Abstract:
A tool, specifically described for a hex wrench, using a split head with the pieces joined by an elastic connector allowing for deformation of the exterior of the head shape to wedge into the hex socket. The split pieces of the head have an exterior profile matching the shape of the socket and the interior split has a cam profile that enhances the wedging action of the tool. The elastic allows for the tool to return to the original shape.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable. 
   REFERENCE TO A MICROFICHE APPENDIX 
   Not Applicable. 
   RESERVATION OF RIGHTS 
   A portion of the disclosure of this patent document contains material which is subject to intellectual property rights such as but not limited to copyright, trademark, and/or trade dress protection. The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records but otherwise reserves all rights whatsoever. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to the field of wrenches. In particular, the present invention relates specifically to a hex wrench using an elastic connection for control of an internal expansion profile for providing a wedge type of engagement. Known art may be found in U.S. Class 81, subclass 436, 439 448; Class 411, Subclass 403 as well as in other classes and subclasses. 
   2. Description of the Known Art 
   As will be appreciated by those skilled in the art, hex wrenches are well known. Patents disclosing information relevant to improved engagement tools include U.S. Pat. No. 785,162, issued to Freytag on Mar. 21, 1905; U.S. Pat. No. 2,455,005, issued to Hall on Nov. 30, 1948; U.S. Pat. No. 3,224,479, issued to Osborn et al. on Dec. 21, 1965; U.S. Pat. No. 3,286,749, issued to Learned on Nov. 22, 1966; U.S. Pat. No. 3,733,937, issued to Mezey on May 22, 1973; U.S. Pat. No. 4,890,521, issued to Bien on Jan. 2, 1990; and U.S. Pat. No. 5,927,165, issued to Vasudeva on Jul. 27, 1999. Each of these patents is hereby expressly incorporated by reference in their entirety. 
   U.S. Pat. No. 3,733,937 issued to Mezey on May 22, 1973 discloses a wrench having a plurality of sides is formed with a head at one end for insertion into a socket of a screw or bolt having a corresponding number of sides. A horizontally springy neck of the wrench is integral with a head and with a tip spaced axially from the head. The tip is offset circumferentially from the head approximately 5° to 10°. A similar head, springy neck and offset tip may be provided at the other end of the wrench. The wrench may be straight or L-shaped and have any number of sides greater than two. 
   U.S. Pat. No. 4,890,521 issued to Bien on Jan. 2, 1990 discloses a power driven screw driver self-gripping composite bit in the form of a pair of mirror image halved elements united at a common oblique interface providing a square end driver for reception in a screw head formed with a combined socket that accepts both a square end bit and a cross-point bit. Each halved element driver portion defines a trapezoidal cross section having major and minor parallel exterior side surfaces, a complete side surface extending at right angles to its major and minor surfaces, and a diagonal-like interface. The composite bit holder resiliently biases the halved elements interfaces into coextensive flush contact normally defining a square end driver. Upon threading torque being applied to the composite bit by a power screw driver the halved elements slip along their interfaces expanding the bit complete side surfaces in opposite directions so as to wedgingly engage their associated socket side faces into positive holding contact obviating slippage of the composite bit square end driver from the combined socket. 
   U.S. Pat. No. 5,927,165 issued to Vasudeva on Jul. 27, 1999 discloses a fastener-driving tool that has a locking insert which expands or displaces to more securely lock the tool in the fastener. The tool has a distal end configured to engage a driving recess in a fastener, and has an annular recess adjacent the distal end, with a reduced cross-section at the annular recess, other than an axial circular cross-section. A locking insert having a generally similar cross-section to that of the distal end is positioned in the annular recess closely around the reduced cross-section. The locking insert may have a split portion which permits expansion of the locking insert when acted upon by the reduced cross-section as a result of rotation of the distal end relative to the locking insert, or may provide locking simply by displacement resulting from being acted upon by the reduced cross-section. 
   Thus, it may be seen that these prior art patents are very limited in their teaching and utilization, and an improved elastic connection hex wrench is needed to overcome these limitations. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to an improved elastic connection hex wrench. In accordance with one exemplary embodiment of the present invention, a hex key device is provided using two sections using a cam action connected by an elastic plug to allow for deformity with return bias to the original position. The cam action provides for an increased pressure and the two section design utilizing different sides of the tool allows for consistent deployment of the wedging action that is absent in prior art designs. 
   The present invention utilizes a first section having an exposed surface defining a portion of an exterior tool shape and an interior portion defining a first expansion profile. This first section is mated with a second section defining an additional portion of the exterior tool shape and an interior portion defining a second expansion profile, the first expansion profile and the second expansion profile adapted to relatively rotate to expand the exterior tool shape and are connected by an elastomeric connector attaching the first section to the second section. The elastomeric connector is a plug inserted into plug apertures in the sections with a cylindrical shape that provides a curved profile adapted to minimize shearing of the plug and a cross section greater than the movement of the two pieces to allow for movement of the sections without shearing of the plug. A handle or bent extension may be added to adapt the invention to the human hand. 
   A method for manufacturing the invention is also taught with the cooling of the cooling the elastomeric plug in order to harden it for insertion into the sections of the tool. 
   The object of the invention is to provide a wedging type of hex wrench or tool which actually works consistently to provide increased fastener gripping to minimize the stripping of connectors or fasteners currently found with known tools. 
   By utilizing two heads that pivot off one another, the dual action hex key creates additional leverage while simultaneously pushing the edges of the hex key further into the corners of the hex bolt to keep the tool from stripping the bolt and/or rounding off the edges of the hex key. The specific cut of the dual heads was selected to facilitate the rotation of the heads to allow the heads to pivot off of one another. The primary purpose of the rubber dowel is to connect and hold the two pieces together. 
   These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent by reviewing the following detailed description of the invention. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views: 
       FIG. 1  is a schematic view of a hex wrench embodying the present invention. 
       FIG. 2  is a schematic view of a hex tool embodying the present invention. 
       FIG. 3  is an exploded perspective view of a hex head embodying the present invention before insertion into a fastener. 
       FIG. 4  is an assembled perspective view of a hex head embodying the present invention before insertion into a fastener. 
       FIG. 5  is a perspective view of the cap on the body in a ready position. 
       FIG. 6  is a perspective view of the cap on the body in an initial offset position. 
       FIG. 7  is a perspective view of the cap on the body in an increased offset position. 
       FIG. 8  is an end view of the cap on the body in a ready position. 
       FIG. 9  is an end view of the cap on the body in an initial offset position. 
       FIG. 10  is an end view of the cap on the body in an increased offset position. 
       FIG. 11  is an end view of the cap on the body in a ready position in a corresponding opening. 
       FIG. 12  is an end view of the cap on the body in an initial offset position in a corresponding opening. 
       FIG. 13  is an end view of the cap on the body in an increased offset position in a corresponding opening. 
       FIG. 14  is a schematic view of a method for manufacturing the device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As shown in  FIGS. 1 through 13  of the drawings, one exemplary embodiment of the present invention is generally shown as a male tool device  200  using a cap section  300  and a base section  400  connected by an elastomeric plug  500 . To understand operation of this invention, an understanding is need of the structure of the female aperture  100  and the device  200 . 
     FIGS. 3 through 4  and  11  through  13  show the operation of the male tool device with a female aperture  100 . It is well understood how a normal hex wrench is inserted into the female aperture and used to turn the corresponding fastener or structure. The present invention is used similarly, although the actual contact between the male tool device  200  and the aperture side surface  110  is changed. The female aperture  100  is shown with an aperture shape  102  of a hexagon  104  as a standard shape used in industry. The drawings show that the aperture  100  has an aperture width  106  and aperture depth  108  defining an aperture side surface  110 . The aperture side surface  110  for the hexagon shape includes a first aperture wall  112 , a second first aperture wall  114 , a third aperture wall  116 , a fourth aperture wall  118 , a fifth aperture wall  120 , and a sixth aperture wall  122 . with this definition of the aperture, a corresponding understanding is needed of the structure of the male tool device  200 . 
   The male tool device  200  is shown in the preferred embodiment of a six sided hexagon  202  with the device  200  using a cap section  300  connected to a base section  400  by an elastomeric plug  500 . The preferred material is a tool steel following ASTM A681 Type S-2 (UNS#41902) which is available in the hexagonal shape. This steel may be water hardened to an appropriate hardness such as a 59-60 Hardness Rockwell C. 
   The cap section  300  includes a cap front face  302  and an exposed surface  304  defining an exterior tool shape  306 . In the preferred embodiment, the cap portion of the exterior tool shape for the hexagon includes a first side  308 , a second side  310 , and a third side  312 . The cap has a cap rear face  314  on the inward side of the device  200  with a cap interior portion  316  defining a cap expansion profile  318  along the cap length  320  that is used to create the cam effect for the invention. The cap also defines a cap plug aperture  322  having a cap aperture diameter  324  and a cap aperture depth  326 . For the preferred embodiment, the cap aperture depth  326  passes all the way through the cap  300 . 
   The cap  300  is mounted onto a base section  400  having a base front face  402  and a base exposed surface  404  defining an exterior base shape  406 . For the hexagon shape, the exterior base shape  406  includes a fourth side  408 , a fifth side  410 , and a sixth side  412 . The inner portion of the base section  400  includes a base cliff face  414  and a base interior portion  416  defining a base expansion profile  418  along the base interior length  420  for use with the cap expansion profile  318 . The base also includes a base plug aperture  422  having a base aperture diameter  424  with a base aperture depth  426 . 
   The elastomeric plug  500  is inserted into the cap plug aperture  322  and the base plug aperture  422  to connect the cap  300  to the base  400 . The primary purpose of the plug  500  is to connect the two sections together. The plug  500  must be flexible enough to allow the heads to rotate in relation to each other while being strong enough to withstand the stress during use. Recommended materials are rubber, TEFLON a trademarked product by DUPONT of Wilmington, Del., nylon, flexible acrylics, and silicon although other materials should also be considered based on design characteristics and cost. The plug  500  has a cylindrical body  502  defining a curved profile  504  which spreads shearing forces over a broad area to help minimize the possibility of shearing of the elastomer. The plug  500  defines a circular cross section  506  having a plug diameter  508  that is chosen to be greater than the expected movement of the cap  300  in relation to the base  400 . This size choice allows for the movement of the cap  300  in relation to the base  400  for a distance  512  without the shearing of the elastomeric plug  500  during normal use. The plug is designed with a plug length  510  associated with the cap plug aperture  322  and the base plug aperture  422  in order to provide sufficient friction to retain the plug in both apertures  322 ,  422  during normal use. 
     FIGS. 1 and 2  shown how a handle  514  may be added to the device using convention construction techniques or a gripping arm may be made using a bent extension  516  to form an L-shape  518 . 
     FIG. 14  is a schematic view of a method for manufacturing the device  200 . Construction of the device  200  is made using a cooled elastomer method  600  which begins with providing  602  the requisite cap section  300 , base section  400 , and elastomeric plug  500 . The cap section  300  and base section  400  may be formed by impact forming, machine forming, or simply cutting  604  a hex shaped rod or other appropriate tool shape. The gripping handle may be formed by simply bending  612  the hex shaped rod. Next, the process continues by cooling  606  the elastomeric plug  500  to increase its rigidity to allow for inserting  608  of the plug  500  into the apertures  322 ,  422  without significant deformation. The process continues by increasing  610  the plug  500  temperature to an operating temperature to return it to its elastic state. 
   Reference numerals used throughout the detailed description and the drawings correspond to the following elements:
         a female aperture  100     an aperture shape  102     hexagon  104     aperture size  106     aperture depth  108     aperture side wall  110     first aperture wall  112     second aperture wall  114     third aperture wall  116     fourth aperture wall  118     fifth aperture wall  120     sixth aperture wall  122     A male tool device  200     a six sided hexagon  202     a cap section  300     a cap front face  302     an exposed surface  304     an exterior tool shape  306     first side  308     second side  310     third side  312     a cap rear face  314     a cap interior portion  316     a cap expansion profile  318     a cap length  320     a cap plug aperture  322     a cap aperture diameter  324     a cap aperture depth  326     a base section  400     a base front face  402     a base exposed surface  404     an exterior base shape  406     fourth side  408     fifth side  410     sixth side  412     a base cliff face  414     a base interior portion  416     a base expansion profile  418     a base interior length  420     a base plug aperture  422     a base aperture diameter  424     a base aperture depth  426     an elastomeric plug  500     a cylindrical body  502     a curved profile  504     a circular cross section  506     a plug diameter  508     a plug length  510     a distance  512     a handle  514     a bent extension  516     an L-shape  518     method  600     providing  602     cutting  604     cooling  606     inserting  608     increasing  610     bending  612         

   From the foregoing, it will be seen that this invention well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure. It will also be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Many possible embodiments may be made of the invention without departing from the scope thereof. Therefore, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.