Woodworking – Dovetailing machine – Frusto-conical bit
Reexamination Certificate
1999-02-24
2001-03-27
Bray, W. Donald (Department: 3725)
Woodworking
Dovetailing machine
Frusto-conical bit
C033S197000, C033S638000, C083S468200, C083S468600, C144S085000, C144S135200, C144S137000, C144S144100, C144S204200, C144S371000, C140S039000, C269S303000, C269S306000, C269S315000
Reexamination Certificate
active
06206060
ABSTRACT:
FIELD OF INVENTION
This invention relates generally to the woodworking field and more specifically to a jig system for precisely positioning the placement of multiple cuts made with a cutting tool in a workpiece.
BACKGROUND OF THE INVENTION
Dovetail and box joints are well known methods for joining the side panels of wooden boxes or drawers to their front and back panels. This is accomplished by the use of interlocking joints cut into the ends of each panel where one joins to the other. The interlocking joints are ultimately held together by adhesives.
In ancient times, dovetail and box joints were laboriously cut by hand. Later, with the invention of the router, they were cut by a rotating cutting tool on a router. Cuts were evenly spaced on the ends of wood panels by employing templates which guided the cutter on a hand held router.
With the development of router tables, the router was able to be mounted in a fixed position. Now instead of the router being moved through a wooden panel or workpiece, the workpiece is moved into a stationary cutting tool.
The current state of the art for cutting dovetail and box joints includes jig systems that when secured to a router table help to guide a workpiece into the cutting tool of a router mounted into the table. The workpiece is guided against one side of a fence, which is part of the jig systems, as it is pushed into the cutting tool. The current technologies guide the fence after each cut. Subsequent cuts are then made at very precise locations equidistant from each other along the edge of the workpiece.
Currently, the indexing of the fence is controlled by two technologies. One method uses a lead screw which, when rotated, moves the fence away from the cutter a measured distance. The other technology utilizes a fence attached to one of two racks which face each other. They are held in position by meshing of interlocking teeth and moved a measured distance before each new cut.
These technologies, although improvements, create several problems. For instance, the movement of a fence by means of either racks or lead screws is controlled by templates or scales with graduated markings. As such, an operator must choose the correct scale or template and then precisely line up the graduations with a cursor after each cut is made with the router bit.
Another disadvantage of the present technologies lies in the problem created by the fact that the workpiece can only be presented to the cutting tool from one side of a fence. This is a serious shortcoming because to make a proper dovetail joint, both ends of the workpiece must be cut from the same relative starting point. When both ends of a workpiece are cut on the same side of the fence, as is the case with the current systems, the starting point for a series of joint cuts made on the ends of a drawer's front and/or back panel will be at different places. This results in a misalignment of joints when the drawer is assembled.
A still further disadvantage of the current systems lies in attempts to correct the problem presented by using only one side of a fence for guiding a workpiece. As stated earlier, alignment of the joints is difficult when using only one side of the fence. To overcome this problem, the current systems center the joint cuts on the workpiece. For instance, dovetail cuts are measured from the center of a workpiece out to both ends. As a result, this method restricts the widths of the drawer sides to only those which would permit dovetail cuts to fit completely within the confines of the workpiece. If the dovetail cuts do not fit completely into the confines of a drawer width then a hole can be seen on either end of the drawer side. Clearly, a hole that is visible on the top surface of a drawer side is unacceptable especially in a piece of furniture where fine workmanship is expected.
Another disadvantage of the present technologies includes the use of a plurality of fixed templates that require a specific cutting tool height. However, the accuracy of these systems is decreased by the difficulty encountered in accurately repeating the required placement height of the cutting tool in the router table.
A still further disadvantage of the present technologies includes the inability to use the exhaust port that exists in router table models that are currently available. As such, sawdust collection is not easily accomplished.
Accordingly, what is needed is a jig system that eliminates the cosmetic restrictions placed on the width of a workpiece wherein only certain widths are acceptable; the necessity to rely on one's ability to visually line up graduations on a cursor after each cutting; the plethora of single purpose templates and the inherent inaccuracy due to the difficulty of placing the cutting tool at an exact height in the router table.
SUMMARY OF INVENTION
For purposes of this invention, the terms and expressions below, appearing in the specification and claims, are intended to have the following meanings:
“Pins” as used herein means the front or back of a drawer or box.
“Rails” as used herein means the sides of a drawer or box.
The present invention provides for a jig system that overcomes the problems inherent in the current prior art by providing a row of multi-use adjustable spacers which eliminates the need to visually line up graduations on a cursor for each new cut. The adjustability of these spacers accommodates any desired cutting tool height or size without the need to accurately repeat the exact placement for a specific template. Additionally, the present invention permits a workpiece to be cut on both sides of a guide bar fence which eliminates the need for centering the workpiece.
Accordingly, a principal object of this invention is to provide a simplified and more complete jig system for cutting dovetail and box joints to be used with router tables which are currently available from commercial retailers.
Another object of the present invention is to provide a jig system comprising multi-use adjustable spacers that control the indexing of a workpiece and that can be used with a stationary and/or a portable cutting tool.
Still another object of the present invention is to provide a jig system that permits a workpiece to be cut on both sides of a guide bar fence thereby assuring that the first cut can be made on the same edge of the pin on either end of the pin. This guarantees the results will always be esthetically pleasing regardless of the width of the workpiece.
A further object of the present invention is to provide a jig system that is compatible with existing router tables and utilizes exhaust ports already built into most conventional router tables. Thus, sawdust produced can be quickly removed.
Yet another object of the present invention is to provide a simpler jig system to operate and manufacture. Since no expensive lead screw or rack technologies are utilized in the present invention, it can be produced more cost efficiently thereby bringing this new technology to a wider group of people at a lower price.
The foregoing objects are accomplished with a jig system mounted to a stationary fixture for positioning the placement of multiple cuts in a workpiece, the jig system comprising;
a) a stationary fixture;
b) a spacer bar;
c) a plurality of spacers connecting to the spacer bar, the spacers are adapted for lateral and rotational movement along the spacer bar for positioning the spacers in an engaged and non-engaged working mode;
d) a sliding member for engaging with the stationary fixture comprising:
i) means for moving the sliding member laterally on the stationary fixture; and
ii) means for contacting at least one of the spacers during the engaged working mode; and
e) means for holding and for connecting the spacer bar to the stationary fixture while engaging at least one of the spacers in the engaged working mode.
The means for contacting at least one of the spacers during the engaged working mode may include an extension member attached to the sliding member having opposing surfaces that extend a sufficient length to make contact with
Bray W. Donald
Ellis Howard M.
Fuierer Marianne
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