1. Field of the Invention
This invention relates to craftsman's tools and more particularly to tools designed to produce a straight, smooth edge on a piece of lumber or other material which may have a "crook" or flat bow or rough mill edges.
2. Description of the Prior Art
In working with sheets or boards of raw material, such as wood, plywood, or masonite, there is always an interest in minimizing costs to maximize profits and reduce waste. For instance, in woodworking, one can save substantial amounts of money by purchasing unfinished, rough mill lumber. Sometimes, the desired lumber is only available in unfinished form. Regardless, the raw material needs at least one straight, smooth edge as a reference edge for future shaping and cutting.
Prior art discloses devices or tools developed to take advantage of the lower prices for rough cut lumber, while seeking ways to guarantee straight edges on lumber and other building materials to be used as furniture, cabinets, counter tops, wall boards, paneling, and for many other purposes including, but not limited to, general construction purposes.
In general, these prior art devices include independent clamps of various designs and flat bars which use clamps or screws for attachment to the lumber or other material to be cut.
A typical prior art device comprises two clamps. One end of each clamp is tightened around one edge of a known straight board; the other end is tightened to the bowed board. The unobstructed end of the straight board is then used as the contact surface to a saw fence or guide to make a straight cut along the bowed board. This method requires a constant examination of the straight board to determine any warpness or damage from use and a constant checking of the integrity and tightness of the clamps used to prevent relative movement between the straight and bowed lumber prior to and while sawing.
Other prior art devices include cutting guides usually made of aluminum. Some of these are of fixed length while others can be lengthened for cutting longer pieces of wood, wallboard, masonite, and paneling. These devices attach by clamps to the board being cut. These clamps may be the well-known "C" clamps (screw type). In use, a plurality of "C" clamps are placed around both the guide and the board, and holds them together by frictional forces created by compression across the thickness of the guide and the board.
Alternatively, jaw-type clamps may be used. A plurality of these clamps are typically rigidly attached to the underside of the guide. The jaws then are positioned around the board to be cut across its thickness and are clamped shut by pressing a lever. As with the "C" clamps, the board is held relative to the guide by frictional forces created by compression across the thickness of the board.
All of these prior art devices are very difficult to use with a saw fence due to the interferences caused by clamps protruding to the side or below the surface of the board to be cut. Furthermore, under the intense vibrational forces occurring during sawing often loosen the compression-type hold on the board, resulting in board movement and a non-straight cut along the board.
Thus, there remains a significant need for a tool or saw guide designed to eliminate the flat bow out of rough cut mill lumber of varying lengths or other materials and provide a near perfect saw cut edge while also allowing the use of a standard table saw, radial saw, or circular saw.