Abstract: A cover to be disposed over a substrate processing apparatus is provided. The cover includes a material capable of being tuned between an opaque state and a transparent state. Being tuned closer to the opaque state limits an amount of light capable of passing through the tunable cover and into the substrate processing apparatus during substrate processing. Being tuned closer to the transparent state allows viewing into the substrate processing apparatus without removing the cover.

Abstract: A table tool includes one or more tool members disposed in a table, and a shield movably secured on the table. The shield may be moved toward and away from the tool members together with the work pieces for shielding the tool members and for dust collecting purposes, and for preventing the tool members from hurting the workers and the other people. One or more guide members are slidably secured on the table. A housing is secured on the guide members. The shield is pivotally secured to the housing for rotating toward and away from the tool members.

Abstract: A sanding disc particularly useful for smoothing drywall. The sanding disc includes a circular abrasive disc having an abrasive surface, and a circular foam disc smaller in diameter than the abrasive disc which is co-axially adhered to the surface of the abrasive disc opposite its abrasive surface. The abrasive disc has a circular central portion along which the surface defined by the abrasive is generally planar, and has an annular peripheral portion extending from its central portion to its peripheral surface along which its surface defined by the abrasive is generally cylindrically convex to position the peripheral surface of the abrasive disc in a plane passing through the foam disc.

Abstract: An electrical hand tool is proposed, whose handle, with is rotatably maintained on the motor housing, and has a maintenance opening. By means of this, the structural length of the hand tool is reduced, servicing is simplified and the production costs are lowered.

Abstract: The invention relates to an improved recovery system for blasting works, comprising a space below a perforated floor of the blasting works for receiving the blast material, and suction channels (21) for leading the blast material from the space below the floor to a classifier by using a blower; the recovery system comprises at least one elongated, substantially horizontal chute (17) opening upwards and arranged into the said space, the chute comprising two side walls (18, 19), and an elongated cover element (20) with two elongated free side edges (22, 23) arranged over the chute; the chute (17) and cover element (20) form between them a discharge channel (21) for the blast material; in addition, the system comprises pneumatic cylinders (26) for moving the cover element (20) in vertical direction between a lower and a raised position so that in the lower position, the side edges (22, 23) of the cover element engage the side walls (18, 19) of the chute and, in the raised position, the side edges (22, 23) of the

Abstract: A protection device (D) for the driving mechanism of a mobile element (O) against the cuttings of a machine tool includes a driving section (P1) and a machining zone (P2) separated by a protection wall. The protection wall is constituted by a plate (100) having a free translational motion on a disk (200) rotating freely with respect to the wall. A first displacement window (210) in the disk (200), and a second displacement window (310) in the wall are provided wherein both displacement windows (210 and 310) are arranged with respect to each other in such a way that the translational displacement of the plate (100) and the rotation of the disk (200) occlude the opening of both displacement windows (210 and 310).

Abstract: A dust shroud for use with a vacuum source and an abrading machine having a rotating abrading wheel includes a dust shroud housing adapted to be connected to the vacuum source and mounted to the abrading machine. The dust shroud housing includes a front wall with a front opening through which the abrading wheel may be accessed. A sliding door is slidably mounted to the front wall of the dust shroud housing for selectively covering the front opening.

Abstract: A tool for the removal of paint and putty includes a semi-circular assembly housing including a semi-circular rigid collar. The tool also includes a disk-like abrading assembly rotatably and co-axially mounted within the semi-circular collar of the housing, the assembly including rigidly disposed abrading elements projecting both axially and radially, the assembly defining a plane of rotation. The tool further includes a motor for high speed rotation of the assembly, the motor located externally of the housing. The tool also includes bearings for establishing a fixed axial cutting depth relative to a primary work surface positioned thereagainst, in which the bearings function as a buffer between the abrading assembly and the work surface to thereby improve control and mobility of the assembly relative to the primary work surface. A platform is disposed between the assembly housing and the motor, in which the platform is preferably co-planer with the plane of rotation of the abrading assembly.

Abstract: A portable, self-contained sand blaster including a cabinet and accessory end caps. The caps include a solid end wall, an extension box for treating larger parts in the cabinet, a softboot with drawstring closure affixed about parts to be treated, and a softboot with a magnetic opening for attachment to rusted, relatively flat surfaces. The base is wheeled and has controls, a vacuum for dust, a sand supply, and a blast cabinet on top; the base includes connectors for hookup to electric power and a source of compressed air. A media filter screens out rust particles form the media.

Abstract: A dust protection cover for a rotary grinding tool and having a base (1, 11, 21) fixedly securable with the tool housing (10) a substantially circular cover body (2, 12, 22) connectable with the base (1, 11, 21) for completely circumferentially covering the grinding disc (4, 14, 24) securable at the free end of the output shaft of the tool drive motor, and displaceable between a operational position, in which the cover body completely covers the grinding disc, and a release position in which the cover body exposes a portion of a grinding disc circumference, and a connection element(s) projecting from a side of the base (1, 11, 21) adjacent to the tool housing for securing the cover body (2, 12, 22) to the base (1, 11, 21) in the release position of the cover body.

Abstract: A concrete saw (10) includes a cutting assembly having a high compression diesel motor (38) mounted on a carriage (40) in turn slideably mounted in a frame (22) in turn pivotally mounted to parallel rails (14) of a chassis (12) moveably supported on the concrete surface by wheels (18, 20). Concrete slurry hardened on two pairs of UHMW slides (30, 44) provided between the sliding surfaces of the carriage (40) and the frame (22) will break away and fall from the slides (30, 44) when the belt tension is adjusted. A guard (58) prevents entry of concrete slurry to the belt drive and includes a housing (66) having a U-shaped wall (68) which closely conforms to the bottom periphery of the sheave (36) of the belt drive.

Abstract: A removable guard for a hand-held power tool. The guard is configured to cover an area proximate a spindle assembly of the tool between the spindle assembly and a user of the tool. The guard is further configured to be securely mounted to a semi-elastic lower bearing housing supporting the spindle assembly of the tool. The guard, when mounted to the semi-elastic lower bearing housing of the tool, and when in use during operation of the tool, must remain functional under conditions of flying debris, such as under conditions of an exploding, rotating abrasive grinding wheel mounted on the spindle assembly of the tool. The guard includes a clamp ring depending from a guard hood.

Abstract: A ventilated platen/polishing pad assembly for chemical mechanical polishing copper conductors on a semiconductor wafer is disclosed. The ventilated platen is constructed by a platen having a multiplicity of apertures through a thickness of the platen, and a polishing pad that has a multiplicity of apertures for fluid communication with the multiplicity of apertures in the platen such that a gas can flow through the ventilated platen and the ventilated polishing pad to mix with a polishing slurry solution dispensed on top of the polishing pad. When an oxidizing gas is mixed with the slurry solution, the mass transfer process during the chemical mechanical polishing can be improved and thus improving the polishing uniformity of the copper surface.

Abstract: An attachment for a hand cutting tool having at least one rotating blade, the attachment including a portable device attachable to the hand cutting tool for producing a fog-like spray of water droplets near the rotating blade for moistening dust particles generated during cutting, and a hand tool including such an attachment. Preferably, the attachment includes a blade guard arranged to partially cover the rotating blade, a portable source of pressurized water which can be carried on the body of a user holding the cutting tool, and at least one nozzle mounted in the blade guard and coupled to the source of pressurized water for producing a fog-like spray of water droplets.

Abstract: An exhaust assembly of a sanding device includes a first passage and an extension tube which are respectively defined in a hosing of the casing of the sanding device. The hosing has an inlet and an outlet. The first passage communicates with the outlet and inlet, and the extension tube extends from the hosing. The extension tube is engaged with an annular cover which communicates with the sanding pad and has an exhaust tube. A control valve is rotatably received in the first passage to block or open the outlet or the extension tube. A bag or a vacuum cleaner can be connected to the exhaust tube of the annular cover to collect sanding powder or sanding debris.

Abstract: A finishing orbital sander (1) includes a main body (2) and a base (12) provided below the main body. Provided between the main body and the base are a plurality of foot assemblies (22). Each assembly in turn includes a cylindrical or columnar foot (23) made of aluminum and a pair of rubber O-rings (25) at both ends of the cylindrical foot. Each foot additionally includes reduced diameter sections (24) at both ends, where the O-rings are disposed. The reduced diameter sections (24) are fitted in the O-rings and placed in recessed seats (26) provided in opposing surfaces of the main body (2) and the base (12), thus elastically supporting the aluminum feet (23) in the axial direction thereof. The axial dimension of each reduced diameter section (24) is made no longer than the thickness (i.e., the axial dimension) of the O-ring (25), so that the tip end of the reduced diameter section does not exceed or project from the axial outermost end of the O-ring.

Abstract: A key grinding duplicating attachment that includes a base with upright bearing supports juxtaposed which supports a horizontal guide bar transporting control housing assembly. Said assembly movement being slidable on a horizontal axis, swingable upward and downward in contact with top edge of the keys. Base solid mount angled vise support uprights with clamping vises juxtaposed for specimen and blank keys. The said transporting control housing assembly supports a modulate direct output rotary tool high speed high torque motor or an equivalent, profiled abrasive key grinder arbor assembly, a juxtaposed profiled stylus in line. An effortless means to produce usable duplicated keys continually.

Abstract: Manufacture of a polishing pad for polishing a semiconductor substrate, involves, transporting a backing layer to successive manufacturing stations, supplying a fluid phase polymer composition onto the transported backing layer, shaping the fluid phase polymer composition into a surface layer having a measured thickness, and curing the polymer composition on the transported backing layer in a curing oven to convert the liquid phase polymer composition to a solid phase polishing layer attached to the transported backing layer.

Abstract: A machine tool is provided, especially a multiple station grinding machine for the production of drill bits and similar elongate workpieces, which has at least one axially displaceable and rotatable workpiece holder which has its axial displacement and rotation drive in a sealed-off housing, at least one working tool arranged in a sealed-off working space, a sealing separation wall between the housing and the working space, at least one guide conduit arranged in sealing relationship in the separation wall for receipt of the workpiece holder, and guide elements for the workpiece disposed at the end of the guide conduit which extends into the working space.

Abstract: A grinding device includes a grinding wheel member driven by an output shaft of a motor. A drive transmission member transmits the driving force of the output shaft to a rotating shaft to operate a blowing member when the motor is actuated. A dust collecting member is disposed in the vicinity of the grinding wheel member for collecting dust during a grinding operation. An elongated hollow member is disposed between the collecting member and the blowing member so as to draw dust from the collecting member to the blowing member.

Abstract: A machine tool comprises a working area, closed by walls and a roof covering, in which a device for receiving a work piece is arranged, and a headstock with a main spindle is arranged, into which tools for machining the work piece can be clamped. Device and headstock are movable relatively to each other. In a front wall an opening lockable by a door leads into the working area. At least one part of the roof covering is movable between two positions in such a way that it locks the working area to the top in a first position and releases same to the top for loading in a second position.

Abstract: A machine tool includes a working table slidably supported on an upper portion of a base, and a protective cover rotatably secured to one or both of the ends of the working table with a pivot shaft. The protective cover is dependent downwardly when the protective cover is disengaged from the end portion of the base, and may be rotated to move upward. of the upper portion of the base when the working table is moved inward of the upper portion of the base. The cover may thus be used to suitably cover and shield the space formed between the working table and the base.

Abstract: The present invention relates to a protective cover for at least one working part of a machine tool or similar machine, the machine part moving in a linear direction and the cover being designed to follow its movements so as to keep the corresponding zone inside the machine protected. The cover comprises a set of overlapping covering elements in the form of a first covering element that can be connected to the machine at the zone to be protected and a plurality of covering elements that move relative to each other and relative to the first covering element in the same linear direction as the working part of the machine moves. Each covering element has an opening through which a portion of the working machine part or its support can protrude outwards, the opening in the first covering element forming an area to be covered by the remaining covering elements, and the movable covering elements decreasing in size going from the inside to the outside.

Abstract: A hand tool is fitted with a fixed shield and a movable shield which is rotatably mounted around the fixed shield. The two shields are aligned with one another by each shield being keyed into a countersunk washer formed with an anchor slot for the fixed shield and a semi-annular guideway for the movable shield. A torsion spring normally biases the movable shield into a closed position about the fixed shield.

Abstract: A repair machine for compact disk is used for cleaning, maintaining, and repairing compact disks. The processing procedure is basically a mechanical method by: placing a scratched compact disk on a CD turntable of the repair machine, grinding it with a grinding wheel and dripping grinding agent on the grinding wheel continuously. The grinding agent is classified in three categories: coarse, middle, and fine (polishing), for trimming scratch to renew a marred compact disk.

Abstract: Abrading and cutting devices such as saws include waste containment systems and methods to improve removal of slurry or other contaminants from a work area during operations, and separation of slurry from a carrying medium such as air. A vacuum bar includes high and low vacuum openings to help focus flow and to conserve vacuum pressure. One opening faces the saw blade. A slurry containment and separation container includes walls and configurations for the inlets and outlets that enhance cleaner separation of the air and the slurry. Coolant is applied to the saw blade to make operation and cleanup more efficient. The vacuum generator can operate off of the power generated by the machine.

Abstract: A machining apparatus has a frame, a conveyor on the frame extending in a workpiece travel direction and adapted to support a flat workpiece, a tool mount displaceable on the frame transversely of the direction, a material-removing tool on the mount for machining the workpiece with generation of particles, and a drive roller engageable with an upper surface of the workpiece upstream of the tool for advancing the workpiece in the direction past the tools. A shield is provided above the conveyor extending transverse to the direction upstream of the tools and downstream of the drive roller. At least one actuator serves for pressing the shield against the workpiece between the tools and the drive roller during machining of the workpiece. Nozzles immediately adjacent the shield are connected to a supply of compressed gas for directing a gas current at the workpiece and blowing particles thereon downstream in the direction.

Abstract: An apparatus and method for re-surfacing compact discs. The method is a two-step method in which the disc to be re-surfaced is first placed on a shaft. A resilient pad supports an abrasive medium and is positioned so the abrasive medium overlaps only the protective layer of the CD. The disc and abrasive material are rotated in opposite directions at about the same speed to remove deeper blemishes in a wet operation. Subsequent polishing is accomplished in a similar manner using a polishing compound instead of an abrasive. The re-surfacing and polishing apparatus each have motor driven shafts which are parallel and spaced apart and support the CD and pad in a cabinet. A transparent cover extends across the top of the cabinet.

Abstract: A case for storing a grinding wheel which comprises an annular support member and a grinding means provided on the lower end face of the support member. The case includes a first case member and a second case member, the first case member and the second case member are connected to each other by a hinge member in such a manner that they can pivote relative to each other and selectively set to a close state for defining a closed storage space and to an open state for opening the storage space. A receiving means is provided on the first case member and a restricting means is provided on the second case member. The support member is held between the receiving means and the restricting means, and the grinding wheel is stored in the storage space, without allowing the first case member and the second case member to contact with the grinding means.

Abstract: A cover for a pad conditioning assembly for use in a chemical mechanical polishing apparatus and a pad conditioning assembly incorporating such cover are disclosed. The cover may be formed of a body portion with at least two boss sections and at least two locking tabs mounted in the boss sections. The cover provides a quick mount/dismount to a support plate of a pad conditioning assembly by engaging and disengaging the blocking tabs. The cover further provides the advantage that when a substantially transparent material is used in fabricating the cover, any malfunction or breakage of the components under the cover can be readily observed. The cover is further provided with an extended skirt section such that all the major components of the pad conditioning assembly can be shielded a slurry solution and cleaning fluids.

Abstract: A machining tool for dry processing includes an encapsulated workspace having arranged therein a workpiece support which is displaceable on a machine bed. The guide members of the workpiece carrier are arranged externally of the workspace, so that chip removal is not impeded by the workpiece support guide members.

Abstract: A canopy for a wet saw including a cover member adapted for extending between the motor portion and the water pan of the wet saw. The cover member has a main panel and a pair of opposed side panel. An upper edge of the main panel has a pair of tabs extending upwardly therefrom. Upper fastening means are coupled with the tabs of the upper edge of the main panel of the cover member and with the motor portion of the wet saw to facilitate securement of the cover member to the wet saw. Lower fastening means are coupled with the main panel of the cover member upwardly of the lower edge thereof and with the water pan of the wet saw to facilitate securement of the cover member to the wet saw.

Abstract: A cleaning apparatus having a housing, a motor, a battery, and a removable cleaning attachment. The housing comprising a rigid subassembly shell and a resilient cover. The cover is injection molded onto the shell to waterproof a majority of the shell. The shell has raised portions on its exterior that are used to position the shell in the injection mold. After molding is completed, the cover surrounds the raised portions, but does not cover them.

Abstract: A polishing apparatus includes a top ring for holding a workpiece to be polished on a lower surface thereof, a turntable having a polishing surface for polishing a surface of the workpiece held by the top ring, and a dressing tool for dressing the polishing surface of the turntable. The top ring is movable to a first maintenance position therefor, and the dressing tool is movable to a second maintenance position therefor. The top ring, the turntable, and the dressing tool are housed in a single chamber having a plurality of side faces. The polishing surface, the first maintenance position, and the second maintenance position are positioned closely to one of the side faces of the chamber. Such one side face serves as a maintenance face for approaching the polishing surface, the first maintenance position, and the second maintenance position for maintenance of the polishing surface, the top ring and the dressing tool.

Abstract: The present invention, a tool safety shield, comprises a clip with at least one shield. The clip further comprises vent ribs. The shield extension further comprises a vacuum port. Both one piece and two piece embodiments are disclosed. The tool safety shield is attachable to a tool or to an adapter from the tool to the tool safety shield.

Abstract: The invention relates to a method for producing sheets of polymeric surfacing, the sheets produced thereby, and the apparatus used to produce the sheets. The method includes providing a solid polymeric slab, and slicing the slab into sheets of surfacing. The sheets may include polymeric particles contained in a polymeric matrix. The particles may have a maximum linear dimension that is greater than the final thickness of the sheets, thereby resulting in an aesthetically pleasing “chunky” appearance. The apparatus used to slice the sheets produces a relatively smooth, uniform surface, and is capable of dramatically limiting the amount of variation in thickness within a finished sheet.

Abstract: The present invention provides a grinding apparatus for semiconductor wafers for preventing the silicon powder generated from the wafer grinding process and mixed with cooling water from contaminating height gauges of the grinding apparatus because the silicon powder is scattered toward them, and for preventing wear-down of the contact heads of the height gauges due to the abrasion with a wafer to be fixed on a spin-chuck and the spin-chuck.

Abstract: There is provided a structure for use in a power driven tool (1) for collecting dust generated by the operation of the tool. The structure includes: an outer housing; a commutation motor (5) disposed within the housing and including a main shaft (6) which has a tip end and a commutator (7) on the main shaft; a pair of brush assemblies (29) radially disposed around, and in contact with, the commutator of the motor; and a dust collecting fan (9) mounted on the main shaft of the commutation motor. The fan is disposed between the commutator and the outer housing. Also included are a dust intake passage (28) formed within the housing and having an intake (27) formed adjacent the location where dust is generated by the operation of the tool; a dust discharge passage (46) formed within the housing and having an outlet; and a dust chamber (43) formed substantially between the outer housing and the commutator for containing the dust collecting fan.

Abstract: A method and apparatus for a dust collecting work station that utilizes a positive pressure air flow to entrap particulate material from within the work station. The dust collecting work station is especially suited for use by dental technicians, goldsmiths and jewelers. The work station can be economically manufactured, operated with typically available compressed air supply, and can be constructed to fit upon a table top. The dust collecting work station includes a collection base with a back shield that together enclose a work area. A positive pressure air flow is provided to the work area for removing particulate material by impacting the particulate with the positive pressure air flow. A filter media positioned proximately to the collection base entrains the particulate material that is knocked down by the positive pressure air flow. The positive pressure airflow can be supplied by a nozzle located proximate to the face of a user or supplied by a nozzle located proximate to the back shield.

Abstract: A precision polishing apparatus has a first hermetically sealed chamber provided with polishing means, a third hermetically sealed chamber capable of communicating with the first hermetically sealed chamber through a second hermetically sealed chamber, first and second opening-closing means for alternately placing the first and the third hermetically sealed chamber in communication with the second hermetically sealed chamber, and atmosphere pressure control means for controlling the atmosphere pressure of the first and the second hermetically sealed chamber so that the atmosphere pressure of the first hermetically sealed chamber may become lower than the atmosphere pressure of the second hermetically sealed chamber when at least the first opening-closing means is opened.

Abstract: A dust collecting router for collecting dust and debris while using a router. The dust collecting router includes a housing with a passage therethrough with a pair of ends each having an opening into the passage. A motor is mounted in the housing and has a rotating shaft outwardly extending therefrom towards a first end of the housing. A cutting bit is coupled to a free end of the rotating shaft and outwardly extending through the opening of the first end of the housing. An impeller comprising a plurality of fan blades outwardly radiating from the rotating shaft of the motor. A collecting container is in communication with the opening of the second end of the housing.

Abstract: A disc sander having a scroll type vane pump embodied in a shroud enclosing the back side of a sanding disc. The inlet ports of the pump are coupled by a manifold to a location adjacent to the front face of the sanding disc at a location where the sanding dust and debris are generated. A tortious serpentine path is provided about the periphery of the pump housing which reduces pump noise and increases pump efficiency. The fins of the vane pump are provided on the back side of the sanding disc.

Abstract: A polishing apparatus 70 is used for polishing a workpiece such as a semiconductor wafer to a flat mirror finish by a combination of chemical polishing and mechanical polishing. The polishing apparatus includes a turntable 73 with a polishing 74 cloth mounted on an upper surface thereof, a top ring 75 for supporting the workpiece to be polished and pressing the workpiece against the polishing cloth, and a dressing tool 79 for dressing the polishing cloth on the turntable. The polishing apparatus further includes a cover 10 which covers an upper surface of the turntable for preventing liquid on the turntable from being scattered, and inserting holes 17 and 21 formed in an upper wall of the cover for inserting the top ring and the dressing tool therethrough.

Abstract: A belt sander stabilizer for keeps a sander body and the portion of the sander belt that makes contact with the surface being sanded level during operation. The belt sander includes a shield having an upper panel and a pair of lateral sides that downwardly extend from side edges of the upper panel. A pair of support arms are pivotally coupled to the lateral sides and are adapted for engaging a surface to be sanded.

Abstract: A sanding apparatus is disclosed which includes a motor and mechanical drive system for imparting rotational and oscillator motion to an output shaft thereof. The motor shaft extends upwardly through a worktable. In one embodiment, the sanding apparatus is convertible between two or more modes of operation. In a spindle sanding mode, a sanding spindle is coupled to the motor output shaft, such that the spindle rotates and oscillates with respect to the worktable. In a belt sanding mode of operation, a belt sanding belt/pulley assembly is attached to the motor shaft. The belt/pulley assembly includes a drive drum and a driven drum about which a sanding belt is entwined. When operated in belt sanding mode, the entire belt/pulley assembly, including the drive drum and the driven drum oscillate up and down with respect to the worktable. In an edge sanding mode of operation, the worktable is articulated so that at least a portion thereof is angularly adjustable with respect to the belt/pulley system.

Abstract: A grinding wheel shield for a semiconductor wafer edge grinding machine formed with a flat upper surface having a central aperture therein for accommodating the grinding wheel shaft and motor of the grinding machine on which the shield is installed, an open keyway slot leading from the central aperture to an adjacent edge of the shield, a depending flange extending from at least a portion of the periphery of the upper surface, and at least one positioning member projecting from the depending flange, the shield being a unitary member machined from a single block of resilient polymeric material, and a sheet of resilient material disposed on top of the flat upper surface with an opening aligned with the central aperture of the shield and a slit extending from the opening over the keyway slot to the edge of the shield such that the sheet forms at least one flexible flap over the keyway slot.

Abstract: A fluid deflection device for use in a work piece holder during a semiconductor wafer grinding process is disclosed. The fluid deflection device includes an annular, upstanding splash fence, and an attachment portion associated with the splash fence and configured to attach to the work piece holder, thereby to hold the splash fence in a position to inhibit fluid from flowing between rotatable and non-rotatable parts of the work piece holder.

Abstract: A suction device for a hand-held tool having a plate-like working tool, the section device including a hood-shaped housing covering a rear side of the tool (4) and partially a working tool circumference and connectable with a device for creating vacuum, and a protective screen (3) formed of a flexible material and extending along a circumference of a free end surface of the housing (2) and projecting axially above the free end surface, with the protective screen (3) having a plurality of slots (31) distributed along a circumferential extent of the protective screen (3) and opening toward a free end of the protective screen (3).

Abstract: A grinding tool accessory for containing and removing dust formed by a grinding disk comprises: a flexible housing adapted for mounting on the grinding tool and defining a first chamber for collecting the dust prior to removal, the housing having an edge spaced from an outer perimeter of the grinding disk and defining an annular gap; the housing having an outlet adapted for connection to a source of vacuum and a dust collector; a brush extending from the edge and together with the grinding disk defining a second chamber, the brush having bristles with different lengths dimensionally related to the gap, dust being drawn from the second chamber into the first chamber through the gap and thereafter into the dust collector by the vacuum; and, the housing having at least one sealable hole to adjust the vacuum for optimizing containment and collection of the dust as the grinding tool is moved over flat and contoured portions of a work surface.

Abstract: A motorized finishing machine has a rotatable guard system enabling it to finish concrete surfaces next to walls, posts, conduits, or other obstacles. Deployed as a concrete trowel, the machine comprises an internal combustion motor that powers a gearbox to revolve a downwardly projecting rotor. Numerous radially spaced-apart finishing blades controlled by the rotor frictionally contact the concrete surface being treated. A protective guard, which circumscribes the rotor, is rotatably suspended by a plurality of rollers. The guard, which is shaped somewhat like a truncated cone, comprises an inner ring coaxially secured above a larger diameter, outer ring. Radially spaced apart spokes extend between the upper and lower rings and brace the guard. The bearing-equipped rollers mounted by radially, spaced-apart arms have upper and lower flanges. The inner guard ring is captivated between the rollers, and it is vertically constrained between the roller flanges.