Abstract:
There is described and claimed herein a noback bolt design which comprises an elongated shaft having two opposing ends. The first end has an enlarged conical bolt head that extends from this shaft. On the opposite shaft end is a terminus or tip. Between the tip and the conical head, the shaft bears an externally threaded segment on at least a portion of the shaft. The precise length of this segment is determined upon intended applications of my bolt, and the type or exact number of structural components to be assembled. These components include panels, brackets, planar surfaces, chassises, and like structures.

Description:
GOVERNMENT INTEREST 
   The invention described herein may be made, used, and licensed by, or for, the United States Government for governmental purposes without paying any royalty. 

   BACKGROUND AND SUMMARY 
   The present invention generally relates to fasteners, such as a screw or bolt, which hold together one or more structural components in a strong, secured fashion. In another aspect, it also relates to non-removable or tamper-resistant fasteners. A special driving tool is also provided herein for the advancement of said fastener into said components. 
   Described herein is my noback bolt design comprising an elongated shaft having two opposing ends. The first end has an enlarged conical bolt head that extends from this shaft. On the opposite shaft end is a terminus or tip. Between the tip and the conical head, the shaft bears an externally threaded segment on at least a portion of the shaft. The precise length of this segment is determined upon intended applications of my bolt, and the type or exact number of structural components to be assembled. These components include panels, brackets, planar surfaces, chassises, and like structures. 
   The absence of a standard tool engaging surface on this conical head deters tampering or removal by traditional tools. Furthermore, this bolt is readily installed within one or more structural components to complete an assembly of constructs or workpieces with my aforementioned tool. However, once my noback bolt achieves a predetermined level of tightness, it is not readily removed without extraordinary efforts. Moreover, the noback bolt assures that a strong, mechanical bond or interlock is maintained in all assembled constructs or workpieces. Preferably, at least one of the components being joined together will have a compatible, internally threaded aperture or blind bore for acceptance of the threaded segment of my bolt. Also, at least one component must have a firm bearing surface upon which the underside of my bolt head will ultimately rest. 
   In the prior art, an ordinary bolt comprises an elongated, externally threaded shaft that longitudinally extends from a hex- or slot-shaped head. Such a bolt is usually positioned in a structural member by simply turning or rotating the head with a standard wrench or screwdriver in either a clockwise, or counterclockwise, direction depending on whether said bolt is being tightened or loosened, respectively. 
   In sharp contrast, my noback bolt is intended to turn in only a single direction (clockwise) and that is for the sole purpose of tightening said bolt against one or more structural components to make a completed assembly. Thus, for all practical purposes, an installed noback bolt is not removable and the joined constructs or workpieces are permanent. Examples of typical applications include plates of uparmor which can be added to legacy military vehicles to either modernize or upgrade their utility and missions. Similar applications exist within the appliance, automotive, aviation, and related industries of mass production, which prefer, or even mandate, nearly permanent or tamper resistant constructs for safety reasons. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a front view of a first embodiment of my noback bolt. 
       FIG. 2  is a top view of FIG.  1 . 
       FIG. 3  is a front view of a second embodiment of my noback bolt. 
       FIG. 4  is a top view of FIG.  3 . 
       FIG. 5  is a perspective view of  FIG. 1  showing the concave underside of the head of FIG.  1 . 
       FIG. 6  is an exploded front view in partial section, of my special tool engaging the noback bolt of FIG.  3 . 
       FIG. 7  is a top view of my special driving tool. 
   

   DETAILED DESCRIPTION 
   In the drawings, two equally satisfactory embodiments  10 ,  40  of my invention are depicted.  FIG. 1  shows a first embodiment  10  of my noback bolt in side elevation with a single arcuate slot  12  contained within an enlarged, conical bolt head  16 . Extending from the underside  18  of said head is an elongated shaft  20  that terminates at a tip  22  distal from the head. This shaft has a common central axis  24  with the apex  26  of the conical bolt head. At least a part of said elongated shaft  20  bears external threads  28  thereon. Depending on a specific application or need, the threads on this elongated shaft may extend for the full length of the shaft. Moreover, the shapes or sizes of the noback bolt may be of varying lengths and diameters. Further, while a coarse thread is depicted in  FIG. 1 ; it could just as easily be a fine thread based upon the type of final assembly in which it is employed.  FIG. 2  is a top view of the conical bolt  10  of  FIG. 1  with a singular slot  12  embedded within the conical surface  14 . 
     FIG. 5  is a view in perspective showing a scooped-out underside  18  of the conical bolt head  16  of  FIG. 1  in greater detail. While not shown, my second embodiment  40  has a similar underside  48  in its bolt head  46 . With specific reference to  FIGS. 1 ,  3 , and  5 , the bolt heads  16  and  46  have a concave undersurface  18  or  48  that provides an extremely tight and secure joint between the bolt and the construct(s) or workpiece(s) whenever a bolt is tightly torqued into an assembled or installed position. The benefits of this design is further exemplified in my  FIG. 6  wherein an assembly of two representative structural elements  32  (a panel having a threaded or unthreaded aperture) and  34  (a planar surface having a blind, internally threaded bore) are depicted using my noback bolt. When installed, the underside of my bolt head will preclude any attempt to loosen or remove it by either prying or lifting on said bolt head. In fact, this bolt will tightly abut, or even bite into, the surface of the top bearing surface of structural panel  32 . 
     FIGS. 3 and 4  depict a double slotted embodiment  40  of my invention which is comprised of two, equally spaced apart arcuate slots  42 . Each of my embodiments  10 ,  40  has a cone-shaped head  16 ,  46  that is designed to prevent gripping of the conical surfaces  14 ,  44  with ordinary tools, or by the use of traditional gripper tools like a pipe wrench or pliers. Further, these heads may be treated by any of the conventional processes known to the art which will additionally enhance and/or harden these surfaces to preclude the potential for scratching, marring, and/or gripping of these bolt heads  16 ,  46 . 
   The sole means for tightening my noback bolt is generally shown in  FIGS. 6 and 7  which are depictions of my driving tool  70 . This tool appears therein as a standard, socket-like device that can be manufactured by conventional methods, such as machining, stamping, or casting. This tool is readily used with an ordinary socket wrench, ratchet, or driver which has a dimensionally compatible square-drive that fits within a first drive means  72  on top of my tool  70 . This tool can also be further modified with the permanent, or detachable, addition of a “T” or “L” shaped handle. In these latter configurations, the modified tool will resemble a spark-plug wrench or a tire iron, respectively. 
   Generally, my tool  70  has an internal conical cavity  76  that begins as a central bore a short distance at its bottom, and then extends to a point remote from the top and near the first drive means  72 . This cavity  76  is dimensionally sized and shaped to receive, and then conform with, the exterior conical surface of bolt head(s)  16 ,  46 . Upon initial contact with a bolt head, the tool&#39;s second drive means  78  will engage the exterior conical surface(s)  14 ,  44  of said bolt, and then move directly away from the apex(es)  26 ,  56 . After the tool&#39;s second drive means  78  engage the arcuate slot(s)  12 ,  42  within the heads of my noback bolts, said heads are easily advanced into the structural components  32 ,  34  to form a completed installation or assembly. Thereby, a mating engagement of the driving tool  70  with the slots  12 ,  42  and conical bolt heads  16 ,  46  will allow the manual application of sufficient forces to controllably position, install, and advance the bolt to perform work (rotation of said bolts) in a tightening direction. 
   In a preferred embodiment, my tool&#39;s second drive means  78  comprises two projections within the conical cavity  76  of my tool  70 , which are interiorty positioned within bore(s)  74 , equally spaced-apart, and spring-loaded or spring-biased. These spring-actuated projections are preferably selected from inserts, posts, pins, or detents that will readily deploy into arcuate slot(s)  12 ,  42  of the conical bolt head(s)  16 ,  46  when my tool  70  is placed over said bolts and rotated. As this version of my tool slides over the conical bolt head, the detents or posts will be initially forced back by the smooth, conical surface of the bolt head. As the tool  70  is then turned in the tightening direction at its fully seated depth on said bolt, these projections will fully engage the arcuate slot(s) of the bolt head and will rotate to a maximum slot depth until the land(s) or shoulder(s)  30 ,  60  are contacted. Thusly positioned, the subsequent rotating of this tool  70  will result in a desired degree of tightening of the bolt head to the surfaces of the workpiece(s) to be joined together by my noback bolt. Because the slots  12 ,  42 , in the bolt heads  16 ,  46 , are offset from the cone apexes  26 ,  56 , and from the common axis(es)  24 ,  54  of both the conical head and the bolt shaft, the projections  78  of my preferred tool must be spring-actuated to accomplish their desired function. Those skilled in the art are familiar with acceptable substitutes and equivalents. 
   Referring back to  FIG. 2  or  4 , an arcuate slot  12  or  42  is essentially a semicircular element in design. It is generally offset from the apex  26  or  56 , offset from the common axis  24  or  54  of the bolt head  16  or  46 , and offset from the bolt shafts  20 ,  50 , respectively, of my noback bolts. Moreover, the depth of these slots in my bolt(s) gradually increases from zero Z at the conical surface(s)  14  or  44  to a maximum depth at a point along the conical surface of about 180 degrees while traveling in a clockwise direction. At the termination T of the slot(s), and at their maximum width and depth, a land or shoulder  30  or  60  is provided therein for interfacing with both my special tool  70  and preferred drive means  78  for driving the conical bolt head. The internal surface(s) of the arcuate slots  12 ,  42  are also curved to provide a smooth and gradual transition from the exterior, conical surface(s)  14 ,  44  at the point Z of my noback bolt head to a maximum width and depth T at the land(s)  30  or  60 . This unique feature of the slots also precludes the application and use of my driving tool  70  in the reverse (loosening) direction. 
   I wish it understood that I do not desire to be limited to the exact details of construction or method shown herein since obvious modifications will occur to those skilled in the relevant arts without departing from the spirit and scope of the following claims.