Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application claims priority to provisional patent application Ser. No. 60/515,990, titled “Sliding Rail Containment System for Flexible Collated Screws,” filed on Oct. 31, 2003. 

   TECHNICAL FIELD 
   The present invention relates generally to portable screw driving equipment and is particularly directed to a motorized tool of the type which receives a flexible strip of collated screws, and automatically drives individual screws from the collated strip into an object. The invention is specifically disclosed as a portable screw driving tool that receives a flexible collated strip of screws from a “top” area of the tool, and provides a means of containment so as to prevent the flexible collated strip from becoming substantially misaligned, which could lead to the strip bunching up or becoming tangled. The collated strip is directed into a pathway (or slot) of a sliding rail sub-assembly, and the strip moves through the pathway/slot until the strip reaches the screw-driving front position of the tool. The pathway/slot contains the flexible strip as the strip moves therethrough, regardless of the orientation of the screw driving tool with respect to the ground, as a source of gravity. 
   The screw driving tool has the sliding rail sub-assembly mounted along an upper or top area of the tool (when the tool is positioned in a horizontal direction). When the tool is actuated to drive a screw into an object, the sliding rail moves longitudinally along the top of the tool, along with the tool&#39;s front-end screw-driving mechanism. Thus the flexible collated strip is always in a relatively fixed orientation as compared to the front end portion of the tool, as well as the sliding rail portion. This assists in preventing the flexible strip from becoming misaligned, by bunching or becoming tangled, and tends to eliminate screw misfeeds. 
   BACKGROUND OF THE INVENTION 
   Portable hand-held screw driving tools have been available from Senco Products, Inc. for several years. Some of the previous tools sold by Senco were used with screw lengths in the range of one inch to two inches. Many of these tools have been “top feed” tools, in which a flexible collated strip of screws was fed into the top portion of the tool toward the front or nose of the tool, where the individual screws are taken from the collated plastic strip and driven into a solid object. 
   The flexible collated screw strips can be difficult to manage, and at times it is difficult to prevent the screws from bunching or tangling during a driving sequence. For example, this tangling/bunching phenomena can occur when the collated screws have been fed into a slide body mechanism; once the driving mechanism has been actuated, the screws could have a tendency to cross over one another, perhaps creating a jam or a misfeed. This may occur whether the tool is being driven in a horizontal or a vertical plane (or at other angles). 
   In some of the earlier tools sold by Senco, the collated strip of screws may not tend to readily become bunched or tangled during drive sequences of the tool, perhaps because the screws were not very long. For example, two-inch screws have been used in some Senco tools, such as those sold under the Model Numbers DS200, DS200-D2, and DS200-D4. On the other hand, some earlier Senco tools used three-inch screws, such as Senco Model Numbers DS300 and DS300-D2. 
   In some of the earlier Senco top-feed screw driving tools, there was a fixed “top” guide rail that fed the collated strip of screws to the front (drive portion) of the tool. An example of this configuration is the Senco tool Model Number DS200-D4. In some of the other earlier Senco top-feed screw driving tools, there was a movable “top” guide rail that fed the collated strip of screws to the front (drive portion) of the tool. An example of this configuration is the Senco tool Model Number DS300-D2. However, the guide rail on the model DS300-D2 was spaced-apart from the top of the tool main body, and a rigid metal bracket is used to help support the guide rail and to help direct the collated strip of screws to the front end of the tool. 
   It would be an improvement to provide a top-feed portable hand-held screw driving tool that could be used with longer screws that were provided on a collated strip, but at the same time to provide a means for preventing the collated strip from becoming misaligned, by sagging or otherwise bunching or becoming tangled. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an advantage of the present invention to provide a portable hand-held screw driving tool that can feed a collated strip of screws from the top portion of the tool to the nose of the tool in a manner that prevents the flexible collated strip from becoming substantially misaligned, e.g., from substantially bunching, tangling, or sagging. 
   It is another advantage of the present invention to provide a portable hand-held screw driving tool that has a movable guide member mounted along the upper portion of the tool that feeds a flexible collated strip of screws therethrough, then passes the collated strip of screws to a front or nose portion of the tool while keeping the collated strip of screws from becoming substantially misaligned, e.g., from substantially sagging, bunching, or becoming tangled. 
   It is yet another advantage of the present invention to provide a portable hand-held screw driving tool that accepts a flexible collated strip of rather lengthy screws through a slidable guide member that mounts on the upper portion of the tool, in which the upper guide member includes a longitudinal slot or pathway that feeds the flexible collated strip of screws toward a front driving portion of the tool, and that keeps the strip of screws from becoming substantially misaligned while the tool is operated to drive the screw at the nose portion of the tool, in which the movable guide member can slide in a longitudinal motion along with the nose portion of the tool during the driving operation of the tool. 
   It is still another advantage of the present invention to provide a portable hand-held screw driving tool that accepts a flexible collated strip of screws of a longer length, such as in the range of 2–4 inches (or longer) and which are heavier than shorter 1–2 inch screws, in which a slidable guide accepts the collated strip through a slot or pathway on the guide member that is mounted on the upper portion of the tool, and which guides the collated strip toward the front or nose portion of the tool at a driving position, and which directs the flexible collated strip of screws to a slide body sub-assembly that indexes the individual screws toward the driving position, all the while keeping the screws from becoming substantially misaligned, e.g., from substantially bunching, tangling, or sagging. 
   Additional advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. 
   To achieve the foregoing and other advantages, and in accordance with one aspect of the present invention, a movable guide apparatus is provided for use with a portable fastener-driving tool, wherein the fastener-driving tool exhibits: (i) a housing having a first end and a second end, and a wall member therebetween; and (ii) a fastener driving mechanism proximal to the first end of the housing, for receiving a collated strip of fasteners and moving a fastener of the collated strip of fasteners to a driving position; and in which the movable guide comprises: an elongated member having a third end and a fourth end, the elongated member being positioned proximal to the wall member of the tool&#39;s housing, the third end being proximal to the first end of the housing, and the fourth end extending toward the second end of the housing; the elongated member including a longitudinal pathway having an entry area proximal to the fourth end and an exit area proximal to the third end, the collated strip of fasteners being received at the entry area and then directed through the pathway toward the exit area, the collated strip of fasteners being directed from the exit area toward the fastener driving mechanism; and the elongated member being in a movable mechanical communication with the wall member of the housing, and in a fixed mechanical communication with the fastener driving mechanism. 
   In accordance with another aspect of the present invention, a portable fastener-driving tool is provided, which comprises: (a) an elongated housing containing a prime mover device, the housing having a first end and a second end, and a wall member therebetween; (b) a fastener driving mechanism proximal to the first end of the housing; and (c) a movable guide member having a third end and a fourth end, the third end being proximal to the first end of the housing, the guide member including a guiding pathway for a collated strip of fasteners, the guiding pathway having an exit area at the third end; wherein the guide member is in a movable mechanical communication with the housing, and is in a fixed mechanical communication with the fastener driving mechanism. 
   Still other advantages of the present invention will become apparent to those skilled in this art from the following description and drawings wherein there is described and shown a preferred embodiment of this invention in one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description and claims serve to explain the principles of the invention. In the drawings: 
       FIG. 1  is a perspective view from above and from the side-front quarter of a portable hand-held screw driving tool that accepts a flexible collated strip of screws from a top portion of the tool, as constructed according to the principles of the present invention. 
       FIG. 2  is a side elevational view of the screw driving tool of  FIG. 1 . 
       FIG. 3  is a perspective view from above and mainly the front of the screw driving tool of  FIG. 1 , showing further details of the screw driving tool in which the collated strip of screws is not extended all the way to the front driving position of the tool. 
       FIG. 4  is a perspective view from above and the front-side quarter of the screw driving tool of  FIG. 1 , showing the screw driving tool as the collated strip of screws extends all the way to the front “driving” position at the nose of the tool, in which the tool is in its relaxed, non-firing state. 
       FIG. 5  is a perspective view from the side and slightly above the screw driving tool of  FIG. 1 , showing the nose piece in its actuated “firing” position, and also showing the sliding guide rail in its actuated position, in which the actuated position is the “firing” position of the tool. 
       FIG. 6  is a side elevational view of the sliding guide rail that mounts to the upper portion of the tool of  FIG. 1 . 
       FIG. 7  is a perspective view from above and the side-front quarter of the slidable guide rail that mounts to the upper portion of the tool of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings, wherein like numerals indicate the same elements throughout the views. 
   Referring now to the drawings,  FIG. 1  shows a portable screw driving tool, generally designated by the reference numeral  10 , which has a housing portion  20 , a front end portion  30  where the screws are driven into an object, and a handle portion  40 . A slidable screw feed guide rail is generally designated by the reference numeral  50 , and is slidably mounted to an upper area of the housing portion  20 . The portable tool  10  is often used in a vertical orientation to drive screws downward into a floor surface, such as a patio deck. Since the tool  10  is often used to drive vertically downward, it has an adjustable height mechanism, which includes two connecting rods  24  that allow the handle portion  40  to have a variable distance from the housing portion  20 . 
   The handle portion  40  has a pistol-type grip with a trigger  44 , that mechanically actuates an electrical motor (not shown) that is inside the housing portion  20 . The top area of the handle portion  40  includes a gripping surface  42 , while a portion of the bottom surface of the rear extension and the rear portion of the handle itself have gripping surfaces, altogether at  48 . 
   The housing portion  20  includes a front housing outer shell structure  22 , which receives the adjustable length connecting rods  24 . A fixed feed tube  26  is located at the front end of the outer shell structure  22 . The front housing  22  comprises a surrounding wall member essentially throughout its length, and there are several ventilation slots  28  in its lower side wall portions. The feed tube  26  houses some of the movable portions of the tool  10  as discussed below. In the illustrated embodiment, feed tube  26  is fixedly attached to the internal mechanical mechanisms contained within housing portion  20 , such as a motor, a gearbox, and a clutch (not shown). 
   The portable tool  10  includes an electric motor (not visible in  FIG. 1 ) within the housing  22  as a prime mover device to actuate the fastener drive portions of the tool, and electrical power is provided through an electric cord  46 . The prime mover device is generally designed by the reference numeral  68 . Many of the internal “drive components” that include the prime mover device  68  of tool  10  are similar to those disclosed in a commonly-assigned companion patent application titled, “TENSIONING DEVICE APPARATUS FOR A BOTTOM FEED SCREW DRIVING TOOL FOR USE WITH COLLATED SCREWS,” filed on Sep. 29, 2004, Ser. No. 10/953,422, which is assigned to Senco Products, Inc., and which is incorporated herein by reference in its entirety. 
   The front end portion  30  includes a movable nose piece  32 , which is attached to a slide body sub-assembly  34 . Both the nose piece  32  and slide body sub-assembly  34  are movable in a longitudinal direction of the tool  10 , and when the nose piece  32  is pressed against a solid object such that it displaces linearly toward the rear, the screw driving tool  10  will be actuated to physically drive one of the screws into the solid object (also sometimes referred to herein as the “workpiece”). Nose piece  32  has a front surface  36 , which preferably has a rough texture such as sandpaper, so that it will not easily slide while pressed against the surface of the workpiece when the tool is to be utilized. In the illustrated embodiment of  FIG. 1 , the nose piece  32  is detachable from the slide body sub-assembly  34  so that nose piece  32  can be re-positioned for different lengths of screws. The nose piece  32  has a plurality of screw length positioning holes  38  (see  FIG. 3 ), which are used to attach nose piece  32  to the slide body sub-assembly  34  at different relative positions to one another. 
   Much of the mechanical mechanisms described above for the portable screw driving tool  10  have been available in the past from Senco Products, Inc., including such tools as the Senco Model Nos. DS200-D4 and DS300-D2. These earlier tools may not have had the precise same construction as described above in reference to  FIG. 1 , but there are certainly some similarities. 
   At the upper areas of the front housing  22  is a guide “rail” device to direct a strip of collated screws toward the front portion of the tool  10 . This “guide rail” structure is referred to herein as a screw feed guide rail  50 , which includes a left rail half  52  and a right rail half  54 . Further details of this screw feed guide rail  50  are described below, but in general for the present invention, the screw feed guide rail  50  is movable in the longitudinal direction of the tool  10 , such that it can slide along a set of protrusions or tangs  82  and  84  (see  FIGS. 6 and 7 ) at the same time the movable nose piece  32  and the slide body sub-assembly  34  are moved in that longitudinal direction. In this manner, the screw feed guide rail  50  and the slide body sub-assembly  34  are fixedly attached to one another, and this combination is slidably in mechanical communication with the housing portion  20 . The tangs  82  and  84  provide a linear bearing surface against internal portions of the wall member that makes up the housing outer shell structure  22 . 
   It will be understood that the tangs  82  and  84  could instead be included as part of the housing outer shell structure  22 , rather than being included in the screw feed guide rail  50  as described above and illustrated herein, without departing from the principles of the present invention. In this alternative mode of the invention, the screw feed guide rail  50  would then have some type of recessed linear bearing surfaces to receive the tangs that would then protrude from the housing outer shell structure  22 . 
   The main purpose of tool  10  is to drive screws that are provided in the form of a flexible collated strip sub-assembly that is generally designated by the reference numeral  60 . The individual screws  64  are held in place by a flexible plastic strip  62 . As can be seen in  FIG. 1 , this collated strip sub-assembly  60  can run along the entire length of the screw feed guide rail  50  from the rear area of the housing portion  20  toward the front end portion  30  of tool  10 . The screws  64  are fed directly along the screw feed guide rail  50  within a guiding slot that is discussed below in greater detail. As the screws traverse through the slot portion of the screw feed guide rail  50 , they are ultimately directed toward the front end of the tool until each of the screws reaches a “drive” position at  66 . When viewing the tool  10  at its front-most portion (i.e., the left-hand portion as viewed in  FIG. 1 ), the left-most screw  64  has been indexed to the drive position at  66 , and thus is now essentially co-linear with the main drive components of the portable tool  10 . As the collated screw sub-assembly  60  is moved through the screw feed guide rail  50 , the plastic strip  62  will eventually make contact with a sprocket (not visible in  FIG. 1 ) that acts as a rotary indexer, and which is located inside the slide body sub-assembly  34 . The sprocket moves each of the portions of the plastic strip  62  into a proper rotary position so that their attached screws  64  eventually end up in the front-most drive position  66 . 
   When the nose piece  32  is actuated by being pressed against a workpiece (not seen in  FIG. 1 ), then a drive bit (not visible in  FIG. 1 ) will move in a linear fashion to push the screw at  66  into the workpiece, and the drive bit will also then be turned in a rotary motion to twist the screw at  66  in the normal manner for driving a screw  64  into a solid object. Once the screw at  66  has been successfully driven into the solid object, then the tool  10  is withdrawn from the surface of the solid object, and of course the screw  64  remains behind and has now broken free from the plastic strip  62 . In one mode of the invention, the tool  10  will now be free to allow the sprocket to perform its rotary indexing function and to bring forth the next screw  64  into the front-most drive position at  66 . This type of screw-feed actuation can be referred to as “indexed on return,” since the “lead screw” is moved into the “firing position” at  66  as the nose piece  32  is released (or “returned”) from the surface of the workpiece. 
   The tool  10  can also be configured in an alternative screw-feed actuation mode, in which the lead screw is moved into the firing position at  66  as the nose piece  32  is pressed against the surface of a workpiece; this type of screw-feed actuation can be referred to as “indexed on advance.” If tool  10  is configured for indexed on advance, then the lead screw would not yet be in the position at  66  (as seen on  FIGS. 1 ,  2 , and  4 ) at the moment the nose piece  32  is “relaxed” in its non-firing state. Instead, the lead screw is not indexed into the firing position at  66  until the nose piece  32  is “pushed in” (or “advanced”) toward the main body portion of the tool  10  (e.g., toward the handle portion  40 ), which is a state of the tool illustrated in  FIG. 5 , and discussed below in greater detail. Note that the indexed on advance configuration is a preferred mode of operation for tool  10 . 
   It will be understood that both the indexed on advance and indexed on return screw-feed actuation modes of operation can work equally well with the movable guide  50  of the present invention. Other possible modes of screw-feed actuation might be developed in the future that would also work well with the movable guide  50  of the present invention. 
   Referring now to  FIG. 2 , the portable tool  10  is seen from its side, and the gripping surfaces  42  and  48  are seen as being relatively continuous along the back portion (to the right in the view of  FIG. 2 ) of the tool  10 . A human user will typically use both hands to hold the tool  10  in place while it is being actuated to drive a screw into an object. One of the user&#39;s hands can be placed on the top surface  42 , while the other user&#39;s hand can grasp the handle portion  40  at the lower gripable surface  48 , while also actuating the trigger  44 . 
   Referring now to  FIG. 3 , the front end portion  30  of the tool is illustrated in greater detail, so that some of the features of the slidable screw feed guide rail  50  can be seen. In  FIG. 3 , the collated strip sub-assembly  60  is only partially loaded into the screw feed guide rail  50 , so that the details of the front portions of the guiding rail  50  can be better seen. As can be seen in  FIG. 3 , the collated strip sub-assembly  60  has the flexible plastic strip  62  indexed up to a front portion of the slidable screw feed guide rail  50 , just past a bend  56  in the screw pathway of the screw feed guide rail  50 . A wear plate  54  is included within the open area (e.g., a slot) through which the collated strip  60  passes, as the strip  60  approaches the front open area  70  that is the end of the guiding pathway through which the screws pass in the screw feed guide rail  50 . The “delivery” area of the screw guide pathway is indicated at  72 , and as the flexible plastic strip  62  exits along the wear plate  58 , it then encounters the slide body sub-assembly  34 , and the plastic strip  62  continues along an open area (or slot)  74  in the slide body sub-assembly  34 . The slide body sub-assembly  34  includes a pair of guide surfaces  76  that guide the shank of the individual screws  64  as they pass along the slide body sub-assembly  34 , as they are being indexed toward the front-most “drive” position at  66 . 
   In  FIG. 4 , the collated strip sub-assembly  60  has now been indexed all the way to the front of the tool  10 , such that its furthest-most screw  64  has been indexed to the drive position  66 . The individual segments of the plastic strip  62  are visible in  FIG. 4 , since a portion of the “left” rail half  52  is partially cut-away in this view. The screw at  66  will be driven through the opening in the front surface  36  of the movable nose piece  32 . In  FIG. 4 , it can be seen that the collated strip sub-assembly  60  will hold the screws  64  in place while the lead screw at  66  will be driven into a solid workpiece, which occurs when the movable nose piece  32  is pushed against the workpiece surface. When that occurs, nose piece  32  will be pushed toward the upper-right corner in  FIG. 4 , and the slide body sub-assembly  34  as well as the screw feed guide rail  50  will all move in accordance with this movement of the nose piece  32 . This keeps the collated screw sub-assembly  60  in a relatively intact and non-movable position with respect to the sliding guide rail  50 , and thus the system will tend to keep the screws  64  from becoming misaligned during the firing procedure of the tool  10 . 
     FIG. 5  illustrates the firing position in which the movable nose piece  32  has been depressed with respect to the overall housing portion  20 . The entire guide rail  50  and collated screw sub-assembly  60  have also been moved back (which is toward the upper-right area in  FIG. 5 ). The slide body sub-assembly  34  is not visible in  FIG. 5 , because it is now behind the feed tube  26  and front housing outer shell structure  22 . 
   Referring now to  FIG. 6 , the slidable guide rail  50  is illustrated in a side view, to show some of the construction features thereof. The “left” rail half  52  is visible since it is facing the viewer, and the protrusion or tang  82  is now visible. The screw feed guide rail  50  includes a mounting pin  80  that is positioned within an opening of the slide body sub-assembly  34  when the guide rail  50  is attached to the tool  10 . The bend or elbow  56  is readily seen in  FIG. 6 . Reference numeral  70  refers to the guiding pathway (or slot) through which the collated strip of screws moves. 
   Referring now to  FIG. 7 , some of the other features of the screw feed guide rail  50  are visible, including the “front” delivery end of the guiding pathway or slot at  72 , as well as a “rear” entry end of the same slot at  78 . The “left” tang  82  is visible as it protrudes from the left rail half  52 . A “right” tang  84  is visible from the inside of the “right” rail half  54 . The wear plate  58  is visible, and is adjacent to a bottom slide surface  86  that is formed as part of the guiding pathway or slot that starts at the rear entry end  78  and exits at the front delivery end  72  of the guide rail  50 . The protrusions or tangs  82  and  84  slide along a pair of interior linear slots (not shown on  FIG. 7 ) within the front housing  22  of the tool  10 . 
   By inspecting the figures hereof, it can be seen that the collated screw sub-assembly  60  will be well retained within the guiding slotted areas (i.e., the pathway) of the slidable screw feed guide rail  50 , and the exit end (or delivery end) at  72  will guide the flexible plastic strip  62  and deliver that plastic strip directly to the slide body sub-assembly  34 . This keeps the screws  64  from becoming tangled or bunched, or otherwise becoming misaligned during the operation of the tool  10 . 
   In one configuration of the present invention, a plurality of small arcuate protrusions (not visible in the figures) are provided along at least a portion of the guiding pathway (or slotted area)  70  of the slidable screw feed guide rail  50 . These protrusions can increase the mechanical resistance against the side edges of the flexible plastic strip  62 , and thereby help prevent this strip  62  from too easily advancing along the slot or pathway  70 . The larger the fasteners (e.g., screws)  64  that are part of the collated strip  60 , the more likely that the increased weight of these larger fasteners will tend to push one of the fasteners of the collated strip  60  past the front indexing position; if that occurs, then a fastener may not stop at the correct position (i.e., at the firing position  66 ), and such fastener might push past the firing position  66  and remain in the flexible plastic strip  62 . Of course, that would be an undesirable result. 
   The arcuate protrusions can be made in several different forms (i.e., they don&#39;t necessarily need to be arcuate), and can even be movable, if desired, to act as movable detent guide positioning devices. In one mode of the present invention, the arcuate protrusions are located along both sides of the slot/pathway  70 , and are positioned between the elbow  56  and the entry area at  78 . These protrusions (or “bumps”) can be manufactured as part of a molded plastic guide rail half (e.g., one of the halves  52  or  56 ), and they can extend throughout the entire slot/pathway  70 , or for only a portion of this slot/pathway, if desired. 
   It will be understood that the principles of the present invention are applicable to many different types of fastener driving tools, including tools powered by AC electrical power (e.g., 120 VAC line power from an outlet), DC electrical power (e.g., from a battery or a solar panel), a pneumatic power source, or a hydraulic power source, for example. In other words, the prime mover device  68  could comprise an electric motor, a pneumatic motor, or a hydraulic motor, for example. In addition, the types of fasteners that can be driven in the manner of the present invention are not limited to screws, but could instead be nails or rivets, for example. 
   Some of the components used in the present invention have been disclosed in a commonly-assigned patent, titled “Screw Feed and Driver for a Screw Driving Tool, U.S. Pat. No. 5,988,026, which is assigned to Senco Products, Inc., and which is incorporated herein by reference in its entirety. Some portions of the present invention have also been disclosed in another commonly-assigned patent, titled “Screw Driving Tool,” U.S. Pat. No. Des. 462,001, which is assigned to Senco Products, Inc., and which is incorporated herein by reference in its entirety. 
   It will be understood that the term “collated screw sub-assembly” as used herein refers to a strip of screws that are temporarily mounted in a flexible strip of material that exhibits openings and other structures to hold the screws in place until they are needed. In many products, the flexible strip of material comprises plastic, but other materials could be used, if desired. The individual screws are advanced to a driving position in a screw driving tool (such as portable tool  10 ), and each screw is individually driven from the flexible strip by the tool when the tool is actuated. 
   It will also be understood that the principles of the present invention are applicable to many different types of fastener driving tools, including tools powered by AC electrical power (e.g., 120 VAC line power from an outlet), DC electrical power (e.g., from a battery or a solar panel), a pneumatic power source, or a hydraulic power source, for example. In addition, the types of fasteners that can be driven in the manner of the present invention are not limited to screws, but could instead be nails or rivets, for example. 
   All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. 
   The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Any examples described or illustrated herein are intended as non-limiting examples, and many modifications or variations of the examples, or of the preferred embodiment(s), are possible in light of the above teachings, without departing from the spirit and scope of the present invention. The embodiment(s) was chosen and described in order to illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to particular uses contemplated. It is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Technology Category: 7