Abstract:
A guide for a tool such as a router includes a support structure attachable to a table and having a mounting surface. A fence portion such as a rectangular fence block is coupled to said mounting surface for guiding a workpiece to and from the tool. An adjustment structure is included for positioning the fence portion at one of a plurality of predetermined distances from the mounting surface. At least one coupling couples the fence part to the mounting surface, and holds the fence portion at the predetermined distance from the mounting surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a guide for a tool, and more particularly relates to a guide fence for a router and other similar tools. 
     2. Description of the Related Art 
     Guide fences are used with tools such as routers and saws to guide a workpiece such as a block of wood while the workpiece is cut or otherwise worked by the tool. Typically such fences are divided into separate portions, including an in-feed fence portion and an out-feed fence portion. A tool is generally placed between the two fence portions. Work is performed on the workpiece such as trimming the workpiece by removing a surface layer. During this operation, the workpiece may move back and forth, or seesaw, as the workpiece is trimmed or cut due to the unevenness in shape between the portion of the workpiece that has already been trimmed, and the untrimmed portion. As a result, the workpiece can be pulled further into the tool, resulting in inaccurate cutting, and possible damage to the workpiece. 
     It is known to alter the placement of out-feed fence portions, in order to prevent this seesawing action. For example, U.S. Pat. No. 1,664,969 to Conover describes a guide fence having a wedge shape that may be moved along an angled plate using an adjusting screw located at the blunt end of the wedge in order to push the forward surface of the guide fence outwardly. U.S. Pat. No. 1,947,885 to Tautz discloses an adjustable guide fence having an adjusting screw which operates to laterally move a generally rectangular guide fence. Similar concepts are described in U.S. Pat. No. 2,104,158 to Hedgpeth, U.S. Pat. No. 4,719,951 to Woltanski, U.S. Pat. No. 4,787,614 to Givens, and U.S. Pat. No. 5,908,061 to Blichmann. 
     Known adjustable guide fences require careful measurement of the amount of the workpiece to be worked and careful consideration of the required position of the guide fence. Satisfying these requirements can be time consuming, and the chances of making an error in positioning can be great. For example, if the guide fence is set too far forward, it can obstruct the movement of the workpiece, whereas if it is set too far back, the problem of seesawing of the workpiece returns. Often, a user must perform an iterative series of adjustments using a test workpiece in order to insure that the guide fence is correctly positioned. 
     In addition, known adjustable guide fences are only held in position by the adjusting screw that is used to adjust the positioning of the fence. Over time, vibration and wear to the adjusting screw can cause the screw to loosen slightly, causing movement of the guide fence in use. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention relates to a guide for a tool. The guide includes a support structure having at least one mounting surface. A fence portion is coupled to the mounting surface. An adjustment structure for positioning the fence portion at one of a plurality of predetermined distances from the mounting surface is also included. At least one coupling is included for coupling the fence portion to the mounting surface and for holding the fence portion at the predetermined distance from the mounting surface. 
     The adjustment structure and coupling enable the fence portion to be incrementally moved to a predetermined distance from the mounting surface, and to be firmly held in position. The guide can thus be easily set, and is reliable in use. 
     Another aspect of the invention relates to a guide for a tool including a support structure having at least one mounting surface. An in-feed fence portion is coupled to the mounting surface for guiding a workpiece to the tool. An out-feed fence portion is coupled to the mounting surface for guiding the workpiece from the tool. Also included is an adjustment structure for positioning the out-feed fence portion at one of a plurality of predetermined distances from the mounting surface. A coupling structure is included for coupling the fence portions to the mounting surface and for holding the out-feed fence portion at the predetermined distance from the mounting surface. 
     A further aspect of the invention relates to a work table for a tool, the work table having a guide fence including a support structure attached to the work table and having a mounting surface. An in-feed fence portion is coupled to said mounting surface for guiding a workpiece to the tool. An out-feed fence portion is coupled to the mounting surface for guiding a workpiece from the tool. An adjustment structure is included for positioning the out-feed fence portion at one of a plurality of predetermined distances from the mounting surface. Coupling structures are provided for coupling the fence portions to the mounting surface and for holding the out-feed fence portion at the predetermined distance from the mounting surface. 
     Another aspect of the invention relates to an adjustment structure for a guide for a tool, the guide having a mounting surface and a fence portion. The adjustment structure includes an adjustment block for insertion between the mounting surface and the fence portion. The adjustment block has adjustment structure for positioning the fence portion at one of a plurality of predetermined distances from the mounting surface. 
     Yet a further aspect of the invention relates to a method of guiding a workpiece from a tool, including providing a support structure and having a mounting surface. A fence portion is coupled to the mounting surface for guiding a workpiece from the tool. An adjustment structure is set in order to position the fence portion at one of a plurality of predetermined distances from the remounting surface. The fence portion is held at the predetermined distance from the mounting surface. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There are shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentality shown, wherein: 
     FIG. 1 is a rear perspective view of a guide according to the present invention; 
     FIG. 2 is a perspective view of a guide according to the present invention; 
     FIG. 3 is a partial exploded front perspective view of the guide of FIG. 1; 
     FIG. 4 a  is an end view of part of a guide according to the present invention in a first position; 
     FIG. 4 b  is an end view of the part of the guide shown of FIG. 4 a  in a second position; and 
     FIG. 5 is a view of a guide according to the present invention with a tool. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A guide  10  for a tool according to the invention is shown in FIGS. 1 and 2. The guide has a supporting structure  12 . The supporting structure can be any suitable shape. In one arrangement, the supporting structure is L-shaped and includes a first mounting surface  14  and a second mounting surface  16 . The first and second mounting surfaces  14 ,  16  are substantially perpendicular. The first mounting surface  14  can be arranged in any suitable manner, such as horizontally, and can be coupled to a work table by any suitable fastener  18 , such as, for example, by means of bolts and nuts. The guide  10  can also include one or more fence blocks  20 . The fence blocks  20  can be coupled to the second mounting surface  16  of the supporting structure  12  and can have a rectangular shape. The second mounting surface  16  may be arranged vertically. It should be appreciated that the supporting structure need not be L-shaped and that the fence blocks need not be of a rectangular shape, as any suitable shapes may be used. In addition, the supporting structure may be provided integrally with a work table, rather than separately as in the illustrated embodiment. In one embodiment, the supporting structure  12  may be formed of metal, for example cast aluminum, and the fence blocks  20  may be formed of any suitable material, such as, for example, wood, particle board, or medium density fiberboard. In one arrangement, the guide can contain two fence blocks  20 , one of which can be an in-feed fence block  20   a  and the other of which can be out-feed fence block  20   b.  The fence blocks may be coupled to the second mounting surface  16  in any suitable manner, such as by fasteners  22  and fasteners  24 . In the illustrated arrangement, two fasteners  22  are used for each fence block  20 , the fasteners  22  passing through two apertures  26  in the second mounting surface  16  and two elongated apertures  28  in the fence blocks  20 , but the invention is not limited in this regard. The elongated apertures  28  in the fence blocks  20  are countersunk so that heads of fasteners  22  sit flush with the surface of the fence blocks, in order not to damage or obstruct workpieces that are pressed against the fence blocks. The fence blocks  20  may have chamfered inner ends  30  to allow for positioning of a tool between the two fence blocks  20 . A spacer plate  32  may be located between the vertical mounting surface  16  and the in-feed fence block  20   a  so that the position of the in-feed fence block  20   a  may be set. 
     A stair step structure  34  can be positioned between the second mounting surface  16  and the out-feed fence block  20   b  for adjusting the position of the out-feed fence block  20   b,  as shown in FIG.  3 . The stair step structure  34  can include a rigid adjustment block  36  placed between the fence block  20   b  and the second mounting surface  16 . The adjustment block  36  may be of any suitable shape, such as rectangular, and may be formed of metal, for example cast aluminum, or any other suitable material. The stair step structure may also include notches  38  cut into the part of the surface of the second mounting surface  16  that is coupled to the out-feed fence block  20   b.  In the illustrated embodiment, two sets of notches  38  are employed. However, one set or more than two sets of notches per stair step structure may be used. Each notch  38  can have a different pre-determined depth, and the notches can be positioned in ascending or descending order. Thus, for example, if the notches were positioned in ascending order, the first notch  38   a  can be the deepest notch and each successive notch  38   b - 38   d  can be slightly shallower than the preceding notch by a predetermined distance. As such, both sets of notches  38  can have an appearance similar to that of a set of steps. In one arrangement, each notch  38  can increase in height by roughly {fraction (1/32)} of an inch, as trimming distances are commonly incremented by this particular measurement when blocks of wood are trimmed with certain tools, such as, for example, a router. Different heights of notches can be employed in different embodiments of the invention. For example, the notches may differ in height by 1 mm for use with metric tools, such as routers or cutters. For larger tools, the notches may differ by larger amounts, such as, for example {fraction (1/16)} of an inch. The depth of the deepest notch  38   a  and the depth of the body of the adjustment block  36  may be set so that the out-feed fence block is positioned at the same distance from the second mounting surface as the in-feed fence block. For example, the depths of the spacer plate  32  for in-feed fence block  20   a  and the adjustment block  36  for out-feed fence block  20   b  may be the same. Alternatively, the dimensions of the components may be set so that the depth of the deepest notch  38   a  and adjustment block  36  causes the out-feed fence block to be positioned one incremental distance, for example, {fraction (1/32)} of an inch, further forward than the in-feed fence block  20   a,  or at any other distance. The illustrated embodiment includes four notches  38  of varying height, but any number of notches may be used, depending on the intended purpose of the stair step structure. 
     The adjustment block  36  can also include several notch engaging fins  40 , which may be arranged vertically. In one embodiment, the adjustment block  36  has two such vertical notch engaging fins  40  a fixed distance apart in which one fin is attached to one end of the adjustment block, and the other fin is attached to a second end opposite that of the first end. The notch engaging fins  40  can engage a set of notches  38  in the second mounting surface  16 . The notch engaging fins  40  can engage corresponding notches  38  of an equivalent height. It should be appreciated, however, that any number of notch sets and notch engaging fins may be provided. 
     The adjustment block  36  can also include a gripping segment  42 . The gripping segment  42  can be on any suitable portion of the adjustment block  36 , including the top of the adjustment block  36 . The gripping segment  42  can permit a user to slide or otherwise move the adjustment block  36  along the length of the mounting surface  16  that is coupled to the out-feed fence block  20   b,  thereby enabling the notch engaging fins to engage one or more of the notches  38 . The adjustment block  36  may also have elongated apertures  44  to receive fasteners  22 . 
     It will be appreciated by persons skilled in the art that the notches  38  may be cut in the adjustment block  36  instead of in the mounting surface  16  as illustrated, and that the mounting surface  16  may be provided with notch engaging fins or other suitable means for engaging the notches. 
     A cut-out area  46  may be located in the second mounting surface  16 , for positioning of the tool. The cut-out area  46  may be closed for storage and transport purposes by a plate  48 , which may be of plastic or any other suitable material. The plate  48  can be secured to the second mounting surface  16  by fasteners  50 . A threaded aperture  52  may be located in the top of the support structure  12  for securement of a tool. It will be appreciated that it is not necessary to provide both the in-feed and the out-feed fence blocks attached to one mounting surface. Separate mounting surfaces could be provided, for example. Alternatively, the in-feed fence may be an integral part of a work table. For some uses, only an adjustable out-feed fence block may be provided, while for other uses only an adjustable in-feed fence block may be provided. In an alternative arrangement, both an adjustable in-feed fence block and an adjustable out-feed fence block may be used. 
     According to one embodiment of the invention, and referring to FIG. 5, in operation the user can remove plate  48  from cut-out area  46  of the guide  10  and can secure the guide fence  10  to a work table  54  using fasteners  18 . The cut-out area  46  can be located around a tool  56 , for example, a router. Alternatively, as shown in FIG. 5, a tool  56  may be secured underneath the table  54  so that a cutting head  58 , such as a router bit, can project through an aperture  60  in the table  54 . The table  54  may have one or more workpiece guides  62 , a power supply  64 , and any other suitable accessories. It will be appreciated that the illustrated work table  54  and tool  56  are exemplary only, and that guide  10  may be used with any type of surface on which working of a workpiece is to take place, and that a tool may be used in many different configurations with the guide  10 . 
     The user determines the amount of material to be removed by the tool  56 , and sets the tool  56  accordingly. Once this distance is determined, the user can set the adjustment block  36  of the stair step structure to correspond to this particular distance. As an example, and referring to FIGS. 4 a  and  4   b,  if the block of material is to be trimmed by {fraction (1/16)} of an inch, and the depth of each notch  38  varies by {fraction (1/32)} of an inch, then the user can grasp the gripping segment  42  and slide the adjustment block  36  from the furthest back position with the notch engaging fins  40  engaging notches  38   a  until the notch engaging fins  40  engage the appropriate notches  38   c.  Once so positioned, the out-feed fence block  20   b  can extend outwardly away from the second mounting surface  16  approximately {fraction (1/16)} of an inch farther than the in-feed fence block  20   a.  The user can then tighten fasteners  24  to firmly hold the out-feed fence block  20   b  in position, and can position the block of material to be trimmed against the in-feed fence block  20   a.  The section of material can then be fed along the in-feed fence block  20   a  towards the stationary router or other tool  56 , where it can be trimmed, and then continues to the out-feed fence block  20   b.    
     As the router or other tool trims the section of material, the portion of the block of material not yet trimmed is actually {fraction (1/16)} of an inch wider than the portion of the material already trimmed. Significantly, however, once the trimmed portion of the block of material reaches the out-feed fence block  20   b  of the present router fence  10 , the block of material will not seesaw. The seesaw effect is curtailed because the trimmed portion of the block of material will be pressed up against the out-feed fence block  20   b  when it reaches the out-feed fence block  20   b,  as the outwardly adjusted (by {fraction (1/16)} of an inch) out-feed fence block  20   b  compensates for the loss of the portion of the material block removed by the router. 
     It will be understood that the user does not have to carefully measure the differences in the positions of the in-feed and out-feed fence blocks, but can simply choose the notch that corresponds to the desired trimming distance. The trimming distance may be marked on the top of the vertical mounting surface, or may be included in any suitable place. This enables a user is able to set the guide fence to the correct position quickly and easily. 
     The present invention has been described with the use of an adjustment block and stair step structure for performing the incremental movement of the out-feed fence block. However, any suitable means of performing an incremental adjustment in distance may be employed. A stair step structure may be located between the fence block and the mounting surface without the need for an intervening adjustment block. For example, the notch engaging fins may be provided directly on the fence block. It is also not necessary to include a stair step structure, as incremental movement of the position of the fence block may be achieved using the movement of a pin along a notched groove, a stepped cam, a ratchet and pawl mechanism, or with any other suitable mechanism. In another embodiment, grooves or notches for receiving and setting the position of the fence block may be located in a horizontal mounting surface underneath the fence block, rather than the vertical mounting surface. 
     The illustrated embodiment is described in use with a power tool such as a router. However, it will be appreciated that the invention is useful in acting as a guide for many different types of tools. As examples, the invention is useful for guiding a workpiece to a hand tool, and may be used with a sander, circular saw, miter saw, spindle shaper, any other table-mounted tool, and any other suitable tool. 
     It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application. The invention can take other specific forms without departing from the spirit or essential attributes thereof.