The disclosed embodiment is directed generally to woodworking and more specifically to wooden corner joints and the tooling which is suitable to create wooden corner joints.
In the construction of wood frames for applications such as doors, picture frames, cabinetry, etc., rail and stile members may be used to form a wooden corner joint. The “rail” member runs horizontally and the “stile” member runs vertically, at least according to the generally accepted conventions and definitions. Typically, one member is milled or machined with one or more projections (tenons) and recesses (mortises) and the other member is milled or machined with matching tenons and mortises, only in reverse. Further, these two members are milled or machined so that the joint (the tenon of the rail into the moritise of the stile and the tenon of the stile into the mortise of the rail) defines a right angled corner joint for the article being fabricated.
While different methods or techniques can be used for the machining or milling of the desired shapes into the rail and stile, one popular approach is to use a shaper cutter. Typically these woodworking machines have relatively large (over 3 inches in diameter) individual cutters which are received by a spindle. When used for rail and stile joints, there are typically three cutters and the individual cutters are able to overlap due to their mounting on the spindle. This arrangement and the ability to overlap enables the stile edges to be radiused
Another option for milling (i.e., woodworking) a rail and stile joint is to use a router. The router receives a first router bit which is configured for the desired rail shapes (tenons and mortises) and the first portion of the corner joint is milled using the router and the selected router bit. Next, this first router bit is removed from the router and a second (matching) router bit is loaded into the router for the desired stile shapes. Since a tight and precise fit is important, these two router bits (rail and stile) are typically sold as a matched set. This means that whatever geometry might be selected, the two router bits create the tenons and mortises for that geometry where one is the reverse of the other. The orientation of each workpiece for each router bit cut (or cuts) is what determines that the joint will be a right angled corner joint. Some of the more common (matched) rail and stile geometries include ogee, shaker, round over, traditional, classical, bead and bevel. However, there are no actual restrictions on the geometry which one may select so long as the rail and stile router bits for that particular geometry are provided as a matched set so that one is the reverse of the other.
In terms of differences between using shaper cutters for a rail and stile versus using a matched router bit set, one difference is that the router bits are fixed on a shaft without the ability to overlap. Although multiple components are used in creating the stile bit, these components are secured together and fixed onto the shaft so as to create an integral unit (i.e., the stile bit). The same is true for the rail bit, although most of the components are different from those used in the stile bit.
As for the setup, the router is typically positioned beneath the worktable with the router bit extending upwardly, as shown by
One of the requirements for the resultant wooden corner joint is that the rail and stile fit be somewhat tight and precise. Dimensions, tolerances, shapes, etc. are generally held to fairly exacting standards. As a part of these more precise shapes and exacting standards, the tenons and mortises typically have relatively sharp corners whether speaking of interior corner recesses or speaking of exterior corner edges.
One of the accepted limitations of router bit configurations for a rail and stile joint is that radiused edges on the stile are not considered to be possible or at least practical in view of the complexities and milling difficulties for the required router bit configurations.
This limitation, or at least the industry perception of this limitation, is based in part on the fact that the router bits are smaller (as compared to shaper cutters) and based in part on the fact that the bottom cutter is always attached to the shaft. As noted, the ability of the cutters to overlap is not possible with the router bits as it is with the shaper cutters.
In the milling of the rail and stile workpieces, including the resultant sharp corners (recesses and edges), all of which follows the traditional wisdom, it has been found that the wood stock being used for the desired corner joint will exhibit some chipping and splintering. If by chance this occurs in an area or region which is not visible once the joint is made, there may be fewer concerns. However, in all likelihood any chipping or splintering will be visible along the exposed edge of the stile which lays up against the interior panel of the article. Further, the joint is not considered to be as secure if there is any noticeable chipping and/or splintering of the wood stock.
The industry perception of router bit designs, and their design limitations, for a rail and stile joint is that creating radiused edges (and matching mortises) is not really a viable option. However, due to the continuing chipping and splintering issues, the radiused edge objective was the subject of additional design studies and trials resulting in the disclosed embodiment. As disclosed herein, a matched rail and stile router bit set is provided which creates a suitable edge radius as a way to try and minimize, or at least significantly reduce, any edge chipping and/or splintering problems.
A matched rail and stile router bit set is constructed and arranged with cutting edge geometries which create radiused edges for the stile workpiece and at least one corresponding radiused recess in the rail workpiece.
One object of the present disclosure is to describe an improved matched rail and stile router bit set.
For the purposes of promoting an understanding of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated device and its use, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.
Referring first to
As mentioned above, conventional practice in terms of router bit design creates the rail and stile bits such that each interior corner recess is a relatively sharp corner approximating ninety degrees (90°) and each exterior corner edge is a relatively sharp corner approximating ninety degrees. The conventional practice in the design of the required router bits was to accept those bits which, by their configuration, would result in these relatively sharp corners and edges. The result though is that creating these sharp corners and edges causes chipping and/or splintering of the workpiece. Even though this problem existed, the difficulties in understanding how and where to modify the required router bits so as to avoid or reduce these sharp corners was not something known or practiced in terms of router bit designs. Further, there might have been a certain tolerance to accept some degree of chipping and/or splintering if it would occur in an area which might not be as visible in the final corner joint. However, even under those circumstances, chipping and/or splintering is still not desired.
Referring now to
More specifically, the radiused inside corner 44a of the rail 40 is milled (via a router) by the use of router bit 42 which includes the overall desired geometry and importantly a radiused tip 46. The radiused outer edges 45a and 45b of the stile 41 are milled (via a router) by the use of router bit 43 which includes the overall desired geometry and importantly a radiused recess 47a for edge 45a and radiused recess 47b for edge 45b. The primary location or site for the possibility of any chipping and/or splintering (in the prior art constructions) is along these two outer edges of the stile. In the preferred embodiment, these two edges are edges 45a and 45b (see
Since stile edge 45a will be visible on one side of the panel 60 or article (see
Importantly, it has been learned that by creating or adding a radiused shape (recesses 47a and 47b) to the stile router bit so as to radius edges 45a and 45b, any chipping and/or splintering of the workpiece can be significantly reduced (i.e., almost eliminated). In terms of relative numbers or dimensions, a significant reduction in the amount of chipping and/or splintering begins to show up with a radiused dimension of approximately 0.0312 inches (0.793 mm). Only very slight or modest improvement in the reduction of the amount of chipping and/or splintering is realized as the radius dimension increases up to approximately 0.156 inches (3.968 mm). Accordingly, radiuses in this range are seen as achieving the objective for the disclosed router bit designs. The selected radius dimension must also take into consideration the size of the workpiece and the dimensions of the tenons and mortises. Having too large of a radius would create other milling issues and concerns, such as the relative sizes of the tenons and mortises. The radiused geometry of edge 48 which is incorporated into the router bit 42 for the rail 40 creates the inside corner or recess 44b of the rail which receives edge 45b. Essentially the rail is milled to fit the pattern which is cut or milled for the stile 41. Other portions of each router bit include the shank 50, bearing 51, and hex nut 52.
Since the assemblies of
For the stile router bit 43, the first cutting member 55 is received by shank 50 and the second cutting member 56 is also received by shank 50 and is adjacent to the first cutting member 55. The adjacent stacking of cutting members 55 and 56 as received by shank 50 enable the proximity of these two cutting members to cooperatively define radiused recess 47a. Further, radiused recess 47b is defined by and a part of cutting member 55. Radiused recess 47b results in the rounded or radiused outer edge 45b in the
As used herein, “radius” is intended to cover a rounded or curved shape with some point of that rounded or curved shape having a uniform or constant radius dimension. The key though is a smooth and continuous curvature for the router bit recesses which create the curved or rounded (i.e., radiused edges 45a and 45b) in the stile workpiece. While the terms “rail” and “stile” have been selected and used based on how these terms are normally defined, these terms could be reversed without any practical change or consequence to what has been described. Whichever workpiece provides edges 45a and 45b, whether it is called rail or a stile, since horizontal and vertical orientations can be flipped, it is those protruding edges which have the risk of chipping or splintering unless radiused according to the disclosed embodiments.
Further, while only the rail and stile profile has been selected for disclosing and illustrating the selected embodiment, the issues are essentially the same regardless of the selected profile and the solution, according to the selected embodiment, is essentially the same. Each of the profiles in
While the preferred embodiment of the invention has been illustrated and described in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.
This application claims the benefit of U.S. Provisional Application No. 61/368,829 filed Jul. 29, 2010, which is incorporated herein by reference.
Number | Name | Date | Kind |
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5203389 | Goodwin | Apr 1993 | A |
7316529 | Phillips et al. | Jan 2008 | B2 |
Entry |
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Component Male and Female Sets, www.lrhent.com, LRH Enterprises, Inc. Jun. 16, 2010. |
Freud Using your Premier Adjustable Rail and Stile System, www.freudtools.com, Jan. 19, 2010. |
MLCS Router bits and woodworking products, co-publisher: Katana, Jun. 2, 2010 www.mlcswoodworking.com. |
Number | Date | Country | |
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61368829 | Jul 2010 | US |