Woodworking – Shaping machine – Hand tool
Reexamination Certificate
1998-11-16
2001-02-06
Bray, W. Donald (Department: 3725)
Woodworking
Shaping machine
Hand tool
C144S134300, C144S137000, C200S043170, C318S273000, C318S275000, C409S182000
Reexamination Certificate
active
06182723
ABSTRACT:
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention is directed to router improvements. These improvements include a switching system which is part of a router handle and which operates the router motor by connecting it to an external electrical power source. In a preferred embodiment, the present switching system comprises the use of a locking lever and trigger in combination to activate the motor, to hold the trigger in a locked-on position to maintain the connection of electrical power to the motor, and to lock the movement of the trigger from occurring before an operator attempts to engage the motor. The switching system may also be combined with a preferred router handle shape in order to make the long term operation of the router and its switching comfortable with extended use.
A further improvement relates to a router chuck and collet mounting system. In a preferred embodiment, the present mounting system comprises mating a top face of a router chuck with the lower surface of an inner race of an armature shaft bearing and mating an inner diameter of the chuck with an outer diameter of the armature shaft to align the chuck with the shaft. Additionally, a cavity through the chuck may be used to accept a router bit shank so that it extends up into a lower end of the shaft in order to permit the shank to extend upward, closer to the armature shaft bearing. This arrangement reduces router bit run-out.
A further improvement relates to a plunge router locking system. The locking system comprises a locking arm lever coupled to a threaded member arm which engages a plunge guide post to hold the router motor housing at a desired height above the router base when the locking arm member is in the locked position. When the locking arm member is moved into an unlocked position, the motor housing can move up and down the plunge guide post, where the motor housing is opposed by a bias system comprising a compression spring to prevent the motor housing from free-falling into the router base. Additionally, the locking arm lever can be held in the unlocked position with the use of a mating coupling member attached to the motor housing in order to keep the plunge locking system in an unlocked position.
A further improvement relates to a switchable router brake system. The switchable brake system permits a motor brake to be selectably engaged to operate when the router motor is turned off. When engaged, the motor brake, which comprises a brake resistor being placed electrically across the motor windings, causes the router motor to stop rotating almost immediately. This feature, however, is not always desired; the switchable brake system permits the operator to engage the use of the brake only when desired, thus providing the option to selectively eliminate jerking caused electric brake torque induced in the router when the brake engages.
A further improvement relates to a plunge router depth stop system. The depth stop system comprises a depth stop rod contained within a restraining collar coupled to the router housing. The depth stop rod is configured both to rotate at a fixed height above the router base and to slide up and down within the collar in order to adjust its height above the base. At an upper end of the depth stop rod, a turret knob permits an operator to rotate the rod within the collar. At the other end of the rod, a protrusion portion selection member is located to engage selectively one of a plurality of step-wise rising depth stop position surfaces located on the router base. When the protrusion portion selection member is aligned vertically above one of the depth stop position surfaces, the motor housing will plunge until the protrusion portion selection member engages the depth stop position. The operator sets the depth stop height by placing the depth stop rod at the desired height and tightening a restraining collar. Once configured in this position, the motor housing can be repeatably plunged to a desired position. The operator can selectively step the depth downward by keeping the depth stop rod at the desired position while rotating the rod to align the protrusion portion selection member to another depth stop position having a different depth stop height.
A further improvement relates to ergonomic router handles. The preferred router handles are generally elliptical in shape and have one end narrower than the other end. The handles are shaped to provide an operator an infinite number of angles to which the operator's hand may effectively grip the handles. Additionally the handles provide an outer surface which provides a flat tactile grip area The combination of these elements, along with the shape and location of the preferred trigger and locking arm switch used to activate the preferred router, provides an operator, while operating the router, with the ability to find and use a handle-holding position which is comfortable for the individual user for holding the handles.
A further improvement relates to a sub-base alignment system. In a preferred embodiment, the alignment system comprises a plurality of raised bosses which are located on the sub-base at known locations and which engage a plurality of recessed cavities in the router base. Alternatively, the raised bosses may be placed on the router base and the cavities may be located in the sub-base, or a combination of boss and cavity locations may be used. The router base is positioned at a known locations relative to the center of rotation of the router bit. For example, in the plunge router shown, the base is coupled to plunge guide posts, which themselves are coupled to the motor housing at known locations. The coupling of the raised bosses with the recessed cavities places the sub-base at a known position relative to the router base. In such a configuration, the outer edge of the sub-base, which may be used to guide the router when making a cut, is held at a known position relative to the center of rotation of the router chuck, thus enabling the precise guidance of the router relative to a guide member.
These and various other advantages and features of novelty which characterize router improvements are pointed out with particularity in the claims which are annexed hereto and which form a part hereof. However, for a better understanding of the improvements, their advantages, and the objects obtained by use of these improvements, reference should be made to the drawings which form a further part hereof, and to accompanying descriptions, in which there are illustrated and described specific examples of the improvements.
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Banduch Leslie J.
Bosten Donald R.
Cooper Randy G.
McNeal, Jr. Waymon L.
Stolzer James T.
Bray W. Donald
Merchant & Gould P.C.
Porter-Cable Corporation
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