Field ofthe Invention The present invention relates to tools for engaging and turning bolts, screws, nuts and similar fasteners having conventional polygonal portions. In particular, the invention relates to a socket especially adapted for engaging and turning polygonal screw or bolt heads or polygonal nuts with rounded corners or which are otherwise deformed.

BackgroundoftheInvention Threaded fasteners such as bolts and screws are widely used in nearly every application to secure machine parts and the like by engaging corresponding threads on a nut or work piece. These bolts and screws are commonly provided with a polygonal head portion having a series of flat surfaces with well defined corners aligned generally parallel to the axis of the threaded portion of the fastener. The head is usually hexagonal in shape, although bolts having square or other polygonal shapes are sometimes found. The polygonal head portion usually has one of a plurality of standard sizes, measured either in metric or English dimensions, so that the head may be engaged by standard size tools. A variety of tools are commonly used to engage fastener heads, including closed and open end

wrenches and sockets driven by a wrench or driver portion. Fastener nuts are also typically polygonal, and may also be engaged by these tools, and any future reference to fastener heads or bolt heads will also be understood to include nuts.

A socket for turning a fastener head generally has a body portion made of a durable material such as hardened steel or the like within which a polygonal receptacle is defined. The polygonal receptacle of the socket has a size appropriate to fit a corresponding standard size head. Sockets generally provide good performance when engaging heads that are in like new condition and on which the polygonal surfaces and corners have not deteriorated. However, after repeated use, a fastener head sometimes becomes deformed, thus impeding the efficacy of a conventional socket wrench as well as other conventional tools.

The most common type of deformation occurring on a fastener head is rounding of the corners on the head. A rounded-off head, which is sometimes referred to as a stripped bolt head, may result from slippage of a wrench, socket or other tool about the fastener head when turning the fastener. Use of an improper tool or wrong size tool to turn the fastener may also damage the head surfaces. The rounded head frequently develops while attempting to turn a fastener that is very tight, or which is corrosively adhered to a surface, work piece or nut. In such situations, conventional sockets and other tools faiD to provide adequate turning power and slip around the fastener head, causing damage to the head.

In the past, attempts to turn fasteners having rounded or stripped heads have enjoyed varying degrees of success. Locking pliers are often used to clamp tightly on the deformed head to turn it. The use of locking pliers, however, often causes further deformation of the head and may even destroy the head

so that the fastener is no longer serviceable. For example, if the pliers are not sufficiently tight, they will slip around the head when a torque is applied. Alternatively, if the locking pliers are applied tight enough to remove a stubborn fastener, the head may be permanently deformed due to compression by the plier jaws.

A particularly problematic situation arises when a deformed fastener head is positioned within a small recessed area. Such recessed areas are frequently found on machine parts, engines and other applications where it is desirable that the fastener head not protrude above an otherwise flush surface. The recessed area for a fastener head is typically only slightly larger in diameter than the size of the fastener head, allowing only enough room for a socket to extend into the recess and engage the fastener head. This arrangement is quite acceptable when the fastener head has well defined surfaces; however, if the fastener head has become rounded or otherwise deformed, locking pliers or other known tools cannot extend into the recessed area to grasp the bolt head such that an adequate torque can be generated to turn the fastener. Other especially designed tools are available which clamp tightly on a deteriorated fastener head or which cut into the fastener head, but these tools are also frequently destructive, rendering the fastener permanently unserviceable, or are incapable of engaging a fastener head within tightly constricted areas, or both. For example, U.S. Patent 4,920,834, which issued to Womack et al. on May 1, 1990 shows a socket pipe wrench having an adjustable sliding jaw therein for turning a nut or bolt having a mutilated head. However, the tool shown in the Womack et al '834 patent cannot engage fastener heads within tightly constricted areas due to its relative bulk, and the jaw teeth may cause further damage to a deformed fastener head

received therein. Likewise, U.S. Patent 2,746,328, which issued to Valvano on May 22, 1956, shows a tool having wedge-like moveable jaws. However, this tool is especially adapted for removing a stud bolt lacking a polygonal head.

Another stud bolt puller is shown in U.S. Patent 3,094,022, issued to Young on June 18, 1963. The Young '022 stud puller has a plurality of bolts aligned transverse to the axis of the stud puller which may be adjusted to engage the stud. This tool, however, is not adapted for turning polygonal fastener heads as it has a circular interior bore. Last, French Patent No. 608,191, issued to Bernard and published July 22, 1926, shows a wing-nut adapter which has a socket for engaging the hexagonal head of a spark plug. A screw penetrates one vertex of the socket and may be adjusted to retain the adapter on the head; however, the adapter cannot securely engage a deformed head.

Summaryofthe Invention In light of the aforementioned deficiencies, it is an object of the present invention to provide a new tool for grippingly engaging the head portion of a threaded fastener and transferring a torque to the head to turn the fastener. Another object of the present invention is to provide a socket that will extend into a recessed area to engage a fastener having a deformed head.

Yet another object of the present invention is to provide a compact, inexpensive tool for engaging a rounded fastener head without causing further deformation of the head.

A further object of the present invention is to provide a socket for turning fasteners having rounded heads which is compatible with conventional socket wrenches and drivers.

The above and other objects and advantages of the present invention are achieved in the embodiments described herein by the provision of a socket including at least one set screw which projects through the socket body into its polygonal fastener head receptacle. The set screw(s) are adjusted to securely engage a fastener head with the polygonal receptacle. The set screw(s) may be easily and inexpensively added to a standard socket wrench set to allow removal of a rounded bolt head without causing further deformation of the bolt head. Moreover, since the set screw(s) may be flush with the outer surface of the socket, the socket may be extended into a recessed area to engage a bolt head therein. In particular, the socket of the present invention comprises a generally tubular socket body having first and second ends. A means for mating with a drive portion of a tool such as a socket wrench or driver is provided at the first end of the socket body, and an appropriately sized polygonal receptacle for receiving the head portion of a fastener is defined at the second end of the socket body. In a preferred embodiment, a pair of threaded holes penetrate the socket body in a plane displaced above the second end of the socket body. The holes form an angle of about sixty degrees relative to each other about the axis of the socket body. The threaded holes open into the polygonal receptacle and receive two set screws which may be adjusted in the direction of the axis of the socket body by turning with an alien wrench or the like.

The set screws may therefore securely engage portions of a fastener head within the polygonal receptacle to urge the head against a wall segment of the receptacle to retain the head in a fixed position relative to the socket body when the socket body is turned by a wrench or other driving tool. Thus, the

socket securely grasps and turns the fastener, notwithstanding the presence of deformed head surfaces. Although the preferred embodiments described herein are provided with a polygonal receptacle for use with a polygonal fastener, it is to be understood that a socket of the present invention may be provided with a suitable receptacle for use with any fastener having at least one flattened portion which may be engaged by a flattened wall segment of the receptacle.

Brief Description ofthe Drawings

The foregoing and other objects, advantages and features of the invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, and wherein:

Figure 1 is a perspective environmental view of one preferred embodiment of a tool made in accordance with the present invention;

Figure 2 is a cross sectional view taken along the line 2-2 of Figure l;

Figure 3 is a cross sectional view of another preferred embodiment of the present invention; and Figure 4 is a partial cross sectional view taken along the axis of the socket body which shows the socket engaging a fastener head within a recessed area.

Description of the Preferred Embodiment

Referring now to the drawings, Figure 1 is a perspective view of one preferred embodiment of a tool made in accordance with the present invention designated generally at 10. As shown therein, the tool 10 includes an interchangeable socket, designated generally at 11, and a wrench 12 having a turning head 13 and an extended handle 14 for generating a torque

about the turning head 13. The turning head 13 may include a ratchet 15 so that the wrench 12 will exert a turning force in one direction only. Alternatively, the wrench 12 may be of any type suitable for generating a moment about the socket 11, including a stiff arm or breaker bar, or a screwdriver like tool having a handle aligned collinear with the axis of the socket 11. The turning head 13 may include ratchet 15 and a drive end 16. In a preferred embodiment, the drive end 16 has a generally square cross section on which the corners are beveled. The design of wrench 12 is well known to those having skill in the art and need not be described further herein.

The socket 11 includes a socket body 20, which is made of hardened steel or another suitable durable material. The socket body 20 has a generally tubular shape, although other shapes may be used, and has a first end 21 and a second end 22 arranged transverse to its longitudinal axis. The first end 21 defines means for mating with the drive end 16 of the wrench 12. In a preferred embodiment, the means for mating with the drive end 16 is a rectangular opening 23 which is of an appropriate size to receive the drive end 16 therein. A beveled surface 24 may also extend around the upper portion of the rectangular opening 23 to facilitate insertion of the drive end 16 into the rectangular opening 23.

A polygonal receptacle 25 is defined at the second end 22. The polygonal receptacle 25 extends substantially into the interior of the socket body 20. The polygonal receptacle 25 has a size, typically of English or metric proportions, which is selected so that the receptacle 25 fits closely over a standard size head H of a threaded fastener such as a bolt, screw or the like. The polygonal receptacle 25 has a depth measured from the second end 22 that is sufficient to permit all or substantially all of the

fastener head H to fit within the receptacle 25. Ideally, the polygonal receptacle 25 is sufficiently deep to allow the socket 11 to completely enclose the fastener head H, so that the second end 22 abuts against flange F of the fastener head H.

The design of socket 11 is well known to those having skill in the art, and will not be described further herein. As is also known to those having skill in the art, one or more wrenches and a plurality of sockets of different sizes are widely sold as "socket wrench sets". Likewise, a plurality of sockets having different sizes may be sold as a "socket set."

Still referring to Figure 1, at least one engagement means is mounted in the socket body 20 adjacent the second end 22. The engagement means extends into the polygonal receptacle 25 and is adjustable in a direction perpendicular to and intersecting the longitudinal axis of the socket body 20. The engagement means is adapted to engage a flat portion of a fastener head H received within the polygonal receptacle 25 to urge the fastener head H against the side of the polygonal receptacle 25.

In a preferred embodiment, the engagement means comprise at least one threaded hole 30 which extends through the socket body 20. A set screw 31 having a size appropriate to engage threads in hole 30 is received within the hole 30. In a preferred embodiment, two holes 30 penetrate the socket body 20 at an angle of about 60" relative to one other in a plane generally perpendicular to the longitudinal axis of the socket body 20.

The set screws 31 may include a means for engaging a tool so that the set screws 31 may be easily turned. In a preferred embodiment, the means for engaging a tool on set screws 31 comprise an alien wrench receptacle 32. Alternatively, however, a slot

for a screwdriver may be used, or the tool engaging means may be omitted altogether, in which case the set screws 31 may be turned manually.

In a preferred embodiment, the edges of the holes 30 and set screws 31 that are closest the second end 22 are displaced from the second end 22 by at least about 0.0625 inch. This displacement of the holes 30 and set screws 31 may be increased on sockets for turning large fastener heads, and may be decreased on sockets for turning small fastener heads. In the preferred embodiments, the diameters of the threaded holes 30 and the set screws 31 may vary between about 0.1 to 0.5 inch.

Figure 2 illustrates a cross sectional view of one preferred embodiment of the socket 11 of the present invention, in which the polygonal receptacle 25 is a hexagonal opening 33. In this embodiment, the threaded holes 30 and set screws 31 pass through wall segments 34 of the hexagonal opening 33 and are preferably centered on adjacent wall segments 34 of the hexagonal opening 33.

In an alternative embodiment, as illustrated in Figure 3, the polygonal receptacle 25 may be a dodecagonal opening 35. The dodecagonal opening 35 has twelve wall segments 34 adjoined by alternating acute vertices 36 and obtuse vertices 37. The acute vertices 36 of the dodecagonal opening 35 point towards the exterior of the socket body 20, whereas the obtuse vertices 37 point toward the center of the socket body 20. As shown in Figure 3, in this embodiment the threaded holes 30 and set screws 31 are preferably positioned on acute vertices 36. Although only one threaded hole 30 and set screw 31 may be used, the preferred embodiment includes two threaded holes 30 and set screws 31 at a 60* angle relative to one another in a plane generally perpendicular to the longitudinal axis of the socket body 20.

The multiple holes 30 and set screws 31 may be positioned on nonadjacent wall segments 34 of a hexagonal opening 33. Likewise, the multiple holes 30 and set screws in a socket body 20 having a dodecagonal opening 35 may be set at angles other than 60 ^β .

Moreover, it is unnecessary that the holes 30 and set screws 31 intersect the axis of the socket body 20, although that arrangement has been found desirable.

As illustrated in Figures 2, 3 and 4, the set screws 31 may be adjusted by turning, thereby causing the set screws 31 to advance along the threads of threaded hole 30 and resulting in axial adjustment of the set screws 31 toward the interior of the polygonal receptacle 25. Such adjustment of the set screws 31 may be used to move the foot portions 40 of the set screws 31 into a position adjacent flat portions of a fastener head H, thereby urging the head against the wall segments 34 opposite the set screws 31.

In use, the set screws 31 may be adjusted either when the fastener head H is within the polygonal receptacle 25 or before the socket body 20 is positioned over the fastener head H. It is generally preferable to adjust the set screws 31 after the head H is within the receptacle 25. However, as illustrated in Figure 4, in some applications, it may be impossible to adjust the set screws 31 after the socket body 20 has been placed on the fastener head H due to space constraints. In this case, the set screws may be adjusted by trial and error, or may be adjusted using another fastener head of the same size as fastener head H.

The set screws 31 may be adjusted by hand such that they engage flat portions of a fastener head H relatively loosely. Alternatively, a tool such as an alien wrench may be used to drive the set screws 31 tightly against a fastener head H if a more secure engagement is desired. Of course, the socket 11 of the

present invention may be used to turn fasteners both for tightening and loosening them.

In a preferred embodiment, the engagement means of the present invention is provided in all sockets of a socket wrench set to facilitate removal of all sizes of rounded fastener heads. Alternatively, some but not all of the sockets of a socket wrench set may include the engagement means. As another alternative, individual sockets having engagement means may be sold.

In the drawings and specification, there have been disclosed typical preferred embodiments of the invention. Although specific terms have been employed, they have been used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.