US20100269353A1 - Portable cutting device with on-board debris collection - Google Patents

Abstract

A portable cutting device having a cutting tool for cutting a material. The cutting device includes a motor driving the cutting tool and a shroud at least partially enclosing the cutting tool. The shroud defines a debris accumulation chamber for gathering debris created by the cutting tool cutting the material. An impeller is operatively coupled to the motor and driven by the motor to create suction pressure to draw the debris out of the debris accumulation chamber and into a collection bag.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority to and all benefits of U.S. Provisional Application No. 61/172,607, filed Apr. 24, 2009, entitled “PORTABLE CUTTING DEVICE WITH ON-BOARD DEBRIS COLLECTION,” the complete disclosure of which is hereby incorporated by reference. The complete disclosure of U.S. application Ser. No. 10/939,440, filed Sep. 14, 2004, entitled “SELF-CONTAINED VACUUM SAW,” now U.S. Pat. No. 7,328,512, is also hereby incorporated by reference.
FIELD OF THE INVENTION
• The present invention relates to a portable cutting device for cutting a material such as wood, drywall, concrete, roof tiles, slate, etc, which creates debris. More specifically the present invention relates to the portable cutting device having an on-board debris collection system.
BACKGROUND OF THE INVENTION
• Portable cutting devices are well known in the art of carpentry and construction. Such devices include portable circular saws, concrete saws, routers, and the like. When using these devices to cut through materials such as wood, drywall, concrete, roof tiles, slate, etc., cutting debris is created, e.g., saw dust, concrete dust and larger particles. In most cases, protective gear is needed to avoid health hazards associated with this debris. Additionally, the debris accumulates in the area in which the cutting device is being used making clean-up time consuming and difficult. Accordingly, there is a need for portable cutting devices with debris collection systems to collect the dust and larger particles.
• Prior art portable cutting devices have been developed to include debris collection systems. These systems typically include a housing defining a debris accumulation chamber and a collection port on the housing for connecting to a vacuum source. The vacuum source draws the debris through the collection port into a collection area. The vacuum source is off-board, meaning that the vacuum source is separate from the cutting device. As a result, when transporting the cutting device between work sites, a vacuum source must be made available at each of the work sites.
SUMMARY OF THE INVENTION AND ADVANTAGES
• A portable cutting device having a cutting tool for cutting a material is provided. The cutting device includes a motor driving the cutting tool and a protective housing at least partially enclosing the cutting tool. The protective housing defines a debris accumulation chamber for gathering debris created by the cutting tool. An impeller is operatively coupled to the motor and driven by the motor to create suction pressure to draw the debris out of the debris accumulation chamber and into a collection bag. A vacuum housing protects the impeller and the collection bag is coupled to the vacuum housing. The impeller and collection bag form part of an on-board debris collection system thereby eliminating the need for a separate off-board vacuum source and debris collection area.
• The present invention provides a cutting device that includes a material cutting blade, a shroud which at least partially encloses the blade and relative to which the blade is supported for relative movement, a debris accumulation chamber within the shroud in fluid communication with the blade and into which material debris generated by the blade during cutting is received, a source of vacuum in fluid communication with the debris accumulation chamber, a pressure equalization chamber in fluid communication with the source of vacuum, and a plurality of vacuum conduits extending between the debris accumulation chamber and the pressure equalizing chamber, each conduit having an inlet and an outlet, the debris accumulation chamber having an opening into a conduit inlet, the pressure equalization chamber having an opening into a conduit outlet. Airflow induced by the source of vacuum is drawn from the conduit inlets to the conduit outlets, material debris received in the debris accumulation chamber carried by the induced airflow toward the vacuum source and the pressure equalization chamber.
• Certain embodiments of the cutting device include a vacuum housing having an exhaust port from which the induced airflow and material debris carried thereby exits the vacuum housing.
• In certain embodiments of the cutting device, the source of vacuum is contained in the vacuum housing, and the induced airflow and material debris carried thereby may be expelled from the exhaust port under a pressure greater than the pressure in the pressure equalization chamber.
• Certain embodiments of the cutting device include a collection container attached to the exhaust port and into which the induced airflow and material debris carried thereby is received, material debris received in the collection container retained therein.
• In certain embodiments of the cutting device, the collection container may have a wall through which the induced airflow received thereby passes. The collection container may include a porous inner container disposed within a porous outer container, the porosity of the inner container being less than the porosity of the outer container.
• In certain embodiments of the cutting device, each outlet of the plurality of vacuum conduits opens individually into the pressure equalization chamber.
• In certain embodiments of the cutting device, the inlets of the plurality of vacuum conduits are sequentially positioned along the path of blade travel within the shroud.
• In certain embodiments of the cutting device, the blade is a circular saw blade rotatably supported within the shroud, the perimeter of the saw blade having a circumferentially distributed plurality of teeth, with the inlets of the vacuum conduits positioned at locations on the shroud that are sequentially passed by each saw blade tooth.
• In certain embodiments of the cutting device, the shroud substantially surrounds an upper portion of the circular saw blade and the cutting device may include a lower blade guard connected to the shroud, the lower blade guard having movement relative to the shroud between an extended position in which it substantially surrounds the perimeter of the lower portion of the saw blade, and at least one retracted position into which it is received in the debris accumulation chamber and at least partially exposes the perimeter of the lower portion of the saw blade. The lower blade guard has a surface in which is provided at least one aperture that is moved substantially into alignment with a vacuum conduit inlet in a retracted position. In such an embodiment, material debris generated by the blade during cutting may be carried with the induced airflow into the conduit inlet from a location between the saw blade perimeter and the blade guard through the aperture substantially aligned with the conduit inlet.
• Certain embodiments of the cutting device include a deck plate through which the blade extends and to which the shroud is connected, a base plate attached to the deck plate and through which the blade extends, the base plate being positioned between the deck plate and a material-engaging portion of cutting blade. The shroud and the base plate have selective cut depth and positions in which the distances from the base plate to which the material-engaging portion of cutting blade extends and the relative angle between the base plate and the material-engaging portion of cutting blade are respectively varied. In such an embodiment, the blade may be disposed in a space defined by a surrounding wall extending between the base plate and the shroud that is substantially sealed against air leakage through the wall, throughout the operating ranges of cut depth and cut angle positions.
• In certain embodiments of the cutting device, substantially all of the air drawn by the vacuum source into the debris accumulation chamber is solely through an opening in the base plate through which the blade extends.
• The surrounding wall of certain such embodiments includes an expandable first bellows located between the deck plate and the shroud, the first bellows being correspondingly expanded and compressed between different cut depth positions with corresponding relative movement between the deck plate and the shroud.
• In certain such embodiments of the cutting device, the base plate and the deck plate are pivotably attached to each other, and the surrounding wall includes a expandable second bellows located between the deck plate and the base plate, the second bellows being correspondingly expanded and compressed between different cut angle positions with corresponding relative movement between the deck plate and the base plate.
• In certain embodiments of the cutting device, the surrounding wall includes a transparent window located between the deck plate and the shroud, the cutting blade and material being cut visible to an operator through the window during cutting operations.
BRIEF DESCRIPTION OF THE DRAWINGS
• Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
• FIG. 1 is a right-side, front perspective view of a portable cutting device;
• FIG. 2 is a right-side front perspective view of the portable cutting device in an angled state;
• FIG. 3 is a left-side front perspective view of the portable cutting device in an angled state;
• FIGS. 4A and 4B right-side front perspective exploded views of the portable cutting device;
• FIG. 5 is a front view of drive train components and blade of the portable cutting device;
• FIG. 6 is a left-side rear perspective view of the motor casing of the portable cutting device;
• FIG. 7 is a right-side front perspective view of the motor casing of the portable cutting device;
• FIG. 8 is a left-side front perspective view of the left-hand handle half;
• FIG. 9 is a right-side front perspective view of the right-hand handle half;
• FIG. 10 is a partial right-side front perspective exploded view of vacuum housing-related components of the portable cutting device;
• FIG. 11 is a left-side rear perspective exploded view of the vacuum housing of the portable cutting device;
• FIG. 12 is a right-side front perspective view of the vacuum housing of the portable cutting device;
• FIG. 13 is a right-side front perspective view of the impeller and its drive shaft;
• FIG. 14 is a right-side front perspective view of the upper blade enclosure;
• FIG. 15 is a fragmented sectional view of the upper blade enclosure and the retracted lower blade guard, and the saw blade;
• FIG. 16 is a partially sectioned, front view of the drive train components and vacuum conduits of the portable cutting device;
• FIG. 17A is a right-side front perspective exploded view of the lower blade guard and its bearing;
• FIG. 17B is a left-side view of the lower blade guard and its bearing;
• FIG. 18 is a right-side front perspective view of the transparent side window of the portable cutting device;
• FIG. 19 is a right-side front perspective view of the main bellows;
• FIG. 20 is a right-side front perspective view of the transparent blade window;
• FIG. 21 is right-side front perspective view of the rear bellows;
• FIG. 22 right-side front perspective view of the lower bellows;
• FIGS. 23A and 23B are fragmented front views of the portable cutting device in a zero angled state, at comparatively greater and lesser blade depth positions, respectively;
• FIGS. 24A and 24B are fragmented front views of the portable cutting device in a 45-degree angled state, at comparatively greater and lesser blade depth positions, respectively;
• FIG. 25 is an enlarged, fragmentary front view of the portable cutting device in a 45-degree angled state; and
• FIG. 26 is a fragmented front view similar to that ofFIG. 24B, but with a portion of the base plate removed to reveal the lower bellows.
• It is to be noted that the Figures are not necessarily drawn to scale. In particular, the scale of some of the elements of the Figures may be exaggerated to emphasize characteristics of the elements. It is also noted that the Figures are not necessarily drawn to the same scale. Elements shown in more than one Figure that may be similarly configured have been indicated using the same reference numerals.
• While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and may herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
• Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a portable cutting device for cutting a material M such as wood, drywall, concrete, roof tiles, slate, etc., is generally shown at30. The cuttingdevice30 is defined as being portable because of the ability to easily move thecutting device30 between work sites. The cuttingdevice30 preferably weighs less than 50 lbs, more preferably less than 35 lbs, and most preferably less than 20 lbs. The cuttingdevice30 is also preferably handheld, such that it can be maneuvered, lifted etc. with a single hand.
• Referring toFIGS. 1 and 2, the cuttingdevice30 includessaw casing31 in which is disposed amotor32 which drives acutting tool34. Themotor32 is preferably electrically powered and energized by a 110-volt outlet through a conventional electrical cord C, but themotor32 could also be battery operated. Themotor32 has amain drive shaft36 and thecutting tool34 is operatively coupled to themain drive shaft36 to rotate upon operation of themotor32.
• The cuttingtool34 shown is acircular saw blade34 that rotates counterclockwise, in the direction ofarrow24, to cut up through the material M. The sawblade34 could be configured for cutting through wood, metal, concrete, roof tiles, slate, and the like. Thesaw blade34, which is of a common type known to those of ordinary skill in the art, is generally circular and defines a central aperture for engaging arotational saw shaft116, as best shown inFIGS. 2 and 20.
• Referring toFIGS. 2 and 20, themain drive shaft36 drives thesaw shaft116 through a transmission33. The transmission33 includes afirst gear320 fixed to themain drive shaft36 and asecond gear322 fixed to thesaw shaft116. Thegears320,322 are preferably configured to step down rotational speed of thesaw shaft116 compared to themain drive shaft36. The transmission33 is disposed in transmission casing35 (described further below) that covers, secures, and protects itsgears320,322, with a sealed bearing disposed intransmission casing35 to support thesaw shaft116. Themotor casing38 andtransmission casing35 together form a drivetrain housing.
• Agear plate51 defines part of thetransmission casing35 and includes a fixedcollar206 that covers and supports the sealedbearing204, through which extends sawshaft116 supported thereby. Thegear plate51 includes a base53 on which outerfixed collar206 is disposed and from whichcollar206 extends laterally outwardly.Saw blade34 is clamped between anadjacent flange55 and a bolt ornut37 that engages threads formed in or on the end of thesaw shaft116 in the well-known manner, thereby rotatably fixing thesaw blade34 to thesaw shaft116.
• Referring toFIGS. 2-4, themotor32 includes amotor casing38 that encloses and supports the motor components, e.g., brushes32a,stator32b, androtor32c. Themotor casing38 defines amotor cavity39 for receiving thestator32bandrotor32cand a pair ofcavities41 for receiving thebrushes32a. Themotor components32a,32b,32care secured in themotor cavities39,41 using methods well known to those skilled in the art, such as by fasteners, clips, snap-fits, interference-fits, and the like. Themotor casing38 is preferably formed of metal and includes avent40 for exhausting heat generated by themotor32. In other embodiments, themotor casing38 could be formed of a rigid plastic material suitable for supporting themotor32.
• Referring toFIGS. 2-6, ahandle42 is fixed to themotor casing38. A user grasps and holds thehandle42 to manipulate, maneuver and operate thecutting device30 during use. Atrigger44 energizes themotor32 using conventional methods. Thehandle42 supports thetrigger44 for actuation by the user. As shown inFIGS. 5 and 6, thehandle42 is preferably formed in twomating halves42a/42bthat are locked together (via adhesive, mating studs/bores, and/or the like). Thehandle42 defines arear cable port48 for receiving the cord C.
• Themotor casing38 defines a cylindrical outer surface50 (seeFIG. 3). Thehandle42 defines a cylindricalinner surface52 that surrounds and engagesmotor casing surface50. A suitable adhesive could be used to secure thehandle42 to themotor casing38. Mid-bodymotor casing enclosure46 is disposed onmotor casing38 adjacent to left-hand handle part42b, and forms part ofsaw casing31. Mid-bodymotor casing enclosure46 has innercylindrical surface47 that surrounds and engagesmotor casing surface50. A suitable adhesive could be used to secureenclosure46 to themotor casing38.
• Referring back toFIGS. 1 and 2, alower platform assembly54 is coupled to themotor casing38. Thelower platform assembly54 comprises an upper plate ordeck plate56, and a lower plate orbase plate58, which are pivotally coupled together through pivoting or hingedjoints60. Theupper plate56 defines a generallyrectangular blade opening62 for receiving a lower portion of thesaw blade34. Thelower plate58 similarly includes a generallyrectangular blade opening64 for receiving the lower portion of thesaw blade34. Thelower plate58 is adapted to contact and slide along the material M being cut by thesaw blade34.
• Adepth adjustment block66 is fixed to theupper plate56. Thedepth adjustment block66 defines anelongated slot68 for receiving anadjustment screw70 therethrough. A corresponding depth adjustment bracket72 (FIG. 4B) is fixed to handle42. Thedepth adjustment bracket72 defines a threadedbore74 for threadably receiving theadjustment screw70. Theadjustment screw70 has a graspable head orpommel69 and a threaded shaft wherein the threaded shaft fits through theelongated slot68 and threads into the threaded bore74. When tightened, thegraspable head69 frictionally engages an outer surface of thedepth adjustment block66 to hold thedepth adjustment block66 in one of a plurality of adjustable positions by frictionally securing thedepth adjustment block66 between thedepth adjustment bracket72 and thegraspable head69. As a result, thelower platform assembly54 can be adjusted for depth relative to themotor casing38 via theadjustment screw70.
• Referring toFIGS. 1,2, and7, a firstangle adjustment block71 is fixed to theupper plate56 and a secondangle adjustment block73 is fixed to thelower plate58. The firstangle adjustment block71 defines abore76 for receiving anangle adjustment screw78. Theangle adjustment screw78 has a threaded shaft and agraspable head81 configured to form a lever. Awing nut80 threadably engages the threaded shaft of theangle adjustment screw78 on a rear surface of the firstangle adjustment block71.Wing nut80 may be welded or permanently fixed to the firstangle adjustment block71. Alternatively, bore76 may be threaded to engage the threads ofscrew78, withwing nut80 omitted altogether. The secondangle adjustment block73 defines a second elongated,arcuate slot88, preferably semicircular in shape and centered about the axis of pivot joint60, in which is received the threaded shaft of theangle adjustment screw78. When tightened, thegraspable head81 frictionally engages a front surface of the secondangle adjustment block73 to hold thelower plate58 in one of a plurality of angular positions by frictionally securing the secondangle adjustment block73 between the firstangle adjustment block71 and thegraspable head81.
• The secondangle adjustment block73 is preferably graduated withangular markings79 such that thelower plate58 can be pivotally adjusted relative to theupper plate56 at a known angle therebetween. The angular markings preferably include graduations of 1 degree spanning from zero to 45 degrees. This allows the user to cut the material at a known angle. For instance, the user can cut through wood trim pieces at a 45-degree cut angle.
• Referring to FIGS.2 and8-10, avacuum housing90 is coupled to themotor casing38 and a blade shroud orupper blade enclosure110, with bolts. Thevacuum housing90 forms part ofsaw casing31 and includes amain housing portion92, animpeller housing portion94, and aimpeller cover97. Themain housing portion92 defines a pressure-equalizing chamber96 (or pressure chamber96) and theimpeller housing portion94 and impeller cover97 together define an impeller chamber98 (seeFIG. 10). The generally cylindricalimpeller housing portion94 forms a substantially tangentially extendingexhaust port95. Theimpeller cover97 is mounted to theimpeller housing portion94 using fasteners F disposed in through bores T defined in theimpeller cover97 and threaded into bores B in theimpeller housing portion94.Cover97 hasgear housing136 formed on its exterior planar surface.Housing136 may, in some embodiments, have a separately attached outerplanar cap138 to facilitatecover97 being molded with the side walls ofhousing136.
• A plurality of throughbores101 are also defined through themain housing portion92 are mated toholes105 inimpeller housing portion94, which receive fasteners (not shown) to mount themain housing portion92 to themotor casing38 at a first end of themotor casing38.
• Animpeller100 is rotatably supported in theimpeller chamber98 on astub shaft135, which extends throughaperture106 ofcover97 and intogear housing136, wherein it is rotatably supported and axially fixed relative tocentral hub103 ofcover97, by a sealedbearing104 mounted on the outward side ofhub103, withingear housing136. The axially outward end ofstub shaft135 disposed ingear housing136 hasworm gear336 formed thereon, which is enmeshed withworm338 provided on theend segment129 offlexible shaft128, which is attached to gearhousing136. Themotor32 rotatably drives theimpeller100 throughflexible shaft128 in the direction indicated byarrow26 to create airflow and corresponding vacuum pressure in the pressure-equalizingchamber96. Theimpeller100 can be formed of metal or plastic materials such as Lexan®, nylon, or other relatively rigid plastic materials.
• Referring specifically toFIG. 8A, abore99 is defined throughend cap118 ofsaw casing31, which is fixed tomotor casing38. Attached to endcap118 isend segment102 of flexible drive shaft128 (seeFIG. 2). Driveshaft end segment102 is adapted for receipt intobore99 and rotatably fixed tomotor drive shaft36.Flexible drive shaft128, which includes rotating, torque-carrying flexible cable disposed within a flexible surrounding, nonrotating casing or sheath, is of a type well-known in the power transmission art that is available from a number of sources such as, for example, S.S. White Technologies, Inc. of Piscataway, N.J., or Suhner Manufacturing, Inc. of Rome, Ga.
• Referring toFIGS. 10-12, theimpeller100 hascircular plate122 that superposes the inside planar surface ofcover97, and to which a plurality ofblades124 or fins are interconnected.Circular plate122 has acentral hub130 extending normally therefrom which defines acentral hub130 to whichblades124 are also interconnected, and from which they extend radially outwardly.Hub130 defines a central bore into whichstub shaft135 is inserted, withimpeller100 andstub shaft135 rotatably and axially fixed together.Impeller100 andshaft135 may be interfixed through an interference fit, clamped engagement, or through fasteners, for example.
• Planar wall120 ofhousing portion94 defines anaperture126 that approximates a size of the pressure-equalizingchamber96 such that the pressure-equalizingchamber96 opens directly into the plurality ofblades124. The pressure-equalizingchamber96 opens into theimpeller chamber98 in a direction generally transverse to, and preferably perpendicular to,plate122 ofimpeller100.
• Referring specifically toFIGS. 2,8A,8B, a plurality ofvacuum conduits406 are disposed about thesaw casing31 and extend laterally therealong, between saw blade shroud orupper enclosure110 andmain housing portion92 ofvacuum housing90. In the depicted embodiment, threevacuum conduits406 are utilized. Thevacuum conduits406 communicate with the pressure-equalizingchamber96 throughopenings109 in the main housing portion92 (seeFIG. 10). It should be appreciated that more orfewer vacuum conduits406 could be employed. Thevacuum conduits406 extend between upstream ends located atenclosure110, and downstream ends located atmain housing portion92. The pressure-equalizingchamber96 assists in equalizing the vacuum or suction pressure drawn in each of thevacuum conduits406 by providing a volume of space, upstream of theimpeller100 and downstream of thevacuum conduits406, in which a suction pressure can be established.
• In the depicted embodiment, thevacuum conduits406 are formed in multiple segments defined by casing components or other components that define the conduits. These components may be connected together by being sealably interfitted, or through the use of adhesive and/or couplers, and/or the like. The sequentially encountered sections ofconduits406 along the general direction of airflow are described as duct heads408,tubes410, right-hand handle passages412, left-hand handle passages414,mid-body passages415, andvacuum housing passages422.Mid-body passages415 are defined by the cooperating semi-cylindrical surfaces416 formed on mid-bodymotor casing enclosure46 and semi-cylindrical surfaces418 formed defined bymid-body window420 attached toenclosure46.Passages422 inmain housing portion92 ofvacuum housing90 define individual outlets ofvacuum conduits406 that each open intopressure equalization chamber96.
• Thevacuum conduits406 preferably have a generally circular cross-section, but their cross-sections may instead be generally rectangular in shape or other shapes, and can vary in cross-sectional shape over their lengths. Each of thevacuum conduits406 preferably has a cross-sectional area at the blade shroud orupper enclosure110 that is larger than the cross-sectional area at themain housing portion92. The cross-sectional area may taper gradually from theupper enclosure110 to themain housing portion92. Threevacuum conduits406 are illustrated and include a first or leading vacuum conduit406a, a second or center vacuum conduit406b, and a third or trailing vacuum conduit406c.
• Referring toFIGS. 2,13 and13A, theupper enclosure110 at least partially encloses an upper portion of thesaw blade34, and defines an upper section of a debris accumulation chamber112 (seeFIG. 22). Theupper enclosure110 has a generally semi-circular shape that approximates the shape of thesaw blade34. Theupper enclosure110 is generally U-shaped in cross-section taken in planes containing the axis of rotation ofsaw shaft116, except at the openings to vacuumconduits406.
• The inlets to the first406aand second406bvacuum conduits are disposed at a front section of theupper enclosure110. The inlet to the third vacuum conduit406cis disposed at a rear section of theupper enclosure110. The front section is defined as the front half of theupper enclosure110, while the rear section is defined as the rear half of theupper enclosure110. The first vacuum conduit406ais preferably located at the frontmost location on the front section to collect debris at the front of thedebris accumulation chamber112. The third vacuum conduit406cis preferably located on the rear section to collect debris at the rear of thedebris accumulation chamber112. Together the vacuum conduits406a,406b,406cdefine separate vacuum paths for the debris.
• A plurality of duct heads408a,408b,408care integrally formed with the upper enclosure110 (or alternatively can be formed separately), and define inlets to their respective conduits406a,406b,406c. The duct heads408a,408b,408ceach have a surrounding collar adapted to receive and sealably engage the respective upstream ends oftubes410a,410b,410c. The upstream ends oftubes410 may form an interference fit with the collars or be adhesively bonded to the collars.
• Referring to back toFIG. 2, aninner side150 of theupper enclosure110 is mounted to thetransmission casing35 to close thedebris accumulation chamber112 on the inside. More specifically,inner side150 is integrally connected to anouter rim145, which surroundsintermeshed gears320,322 of transmission33, andintegral wall146.Gear plate51,outer rim145, andwall146 together definetransmission casing35. In the blade-surrounding portion ofenclosure110, theinner side150 and anouter side152 ofupper enclosure110 are interconnected by integral,semi-circular shoulder155.
• Outer side152 of theupper enclosure110 defines asemicircular opening153 in which is disposed aside window160 that closes theopening153 and the outward side ofdebris accumulation chamber112. Theside window160 includes atransparent section162 formed of transparent plastic and has a semicircularouter periphery164 in which is a circumferential distribution ofholes166. Thetransparent section162 allows the user to view thesaw blade34. Theouter periphery164 interfaces and abuts the inner surface ofouter side152 along the periphery of opening153 that is provided withholes168 that correspondingly align withholes166. Fasteners (not shown) extend through alignedholes166,168 to securewindow160 toenclosure110.Side window160 includesarcuate slot170 centered abut the axis of rotation ofblade34. Theslot170 is adapted to receiveshaft172, the end of which is fixed toouter side205 of manually retractablelower blade guard200. The outward end ofshaft172 is provided withknob174 which may be grasped by the operator to manually moveshaft172 alongslot170 to retractlower blade guard200 intoupper blade enclosure110 to expose the edge ofblade34, which is desirable for making plunge cuts into the surface of material M, rather that from an edge thereof.Lower blade guard200 may be rotatably biased into its extended position in which it shields the edge ofblade34, by atension spring175 operably engaged withenclosure110 andguard200, in a conventional manner well-known in the circular saw art.
• Upper blade enclosure110 definesbottom edge182 andside window160 defines bottom edge176. Bottom edges176 and182 are substantially flush and lie in a plane. Referring toFIGS. 2 and 17, a flexiblemain bellows180 interconnectsbottom edges176,182 along a corresponding upper rim oredge188. The flexible bellows180 is flexible and expandable between compressed and extended states to accommodate differing cutting depths, i.e., when thelower platform assembly54 is raised and lowered relative toblade34 to provide more or less blade cutting depth. Flexiblemain bellows180 has opposite longitudinal ends194,195 that face each other, and slidably engage respectively interfacing, parallelplanar sides196,197 ofblade enclosure110.Bellows180 has lower rim or edge186 that is interconnected with corresponding upper rim or edge190 oftransparent blade window192.Blade window192 has the same general shape asmain bellows180, and may be molded of a suitable transparent, substantially rigid plastic material, to allow the operator to view the cut line.Bosses193 are formed inblade window192 through which fasteners F extend to secureblade window192 todeck plate56.Bottom edge198 ofblade window192 is closely received intoblade opening62, and its outward side has ashoulder199 that abutsdeck plate56 along the outer longitudinal edge ofopening62.Blade window192 has opposite longitudinal ends212,213 that face each other, and abut and seal against respectively interfacing, parallelplanar sides196,197 ofblade enclosure110.
• More particularly,upper rim188 ofmain bellows180 may define a peripheral groove adapted to receive thebottom edges176,182 ofside window160 andupper enclosure110, andlower rim186 ofmain bellows180 may similarly define a peripheral groove adapted to receiveupper edge190 oftransparent blade window192. Thebottom edges176,182 and theupper edge190 may be press-fitted and adhesively sealed in the respective peripheral groove ofbellows180. In one embodiment, theflexible bellows180 has an accordion shape. In other embodiments, theflexible bellows180 is formed of a stretchable plastic material capable of stretching greater than 100% such as polyurethane. The flexible bellows180 is also preferably transparent.
• Additionally, the portion of the upper surface ofdeck plate56 immediately belowtransmission casing35 ofenclosure110 and along the longitudinal inward edge ofblade opening62 is recessed below the adjacent portions of the deck plate upper surface. The recessedportion218 ofdeck plate56 defines aplanar floor220 that is parallel with planarbottom surface222 oftransmission casing35, which extends between itsopposed sides196,197. Extending the entire length of recessedportion218 andsurface222 is rear bellows178.Top surface224 ofrear bellows178 is sealably attached to transmission casingbottom surface222;bottom surface226 ofrear bellows178 is sealably attached tofloor220. Thus, the blade-containing space between blade opening62 indeck plate56 andchamber112 ofupper blade enclosure110, is substantially sealed against air leakage through its enclosing walls.
• Referring back toFIGS. 2 and 7, the inward longitudinal edge ofblade opening64 inbase plate58 is laterally distanced fromblade34 to an extent that it is positioned on the side of recessedportion218 that is opposite theblade34. Extending the length ofblade opening64 is U-shapedlower bellows181, which may be of a material similar tomain bellows180. Thelegs228,229 oflower bellows181 extend substantially perpendicularly from itselongate body230; top andbottom surfaces231,232 oflower bellows181 are respectively sealably attached to the interfacing, superposed surfaces ofdeck plate56 andbase plate58. Aslower platform assembly54 is adjusted about pivotingjoints60, toangle deck plate56 andbase plate58 between zero and 45 degrees, lowerbellows body portion230 is expanded and contracted, while at the terminal ends oflegs228,229 bellows181 remains compressed to a substantially consistent degree regardless of saw blade angle. Thus, bellows181 is arranged to enclose a portion of the space betweenplates56,58 into whichblade opening64 communicates.
• On the outward lateral side ofblade34, elongate, substantiallyplanar slider plate61 extends along the entire length ofblade opening64 inbase plate58. The opposed ends234,235 ofslider plate61 are pivotally attached todeck plate56 near the upperslider plate edge236, which slidably abuts elongate sealingflange240 integrally formed on the deck plate and projecting upwardly and outwardly from its upper planar surface at an angle, away fromblade opening62. The opposed ends234,235 ofslider plate61 are closely fitted between a pair of upstandingplanar sealing flanges242,243 located at opposite longitudinal ends ofblade opening64. The lowerslider plate edge237 is in sliding engagement along its length with the adjacentplanar sealing surface244 ofbase plate58 located between itsupstanding flanges242,243. Asslider plate61 pivots relative todeck plate56, with relative angular movement betweendeck plate56 andbase plate58 about pivot joints60, slider platelower edge237 sealably slides along baseplate sealing surface244, and slider plate ends234,235 sealably slide along the adjacent sealing surface of theirrespective flanges242,243. The opposed ends234,235 ofslider plate61 may be slidably linked, for example, via pin-in-slot joints, withflanges242,243, to ensure sealing engagement between slider platelower edge237 and baseplate sealing surface244. Alternatively,slider plate61 may be pivotably biased relative todeck plate56, for example by a torsion spring (not shown), to ensure sealing engagement between slider platelower edge237 and baseplate sealing surface244. Alternatively,slider plate61 may rely on gravity and/or the air pressure differential between its opposite planar sides during saw operation to ensure sealing engagement between slider platelower edge237 and baseplate sealing surface244. Thus, the blade-containing space between blade opening64 inbase plate58 andchamber112 ofupper blade enclosure110, is also substantially sealed against air leakage at locations belowdeck plate56. The above-described sealing of the blade containing space against the influx of air leakage downstream of (i.e., above)blade opening64 inlower plate58 helps to maintain general sealing of thedebris accumulation chamber112 when thelower plate58 is pivoted for angled cuts. In other words, during saw operation a working vacuum pressure is maintained in thedebris accumulation chamber112 to draw the debris out of thedebris accumulation chamber112 at all cutting angles and depths.
• Referring to FIGS.2 and18-19, alower blade guard200 is pivotally mounted to the fixedcollar206 of thegear plate51. Thelower blade guard200 includes aninner side203 and anouter side205. Thelower blade guard200 includes ahub202 on theinner side203 for supporting a sealedbearing204. The sealedbearing204 is disposed over the fixedcollar206 and is fixed to the fixedcollar206. Thesaw shaft116 rotates within bearing204 of the fixedcollar206. Thus, the fixedcollar206 is fixed from rotation. As a result, thelower blade guard200 pivots about the fixedcollar206 via the sealedbearing204. Thelower blade guard200 at least partially encloses a lower portion of thesaw blade34. Thelower blade guard200 also defines a plurality ofopenings208 in theinner side203 and part of theshoulder210. Whenguard200 is fully retracted, theopenings208, which generally correspond in size and location to the inlets toconduits406 in theupper enclosure110, become aligned with the duct heads408. Abottom shoulder210 spaces theinner side203 from theouter side205.
• Thislower blade guard200 rotates further into theupper enclosure110 as thesaw blade34 cuts through the material M in a conventional manner. Referring toFIG. 18A, when thelower blade guard200 is rotated into theupper enclosure110, theopenings208 assist in providing aligned airflow paths to carry the debris to thevacuum conduits406. This is best illustrated inFIG. 18A. When thelower blade guard200 is rotated into theupper enclosure110, it still surrounds thesaw blade34, just now at an upper portion of thesaw blade34. As a result, there is a need for airflow from thedebris accumulation chamber112 to easily penetrate through the lower blade guard and remain relatively unimpeded as it continues to thevacuum conduits406, andopenings208 assist in this effort.
• Referring back toFIGS. 1 and 2, acollection bag300 is releasably mounted to theexhaust port95 with a clamp orcollet302. In other embodiments, thecollection bag300 can be mounted with a cinching string, elastic band, and the like. Thecollection bag300 is preferably flexible, collapsible, and easily disposable. In other embodiments, thecollection bag300 is washable for coarse work such as cutting materials like wood. The particular type ofcollection bag300 utilized to catch and collect fine debris such as that produced in drywall cutting are in common use in the industry and are well known in the art. Thecollection bag300 is generally porous to allow airflow therethrough, while still trapping debris deposited in thecollection bag300 during operation.
• In one embodiment, shown inFIG. 3, the debris collection assembly includes anouter container301 and aninner container303, both clamped about theexhaust port95 and preferably being bags that are flexible and collapsible. In this embodiment, theinner bag303 may be formed of disposable filter materials such as a Style C Genuine Multi-Filter bag for an Electrolux Tank. Theinner bag303 may be formed with a maximum pore size configured to prevent pass-through of particle diameters of 100 microns or less, more preferably 10 microns or less, most preferably 5 microns or less, and even some embodiments capable of preventing pass through of particles with diameters of 1 microns or less. Theouter bag301 may be fabricated from a synthetic or natural cloth material and be formed with pore sizes configured to prevent pass through of larger material such as wood chips, etc., preferably on the order or 0.5 inches in diameter or less, 0.1 inches in diameter or less, and preferably from about 100 microns to about 0.1 inches in diameter.
• During operation, themotor32 drives the main drive shaft36 (and flexible shaft end segment102). Referring toFIG. 20, thefirst gear320 is fixed to themain drive shaft36, while thesecond gear322 is fixed to thesaw shaft116. Thegears320,322 are preferably configured to step down rotational speed of thesaw shaft116 compared to themain drive shaft36.
• Referring toFIG. 23, as themotor32 drives theimpeller100, theimpeller100 rotates to generate airflow. This airflow creates a vacuum or suction pressure in thedebris accumulation chamber112 to draw debris from thedebris accumulation chamber112 into thevacuum conduits406. From thevacuum conduits406, the debris travels into the pressure-equalizingchamber96 and then through theinside plate120 of theimpeller100. Theimpeller100 then directs the debris out of theexhaust port95 and into thecollection bag300. InFIG. 22, the arrows show the direction of airflow and the direction of travel of the debris.
• Thesaw blade34 preferably has a plurality of teeth arranged circumferentially about a perimeter of thesaw blade34. Each of the teeth includes a flat section protruding radially outwardly from the main body of thesaw blade34 that has a width that generally approximates the width of the main body and is usually integrally formed with the main body out of a metallic material such as steel or composites thereof. In some embodiments, thesaw blade34 may be 10 inches or less in diameter, preferably between 6 inches and 10 inches, and more preferably between 6 inches and 8 inches. The width of thesaw blade34 is 3 mm or less, more preferably 1.5 mm or less, and most preferably between about 0.2 mm and 2.0 mm. Other embodiments may have varying sizes depending on the particular application or material to be cut.
• Each of the teeth has a kerf face that defines the kerf formed by thesaw blade34 during cutting. The blade's kerf face can take on many different shapes depending on the particular cutting application. In some embodiments, the kerf is 2 mm or more, while in other embodiments, the kerf is 2 mm or less. In one particular embodiment, the kerf is about 2 mm. In some embodiments carbide tips define the blade's kerf face, with the carbide tip fixed to the flat section in a conventional manner, such as by welding, adhesive, etc. A gullet is defined between the teeth. The gullet for a saw blade of about 10 inches in diameter or less is preferably less than 1 inch, more preferably less than 0.75 inches, and most preferably between 0.25 inches and 0.75 inches. For larger diameter saw blades, the gullet may be deeper.
• Each of the teeth may also include an embossed portion on opposing sides of the flat section that preferably extends from the carbide tip onto the main body of thesaw blade34. The height of the two embossed portions and width of the flat section in total preferably equal or are less than the kerf width of the teeth, more preferably less than about 95% of the kerf width of the teeth. The maximum height of each of the embossed portions in one embodiment may be 1 mm or less, more preferably 0.5 mm or less, and most preferably between 0.1 mm and 0.5 mm. In different applications, the height may differ.
• The dimensions of the various elements can be varied according to the uses and designs of the cuttingdevice30. For example, thedebris accumulation chamber112 may be from 0.5 inches to 10 inches in width. In some embodiments, theupper enclosure110, blade window132,side window160, and bellows180 may be unitary and formed in one-piece of plastic. Themotor casing38,vacuum housing90, andupper enclosure110 could also be formed in one-piece and could be formed of metal, plastic, or any combinations thereof. Additionally, the vacuum conduits406 (also referred to as debris carrying ducts406) could be integrated into a single duct (not shown) partitioned into separate paths to accomplish the same objectives as the present invention.
• As additional enhancements, lighting could be provided inside thedebris accumulation chamber112. Referring toFIGS. 13 and 13C, one ormore LEDs645 could also be positioned inside thedebris accumulation chamber112 and actuated by aseparate switch650. InFIG. 13, theLEDs645 are mounted inside theupper enclosure110 on the front side.Additional LEDs645 could be mounted on the opposite side of the upper enclosure110 (seeFIG. 13). The LEDs could be glued to theupper enclosure110, snap fit into sockets integrally formed in the upper enclosure, or otherwise fastened to theupper enclosure110 using screws, rivets, and the like. TheLEDs645 could be configured to automatically operate (light up) when themotor32 is actuated byswitch44, or could be separately operated by switch650 (seeFIG. 13C). Further, alaser guide700 could be incorporated in thecutting device30. InFIG. 13, thelaser guide700 is mounted to an outside of theupper enclosure110 along theupper shoulder155. Like the LEDs, thelaser guide700 could be configured to automatically operate when the motor is actuated byswitch44, or could be separately operated byswitch702. Thelaser guide700 could also be separately battery powered.
• While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed herein, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (15)

1. A cutting device comprising:

a material cutting blade;

a shroud which at least partially encloses the blade and relative to which the blade is supported for relative movement;

a debris accumulation chamber within the shroud in fluid communication with the blade and into which material debris generated by the blade during cutting is received;

a source of vacuum in fluid communication with the debris accumulation chamber;

a pressure equalization chamber in fluid communication with the source of vacuum;

a plurality of vacuum conduits extending between the debris accumulation chamber and the pressure equalizing chamber, each conduit having an inlet and an outlet, the debris accumulation chamber having an opening into a conduit inlet, the pressure equalization chamber having an opening into a conduit outlet;

wherein airflow induced by the source of vacuum is drawn from the conduit inlets to the conduit outlets, material debris received in the debris accumulation chamber carried by the induced airflow toward the vacuum source and the pressure equalization chamber.

2. The cutting device ofclaim 1, further comprising a vacuum housing having an exhaust port from which the induced airflow and material debris carried thereby exits the vacuum housing.

3. The cutting device ofclaim 2, wherein the source of vacuum is contained in the vacuum housing, and the induced airflow and material debris carried thereby is expelled from the exhaust port under a pressure greater than the pressure in the pressure equalization chamber.

4. The cutting device ofclaim 2, further comprising a collection container attached to the exhaust port and into which the induced airflow and material debris carried thereby is received, material debris received in the collection container retained therein.

5. The cutting device ofclaim 4, wherein the collection container is a collection container having a wall through which the induced airflow received thereby passes.

6. The cutting device ofclaim 5, wherein the collection container includes a porous inner container disposed within a porous outer container, the porosity of the inner container being less than the porosity of the outer container.

7. The cutting device ofclaim 1, wherein each outlet of the plurality of vacuum conduits opens individually into the pressure equalization chamber.

8. The cutting device ofclaim 1, wherein the inlets of the plurality of vacuum conduits are sequentially positioned along the path of blade travel within the shroud.

9. The cutting device ofclaim 8, wherein the blade is a circular saw blade rotatably supported within the shroud, the perimeter of the saw blade having a circumferentially distributed plurality of teeth, the inlets of the vacuum conduits positioned at locations on the shroud that are sequentially passed by each saw blade tooth.

10. The cutting device ofclaim 9, wherein the shroud substantially surrounds an upper portion of the circular saw blade and further comprising:

a lower blade guard connected to the shroud, the lower blade guard having movement relative to the shroud between an extended position in which it substantially surrounds the perimeter of the lower portion of the saw blade, and at least one retracted position into which it is received in the debris accumulation chamber and at least partially exposes the perimeter of the lower portion of the saw blade, the lower blade guard having a surface in which is provided at least one aperture that is moved substantially into alignment with a vacuum conduit inlet in a retracted position; and

wherein material debris generated by the blade during cutting is carried with the induced airflow into the conduit inlet from a location between the saw blade perimeter and the blade guard through the aperture substantially aligned with the conduit inlet.

11. The cutting device ofclaim 1, further comprising:

a deck plate through which the blade extends and to which the shroud is connected;

a base plate attached to the deck plate and through which the blade extends, the base plate being positioned between the deck plate and a material-engaging portion of cutting blade;

the shroud and the base plate having selective cut depth positions in which the distances from the base plate to which the material-engaging portion of cutting blade extends are varied;

the shroud and the base plate having selective cut angle positions in which the relative angle between the base plate and the material-engaging portion of cutting blade is varied;

wherein the blade is disposed in a space defined by a surrounding wall extending between the base plate and the shroud that is substantially sealed against air leakage through the wall, throughout the operating ranges of cut depth and cut angle positions.

12. The cutting device ofclaim 11, wherein substantially all of the air drawn by the vacuum source into the debris accumulation chamber substantially solely through an opening in the base plate through which the blade extends.

13. The cutting device ofclaim 11, wherein the surrounding wall includes a expandable first bellows located between the deck plate and the shroud, the first bellows being correspondingly expanded and compressed between different cut depth positions with corresponding relative movement between the deck plate and the shroud.

14. The cutting device ofclaim 11, wherein the base plate and the deck plate are pivotably attached to each other, and the surrounding wall includes a expandable second bellows located between the deck plate and the base plate, the second bellows being correspondingly expanded and compressed between different cut angle positions with corresponding relative movement between the deck plate and the base plate.

15. The cutting device ofclaim 11, wherein the surrounding wall includes a transparent window located between the deck plate and the shroud, the cutting blade and material being cut visible to an operator through the window during cutting operations.

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