Patent Application
20050204887
This invention relates to saws, and more particularly, to a cutting guide for effecting a straight and accurate cut along a workpiece.
Power saws, such as circular saws, jig saws, miter saws and other saws are used extensively for cutting wood and other types of materials. When doing so, the cutting operation should be performed as accurately and safely as possible. In many instances, the cutting operation is to be performed along one or more straight line segments on a workpiece and therefore, performing straight cuts is essential to high quality carpentry and construction.
Guides that cooperate with the saw so as to execute a straight cut along a workpiece are generally well known. The guide helps to reduce the inaccuracies or errors that would otherwise result if the saw inadvertently moved or bumped during the cutting operation. Power saws generally include a housing in which an electrical motor is mounted and the motor in turn is operatively connected to an arbor on which the saw blade is mounted. For many types of saws, the saw further includes a saw plate or shoe that provides an opening through which the saw blade projects. The saw plate also supports the saw when positioned on a workpiece. A side edge of the saw plate is generally parallel to the saw blade and at a predetermined, fixed distance from the saw blade. The side edge of the saw plate is often used as a bearing surface against an edge of the saw guide during the cutting operation. The contact between the side edge of the saw plate and the edge of the saw guide keeps the blade of the saw along a straight path.
When a workpiece, such as a plank, a trim member or a 2×4, must be cut to a particular length, the length of the piece to be cut is measured, and then cut. When measuring a workpiece, the position of the cut line is identified and marked, such as, for example, by using a T-square and a pencil to trace the straight cut line, by laying down a chalk line to mark the cut line or by other means known in the art. The cut line, however, identifies the path of the saw blade, thus when using a guide, one must compensate for the position of the saw blade relative to the position of the bearing edge of the saw guide. In other words, one must measure from the cut line to account for the spacing between the side edge of the saw plate which abuts the saw guide and the position of the blade.
The distance between the saw blade and the side edge of the saw plate, hereafter referred to as the offset, is generally not a standard width and typically depends on not only the type of saw one is using for the cutting operation but also on the make and model of that type of saw. Thus the offset must be measured for the particular saw being used to make the desired cut. A second mark is then made on the workpiece at a distance from the cut line that corresponds to the offset for the saw being used to make the cut. In this way, when the saw is placed on the workpiece and the side edge of the saw plate positioned against an edge of the saw guide, the saw blade should align with the desired cut line.
It is evident from the above description, however, that these calculations become quite tedious and prone to errors in the cutting process, especially when numerous pieces having generally the same dimension must be cut, particularly if a variety of different saws or models are used.
As such, a need exists for a cutting guide that reduces the potential for errors and inaccuracies when determining the position of the saw guide relative to the position of the cut line.
This invention provides a cutting guide that overcomes the above-mentioned and other problems by quickly and accurately locating the position of the saw guide relative to the cut line. The cutting guide includes a clamp, a saw guide pivotally coupled relative to the clamp and juxtaposed to a surface of the workpiece, a guiding edge on the saw guide providing a bearing support to a portion of the saw so as to guide the saw during the cutting of the workpiece, and a cutting template coupled to the clamp and juxtaposed to the surface of the workpiece. The cutting template is cuttable along a cut line so as to produce a template cutting edge. The template cutting edge identifies the position of the guiding edge relative to a cut line on the workpiece.
In one embodiment, the clamp includes a first clamping member fixedly secured to a lock bar extending from the first clamping member. A second clamping member is slidably coupled to the lock bar and is moveable so as to clamp varying sized workpieces therebetween. The second clamping member may be a quick release type with a handle having a first and second position. When the handle is in the first position the second clamping member is secured to the lock bar. When the handle is in the second position, the second clamping member is free to move along the lock bar. The saw guide is pivotally moveable between a plurality of positions. In one such position, the guiding edge of the saw guide is spaced from and generally parallel to the template cutting edge. To releasably secure the saw guide relative to the clamp, the saw guide includes a detent and the cutting template includes a plurality of recesses. The saw guide is so secured when the detent engages one of the recesses. The cutting template may be secured to the saw guide by a tongue and groove connection between the first clamping member and the template. In this way, a cutting template is quickly and easily removed or inserted into the cutting guide.
In use, a user must first cut an uncut cutting template to form the template cutting edge and its associated first template portion that is saw and angle specific. To do this, the guiding edge of the saw guide is aligned relative to the cut line on the workpiece so as to account for the saw offset. If the cut line is angled, then the saw guide must be pivotally moved to correspond to the desired cut line angle. The cutting guide is then releasably clamped to the workpiece. A portion of the saw is then abutted against the guiding edge of the saw guide and moved along the guiding edge during the cutting operation. During the cutting operation, the saw cuts through both the workpiece and the cutting template and thereby forms the template cutting edge and its associated first template portion that is saw and angle specific. A second portion of the cutting template is simply discarded.
The as-formed cutting template may then be used to cut subsequent workpieces using the same saw and at the same angle without measuring or accounting for the saw offset. To do this, the cutting edge of the template is aligned with the desired cut line on the workpiece. The cutting guide is then releasably clamped to the workpiece. A portion of the saw is then abutted against the guiding edge of the saw guide and moved along the guiding edge during the cutting operation. During the cutting operation, the saw cuts through only the workpiece along the desired cut line. A user could have a plurality of cutting templates, each template having a different first portion configuration corresponding to different saws and/or different angled cuts.
The features and objectives of this invention will become more readily apparent from the following Detailed Description taken in conjunction with the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.
In reference to
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In general, however, a quick release mechanism 38 includes a handle 40 moveable between a first and second position. When handle 40 is in the first position, second clamping member 30 is secured to lock bar 36. When handle 40 is in the second position, second clamping member 30 is moveable along lock bar 36 and may be positioned adjacent workpiece 22 so as to secure workpiece 22 between first and second clamping members 24, 30 when handle 40 is moved to the first position. In the trigger-type of locking mechanism 38 of
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With further reference to
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As shown in
So that the saw guide 14 does not move during a cutting operation, thereby affecting the accuracy of the cut, the position of the saw guide 14 relative to the cutting edge 10 is releasably fixed. As shown in
The cutting template 18 may be coupled to the cutting guide 10 in a number of ways known in the art. For instance, one way is to adhesively connect the cutting template 18 to first clamping member 24, as shown in
As shown in
The invention as described herein has a number of advantages. The primary advantage is that, after the cutting template 18 is cut to produce the template cutting edge 66 on first template portion 62, a user no longer has to know or mark the position of the guiding edge 16 of the saw guide 14, but must only know the position of the cut line 20, which is the normal course of cutting operations. Removing this step greatly reduces the errors and mistakes made when compensating for the offset in the saw being used to make the cut. This also reduces the time to make the cuts on a workpiece, especially when there are numerous workpieces having the same type of cut configuration. Another advantage of the present invention is that because the cutting guide 10 is clamped onto the workpiece, the user may use two hands when operating the saw 19. This then allows a user to make a safer cut without sacrificing cutting accuracy. The safety of cutting operations is also improved by providing a rigid platform from which to start the cutting operation. In many instances, carpenters and other users do not have a platform or starting surface for which to operate the saw, such as a circular saw, before engaging the workpiece. In this invention, the cutting template 18 is sized to provide a platform for operating the saw prior to engaging the workpiece. This makes the entry into the workpiece cleaner and reduces the likelihood of the workpiece “kicking” or presenting other safety hazards.
The cutting guide 10 may also include other features frequently used in woodworking and construction applications. For instance, the saw guide may include a level indicator 88 for gaging the orientation of the saw guide. Moreover, the saw guide and first clamping member may be configured to be in perpendicular relation to each other. When so configured, the cutting guide may also be used as a T-square. The saw guide and/or first clamping member may then include ruler markings or indicia of length typically found on a carpenter's square.
While this invention has been illustrated by the description of the various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. For instance, those of ordinary skill in the art will recognize that the cutting template does not have to be removable from the cutting guide but a user may have a different cutting guide for the user's various saws and cut configurations. If this be the case then it should be recognized that the saw guide does not have to move relative to the cutting template and may in fact be integrally formed with the cutting template. Alternately, the integrally formed saw guide and cutting template may be the quick attachment type and a user have a plurality of these saw guide/cutting template inserts having different combinations for the user's various saws. Furthermore, it should be understood that while the illustrated embodiments show a cutting guide directed towards cutting operations from left to right when the saw guide is angled, the cutting guide may also be configured to make cuts from right to left when the saw guide is angled.
Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.
