Router table joint making machine

#This invention relates to methods and apparatus for forming woodworking joints, especially dovetail and similar joints, and it relates more particularly to devices and techniques for enabling such joints to be cut utilizing a router.

#Wooden boxes, drawers and storage chests and a variety of other wooden furniture and other objects often use dovetail joints as a means of securely assembling the sides. Dovetails are used for both their decorative nature and their high strength. Such joints can be made without industrial machinery in one of two principal ways, either using hands tools: saws and chisels, or using power tools such as a router. In both cases, making such a joint requires a high degree of skill and precision, and in the case of hand tools, time. The desire to save time drives most woodworkers towards the use of power tools, and the need for precision, often in the relative absence of skill, makes jigs or machines that control the power tools desirable.

#There are two basic approaches possible when using a router. The router can be held stationary and the workpiece moved relative to the position of the router cutter, or the workpiece can be held stationary and the router moved relative to the workpiece. Additionally, in a variation of both basic approached, both the router and the workpiece can be moved.

#FIG. 1 is a perspective view of the joint making machine of this invention shown mounted on a router table top.

#FIG. 2 is an exploded perspective view of the principal components of the joint making machine of this invention.

#FIG. 3 shows the relationship among a dovetail tailboard, pin board, cutter, and template of this invention.

#FIG. 1 illustrates an exemplary joint making machine 101 of this invention mounted on a router table top 619, and FIG. 2 illustrates the machine 101 in an exploded perspective view. For simplicity, threads are not shown in the drawings on all of the components in the exemplary embodiment that are threaded.

#Operating Principles

#For joints including a pair of panel shaped workpieces, each workpiece end can be classified as either a tailboard or a pin board. Tailboards, such as tailboard 102 in FIGS. 21 and 3, result from passing a cutter through (or at least into) the board in a straight line leaving a void having the profile of the cutter. Pin boards, such as pinboard 104 in FIGS. 21 and 3 are the result of removing material from a workpiece except where a template prevents material removal. Template shape determines the end or cross sectional shape of the pin board pins. Template shape is directly related to the shape of the cutter used producing the tailboards. This principle is illustrated in FIG. 3, which shows use of a ⅞″ 14° dovetail cutter 302 with a dovetail-shaped template 304 with 14° sides 306 and a nominal width 308 of ⅞″. The template (such as template 304) determines the shape of the dovetail pins, and the dovetail cutter determines the shape of the tails.