Dust collection system for compound miter saw

Information

  • Patent Grant
  • 6431040
  • Patent Number
    6,431,040
  • Date Filed
    Monday, March 13, 2000
    24 years ago
  • Date Issued
    Tuesday, August 13, 2002
    21 years ago
Abstract
A dust or chip collection and diversion system is provided for a device having a cutting tool for performing a working operation on a workpiece. The position and orientation of the dust-receiving or dust-collecting opening remains constant with respect to the cutting tool regardless of the position or configuration of the device, the device having a movable blade or other cutting tool, thus greatly enhancing the dust collection effectiveness in any of a number of operational configurations. Such position and orientation of the dust-receiving opening is also independent of the movement or position of any adjustable or movable guard or workpiece-supporting fence.
Description




BACKGROUND AND SUMMARY OF THE INVENTION




The present invention relates generally to dust or chip collection systems for saws or other power operated equipment or machinery. More particularly, the invention relates to such dust or chip collection systems with the dust collector being disposed on a movable portion of the saw or other such equipment in order to maintain proper dust-collecting alignment with a movable saw blade or other work-performing device while performing various operations on a workpiece.




Saws and other apparatuses designed for cutting or performing other working operations on a workpiece frequently require a saw blade, cutter, or other such work-performing device that is movable to a number of different positions or orientations for performing various operations. Examples of such equipment include compound miter saws, which allow the user to selectively move the saw blade into any of a number or positions or modes for square cutting, for miter cutting, for bevel cutting, or for compound cutting where a combination miter and bevel are cut. In addition, some operations, such as shaping or dado cutting operations, for example, require the use of saw blades or other cutting devices of different shapes or sizes to be substituted for one another in order to perform the desired operation on the workpiece, whether the workpiece is composed of wood, plastic, metal, or other materials. In most examples of such equipment, it is highly desirable to provide a dust collection system for diverting dust and chips away from the user.




In order to accommodate these widely varied working operations, dust collection ducts, or openings are frequently disposed on an adjustable guard so as to be at least partially adjustable for various operations, or on a fence in order to accommodate the varied positions or orientations of the blade or other cutter. If such dust collector adjustability, by way of adjustment of the guard, were not provided, a substantial loss of dust-collecting effectiveness would result, or a very large dust collection opening would have to be provided in order to accommodate the widely varying range of movement, position, or size of the saw blade, cutter, or other working device. Such collection ducts or openings on guards or fences have been found to be relatively ineffective in many of their adjusted positions, and such large collection openings have been found to be cumbersome and disadvantageous because of the space occupied by them.




In an attempt to address the above-discussed problems, a variety of other dust collection arrangements have previously been provided. However, many of such prior arrangements have suffered the same or other disadvantages, including difficulty in maintaining proper alignment between the dust collection duct or opening and the saw blade or other cutter, inconvenience and interference when performing operations on large or odd-shaped workpieces, the possibility of inadvertently misplacing separate dust collection components, lack of adequate dust collection, or other similar short-comings. Thus, the need has arisen for a dust collection system for compound miter saws, or other power equipment with movable or adjustable blades or cutters, which overcomes these disadvantages, as well as providing greater dust-collection effectiveness, improved ease of operation, economy in manufacturing, and other advantages that will become readily apparent to those skilled in the art from the discussion below.




In accordance with the present invention, an improved dust collection system for a saw or other device having a movable blade or cutting tool is provided. The dust collection system is spaced away from the saw blade or other cutting tool, is separate from any blade or cutter guard, and includes a dust-receiving opening that is at a fixed location relative to the movable blade or cutting tool and movable therewith. Preferably, the dust-receiving opening has an orientation relative to the blade or cutting tool that is aligned with a line that extends between the opening and the blade or cutting tool, with such line extending along a tangent to the rotation of the blade or cutting tool, and with such tangent preferably being at a location on the blade or cutting tool that engages the workpiece when the blade or cutting tool is moved to a workpiece-engaging position. Such dust collection opening orientation thus remains essentially constant during movement of the blade or cutting tool and is independent of any adjustment of the guard.




In preferred embodiments of the present invention for compound miter saws, for example, the dust-receiving opening is disposed at the open end of a dust duct that is interconnected with a pivot mechanism that is adapted for pivotally moving the saw blade into and out of engagement with a workpiece and for pivotally moving the saw blade among various cutting configurations. Such preferred dust duct is pivotally movable with a pivot arm and is preferably disposed in a bifurcated portion of the pivot arm in a space between a pair of spaced-apart legs. The dust duct is adapted for conveying dust or chips away from the saw and the user and can be connected in dust-conveying communication with a dust collection receptacle, either with or without powered dust extraction or dust-conveying vacuum equipment.




Additional objects, advantages, and features of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a front perspective view of an exemplary compound miter saw featuring a dust collection system according to the present invention.





FIG. 2

is a front elevational view of the compound miter saw of FIG.


1


.





FIG. 3

is a rear elevational view of the compound miter saw of

FIGS. 1 and 2

.





FIG. 4

is a left end elevational view of the compound miter saw of

FIGS. 1 through 3

, with portions cut away to illustrate the dust-receiving duct of the present invention.





FIG. 5

is a schematic elevational view, diagrammatically illustrating the exemplary compound miter saw in use for cutting a relatively thick workpiece.





FIG. 6

is a schematic top plan view, diagrammatically illustrating the exemplary compound miter saw in use for performing a miter-cutting operation.





FIG. 7

is a schematic elevational view, similar to that of

FIG. 6

, but diagrammatically illustrating a bevel-cutting operation.





FIG. 8

is an elevational view illustrating the optional inclusion of a dust is collection receptacle in the exemplary dust collection system of the present invention.





FIG. 9

is a cross-sectional detail view of a preferred dust collection duct according to the invention.





FIG. 10

is a top detail view of a preferred dust collection duct according to the invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS





FIGS. 1 through 10

illustrate an exemplary compound miter saw having a dust collection system according to the present invention, shown 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 or other saws of types other than that shown for purposes of illustration in the drawings. Similarly, one skilled in the art will readily recognize that the principles of a dust collection system according to the invention are also applicable to other types of powered, or even unpowered, equipment for performing an operation on a workpiece. Such other types of equipment include so-called “chop” saws, dado saws, spindle shapers, spindle sanders, or other types of powered or unpowered devices that require movable blades or cutters in order or to perform various different workpiece working operations.




Referring primarily to

FIGS. 1 through 4

, an exemplary compound miter saw


10


typically has a base assembly


12


, including a table assembly


13


, which is preferably rotatable in order to accommodate the various cutting modes discussed below. The saw


10


also includes a saw blade


14


, at least partially enclosed by a blade guard


16


and driven by a motor


17


, and a handle


18


, which allows the operator to move the saw blade


14


and the blade guard


16


from a clear position free of a workpiece


11


(

FIG. 4

) to a cutting position with the saw blade


14


in cutting engagement with the workpiece


11


.




As is conventional in this type of equipment, a fence assembly, indicated generally by reference numeral


20


, is interconnected with the base assembly


12


and extends laterally across the table assembly


13


, against which the workpiece


11


is positioned and supported for performing a cutting operation thereon. The illustrated fence assembly


20


includes a fixed fence portion


22


and a movable fence portion


24


, with the fixed and movable fence portions


22


and


24


, respectively, extending in a mutually aligned lateral direction, and with the movable fence portion


24


being laterally spaced away from the fixed fence portion


22


. Such lateral spacing or gap between the fixed and movable fence portions


22


and


24


, respectively, provides clearance for the saw blade to perform a cutting operation completely through the workpiece


11


, regardless of the mode or type of cutting operation being performed. As is discussed in more detail below, the movable fence portion


24


is laterally movable toward and away from the fixed fence portion


22


in order to allow the operator to selectively adjust the clearance gap therebetween and thus accommodate the particular cutting operation being performed.




As is typical in this type of equipment, the compound miter saw


10


depicted in the drawings is capable of a number of different cutting modes or positions. Such positions include those for straightcross-cutting operations, straight miter-cutting operations, bevel cutting operations, and various combinations of bevel cutting and miter cutting, commonly called compound cutting operations, with the adjustable fence assembly


20


being adjustable to provide the minimum required clearance gap between the fixed and movable fence portions


22


and


24


, respectively, in any of these cutting modes.




These various cutting operations or working modes, or combinations thereof, are accomplished by way of a compound pivot mechanism


34


, including a pivot arm assembly


21


, which is pivotally interconnected with the rotatable table assembly


13


. The pivot arm assembly


21


includes a pivot mechanism


23


providing for pivotal movement of the saw blade


14


into and out of engagement with the workpiece


11


, and a pivot mechanism


25


providing for pivotal movement of the saw blade


14


among a number of square or bevel cutting configurations. Lateral swinging movement is accomplished by way of the above-mentioned table assembly


13


, which is disposed for rotation relative to the base assembly


12


, thus accommodating movement among the various cutting configurations.




The pivot arm assembly


21


includes a bifurcated lower and rearward end configuration, with this portion of the pivot arm assembly


21


being split to form a pair of pivot legs


29


and


31


with a space therebetween for receiving a dust duct


33


therebetween. The dust duct


33


has a longitudinal centerline


33


′, and further has a preferably rectangular-shaped dust-receiving opening


35


at its forward end, a transitional intermediate portion


37


, and a preferably circular outlet opening


39


, to which any of a number of suitable dust-conveying fittings


47


, or other accessories, can be attached.




As is shown in the end elevation view of

FIG. 4

, as well as schematically, or diagrammatically, represented in

FIGS. 5 through 7

, the dust duct


33


pivotally moves with the pivot arm assembly


21


and/or the rotatable table assembly


13


, and thus with the saw blade


14


, into and out of engagement with the workpiece


11


(or even a workpiece


11




a


of different size or shape) in any of the square cross-cutting, bevel-cutting, miter-cutting, or compound miter-cutting operations of which the compound miter saw


10


is capable. However, because the dust duct


33


is fixedly interconnected with the pivot arm assembly


21


, its position and orientation relative to the saw blade


14


remains constant during any of these operational modes or configurations, thus contributing greatly to the consistency and effectiveness of the dust collection system in the compound miter saw


10


, or in other devices having movable work-performing tools.




Preferably, as shown in

FIGS. 4 and 5

, the constant position and orientation of the dust duct


33


is such that the dust-receiving opening


35


is aligned substantially along a line


43


between the dust-receiving opening


35


and the periphery of the saw blade


14


, with the line


43


extending along a tangent to the rotation of the saw blade


14


at a location thereon at which the saw blade


14


engages the workpiece


11


(or


11




a


). In most, if not all, applications of the present invention, the effectiveness of the dust collection system is maximized when the compound miter saw


10


(or other work-performing device) is configured such that the line


43


is along a tangent to the rotation of the saw blade


14


(or other cutting tool) at a location


45


at which the saw blade


14


(or other cutting tool) exits the workpiece, with such tangent extending to the center of the dust-receiving opening


35


, and with such orientation remaining constant regardless of the position of the movable saw blade


14


(or other cutting tool).




By way of such an arrangement, the dust duct


33


(and the dust-receiving opening


35


) can be much smaller than would otherwise be required of a stationary dust collection duct in order to accommodate the wide variance of positions and movement of the saw blade


14


(or other cutting tool) in a device such as the compound miter saw


10


. In addition, in a vacuum-powered dust extraction application (such as that discussed below in connection with

FIG. 8

, for example), the dust-conveying kinetic energy provided by such a system can be better concentrated in the area to which dust or chips are propelled by the blade or cutting tool. Still further contributing to the effectiveness of the dust collection system of the present invention is the fact that the position and orientation of the dust duct


33


, and thus the dust-receiving opening


35


, remains constant relative to the saw blade


14


regardless of the movement or adjusted position of either of the blade guard


16


or the fence assembly


20


. Thus the present invention provides a distinct performance advantage over dust collection ducts or openings attached to, or incorporated into, either of these components.





FIGS. 6 and 7

schematically or diagrammatically illustrate a significant feature of the present invention wherein the orientation of the dust receiving opening


35


of the dust duct


33


remains constant relative to the saw blade


14


, regardless of the operational configuration in which the compound miter saw


10


is used. In

FIG. 6

, a miter-cutting operation is diagrammatically illustrated, with exemplary miter-cutting positions of the blade


14


, the dust duct


33


, and the dust-receiving opening


35


being shown in phantom lines and indicated by reference numerals


14




a


,


33




a


, and


35




a


, respectively.

FIG. 7

similarly diagrammatically illustrates exemplary bevel-cutting positions of these components in phantom lines and being indicated by reference numerals


14




b


,


33




b


, and


35




b


, respectively. One skilled in the art will readily appreciate that an exemplary compound cutting operation would involve a combination of these two configurations, as well as readily recognizing that the orientation of the dust-receiving opening


35


and the dust duct


33


remains constant relative to the saw


14


in any of these configurations, and in both a raised, at-rest position and a work-engaging position (as shown with reference to FIGS.


1


and


4


). Furthermore, as is shown in

FIGS. 1 through 4

, for example, the dust duct


33


is separate and independent from the blade guard


16


and is therefore not affected by guard movement or adjustment.




In

FIG. 8

, the dust duct


33


is shown with its outlet opening


39


optionally connected, by way of a flexible hose or conduit


51


, to an accessory dust collection receptacle assembly


53


. The assembly


53


preferably includes a removable collection vessel or bin


57


with a conventional centrifugal separator


59


emptying into the bin


57


. As a further option, the assembly


53


can include a powered vacuum-producing fan or blower device


61


, shown schematically in

FIG. 8

in phantom lines. With such an optional arrangement, either with or without powered vacuum dust-conveying capabilities, the dust extracted and conveyed away from the saw


10


can be contained and collected for convenient disposal. In lieu of the arrangement shown in

FIG. 8

, however, a conventional dust collection bag accessory


63


can also optionally be provided, as shown schematically in

FIG. 4

, where greater portability is desired.





FIGS. 9 and 10

illustrate an exemplary, generally “funnel-shaped”, configuration for the dust duct


33


, with a preferred generally rectangular cross-section for the dust-receiving opening


35


, and with the transitional intermediate portion


37


converging to a preferred circular outlet opening


39


. As shown in

FIGS. 4 and 5

, for example, an accessory dust deflector or diverter


47


can be advantageously added to the outlet


39


, especially when no accessory collector is used. Such a shape or configuration has been found to be highly effective in dust collection or extraction in experimental prototype versions of the compound miter saw


10


. One skilled in the art will readily recognize, however, that variations or modifications on this configuration, including the adding of accessories as discussed above, may be desirable or required in other types of work-performing devices or applications.




Accordingly, the exemplary compound miter saw


10


constructed in accordance with the principles of the present invention, includes a dust collection system that provides for enhanced dust extraction and diversion away from the operator when performing any of the widely divergent cutting operations, in any of the various operational configurations, of which the compound miter saw


10


is capable. Furthermore, it provides such increased effectiveness regardless of the size or shape of the workpiece (within the saw's design parameters) and regardless of the movement or position of the guard or fence. All of such features greatly contribute to the well-being and comfort of the operator, as well as the cleanliness of the work area.




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 may be made therein without departing from the spirit and scope of the invention as defined in the following claims.



Claims
  • 1. A compound miter saw comprising:a base; a table rotatably disposed on said base, said table having a table plane and an axis of rotation substantially perpendicular to the table plane; a first fence mounted on said base and having a first highest point from the table plane; a second fence mounted on said base and having a second highest point from the table plane, the first and second fences defining a fence plane and being mounted such that the fence plane is a fixed non-adjustable distance from the axis of rotation of the table; a first pivot mechanism rotatably connected to the table for rotation about a bevel axis, the first pivot mechanism defining a bevel plane, the bevel plane being substantially parallel to and at a fixed non-adjustable distance from the axis of rotation of the table; a pivot arm pivotally connected to a second pivot mechanism, the pivot arm comprising a pair of spaced-apart leg portions and a web connected to the leg portions; said second pivot mechanism connected to the first pivot mechanism, a part of each leg portion being pivotally attached to the second pivot mechanism, the second pivot mechanism mounting the pivot arm for movement about a chopping axis, the chopping axis being lower than at least one of the first and second highest points; a rotatable cutting tool mounted on the pivot arm for cutting a workpiece, the cutting tool and pivot arm being pivotable about the chopping axis for selective chopping movement where the cutting tool moves towards the table in order to cut the workpiece; and a generally linear dust-receiving duct having a longitudinal centerline, an inlet for receiving dust during performance of a workpiece cutting operation, and an outlet for exhausting dust during the performance of the cutting operation, wherein the dust-receiving duct is positioned in the space between the leg portions such that the outlet is located at one side of the web, rearward from the inlet located at an opposite side of the web; the dust-receiving duct is oriented relative to the cutting tool so that a tangent line of the cutting tool extends into the inlet, the tangent line originating at about a point of intersection between a locus of points formed by the rotation of the periphery of the cutting tool and a portion of the fence plane contained between the first highest point, the second highest point and the table plane, the tangent line and the longitudinal centerline of the dust-receiving duct being generally coplanar defining a duct plane that is generally perpendicular to said chopping axis; and the orientation of the dust-receiving duct remains substantially constant relative to the cutting tool during the cutting operation.
  • 2. The saw of claim 1, wherein the dust-receiving duct is fixedly interconnected to the pivot arm.
  • 3. A compound miter saw comprising:a base; a table defining a table plane, pivotally mounted to the base for movement about a miter axis perpendicular to the table plane for locating the table at a plurality of miter angle settings; a first fence mounted on one side of the base; a second fence mounted on the other side of the base, the first and second fences having coplanar surfaces defining a fence plane, the first and second fences being mounted such that the fence plane is a fixed non-adjustable distance from the miter axis; a rotatable cutting tool; a motor connected to and driving the cutting tool; a pivot arm comprising a pair of legs and a web connected between the legs, each leg pivotally mounted to the table and supporting the cutting tool (1) for pivotal movement about a chopping axis to enable the cutting tool to move toward and away from the table for cutting a workpiece and (2) for movement about a bevel axis, and said chopping axis being pivotable about said bevel axis to define a bevel plane, said bevel plane being substantially parallel to and at a fixed non-adjustable distance from the miter axis of the table; and a generally linear dust-receiving duct having a longitudinal centerline and being located between the legs, the duct extending through the web and having an inlet on a front side of the web for receiving dust when cutting the workpiece and an outlet on a rear side of the web for exhausting the dust; the duct oriented relative to the cutting tool such that during rotation of the cutting tool, a line tangent to the periphery of the cutting tool extends into the inlet of the duct, the tangent line originating at about a point formed by the intersection of the periphery of the cutting tool and a region of the fence plane lying between the first and second fence surfaces, the tangent line and the longitudinal centerline of the dust-receiving duct being generally coplanar defining a duct plane that is generally perpendicular to said chopping axis; and the orientation of the duct remaining substantially constant relative to the cutting tool when the cutting tool is pivoted about the chopping axis for cutting the workpiece.
  • 4. The saw of claim 3, wherein the dust-receiving duct is fixedly interconnected to the pivot arm.
Parent Case Info

This is a continuation of U.S. patent application Ser. No. 09/163,896 filed Oct. 1, 1998 (pending), which is a continuation of application Ser. No. 08/600,907 filed Feb. 13, 1996, now U.S. Pat. No. 5,819,619, which is a continuation of application Ser. No. 08/329,766 filed Oct. 27, 1994 (now abandoned), which is a continuation of application Ser. No. 08/088,266 filed Jul. 7, 1993 (now abandoned), which is a continuation of application Ser. No. 07/774,767 filed Oct. 9, 1991 (now abandoned).

US Referenced Citations (40)
Number Name Date Kind
922843 Bemiller May 1909 A
1476196 Dobyne Dec 1923 A
1552553 Georgia Sep 1925 A
1830151 Wilderson Nov 1931 A
1888679 Knapp Nov 1932 A
3322169 Hilliard May 1967 A
3339597 Kohler Sep 1967 A
3401724 Kreitz Sep 1968 A
3585980 Mellor Jun 1971 A
3998121 Bennett Dec 1976 A
4028975 Bennett Jun 1977 A
4063478 Stuy Dec 1977 A
4144781 Kreitz Mar 1979 A
4150598 Berends et al. Apr 1979 A
4201256 Truham May 1980 A
4241505 Bodycomb, Jr. et al. Dec 1980 A
4253362 Olson Mar 1981 A
4255995 Connor Mar 1981 A
4300426 Weaver Nov 1981 A
4367665 Terpstra et al. Jan 1983 A
4517869 Kuhlmann et al. May 1985 A
D282346 Pioch Jan 1986 S
4576072 Terpstra et al. Mar 1986 A
4694720 Brickner, Jr. et al. Sep 1987 A
4694721 Brickner, Jr, Sep 1987 A
4721023 Bartlett et al. Jan 1988 A
D295823 Brickner, Jr. et al. May 1988 S
4794740 Keith et al. Jan 1989 A
4799416 Kumasaka et al. Jan 1989 A
4869142 Sato et al. Sep 1989 A
D305542 Miyamoto et al. Jan 1990 S
D306031 Ushiwata et al. Feb 1990 S
4934233 Brundage et al. Jun 1990 A
5038650 Hodge Aug 1991 A
5084972 Waugh Feb 1992 A
D331416 Fushiya et al. Dec 1992 S
D336652 Arehart Jun 1993 S
5297463 O'Banion et al. Mar 1994 A
5421228 Fukinuki Jun 1995 A
5819619 Miller et al. Oct 1998 A
Foreign Referenced Citations (10)
Number Date Country
2350245 Apr 1975 DE
2459440 Aug 1976 DE
3136590 Mar 1983 DE
8815327 May 1989 DE
0048331 Aug 1981 EP
0055896 Nov 1981 EP
1315720 May 1973 GB
1468096 Mar 1977 GB
1499692 Feb 1978 GB
1133993 Oct 1979 IT
Non-Patent Literature Citations (11)
Entry
Exhibit A, showing a copy of two photographs of Mikita Model LS 1011 compound saw, date unknown.*
Exhibit B, instruction manual for the Mikita LS 1011, date unknown.*
Exhibit C, showing a copy of seven photographs of the Delta Model 34-080 saw, date unknown.*
Exhibit D, showing four pages of photographs of an Elu TGS 71 miter saw, date unknown.*
Video tape prepared by Makita USA showing operation of the Elu TGS miter saw.
Two photographs of Makita Model LS 1011 compound saw (previously submitted to U.S. Patent Office and identified as Exhibit A in Information Disclosure Statement dated Jan. 11, 2000).
Instruction manual for the Makita LS 1011 (previously submitted to U.S. Patent Office and identified as Exhibit B in Information Disclosure Statement dated Jan. 11, 2000).
Seven photographs of the Delta Model 34-080 saw (previously submitted to U.S. Patent Office and identified as Exhibit C in Information Disclosure Statement dated Jan. 11, 2000).
Color photographs of an Elu TGS 71 miter saw (previously submitted to U.S. Patent Offce and identified as Exhibit D in Information Disclosure Statement dated Jan. 11, 2000).
Intercompany invoice of Makita USA showing the transfer of the TGS71 miter saw (previosuly submitted to U.S. Patent Office and identified as Exhibit A in Information Disclosure Statement dated Mar. 13, 2000).
Catalog showing the TGS71 miter saw (previously submitted to U.S. Patent Office and identified as Exhibit B in Information Disclosure Statement dated Mar. 13, 2000).
Continuations (5)
Number Date Country
Parent 09/163896 Oct 1998 US
Child 09/524378 US
Parent 08/600907 Feb 1996 US
Child 09/163896 US
Parent 08/329766 Oct 1994 US
Child 08/600907 US
Parent 08/088266 Jul 1993 US
Child 08/329766 US
Parent 07/774767 Oct 1991 US
Child 08/088266 US