Horizontal hold down jig

A horizontal rotary hold down jig for use in horizontally guiding a piece of wood to be cut on one of a portable table saw and a portable router table comprising a spring biased rotatable wheel that can be secured to the table. The spring biasing can be adjusted to provide uniform or enhanced pressure through use of a plurality of substitutable compression springs of varying compressive strength characteristics to laterally stabilize a piece of wood of varying consistency, wood grain angle, feed cutting speed, width, and thickness or depth of cut.

BACKGROUND OF THE INVENTION

Many woodworking methods such as routing, joining and cutting involve the step of moving a workpiece past a rotating cutting tool. These operations are typically performed on a woodworking machine having a table. Examples of such machines include routertables, shapers, joiners, jointers, and table saws. Examples of rotating cutting tools include saw blades and router bits.

When performing a woodworking operation on a table such as routing, joining and cutting the machine operator must control the path of the workpiece as it moves relative to the cutting tool. The motion of the workpiece is typically guided in whole ore in part by hand. In some cases a motion guide may be utilized to aid the machine operator in guiding the motion of the workpiece. Examples of motion guides include fences, and featherboards.

A fence is typically an elongate metallic member which is fixed to the table of a machine. The fence typically includes an elongate, flat guiding surface which is oriented at a ninety degree angle to the top surface of the table. A workpiece may be held by the hands of the machine operator against the guiding surface of the fence as the workpiece is moved past the cutting tool.

A stop controls the movement of the workpiece by blocking its path. A stop may be used to position a plurality of workpieces in the same longitudinal position so that consistency can be achieved. This is particularly useful for repetitive operations, such as when several pieces of wood must be cut to equivalent length for cabinetry.

A feather board is a motion guide which may be utilized to prevent an occurrence known in the art as kickback. Kickback occurs when the workpiece binds to a cutting tool, for example the blade of a table saw. As a workpiece is cut on a table saw, the blade removes material from the workpiece creating an elongate kerf through the workpiece. Residual stresses within the workpiece sometimes cause the material of the workpiece to close around the blade. A portion of the workpiece may bind to the blade, causing the workpiece to be carried along with the blade as it rotates at high speed. When kickback occurs, the workpiece is thrown upwardly and rearwardly toward the body of the saw operator. The workpiece may strike the unfortunate operator causing bodily injury.

A feather board may include a plurality of pawls. The pawls are typically biased so that they ride over a surface of the workpiece as it is fed in a forward direction past the cutting tool. When a kickback situation arises, the workpiece begins movement in a reverse direction causing a corresponding rotation of the pawls. As the pawls rotate, they may jam the workpiece against a fence mounted on the table of the machine, thereby preventing any further reverse movement.

A table saw or sawbench is the most common piece of large woodworking equipment used by individual craftsmen. Because of its versatility, when only one piece of large woodworking machinery is owned, it will often be a table saw. The saw consists of a circular saw blade, mounted on an arbor, that is driven by an electric motor (either directly or by belt or gears). The blade protrudes through the surface of a table, which provides support for the material (usually wood) being cut.

In modern table saws, the depth of the cut is varied by adjusting the amount of the blade that protrudes above the table surface: the higher the blade protrudes above the table, the deeper the cut that is made in the material. In some early table saws, the blade and arbor were fixed, and the table was moved up and down to expose more or less of the blade. The angle of cut is controlled by adjusting the angle of blade. Some earlier saws angled the table to control the cut angle.

The central tool in almost all cabinetmaking shops is the table saw, probably the most useful single tool the average woodworker is going to have, because the work it does serves as a base for all that comes afterward. Used for sizing wood, the table saw may be seen primarily as a ripping machine, but it does so much else any woodshop without one can seem badly under equipped. Ripping boards to width is one job that is exceptionally important in most projects, but the table saw goes on to cut sheets of plywood, make crosscuts, do miter and bevel cutting and a host of other jobs, just as it comes from its maker. With jigs, the table saw works to make tenons, crosscut wide or very long lumber, make repetitive cuts, cut grooves and slots and molding and much else, including cutting raised panels.

There are two distinct types of router; the plunge router and the fixed (or standard) router. Both types can offer the same end results, although each type is better for particular jobs. The plunge router is especially useful when the routed area begins in the middle of the wood, rather than at the edge. The maximum plunge depth can be set so that you slowly lower the router bit into the wood while keeping the router flat on the wood's surface. While a fixed router can also be used in this example, the router cut depth is fixed and you must hold the router at an angle as you slowly allow the router bit to cut into the wood. This is not as accurate for small routs.

The fixed router is far better for routs along the edge of a piece of wood. The fixed router is also better for any time when the depth of the cut must be very accurate. Fixed routers allow very small increases in the depth of cut and are far more accurate than plunge routers. Further, if you are considering attaching your router to a router table, a plunge router is not suitable. If you only have the budget for one router, we recommend that you start with a fixed router. Routers are typically used to cut grooves, hollow out larger areas and create decorative trims along the edge of a piece of wood. The shapes that can be cut by your router are limited only by the number of router bits that you own.

ADVANTAGES OF THIS INVENTION

This invention relates to a horizontal hold down jig for use in horizontally guiding a piece of wood to be cut on one of a portable table saw and a portable router table having a moveable rip fence. Typically, the rotating cutting wheel will laterally displace the piece of wood being cut. To alleviate this problem, and others which will become apparent from the disclosure which follows, the present invention conveniently can apply a uniform rolling horizontal pressure to the piece of wood being cut to keep it from being laterally displaced.

Still other advantages will be apparent from the disclosure that follows.

SUMMARY OF THE INVENTION

According to the invention, a horizontal hold down jig and a kit therefore, for use in horizontally guiding a piece of wood to be cut on one of a portable table saw and a portable router table having a moveable rip fence, comprising a rotatable wheel secured proximate a distal end of a first tension arm, a base plate rotatably connected to a proximate end of the first tension arm, means to secure the base plate of the jig to a table, spreader means for positioning the rotatable wheel at a spaced distance from the base plate when the base plate is secured to the table, and spring biasing means for disposing the rotatable wheel along side the piece of wood, in which the base plate of the jig can be secured to the table with the rotatable wheel disposed in the direction of the piece of wood to be cut, the first tension arm can be adjusted by the spreader means to positioning the rotatable wheel along side the piece of wood, so that the rotatable wheel applies spring biased pressure on the piece of wood before and during the cutting operation.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent that the invention may be practiced without these specific details.

Without departing from the generality of the invention disclosed herein and without limiting the scope of the invention, the discussion that follows, will refer to the invention as depicted in the drawing.

According to one embodiment, a horizontal hold down jig1, for use in horizontally guiding a piece of wood51to be cut on one of a portable table saw53and a portable router table having a moveable rip fence55, comprising a rotatable wheel2secured proximate a distal end of a first tension arm3, a base plate4rotatably connected to a proximate end of the first tension arm, means to secure5the base plate4of the jig to a table57, spreader means6for positioning the rotatable wheel2at a spaced distance from the base plate4when the base plate is secured to the table57, and spring biasing means7for disposing the rotatable wheel2along side the piece of wood51is taught.

In this way, the base plate4of the jig1can be secured to the table57with the rotatable wheel2disposed in the direction of the piece of wood51to be cut, the first tension arm3can be adjusted by the spreader means6to positioning the rotatable wheel2along side the piece of wood51, so that the rotatable wheel applies spring biased pressure on the piece of wood before and during the cutting operation.

Preferably, the means to secure5the base plate4of the jig to a table comprises an elongated bar8with an elongated cut18extending from a first end that is attached to the underside of the base plate4and a first locking screw10with a tapered section along a portion of its length and a primary nut12for engaging the first screw. The first screw10can be disposed in the elongated cut18and tightened with the primary nut12to encourage a broader portion of the tapered section of the first screw into the elongated cut to spread the first end of the elongated bar8to secure the elongated bar in a miter slot59of the table57.

As shown inFIG. 2, the means to secure5the base plate4of the jig1to a table57may comprise at least one clamp14tightened to hold the base plate4to the table. Moreover, as shown inFIG. 1, the rotatable wheel2preferably has a vertical axis and each end of said axis is secured proximate the distal end of the first tension arm3.

Referring toFIGS. 1 and 2, the spreader means6comprises an externally threaded adjustable rod9that is pivotally attached on a first end9aof the rod to the first tension arm3and that engages an aperture20in the base plate4that is suitably sized to receive the rod9, and a complementary nut16and a wing nut30suitably sized to engage the threaded rod9, said complementary nut and wing nut can respectively be disposed on either side of the aperture20of the base plate4to limit the range of pivotal movement of the first tension arm3relative to the base plate4.FIG. 2shows the aperture20comprising an elongated slot. Alternatively, the aperture20may comprise a plurality of horizontally adjacent holes, as shown inFIG. 3A.

Moreover, the spreader means6, as shown inFIGS. 1-3, comprises an externally threaded rod9with an eyelet22disposed on a first end9a,a first nut24and bolt26, at least one hole28in the first tension arm3that is suitably sized to receive the bolt26, at least on aperture20in the base plate4that is suitably sized to receive the rod9, a complementary nut16and a wing nut30suitably sized to engage the threaded rod9, said complementary nut and wing nut can respectively be disposed on either side of the aperture20of the base plate4to limit the range of pivotal movement of the first tension arm relative to the base plate.

Additionally, the spring biasing means7may comprise at least one compression spring32suitably sized to stabilize the piece of wood51to be cut with the rotatable wheel2. Preferably, the spring biasing means comprises one of a plurality of compression springs32from a group of compression springs of varying compressive strength characteristics which are suitably sized to laterally stabilize a piece of wood to be cut on a table with the rotatable wheel from a group of pieces of wood of varying consistency, wood grain angle, feed cutting speed, width, and thickness or depth of cut, as shown inFIG. 4.

As is evident inFIGS. 1-3, the spring biasing means7may be integrally connected to the spreader means6. As shown inFIG. 3-4, the spring biasing means7may comprise a compression coil spring32having an internal radius and the spreader means6comprises an externally threaded rod9that is pivotally attached on a first end9aof the rod to the first tension arm3and that is suitably sized to pass through the internal radius of the coil spring32and through an aperture20in the base plate4, and a complementary nut16and a wing nut30each having an internal thread that is suitably sized to engage the threaded rod9and each having a transverse dimension that is larger than the aperture20, said wing nut30being threaded onto the rod9to allow a second end9bof the rod to pass through the internal radius of the coil spring32and then through the aperture20, and the complementary nut16being disposed onto the second end9bof the rod to limit the range of pivotal movement of the first tension arm3relative to the base plate4. Furthermore, locating the wing nut30further from the first end9aof the rod increases the pressure of the rotatable wheel2on the piece of wood51to be cut, whereas, locating the wing nut30closer to the first end9aof the rod allows a wider piece of wood to be cut. To adjust for lateral pressure needs to keep the workpiece aligned, another spring32having different compressive strength characteristics may be employed.

Preferably, the spring biasing means7of the jig1has one of a plurality of compression springs32from a group of compression springs of varying compressive strength characteristics that can be interchanged on the jig to laterally stabilize the piece of wood to be cut on the table.

A preferred embodiment of the horizontal hold down jig, for use in horizontally guiding a piece of wood to be cut on one of a portable table saw and a portable router table having a moveable rip fence, has:a. a rotatable wheel2secured proximate a distal end3aof a first tension arm, said wheel2having a vertical axis and each end of said axis is secured proximate the distal end of the first tension arm3;b. a base plate4rotatably connected to a proximate end3bof the first tension arm3;c. means to secure5the base plate4of the jig1to a table57comprises one of an elongated bar8with an elongated cut18extending from a first end8athat is attached to the underside of the base plate4and a first screw10with a tapered section along a portion of its length and a primary nut12for engaging the first screw, said first screw can be disposed in the elongated cut18and tightened with the primary nut12to encourage a broader portion of the tapered section of the first screw10into the elongated cut18to spread the first end of the elongated bar8to secure the elongated bar in a miter slot59of the table57, and at least one clamp14tightened to hold the base plate4to the table;d. spreader means6for positioning the rotatable wheel at a spaced distance from the base plate when the base plate is secured to the table, said spreader means comprising an externally threaded rod9that is pivotally attached on a first end9aof the rod9to the first tension arm3and that engages an aperture20in the base plate4that is suitably sized to receive the rod9, and a complementary nut16and a wing nut30suitably sized to engage the threaded rod9, said complementary nut and wing nut can respectively be disposed on either side of the aperture of the base plate4to limit the range of pivotal movement of the first tension arm3relative to the base plate4;e. spring biasing means7, for disposing the rotatable wheel2along side the piece of wood51, comprising one of a plurality of compression springs32from a group of compression springs of varying compressive strength characteristics which are suitably sized to laterally stabilize a piece of wood to be cut on a table with the rotatable wheel from a group of pieces of wood of varying consistency, wood grain angle, feed cutting speed, width, and thickness or depth of cut; andf. said spring biasing means7being integrally connected to the spreader means6,
whereby, the base plate4of the jig1can be secured to the table57with the rotatable wheel2disposed in the direction of the piece of wood51to be cut, the first tension arm3can be adjusted by the spreader means6to positioning the rotatable wheel2along side the piece of wood, so that the rotatable wheel applies spring biased pressure on the piece of wood before and during the cutting operation.

Preferably, the spring biasing means7comprises a compression coil spring32having an internal radius and the spreader means6comprises an externally threaded rod9that is pivotally attached on a first end9aof the rod to the first tension arm2and that is suitably sized to pass through the internal radius of the coil spring32and through an aperture20in the base plate, and a complementary nut16and a wing nut30each having an internal thread that is suitably sized to engage the threaded rod9and each having a transverse dimension that is larger than the aperture20, said wing nut30being threaded onto the rod9to allow a second end9bof the rod to pass through the internal radius of the coil spring32and then through the aperture20, and the complementary nut16being disposed onto the second end9bof the rod to limit the range of pivotal movement of the first tension arm relative to the base plate.

Additionally, as shown inFIG. 5, a kit34for laterally stabilize the piece of wood51to be cut on the table57is taught by this important invention. The kit34comprises a horizontal hold down jig1having a rotatable wheel2secured proximate a distal end3aof a first tension arm3, a base plate4rotatably connected to a proximate end3bof the first tension arm, means to secure5the base plate4of the jig to a table, spreader means6comprising an externally threaded rod9that is pivotally attached on a first end9aof the rod to the first tension arm3and that engages an aperture20in the base plate4that is suitably sized to receive the rod9, and a complementary nut16and a wing nut30each having an internal thread that is suitably sized to engage the threaded rod9and each having a transverse dimension that is larger than the aperture20, said wing nut30being threaded onto the rod9to allow a second end9bof the rod to pass through the internal radius of the coil spring32and then through the aperture20, and the complementary nut16being disposed onto the second end9bof the rod to limit the range of pivotal movement of the first tension arm3relative to the base plate4, spring biasing means7for disposing the rotatable wheel2along side the piece of wood51, for horizontally guiding the piece of wood to be cut on one of a portable table saw and a portable router table having a moveable rip fence55, and a plurality of compression springs32from a group of compression springs having a transverse dimension that is larger than the aperture20and having varying axial lengths and compressive strength characteristics that can be interchanged on the jig1.

The kit34preferably has each of the compression springs32from the group of compression springs has squared ends32awhich will minimize distortion and the bending of the axis of the spring32. This aspect of the invention coupled with an aperture20comprising either an elongated slot20aor a plurality of horizontally adjacent holes20bwill allow the rod9to maintain perpendicularity with the base plate4of the jig1, to minimize distortion and the bending of the axis of the spring32.

FIG. 7is a detailed perspective view of a rod securing attachment36as shown inFIG. 6. The attachment36is secured to an adjustable threaded rod38, which functions as described previously. The rod38can be secured to the attachment36by any suitable mechanism, such as a welding or threaded coupling. A pair of aligned holes40permit the insertion and securing of a nut and bolt assembly42in such a way as to permit the mechanism to pivot, as previously described.

While this invention has been described in connection with the best mode presently contemplated by the inventor for carrying out his invention, the preferred embodiments described and shown are for purposes of illustration only, and are not to be construed as constituting any limitations of the invention. Modifications will be obvious to those skilled in the art, and all modifications that do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. Those skilled in the art will appreciate that the conception upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

My invention resides not in any one of these features per se, but rather in the particular combinations of some or all of them herein disclosed and claimed and it is distinguished from the prior art in these particular combinations of some or all of its structures for the functions specified.

With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, including variations in size, materials, shape, form, function and manner of operation, assembly and use, and all equivalent relationships to those illustrated in the drawings and described in the specification, that would be deemed readily apparent and obvious to one skilled in the art, are intended to be encompassed by the present invention.