Cutting – Processes
Reexamination Certificate
2000-05-24
2002-11-19
Dexter, Clark F. (Department: 3724)
Cutting
Processes
C083S468300, C083S468700, C083S471300, C083S473000, C083S477100, C083S581000, C269S319000
Reexamination Certificate
active
06481320
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to holders of decorative articles of wood for holding such articles during the preparative sawing process. More particularly, the invention relates to a holder or jig for holding a crown molding in place during the sawing process in producing miter joints therein.
2. Reported Developments
For certain decorative wood products, such as crown moldings, which are to be fitted to comers of various sizes, depending on ceiling heights and the requirement of how much of the corners are desired to be decorated, manufactured crown moldings produced in long pieces must be cut to the desired lengths. In cutting the manufactured crown moldings, two basic angles must be cut so that one end of the crown molding will conform to the ceiling, and the other end thereof will conform to the adjoining wall.
In preparing a crown molding, it is necessary to make two basic angle cuts, one on each end of the crown molding. The angle cut is typically about 52° and about 38° at the respective ends of the crown molding. The so-cut crown molding, when placed against a ceiling and an adjoining wall which form a 90° angle between them, will form the hypotenuse of the triangle. In addition to the two basic angle cuts in a crown molding, it is necessary to make two bevel cuts at the ends of the crown molding by cutting across the grain of the crown molding with the miter blade angled to the crown molding. In making a compound miter cut at each end of the crown molding, a miter angle and a bevel angle is used at the same time.
To make the angle cut and the bevel cut simultaneously with a hand-held power saw, the prior art has provided a guide for cutting compound miters in crown moldings with a circular saw, such as disclosed in U.S. Pat. No. 4,907,482. While the device is inexpensive as compared to motorized miter boxes, it does has some drawbacks associated with hand-held power saws, such as handling difficulties of the power saws in a safe manner.
Motorized miter boxes have been developed for cutting workpieces at various angles and are being marketed by several manufacturers. Such motorized miter boxes typically comprise a work table for supporting the workpieces to be cut, a fence against which the workpieces are registered to hold the same during the cutting process, and a power saw reciprocable with respect to the work table to cut the workpieces supported by the work table. The work table and saw are angularly adjustable with respect to the fence so that the cut can be made at a desired angle. The motorized miter boxes enable the user to cut simple miters wherein the workpieces lay flat against the table and the fence; they also enable the user to cut compound miters wherein the workpiece is cut at an angle to its longitudinal axes while no major planar surface of the workpiece is parallel to either the work table or the fence. When compound miters are cut, filler blocks are used to provide a support surface oriented at an acute angle to both the work table and the fence. The filler blocks are typically secured to the work table or the fence by removable means, such as bolts and screws.
The prior art has further provided a miter box attachment for cutting crown and frame moldings with a miter saw as disclosed in U.S. Pat. No. 4,875,399. The reference uses a pair of jigs slidably mounted on opposite lateral edges on the table to be movable toward and away from the fence. The jig also includes a registration block which supports a workpiece in a cocked position against the fence for cutting of a compound miter.
In the prior art devices using a miter saw, filler blocks are used to hold and support the workpiece in place during the cutting process. The filler blocks are attached to the fence or worktable of the miter saw by clamps or other removable means. In U.S. Pat. No. 4,875,399 the filler blocks are replaced by a pair of slidably adjustable jigs to allow the workpiece to be moved toward or away from the fence of the miter saw. While the use of these means help to accomplish the desired result, the present invention accomplishes the desired result without the use of these implements by the provision of a simple crown molding holder used in conjunction with the miter saw.
SUMMARY OF THE INVENTION
According to the present invention, a workpiece holder, such as a crown molding holder, is provided for use in combination with a motorized miter box for cutting miter joints which require a simultaneous bevel and miter cutting operation.
The motorized box comprises:
a horizontal work table with a planar surface for supporting a workpiece;
a vertical fence extending from the work table and forming a 90° angle therewith to provide a registration surface for the workpiece; and
a miter saw having a reciprocating arm with a tiltable cutting blade supported on the work table and registered against the vertical fence.
The workpiece holder is positioned on the horizontal work table and against the vertical fence on the worktable, the workpiece holder comprising:
a horizontal bottom plate slidably conforming to the planar surface of the work table;
a vertical side plate slidably conforming to the vertical fence and projecting away from the horizontal bottom plate enclosing a 90° angle therewith, said horizontal bottom plate and said vertical side plate being integral with each other.
In order to securely hold a workpiece therein: the horizontal bottom plate of the workpiece holder is provided with a vertical integral rim extending longitudinally along the length of the horizontal bottom plate; and the vertical side plate is provided with a horizontal integral rim extending longitudinally along the length of the vertical side plate.
The workpiece holder is preferably made of 20 gauge galvanized steel which is magnetized to facilitate holding the workpiece holder against the fence of the miter table. The workpiece holder may also be made of aluminum and synthetic polymeric materials.
The workpiece holder may also be equipped with double-face pressure sensitive tape on the horizontal and vertical plates thereof to facilitate holding of the workpiece holder on the work table and against the fence of the miter box.
In use, the workpiece, such as a crown molding, is inserted into the work piece holder upside down with a portion of the molding intended to be cut extending away from and overhanging the workpiece holder so that the saw blade has no direct contact with the workpiece holder during the cutting process.
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McGrory Roseanne C.
McGrory, Sr. John M.
Balogh Imre
Dexter Clark F.
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