Abstract:
A Framing Rafter Square Attachment. The attachment cooperates with a conventional rafter or framing square to make the repetitive cutting of lengths of framing lumber (such as for blocking) much easier and faster to accomplish. The attachment allows the position of the framing square as held by the attachment to be adjustable so that it can accommodate a wide variety of circular saw fence configuration. The attachment is extendable and retractable so that the attachment has both a compact size for storage, while at the same time being able to accommodate longer cuts. A drag clip may be provided to allow the user to selectively pinch a piece of wood with the attachment so that the pinched piece of wood can then be repositioned for another cut without the user having to set down either the circular saw or the attachment. Finally, the attachment has a subassembly that allows the user to easily cut a piece of lumber to fit a preexisting length or opening.

Description:
This application is filed within one year of, and claims priority to Provisional Application Ser. No. 60/898,862, filed Jan. 31, 2007. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates generally to wood working tools and fixtures and, more specifically, to a Framing Rafter Square Attachment. 
   2. Description of Related Art 
   The invention that is the subject of the present application is an advancement of that invention described in U.S. Pat. No. 6,604,296, issued Aug. 12, 2003, by the same inventor. 
   The product known as a “Speed Square™” is in wide use by virtually every professional framer (individuals whose expertise is in constructing structures from wood framing material). An example of the conventional Speedsquare™ attached to the attachment of the present invention is shown in  FIG. 1  and labeled as item  110  therein. The Speed Square™  110  is designed to be used to permit a framer to rapidly make precise cuts (typically cross-cuts) in framing material using a conventional electric handheld circular saw. The conventional use of a Speed Square™  110  is well-disclosed in the &#39;296 patent, and therefore will not be repeated herein. 
   While the device of the &#39;296 is a great advancement beyond the prior art of the time, there were a few advancements that have been discovered since the creation of that device. First, the board feeding mechanism/assembly needed additional thickness resolution so that it could accommodate limitless thickness of boards within the range of boards typically used for blocking. Next, a side boundary for the boards being fed was needed in order to further stabilize boards while they were being fed. Third, refinement of the extension member and locking device mechanism was appropriate. Fourth, it was determined that a “cut to fit” option would be desirable so that the worker could cut precise blocking to custom framing bays. Finally, the entire attachment assembly of the &#39;296 attachment need to be revised so that high volume production could be attained. 
   SUMMARY OF THE INVENTION 
   In light of the aforementioned problems associated with the prior devices, it is an object of the present invention to provide a Framing Rafter Square Attachment. The attachment should work with a conventional rafter or framing square to make the repetitive cutting of lengths of framing lumber (such as for blocking) much easier and faster to accomplish. The attachment should allow the position of the framing square to be adjustable so that can accommodate a wide variety of circular saw fence configurations. The attachment should further be extendable and/or retractable so that the attachment has both a compact size for storage, while at the same time being able to accommodate longer cuts. A drag clip should be provided to allow the user to selectively pinch a piece of wood with the attachment so that the pinched piece of wood can then be repositioned for another cut without the user having to set down either the circular saw or the attachment. Finally, the attachment should provide a subassembly that allows the user to easily cut a piece of lumber to fit a preexisting length or opening. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which: 
       FIG. 1  is a front perspective view of the framing rafter square attachment of the present invention; 
       FIG. 2  is a rear perspective view of the attachment of  FIG. 1 ; 
       FIG. 3  is a front exploded perspective view of the attachment of  FIGS. 1 and 2 ; 
       FIG. 4  is a top view of the attachment of  FIGS. 1-3 ; 
       FIG. 5  is a right side view of the attachment of  FIGS. 1-4 ; 
       FIG. 6  is a left side view of the attachment of  FIGS. 1-5 ; 
       FIG. 7  is a front view of the attachment of  FIGS. 1-6 ; 
       FIG. 8  is a back view of the attachment of  FIGS. 1-7 ; and 
       FIG. 9  is a bottom view of the attachment of  FIGS. 1-8 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Framing Rafter Square Attachment. 
   The present invention can best be understood by initial consideration of  FIG. 1 .  FIG. 1  is a front perspective view of the framing rafter square attachment  100  of the present invention. The Framing Rafter Square Attachment  100  of the present design has three main parts: the main frame  1  (also referred to as the main frame assembly), the second retaining channel  21 , and the extension bar  32 . The framing square  110  slides into and is adjustable along the first retaining channel  70  that is positioned longitudinally in the main frame  1 . This allows the framing square  110  to be slid along the length of the main frame until it is at a zero point on the measurement scale which can be seen more clearly in  FIG. 3 . Zeroing the framing square  110  refers to adjusting the square&#39;s positioning along the first retaining channel  70  to cooperate with the particular circular saw being used to take into account the specific fence dimensions of the saw, such that when a cut is made using the attachment  100  with the saw&#39;s fence against the square  110 , the cut will be at “zero” on the measuring scale. 
   One substantial improvement of this new design is that the peg  123  of the prior design has been replaced with an assembly that is adjustable for different thicknesses of wood. Instead of a peg there is now a roller sleeve  13  extending outwardly from the main frame  1  that is adjustable up and down along the support roller slot  52 . Also, a side roller sleeve  15  extends upwardly from the end of the roller sleeve  13  to provide an additional side restraint to the wood when the user is feeding pieces of wood into the attachment  100  for the next cut. 
   The second retaining channel  21  attaches to the main frame  1  through a spring-loaded attachment mechanism that can be seen clearly in  FIG. 3  as well. The stop block  41  is slideable along a length of the second retaining channel  21  so that it can be positioned for the appropriate length of cut. The stop block clamp knob  43  can be tightened or loosened to position and then secure the stop block  41  at the desired position. If a cut is desired that is to result in a piece that is longer than can be provided by only the length of the second retaining channel  21 , then the extension bar  32  can be extended out the necessary amount from the end of the second retaining channel  21 . When the extension bar  32  is at the desired position, the latch lever  27  will hold the extension bar  32  in place. If we now turn to  FIG. 2 , we can examine another advantage of the present design. 
     FIG. 2  is a rear perspective view of the attachment  100  of  FIG. 1 . From the back side of the attachment  100  we can see the support roller knob  20  which is provided to allow the roller sleeve  13  to be secured once it is positioned along the support roller slot  52  in the desired location. Furthermore, there is a square clamp knob  3 , which threadedly engages an aperture formed in the main frame  1 . This will allow a user to secure the framing square  110  in its desired position. 
   One significant advancement of the cutout design is that it provides the user with the ability to cut a piece of wood to fit an existing bay between studs, joists or rafters. This is accomplished through operation of a pair of gauge faces extending from the back side of the attachment  100 . The first gauge face  58  extends backwardly from the stationary gauge block  54  and the second gauge face  60  extends backwardly from the moveable gauge block  56 . The user need simply position the first gauge face  58  against one side of the bay to be sized to cut to fit, and the moveable gauge block  56  which is integrated with the stop block  41  is then slid along the length of the second retaining channel  21  until the second gauge face  60  is against the stud or joist defining the other side of the (cut-to-fit) stud hay. Through the cooperative arrangement of the elements of the attachment  100 , if the user then positions the end of the piece of wood at the stop block  41  and cuts as guided by the framing square  110 , the wood block that results will be the length that is identical to the distance between the first gauge face  58  and the second gauge face  60 . If we now turn to  FIG. 3 , we can examine all of the critical elements of this design. 
     FIG. 3  is a front exploded perspective view of the attachment  100  of  FIGS. 1 and 2 . Beginning with the main frame assembly  1 , the support roller knob  20  threadedly engages the end of the support roller shaft  4 , which extends through the supper roller slot  52  discussed in  FIG. 1 . The support shaft base member  5  includes an indicator pointer that is used to set the support roller shaft at the size of the different types (thicknesses) of dimensional lumber. A drag clip  6  is located at the base end of the support roller shaft and is provided to create additional resistance when the user desires to feed the wood into the attachment  100 . In order to do so, it is a simple matter of tilting the attachment  100  so that the drag clip  6  pinches the piece of wood to be fed. The user can then pull the piece of wood longitudinally (for example, to the right in this view) by simply pulling the handle  129  to the right. When a sufficient length of wood has been fed, the user simply tilts up the attachment  100  until the drag clip  6  no longer pinches against the piece of wood, after which the attachment  100  can be slid easily to the left until the end of the piece of wood is in contact with the stop block  41 . In this manner, the user can hold the handheld circular saw in their right hand and the attachment  100  in their left hand and repeatedly feed and cut, feed and cut an entire series of wood blocks without the need for repositioning of the attachment or the saw or the wood block through separate motion. 
   At the end of the support roller shaft  4 , a collar  18  holds the roller sleeve  13  and bushing  9  securely on the shaft  4 . Furthermore, the collar  13  has a threaded aperture formed in its periphery into which a side roller shaft  14  threadedly engages. The side roller shaft  14  retains a side roller sleeve  15 , which is positioned to prevent the attachment  100  from inadvertently sliding off the side of the piece of wood during the cutting or feeding processes. The collar  18  is held on the support roller shaft by a thumb screw  17  which allows the user to tighten and loosen the collar in order to reposition the side roller sleeve  15  or to disassemble the roller sleeve assembly. 
   The second retaining channel  21  attaches to a pair of apertures  72  formed on the right side of the main frame assembly  1 . A pair of pegs  36  are inserted through apertures formed in the second retaining channel  21  which then engage specialty apertures  72  formed in the main frame assembly  1 . The apertures  72  are wider than they are high (i.e. they are oval in shape), such that a small amount of longitudinal travel can be permitted to prevent the saw from jamming while cutting. The spring  39  and block  38  create tension against one side of the apertures  72  for the pegs  36  to prevent the retaining channel  21  from rattling or feeling loose to the user. At the same time, if the saw blade begins to jam, the spring  39  and block  38  will permit the second retaining channel  21  to move (to the right in this view), thereby eliminating the blade pinch. 
   The stationary gauge block  22  attaches to the left or proximal end of the retaining channel  21 . There is a first measuring scale  26  displayed on the top surface of the second retaining channel  21 . The first measuring scale  26  provides the scale to which the stop block  41  is set to achieve the desired length of piece of wood after the cut. 
   The extension bar  32  is slideably accepted within the second retaining channel  21  in order to provide additional length when desired so that longer pieces of wood can be cut. A second measuring scale  35  is provided on the top surface of the extension bar  32 . The mechanism that locks the extension bar  32  in place is the latch lever  27 . The latch lever  27  is a fulcrum-like lever where in one end is biased downwardly by a spring  31 , which forces the stop pin  28  upward and against the bottom of the extension bar  32 . There may be depressions formed at regular intervals on the bottom of the extension bar  32  such that the tip of the stop pin  28  will actually lock the second measuring scale in place at predetermined graduations. In the current embodiment there are only depressions to lock the extension bar  32  in either the fully retracted or fully extended position. The stop pin  28  pressure upwardly against the extension bar  32  is sufficient to hold the extension bar  32  in any user-set extension condition. 
   The stop block assembly is designed to slide over and along the length of the second retaining channel  21 . It comprises a stop block  41  on the front side of the second retaining channel  21  which is attached to a moveable gauge block  40  on the back side of the second retaining channel  21 . The stop block clamp knob  43  is how the stop block  41  is positioned along the length of the second retaining channel, and then locked in place. If the extension bar  32  is extended, the stop block  41  can be slid along the extension bar  32 , and beyond the end of the second retaining channel  21  to be set at a distance that is demarcated on the second measuring scale  35  for cutting longer pieces of wood. If we now turn to  FIG. 4 , we can examine the other aspects of this design. 
     FIG. 4  is a top view of the attachment  100  of  FIGS. 1-3 . As shown here, the stop block  41  which is depicted on the left side of the drawing is positioned along the length of the second retaining channel  21  to create a distance between the first gauge face  58  and the second gauge face  60  that is the custom cut-to-fit length. As discussed above in connection with  FIG. 2 , this length can be set by the user such at the piece of wood can be cut to exactly match the custom cut-to-fit length. Now turning to  FIG. 5  we can see the device from yet another view. 
     FIG. 5  is a right side view of the attachment  100  of  FIGS. 1-4 . Here in  FIG. 5  we see that the support shaft  4  supports the side roller sleeve  15  as well as the roller sleeve  13  to create a convenient support structure for feeding additional lumber through the attachment  100  while keeping it closely aligned underneath the U-shaped area to be cut. 
     FIG. 6  is a left side view of the attachment  100  of  FIGS. 1-5  and  FIG. 7  is a front view of the attachment of  FIGS. 1-6 .  FIGS. 6 and 7  show how the drag clip is positioned when the attachment  100  is in use. The drag clip  6  is normally slightly below and to the side of the top surface of the roller sleeve  13 . If, however, the user rotates the device  100  in direction R the top surface of the drag clip  6  will reach above the top surface of the roller sleeve  13  which will create a pinching force on the lumber. This, then, will allow the user to feed the lumber ahead for the next cut by sliding the attachment  100  in direction F. Once the end of the lumber is sufficiently fed the attachment  100  is rotated counterclockwise until it is level and the device is moved in direction L until the end of the lumber is in contract with the stop block  41 . At this point the circular saw fence can be placed against the framing square  110  and the out can be made. 
     FIG. 8  is a back view of the attachment of  FIGS. 1-7 . This view of the attachment  100  to depict the mold details of the main frame  1 . These details are provided simply to show an example of a preferred arrangement of structural fins. 
   Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. 
   
     
       
             
           
             
             
           
         
             
               TABLE I 
             
             
                 
             
             
               PARTS LISTING 
             
             
               ITEM 
             
             
                 
             
           
           
             
                 
             
           
        
         
             
               1 
               3001 Main Frame Assembly EA 
             
             
               2 
               3001-50 Nameplate EA 
             
             
               3 
               3002 Knob, Square Clamp EA 
             
             
               4 
               3005-010-01 Roller Support Shaft EA 
             
             
               5 
               3005-010-02 Support Shaft Mount EA 
             
             
               6 
               3005-010-03 Drag Clip EA 
             
             
               7 
               3005-010-04 Roll Pin, 3/32 × ⅞ EA 
             
             
               8 
               3005-010-05 Washer, ¼″ EA 
             
             
               9 
               3005-020 Reducer Axle Bushing EA 
             
             
               10 
               3005-040 Washer, ½″ EA 
             
             
               11 
               3005-042 ½″ Self Lock Retaining Ring EA 
             
             
               12 
               3005-044 ½″ Vinyl Cap EA 
             
             
               13 
               3005-050-01 Roller-2″ EA 
             
             
               14 
               3005-090 Shoulder Bolt EA 
             
             
               15 
               3005-100 Side Roller EA 
             
             
               16 
               3005-110 Washer, #10 EA 
             
             
               17 
               3005-120 ¼-20 Thumb Screw EA 
             
             
               18 
               3005-130 Collar Mount EA 
             
             
               19 
               3006 Washer, ¼″ EA 
             
             
               20 
               3007 Knob, Support Shaft EA 
             
             
               21 
               3009-010 Channel EA 
             
             
               22 
               3009-020 Wearplate Cap EA 
             
             
               23 
               3009-030 Screw, Wearplate, #6-32 EA 
             
             
               24 
               3009-050 Screw, Stop Plate, #4-40 EA 
             
             
               25 
               3009-040 Extension Bar Stop Plate EA 
             
             
               26 
               3009-060 Channel Scale EA 
             
             
               27 
               3009-070-01 Latch Lever EA 
             
             
               28 
               3009-070-02 Stop Pin EA 
             
             
               29 
               3009-070-03 Retaining Ring EA 
             
             
               30 
               3009-080 Pivot Pin EA 
             
             
               31 
               3009-090 Latch Spring EA 
             
             
               32 
               3011-010 Extension Bar EA 
             
             
               33 
               3011-020 End Block EA 
             
             
               34 
               3011-030 Screw, End Block, #6-20 EA 
             
             
               35 
               3011-040 Extension Bar Scale EA 
             
             
               36 
               3014 Overload Shaft EA 
             
             
               37 
               3018 Pin, Retainer Block EA 
             
             
               38 
               3016 Spring Retainer Block EA 
             
             
               39 
               3017 Overload Spring EA 
             
             
               40 
               3019-010-02 Gauge Plate EA 
             
             
               41 
               3019-010-01 Stop Block EA 
             
             
               42 
               3019-010-03 Screw, Stop Block, #6-19 EA 
             
             
               43 
               3020 Knob, Stop Block EA 
             
             
               44 
               3025 Knob Spacer EA 
             
             
               46 
               3030 Clamp Plate EA 
             
             
               47 
               3040 End Cap, Extension Bar EA 
             
             
               48 
               3050 Screw, End Cap, #6-20 EA 
             
             
               49 
               3060 6″ Rafter Square (Optional) EA