used to grip a broken fastener. FIG. 2 is a perspective view of the current invention showing an extractor removal tool 6. The extractor removal tool 6 having a longitudinal axis is further defined by having a sliding head 8, a head keeper 10, and a distal end shaft. The sliding head 8 of the extractor removal tool 6 is formed with a through center hole engagable on the shaft of the extractor removal tool 6 and is able to slide freely on the shaft allowing the sliding head 8 to move closer to a bored component containing a broken fastener and broken extractor for ease in removing the broken extractor. Above the sliding head 8 attached to the shaft of the extractor removal tool is the head keeper 10 that is utilized to stop the extractor removal shaft from sliding through the bottom of the sliding head 8. The extractor removal tool 6 seats and engages in the pre-formed center hole 4 of the extractor with pre-formed center hole 2. FIG. 3 is a perspective view showing the extractor removal tool in its stored position 12 within the extractor with pre-formed center hole 2. The extractor removal tool 6 is comprised of hard steel with lower carbon composition and is pre-formed in a manner so that when inserted into the extractor with pre-formed center hole 2 it fills the void of the pre-formed center hole 4. The hard steel (ex. 4140 steel, alloys or the like there of) comprising the extractor removal tool 6, sliding head 8 and head keeper 10 allows for the tool to give rather than break but is rigid enough to grip or bite the interior walls of the extractor's pre-formed center hole 4 while being rotated to remove a broken extractor with a pre-formed center hole 4. The extractor removal tool 6 is also magnetized to aide in the extractor and debri removal. The pre-formed center hole 4 of the extractor, the extractor removal tool's 6 shaft, and sliding head 8 can be machined or formed in a plurality of shapes including but not limited to: circle, square, cross, hexagon, octagon, ribbed, etc. Rotating the extractor removal tool 6 in the opposite direction the extractor was applied allows for easy removal of the broken extractor with pre-formed center hole. Once a broken extractor with pre-formed hole 4 is removed from a broken fastener, the process is repeated using an unbroken extractor with a pre-formed center hole 2 to remove the broken fastener.

Due to the case hardening or heat treating of the steel used to construct extractors, machining of the pre-formed center hole 4 must occur before the hardening process takes place in order to allow for easy and economical machining. It is assumed that one skilled in the art has knowledge of the aforementioned hardening process. While the present invention has been described in both summarized and detailed form, it is understood that the pre-formed center hole 4, extractor removal tool's 6 shaft and sliding head 8 can be comprised of various shapes (ie. hexagon, octagon, circle, square, etc.) and can be integrated into various types and brands of extractors without departing from the spirit of the invention. Therefore I claim:

Claims

1. A fastener extractor comprising: a shaft defining a longitudinal axis: a shaft member comprised of heat treated or case hardened steel having a head with engagement opening and broach end, said engagement opening having machined and pre-formed center hole positioned interiorly and longitudinally through the center of the extractor shaft prior to completion of hardening process:the pre-formed center hole having a plurality of surfaces further comprised of various shapes depending on application and having a through hole that extends through the distal end of the extractor broach end; andsaid shaft being conical or square with a plurality of gripping or biting surfaces an edges along the longitudinal axis being the broach end; andthe said head having the machined and pre-formed center hole interiorly; andthe head having a plurality of surfaces and ridges exteriorly adapted to be engaged with a wrench or other hand tool of the like.

2. An extractor removal tool comprising: a shaft defining a longitudinal axis: a shaft member comprised of low carbon steel or alloy also being magnetized, having a head with a plurality of surfaces and ridges adapted to be engaged with a wrench or other hand tool of the like with the shaft exterior having a machined and pre-formed shape conformed to fill the void of the aforementioned fastener extractor center hole in claim 1; andsaid head having a center hole pre-formed to engage on the shaft and allow the head to slide freely on the shaft; andthe shaft member having a length such that when positioned in the downward most position within the fastener extractor, extends above the head of the extractor when in the seated or stored position; andsaid shaft member having a head keeper to alleviate the head from sliding off the top of the shaft; andsaid shaft member having a rotational direction opposite of the fastener extractor in claim 1.

3. A method of extracting a damaged extractor comprising: the absence of drilling an opening into the hardened steel of a broken extractor;providing a fastener extractor having a shaft defining a longitudinal axis; the shaft member of heat treated or case hardened steel having a head with engagement opening and broach end, with said engagement having machined and pre-formed center hole positioned interiorly and longitudinally through the center of the extractor prior to completion of the hardening process, where the pre-formed center hole has a plurality of surfaces further comprised of various shapes depending on application and having a through hole that extends through the distal end of the extractor broach end, with said shaft being conical or square with a plurality of gripping and biting surfaces an edges along the longitudinal axis being the broach end, with the head having the said machined and pre-formed center hole interiorly and exteriorly having a plurality of surfaces and ridges adapted to be engaged with a wrench or other hand tool of the like, having an extractor removal tool comprising:a shaft defining a longitudinal axis where the shaft member is comprised of low carbon steel or alloy also being magnetized, and having a head with a plurality of surfaces and ridges adapted to be engaged with a wrench or other hand tool of the like, with said head being able to slide freely along said shaft exterior having a machined and pre-formed shape conformed to fill the void of the aforementioned fastener extractor center hole, where the shaft member has a length such that when positioned in the downward most position within the fastener extractor, the extractor removal tool head extends above the head of the extractor when in the seated or stored position, and the extractor removal tool has a rotational direction opposite of the fastener extractor, and said shaft curtails the head at the top of the shaft with a thin flat steel head keeper attached to the top of said shaft.

4. The method of claim 3 wherein inserting the extractor removal tool into a broken fastener extractor with pre-formed center hole comprises rotating said extractor removal tool in the opposite direction said fastener extractor was applied.