Abstract: A dust collection system for a power tool which comprises a drive unit, a body, a tool support, and a collection chute. The body defines an inlet opening and a discharge opening, the body having a communicating conduit located within the body which communicates the inlet opening with the discharge opening, and the body supporting the drive unit. The tool support is operably connected to the drive unit and defines a collection aperture, an exit opening which communicates directly with the inlet opening of the body during operational movement of the tool support, and a suction cavity in communication with both the collection aperture and the exit aperture.

Abstract: A blower is provided having a plurality of tubular nozzles removably attachable to the blower enabling an operator to easily vary the velocity and air discharge pattern. The blower forms part of an operator carried power tool having a drive motor spaced from the blower assembly by a tubular boom containing a drive shaft. The blower comprises a blower housing having an axial air inlet and an air outlet defined by a tubular section. An impeller is pivotally mounted within the blower housing and driven by the drive shaft. As the impeller is rotated, air is drawn through the air inlet and discharged through one of a plurality of tubular nozzles mounted on the blower housing tubular section. Tubular nozzles have varying geometries to conveniently vary the discharge air pattern.

Abstract: Method and top blowing lance for decarburization refining chromium molten ferrous metal in which dust formation and chromium loss due to oxidation are suppressed and high productivity is achieved. Decarburization of molten ferrous metal is achieved by blowing gaseous oxygen into the molten metal in a refining furnace provided with a top blowing lance having a plurality of gas blowing nozzles at the tip of the lance. The gas blowing nozzles include at least one sub-nozzle provided at or near the lance axis and a plurality of main nozzles at an outer section of the lance. Blowing refining is carried out with oxygen flow from a plurality of the main nozzles at a flow rate higher than that from the sub-nozzle(s), when the carbon content in the molten metal is about 1 wt % or more.

Abstract: A method of decarburizing refining molten steel containing Cr in such a manner that oxygen gas, inert gas or a mixture of inert gas and oxygen gas is blown to the surface of bath of molten steel containing Cr in a refining chamber and to a position below the surface of the steel bath. Inert gas is blown to the surface of the steel bath, and oxygen gas, the inert gas or a mixture of oxygen gas and inert gas is blown below the surface of the steel bath in a portion of or all of an overall period in which the concentration of C in the molten steel is in a range of 1 wt % and 0.05 wt %. Slag and molten steel are stirred so as to cause Cr.sub.2 O.sub.3 in the slag and C in the molten steel to positively take part in a reaction represented by expression (1) below:Cr.sub.2 O.sub.3 +3C.fwdarw.

Abstract: A router for engaging a workpiece to be cut has a housing and a motor operable to rotate a drive shaft. A first fence is adjustably secured to the housing, and has a first planar surface oriented substantially parallel to the drive shaft axis. The first fence is adjustable to move the first planar surface toward and away from the drive shaft axis. A second fence is slidably attached to the first fence. The second fence has a second planar surface oriented substantially perpendicular to the drive shaft axis, and has an opening for receiving the bit therethrough. The second fence is slidable to move the second planar surface toward and away from the drive shaft to allow the bit to be plunged through the opening to cut the workpiece. The first and second planer surfaces are sufficiently sized so that either the first or second planer surface can be used as a base for the router with the router center of gravity located directly above the planer surface that is used as the router base.

Abstract: A router attachment is provided for converting a small hand-held rotary cutting tool into a miniature router. The attachment has a base having a planar lower surface, a central aperture, an upright column and a handle. A tool holder slidably mounted on the upright column is provided with a clamp for affixing the rotary cutting tool thereto. A height adjustment mechanism enables the user to adjust the height of the tool holder relative to the base planar lower surface and a lock mechanism releasably locks the tool holder to the base column during use.

Abstract: A liquid crystal display device comprising: (a) a liquid crystal layer arranged between substrates each having an electrode; (b) a pair of polarizers arranged so as to sandwich the liquid crystal layer; (c) a birefringent medium arranged between the liquid crystal layer and at least one of the polarizers, when a voltage is applied so that liquid crystal molecules at boundary regions facing said substrates have different tilt angles from other molecules, retardation in said birefringent medium being equal or close to remaining retardation due to the liquid crystal molecules at boundary regions, and the slow axis of said birefringent medium being set for an angle to compensate for said remaining retardation; and (d) control means for changing transmission of said liquid crystal layer by applying voltages of two or more values between said electrodes.

Abstract: The present invention provides a liquid crystal display apparatus having preferable viewing performance with low cost. A display in a dark state is performed with an applied voltage which makes a square sum of deviation of normalized Stokes parameters S1', S2' for light transmitted through a twisted nematic liquid crystal layer having wavelengths, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm from their regression line 51 equal to or less than 0.05, a slow axis 52 of an optical compensation layer crosses over perpendicularly with the regression line 51 on a Poincare sphere sighted from a S3' axis direction, a phase difference of the optical compensation layer, .delta.(.lambda.), is defined by the following equation;.delta.(.lambda.)=180n.+-.arctan((S1'cos2.theta.-2S2'sin2.theta.)/S3')and an absorbing axis 53 of a higher polarizer is set so as to cross over either of two points, A and B, at which the regression line crosses over the equator on the Poincare sphere.

Abstract: A removable working tool assembly that can be used with a power driven tool having a drive shaft. The removable working tool assembly includes a drive member which can operably connected to the drive shaft and a support member having a tool surface. One of the drive and support members defines a male connection mechanism while the other one of the members defines a female connection mechanism such that the members can be simply connected and disconnected without the need for tools or any other fastener elements. This allows various support members to be easily changed to facilitate the use of different tool surfaces such as sanders, grinders, scrapers or the like.

Abstract: A palm grip random orbital sanding machine having a housing and an electric motor disposed in the housing which drives an attached platen along a random orbital path. An exhaust fan disposed in an exhaust chamber produces an air flow from the vicinity of the platen out through an exhaust port. The housing has a pair of longitudinal slots provided on opposite sides thereof which removably receive the legs or side members of a U-shaped debris container. Each side member of the debris container has an entrance port coincident with the exhaust port of the exhaust chamber, and means for filtering the debris from the air flow exiting the side members. The commutator and brushes of the electric motor are disposed intermediate the longitudinal slots and the brushes are disposed parallel to the longitudinal axis of the sanding machine.

Abstract: A clamp (20) and method for making the same are disclosed. The clamp (20) has a pair of jaws (42,44), a pivot (46) and an actuator (48). Each of the jaws (42,44) has a distal end (54,56) and a clamping end (50,52). The jaws (42,44) are pivotally connected by the pivot (46) such that the actuator (48) can displace the distal ends (54,56) relative to one another causing the clamping ends (50,52) to pivot together to retain the end of a blade therebetween. Preferably, the actuator (48) is a thumbscrew and the pivot (46) is a pivot pin cooperatively retained by respective pivot apertures (60,62) located in each of the jaws (42,44). Alternatively, the pivot (46) may be tenon (164) formed on one jaw (144) and a mortise (162) formed in the other jaw (142), the tenon (164) being pivotally retained within mortise (162). The clamp (20) is manually operable to clamp the scroll saw blade without the use of separate tools such as a screw driver or an Allen wrench.