Abstract:
A power tool for installing metal piercing fasteners being characterized by a body bent at one end to form a crown portion and having at least one side guide rail and at least one integral tine under the crown portion, the integral tine being deformed about its longitudinal axis to cause at least one portion of the tine to protrude outwardly from the body of the fastener comprises a fastener guide body including at least one guide channel adapted to accommodate the side guide rail of the metal piercing fastener. The guide channel defines a linear drive path for the metal piercing fastener. The power tool also comprises a fastener driver body including at least one outwardly protruding side spline adapted to conform approximately to the outer contours of the side guide rail of the metal piercing fastener and to slide within the trajectory channel, and a fastener driver tip for forcibly impacting the crown portion of the metal piercing fastener. The fastener driver tip is coupled to one end of the fastener driver body and adapted to follow approximately the outer configuration of the fastener driver.

Description:
RELATED APPLICATIONS  
       [0001]    The present application is related to co-pending U.S. patent application, entitled “FASTENER HAVING GUIDE RAILS” having the same inventors and assignee, attorney&#39;s docket No. 6878-111XX/10214004, the disclosure of which is incorporated in its entirety herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to power tools and more particularly to a power tool for use with metal piercing fasteners having an elongated flat body with one end bent to form a crown and a guide rail along at least one side edge thereof.  
         BACKGROUND OF THE INVENTION  
         [0003]    Securing work pieces together, such as, for example, a top laminate non metal work piece to a bottom light-gauge metal substrate ( 18  gauge and thinner) or alternatively, a light gauge metal work piece to light-gauge metal substrate has generally been accomplished by threaded fasteners. The helical design of the thread has been generally successful in pulling the top laminate materials together tightly with the light-gauge metal substrate. Additionally, the helical thread design has provided sufficient withdrawal resistance to achieve performance values acceptable to the construction industry. However, installation of helical threaded fasteners with traditional rotary power tools has proven time-consuming to the installer. The industries using these light-gauge metals would be better served by a fastener power tool having the speed of a pneumatic nailing system and being adapted for use with metal piercing fasteners having the gripping and clamping capabilities of helical threaded fasteners.  
           [0004]    Pneumatic nailing and power tools are well known in the prior art. Typical examples of such known pneumatic nailing power tools are disclosed in U.S. Pat. Nos. 4,384,623; 5,135,152; 6,155,472; 6,318,618; 6,431,428; and 5,074,453. These structures illustrate various types of power tools for driving nails, metal staples and similar such articles. Typically, these devices include a compressed gas source which drives a piston which in turn, moves a driver into engagement with the fastener device positioned within the drive channel of the tool to cause the fastener to enter the workpiece which is typically wood.  
           [0005]    The most pertinent of the patents above referred to is U.S. Pat. No. 5,074,453 which discloses a pneumatic fastener driving tool for driving a fastener which is formed from an elongated cylindrical rod having a straight leg, a curved head and a bent end portion to drive a hook-shaped fastener into a workpiece. The driving end portion of the tool disclosed in the 5,074,453 patent is designed to provide guide surfaces which engage the leg and the bent end portion of the fastener during the driving operation to prevent the fastener from bending or entering the workpiece at an angle. Applicant is aware of fasteners having elongated flat bodies with the end portion thereof bent over to form a head or crown to thus form sheet metal roofing nails as disclosed in U.S. Pat. Nos. 2,740,505 (Flora); 2,751,052 (Flora); and 3,983,779 (Dimas). These sheet metal roofing nails are designed to be installed manually by hammering them through a layer of insulation and into a metal roofing material. Applicants are unaware of any power tool adapted to install a fastener formed from an elongated flat body, with the end bent to form a crown, into a workpiece including a light gauge metal substrate.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention is generally directed to a power tool for installing metal piercing fasteners comprising a fastener guide body including at least one guide channel adapted to accommodate the outer contours of an elongated flat metal piercing fastener, the guide channel defining a linear drive path for the metal piercing fastener which fastener has a guide rail along one side edge thereof, and a fastener driver body adapted to slide within the guide channel behind the metal piercing fastener for the purpose of forcibly impacting the metal piercing fastener. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The invention is generally shown by way of example in the accompanying drawings in which:  
         [0008]    [0008]FIG. 1 is a side perspective view of a power tool for installing metal piercing fasteners into a plurality of laminar workpieces including a metal substrate to join the workpieces together in accordance with one embodiment of the present invention;  
         [0009]    [0009]FIG. 2 is a partial perspective view of the power tool of FIG. 1;  
         [0010]    [0010]FIG. 3 is a side view of a fastener load mechanism of the power tool of FIG. 1;  
         [0011]    [0011]FIG. 4 is a front view of a fastener guide mechanism of the power tool of FIG. 1;  
         [0012]    [0012]FIG. 5 is a back view of the fastener guide mechanism of FIG. 4;  
         [0013]    [0013]FIG. 6 is a top view of the fastener guide mechanism of FIG. 4;  
         [0014]    [0014]FIG. 7 is a cross-sectional view of a fastener guide body of the fastener guide mechanism of FIG. 4 in accordance with one embodiment of the present invention;  
         [0015]    [0015]FIG. 8 is a partial bottom perspective view of the fastener guide mechanism of FIG. 4 in accordance with one embodiment of the present invention;  
         [0016]    [0016]FIG. 9 is a side perspective view of one component of a fastener drive mechanism of the power tool of FIG. 1;  
         [0017]    [0017]FIG. 10 is a side perspective view of another fastener drive mechanism component of the power tool of FIG. 1;  
         [0018]    [0018]FIG. 11 is a side perspective view of yet another fastener drive mechanism component of the power tool of FIG. 1;  
         [0019]    [0019]FIG. 12 is a front perspective view of a metal piercing fastener being driven by a fastener drive mechanism of the power tool of FIG. 1 in accordance with one embodiment of the present invention; and  
         [0020]    [0020]FIG. 13 is a perspective illustration of a metal piercing fastener for use with the power tool of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Hereinafter, some preferred embodiments of the present invention will be described in detail with reference to the related drawings of FIGS. 1-13. Additional embodiments, features and/or advantages of the invention will become apparent from the ensuing description or may be learned by practicing the invention.  
         [0022]    The drawings are not to scale with like numerals referring to like features throughout both the drawings and the description.  
         [0023]    The following description includes the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention.  
         [0024]    Turning to FIGS. 1-2, a power tool  20  for installing metal piercing fasteners (of the type disclosed in co-pending U.S. patent application, entitled “FASTENER HAVING GUIDE RAILS” having the same inventors and assignee, attorney&#39;s docket No. 6878-111XX, the disclosure of which is incorporated herein by reference) into a plurality of laminar workpieces (at least one of which is a metal substrate) to secure the same together. The fastener as disclosed in the above-identified pending application is shown in FIG. 13 to which reference is hereby made. The fastener  1  as therein illustrated includes an elongated body  2  having a point  4  for penetrating the workpiece and the metal substrate provided at the opposite end of the elongated body  2  is a head  6  which is formed by bending over one end of the body  2 . The head  6  is adapted for engagement by a power tool constructed in accordance with the present invention to drive the fastener  1  through the workpiece and the metal substrate. A securing member  8  is carried by the body  2  for securing the workpiece and the metallic substrate together after insertion of the fastener. The securing member  8  as illustrated in FIG. 13 is a tine which is disposed within an opening  9  formed in the body  2 . The tine extends from the lower portion of the opening and protrudes upwardly into it. As is shown in FIG. 13, the tine is deformed about its longitudinal axis as it passes through the aperture formed by the point  4  it flattens into the opening  9  and does not distort the aperture dimensions. The securing member then by friction from the edges locking within the formed aperture holds the workpiece and the metal substrate together. The body  2  of the fastener  1  has a width dimension W 1  and the head  6  has a width dimension W 2 . The width dimension W 1  of the body is greater than the width dimension W 2  of the head. As a result, a pair of guide rails  5  and  7  are provided along the two side edges  3  and  3 ′, respectively, of the body  2 . These guide rails  5  and  7 , as will be discussed in more detail below, cooperate with guide channels provided in the power tool to maintain the fastener  1  substantially perpendicular to the surface of the workpieces at all times during installation of the fastener  1  into the workpieces.  
         [0025]    The power tool  20  comprises a housing  22 , a barrel portion  24  coupled to the housing  22 , and a magazine  26  coupled between barrel portion  24  and the housing  22 . Magazine  26  (FIGS. 1-2) is of a generally hollow cylindrical configuration adapted to receive a supply coil of fasteners  27  (FIG. 3) and includes an integral door  29 , as generally shown in FIG. 1. Housing  22  includes a handle  28  (FIG. 1) and a compressed air mechanism (not shown) adapted to provide the pneumatic force needed to install metal piercing fasteners, such as the metal piercing fastener  33  (FIGS. 1, 2 and  13 ), one at a time into a stack of laminar workpieces.  
         [0026]    Barrel portion  24  comprises a conventional fastener load mechanism  30  (FIGS. 2-3) which includes an indexing feed actuator (not shown) for advancing the fasteners into a ‘ready position’ (see FIG. 3) for firing, a fastener guide mechanism  32  (FIGS.  2 ,  4 - 6 ) operatively coupled to fastener load mechanism  30  (FIG. 2), and a fastener drive mechanism  34  (FIGS. 8-12) operatively coupled between the compressed air mechanism and fastener guide mechanism  32  (FIG. 2). As generally depicted in FIGS. 1-2, barrel portion  24  also comprises a generally hollow cylindrical nozzle  36  which incorporates a portion of fastener guide mechanism  32  and includes at its outer end a generally ring-shaped spring-loaded foot  38  adapted to be pressed down against a generally flat top substrate surface until a compression spring (not shown) in foot  38  is collapsed. When the power tool  20  is ready to be activated to install a fastener, the surface  39  of the foot  38  rests on the top surface of the work piece and is even with the lower surface  41  of the magazine  26 , that is, the surfaces  39  and  41  are on the same plane. The surface  41  of the magazine  26  is positioned on the top surface of a work piece and provides a guide or rest useful to the operator to ensure that the fastener  33  is at a substantially right angle to the work piece before the power tool is activated. Before the foot  38  engages the surface of the work piece, it extends slightly below the surface  1  of the magazine  26 . When the foot  38  is in this position, the power tool cannot be activated even if the trigger is pulled. This ensures that the tool is in a position prior to activation that will cause the fastener to enter the work piece and substrate at a substantially ninety degree (90°) angle with respect to the work piece surface. As is illustrated in the perspective view of FIG. 1, the surfaces  39  and  41  are on the same plane allowing the fastener  33  to be ejected from the nozzle  36 .  
         [0027]    Fastener drive mechanism  34  (FIGS. 8-12) preferably comprises a generally hollow cylindrical driver body  40  (FIG. 9) which includes a generally arcuate driver head portion  43  (FIG. 9) and generally elongated outwardly protruding (right and left) side and bottom driver splines  42  and  44 , and a downwardly protruding U shaped extension  46  (FIG. 9), adapted to conform generally to the outer contours of the drive channel through which the fastener is driven. Driver body  40  (FIG. 9) may be made of metal or other similar material, provided there is no departure from the intended purpose of the present invention. Fastener drive mechanism  34  also comprises a fastener driver tip  50  (FIG. 11) adapted for coupling to one end of driver body  40 , and a piston attachment member  60  (FIG. 10) adapted, respectively, for coupling to an opposite end of driver body  40 .  
         [0028]    Fastener driver tip  50  is of a generally stepped configuration including raised front and recessed back portions  51 - 53 , respectively, with recessed back portion  53  being adapted to be inserted for attachment into one end of hollow driver body  40 . Attachment may be accomplished, for example, via a pair of roll pin attachment apertures  52  formed in back portion  53 , a pair of roll pins (not shown), and a corresponding pair of roll pin attachment apertures  48   a  on protrusion  46  of driver body  40 . Other means of attachment may be used provided such other attachment means do not deviate from the intended scope and spirit of the present invention.  
         [0029]    Raised front portion  51  follows generally the outer configuration of driver body  40  by including (right and left) side and bottom driver splines, such as splines  56  (FIG. 11),  57  (FIG. 12), and  58  (FIGS. 11-12), respectively, except that the driver splines ( 56 ,  57 ,  58 ) have inwardly tapered front edges, as generally illustrated in FIGS. 11-12, to ensure non-marring of the top laminar work piece during use of pneumatic gun  20 , in accordance with the general principles of the present invention. Front portion  51  includes a generally arcuate solid driver face  59  (FIG. 11) which generally follows the outer contours of crown  35 , FIGS. 6 and 8 (FIG. 13) of metal piercing fastener  33  and is intended to forcibly impact crown  35  when pneumatic power tool  20  is fired, as generally depicted in FIGS. 8 and 12. Driver tip  50  is preferably fabricated from impact-resistant materials such as, for example, nickel titanium metal alloys or other similar impact resistant materials.  
         [0030]    As generally depicted in FIG. 10, piston attachment member  60  includes a threaded front portion  62  adapted for attachment to a drive piston (not shown) operatively coupled to the air compression mechanism (of pneumatic power tool  20 ), a raised generally cylindrical portion  64 , and a recessed back portion  66 . Back portion  66  is preferably adapted to be inserted for attachment into the other end of hollow driver body  40  from where the driver tip  50  is disposed. Attachment may be accomplished, for example, via a pair of roll pin attachment apertures  68  on a bottom extension  70  (of recessed back portion  66 ), a pair of roll pins (not shown), and one of corresponding pairs of roll pin attachment apertures  48   b  on driver protrusion  46  (of driver body  40 ). Other means of attachment may be used provided such other attachment means do not deviate from the intended scope and spirit of the present invention.  
         [0031]    Fastener guide mechanism  32  (FIG. 2) preferably comprises a generally hollow cylindrical guide body  72  (FIGS. 4-5) which is coupled to housing  22  via a mounting flange  74  (FIGS.  2 ,  4 - 6 ) having a generally circular cross-section. As generally depicted in FIG. 7, guide body  72  has an internal cross-section adapted generally to accommodate the outer contours of a fastener being driven therein. For example, the outer contours of fastener  1  (FIG. 13) may be generally determined by fastener crown portion  6  which is bent relative to the body of fastener  1 , right and left side guide (edge) rails  5  and  7  on the body  2  of fastener  1 , and an integral tine  8  which is twisted to cause at least one portion of tine  8  to protrude outwardly from the body of fastener  1 , as generally illustrated in FIG. 13. Specifically, guide body  72  is preferably provided internally with generally elongated right and left side guide channels  90 - 92  (FIGS. 6-7) which define a linear drive path for a fired fastener such as fastener  1  of FIGS. 17. Guide channels  90 - 92  are adapted to slidingly accommodate the right and left side guide rails  5  and  7  of fastener  1  (FIG. 17), as well as right and left side driver splines  42 - 44  of driver body  40  (FIG. 9), respectively, during operation of pneumatic power tool  20 , in accordance with a preferred embodiment of the present invention.  
         [0032]    Guide body  72  is also provided internally with a generally arcuate fastener crown clearance area  94  (FIGS. 6-7) which is adapted to clear the outer contours of a fastener crown portion, such as, for example, crown portion  80  of fastener  84  (FIG. 3), driver head portion  43  (FIG. 9), and driver face  59  of driver tip  50  (FIG. 11) during operation, in accordance with another preferred embodiment of the present invention.  
         [0033]    Guide body  72  is further provided internally with a generally rectangular tine relief channel  96  (FIGS. 6-8) disposed generally opposite crown clearance area  94  and adapted to clear the outwardly protruding tine portion of a driven fastener such as, for example, outwardly projecting tine portion  8  of fastener  1  of FIG. 13, the outer contours of driver protrusion  46  of driver body  40  (FIG. 9), during operation, in accordance with yet another preferred embodiment of the present invention.  
         [0034]    A person skilled in the art would recognize that all of the above-described components are easily replaceable if the need arises and that other components and/or configurations may be utilized in the above-described embodiments, provided such other components and/or configurations do not depart from the intended purpose and scope of the present invention.  
         [0035]    While the present invention has been described in detail with regard to one or more exemplary embodiments, it should also be appreciated that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. In this regard it is important to note that practicing the invention is not limited to the applications described hereinabove. Many other applications and/or alterations will be apparent to those skilled in the art.  
         [0036]    It should be appreciated by a person skilled in the art that features illustrated or described as part of one embodiment may also be used in other embodiments. It is, therefore, intended that the present invention cover all such modifications, embodiments and variations as long as they come within the scope of the appended claims and their equivalents.