BACKGROUND OF THE INVENTION

This invention pertains to fastener system and more particularly, to a tool having an elongated two-part blade, each part blade having a T-shaped end for engaging a complementary slot in the head of a fastener, for example, a screw, and a sleeve slidable on the tool for securing the two parts of the blade together in engaged relationship with the fastener for inserting said fastener into material when the tool is rotated in one direction and removing the fastener from the material when the tool is rotated in the opposite direction.

In Post Patent No. 4,526,071 there is shown a screw having an undercut T- shaped slot in the head portion. A blade having a transverse bar or projection formed or affixed thereon is adapted to cooperate with a complementary undercut T-shaped slot in the screw for rotating the screw. When considering use of the screw of the Post Patent No. 4,526,071 with higher torque applications or with a power drive, it was recognized that ancillary holding means were needed. Applicant desires to provide a fastener system that will provide a slip proof connection between the tool and the fastener. The fastener or screw and tool disclosed in the said Post Patent were intended primarily for bone surgery. Applicant desires to provide a fastener system that will enable the fastener thereof to be used not only in surgery applications, but also in applications requiring higher torque, for example, automotive applications.

An object of the present invention is to provide a unique fastener system comprising a tool having a two part blade engaging the head portion of a fastener for providing a slip proof connection between the blade on the tool and a slot in the head portion of a fastener, which slot comprises a diametral portion and an undercut chordal portion at each side of the diametral portion.

Another object of the present invention is to provide a unique tool adapted to be used with a fastener having a head portion with a diametral slot and undercut chordal slots at each side, the tool having a two part blade for engaging firmly with the diametral slot and chordal slots in the fastener to firmly secure the blade to the fastener for use and for reducing the risk of injury to the user resulting from unwanted separation of the blade from the fastener.

Yet another object of this invention is to provide a novel tool that will permit secure interlocking engagement of the tool to fasteners, e.g., screws, retained firmly in place, so as to enable removal of such screws.

A further object of this invention to provide a unique tool having a first blade portion integral with the tool and a second blade portion pivoted with respect to the first blade portion and adapted to be selectively locked so as to retain a fastener for allowing the user to insert or remove the fastener with compression or tension forces, without the tool and fastener separating from one another. Other objects and advantages of this invention will be made more apparent hereinafter.

BRIEF DESCRIPTION OF THE DRAWING

There is shown in the attached drawing a presently preferred embodiment of the present invention, wherein like numerals confer to like elements in the various views and wherein: Fig. 1 is a front view of a tool forming part of the fastener system of the present invention;

Fig. 2 is a side view of the tool of Fig. 1, taken from the left side;

Fig. 3 is a front view of the tool, with one of the blade segments pivoted outwardly with respect to the other and illustrating the manner of engaging the blade segments of the tool with a fastener;

Fig. 4 is a perspective view of the fastener of the fastener system of the present invention;

Fig. 5 is an elevation view of the fastener of this invention, illustrating the chordal undercuts at each side of the diametral slot in the head portion of the fastener; and

Fig. 6 is an elevation view of the fastener system, with a part of the head portion being broken away to better illustrate the cooperative relationship between the blade of the tool and the fastener.

BRIEF DESCRIPTION OF THE PRESENT INVENTION

There is shown in Figs. 1 and 2 a tool 10 forming a part of the fastener system of the present invention. The tool comprises an elongated rod 12 having a blade 14 at one end. A handle (not shown) may be suitable secured in non- rotatable relationship to the tool 10 or a power source can be affixed to the tool for rotating same. The blade 14 is comprised of two segments 16 and 18. Part or segment 16 is an extension of the elongated rod 12 and part or segment 18 is pivoted about pivot pin 20 that is joined to segment 16. Sleeve 22 is slidable on the rod or shaft 12 from a position overlapping the blade segments 16 and 18 (as shown in Figs. 1 and 2) to a position releasing the blade segments 16 and 18 (Fig.

3) so that one can be pivoted with respect to the other.

Each blade segment 16, 18 is provided with a transverse bar or projection 26, 28 at the free end thereof. As will be explained more fully later, there is a bar 26, 28 at each side of the blade 14. When in use, the blade 14 will engage with a fastener, for rotating same into and out of engagement with metered, e.g., bone in the human body or metal or plastic components in automotive applications. The tool and fastener comprise the fastener system of the present invention.

Fig. 3 shows the fastener system 30 of this invention which includes both the tool 10 and the fastener 32. Sleeve 22 is slidable upwardly on the elongated rod 12 as seen in Fig. 3 to release the upper portion of blade segment 18 and permit the blade segment 18 to be pivoted to the position shown.

The free end of blade segment 16 has a notch 27 for receiving bar 28 on blade segment 18. The free end of blade segment 18 has a notch 29 for receiving bar 26 and blade segment 16. This notching of the blade segments to receive the bar from the other blade segment enable the blade segments 16 and 18 to be disposed in overlapping relationship as shown in Figs. 1 and 2.

The fastener 32 may then be engaged by the tool 10. Fastener 32 (Figs. 3- 5) includes a threaded shank 38 and a head portion 40. The term "fastener" is intended to include studs, machine screws of any thread form, socket head screws, studs and nuts. Provided in the head portion 40 of the fastener 32 is a diametral slot 42 which extends inwardly into the head portion 40 from the exterior surface or top surface, as viewed in Figs. 3-5. At each side of the diametral slot 42 there is provided an undercut chordal slot 44 and 46. The bottom of the diametral slot

42 and the bottoms of the chordal slots preferably lie in a common place oriented generally perpendicular to the longitudinal axis of the fastener 32.

The novel fastener 32 is engaged in a slip proof manner with the tool 10 by moving the sleeve 22 away from the pivot pin 20 (Figs. 1 and 2) as shown in Fig. 3 to enable blade segment 18 to be pivoted outwardly with respect to blade segment 16. Bar 26, which extends transversely on blade segment 16, is engaged in chordal slot 44, which is complementary in shape and size to said bar 26, and the tip of blade segment 16 is seated in the diametral slot, preferably with the tip end of blade segment 16 engaging the bottom of the diametral slot 42 in the head potion 40 of the fastener 32. The blade segment 18 is pivoted back into alignment with blade segment 16 to engage the tip of blade segment 18 in the diametral slot 42 and the bar 28 on blade segment 18, which is complementary in shape and size to undercut chordal slot 46, is engaged within chordal slot 46. The bar 28 extends transversely on blade segment 18. The bars 26 and 28 are preferably of the same size and shape, as are the chordal slots 44 and 46 so that the fastener and tool may be interengaged from either side of the fastener 32. It will be understood that if interchangeability is not needed, or desired for a particular application, it is sufficient for bar 26 be complementary to the chordal slot 44, with which it cooperates, and that bar 28 be complementary to the chordal slot 46, with which it cooperates.

Fig. 6 illustrates the blade 14 fully engaged with the fastener 32, with the transverse bars 26 and 28 in undercut chordal slots 44 and 46, respectively. Sleeve 22 is slid downwardly on the tool 10 toward pivot pin 20 to lock the tool 10 to the fastener 32. Thus, sleeve 22 comprises locking means on the elongated rod 12 for securing the blade segments 16 and 18 together in locked engagement with fastener 32. The blade segments 16 and 18 are complementary to one another and are of the same width and thickness. Basically, they are mirror images of one another. The combined thickness of the blade segments 16 and 18 at their free ends or tips is approximately the same as the width of the diametral slot 42, whereby the free ends of the blade segments may be readily introduced into the end engaged within the diametral slot 42.

The bottoms of chordal slots 44 and 46 lie generally in the same plane as the bottom of the diametral slot 42, as shown in Figs. 5 and 6. Some variation can be accommodated, but for ease of manufacture and use, it is preferred that the slot means comprising the diametral slot 42 and the chordal slots 44 and 46 be formed as shown in Figs. 5 and 6, for example.

The invention can be adapted, as needed to, different size fasteners by constructing the blade 14 and the bars 26 and 28 thereon complementary to the diametral slot and chordal slots in the fastener.

With the blade 14 securely engaged with a fastener 32, the tool 10 can be driven manually or by power in a first direction so as to connect parts, for example, bone in the human body or sheet metal or plastic body components in automotive applications. The tool 10 can also be used to remove the fastener 32 by engaging it and rotating the tool in an opposite direction, either with compressive force or with tensile force. The present invention provides a fastener system that features a firm slip- proof connection between the tool and the fastener. Substantial torque can be applied either manually or by power, without undesirably dislodging the tool from the fastener. The fastener system 30 is safer for the operator or user, since the risk of injury to the operator caused by undesired separation of the tool form the fastener is reduced by a more secure connection between tool 10 and fastener 32.

While I have shown a presently preferred embodiment of the present invention, it will be apparent to persons skilled in the art it may be otherwise embodied within the scope of the appended claims.