Abstract:
A portable hand-held screw driving tool is provided for use with collated strips of screws. A collated strip of screws enters from the “bottom” area of the tool and runs through a fixed guide along a front area of the tool&#39;s handle, and then to a movable slide body having a rotatable sprocket that receives the collated strip, and indexes the strip so a screw can be driven by the tool. Between the slide body and the fixed guide is a flexible strap with a bracket that places tension on the collated screw strip, which prevents the flexible collated strip from becoming substantially misaligned (e.g., bunching, sagging, or becoming tangled) in the area between the fixed guide and the slide body. The collated strip is kept sufficiently taut, regardless of the orientation of the screw driving tool with respect to the ground.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application claims priority to provisional patent application Ser. No. 60/516,947, titled “Tensioning Device for Collated Screw Driving,” 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 “bottom” area of the tool, and keeps a sufficient amount of tension on the flexible collated strip so as to prevent the strip from becoming substantially misaligned, such as by sagging, or otherwise bunching up or becoming tangled, before the strip reaches the screw-driving front position of the tool. The collated strip is kept sufficiently taut, regardless of the orientation of the screw driving tool with respect to the ground, as a source of gravity. 
   The screw driving tool has a fixed guide along a front area of its handle, through which the collated strip of screws passes; the tool also has a slide body in its front or “nose” area, and a rotatable sprocket receives the collated strip for positioning the screws in a proper location and orientation for being driven into a solid object. Between the slide body and the fixed guide is a flexible strap with a bracket that places tension on the collated screw strip, and prevents the strip from becoming substantially misaligned, such as by bunching or sagging in the area between the fixed guide and the slide body. 
   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 “bottom feed” tools, in which a flexible collated strip of screws was fed from the bottom 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 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. This tangling/bunching phenomena can occur when the collated screws have been fed into a slide body mechanism, and once the driving mechanism has been actuated, the screws will 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 the earlier tools sold by Senco, the collated strip of screws did not tend to readily become bunched or tangled during drive sequences of the tool, for two main reasons: (1) the screws were shorter and were not very heavy, and (2) the distance between the guide portion of the handle and the nose piece of the tool was fairly short, thereby providing a lesser distance within which the collated strip could possibly become bunched or tangled, or otherwise sag. Examples of such screw driving tools that have been available in the past are Senco Tool Model No. DS 162-14V and Senco Tool Model No. DS200-14V. 
   It would be an improvement to provide a 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 provide a means for preventing the collated strip from sagging or otherwise bunching or tangling. 
   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 bottom portion 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 guide member as part of a handle portion of the tool that initially feeds a flexible collated strip of screws therethrough, and then passes the collated strip of screws toward a front or nose portion of the tool, while also providing a tensioning device to prevent 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 guide member of a bottom handle region of the tool, feeds that flexible collated strip of screws toward a front driving portion of the tool, and provides a flexible strap with a bracket to provide tension on the flexible collated strip of screws to prevent the strip of screws from becoming substantially misaligned, e.g., from substantially sagging, bunching, or becoming tangled. 
   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 2–3 inches and which are heavier than shorter 1–2 inch screws, and which guides the collated strip through a fixed guide member on the handle portion of the tool toward a front or nose portion of the tool, and which provides a flexible strap that runs between the fixed guide and the nose portion of the tool, and which prevents the flexible collated strip of 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 tensioning device for a portable fastener-driving tool is provided, in which the fastener-driving tool exhibits: (i) a housing; (ii) a handle attached to the housing; (iii) a first guide member proximal to the handle, for receiving and guiding a collated strip of fasteners; (iv) a fastener driving area at one end of the housing; and (v) a fastener indexing portion proximal to the fastener driving area, for receiving the collated strip of fasteners and moving a fastener of the collated strip of fasteners to a driving position; and wherein the first guide member and the fastener indexing portion are spaced-apart from one another; and in which the tensioning device comprises: (a) a longitudinal strap having a first end and a second end, wherein the first end is in communication with the fastener indexing portion, and the second end is in communication with the first guide member; and (b) a second guide member that is attached to the strap and is capable of receiving the collated strip of fasteners, the second guide member being positioned between the first and second ends of the strap. 
   In accordance with another aspect of the present invention, a portable fastener-driving tool is provided, which comprises: (a) a housing containing a driving mechanism; (b) a handle attached to the housing; (c) a first guide member proximal to the handle, the first guide member having a first opening and a second opening, the first guide member being capable of directing a collated strip of fasteners between the first and second openings; (d) a fastener driving area at one end of the housing; (e) a fastener indexing portion proximal to the fastener driving area that is capable of receiving the collated strip of fasteners and moving a fastener of the collated strip of fasteners to a driving position; (f) wherein, when actuated, the driving mechanism operates to drive a fastener at the driving position from the collated strip of fasteners; (g) wherein the first guide member and the fastener indexing portion are spaced-apart from one another, and (h) wherein the collated strip of fasteners traverses a distance between the first guide member and the fastener indexing portion; and (j) a tensioning device, comprising: (i) a longitudinal strap having a first end and a second end, wherein the first end is in communication with the fastener indexing portion, and the second end is in communication with the first guide member; and (ii) a second guide member that is attached to the strap and is capable of receiving the collated strip of fasteners, the second guide member being positioned between the first and second ends of the strap; wherein: when the collated strip of fasteners is positioned within both the first guide member and the second guide member, and is in communication with the fastener indexing portion, a combination of the strap and the second guide member prevents the collated strip of fasteners from becoming substantially misaligned in a region between the first guide member and the fastener indexing portion. 
   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 side elevational view of a portable hand-held screw driving tool that accepts a flexible collated strip of screws from a bottom portion of the tool, as constructed according to the principles of the present invention. 
       FIG. 2  is a perspective view from the front and opposite side of the screw driving tool of  FIG. 1 , showing further details of the screw driving tool without the collated strip of screws. 
       FIG. 3  is a side elevational view in partial perspective, showing the screw driving tool of  FIG. 1  in a partial cross-section view. 
       FIG. 4  is a perspective view of a flexible strap and slide body sub-assembly, which is used on the tool of  FIG. 1  to provide tension on the flexible collated strip of screws. 
       FIG. 5  is a perspective view from the side and slightly from above and behind of the flexible strip and slide body sub-assembly of  FIG. 4 , and also showing details of the retainer parts that hold the flexible strap to the slide body sub-assembly. 
       FIG. 6  is a perspective view from below and somewhat from the front of the flexible strap used to provide tension on the flexible collated strip of screws used with the tool of  FIG. 1 . 
       FIG. 7  is a side elevational view of the screw driving tool of  FIG. 1 , depicted in a vertical working position in its “relaxed” non-firing mode before being pressed against a work surface. 
       FIG. 8  is a side elevational view of the screw driving tool of  FIG. 1  depicted in a vertical working position and in its actuated, firing position as the nose piece is pressed against a work surface. 
   

   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 hand-held screw driving tool, generally designated by the reference numeral  10 , that includes a housing portion  20 , a front end portion  30 , a handle portion  40 , and a screw feed portion  50 . Screw driving tool  10  is designed for use with a flexible strip of collated screws, and in  FIG. 1 , the flexible collated screw strip sub-assembly is generally designated by the reference numeral  60 . 
   The housing portion  20  of the tool includes a front housing outer shell structure  22 , and a rear housing portion that has a top gripping surface  24  as well as a bottom gripping surface (or set of surfaces)  42 , that are also part of the handle portion  40 . Toward the front of housing portion  20  is a feed tube  26 , that houses some moveable portions of the tool  10 , as discussed below. In the illustrated embodiment, the feed tube  26  is fixedly attached to the internal mechanical mechanisms contained within housing portion  20 . 
   The front end portion  30  includes a moveable 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 moveable in a longitudinal direction of the tool  10 , and when the nose piece  32  is pressed against a solid object, the screw driving tool  10  will be actuated to physically drive one of the screws into the solid object, also 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 the nose piece can be re-positioned for different lengths of screws. The nose piece  32  has a plurality of screw length positioning holes  38 , which are used to attach nose piece  32  to the slide body sub-assembly  34  at different relative positions to one another. 
   Handle portion  40  includes a set of bottom gripping surfaces  42  that can be used by a person&#39;s hand to readily grip the handle and not easily slide along the bottom surface of the housing portion  20 . Handle portion  40  also includes a trigger  44 , which is used to actuate an electrical switch to operate the internal drive mechanisms of the hand-held portable tool  10 . In the illustrated embodiment, a battery sub-assembly  46  is attached at the bottom area of handle portion  40 , which provides electrical power to the internal drive mechanism of the tool  10 . 
   Handle portion  40  also includes a curved guide member  48  that can receive a flexible collated strip of screws, in this case the collated screw sub-assembly  60 . The collated screw sub-assembly  60  mainly consists of a plastic strip  62  that has several openings to receive individual screws  64 . The overall collated screw sub-assembly is flexible to a certain degree, as can be seen in  FIG. 1  by the curved orientation of the plastic strip  62  as it is fed through the guide  48  and up toward the nose piece  32  and the slide body sub-assembly  34 . 
   Much of the mechanical mechanisms described above for the portable screw driving tool  10  has been available in the past from Senco Products, Inc., including such tools as the Senco Model Nos. DS162-14V and DS200-14V. 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. 
   With regard to the present invention, a flexible strap  54  is provided which runs between an attachment point in the slide body sub-assembly  34  and into an opening of the guide  48 . Strap  54  provides both mechanical strength and a sliding surface for the plastic strip  62  of the collated screw sub-assembly  60 . Attached to the more forward position of the strap  54  is a bracket  52 . This bracket is shaped to receive the plastic strip  62  and to allow the screws  64  to have their shanks pass through an opening in the bracket  52  as the collated screw sub-assembly  60  passes toward the slide body sub-assembly  34 . Further details of this construction are provided below. 
   Referring now to  FIG. 2 , some of the mechanical details of the portable screw driving tool  10  can be better seen in this view without the collated screw sub-assembly. In  FIG. 2 , there are several ventilation slots  28  that can be seen in the side of the tool housing, below the top gripping surface  24 . This allows ventilating air to help cool the motor and other mechanical components therewithin. 
   Also more easily seen in  FIG. 2  are the details of some of the shapes of the bottom guide  48 , which has a curved surface toward the front portions of the tool  10 . The guide  48  includes a vertical member  70  that extends between the curved portion of the guide  48  to the uppermost portion of the guide, along the bottom surface of the front housing  22  of the tool  10 . The curved portions of the guide  48  are actually divided into two halves, in which the two halves are generally designated by the reference numerals  72  and  74 . As seen in  FIG. 2 , the guide half  72  is the “left” guide half, while the other guide half is the “right” guide half  74 ; this is from the front perspective of the tool  10 . Between these two guide halves  72  and  74  is an open slot  76 , which is used to guide the shanks of the individual screws  64  as they move along the guide&#39;s pathway toward the front nose piece  32  and slide body sub-assembly  34 . 
   Additional details of the strap  54  can also be seen in  FIG. 2 . The bracket  52  is seen as having openings to allow the plastic strip  62  portion of the collated screw sub-assembly  60  to pass through the bracket  52 . Further details of this will be described below. Strap  54  protrudes into an open top area at  78  of the guide  48 . Strap  54  is attached to the slide body sub-assembly at a pivot link, which uses a hinge pin  56 . Further details of this construction are discussed below. As will be seen in later views, the plastic strip  62  of the collated screw sub-assembly  60  will slide along the strap  52 , through the bottom guide  48 , through a portion of the bracket  52 , and up to the front areas of the slide body sub-assembly  32 . 
   Referring now to  FIG. 3 , some of the internal components of the portable screw driving tool  10  are illustrated. An electric motor  80  is positioned within the housing at the rear-most portion of the tool  10 . Motor  80  drives into a gearbox  82 , which in turn drives a clutch drive member  84 . A clutch driven member  86  is selectively engaged by the clutch drive member  84  when it is time to drive a screw. 
   When viewing the tool at its front-most portion (i.e., the left-hand portion as viewed in  FIG. 3 ), it can be seen that one of the screws has been indexed to a “drive” position at  66  and is now co-linear with the main drive components of the portable tool  10 . As the collated screw sub-assembly  60  is moved through the various “guided” pathways, the plastic strip  62  will eventually make contact with a sprocket  90  that acts as a rotary indexer, which moves each of the portions of the plastic strip  62  into a proper position so that their attached screw  64  eventually ends up in the front-most drive position  66 . 
   When the nose piece  32  (not seen in  FIG. 3 ) is actuated by being pressed against a workpiece (not seen in  FIG. 3 ), then a drive bit  88  will move in a linear fashion to push the screw at  66  into the workpiece, and the drive bit  88  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 broken free from the plastic strip  62 . The tool  10  is now free to allow the sprocket  90  to perform its rotary indexing function and to bring forth the next screw  64  into the front-most drive position. 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  FIG. 3 ) 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. 8 , 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 flexible strap  54  and bracket  52  of the present invention. Other possible modes of screw-feed actuation might be developed in the future that would also work well with the flexible strap  54  and bracket  52  of the present invention. 
   Referring now to  FIG. 4 , a front portion of the strap  54  is illustrated, as it is attached to the slide body sub-assembly  34 . Strap  54  is connected by a pivot link hinge pin  56  to a pivot link member  94 , which fits into the slide body sub-assembly at an opening  92  in the slide body sub-assembly  34 . The details as to the attachment of the pivot link  94  to the slide body sub-assembly  34  are discussed below. 
   The slide body sub-assembly  34  is also comprised of two separate halves at its front-most areas. The two halves are designated by the reference numerals  96  and  98 , and they provide a guide surface for the shanks of the screws as they are being moved forward to the final drive position (at  66 , illustrated in  FIG. 3 ). Strap  54  also has the bracket  52  attached thereto, and as discussed above, this bracket has an open area and some guide surfaces that assist in guiding the plastic strip  62  of the collated screw sub-assembly  60 . This will also be discussed below in greater detail. 
   Referring now to  FIG. 5 , the slide body sub-assembly  34  and strap  54  are once again illustrated, this time from a different angle as compared to that depicted in  FIG. 4 . A small portion of the pivot link  94  is visible where it connects to the hinge pin  56  in  FIG. 5 . Another portion of the pivot link  94  is visible at  106 , which comprises the arcuate end of this pivot link  94 . 
   There are several openings in the slide body sub-assembly  34  in the side facing the viewer of  FIG. 5 . One of these openings is a square-shaped opening at  104 . A retaining pin has a square “head” portion  100  that fits into the square-shaped opening  104 . The retaining pin also includes a rod portion  102 , in which the rod  102  fits within the arcuate-shaped opening of the end  106  of the pivot link  94 . This is the mechanism that holds the pivot link  94  mechanically with the slide body sub-assembly  34  in the illustrated embodiment. The retaining pin is held in place by the nose piece  32  when it is installed to the slide body sub-assembly  34 . 
   Since the arcuate surface of the pivot link at  106  fits around the rod  102  of the retaining pin, the pivot link  94  can rotate or pivot about the centerline axis of the rod  102 . The hinge pin  56  also allows the pivot link to rotate or pivot about the end portion of the strap  54 . The different orientations thereby enabled with this construction will allow the strap  54  and slide body  34  to move along a linear pathway inside the feed tube  26  as the nose piece  32  is depressed when it is placed against a solid object that is going to have a screw driven thereinto. The different possible angular orientations of the pivot link  94  with respect to other portions of the tool  10  are better illustrated in  FIGS. 7 and 8 . This will be discussed below in greater detail. 
   Referring now to  FIG. 6 , the entire strap  54  with bracket  52  and pivot link  94  are illustrated as a single sub-assembly. The arcuate front member of the pivot link  94  is easily seen at  106  in this view. The hinge pin  56  is also easily seen, as it connects into an end portion of the strap  54 . 
   Some of the details of bracket  52  are now illustrated, and will now be discussed in detail. Bracket  52  includes a rear opening  110  and a front opening  112 . The plastic strip  62  of the collated screw sub-assembly  60  passes through these openings, when the plastic strip  62  is being indexed toward the front of the tool  10 . These openings  110  and  112  are formed by two guide members formed in the bracket  52 . Each guide member forms one-half of two guiding surfaces, which are designated by the reference numerals  114  and  116 . The outer edges of the plastic strip  62  will run through these guide surfaces  114  and  116 . 
   As can been seen in  FIG. 6 , the bracket  52  has an angled member  118  near the rear opening  110 . This allows the rear opening  110  to be flared so that it can receive (and pass through) the plastic strip  62  from a variety of angles. It also allows the human user to install a plastic strip  62  more easily into the rear opening  110  of the bracket  52 , as the tool  10  is first being “loaded” with a collated screw sub-assembly  60 . 
   The strap  54  illustrated in  FIG. 6  exhibits a bend at  120 , and a curved or arcuate portion at  122 . Such a bend is useful, but is not necessarily critical to the proper working of the strap  54  in the present invention. Furthermore, if a bend is to be placed in the strap  54 , it could be placed at different positions, if desired, for different tool sizes and screw sizes that will be provided in a collated screw sub-assembly  60 . Moreover, any bend in the strap  54  could also be made at a different angle, if desired. The overall tool shape and dimensions will tend to help determine the more useful bend angle and location along the strap  54 . 
   The curved member  122  of the strap  54  is designed to more readily fit through the curved portion of the guide  48  that is part of the handle portion  40  of the tool  10 . Depending upon how flexible or inflexible the strap  54  is to be made, this curved member  122  could be relatively stiff or relatively limber, depending on the designer&#39;s choice. It will be understood that the strap  54  should exhibit enough stiffness to support the weight of the collated screw sub-assembly  60  in the area between the front portion  70  of the guide  48  and the rear opening  110  of the bracket  52 . This will achieve one of the advantages of the present invention, which is to prevent the collated strip sub-assembly  60  from substantially sagging or bunching, or otherwise allowing the screws  64  to become tangled because of some type of misalignment in the collated screw sub-assembly  60  that might otherwise occur. 
   Referring now to  FIG. 7 , the tool  10  is illustrated as being oriented in a vertical manner, ready to be pressed against a solid object  130 , such as a patio deck for example. In this orientation, the weight of a lengthy screw  64  might tend to sag the plastic strip  62  of the collated screw sub-assembly  60 . As can be seen in  FIG. 7 , the plastic strip  62  runs through the guide bracket  52 , and runs mainly parallel to the strap  54 . Strap  54  runs into the open area of the curved guide  48  of the handle portion  40 . Bracket  52  and the strap  54  provide a tension on the collated screw sub-assembly  60 , and thus will not allow the plastic strap  62  to substantially sag or otherwise bunch up. 
   While  FIG. 7  depicted the tool  10  in a relaxed or “non-firing” position,  FIG. 8  illustrates the tool  10  in its “firing” position, in which the nose piece  32  has been placed against the solid object  130  and pressed down such that the nose piece  32  has slid linearly upward in  FIG. 8  inside the feed tube  26 . Since feed tube  26  is fixedly attached to the front housing  22 , the solid surface  130  cannot come any “closer” than the front of the feed tube  26 , as seen in  FIG. 8 . In this position, a screw (at position  66 ) will be driven into the solid object  130 . 
   In this position, the entire slide body sub-assembly  34  will also have moved linearly upward (in this vertical orientation), and the strap  54  and guide  52  will also have been moved toward the top of this  FIG. 8 . However, the bracket  52  is pivotally mounted to the slide body sub-assembly  34 , as discussed above, and now has a different angular orientation with respect to slide body sub-assembly  34 . The plastic strip  62  of the collated screw sub-assembly  60  will have also moved upward in this view, but will not have allowed its screws  64  to become substantially tangled or otherwise bunched up because of the bracket  52 . In this activated or firing position, the screw fastener manageability is maintained throughout the driving sequence. Since the tensioning device assembly  52 / 54  is not fixed to the housing  22 , the movable portion of the system is free to slide backward in the feed tube  26 , and also to advance the next screw without a malfunction. The feed system will automatically index the next screw  64  while maintaining the screw strip integrity. 
   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 term “flexible strap” as used herein refers to a piece of material that is much longer in its longitudinal direction than its width in a transverse direction that is perpendicular to the longitudinal axis. In one embodiment of the present invention, the strap comprises metal, but other materials could be used, if desired. The strap should be flexible enough to allow itself to be somewhat bent or straightened as the screw driving tool is actuated to drive a screw into a solid material; however, the strap should also be strong enough to support the weight of the collated screw sub-assembly in various orientations, so that the collated screws do not cause the strap to unduly deform. 
   It will be further 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.