Abstract:
A spline drive fastener system involves a fastener wherein a drive engagement surface is formed in the head of the fastener. The drive engagement surface includes eight separate points of engagement. The points of engagement are arranged on eight radial slots formed by the central axis of the fastener head. A method of forming the drive engagement surface comprises forcing a punch against a fastener workpiece to form at least eight radial slots.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the priority of U.S. Application No. 60/630,451 filed on Nov. 23, 2004. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates generally to fasteners used in the construction arts, and in particular, to fasteners having drive surfaces.  
       BACKGROUND OF THE INVENTION  
       [0003]     Commercial and residential structures are typically constructed with a variety of fastener types. Typically these fasteners have a head configured to receive a tool for the purpose of allowing the fastener to be driven into an appropriate substrate. Conventionally, the tool receiving portion of the fastener head includes recessed areas which form slots or cavities. The slots are generally either a single slot, formed across the surface of the head, or a pair of intersecting slots which form a cross. In some cases, the fastener head includes a cavity in the form of a square.  
         [0004]     Conventionally, a tool having a complementary shape to portions of the fastener head is used to engage the fastener recess. Once received by the recess, the fastener can then be rotated, or otherwise manipulated by the tool, such that the fastener is driven into the material to be secured.  
         [0005]     The conventional fastener head and driving tool arrangement suffers from several drawbacks. For example, fasteners are often installed using a tool fitted to a power driver device, such as, an electric drill. This power driven device/tool/fastener combination must be maintained in precise alignment wherein the central axis of the fastener and the central axis of the tool are in angular alignment. In addition, pressure must be applied on the power driver device in order to keep the tool engaged with the fastener and to prevent the tool from “camming out” of the fastener. Typically, if the tool and fastener become misaligned and/or if pressure is not applied to the power driven device, the tool and the fastener head can become fully or partially disengaged. Disengagement is often facilitated by the configuration of the fastener head and tool interface. For instance, the slotted or cross slotted fastener heads often have a configuration that acts to separate the head from the tool. Often the head configuration includes an inclined ramp that allows the contact surfaces of the tool to disengage from the head. The disengagement process can result in the fastener head being stripped or damaged such that the fastener cannot be either driven further into the substrate or be removed from the substrate. In addition, the disengagement often results in the tool suddenly losing contact with the fastener such that the tool user cannot maintain control of the tool and/or associated driving device.  
         [0006]     The environments in which the fasteners are deployed often exacerbate the above discussed drawbacks. For example, during construction, fasteners are often required to be used on portions of a structure which are not readily accessible. These structural portions may be positioned in an elevated, partially occluded, overhead, and/or in an orientation relative to the fastener installer such that the tool/fastener alignment as well as the pressure between the tool and fastener cannot be consistently maintained. For example, when a tool user is positioned on a ladder or scaffold in order to drive a fastener, the user often has to apply pressure on the tool driver with an arm that is extended laterally away from the body center. At the same time, the user must take care to remain in a stable and balanced position. This situation prevents a typical user from being able to apply as much force on the power driver as would be possible if the arm alignment was directly in front of the body center. This often results in the fastener head being stripped and/or the tool becoming disengaged with the fastener. When this disengagement occurs rapidly, the tool user often must quickly react in order to maintain stability to prevent falling from the ladder or scaffold.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention in a preferred form is directed to a fastener having a torque receiving head with an engagement surface that includes at least eight separate points of engagement. The points of engagement are arranged on eight radial slots formed about a central axis of the fastener head. The eight radial slots may have wall portions which collectively define a substantially square opening. The substantially square opening may provide an engagement location for a square bit tool. The radial slots may also have angled wall portions, wherein a portion of the wall has an angle defined between a lower portion of the wall and a top portion of the wall and which is relative to the central axis of the fastener head. The radial slots may be formed about the central axis of the fastener head such that each of the eight radial slots about the center axis have a center line, wherein each radial slot center line is indexed at an approximately 45° angle from an adjacent center plane. The positioning of the radial slots may allow tools of differing configurations to be used.  
         [0008]     An object of the present invention is to provide a strong contact interface between the engagement portion of the fastener head and the driver tool during installation of the fastener.  
         [0009]     An object of the invention is to provide a fastener with drive engagement surface which can be used with a variety of driver bits or fastener driver tools.  
         [0010]     An object of the invention is to provide a method of forming a drive engagement surface with a die which provides a strong contact interface between the drive engagement portion of the fastener head and the driver tool during installation of the fastener.  
         [0011]     A further object of the invention is to provide a fastener with a drive engagement surface which provides safe, efficient, and effective engagement with a driver tool. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     Other objects and advantages of the invention will be evident to one of ordinary skill in the art from the following detailed description with reference to the accompanying drawings in which:  
         [0013]      FIG. 1A  shows a portion of a fastener engagement surface having radial slots which define a square opening consistent with the present invention;  
         [0014]      FIG. 1B  is a top view of a fastener head that includes a fastener engagement surface having radial slots which define a square opening consistent with the present invention;  
         [0015]      FIG. 2A  shows a portion of a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0016]      FIG. 2B  is a top view of a fastener head that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention.  
         [0017]      FIG. 3A  shows a portion of a fastener head of a drill type fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0018]      FIG. 3B  shows a portion of a drill type fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0019]      FIG. 4A  shows a portion of a fastener head of a panel fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0020]      FIG. 4B  shows a portion of a panel fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0021]      FIG. 5A  shows a portion of a fastener head of a roofing type fastener with a drill-point and a truss head that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0022]      FIG. 5B  shows a portion of a roofing type fastener with a drill-point and a truss head that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0023]      FIG. 6A  shows a portion of a fastener head of a plastic lumber fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0024]      FIG. 6B  shows a portion of a plastic lumber fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0025]      FIG. 7A  shows a portion of a fastener head of a gutter fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0026]      FIG. 7B  shows a portion of a gutter fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0027]      FIG. 8A  shows a portion of a fastener head of an engineered wood fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0028]      FIG. 8B  shows a portion of an engineered wood fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0029]      FIG. 9A  shows a portion of a fastener head of a ledger board fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0030]      FIG. 9B  shows a portion of a ledger board fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0031]      FIGS. 10A-10C  respectively show side perspective, front end, and side views of a fastener engagement tool consistent with the present invention;  
         [0032]      FIG. 11  shows a portion of a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention;  
         [0033]      FIG. 12A  is a side view of a fastener engagement surface forming punch surfaces consistent with the present invention;  
         [0034]      FIG. 12B  is an enlarged side view of the fastener engagement surface forming punch of  FIG. 12A  showing the angled shoulder consistent with the present invention;  
         [0035]      FIG. 13  is an enlarged top view of the fastener engagement surface forming punch of  FIG. 12A  showing the angled shoulder consistent with the present invention;  
         [0036]      FIG. 14A  shows a portion of a fastener head of a wood insulation screw fastener that includes a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention; and  
         [0037]      FIG. 14B  shows a portion of a wood insulation screw fastener that includes a head with a fastener engagement surface having radial slots which define tool engagement surfaces consistent with the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0038]     With reference to the drawings wherein like numerals represent like parts throughout the several figures, a fastener engagement surface formed in the head of a fastener in accordance with the present invention is generally designated by the numeral  10 . The fastener engagement surface  10  includes, as partially shown in  FIG. 1A  and as shown in  FIG. 1B , the walls of at least eight radial slots  12  spaced about a center axis  14  of the engagement surface  10 .  
         [0039]     In one embodiment of the present invention, each radial slot  12  includes a rear wall  16 , a first side wall  18 , and a second side wall  20 . A radial slot center plane  17  extends from the center axis  14  of the engagement surface  10  through a point substantially equidistant from the positions where the rear wall  16  and the first side wall  18  intersect, and where the rear wall and the second side wall  20  intersect. The first side wall  18  of a first radial slot  12  and the second side wall  20  of a second adjacent radial slot  12  includes a transition portion  22 . The transition portion  22  extends between adjacent radial slots  12 .  
         [0040]     In one embodiment of the present invention, the first side wall  18  and second side wall  20  may be angled relative to the radial slot center plane  17 . For example, an angle, shown in  FIG. 1A  as “b”, may be approximately 0° to approximately 4°, with a preferred angle being approximately 3°. The angle b, among other things, operates to enhance contact between the side wall and a drive tool  60  ( FIGS. 10A-10C ) and thus engagement with the engagement surface  10 . For example, the tool may have features which are configured to be complementary to the angled side walls ( 16 ,  18 ) such that a close mechanical relationship is formed between the side walls ( 16 ,  18 ) and the tool features. This can reduce or prevent such things as slippage between the tool  60  and the engagement surface  10  and/or stripping of the engagement surface  10 . The angled side wall may allow the engagement surface  10  to be connected to the tool such that a fastener essentially forms an extension of the tool. For example, the tool can be inserted into the engagement surface and the tool and fastener assembly can be moved as a unit to a site of installation.  
         [0041]     In one embodiment of the present invention, portions of the radial slots  12  form an opening  24  which can be used to accept a fastener engagement tool  60 . For example, as shown in  FIGS. 1A and 1B , the relative positioning of the radial slots  12  and the transition portions  22  define a socket  24  which is substantially square in shape. It should be understood that, even though a socket  24  configured to receive a fastener driver tool is present, a fastener driver tool can also be used which has projections that operatively engage with some or all the radial slots  12 .  
         [0042]     In one embodiment of the present invention, as shown in  FIGS. 2A and 2B , the opening  24   a  of the fastener tool engagement surface  10   a  can be substantially round.  
         [0043]     In one embodiment of the present invention, as shown in  FIG. 3B , the engagement surface  10   a  has an upper portion  26  and a lower portion  28 . As shown in  FIG. 2A , the rear wall  16  and side walls  18 ,  20  of the radial slot  12  have portions which are angled relative to an axis “x” that extends through the central axis  14  of the engagement surface  10   a . The angle of portions of the rear wall  16  and side walls  18 ,  20  may be in a range of between about 0° and about 5°. Preferably the angle is about 3° to about 4°. For example, portions of the rear wall  16  are angled such that a portion of the rear wall proximate the lower portion  28  is positioned closer to the axis “x” than a portion of the rear wall  16  proximate the upper portion  26 . The angle of the rear wall  16  thus forms a bevel  30 . The bevel  30  formed by the angle of the rear wall  16  and the side walls  18 ,  20 , among other things, advantageously facilitates the insertion of the tool into the engagement surface  10   a.    
         [0044]     In one embodiment of the present invention, as shown in  FIG. 1A , each radial slot  12  may be positioned such that the radial slot center plane  17  of adjacent radial slots  12  are indexed about the center axis  14  in 45°increments. For example, as shown in  FIG. 1B , for a fastener engagement surface  10  having eight radial slots, the radial slots would be at the 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°positions relative to the center axis  14 . As shown in  FIG. 2B , line “e” extends through radial slots  12  at the 0° and 180° positions, and line “f” extends through the radial slots  12  at the 90° and 270° positions. A tool can be utilized which, for example, engages with radial slots  12  at the 0° and 180° positions and/or radial slots  12  at the 90° and 270° positions. A tool can also be utilized which, for example, engages with radial slots  12  at any two or more of the 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° positions.  
         [0045]     As shown in  FIGS. 3A and 3B , in one embodiment of the present invention, a fastener  40  may be used which has a head  32  with a fastener engagement surface  10   a . The fastener  40  may be used for wood fastening and includes a drill type point  42  with a threaded region  44  proximate the drill type point  42 .  
         [0046]     As shown in  FIGS. 4A and 4B , in one embodiment of the present invention, a fastener  40   a  may be used which has a head  32   a  with a fastener engagement surface  10   a . The fastener  40   a  may be used for fastening panel material and includes a fast entry type point  42   a  with a threaded region  44   a  proximate the fast entry type point  42   a.    
         [0047]     In  FIGS. 3B and 4B , the underside of the head uniformly tapers toward the shaft at a preferred angle of 40°.  
         [0048]     As shown in  FIGS. 5A and 5B , in one embodiment of the present invention, a fastener  40   b  may be used which has a domed head  32   b  with a fastener engagement surface  10   a . The fastener  40   b  may be used for roofing material fastening and includes a modified drill type point  42   b  with a threaded region  44   b  proximate the modified drill type point  42   b.    
         [0049]     As shown in  FIGS. 6A and 6B , in one embodiment of the present invention, a fastener  40   c  may be used which has a head  32   c  with a fastener engagement surface  10   a . The fastener  40   c  may be used for plastic lumber fastening and includes a point  42   c  with a first threaded region  44   c  proximate the point  42   c  and a second threaded region  45  proximate the head  32   c.    
         [0050]     As shown in  FIGS. 7A and 7B , in one embodiment of the present invention, a fastener  40   d  may be used which has a raised head  32   d  with a fastener engagement surface  10   a . the fastener  40   d  may be used for fastening gutters to building structures and includes a point  42   d  with a threaded region  44   d  proximate the point  42   d  and an extended shaft region  46  intermediate the head  32   d  and the threaded portion  44   d.    
         [0051]     As shown in  FIGS. 8A and 8B , in one embodiment of the present invention, a fastener  40   e  may employ a head  32   e  with a fastener engagement surface  10   a . The fastener  40   e  may be used for engineered wood fastening and includes a point  42   e  with a threaded region  44   e  proximate the point  42   e  and includes spur elements  48  used to aid in fastening engineered wood.  
         [0052]     As shown in  FIGS. 9A and 9B , in one embodiment of the present invention, a fastener  40   f  may be used which has a slightly radiused head  32  with a fastener engagement surface  10   a . The fastener  40   e  may be used for fastening ledgers to building structures and includes a point  42   f  with a threaded region  44   f  proximate the point  42   f.    
         [0053]     As shown in  FIGS. 14A and 14B , in one embodiment of the present invention, a wood insulation screw  40   g  may be used which has a raised head  32   g  with a fastener engagement surface  10   a . The fastener  40   g  includes a gimlet point  42   g  with a threaded region  44   g  proximate the point  42   g  and an extended shaft region  46  intermediate the head  32   g  and the threaded portion  44   g . the lengths may range from 6.0 to 14.0 inches. The thread region  44   g  preferably extends 2.0 inches and the vertex point ranges from 25° to 30°.  
         [0054]     As shown in  FIG. 11 , in one embodiment of the invention, the fastener engagement surface  10   b  has an upper portion  26   a  and a lower portion  28   a . The rear wall  16   a  and/or side walls  18   a ,  20   a  of the radial slot  12   a  have portions which are angled relative to an axis “x” that extends through the central axis  14  of the engagement surface  10   b . The angle of portions of the rear wall  16   a  and/or side walls  18   a ,  20   a  may be in a range between about 0° to about 2°. Preferably the angle is about 0° to about 1°. For example, portions of the rear wall  16   a  and/or side walls  18   a ,  20   a  are angled such that a portion of the rear wall proximate the lower portion  28   a  is positioned closer to the axis “x” than a portion of the rear wall  16   a  proximate the upper portion  26   a . The angle of the rear wall  16   a  and/or side walls  18   a ,  20   a  thus forms a bevel  30   a . The bevel  30  formed by the angle of the rear wall  16   a  and/or side walls  18   a ,  20   a , among other things, advantageously facilitates the insertion, engagement, and/or retention of the tool into the engagement surface  10   b . It should be noted that the transition portion  22   a  between the radial slots  12   a  may also have an angled portion similar to the angled portion of the rear wall  16   a  and/or side walls  18   a ,  20   a.    
         [0055]     In one embodiment of the invention, as shown in  FIGS. 10A-10C , a fastener engagement tool  60  includes a drive head  62  having splines  64 . The drive head  62  may be rounded wherein head  62  is radiused convexly such that the head  62  has a substantially spherical configuration. The splines  64  are, in one embodiment of the invention, configured such that they extend outwardly from the head  62  and have an upper surface  65  which follows the radiused countour of the head  62 . The splines have sides  66  which are configured to engage with a fastener tool engagement surface  10   a ,  10   b  such that lateral rotational force can be exerted on the engagement surface  10   a ,  10   b.    
         [0056]     The drive head  62 , in one embodiment of the invention, is fixed to a shaft  61  of the fastener engagement tool by a neck region  68 . The shaft  61  may have flattened areas  70  at one end. The flatted area  70 , among other things, prevents the tool from slipping in, for example, a power tool (not shown) and/or allow the fastener engagement tool  60  to be attached to a hex driver (not shown).  
         [0057]     In one embodiment of the invention, the fastener engagement tool  60  has a center axis  72  which extends longitudinally along the shaft  61  and head  62 , as shown in  FIG. 10C . When the fastener engagement tool  60  is engaged with the fastener engagement surface  10   a , the fastener center axis  14  and the fastener engagement tool center axis  72  are in substantial angular alignment. However, the tool drive head  62 , because of its substantially spherical configuration, allows for the fastener center axis  14  and the fastener engagement tool center axis  72  to be angled relative to one another and still be firmly engaged with the engagement surface  10 . This flexible engagement geometry, for example, allows a longer fastener to be installed even when such a fastener has a slight bend. The flexible engagement also allows the fastener to be installed with a force that is sufficient to keep the head  61  and the engagement surface  10  mechanically engaged. This eliminates the need to apply additional force to a tool/fastener connection as required in conventional tool/fastener connections.  
         [0058]     In one embodiment of the invention, the tool drive head  62  is fixed to the shaft by a neck region  68  which is radiused, as shown in  FIG. 10C . The radiused neck allows the fastener center axis  14  and the fastener engagement tool center axis  72  to be angularly misaligned relative to one another such that the shaft  61  does not contact portions of the fastener head  32 .  
         [0059]     As shown in  FIG. 12A , one embodiment of the present invention includes a fastener engagement surface forming punch  100 . The punch  100  includes a body  102 , which may be configured to be received by a punch holding tool (not shown). A working surface  104  is present at one end of the body  102  and includes a protrusion  106 . The protrusion  106 , as shown in  FIG. 12 , may include a substantially conical portion  107 , flutes  108 , and a profiled shoulder  110 . The substantially conical portion  107  may be configured to facilitate the displacement of material as the punch  100  is brought into engagement with a surface. Advantageously, the conical portion  107  includes an angle “e” which is, for example, approximately 110° to approximately 160°. Preferably the angle “e” is approximately 140°.  
         [0060]     As shown in  FIG. 13 , in one embodiment of the present invention, the flutes  108  are, for example, arranged about a center axis “u” of the protrusion  106 . The flutes  108  have a configuration such that when engaged with a surface of a fastener, a fastener engagement surface  10 ,  10   a ,  10   b  is formed. For example, the flutes  108  may be arranged about the center axis “u” of the protrusion  106  such that when the center axis “u” is aligned with the center axis “x” of the fastener and the punch  100  is engaged with the fastener, the radial slots  12 ,  12   a  are formed.  
         [0061]     As shown in  FIG. 12B , in one embodiment of the present invention, the protrusion  106  includes the profiled shoulder  110  which is configured to form the beveled structure  30 ,  30   a  in the fastener engagement surface  10 ,  10   a ,  10   b , when the punch  100  is engaged with the fastener. The profiled shoulder  110  includes a lower interface  112  which is proximate the punch body  102 , and an upper interface  111  which is distal to the punch body  102 . The profiled shoulder  110  may be present on the protrusion  106  such that when the center axis “u” is aligned with the center axis “x” of the fastener and the punch  100  is engaged with the fastener, angled portions are formed in at least one of the rear wall  16   a , first side wall  18   a , second side wall  20   a , or transition portion  22   a  in a range between approximately 0° to approximately 2°. Preferably the angle is formed in the range of approximately 0° to approximately 1°.  
         [0062]     While the embodiments of the foregoing invention have been set forth for the purpose of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications adaptations and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.