Abstract:
A nail gun and spacer assembly for ejecting nails into a substrate which contains two or more layers of roofing materials one of which is a compressible fibrous layer. The nails penetrate the substrate but are prevented by the spacer from permanently compressing the compressible fibrous layer which springs back to is original thickness after completion of the nailing process. The spacer, attached to the base of the nail gun, is of semi-oval configuration having a pressure sensitive layer and a solid layer, is provided with an oval cavity in its center portion through which the nails are ejected into the substrate.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a nail gun in general, and more particularly, to a nail gun attachment in the form of a spacer which prevents compressing and crushing a building material when installed over a structure using nails.  
           [0003]    2. Reported Developments  
           [0004]    Nail guns are well-known in the prior art and their use in building construction greatly improves the speed, safety and accuracy of attaching together construction elements by the use of nails. Examples of nail guns can be found in U.S. Pat. Nos. 5,261,588, 5,180,091 and 4,570,840.  
           [0005]    Briefly described, a nail gun comprises:  
           [0006]    a driving cylinder for ejecting nails upon actuation thereof;  
           [0007]    a handle of a generally rectangular, closed loop configuration coupled to a peripheral side wall; and  
           [0008]    a trigger mounted on an intersection between the driving cylinder and the handle for selectively actuating the driving cylinder.  
           [0009]    Nail guns provide for easy, convenient and fast delivery of nails into building materials for fastening such materials to each other. Certain building materials, however, require attachment to nail guns for affixing layers of sheet materials together without damaging the materials intended for special uses, as exemplified by the following.  
           [0010]    In the building industry when two sheets of materials are being fastened together it is necessary to space the two sheets of materials at a pre-determined distance apart from each other, such as when installing dry walls, placing foam insulation between vinyl or aluminum siding panels and outer wall sheathing, or installing a roof ridge vent using a synthetic fiber matting covered by asphalt cap shingles. The nails used, without a provision for spacing the sheet materials apart from each other, tend to crush the soft materials or cause indentations around the nails in the composite materials. Such indentation vary from minor indentation resulting in less than aesthetically pleasing appearance to the reduction in insulating efficacy of the composite material. An example of the latter occurrence is the installation of a mat made of randomly aligned synthetic fibers joined by phenolic or latex bonding which is heat cured to provide the mat with varying mesh. This material is sold by GAF Materials Corporation, and is available under the name COBRA® Ridge Vent and is described in U.S. Pat. No. 5,167,579. When the COBRA® mat is nailed to the ridge vent, then covered by shingles using manual installation techniques, or nail guns without having a means to keep the two layers spaced from each other, the mat is compressed by being crushed by the nails resulting in loss of the R value of the mat.  
           [0011]    U.S. Pat. No. 5,511,918 discloses a nail used manually or with a pneumatic gun for securing two materials together spaced by an interposed resilient material. The nail has a head at one end, a shaft extending from the head and terminating in a sharp point. The nail is equipped with a sleeve having a cylindrical center portion and a pair of frusto-concical tapered portion. The sleeve surrounds the shaft and has a length in excess of the resilient material and less than the length of the shaft.  
           [0012]    The method of using the nail equipped with the sleeve to affix two sheets together interposed by a resilient layer includes the steps of:  
           [0013]    laying the first sheet on a supportive substrate;  
           [0014]    laying the resilient layer on top of the first sheet;  
           [0015]    laying the second sheet on top of the resilient material;  
           [0016]    driving the point of the nail through the second sheet, the resilient layer and into the first sheet.  
           [0017]    The cutting edge of the sleeve cuts the second sheet and the resilient layer. The cutting edge of the sleeve stops at the first sheet without penetrating the first sheet for the reason that the length of the sleeve is no more than the combined thickness of the first sheet and the resilient layer. As a result of the limiting length of the sleeve the resilient layer is not crushed or compressed by the nail. However, it will be noted by those skilled in the art that while this invention greatly reduces the compression of the resilient layer in the vertical direction, the sleeve exerts a compression or crushing force in the lateral direction. The extent of such compressive or crushing forces is proportional to the thickness of the sleeve. An object of the present invention is to reduce such compressive or crushing forces both in the vertical and the lateral directions.  
           [0018]    U.S. Pat. No. 5,564,614 is directed to a nailing depth adjusting mechanism for a pneumatic nail gun comprising: a firing control strip fastened to the gun and driven to release the firing pin thereof; and a wheel for adjusting the nailing depth of the gun.  
           [0019]    The present invention utilizes a concept which is different from those of the prior art in providing an attachment to a nail gun by which compression and/or crushing a fibrous material interposed between two sheets is prevented.  
         SUMMARY OF THE INVENTION  
         [0020]    In accordance with the present invention a spacer is proved which is attached to a nail gun forming an assembly by which nails expelled therefrom into a substrate penetrate the substrate but leave a space or gap between the nail head and the top surface of the substrate. The use of the nail gun and spacer assembly typically involves substrates that contain more than one layer at least one of which is compressible. During the nailing process the thickness of the compressible layer is reduced but the space or gap between the nail head and the top layer of the substrate allows the compressible layer to spring back allowing the top layer of the substrate to contact the nail head and thereby providing a continuous top surface without indentations around the nails.  
           [0021]    The spacer comprises a layer of a pressure sensitive material and a layer of metal or polymeric material of rigid or semi-rigid consistency. The pressure sensitive layer is covered with a release paper which allows storing of the spacer prior to attachment thereof to a nail gun. The configuration of the spacer is such that it allows attachment thereof to most of the commercially used nail guns. While the spacer is described herein is preferably attached to the base of the nail gun by the pressure sensitive layer, other means of attachment may also be used within the inventive concept of the invention, such as screws and clips.  
           [0022]    The preferred embodiment of the spacer being a composite of two layers having a semi-oval configuration comprising:  
           [0023]    a distal end, a proximal end and a center portion;  
           [0024]    a horizontal top portion at the distal end;  
           [0025]    a first vertical side portion extending from the horizontal top portion towards the proximal end;  
           [0026]    a second side portion extending from the first vertical side portion towards the proximal end at a slight angle from the vertical portion towards the center;  
           [0027]    a third side portion at the proximal end extending from the second side portion and enclosing an obtuse angle forming the tip of the spacer; and  
           [0028]    an oval cavity having a longitudinal axis and a transverse axis in the center portion of the spacer, the longitudinal axis of which points in the vertical direction, and the transverse axis of which points in the horizontal direction. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    [0029]FIG. 1 is a perspective view of the spacer of the present invention in which the top layer is partially cut away;  
         [0030]    [0030]FIG. 2 is a side elevational view of a ridge vent system showing layers of roofing materials attached to a substrate with nails which were propelled by a nail gun, said nail gun having been equipped with the spacer;  
         [0031]    [0031]FIG. 3 is a top plan view of the spacer showing top and side portions thereof and the oval cavity therein;  
         [0032]    [0032]FIG. 4 is a top plan view of the spacer showing the longitudinal diameter, the transverse diameter and the radius of the area of the oval cavity thereof;  
         [0033]    [0033]FIG. 5 is a top plan view of the spacer showing the length of the horizontal top portion; the length of the second side portion, and the space between the horizontal top portion and the distal end portion of the oval cavity thereof;  
         [0034]    [0034]FIG. 6 is a partial top plan view of the spacer showing the length of the horizontal top portion; the length of the first vertical side portion, and total length from the horizontal top portion to the tip of the third side portion, and the distance between the points where the second and third side portions meet on each side thereof;  
         [0035]    [0035]FIG. 7 is a top plan view of the spacer showing the angle enclosed by the first side portion and the second side portion on each side of the spacer, the angle enclosed the second side portion and the third side portion, and the angle enclosed by the two third side portions;  
         [0036]    [0036]FIG. 8 is a partial side and top plan view of the spacer showing the thickness of the top layer and the bottom layer; and  
         [0037]    [0037]FIG. 9 illustrates the attachment of the spacer to the base of a nail gun, the nail gun being shown in phantom. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]    [0038]FIG. 1 is a perspective view of the spacer, generally designated by the numeral  10 , comprising a top layer  12  of pressure sensitive adhesive, and a bottom layer  14  of a hard or semi-flexible polymeric material. The top layer in FIG. 1 is partially cut away to illustrate the composition of the spacer. As used herein, the word “spacer” denotes a three-dimensional object which separates two points or surfaces from each other and maintains them apart for a given time period. The bottom layer of the spacer is made of metal, such as steel, copper and aluminum or a polymeric material, such as polyethylene, polypropylene, polystyrene, acrylic polymers and methacrylic polymers. The bottom layer preferably is stiffer than the top layer and can be semi-rigid or rigid. Preferably, the bottom layer is made of thermoplastic materials of sufficient thickness which together with the pressure sensitive layer provides the desired thickness in between a nail head and a cap shingle which is described later. The pressure sensitive adhesive used as the top layer of the spacer can be any pressure sensitive adhesive known in the prior art that provides the required adhesion or “tackiness” so that it adheres to the bottom layer of the spacer as well as to the base of the nail gun with which it is used. A release sheet covers the top of the pressure sensitive layer (not shown) prior to attachment of the spacer to the base of the nail gun. In a preferred embodiment, the spacer comprises a pressure sensitive layer having a thickness of 0.008″-0.06″ and a rigid or semi-rigid layer having a thickness from 0.125″-0.250″.  
         [0039]    [0039]FIG. 2 is a side sectional view of layers of a built-up roof showing a nail which has been inserted by a nail gun into the layers. In some detail, FIG. 2 shows venting system  16  used to vent hot air from the attic through an open slot  18  in the ridge of a roof. The slot is formed by cutting a sheeting material, such as an upper sheeting panel  20 , about ¾″ short of the ridge crest formed by the rafters  22 . Roof shingles are laid in overlapping rows up to the open slot  18 . A unitary mat  26  of randomly aligned synthetic fabrics is laid on the top of the upper row sheeting panel  20 . The mat is about ¾″ thick. It runs the length of the slot extending evenly on each side. Cap shingles  28  are then laid over the mat and are secured by driving a nail through the cap shingle  28 , mat  26 , and the roof shingles  24  into the underlying sheathing  20  and rafters  22 . Nail  30  is driven into the layers from a pneumatic nail gun the base of which carries the spacer of the present invention. The dimensions of the spacer used in the venting system are described in connection with the following FIGS.  3 - 6  in which the dimensions are measured in inches.  
         [0040]    FIGS.  3 - 7  show top plan views of the spacer. Generally characterized, the circumference of the spacer is semi-oval, i.e., an oval shaped body having a longitudinal axis and a transverse axis is cut into two equal halves along the transverse axis. The top plan views in FIGS.  3 - 7  show the bottom half of the oval shaped body. The center portion of th e spacer is provided with an oval cavity the longitudinal axis of which is vertically oriented and the transverse axis of which is horizontally oriented.  
         [0041]    Referring to FIG. 3, spacer  10  comprises:  
         [0042]    a horizontal top portion  36  at the distal end;  
         [0043]    a first vertical side portion  38  running from the top portion towards the proximal end;  
         [0044]    a second side portion  40  running from the vertical side portion towards the proximal end at a slight angle from the vertical;  
         [0045]    a third side portion  42  at the proximal end extending from the second side portion and enclosing an obtuse triangle forming the tip of the spacer; and  
         [0046]    a centrally positioned oval cavity  46  in the spacer, the longitudinal axis of which is pointed in a vertical direction.  
         [0047]    The cavity is spaced from the top, side and bottom portions of the periphery of the spacer.  
         [0048]    The dimensions of the spacer are shown in FIGS.  4 - 8 , wherein the numerals denote inches. While the numeral denote actual dimensions, the scale of the drawing is a close approximation of the numerals. FIGS.  5 - 7  are top plan views while FIG. 8 is a partial side and top plan view of the spacer.  
         [0049]    [0049]FIG. 4 shows the following: the longitudinal diameter of the oval cavity is 0.9500″; the transverse diameter of the oval cavity is 0.6250″; and the radius of the arc at the distal and proximal ends of the cavity is 0.3125″.  
         [0050]    [0050]FIG. 5 shows the following: half of the length of horizontal top portion  36  of the spacer is 0.7500″ and, therefore, the full length of the horizontal top portion is 1.5000″ which is also shown in FIG. 6; the distal arc of the cavity is spaced from the horizontal top portion at 0.1500″; second side portion  40  has a length of 0.7906″; the third side portion has a length of 0.5590″.  
         [0051]    [0051]FIG. 6 shows the following: the length of the horizontal top portion is 1.5000″; the length of the first vertical side portion  38  is 0.2500″; the total vertical length of the spacer from the horizontal top portion to the tip of the third side portion is 1.5000″; and the distance shown by the dotted line between the points where the second and third side portions meet on each side of the spacer is 1.000″.  
         [0052]    [0052]FIG. 7 shows the following: the angle enclosed by the first side portion  38  and the second side portion  40  is 162° on each side of the spacer; the angle enclosed by the second side portion  40  and the third side portion  42  is 135° on each side of the spacer; and the angle enclosed by the two third side portions  44  is 127°.  
         [0053]    [0053]FIG. 8 shows that top layer  12  of the spacer, which is the pressure sensitive adhesive layer, has a thickness of 0.0600″; and the bottom layer  14 , which is the metal or polymeric layer, has a thickness of 0.1250″.  
         [0054]    [0054]FIG. 9 shows the method of installation of the spacer  10  on the pneumatic nail gun  48  having a nail hole exit  50 , wherein the nail gun, the nail hole exit as well as the hands of the installer are shown in phantom. The method includes the steps of:  
         [0055]    disconnecting the air supply line from the nail gun;  
         [0056]    removing the release paper or film from the spacer to expose the pressure sensitive layer:  
         [0057]    aligning the spacer so that the nail hole exit is inside the oval cavity of the spacer;  
         [0058]    pressing the spacer against the base of the nail hole exit for adhesive bonding thereof;  
         [0059]    inserting the coil of 1¾″ roofing nails into the nail gun; and  
         [0060]    reconnecting the air supply line to the nail gun.  
                                             PARTS LIST                                    Spacer, generally designated   10           Top or adhesive layer of spacer   12           Bottom layer of spacer   14           Venting system   16           Open slot in venting system   18           Upper row sheeting panel   20           Rafters   22           Roof shingles   24           Unitary fibrous mat   26           Cap shingles   28           Nail   30           Horizontal top portion of spacer   36           First vertical side portion of spacer   38           Second side portion of spacer   40           Third side portion of spacer   42           Tip at the proximal end of spacer   44           Oval cavity in spacer   46           Nail gun   48           Nail hole exit   50                      
 
         [0061]    Various modifications of the present invention disclosed will become apparent to those skilled in the art. This invention is intended to include such modifications to be limited only by the scope of the claims.