Panel routing method and means

Panel raising is accomplished with an elongate router cutter tool working against a workpiece or panel which is supported edgewise on the working surface of a work table.

BACKGROUND OF THE INVENTION 
This invention relates to panel raising, and particularly to the 
manufacture in small cabinet shops and the like of raised panels and 
similar pieces by means of routing as an economical alternative to use of 
a shaper. 
PRIOR ART 
Raising a panel is a way to give a rich panelled effect to an otherwise 
starkly rectangular board and, if desired, to render it mountable in the 
styles of a frame, by shaping the cross sections of the board edges to 
give the effect of a raised central panel surrounded by a border of 
relatively thin dimension. The cross-sectional pattern of the edge of a 
raised panel typically has a ogee (S-shaped) configuration, or 
alternatively a smooth concavity whose radius decreases toward the center 
of the panel, although other shapes may be employed. 
For reasons of economy related to scale, routing rather than shaping has 
long been used by the home hobbyist and a small cabinet shop operator for 
raising panels and similar pieces. The present invention is an improvement 
in methods of using router tools rather than shaping tools to shape panel 
board edges. 
In prior art use of router tools rather than shaping tools to shape panel 
board edges, the economy of routing rather than shaping when operating on 
a small scale was indeed realized. However, since the cross-sectional 
pattern of the raising cut typically extends across the length or width of 
the panel further than it does across the thickness of the panel, the 
practice was to use vertically spindled upwardly directed router bits 
whose working profiles were typically much wider than their height. This 
in turn dictated the use of wide, squat bit shapes. The relatively great 
width of such bits corresponded to tip speeds of say about 26,000 feet per 
minute, speeds which, if not unsafe, were at least perceived by users to 
be undesirable from a safety standpoint, thereby limiting sale and use of 
router tools for raising panels. 
Furthermore, the width of the router tools of the prior art, typically 31/2 
inches 988.9 mm), often required special large-diameter insert plates or 
adapters be used on the router table. 
SUMMARY OF THE INVENTION 
The present invention realizes the advantages of using routing tools rather 
than shaping tools to shape panel board edges, but in a manner and with 
tools and set-ups that involve much slower tip speeds of the router bit 
than the prior art, resulting in greatly reduced tip speeds as compared to 
the prior art, reductions to say about 7600 feet per minute. With such 
greatly reduced tip speeds, the present invention provides a routing means 
and method whose perceived safety is much greater than that of the prior 
art. 
Furthermore, the invention enables the use of a router table having only a 
standard or relatively small opening for the router tool. There is no need 
for special large-diameter insert plates or adapters. 
Still further, the invention makes possible adjustment of the profile cut 
by a router tool, so that the profile may be readily set anywhere between 
say 1 inch to 11/2 inches (25.4 mm and 38.1 mm) of reveal by simply 
raising or lowering the tool in the router chuck. 
These benefits are accomplished with an upwardly directed vertically 
spindled tool that is fully compatible with use of a conventional routing 
table. Such a table easily can be set up to practice the invention without 
the necessity for any special table modifications. Furthermore the tool 
may be manufactured substantially as economically, or even more 
economically, than the wide, squat bit shapes employed in prior art 
methods. 
Consequently, the perceived safety advantages of the present invention are 
provided at substantially no greater cost than is associated with the 
practices of the prior art. Therefore, in the practice of the invention, 
the economic advantage of using routing tools rather than shaping tools is 
realized as fully as in the practices of the prior art but with greater 
perceived safety, and without the need for special insert plates or 
adapters, and with the further advantage of ready adjustability of the 
degree of extension of the profile across the reveal. 
The advantages and features of the invention will be more fully understood 
from the following detailed description of one example.

DETAILED DESCRIPTION OF THE INVENTION 
In order that the invention may be most readily described and understood, 
there will first be described the conventional practice of the prior art 
upon which the invention improves. Typical prior art methodology in panel 
raising by use of a router bit is illustrated in FIG. 3. A workpiece or 
wood panel 10 is supported on the working surface 12 of a worktable 14. 
The workpiece slides along the working surface and is guided in its 
sliding movement by guide means such as the guide fence 16a which has a 
cut-out or opening 22a to receive a tool. A tool shank 18 projects 
upwardly through an opening 20 in the worktable 14. The tool shank is 
powered by the motor 24 which is mounted beneath the worktable. The shank 
is removably received in a motor chuck 26 as shown. 
In the illustrated typical practice of the prior art, the tool shank forms 
part of a tool comprising a wide squat router bit or cutter 28. The cutter 
is deployed immediately adjacent the working surface 12 and projects above 
it. The cross-sectional pattern to be cut is defined by the profile 
between the endpoints P1 and P2 shown in FIG. 3, such profile being the 
silhouette of the surface of revolution generated by that portion of the 
cutter that contacts the workpiece. As is typical, and as can be seen in 
FIG. 3, the cross-sectional pattern or profile P1--P2 extends across the 
width W of the workpiece 10 (i.e., across the reveal) further than it does 
across the thickness T of the workpiece. In this typical priorart example, 
the tool includes a ball-bearing pilot 29 which rolls against the unworked 
portion of the edge of the workpiece from which material is being removed. 
While often satisfactory results may be obtained by the conventional 
panel-raising method illustrated, the radius of the cutter 28 is 
relatively great, and at typical motor speeds, the tips of the cutter 
travel at, say 26,000 feet per minute. As previously indicated, operation 
of a tool at such tip speed, if not unsafe, is at least perceived by users 
to be undesirable from a safety standpoint, thereby limiting sale and use 
of such tools. Also, special adaption of the router table may be required 
to accommodate the wide tool. 
According to the present invention, the practice of the prior art just 
described is replaced by providing an elongate cutter tool which has a 
working profile with a relatively long longitudinal dimension and a 
relatively short radial dimension, as illustrated in FIG. 1. In FIG. 1, 
elements like those already described in the foregoing description of FIG. 
2 are given the same reference numerals, and unlike elements are given 
different reference numerals. 
Thus in practicing the invention, and as shown in FIG. 1, there may be 
provided the same worktable 14 having working surface 12, and a guide 
fence 16 differing from the guide fence 16a only in that the cut-out or 
opening 22 may be of smaller longitudinal extent than the opening 22a and 
must be higher than the opening 22a in order to accommodate a different 
shape of tool, and the fence must be of sufficient height to support an 
on-edge workpiece. (However, if the opening in a prior art guide fence 
happens to be large enough to accommodate the tool shapes of the invention 
as well as those of the prior art, and if the fence is also of adequate 
height, such fence can be used in the practice of the invention with no 
change whatsoever.) 
Again, the tool may be driven by a motor 24 provided with a suitable chuck 
26 to receive the tool shank which extends upwardly though the opening 20 
in the worktable. This identity between much of the equipment usable in 
the practice of the present invention and that used in the prior art for 
raising panels by routing means that the advantages of the invention are 
realized at substantially no increased cost over the practices of the 
prior art. 
The practice of the invention differs from the prior art in the use of an 
elongate router cutter tool such as the tool 48 shown in FIG. 1, in the 
positioning and supporting of the workpiece or panel 10 edgewise on the 
working surface 12, and in other respects described below. 
As can be seen in FIG. 1, the elongate router cutter tool 48 is combined in 
one piece, and with its own integral shank 38 mounted in the motor chuck 
26. The length of the shank (the total extent of which is not shown in the 
drawings) is at least half as long as the tool proper and is preferably 
approximately equal to the length of the tool proper. The working profile 
of the cutter tool in FIG. 1 is shown to have an ogee (S-shaped) 
configuration, since this is a commonly used profile shape in panel 
raising and, for purposes of comparison, such working profile is also 
shown to be the same as the profile of the prior-art tool 28 shown in FIG. 
3. Another cutter tool 48a which may be used in the practice of the 
invention is shown in FIG. 1A. This tool has a working profile which 
defines in the workpiece a smooth concavity. These working profiles of the 
tools 48 and 48a are typical of those used for panel raising in that the 
slope of the profile, with respect to the tool axis, is unidirectional 
generally throughout the length of the profile. Thus, in both illustrated 
working profiles, the slope of the profile between points P1 and P2 is 
non-negative generally along the entire length or axial extent of the 
working profile. Such characteristic would be also be true of other 
typical working profile shapes used in panel raising. 
Points P1 and P2 in FIG. 1 are spaced from each other identically to points 
P1 and P2 in FIG. 3 for comparison of the invention with the prior art 
with respect to an identical profile. However, the actual working profile 
may be readily adjusted in the extent to which it extends across the 
reveal (i.e. across the W direction) by simply raising or lowering the 
shank 38 in the chuck 26. If the shank is raised from the illustrated 
position to the point that the bottom corner or skirt of the tool 48 is 
level with the working surface 12 of the worktable, the total working 
profile of the tool is employed. As the shank 38 is adjusted to lower and 
lower positions in the chunk, the total working profile of the tool is no 
longer employed, and the actual working profile of the set-up is 
progressively reduced. This adjustment may extend throughout a range of 
say 1/2 inch (12.7 mm) to thereby correspondingly adjust the profile cut 
by the tool to any desired setting within that range. 
The total working profile of each of the tools 48 and 48a has a relatively 
long longitudinal dimension and a relatively short radial dimension, and 
each of these tools is vertically spindled so as to position a substantial 
portion of its total working profile above the working surface 12 (to 
thereby define the actual working profile), with the working profile of 
the tool extending upwardly to the free end of the tool at a height above 
the working surface greater than the thickness T of the workpiece. 
It is to be noted that each of the resulting tools has a total working 
profile whose slope, with respect to the tool axis, is unidirectional 
generally throughout the length of the tool, and a profile that is longer 
in the axial direction than the diameter of the working end of the tool. 
Typical height dimensions of the total working profile are from about 1.75 
to 3 inches (44.5 mm to 76.2 mm). Typical major radii are from about 0.4 
to 0.75 inches (10.2 to 9.0 mm). Router bit tools combining these 
dimensions and shapes are believed to be novel. 
Again, the cross-sectional pattern to be cut is defined by the profile 
between the endpoints P1 and P2, such profile being the silhouette of the 
surface of revolution generated by that portion of the cutter that 
contacts the workpiece. However, the relatively long longitudinal 
dimension of the vertically spindled cutter tool 48 of FIG. 1 or 48a of 
FIG. 1A extends the cross-sectional pattern between the points P1 and P2 
predominately in the vertical direction across the width W of the on-edge 
workpiece 10. This is in marked contrast to the prior art as seen in FIG. 
3, in which the cross-sectional pattern or profile P1-P2 extends 
predominately in the horizontal direction across the width W of the 
face-down workpiece 10. 
The predominately vertical orientation of the cross-sectional pattern makes 
possible the utilization of a vertically elongate cutter such as cutter 48 
whose relatively small radial dimension correlates with relatively low tip 
speeds and the advantages attendant thereon. 
As seen in FIGS. 1 and 1A, the cutter tool proper of each cutter tool 48, 
48a has a center of gravity toward its shank end so that its free end is 
of relatively low mass as compared to its shank end whereby it has an 
elongate shape and still has sufficiently low free end dynamic flexure to 
hold acceptable cutting tolerances throughout its length including its 
free end. This low free-end dynamic flexure is exploited as shown in FIGS. 
1 and 1A by positioning a substantial portion of the total working profile 
including the free end of the tool above the horizontal worktable surface 
12 with the vertical distance of the free end of the tool above the 
worktable surface approaching the full elongate extent of the cutter-tool 
proper and exceeding the major outside diameter of the cutter-tool proper 
to thereby, consistently with acceptable cutting tolerances, define a 
cross-sectional pattern that extends across the length or width of a panel 
further than the cross-sectional pattern is to extend across the thickness 
of the panel. 
In the foregoing description, terms such as "vertically," "horizontally," 
and "above" are used because it is common practice to use a vertical tool 
spindle and a horizontal work surface. However it is to be understood that 
these terms are used in the following claims in a broad and relative sense 
so as to apply, for example, to methods practiced on the set-up 
illustrated in FIG. 1 even if that set-up were for example rotated 
forty-five or ninety degrees in the counterclockwise direction, at which 
new positions the set-up would still be operative. 
The invention is not limited to the specific details of the illustrated 
example, but is defined by the following claims.