Patent Publication Number: US-7913729-B2

Title: Molding coping fixture

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/597,308, filed on Nov. 22, 2005, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to fitting of moldings, and more specifically to a coping cuts made to fit moldings together at inside corners, and even more specifically to a fixture for making coping cuts in moldings. 
     DESCRIPTION OF THE RELATED ART 
     Coping the inside corner of molding, such as baseboard moldings, chair rails, quarter round, and the like, entails cutting the profile of the molding into the end grain of one of the moldings. This cutting process in known as coping. The piece that receives the cut, the coped piece, helps push and hold the adjoining piece against the wall and into the corner when the pieces are installed. The result is a well fit corner that will not be affected by expansion and contraction of the wood. 
     Traditionally, coping cuts are made by hand. To accurately make coping cuts, a skilled woodworker is required, as these cuts require a fairly high skill level. In most cases, this skill level is beyond the “do-it-yourselfer”. 
     Some attempts to simplify or mechanize the process of making coping cuts have been made. One product currently commercially available is called the “COPEMASTER”. This large and expensive device works in a manner similar to key cutting and duplicating machines. First, a template is made on the machine by moving a carriage having a specially designed circular saw blade in a particular direction. This template is then locked into a vice, where a stylus traces the template and the saw cuts a molding based on the movement of the stylus against the template. There are several drawbacks to the “COPEMASTER” device. This device is a large, expensive, stand alone power tool. The size and weight of the COPEMASTER makes it inconvenient for use portable use, such as at a job site. Because the COPEMASTER has its own custom designed saw blade and saw motor to go along with the carriage assembly and stylus, the COPEMASTER is priced out of the range of the typical home project hobbyist. 
     Another tool designed to assist in making coping cuts is called “THE COPER”. To use this device, a user must first create a template from a piece of the molding to be coped. The template is created from a two part epoxy mixture by placing a piece of the molding into a tray and then casting the profile of the molding into the epoxy. Before use, the template must be allowed to fully harden, which can take several hours. Once hardened, the template is fastened into a clamping jig and used to guide a router bit along the end of the molding to be coped. Because of the time needed to create the template, “THE COPER” is inconvenient for coping moldings of different types, such as base molding and quarter-round, as part of one project. 
     Neither of the devices mentioned above effectively prevent “tear-out” of wood or material in the molding being coped. “Tear-out” is the peeling, tearing, or splitting out of wood fibers from the molding being coped. Tear-outs occur most often at the end of the cut, which typically is the top and most visible portion of the molding. Tear-out can lead to unsightly blemishes in the molding. 
     In view of the deficiencies cited above, there remains a need for an improved coping fixture. Thus, it would be advantageous to provide a coping fixture that is versatile, easy to use, portable, and reduces or eliminates tear-outs. 
     SUMMARY 
     It is an object of the present invention to provide an improved coping fixture. 
     It is a further object of the present invention to provide a coping fixture that is versatile, easy to use, portable, and reduces the occurrence of tear-outs 
     It is a further objective of the present invention to provide a coping fixture where a user can select the desired angle of said coping cut. 
     The present invention is a molding coping fixture. According to the present invention, the coping fixture includes a plurality of shims, where the shims can be adjusted to conform to a profile of a molding to be coped, the shims are secured into the fixture and maintain the profile during a coping cut by a router. The coping fixture according to the present invention also includes an anti-tear-out device to prevent tear-out of material from the molding during the coping cut. In various preferred embodiments, some or all of the anti-tear-out device may be replaceable. The coping fixture according to the present invention also includes a fixture for selectively adjusting the angle of the coping cut. In various preferred embodiments, a guide pin passes along the shims and a router bit secured in a fixed relation to the guide pin performs the coping cut while the guide pin passes along the shims. 
     Other features and advantages of the invention will be apparent from the following detailed description taken in conjunction with the following figures, wherein like reference numerals represent like features. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  shows a top view of a coping fixture according to the present invention. 
         FIG. 1B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 2  shows a side view of a coping fixture according to the present invention. 
         FIG. 3A  shows a front view of a coping fixture according to the present invention. 
         FIG. 3B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 3C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 3D  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 3E  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 4A  shows a router guide platform as part of a coping fixture according to the present invention. 
         FIG. 4B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 4C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 5A  shows an exploded view of a router mount plate as part of a coping fixture according to the present invention. 
         FIG. 5B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 5C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 5D  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 5E  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 6  shows an assembled view of a router mount plate as part of a coping fixture according to the present invention. 
         FIG. 7  shows a bottom exploded view of a router mount plate adapted to hold a guide pin in alignment with a cutting bit as part of a coping fixture according to the present invention. 
         FIG. 8  shows a bottom assembled view of a router mount plate as shown unassembled in  FIG. 7  as part of a coping fixture according to the present invention. 
         FIG. 9  shows a front view of a coping fixture according to the present invention. 
         FIG. 10A  shows front, top and side views of a work piece platform of a coping fixture according to the present invention. 
         FIG. 10B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 10C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 11A  shows top and side views of a router stand for use in conjunction with a coping fixture according to the present invention. 
         FIG. 11B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 11C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 11D  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 12A  shows top and side views of a quarter round holding fixture for use in conjunction with a coping fixture according to the present invention. 
         FIG. 12B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 12C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 13A  shows top, side, and front views of a height gauge for use in conjunction with a coping fixture according to the present invention. 
         FIG. 13B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 13C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 14A  shows side and bottom views of a sliding block and sliding block rod of a coping fixture according to the present invention. 
         FIG. 14B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 14C  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 14D  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 15A  shows side and top views of a shim for use in a coping fixture according to the present invention. 
         FIG. 15B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 16A  shows an extension block of a coping fixture according to the present invention. 
         FIG. 16B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 17A  shows an anti-tear-out ramp of a coping fixture according to the present invention. 
         FIG. 17B  shows another view of an aspect of the coping fixture of according to the present invention. 
         FIG. 17C  shows another view of an aspect of the coping fixture of according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is susceptible of embodiments in many different forms, there are shown in the drawings and will herein be described in detail, preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. 
     The present invention is a molding coping fixture.  FIG. 1A  shows a top view of a coping fixture according to the present invention.  FIG. 2  shows a side view of a coping fixture according to the present invention.  FIG. 3A  shows a front view of a coping fixture according to the present invention. The various structures and components of a coping fixture according to the present invention can be explained in relation to their use during operation of the coping fixture. 
     To begin operation of a coping fixture according to the present invention, a sample section of the molding to be coped is needed. Preferably, this sample section is on the order of one inch in length. The sample section will be used to set the profile of the molding to be coped into the shims  13 . 
     To set the profile into the shims  13 , knob  20  is loosened and anti-tear-out fixture  22  is removed and shim set up platform  27  is installed. The shim set up platform pin  28  mates with a corresponding hole in the rotating dovetail block  11 . When in place, shim set up platform  27  is under the sliding block  12  and the shims  13 . On top of shim set up platform  27 , there is a block that holds the outermost shim  13  in alignment with the sample section. Knob  19  is tightened to move the sliding block  12 . This tightens all of the shims  13  by pulling on barrel nut  16  in the sliding block  12  via rod  24 . Knob  19  can then be loosed slightly, allowing shims  13  to be moved until each shim  13  touches the sample section. Thus the shims  13  conform to the profile of the sample section. 
     Knob  19  can then be tightened to secure the shims  13 . As sliding block  12  tightens against the shims  13 , there may be some movement, or crush, of the shims  13 . This crush may change the profile set into the shims. To minimize this crush effect, locking thumb screw  18  may be used to secure the shims  13 . Preferably thumb screw  18  has a tip constructed from a material, such as TEFLON, that will not damage the shims  13 . By using thumb screw  18  to tighten the shims  13 , any crush in the shims  13  is taken up at the back end of the shims  13  and minimizes or eliminates any changes to the profile set into the shims  13 . 
     In various preferred embodiments, a magnet  17  can be used to help hold the shims  13  in place. Preferably, the magnet  17  is recessed into the rotating dovetail block  11 . 
     Once the profile is set and locked, the shim set up platform  27  is removed and the anti-tear-out fixture  22  is reinstalled. The anti-tear-out fixture  22  slides in an out on a guide pin  21 . Guide pin  21  helps keep the anti-tear-out fixture  22  aligned with the adjacent shim  13 . The anti-tear-out fixture is aligned such that the tip of the ramp  23  is aligned with the tip of the adjacent shim  13 . In use, guide pin  49  (shown in  FIG. 9 , and explained further below) will ride along the profile set into the shims  13 . When guide pin  49  rides up on the ramp  23 , the operator can feel and or hear the difference in the cutting operation and the operator can pull the router bit away from the fixture. The anti-tear-out fixture can be secured in place with knob  20 . 
     The molding to be coped can now be placed on top of the shims  13  and sliding block  12 . The molding to be coped is aligned with the shim  13  nearest the anti-tear-out fixture  22 , resting against the ant-tear out fixture  22 . For a right-hand cope, the molding is placed face up. For a left-hand cope, the molding is placed face down. 
     As most walls do not meet at exactly right angles, either intentionally or because of natural variation, it is desirable to be able to adjust the coping cut accordingly. Cradle support arms  14  hold the rotating dovetail block  11 . The rotating dovetail block is secured into the cradle support arms  14  with knobs  29 . When knobs  29  are loosened, the rotating dovetail block  11  can be rotated to the desired angle for the coping cut. Since everything above the cradle support arms  14  can be attached to the rotating dovetail block  11 , including the sliding block  12 , the shims  13 , the anti-tear-out fixture  22 , and the router guide platform  25 , these items rotate with the rotating dovetail block  11 . 
     Rotating the rotating dovetail block  11  causes the router to make an angle cut at the end of the molding to be coped. A degree marker  31  can be attached to the rotating dovetail block  11 . The degrees of rotation, left or right, can be marked on the cradle support arms  14 . The rotating dovetail block  11  can be locked at the desired angle by tightening knobs  29 . 
       FIG. 4A  shows a router guide platform as part of a coping fixture according to the present invention. Knob  26  is used to mount the router guide platform to the rotating dovetail block  11 . 
       FIGS. 5A-E  show an exploded view of a router mount plate as part of a coping fixture according to the present invention.  FIG. 6  shows an assembled view of a router mount plate as part of a coping fixture according to the present invention. The router mount plate  42  attaches to the router base plate  43 . The router mount plate  42  acts to hold guide pin  49  in alignment with the router bit. Use of guide pin  49  eliminates the need for a bearing to be attached to the router bit. Rod  36  secures the router mount plate  42  to the router base  43 . Rod alignment and securing nuts  37  are shown as being square and fitted into a slotted rectangular cut into the router mount plate  42 . When the rod alignment and securing nuts are secured with knobs  41 , the rod  39  secures the router mount plate  42  to the router base  43 . 
       FIG. 7  shows a bottom exploded view of a router mount plate as part of a coping fixture according to the present invention. The figure is an unassembled view of what is shown in  FIG. 8 , and includes a router mount plate adapted to hold a guide pin in alignment with a cutting bit.  FIG. 8  shows a bottom assembled view of a router mount plate as is shown unassembled in  FIG. 7  as part of a coping fixture according to the present invention. Horizontal pin adjustment mount  44  moves in and out for horizontal movement of guide pin  49 . The pin mount  45  allows for some lateral movement of guide pin  49 . Different sizes of guide pins  49  may be used with different sizes of router bits. Smaller router bits provide for greater detailing in the coping cuts. The pin horizontal adjustment mount  44  and pin mount  45  are secured by carriage bolts  52  and locked together with locking knobs  54 . 
     Guide pin  49  slides into pin bushing  53  and is held in place with pin hold 57. The pin hold 57 is secured by a small stud  47  and aligned by a small alignment pin  46 . Thumb nut  48  holds the pin hold 57 securely in place. 
       FIGS. 10A-C  show front, top and side views of a work piece platform of a coping fixture according to the present invention. The molding to be coped is held in place by being clamped to a work piece platform  33 . The work piece platform  33  can be secured, either bolted or clamped or the like, to a compound miter saw or other object as desired by the operator.  FIG. 9  shows a front view of a coping fixture according to the present invention. Alternatively, mount  15  may be connected to the side of a compound miter saw or the like. Mount  15  may be provided with T-slots for this purpose. If mount  15  is connected to a miter saw or other object, work piece platform  33  may be eliminated. 
       FIGS. 11A-D  show top and side views of a router stand for use in conjunction with a coping fixture according to the present invention. A router stand  56  can be used to help make the adjustments to the router mount plate  42  and guide pin  49 . For example, the router may be placed upside down (router base up) in the router stand  56  while the adjustments are being made. After the settings are complete, the router can rest, right side up, in the router stand  56 . 
     Special note may be made that the router mount  42 , having guide pin  49 , may also be used independently of the coping fixture as a scroll saw or similar cutting apparatus. Guide pin  49  is suitable for following any template. 
     In addition to coping moldings, the coping fixture described above may also be used to cope quarter round in much the same way. The settings of the shims  13  and the shim set-up platform  27  are accomplished in the same manner as described above. However, for quarter round, a hold down fixture  58  is needed.  FIGS. 12A-C  show top and side views of a quarter round holding fixture for use in conjunction with a coping fixture according to the present invention. A small sample of quarter round is used to set the profile of the quarter round into the shims  13 . This same sample piece of quarter round is then used as a spacer  59  in the quarter round holding fixture  58 . The other end of the quarter round holding fixture  58  has a block attached to it that pushed the work piece quarter round (the piece being coped) against the fence. A C-clamp can be used to hold the quarter round holding fixture  58  down so the coping cut may be made. 
       FIGS. 13A-C  show top, side, and front views of a height gauge for use in conjunction with a coping fixture according to the present invention. A height gauge  61  is used to set the height of the router bit when installed in the router. Since the coping fixture of the present invention incorporates a router guide platform  25  with a fixed height over the tool, the router bit will always extend a fixed amount. This fixed height remains the same, independent of what molding is being coped. Accordingly, since the height will remain the same, height gauge  61  may be used for quick and easy setup of the router bit height. A second function of the height gauge  61  is to align the guide pin  49  with the router bit. A groove cut into the height gauge  61  is pressed against the alignment pin  51 , which is temporarily installed in the router. When the guide pin  49  is aligned in the same groove, the guide pin  49  and the router bit are in alignment. 
     To set the vertical height of the guide pin  49 , two alignment markers  55  are used. One marker  55  is on the router mount  42 . The other marker  55  is on the horizontal mount  44 . When these two markers  55  point toward each other, the guide pin  49  is at the correct vertical height and will follow the sliding block  12  and the shims  13  as needed. 
     Friction tape can be used to help secure the various components together and help prevent them from slipping during operation of the coping fixture. For example, friction tape can be applied to the top of the router mount plate  42  to help secure the router base  43  in place. Friction tape may also be used on the pin horizontal mount  44  to help secure the pin mount  45  in place. 
       FIGS. 14A-D  show side and bottom views of a sliding block and sliding block rod of a coping fixture according to the present invention. Point A on the slide block  12  indicates the point of the sliding block  12  that supports the molding being coped. Adjustable holes are located in the bottom of the sliding block. A barrel nut  16  is attached to the sliding block rod  24 . The barrel nut  16  is offset from the rod  24 , the offset portion of the barrel nut  16  is inserted into one of the holes. The different holes permit the sliding block rod  24  to accommodate moldings of different sizes. 
       FIGS. 15A-B  show side and top views of a shim for use in a coping fixture according to the present invention. The shims  13  as shown are rectangular sections of material, preferably metal.  FIGS. 16A-B  show an extension block of a coping fixture according to the present invention. The extension block  62  can be used between shims  13  to fill places where curved profiles are not need in the molding to be coped. 
       FIGS. 17A-C  show an anti-tear-out ramp of a coping fixture according to the present invention. The anti-tear-out ramp  23  can be a replaceable portion of the anti-tear-out fixture  22 . Since the top portion of the anti-tear-out ramp is close to (and in some instances, may come into contact with) the router bit performing the coping cut, the top portion of the anti-tear-out ramp  23  may become worn over time. In various preferred embodiments, the anti-tear-out ramp  23  has two holes in it. One hole is for an alignment pin. The other hole can be used for a screw or other fastening device to secure the anti-tear-out ramp  23  to the anti-tear-out fixture. 
     While specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention and the scope of protection is limited by the scope of the accompanying claims.