Not Applicable
1. Field of the invention
This invention relates to the field of accessories for table saws, band saws, router tables and other woodworking machinery, and particularly to featherboards for table saws, band saws, router tables and other woodworking machinery.
2. Description of the Prior Art
A featherboard is a device used when working with stationary routers, table saws or band saws. A featherboard helps ensure an accurate cut by pressing a work piece against the table or the guide fence as the work piece moves past the cutting blade. Additionally, a properly designed featherboard is a safety device, which prevents the work piece from kicking back at the operator should the cutting blade bind up in the work piece. Generally, a featherboard that presses a work piece to the table is secured to the guide fence and a featherboard that presses a work piece to the guide fence is secured to the table. See, for example, U.S. Pat. No. 481,983 (1892), U.S. Pat. No. 534,447 (1895), U.S. Pat. No. 1,022,176 (1912), U.S. Pat. No. 2,612,914 (1952), U.S. Pat. No. 2,699,804 (1955), and U.S. Pat. No. 6,619,347 (2003).
The most common means by which a featherboard is secured to the table is to position it in the miter slot or T-slot and lock it in place. See, for example, U.S. Pat. No. 2,722,247 (1955) and U.S. Pat. No. 4,476,757 (1984). The slot is typically within 6 inches of the cutting blade, which limits the width of the work piece that can be used with the featherboard. A featherboard may also be held in place with a strong magnet. This allows for a wider work piece than the miter slot featherboard because the magnet can be positioned anywhere on the table, but only if the table is flat and ferrous. Since many tabletops are manufactured from aluminum, and side extension tables may be made from wood, aluminum, corrugated steel or even plastic, especially if home built, this device will not work with all machines.
U.S. Pat. No. 3,457,972 (1969) describes a long-reach featherboard that mounts to the worktable using a spline pin that fits into a spline receptacle. The entire length of the arm functions as the spring that holds the work piece to the guide fence.
The invention is an improved woodworking accessory for keeping a work piece pressed tightly against the guide fence on a table saw, stationary router or band saw. The invention features a unique bracket that allows the invention to be quickly and securely attached to a worktable without tools. It also has an arm that is held in the bracket. At the end of the arm is a flexible plate that acts as a spring to assert pressure against a work piece moving through a saw blade, for example.
a is an exploded view of the featherboard arm and flexible plate.
a is top view showing the featherboard arm with one flexible plate.
b is top view showing the featherboard arm with three flexible plates in a triangle configuration.
c is a top view showing the featherboard arm with three flexible plates in a step configuration.
d is top view showing the featherboard arm with two flexible plates, spaced apart.
The flexible plate 5 is made of thin, flexible material. The featherboard arm 3 must be sufficiently rigid that it does not bend as it presses the work piece against the guide fence. In the preferred embodiment, square aluminum pipe ¾″×¾″ is the preferred material because it slides freely inside the 1″ square steel pipe made (used as a bracket, see below) with little free play. The featherboard arm 3 can be made any length and can be sized to the width of a particular table saw.
a is an exploded view of the featherboard arm 3 and a single flexible plate 5. As discussed above, a slot 6 is cut in the distal end of the featherboard arm 3 to receive the flexible plate 5. A hole 10 is drilled through the end of the featherboard arm 3 for the screw 7. A corresponding hole 11 is formed in the back end of the flexible plate 5. The machine screw 7 and a hex nut 8 are used to fix the flexible plate 5 to the featherboard arm 3. Should the flexible plate be damaged it can be easily removed and a new flexible plate installed.
In the preferred embodiment, individual flexible plates are made from a material that is both flexible and tough, such as 1/16″ LEXAN. In this figure, the guide marks 9 on the flex plate 5 are shown. As noted above, they help position the featherboard arm 3 with respect to the work piece 102.
a-3d show several configurations that achieve various degrees of flexibility and work piece pressure.
b is an exploded top view showing the featherboard arm with three flexible plates in a pyramid configuration. In this view, the featherboard arm 3 has a wider slot 6 to accommodate three flexible plates. The center flexible plate 5 is the same length as that of the single flexible plate of
c is an exploded top view showing the featherboard arm with three flexible plates in a step configuration. Here, the featherboard arm 3 also has a wider slot 6 to accommodate three flexible plates. The top most flexible plates 5b and 5c are shown each being shorter than the last. As before, the flexible plates are secured with a screw 7 and hex nut 8.
d is an exploded top view showing the featherboard arm with two flexible plates, spaced apart. In this configuration, the featherboard arm 3 has two slots 6a and 6b that are a single width wide and are spaced apart as shown. Two, equal length, flexible plates 5 are placed in the slots and are secured with a screw 7 and hex nut 8, as before.
The edges of the flexible plate presses into the side of the work piece, preventing it from moving backward. This is an additional safety feature that further eliminates kickback.
A bracket mounting piece 19 consists of a piece of 1″×1″ steel angle stock that is 4″ long. The purpose of the bracket-mounting piece is to fit securely over the edge of the worktable to provide mechanical stability to the featherboard. The arm guide 16 is welded to the bracket edge as shown. There is an elongated slot 20 in the bracket-mounting piece 19 as shown.
To install the mounting bracket 15, the following steps are used. First, place the bracket-mounting piece 19 on the edge of the worktable 105 in the desired location with the bracket mounting piece 19 flush with the worktable edge. In this position, the center of the elongated slot 20 will be ½″ from the edge of the table. Second, mark the location of the hole. Third, drill a ¼″ diameter vertical hole 21 into the worktable on the mark. Fourth, a machine screw 22 is passed through the elongated slot 20 in the bracket edge and then loosely threaded into a ¼″ diameter tapped standoff 23. The machine screw can be moved back and forth within the slot so that the bracket-mounting piece 19 is perfectly flush with the table edge when the standoff is placed in hole 21. Finally, the machine screw is tightened to fix the position of the standoff
Once the standoff 23 is secured to the bracket-mounting piece 19 it may then be lifted off the table and then returned to its working position at any time without any tools. The combination of the bracket edge and the standoff make the bracket very stable and rugged under any anticipated load.
The bracket plate 24 may also be installed on the edge of a worktable 105 as shown in
Although the drawing figures show this tool in use with a table saw, the tool can be used equally well with band saws, router tables and other woodworking machinery in exactly the same way as illustrated. Once the tool is attached to the particular machine bed, the position of the featherboard arm 3 can be adjusted for a particular work piece and machine and the operation of woodworking can begin.
While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
This application claims benefit of Provisional application 61/426,591 filed Feb. 4, 2011.