Abstract:
A fastener driving tool includes a driver having a driver shaft extending therefrom, a first extension member operably connected to the driver and a second extension member operably connected to the first extension member. The tool is for use on roof deck panels. The second extension member slidingly engages the first extension member between a loading position and a driving position. A bearing assembly operably connects the first and second extension members. The bearing assembly is formed from a non-metallic, low-friction material. A portion of the bearing assembly is mounted to one of the first and second extension members for sliding engagement with the other extension member and is disposed to prevent direct contact of the first and second extension members with one another. A fastener receiving member is mounted to the second extension member for receiving fasteners when in the loading position and for supporting and releasing the fasteners when in the driving position. The fastener receiving member includes a cradle having a main body portion and a pair of legs extending from the main body portion diverging downwardly and outwardly. The cradle is configured for positioning on the roof panel, straddling raised portions of the panel for aligning the tool therealong.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention pertains to a fastener driving tool having improved bearing and guide assemblies. More particularly, the present invention pertains to a fastener-driving tool having non-metal contacting bearing assemblies and an enhanced aligning nosepiece guide assembly.  
           [0002]    Fastener driving tools are well known in the art. Such tools are typically powder-actuated or electric-actuated tools for driving fasteners through a surface, such as a metal deck or metal roof The fasteners that are driven are of a known type that include a shank having a self-tapping, self-driving or self-drilling tip at one end and head integral with the other end of the shank. Typically, a sealing washer is positioned on the shank with an interference fit.  
           [0003]    Known fastener-driving tools generally include a driver such as a powder actuated or an electric-actuated driver that is mounted to telescoping tubes. A first tube (upper or outer tube) is stationary relative to the driver and a second (lower or inner tube) telescopes relative to the upper tube. A shaft is mounted to the driver and extends through the tubes. The lower tube telescopes relative to the upper tube to permit movement of the driver shaft relative to a distal end of the lower tube. An end of the shaft includes, for example, a hex or socket-like element to engage the fastener head for driving. The lower tube telescopes to permit movement between a retracted position and a contracted position. In the retracted or extended position, a fastener is loaded onto an end of the shaft for driving into the surface. In the contracted position, the fastener is driven from the tool outwardly, through the distal end of the lower tube, into the surface.  
           [0004]    Known fastener driving tools include a spring positioned between the tubes to urge the tubes and thus the tool into the retracted or loading position. In known driving tools, the lower tube is fitted immediately within the upper tube. Although this assures proper alignment of the tubes relative to one another and straight movement of the fastener, there is surface-to-surface contact of the tubes. In that these tubes are formed of metal this produces metal-to-metal contact between the tubes and can result in high frictional forces and possibly binding of the tubes.  
           [0005]    Generally, a stop is positioned on the end of the upper tube that cooperates with a stop positioned along the length of the lower tube. This limits that travel of the tubes relative to one another and assures that the fastener is properly driven into the surface. That is, the stops are positioned relative to one another so that the fastener is driven a predetermined amount into the surface.  
           [0006]    Known fastener driving tools include a nosepiece assembly that supports the fastener prior to and as it is engaged by the driver shaft (e.g., socket-like element). An opening in the nosepiece provides a track or path through which the fastener is driven from the tool. One drawback to known nosepiece assemblies is that while the nosepiece is relatively large, the opening through which the fastener is driven is relatively small. In that some types of roofing systems have preformed holes for receiving the fasteners, it is only with skill, practice and close inspection that the fastener opening is properly aligned with the roof deck panel hole. Other types of roofing systems require fastening roof panels, without these preformed holes, to one another and/or to underlying structural members.  
           [0007]    In addition, many such metal roofing systems are formed having a corrugated profile defined by “peaks” and “valleys”. For those systems that have the preformed holes, the holes are typically formed on the peak portion of the corrugations. This makes it even more difficult to align the tool while maintaining it balanced on top of the corrugation while driving the fastener.  
           [0008]    Accordingly, there is a need for a fastener driving tool that has an improved bearing surface to eliminate the problems associated with metal-to-metal sliding tube contact. Desirably, such a tool includes an enhanced fastener aligning and guide assembly to facilitate proper positioning of the fastener over the surface into which the fastener is driven. Most desirably, these enhanced features are provided in a tool that permits the tool operator to use the tool standing in an erect or near-erect stance to reduce operator fatigue.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    A fastener driving tool for driving fasteners into a workpiece is for use by an operator in a substantially erect position. The tool is configured for use on roof panels to drive fasteners into the panels for panel to panel and panel to structural applications. The panels have a corrugation-like profile defining a peak, a pair of valleys adjacent to the peak and respective walls extending between the peak and the adjacent valleys. Holes may be pre-formed in the panels, along the peak, for fastening the panels to the underlying structure or for joining panels to one another.  
           [0010]    The tool includes a driver, such as an electric motor, telescopic extension members and a fastener receiving member. The telescopic extension members permit driving the fasteners into the roof panel. The fastener receiving member receives a fed fastener, supports the fastener during loading and releases the fastener as it is driven into the roof panel.  
           [0011]    The driver has a driver shaft extending therefrom. The first extension member is operably connected to the driver and the second extension member is operably connected to the first extension member. In a current embodiment, the extension members are formed as tubes, with the first tube being a upper tube and the second member being a lower tube. The lower tube slidingly engages the upper tube between a loading position to load fasteners into the tool and a driving position to drive the fasteners from the tool into the roof panels.  
           [0012]    A bearing assembly operably connects the upper and lower tubes. The bearing assembly is formed from a non-metallic, low-friction material, such as an acetal resin. A portion of the bearing assembly is mounted to one of the upper and lower tubes for sliding engagement with the other tube. The bearing assembly is positioned to prevent direct contact of the tubes with one another.  
           [0013]    In one embodiment, the bearing assembly includes an upper tube bearing mounted to a lower end of the upper tube for slidingly engaging the lower tube. Preferably, the upper tube bearing including a sleeve portion mounted to the upper tube and a bearing portion extending transverse to and inwardly of the sleeve portion for contact with the lower tube.  
           [0014]    The bearing assembly can further include a driver shaft guide mounted to the lower tube at about an upper end thereof. The driver shaft guide carries an upper tube bearing surface for slidingly engaging the upper tube. The upper tube bearing surface and the upper tube bearing maintain the upper and lower tubes concentric with one another during use.  
           [0015]    The fastener receiving member receives fasteners when in the loading position and supporting and releases the fasteners when in the driving position. The fastener receiving member is mounted to the lower tube. The fastener receiving member includes a cradle having a main body portion and a pair of legs extending from the main body portion diverging downwardly and outwardly from the main body, symmetrical to one another.  
           [0016]    The main body defines an upper inside surface extending between and contiguous with the legs, and an opening through the main body portion for passage of the fastener. The cradle is configured for positioning on the panel, straddling the peak with the upper inside surface resting adjacent the peak and the legs extending into the valleys for aligning the opening in the main body portion with a desired location on the roof panel (e.g., the panel hole).  
           [0017]    In one embodiment, the cradle includes an aligning member having a jaw assembly that includes first and second jaw pivotal jaw elements mounted thereto. The jaw elements pivot between a closed position wherein the jaw elements abut one another and support a fastener and an open position wherein the jaw elements are pivoted away from one another by the fastener driven therethrough. The jaw elements are mounted to the cradle by pivot pins.  
           [0018]    Preferably, an upper guide is mounted to the cradle. The upper guide is movable between a loading position that corresponds to the closed position of the jaw elements and a driving position that corresponds to the open position of the jaw elements. The upper guide includes a locking member for interfering with pivoting of the jaw elements when the upper guide is in the loading position and for disengaging from the jaw elements when the upper guide is in the driving position.  
           [0019]    The jaw elements are configured each defining one-half of a cone. When together, the jaw elements define a nadir. In a current embodiment, the nadir extends through the cradle opening beyond the upper inside surface, so that the nadir rests on a desired location (e.g., “falls” into a roof panel hole).  
           [0020]    Alternately, the cradle is formed having a viewing opening formed in at least one of the legs. An aligning marker can be formed as a stylus that extends inwardly of the viewing opening or as indicia on the one of the legs.  
           [0021]    These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0022]    The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:  
         [0023]    [0023]FIG. 1 is a front view, shown in partial cross-section, of a fastener driving tool embodying the principles of the present invention showing the tool in the retracted or loading position, in which the outer tube bearing is shown engaging the inner tube stop in phantom lines;  
         [0024]    FIGS.  2 A- 2 C are partial, enlarged cross-sectional views of the fastener driving tool of FIG. 1, the partial figures shown for ease of illustration;  
         [0025]    [0025]FIG. 3 is a front view of one embodiment of a nosepiece assembly for use with the fastener driving tool, which nosepiece assembly embodies the principles of the present invention;  
         [0026]    [0026]FIG. 4 is a side view of the nosepiece assembly of FIG. 3;  
         [0027]    [0027]FIG. 5 is a cross-sectional view of the nosepiece assembly taken along line  5 -- 5  of FIG. 4;  
         [0028]    [0028]FIG. 6 is a side view of another nosepiece assembly illustrating and alternate nosepiece cradle; and  
         [0029]    [0029]FIG. 7 is a front view of the cradle of FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]    While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described presently preferred embodiments with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed and claimed herein.  
         [0031]    Referring now to the figures and in particular to FIG. 1, there is shown a fastener driving tool  10  embodying the principles of the present invention. The tool  10  includes, generally, a driver  12  such as the illustrated electric, rotating driver  12 . An outer, upper tube  14  is fixedly mounted to the driver  12  by, for example, the exemplary illustrated clamp  16 . The upper tube  14  is mounted to the driver  12  at a driver cap assembly  18 .  
         [0032]    A lower, inner tube  20  is telescopically mounted to the upper tube  14 . The lower tube  20  slides freely within a lower portion of the upper tube  14 , as will be described in more detail below. A bottom or distal end  22  of the lower tube  20  terminates at a juncture, as indicated at  24 , with a feed tube  26 . The feed tube  26  is mounted to the lower tube  20  for feeding individual fasteners F through the feed tube  26  into the distal end  22  of the lower tube  20 . A nosepiece assembly  28  is mounted to an end  30  of the tool  10  at about and adjacent the juncture  24  of the feed tube  26  and lower tube  20 . The nosepiece assembly  28  supports the fasteners F as they are fed into the lower tube  20  and are driven from the tool  10 .  
         [0033]    A driver shaft  32  extends from the driver  12  through the upper and lower tubes  14 ,  20 . A bottom end of the driver shaft  32  includes a fastener engaging element  34 , such as the illustrated hexagonal socket-like element for engaging the fastener F head. When the tool  10  is in the retracted (i.e., loading) state, as seen in FIGS. 1 and 2A, the fastener engaging element  34  extends just beyond the distal end  22  of the lower tube  20 . This positioning facilitates loading the fastener F. When the tool  10  is in the contracted (i.e., driving) state, the fastener engaging element  34  extends into the nosepiece assembly  28  to drive the fastener F from the tool  10  into the workpiece.  
         [0034]    A driver shaft guide  36  is positioned at and mounted to an upper end  38  of the lower tube  20 . The guide  36  includes an inner circumferential shoulder  40 . A driver shaft bearing  42  is mounted on the inner shoulder  40  providing a bearing surface for the driver shaft  32 . The guide  36  further includes an outer shoulder  44  at an outer periphery, generally opposing the inner shoulder  40 . A spring  46  is positioned and extends between the outer shoulder  44  and the driver cap assembly  18 . The spring force is exerted against the lower tube  20  (by connection to the guide  36 ) and the driver cap  18 , thus biasing the tubes  14 ,  20  into the retracted state. In a current embodiment, the guide outer shoulder  44  includes a spring seat bearing  48  for engaging the spring  46 . The spring seat bearing  48  includes an upper tube bearing surface  50  for slidingly engaging the upper tube  14 .  
         [0035]    In a present embodiment, the driver shaft guide  36 , driver shaft bearing  42  and outer shoulder portion/spring seat bearing  44 / 48 , including the outer tube bearing surface  50 , are formed from a suitable, low friction polymeric material, such as DELRIN®, which is commercially available from E. I. du Pont de Nemours and Company. DELRIN® is an acetal resin based material (more particularly polyoxymethylene) that exhibits numerous advantageous characteristics, including high tensile strength, impact resistance, and stiffness, as well as fatigue endurance, resistance to moisture and chemicals, dimensional stability and natural lubricity. Those skilled in the art will recognize other suitable materials for use in the present invention, which other materials are within the scope and spirit of the present invention.  
         [0036]    As described above, the feed tube  26  is joined with the lower tube  20  at the distal end  22  of the lower tube  20 . As best seen in FIG. 2A, the feed tube  26  enters the lower tube  20  at an angle so that the fasteners F traverse smoothly from the feed tube  26  into the nosepiece  28 . Referring to FIG. 2B, a feed tube mount  52  is positioned on the lower tube  20  and secures the feed tube  26  to the lower tube  20 . The feed tube mount  52  includes a pair of fasteners  54  that extend through an opening  56  in the wall of the upper tube  14  and into the drive shaft guide  36 .  
         [0037]    Unlike known fastener driving tools, the present tool  10  includes an upper tube bearing assembly  58  mounted to the upper tube  14  for guiding that tube  14  along the lower tube  20 . The bearing  58  is mounted to an outer surface  60  of the upper tube  14  and includes a sleeve portion  62  and a bearing portion  64 . In a current embodiment, the bearing portion  64  extends from an end of the sleeve portion  62  generally transverse thereto and contacts the lower tube  20 . In one configuration, the sleeve portion  62  is threadedly mounted to the upper tube  14  at threaded region  66 . In a present embodiment, the upper tube bearing  58  is also formed from an acetal resin, such as DELRIN(, or a like suitable, low friction material.  
         [0038]    Referring now to FIGS. 1 and 2B, the bearing assembly  58 , shown cross-hatched, illustrates the bearing  58  when the tool  10  is in the retracted or loading position. The bearing assembly  58  shown non-cross-hatched at  58   a  illustrates the bearing  58  when the tool  10  is in the contracted or driving position. It must also be noted that although the bearing assembly  58  appears to be of a split arrangement, it in fact is not. That is, the bearing halves symmetrically oppose one another and form a single bearing with a single, circular (not skewed or elliptical) bearing portion  64 .  
         [0039]    The sleeve portion  62  includes an outer collar  68  having a groove  70  formed therein into which one or more pliable spheres  72  are fitted to maintain the sleeve portion  62  in a predetermined location along the upper tube threads  66 . In a current embodiment, the spheres  72  are also formed from a polymeric material, such as DELRIN® acetal resin. An O-ring  74  can be positioned around the spheres  72  to maintain the spheres  72  securely in place along the upper tube threads  66 .  
         [0040]    As can be seen from FIGS. 1 and 2B, a gap  76  is defined between the upper and lower tubes  14 ,  20 . The gap  76  spaces the tubes  14 ,  20  from one another to prevent metal-to-metal contact between the tubes  14 ,  20 . The gap  76  is maintained annular by the bearing portion  64  of the upper tube bearing assembly  58  (which is mounted to the upper tube  14  and contacts the lower tube  20 ) and the driver shaft guide  36  upper tube bearing surface  50 . In this manner, the upper and lower tubes  14 ,  20  are maintained spaced from one another by a pair of longitudinally spaced, circumferential bearing surfaces  50 ,  64  that assure that the tubes  14 ,  20  are maintained concentric with one another along their lengths. In addition to the spacing provided, these bearing surfaces  50 ,  64  provide low friction, non-binding movement of the tubes  14 ,  20  relative to one another. This arrangement further assures that there is no metal-to-metal contact between the upper and lower tubes  14 ,  20  during operation of the tool  10 .  
         [0041]    Stops  76  are fixed to an outer surface of the lower tube  20  distally from the upper tube bearing  58 . The stops  76  cooperate with and engage the bearing portion or leg  64  of the upper tube bearing  58  to set a predetermined amount of travel d of the lower tube  20  relative to the upper tube  14 . The amount or distance of travel d is set by threadedly engaging the upper tube bearing  58  along the threaded region  66  of the upper tube  14 . This predetermined amount of travel d limits the travel of the driver shaft  32  and fastener engaging element  34  into the nosepiece  28 , and subsequently, the distance that the fastener F is driven out of the tool  10  into the workpiece. As will be appreciated from a study of the drawings, the distance that the fastener F is driven by the tool  10  is set by the distance or travel d between the upper tube bearing  58  and the stops  76 . As will also be appreciated by those skilled in the art, it is important that the fasteners F be driven into the workpiece surface (such as a roofing deck) a predetermined amount. Under-driving the fastener results in improperly securing the roof deck panels to one another, while over-driving the fastener can result in an improper seal between the fastener and the roof deck panels.  
         [0042]    In a present tool  10 , the travel or distance d can be set between 3.125 inches and 3.625 inches. This corresponds to the depth to which commonly used roofing deck fasteners are specified to be driven. As set forth above, this travel is set by threadedly engaging or disengaging the upper bearing assembly  58  from the upper tube threads  66 . It will be recognized by those skilled in the art that variations can be made to the tool  10  to provide one or more different ranges of travel for the tool  10 , which other ranges are within the scope and spirit of the present invention.  
         [0043]    Referring now to FIGS.  3 - 5 , there is shown one embodiment of a fastener receiving member or nosepiece assembly  28  embodying the principles of the present invention. The nosepiece assembly  28  is mounted to the fastener discharge end of the tool  10  at about the juncture  24  of the feed tube  26  and the lower tube  20 . The nosepiece  28  is configured to receive a fastener F and to guide and align the fastener F into proper position to be driven.  
         [0044]    The nosepiece  28  includes a lower guide or cradle  80 , an upper guide  82  and a nosepiece tube  84 . The cradle  80  is configured to rest on the roof panel (as indicated at R in FIG. 4) to straddle a corrugation. The upper guide  82  and nosepiece tube  84  are fixedly mounted to each other. The nosepiece tube  84  inserts into the distal end  22  of the lower tube  20  and includes an elongated opening  86  in the side wall of the tube  84  that aligns with the feed tube  26  so that fasteners F fed from the feed tube F are directed into the nosepiece tube  84 . An O-ring  88  can be positioned on the nosepiece tube  84 , between the upper guide  82  and the lower tube distal end  22  to reduce rattle of the tool  10  during use.  
         [0045]    The upper guide  82  and nosepiece tube  84  are mounted to the cradle  80  for reciprocal movement within the cradle  80  between a loading position and a driving position, which positions correspond to the loading and driving positions of the tool  10 , generally. A pair of springs  90  are disposed between the upper guide  82  and the cradle  80  to bias the upper guide  82  into the loading position.  
         [0046]    A pair of opposing jaw elements  92  are pivotally mounted to the cradle  80 . The jaws  92 , when in a closed position, support the fastener F and when open, pivot outwardly to permit driving the fastener F into the workpiece (e.g., roof panel R). A pair of pivot pins  94  extend through the cradle  80  for pivotal movement of the jaws  92 .  
         [0047]    The upper guide  82 , as set forth above, is mounted to the cradle  80  for reciprocal movement. A pair of elongated slots  96  are formed in the upper guide  82 , through which the pivot pins  94  traverse. In this manner, the upper guide  82  reciprocates within the cradle  80 , along the pivot pins  94 , independent of the jaws  92 .  
         [0048]    The upper guide  82  further includes a pair of roll pins  98  mounted thereto that are configured to cooperate with the jaws  92 . The roll pins  98  move with the upper guide  82  to move into and out of interfering engagement with the jaws  92 . To this end, when the upper guide  82  is in a retracted position and the jaws  92  are closed, the roll pins  98  engage a camming shoulder  100  on each respective jaw  92  to maintain or lock the jaws  92  closed. When the upper guide  82  is urged downwardly to the driving position, the roll pins  98  are moved out of engagement with the camming shoulders  100  which permits the jaws  92  to pivot outwardly to open. The jaws  92  are, however, biased closed by a pair of return springs  102 . The force of the fastener F against an inner surface  104  of the jaws  92  urges the jaws  92  open when the roll pins  98  are disengaged from their respective jaw camming shoulders  100 . In this manner, the jaws  92  are maintained closed until they are “unlocked” by movement of the roll pins  98  off of the camming shoulders  100  (by downward force on the upper guide  82 ) and urged or forced open by the fastener F being driving through the jaws  92 , out of the nosepiece  28  and into the workpiece.  
         [0049]    As can be seen from FIG. 5, the jaws  92  are configured having a split arrangement. Each half of the split jaw arrangement defines one-half of a downwardly oriented conical element  106 . The conical element  106  halves, when mated, terminate at a nadir  108 . The nadir  108  is disposed slighting below an upper inside surface  110  of the cradle  80  so that as the tool  10  is moved along the surface of the roof panel R, the nadir  108  will essentially drop into the preformed hole (if provided) in the roof panel R. As will be recognized by those skilled in the art, this provides rapid and sure tool  10  alignment over a desired location on the roof panel R.  
         [0050]    The cradle  80  includes a central, main body portion  112  and a pair of legs  114  diverging downwardly and outwardly therefrom. The cradle  80  is configured to rest on and engage a corrugation of the metal roof panel R, with the upper inside surface  110  of the cradle  80  resting on the peak of the corrugation, the legs  114  extending downwardly along the sides of the corrugation, and the leg bases  116  resting on or in the valleys of adjacent corrugations. As such, the cradle  80  is held secure against the deck panel R corrugation. In this manner, the cradle  80  is self-centering along the corrugation peak.  
         [0051]    The present cradle  80  provides for readily aligning the tool  10  along the corrugation peak so that the fasteners F are properly driven into the roof panel R. In use, the tool  10  is slid along the roof panel R with the cradle  80  engaging a corrugation peak. When traversing the tool along the roof panel R, it is in the loading condition with the tubes  14 ,  20  and nosepiece  28  retracted. When the jaw nadir  108  “falls” into a roof panel R hole, the tool  10  is stood upright and a fastener F is fed into the feed tube  26 . The fastener F is fed by gravity to the nosepiece  28 . A downward pressure is then applied to the driver  12  handle. The downward pressure moves the upper and lower tubes  14 ,  20  into the contracted or driving position which engages the fastener engaging element  34  with the fastener F head. Continued downward pressure urges the nosepiece assembly upper guide  82  down to “unlock” the jaws  92 . As further downward pressure is applied to the driver  12  handle and as the driver  12  is actuated, the fastener F is urged though the jaws  92  and is driven into the roof panel R.  
         [0052]    Those skilled in the art will recognize that the types of metal roof systems available vary. To this end, not all roof panels are formed wit preformed openings along the panel corrugation peaks. As such, the present tool  10  can be use such that the nadir  108  is used to position the tool  10  along the corrugation peak, at a desired location on the roof panel R.  
         [0053]    An alternate cradle  180  is illustrated in FIGS.  6 - 7 . This cradle  180  can be used with or without the nosepiece assembly illustrated in FIGS.  3 - 5 . The cradle  180  includes a central, elongated bore  182  through which the fastener F travels as it is driven from the tool  10 . As seen in FIG. 6, each of the legs  184  includes an opening or viewing window  186  therein. The viewing windows  186  each extend through inner and outer surfaces  188 ,  190  of the legs  184  and through a portion of the main body  192 . To this end, when the cradle  180  is resting on a corrugation of the roof panel R the corrugation peak is readily visible through the viewing windows  186 . In addition, in that the present tool  10  is configured for use by an operator standing erect or relatively erect, the viewing window  186  is configured so that central portion of the corrugation peak is readily viewed by the operator standing slightly off-center of the tool  10  when it is positioned for use. As such, there is no longer a need for an operator to constantly crouch and stand while driving fasteners F into the roof deck R.  
         [0054]    The cradle  180  is further provided with aligning markers  194 , such as styli or engraved indicia to align the cradle  180  and thus the tool  10  over the desired location on the panel R (e.g., over the preformed roof panel R holes). The styli  194  can be, for example, wire  196  mounted to the cradle legs  184  by screws, bolts or other mechanical fasteners, such as indicated at  198 . The aligning markers  194  permit properly visually aligning the tool  10  on the roof panel R (e.g., immediately above the roof panel R hole) to properly drive the fastener F. Similar to the cradle  80  illustrated in FIGS.  3 - 5 , this embodiment of the cradle  180  straddles the roof panel R corrugation and is thus self-centering over the roof panel R corrugation.  
         [0055]    Those skilled in the art will recognize that a variety of different types of aligning markers  194  and aligning devices can be used to assure that the tool is properly aligned on the roof panel R. All such aligning devices are within the scope and spirit of the present invention.  
         [0056]    In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.  
         [0057]    From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.