Patent Publication Number: US-2005115041-A1

Title: Fastener starting tool

Description:
FIELD OF INVENTION  
      This invention relates generally to an apparatus and method for starting and installing fasteners. This invention relates particularly to an apparatus that provides a means to securely hold a fastener until the fastener is securely started in the desired aperture or location. More particularly, this invention provides a means to securely start a roll pin fastener into an aperture without the pin dropping prior to it being fully seated.  
     BACKGROUND  
      Fastener installation can be a tedious and frustrating task. This is especially true if the fastener is small and the desired location of the aperture for the fastener is in a confined space or is difficult to reach. The installation of roll pin fasteners in the automotive industry and firearm assembly are examples of this tedious task.  
      A roll pin is fastener that comprises a hollow tube of metal cut longitudinally along the length of the tube, thereby forming a “C”-shaped cross section. The roll pin is driven into a hole of slightly smaller diameter, causing the edges of the cut to compress against each other, so that the resulting cross-section is a complete circle. Roll pins come in various sizes, typically less than 1 inch in diameter.  
      Roll pins are used to assemble firearms, industrial, automotive, or other heavy equipment, and other solid articles. The pins are often used in cramped spaces that are difficult to reach. To seat a roll pin with traditional tools, the user balances the pin on the convex end of a roll pin punch and delicately slides one end of the roll pin into the hole. The end of the punch is then tapped with a hammer until the pin is driven far enough into the hole to remain in place until it can be fully driven into the hole with another tool. Alternatively, the user uses needle-nose pliers to grasp the pin and insert it into the hole, and the pin is hammered directly until fully seated.  
      Because the roll pins are so tiny and the placement so difficult, pins are often dropped before they can be seated in place, causing repeated trial-and-effort to get the pin seated. This is very frustrating to the user, and time-consuming too.  
      The prior art is replete with inventions designed to solve the problem of holding a fastener securely for easy placement. Many of these devices utilize variations of pincher arms to hold the fastener. See, for example, Suga, U.S. Pat. No. 4,363,250; Duffee U.S. Pat. No. 4,856,697; and O. Haas, U.S. Pat. No. 2,360,054. Other inventions use various compressive means to hold the fasteners in place. For example, in U.S. Pat. No. 3,788,537, Fox discloses the use of an o-ring or u-shaped spring to hold the fastener in the tool and in U.S. Pat. No. 4,709,841, Wollar lines a hollow bore with compressible rubber. Others have developed magnetic tools, such as Hitoshi, Japanese Publication No. 07164346; A, Stillwagon, U.S. Pat. No. 3,392,767; and Eggert et al. U.S. Pat. No. 5,603,248. However, these devices have complicated structures for holding the fasteners, and none provide a simple solution that is easy to use and relatively inexpensive to manufacture. Consequently, none of these devices have met with significant commercial success.  
      The placement and installation of other fasteners, such as shear pins, upholstery nails, or weatherstrip nails, for example, can be just as tedious and frustrating. Therefore, there is a need to provide an improved tool and method to aid the installation of fasteners.  
      Therefore, it is an object of this invention to provide an apparatus that eliminates the dropping of fasteners prior to placement. It is another object of this invention to minimize repeated attempts to start fasteners, providing more efficient and effortless placement of fasteners. It is a further object to provide a tool for holding fasteners that is simple to make and use.  
     SUMMARY OF THE INVENTION  
      The present invention is a tool that makes fastener placement effortless by providing a secure way to hold the fastener until it is started in the desired aperture or location. More specifically, the present invention makes roll pin fastener placement and installation more efficient by providing a secure way to hold and start the roll pin in the desired aperture.  
      The device is a hollow-end fastener starting tool. The inside diameter of the hollow-end is slightly larger than the outside diameter of the fastener. To insert a fastener, a small dab of a tacky substance is applied to the end of the fastener, and the tacky end is inserted into the hollow end of the tool. The tacky substance holds the fastener in place inside the tool. In the preferred embodiment, the fastener is a roll pin. Wheel bearing grease is applied to one end of the roll pin and the tacky end is then inserted into the hollow end of the tool. The roll pin is then inserted into a desired hole, and the user hammers the end of the starting tool, starting the roll pin into the hole. Once started, the friction holding the fastener in place is greater than the friction holding the tacky end in the tool, so the starting tool can just be pulled away from the fastener, leaving the fastener in place to be fully seated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of an embodiment of the present invention.  
       FIG. 2  is a perspective view of the roll pin fastener.  
       FIG. 3  is an enlarged, cut-away perspective view of the distal end portion of the embodiment of  FIG. 1 .  
       FIG. 4  is a cross-sectional view of the embodiment of  FIG. 1  along the lengthwise axis.  
       FIG. 5  is a side elevational view of the tool of  FIG. 1 .  
       FIG. 6  is a cross-sectional view of the distal end of the tool of  FIG. 1 .  
       FIG. 7  is an illustration of the application of the present invention, in partial cross-section.  
       FIG. 8  is a perspective view of an alternate embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      This invention is an apparatus and method for more efficiently starting fasteners in apertures or desired locations. Referring to  FIGS. 1 through 7 , there is illustrated the preferred embodiment of the present invention generally designated as starting tool  100  which is used to seat roll pin  102  in a desired aperture  124 . As shown in  FIG. 1 , roll pin  102  is placed in the bore  110  of starting tool  100  and then started in the desired location by the user  150 . Prior to placing roll pin  102  into bore  110 , the user  150  applies an amount of a tacky substance  112  on an end of roll pin  102 , as shown in  FIG. 2 . The user  150  then places the tacky end of the fastener  114  into the bore  110  of starting tool  100 , as shown in  FIG. 3 . Alternatively, the tacky substance  112  could be placed in the bore instead of on the fastener itself. The use of the tacky substance  112  in combination with the size and shape of bore  110  allows the user  150  to more efficiently retain the fastener in the bore prior to seating the roll pin  102  into the desired location or aperture  124 .  
      In the preferred embodiment of the invention starting tool  100  is a shaft  104 , having a distal end portion  106  and a proximal end portion  108 . As shown in  FIGS. 1 and 3 , bore  110  is located in the distal end portion of the shaft  106 . The bore  110 , in the preferred embodiment, is axial along the distal end portion of the shaft  106  and is shaped and sized to accommodate a roll pin  102 , as shown. The size and placement of the bore  110  may vary, depending on the type of fastener being started. For example, the bore may be quite shallow for optimizing use with fasteners with heads, such as upholstery nails or brads. Longer and heavier fasteners may require a deeper bore. The width of the bore may also vary depending on the type and width of fastener being seated.  
      The proximal end portion of the shaft  108  is used to aid the user  150  in holding or gripping the starting tool  100  during use, thus, in this embodiment, the proximal end portion of the shaft  108  is larger in diameter than the distal end portion of the shaft  106 . More specifically, as shown in  FIGS. 5 and 6  of the preferred embodiment of this invention for placing a roll pin of about {fraction (3/16)} inch diameter in an automotive transmission, the dimensions of the distal end portion of the shaft  106  and proximal end portion of the shaft  108  are: distal end portion of the shaft diameter E is about {fraction (13/32)} inches; distal end portion of the shaft length G is about 2 and {fraction (7/16)} inches; proximal end portion of the shaft diameter F is about {fraction (5/8)} inches; proximal end portion of the shaft length H is about 3 and {fraction (1/8)} inches. To better enable the user&#39;s  150  hold or grip on the starting tool  100 , cross-cut knurls  118 , as shown in  FIG. 1 , are machined onto the proximal end portion of the shaft  108 .  
      In the preferred embodiment of the invention, the shaft  104 , is made of metal and is substantially cylindrical in shape. Under appropriate circumstances, such as use of varied fastener types or applications, the shaft  104  may be made from a material other than metal, such as wood, plastic, or some other application appropriate material. Additionally, the size and shape of the distal end portion of the shaft  106  and the proximal end portion of the shaft  108  may vary depending on fastener type or application. For example, under appropriate circumstances, it may be desirable to have a bend in the distal portion of the shaft  106  to aid in placement of the fastener, or the bore may be made at an angle to the axis of the shaft, as illustrated in  FIG. 8 .  
      As previously discussed, the shape and size of bore  110  is specific to the type of fastener in use. The roll pin  102  used in the preferred embodiment of this invention is a roll pin fastener. As shown in  FIG. 2 , the roll pin  102  has a fastener length A of about {fraction (13/16)} inches and a fastener outside diameter B of about {fraction (3/16)} inches. The bore  110  of the preferred embodiment of this invention, as shown in  FIGS. 3 and 6 , for use with the described roll pin  102 , is substantially circular with a bore length C of about {fraction (1/4)} inches bore diameter D of about {fraction (7/32)} inches. The dimensions of the bore  110  combined with the use of the tacky substance  112  on the tacky end of the fastener  114  provide a sufficient amount of friction to hold the fastener in starting tool  100  for starting of the fastener into the desired location or aperture  124 .  
      The end  116  of the proximal end portion of the shaft  108  of the preferred embodiment of this invention, as shown in  FIGS. 5 and 7 , is substantially flat. As shown in  FIG. 7 , this allows the user  150  to fully tap the end  116  with a hammer  122  or other blunt object, as necessary, forcing the roll pin  102  into the desired aperture  124  or object  120 . Because the roll pin nature is to be crushed into a smaller diameter when forced into an aperture, the end of the bore  103  that is inside the shaft  104  should also be substantially flat. This will prevent the fastener from becoming stuck inside the shaft when the tool is tapped. Once the roll pin  102  is started in the desired aperture  124 , the resulting compression and force (friction) on the roll pin  102  by the aperture  124  is greater than that provided by the tacky substance  112  and bore  110 , thus permitting the user  150  to remove the starting tool  100  from the proximity of the roll pin  102 , while having the roll pin retained in the aperture  124 , and allowing completion of the seating of the roll pin. The tacky substance  112  used in the preferred embodiment of this invention is wheel bearing grease. However, under appropriate circumstances, the tacky substance  112  may be some other substance of varying viscosity, for example petroleum jelly, oil, adhesive, or the like, depending on the application. The more tacky a substance is, the more the substance tends to resist releasing the fastener or the heavier a fastener it can retain. Therefore, a more tacky substance may be required when using a larger fastener and a less tacky substance when using a smaller fastener.  
      An alternative embodiment of the invention is shown in  FIG. 8 . The fastener starting tool  700 , as shown, is for starting a shear pin fastener  702 . As shown, the starting tool shaft  704  is rectangular in shape with the bore  710  non-axial along the shaft  704  from the distal end of the shaft  706 . Under appropriate circumstances, the shape of the shaft  704  and bore  710  may vary, for example, it may be desirable to have a hexagonal shape shaft  704  for holding purposes or a hexagonal shape bore  710  because of the shape of the fastener. Additionally, the placement of the bore  710  within the shaft  704  may vary; it may be axial or non-axial depending on the application or type of fastener in use.  
      While there has been illustrated and described what is at present considered to be the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the true scope of the invention. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.