Abstract:
A new clamp for woodworking. The clamp features two parallel clamp rails joined at each end by connecting members. The movement of sliding clamps along the clamp rails is coordinated by a bracing member which connects the sliding clamps together and provides a clamping surface.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to the field of wood-working. More specifically, the invention comprises a woodworking framework clamp which can be used to fabricate drawers and the like.  
         [0003]     2. Description of the Related Art  
         [0004]     Clamps are widely used in the fabrication of drawers and in many other woodworking applications. It is often necessary in these applications to hold four members together as a frame as they are fastened together by wood glue, nails, screws, staples, disks, or dowels. This is often accomplished by using a single clamp or combination of clamps to provide force to the assembled frame from four different directions.  
         [0005]     Numerous clamps are used in the prior art to supply force to the sides of a drawer as the members are fastened together. Examples of prior art clamps include those described in U.S. Pat. Nos. 2,619,136; 4,132,396; 2,753,902; and 4,027,866. Although these clamps function to hold a drawer frame together as the members are fastened together, they are cumbersome or inefficient in practice. Many prior art clamps come in multiple pieces which can become separated or lost. Other prior art clamps provide long threaded screws and wing nuts as a means of tightening the clamp around the frame. These threaded-screw clamps often require the user to turn multiple wing nuts for many revolutions until the corner brackets of the clamp can engage the members of the frame. Even more, many of these clamps are ineffective in ensuring a square relationship between the members of the frame when the drawer is clamped therebetween.  
         [0006]     It is therefore the purpose of the present invention to provide a woodworking clamp that overcomes the problems with the prior art clamps and is efficient and easy to use.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     The present invention comprises a woodworking clamp that can be used for the fabrication of drawers and the like. The clamp features two parallel clamp rails joined at each end by connecting members. A preferred embodiment of the present invention includes a sliding clamp attached to each rail. The sliding clamps operate in unison, and their movement along to the clamp rail is coordinated by a bracing member which adjoins the two clamps. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0008]      FIG. 1  is a perspective view, showing the preferred embodiment of the present invention  
         [0009]      FIG. 2  is a perspective view, showing the preferred embodiment of the present invention clamped around a drawer.  
         [0010]      FIG. 3  is a perspective view, showing the clamp mechanism.  
         [0011]      FIG. 4  is a top view, showing the clamp bracket.  
         [0012]      FIG. 5  is a perspective view, showing an alternate clamping mechanism.  
         [0013]      FIG. 6  is a perspective view, showing an alternate clamping mechanism.  
         [0014]      FIG. 7  is a perspective view, showing an alternate clamping mechanism.  
         [0015]      FIG. 8A  is a perspective view, showing an alternate embodiment of the clamp rail.  
         [0016]      FIG. 8B  is a perspective view, showing an alternate embodiment of the clamp rail.  
         [0017]      FIG. 9  is a perspective view, showing an alternate embodiment of the present invention.  
         [0018]      FIG. 10  is a perspective view, showing an alternate embodiment of the present invention. 
     
    
     REFERENCE NUMERALS IN THE DRAWINGS  
       [0019]      10  drawer clamp  
         [0020]      12  clamp rail  
         [0021]      14  connecting member  
         [0022]      16  sliding clamp  
         [0023]      18  bracing member  
         [0024]      20  face plate  
         [0025]      22  connecting bracket  
         [0026]      24  drawer  
         [0027]      26  drawer frame  
         [0028]      28  drawer base  
         [0029]      30  handle  
         [0030]      32  threaded shank  
         [0031]      34  clamp bracket  
         [0032]      36  bracing bracket  
         [0033]      38  non-threaded shank  
         [0034]      40  orifice  
         [0035]      42  orifice  
         [0036]      44  joint  
         [0037]      46  threaded orifice  
         [0038]      48  rail orifice  
         [0039]      50  notches  
         [0040]      52  ridges  
         [0041]      54  gripping bracket  
         [0042]      56  handle  
         [0043]      58  ratcheting lever  
         [0044]      60  spring toggle  
         [0045]      62  screw tightener  
       DESCRIPTION OF THE INVENTION  
       [0046]     A detailed illustration of the preferred embodiment of the present invention is shown in  FIG. 1 . Drawer clamp  10  is provided with two clamp rails  12 . Clamp rail  12  is illustrated in  FIG. 1  as a cylindrical metal rod with a circular cross section. Clamp rail  12 , however, can be made of other materials such as wood or plastic, and can have non-circular cross sections including rectangular, elliptical, and I-shaped cross sections. Connecting members  14  maintain clamp rails  12  in parallel position and attach to the rails at each end. Connecting members  14  are metal rods with circular cross sections in  FIG. 1 , but other materials and cross sections can also be used.  
         [0047]     Connecting brackets  22  are used in the preferred embodiment to connect the ends of connecting members  14  to the ends of clamp rails  12 . Connecting members  22  help maintain a perpendicular relationship between connecting members  14  and clamp rails  12 , thereby ensuring that clamp rails  12  remain parallel.  
         [0048]     A sliding clamp  16  is connected to each clamp rail  12 . Bracing member  18  is connected to both sliding clamps  16 , thereby coordinating the movement of the clamps along clamp rails  12 . Bracing member  18  also functions as a clamping surface used to supply force to objects being fastened together as later illustrated and described. In the preferred embodiment face plate  20  is attached to connecting member  14  in a direction parallel to and facing bracing member  18 . Face plate  20  also functions as a clamping surface.  
         [0049]      FIG. 2  illustrates how the present invention is used to clamp a drawer during fabrication. Drawer clamp  10  operates to supply clamping force to drawer frame  26  as the pieces are fastened together. Drawer  24  is assembled between bracing member  18  and face plate  20 . Drawers are commonly assembled by adjoining four frame members together forming drawer frame  26  and drawer base  28 .  
         [0050]     Many methods can be used to fasten the members of the frame together. One common method of fabrication involves the use of wood glue or a combination of wood glue and dowels or discs as a fastening means. If wood glue is used, the user can dispense wood glue along joints  44  in drawer frame  26 . The glued drawer can be placed between face plate  20  and bracing member  18 . Bracing member  18  can be slid down clamp rail  12  by sliding the clamps until contact is made with drawer frame  26 . Since wood glue creates its tightest bond when it dries under compression, sliding clamps  16  can then be used to tighten bracing member  18  and front plate  20  around the assembly so as to supply compressive force to the frame members. Force is supplied to the drawer by the clamp using a levered-clamping means which is described later. The drawer is then retained in the clamp until the glue dries.  
         [0051]     Other methods of fabrication involve the use of other means of attachment such as screws, nails, and staples. The drawer clamp can be used in these methods to provide a means of alignment of the drawer frame as the frame members are attached together. The user can assemble the frame between bracing member  18  and face plate  20 , and then bring bracing member  18  into contact with drawer frame  26 . The frame members can then be adjusted into alignment and sliding clamps  16  can be used to provide clamping force to drawer frame  26  as the frame is nailed, screwed, or stapled together.  
         [0052]     A detailed view of a preferred embodiment of the sliding clamp mechanism is shown in  FIG. 3 . Bracing bracket  36  is attached to bracing member  18 . Bracing bracket  36  has orifice  40  which is sized to receive non-threaded shank  38  of sliding clamp  16 . Threaded shank  32  is fed through threaded orifice  46  of clamp bracket  34 . Clamp bracket  34  has rail orifice  48  through which clamp rail  12  passes, thereby facilitating slidable engagement of clamp bracket  34  with clamp rail  12 .  FIG. 4  shows a top view of clamp bracket  34  with rail orifice  48  and threaded orifice  46  for clearer illustration.  
         [0053]     With reference to  FIG. 3 , the clamp is tightened by turning handle  30 . Those skilled in the art will understand that rotation of handle  30  of sliding clamp  16  will increase the distance between clamp bracket  34  and bracing member  18 . Clamp bracket  34  operates as a lever when handle  30  is turned and creates a pinch-point between rail orifice  48  and clamp rail  12  as bracing member  18  is compressed against the drawer. This lever action prevents the translational movement of clamp bracket  34  vis-à-vis clamp rail  12 .  
         [0054]     Other sliding clamp mechanisms can be used to accomplish a similar levered-clamping action.  FIG. 5  shows a modified sliding clamp. Sliding clamp  16  features spring toggle  60  and ratcheting lever  58  for improved gripping of clamp rail  12  by sliding clamp  16 . The user operates the clamp by squeezing spring toggle  60  towards handle  56  and sliding sliding clamp  16  down clamp rail  12  until bracing member  18  comes in contact with the object to be clamped. Spring toggle  60  has an orifice (not shown) through which clamp rail  12  passes such that sliding clamp  16  can slide freely along clamp rail  12  when spring toggle  60  is depressed but will not slide when spring toggle  60  is released because of friction between spring toggle  60  and clamp rail  12 . The user can then squeeze ratcheting lever  58  towards handle  56 , thereby tightening the clamp around the object to be clamped.  
         [0055]      FIG. 6  shows the sliding clamp of  FIG. 3  featuring a spring toggle. Spring toggle  60  can be added to any sliding clamp to improve the grip of clamp bracket  34  with respect to clamp rail  12 . The spring toggle of the embodiment shown in  FIG. 5  operates the same as spring toggle  60  in  FIG. 4 .  
         [0056]      FIG. 7  shows the sliding clamp of  FIG. 3  featuring a screw tightener. Like spring toggle  60 , screw tightener  62  can be added to any sliding clamp to improve the grip of clamp bracket  34  with respect to clamp rail  12 . When screw tightener  62  is rotated, screw tightener  62  bears against clamp rail  12 , thereby increasing the frictional force between clamp rail  12  and clamp bracket  34  and screw tightener  62  and preventing the translational movement of clamp bracket  34  vis-à-vis clamp rail  12 .  
         [0057]     In addition, clamp rails  12  can be altered to improve the levered-clamping action. Alternate embodiments of the clamp rail are shown in  FIGS. 8A and 8B .  FIG. 8A  shows clamp rail  12  enhanced with notches  50 . This treatment to the surface of clamp rail  12  can improve its “gripability” by providing a surface that is closer to perpendicular with respect to rail orifice  48  when the levered-clamping action causes rail orifice  48  to mate with clamp rail  12 . A similar effect can be created by enhancing the surface of clamp rail  12  with ridges  52  as illustrated in  FIG. 8B .  
         [0058]     An alternate embodiment of the invention is shown in  FIG. 9 . The alternate embodiment features only one sliding clamp  16  instead of two. In the place of the second sliding clamp, elongated bracing member  18  with orifice  42  is provided to engage clamp rail  12 . Similarly, as illustrated in  FIG. 10 , gripping bracket  54  with orifice  42  can also be used in place of the second sliding clamp to engage clamp rail  12 . In both of these embodiments clamping force is provided by turning single sliding clamp  16 .  
         [0059]     Although the preceding description contains significant detail, it should not be construed as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. As an example, drawer clamp  10  is not solely for the fabrication of drawers and wordworking but can instead be used for any application where such a clamp is needed.