This patent application is related to a copending U.S. patent application Ser. No. 08/499,339, filed Jul. 7, 1995, entitled “Adjustable Fence For Compound Miter Saw”, the disclosure of which is hereby incorporated by reference herein.
The present invention relates primarily to power chop-type saws, miter saws, compound miter saws or other power operated equipment or machinery utilizing a blade or other cutter for performing working operations on workpieces composed of wood, metal, plastic or other materials. More particularly, the present invention seeks to achieve various improvements in blade guard mechanisms for such power operated equipment, typically having a lower movable guard pivotally movable relative to a fixed upper guard between “closed” and “open” positions as the blade is pivotally moved between non-cutting and cutting positions. Preferred forms of the present invention also relate to improvements in blade or cutter arbor shaft covers and to blade or cutter calipers in conjunction with the guard mechanism, as well as to a blade or cutter hold-down arrangement for preventing operation of the saw when in a locked-down state. Still another preferred form of the invention includes advantageous improvements in the operator handle position, orientation and configurations that optimize the user's comfort and control of the blade or cutter when performing a wide variety of cutting operations.
Saws and other apparatuses designed for cutting or performing other working operations on a workpiece typically include mechanisms for setting the saw blade or cutting tool in selected angular relationships with the workpiece when performing various cutting operations. Examples include chop-type compound miter saws adapted for allowing the user to selectively set the saw blade at any of a number of positions or modes for square cutting, miter cutting, bevel cutting, or even compound miter cutting in which combination miter angle and bevel angle cutting operations are performed on the workpiece. In addition, some operations, such as dado cutting, groove cutting, or shaping operations, for example, require the use of saw blades or other cutting or working devices of different shapes or sizes to be substituted for one another in order to perform the desired operation on the workpiece. In these instances, the saw or cutting device must be capable of cross-cutting or sliding movement of the blade or cutting tool in lieu of, or in addition to, chop-type engagement with the workpiece.
In order to allow for the setting of miter and bevel angles, the saw blade, cutter or other working device is angularly adjustable with respect to both a horizontal base and a vertical fence against which the workpiece is positioned. The miter adjustment allows the saw blade, cutter or other working device to be angularly positioned with respect to the vertical fence while maintaining perpendicularity with the horizontal base. The bevel adjustment allows the saw blade, cutter or other working device to be angularly positioned with respect to the horizontal base while maintaining perpendicularity with the vertical fence. Various combinations of miter angles and bevel angles are accomplished by simultaneously adjusting the angularity of the blade with respect to both the horizontal base and the vertical fence.
In any of these cutting operations whether they are performed on chop-type, cross-cut, or combination type devices, a blade guard mechanism must be capable of exposing a sufficient portion of the blade to perform the desired cutting operation, while at the same time adequately protecting the operator during cutting and when the blade is in an at-rest position. Such a guard mechanism also should preferably protect the guard from damage in the event of a bent or deflected blade or cutter during such operations, should prevent the blade or cutter from vibrating loose from or on its arbor shaft during such operations, and should allow for maximum user comfort and control when performing such operations. Preferably, undesired operation of the saw or other such device should be prevented when in a storage or inoperative state.
Unfortunately, many conventional devices have proved to be deficient in meeting some or all of these objectives, or have required burdensome multiplicities of parts or components in order to achieve them. Thus, many of such conventional devices have also often been found to be heavy and overly complex, difficult and expensive to design, manufacture and maintain, as well as requiring large spaces in which to operate them. In some cases, meeting these objectives has also resulted in unduly limiting cutting capacities.
In accordance with the present invention, a blade or cutter guard mechanism preferably includes an upper guard that is fixed relative to a drive assembly for the arbor shaft of the blade or cutter and a lower guard that is pivotally movable relative to the fixed upper guard. Preferably, a guard-actuating linkage assembly includes a first link having an inner end pivotally interconnected with a housing assembly upon which the drive assembly is pivotally mounted in order to move the blade and drive assembly into engagement with the workpiece. An opposite intermediate end of the first link is pivotally interconnected with an intermediate end of yet another, second link whose opposite outer end is pivotally and drivingly interconnected with the movable guard. An intermediate roller or roller assembly is rotatably interconnected with the interconnected intermediate ends of the links and is engageable with a cam surface at a fixed location formed on the drive assembly and thus fixed relative to the fixed guard. The shape and position of the cam surfaces are pre-designed to control the rate of movement of movable guard as the saw blade or cutter is moved between non-cutting and cutting positions. In a preferred form of this guard arrangement, the moveable guard can be manually moved for overriding pivotal movement irrespectively and independently of the position of the blade and drive assembly relative to the workpiece.
A return spring can be advantageously included in the guard linkage assembly for resiliently biasing the movable guard toward a normally closed position covering a maximum portion of the cutting periphery of the blade or cutter. Such return spring is preferably a torsional coil spring with one anchoring end or leg interconnected with the fixed guard or drive assembly (at a fixed location thereon) and an opposite end or leg interconnected with the movable guard (also at a fixed location thereon). An off-center spring enclosure, which is radially offset relative to the arbor shaft, is preferably included for restricting radial expansion of the torsional spring to directions away from the workpiece (on opposite sides of the arbor shaft from the workpiece) in order to maximize the workpiece cutting depth capacity of the saw blade or cutter.
Another optional but preferred feature of the invention is an arbor shaft cover that is pivotally interconnected with the fixed guard and that substantially prevents or minimizes any tendency of the arbor shaft nut, screw or other blade-securing fastener to work loose on, or free of, the arbor shaft. Such arbor cover can be pivoted out of the way to allow blade removal or blade changing by way of a releasable cover retaining fastener at one end of the pivotal cover, with such retaining fastener also optionally being configured to extend axially inside the fixed guard when tightened so as to act as one of a pair of blade calipers axially spaced from opposite sides of the blade or cutter. Such calipers thereby prevent or substantially minimize damage to the fixed guard in the event of a bent or deflected blade or cutter.
A hold-down strap member can also be included and be can pivotally interconnected with the saw's base for movement between a storage position and a hold-down position in releasable engagement with the saw's drive assembly in order to releasably secure the drive assembly in a lowered storage position relative to the base.
Also, the operator handle of the saw preferably includes a horizontally extending gripping portion that is generally centered laterally with respect to the plane of the blade or cutter. This contributes advantageously to workpiece visibility, ease of use, and operator control of the saw or other cutting device so equipped.
Other advantages, objects and features of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims and accompanying drawings.
a through 9c schematically illustrate the resilient flexing of the preferred torsional lower guard return spring at various movable lower guard positions for the preferred guard mechanism of
a through 10d are diagrammatic views, with parts removed or broken away, to schematically illustrate the operation of the linkage arrangement for controlling the lower guard movement between workpiece non-engagement and engagement positions for the blade or cutter of the saw illustrated in
a and 13b are partial cross-sectional views, illustrating a blade caliper arrangement incorporated into the arbor shaft cover arrangement.
a and 14b are partial perspective views of a hold-down arrangement for the preferred sliding compound miter saw depicted in
b depict exemplary embodiments of a sliding compound miter saw according to the present invention, which is shown in the drawings merely for purposes of illustration. One skilled in the art will readily recognize, from the following description, taken in conjunction with the accompanying drawings and claims, that the principles of the invention are equally applicable to compound miter saws and/or chop saws of types other than that depicted in the drawings. Similarly, one skilled in the art will readily recognize that the principles of the invention may also be applicable to other workpiece cutting, forming or shaping devices.
In
The housing assembly 16 is secured to the table assembly 14 such that it can be pivoted with respect to the table assembly in order to provide adjustment for bevel cutting of the workpiece 13. The bevel pivoting of the housing assembly 16 changes the angle of the saw blade 18 relative to the table assembly 14 but maintains the perpendicularity of the saw blade 18 with respect to the fence assembly 26. A locking mechanism 30 can be activated in order to lock the housing assembly 16 to table assembly 14 at a desired bevel-cutting position. As can be appreciated by one skilled in the art, the adjustments for mitering and beveling can be performed separately or simultaneously in order to perform a compound miter and bevel cut.
The housing assembly 16 also includes a support housing or assembly 32, which mounts a pair of support arms 34 for sliding movement with respect to the remainder of the housing assembly 16. The saw blade 18, the blade guard 20, the motor 22 and the handle 24 are all mounted to a drive assembly 36, which is pivotally interconnected with the support arms 34 and thus the support assembly 32. The pivoting of the drive assembly 36 downwardly towards the table assembly 14 operates to bring the saw blade 18 into a workpiece-engaging position and simultaneously open the blade guard 20 (as is described in more detail below) in order to cut a workpiece which is supported by the table assembly and the fence assembly 26. The sliding movement of the support arms 34 relative to the housing 16 permits the drive assembly 36 and thus the saw blade 18 to be pulled or pushed through the workpiece.
Referring to
The blade guard assembly 20 also includes a linkage assembly 46, which functions to pivot the movable guard 42 between its open and closed positions as the drive assembly 36 is pivoted by the operator about a pivot pin 38 (
The linkage assembly 46 includes an inner link 48 having an inner end 56 pivotally interconnected with the support housing 32 at a fixed location thereon. The linkage assembly 46 also includes an outer link 50 having an outer end 58 pivotally interconnected with the movable guard 42, also at a fixed location thereon. The opposite intermediate ends of the inner link 48 and the outer link 50 are pivotally interconnected with each other and with an intermediate rotatable pivot and roller assembly 52. The roller assembly 52 is adapted to engage a cam surface 54 formed on the drive housing assembly 36 (and thus fixed relative to the fixed upper guard) for purposes of controlling the closing and opening movement of the movable guard 42 as the drive housing 36 and the blade 18 are raised and lowered, respectively, out of and into cutting engagement with the workpiece 13. The shape and position of the cam surface 54 are carefully chosen in order to determine and select the amount and rate of opening movement of the lower guard 42. These raised and lowered positions are diagrammatically illustrated in
Because the intermediate roller assembly 52 is free to move, along with the intermediate ends of the inner link 48 and the outer link 50, along the cam surface 54, the location of the intermediate roller assembly 52 is not fixed or restrained with respect to either the fixed upper guard 40 (which is fixed with respect to the drive assembly 36) or the movable lower guard 42. Thus, primarily for ease of blade changing, replacement or maintenance, the movable lower guard 42 can be manually pivoted by the user about the arbor shaft axis 45 in an overriding manner, independent and irrespective of the pivotal position of the drive assembly 36 and the blade 18. Two examples of this independent overriding movement of the movable lower guard 42 are shown in
Referring primarily to
Because the preferred return spring 70 is a torsional coil spring, it radially expands and contracts relative to the arbor shaft axis 45 as the movable guard 42 is pivoted about a lower guard axis 47 (see
As is diagrammatically illustrated in
a diagrammatically depicts the movable lower guard 42 in its “closed” position, with the return spring 70 in its preloaded, maximum radially-expanded condition.
Referring to
Referring to
Finally, the saw 10 can optionally be equipped with a hold-down member or strap 90, illustrated in
The strap 90 can be releasably retained in its storage position using any of a wide variety of well-known releasable retention arrangements. However, one arrangement currently contemplated is a strap 90 that is resiliently deflectable laterally, with the strap having a resilient bias in the rightward lateral direction as viewed in
The foregoing discussion discloses and describes merely exemplary embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications, and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
This is a division of U.S. patent application Ser. No. 08/974,093, filed Nov. 19, 1997 now U.S. Pat. No. 6,182,548, which is a divisional of application Ser. No. 08/541,667, filed Oct. 10, 1995, now U.S. Pat. No. 5,724,875, issued Mar. 10, 1998.
Number | Name | Date | Kind |
---|---|---|---|
679167 | Garding | Jul 1901 | A |
852964 | Koegel | May 1907 | A |
1314291 | Wallace | Aug 1919 | A |
1464924 | Drummond | Aug 1923 | A |
1589970 | Jones | Jun 1926 | A |
1646589 | Meek et al. | Oct 1927 | A |
2106321 | Guertin | Jan 1938 | A |
2765824 | Hartmann et al. | Oct 1956 | A |
2861607 | Emmons | Nov 1958 | A |
3721141 | Frostad | Mar 1973 | A |
3821918 | Niehaus et al. | Jul 1974 | A |
3998121 | Bennett | Dec 1976 | A |
4028975 | Bennett | Jun 1977 | A |
4176571 | Batson | Dec 1979 | A |
4318324 | Hall et al. | Mar 1982 | A |
4343213 | Drixler | Aug 1982 | A |
4581966 | Kaiser et al. | Apr 1986 | A |
4774866 | Dehari et al. | Oct 1988 | A |
4799416 | Kumasaka et al. | Jan 1989 | A |
4805504 | Fushiya et al. | Feb 1989 | A |
4869142 | Sato et al. | Sep 1989 | A |
4892022 | Cotton et al. | Jan 1990 | A |
4934233 | Brundage et al. | Jun 1990 | A |
4951540 | Cross et al. | Aug 1990 | A |
5020406 | Sasaki et al. | Jun 1991 | A |
5046390 | Sasaki | Sep 1991 | A |
5054352 | Fushiya et al. | Oct 1991 | A |
5060548 | Sato et al. | Oct 1991 | A |
5074179 | Omi | Dec 1991 | A |
5146825 | Dehari | Sep 1992 | A |
5203245 | Terpstra | Apr 1993 | A |
D346173 | Price | Apr 1994 | S |
5347902 | Brickner et al. | Sep 1994 | A |
5370025 | Itzov | Dec 1994 | A |
5524516 | Sasaki et al. | Jun 1996 | A |
5579584 | Hoffman | Dec 1996 | A |
5609085 | Chang | Mar 1997 | A |
5623860 | Schoene et al. | Apr 1997 | A |
5638731 | Garuglieri | Jun 1997 | A |
5724875 | Meredith et al. | Mar 1998 | A |
5755148 | Stumpf et al. | May 1998 | A |
5937720 | Itzov | Aug 1999 | A |
5957021 | Meredith et al. | Sep 1999 | A |
6182548 | Meredith et al. | Feb 2001 | B1 |
6425309 | Stumpf et al. | Jul 2002 | B1 |
6431042 | Brault et al. | Aug 2002 | B1 |
Number | Date | Country |
---|---|---|
0 538 066 | Apr 1993 | EP |
0 538 066 | Apr 1993 | EP |
0 570 904 | Nov 1993 | EP |
0 633 106 | Jan 1995 | EP |
0 633 106 | Nov 1995 | EP |
1777384 | Jul 1976 | GB |
2 304 075 | Mar 1997 | GB |
6-59008 | Aug 1994 | JP |
484 996 | Sep 1975 | SU |
WO 9313919 | Jul 1993 | WO |
Number | Date | Country | |
---|---|---|---|
Parent | 08974093 | Nov 1997 | US |
Child | 09698920 | US | |
Parent | 08541667 | Oct 1995 | US |
Child | 08974093 | US |