Abstract: A saw blade preventing "fluff" or "return" of fibers from occurring when used to cut wood or the like object and rendering any finishing work unnecessary is formed with a unique combination of cutting teeth and biting teeth, the biting teeth being disposed, on a cut path mainly by means of the cutting teeth, either on top surface of or in front of each cutting tooth in cutting direction of the saw blade and to have a smaller width than the cutting teeth, for realizing a biting operation by the biting teeth and the cutting operation by the cutting teeth in the same sawing step.

Abstract: A depth adjuster for a rotary tool such as a screwdriver having a tool bit projecting through a nose provided at the front end of the rotary tool. The depth adjustor comprises a locator sleeve mounted on the nose to project on the front end of the tool in such a manner as to surround the tool bit. The locator sleeve has an internal thread engaged with an external thread on the nose so as to be axially movable relative to the nose and the tool bit as the sleeve rotates about the nose. A lock ring is fitted on the nose to be rotatively fixed but axially movable relative thereto. The lock ring is biased towards the locator sleeve by a spring for locking engagement into the locator sleeve so as to rotatively fix the locator sleeve around the nose, whereby retaining the locator sleeve at a desired axial position relative to the nose.

Abstract: A keyless chuck for a rotary tool comprises a chuck body which is adapted to be coupled at its one end to a drive spindle of a drive source and coupled at the other end to a tool bit for establishing a driving connection from the drive source to the tool bit. Relatively rotatable to the chuck body is a sleeve ring which is operatively connected to a set of gripping jaws for tightening the gripping jaws on the tool bit upon being rotated in one direction and loosening the same upon being rotated in the opposite direction. A one-way clutch is provided to rotatively fix the sleeve ring to the chuck body when the chuck body is driven to rotate in the direction of turning the tool bit reversely.

Abstract: The electric blower comprises an impeller of the centrifugal type driven by a motor, a diffuser having a plurality of divergent passages into which air flow discharged from said impeller flows, an air guide having a return passage subsequently directing said air flow from said divergent passages into the interior of said motor, and a casing housing therein said impeller, said diffuser and said air guide. Each guide wall of said air guide defining said return passage includes an inner guide wall section, an outer guide wall section and a space interposed between each inner guide wall section and the corresponding outer guide wall section, an opening being formed at the inner terminal end of each space.

Abstract: An upright vacuum cleaner includes a floor nozzle having a rotatable brush housed therein for operative contact with a surface to be cleaned, a main cleaner assembly coupled with the floor nozzle and accommodating a motor-driven fan having a motor shaft and a filter therein, a flexible power transmitting shaft for transmitting rotative power from the motor-driven fan to the rotatable brush along a power transmitting path between the motor shaft and the rotatable brush, and an intermediate power transmitting mechanism including a torque limiter mechanism disposed in the power transmitting path for cutting off power transmission from the motor shaft to the rotatable brush when the rotatable brush is subjected to a torque greater than a preset torque.

Abstract: An apparatus for effecting forced circulations of two separate fluids through separate fluids paths provided therein and, simultaneously, heat-exchanging between the fluids in a single unit is disclosed. It includes an impeller having a concentric corrugated zone made of a thin sheet material of good heat-conducting property, supported by a central disk member and an annular peripheral member, along both side of which flows of separate fluids are created, when the impeller is rotated. The heat-exchanging between the fluids each having a temperature difference with respect to the other is performed through the corrugated zone which the fluids are propelled through said paths.

Abstract: There is disclosed an electric blower assembly provided with an air guide structure designed such that the current of air expelled from a rotating impeller under the influence of centrifugal force is guided to the body of an electric motor while being accelerated. The air guide structure comprises an air guide block having front and rear compartments. The front compartment includes a plurality of volute chambers designed such that, during flow of air within the volute chambers, the dynamic pressure can be converted into static pressure. The flow of air under the static pressure is subsequently guided at a relatively low pneumatic velocity into the rear compartment and then into the body of the motor to cool the latter. The air used to cool the motor is thereafter exhausted to the outside of the motor.