The present invention generally relates to power hand tools and, more particularly, to plunge-type routers.
Plunge-type routers are well known and commonly used to cut grooves, edges and a variety of shapes in work pieces made of wood and other materials. The shapes are determined by the kind and shape of router bits used, the depth of cut of the bit and the path of travel by the router bit relative to the work piece. A plunge router is constructed to move the router bit toward and away from the work piece when the router is being operated in a freehand manner. It can often also be mounted to a router table so that the router bit extends through an opening in the top of the table. The depth of cut of the router bit is typically determined by an adjustable depth stop system which may or may not include means for locking the router in its plunged position.
During freehand operation, the plunge router may be supported on the work piece with the bit retracted and placed in the desired location so that when it is turned on and plunged downwardly, the router bit advances into the work piece and the operator then moves it relative to the work piece to complete the desired routing operation. To do the plunging operation, the operator must exert a downward force on the motor housing assembly, generally by pressing on attached handles to move the router bit into contact with the work piece. The motor housing assembly is typically biased to automatically retract the router bit from the work piece when the downward force imparted by the operator is removed.
Plunge routers generally include a plunge adjustment mechanism that enables the operator to control the distance the router bit can move toward the work piece and thereby determine its depth of cut. As is well known to those who have used plunge type routers, the adjustment of the stop system must be carefully done to achieve the desired depth of cut. Because the type and size of various router bits are very different, it is prudent if not necessary to recalibrate or reset the adjustment means after any manipulation of the router bit to insure that it has been accurately set to achieve the desired depth of cut. There are many other devices that attempt to accurately set the depth adjustable stop to provide an accurate depth of cut, including adjustable rods, scales with indicators, micrometer type adjusters and other systems. Such adjustable stop mechanisms in the prior art are generally hand manipulated and some may have a printed scale or other indicia located on the mechanism for use in providing a specified depth of cut. However, it is still necessary for users to carefully measure the depth of cut in one way or another to insure that the desired cut will be made. In this regard, it is often common practice to perform a test cut on a scrap piece and actually measure the result and to iteratively adjust the stop mechanism until the proper result is achieved.
A plunge-type router is disclosed which is useful for either freehand or router table mounted operation. The router has a base and a motor housing assembly with the base being adjustable relative to the motor housing assembly and operates in a conventional plunge router operation, but has an depth rod adjusting and measuring mechanism that includes an electronic measuring system with a digital display and control functionality that enables a user to accurately measure the position of a depth rod and thereby accurately set a depth of cut value which is displayed on a digital readout.
Alternate embodiments include motorized depth adjusting mechanisms to adjust the depth rod position and thereby adjust the depth of cut of the router during operation, as well as an embodiment that is a hybrid router which has a removable motor assembly that can be coupled to a plunge-type router base.
A preferred embodiment of the present invention is shown in
The housing assembly is generally biased in the upward direction so that it will automatically raise itself relative to the base 22 when the locking mechanism 34 is released. During operation, when a user releases the locking mechanism 34 and forces the handles downwardly, the router bit 36 will engage a work surface. The depth of the cut that may be made is a function of the amount of downward movement by the housing assembly. To accurately cut at a desired depth, a depth rod 40 which is part of a depth rod adjustment mechanism indicated generally at 42 can be vertically adjusted relative to the base 22. A rotatable turret 44 may be provided to assist in providing different predetermined depth of cut set positions.
The depth rod adjusting mechanism 42 includes a locking lever 46 which has a threaded screw that engages a threaded opening in a boss 48. The end of the screw is capable of contacting the side of the depth rod 40 to secure its position when the locking lever 46 is rotated into engagement with it.
Referring to
To set a depth of cut, the locking lever 46 is first loosened so that the depth rod 40 can be adjusted. The operator then presses down on the handle so that the router bit 36 is brought into contact with the work surface and the lock 34 is then applied to hold the bit in contact with the work surface. The user then adjusts the knob 50 to bring the depth rod 40 into contact with one of the five surfaces of the turret 44. The user then uses the locking lever 46 to lock the depth rod 40 in place. The operator then depresses the pushbutton 20 to reset or zero the display. After that has been done, the user unlocks the locking lever 46 so that the depth rod can be moved, and he then adjusts the knob 50 to raise the depth rod 40 while watching the digital display 16 until the desired plunge depth is indicated on the display, whereupon the user then tightens the locking lever 46 to lock the depth rod 40 in place. The plunge depth has then been accurately set.
This embodiment is adapted to be mounted to a router table which inverts the router so that the router bit will extend through an opening and engage the underside of a work piece. When used in such a router table, the rod is locked to the turret 44 and the adjusting knob 50 acts to raise and lower the motor housing and thereby adjust the protrusion height of the bit above the table surface. The depth rod can be adjusted, the display zeroed and the depth of cut determined by manipulating the knob 50 while viewing the display.
A second and third embodiment of the router is shown in
With regard to the second embodiment shown in
In this second embodiment, the router is adapted to be mounted to a router table which inverts the router so that the router bit will extend through an opening and engage the underside of a work piece as it is being manipulated on the router table. By locking the depth rod 70 into the keyhole 82, activation of the motor 64 will physically move the housing assembly 12 relative to the base 22. If the router is mounted in a router table, the display 16 can be inverted so that a user can read the depth of cut without reading it upside down.
A third embodiment of the router employs a motor 90 that drives a gear mechanism 92 that in turn drives a threaded output shaft 94 that engages the interior threads of a depth rod 96 that has an end portion 98 for engaging the turret 44. The motor 90, and gear mechanism 92 are mounted in the housing in a fixed position. While not shown, an outwardly extending anti-rotation pin is or the like is attached to the depth rod 96 and is configured to ride in a vertical recess or slot to prevent the depth rod from rotating when the shaft 94 is rotated. This assures that rotation of the output shaft 94 will cause the depth rod to move vertically relative to the housing 12. Pushbuttons 84 and 86 also control the operation of the motor to either raise or lower the depth rod 94 as in the second embodiment of the router. The end portion 98 of the depth rod has the same configuration as in the second embodiment so that the locking lever 80 can hold the depth rod in the same manner as in the second embodiment. This similarly enables the router to be mounted to a router table and have the depth of cut be accurately determined in the same manner as described with respect to the second embodiment. It should be appreciated that the embodiment of
In either of the motorized embodiments of
A fourth embodiment is shown in
A fifth embodiment is shown in FIG. 7 and comprises a hybrid router, indicated generally at 110, that has a plunge base assembly, indicated generally at 112, in which a motor assembly 114 can be attached. As shown, the motor assembly 114 is generally cylindrically shaped and can be inserted into a mounting portion 116 that has a cylindrical opening. The motor assembly has an output shaft to which a collet assembly 118 is preferably attached for securing a router bit or other tool to the router during operation attachment. The plunge base assembly 112 has a vertically oriented housing 120 in which a depth rod adjusting mechanism is contained, with the mechanism being similar to the embodiment of
With regard to the display 16 and referring to
The display is one of a liquid crystal display or a light emitting diode display.
The display 16 is preferably designed to turn on with the same units that existed before the router was turned off and also operates as follows. If the display button 18 is pressed for less than ½ second, it may temporarily change the display and then return to the default after two seconds. If the display button is pressed for longer than ½ second, the display may cycle between speed adjustment and display, depth of cut as well as inverted (i.e., upside down) speed and inverted depth of cut. The zero/scale button when pressed for less than ½ second resets the depth of cut to zero and if it is held for more than ½ second, the scale will change from metric to inches or vice versa. When the change is made, the appropriate mm or inch icon will be switched on and off. The display buttons can also be designed operate in a non time dependent way. In this type of display, the display button cycles the display between displaying speed, depth of cut in English or metric numbers and depth of cut using inverted English or Metric numbers. The zero/scale button would act to zero the measurement.
When in the speed adjustment and display mode, the switches 84 and 86 can be used to adjust the operating speed of the main router drive motor. While the display 16 shown in the embodiment of
With regard to the measurements that are displayed, the appropriate decimal point will be illuminated depending upon whether the display is displaying upright or inverted when English or metric is used. If fractions are used, then the appropriate slash will also be illuminated. The measurement is right justified according to whether the decimal point or slash is used.
While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.
Various features of the invention are set forth in the following claims.
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Number | Date | Country | |
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20050079025 A1 | Apr 2005 | US |