Abstract: A corded/cordless dual-mode power-operated device, such as a household vacuum cleaner, can be operated in corded mode from a conventional power source and in a cordless mode using energy provided from an internal rechargable battery and which includes an internal battery charger for recharging the battery when the device is in its corded mode. The internal charger includes a voltage converter that converts input source current to a relatively high DC current that is chopped at a comparatively high frequency, e.g., 25 KHz, by switching devices. The high-frequency, high voltage current is presented to a step-down transformer with the stepped-down output rectified to provide a low-voltage DC suitable for recharging the internal battery when the device is in its corded mode. The voltage converter advantageously provides for the high efficiency conversion of the input energy to meet the charging current demands of the internal battery in a physically compact device.

Abstract: A radial arm saw includes a saw assembly pivotally mounted to a support unit which, in turn, is mounted to a wall or other support structure. The saw assembly includes a column that is connectable at one end to a saw table frame or the support unit so as to be affixed in upright operative position during operation and disposed during non-operation in a lateral, storage position. A radial arm and saw unit are supported from the other end of the column. Preferably, the column is pivotal between a lateral stored position and an upright operative position. Also, the saw assembly is pivotal relative to the support unit between a vertical stored position and a horizontal operative position. A leg locking sleeve may be released to deploy the saw assembly from its stored position into its operative position. The support column may be detachable to shift the radial arm saw between operative and stored positions.

Abstract: A saw blade assembly comprises a laminated structure of three side-by-side parallel strips, one two or all of which may have spaced teeth formed along one edge. Where only one strip has teeth, it is sandwiched between the two other strips and the teeth are of triangular shape when seen in plan and are bevelled on both edges to produce pointed tooth tips. Where two strips have teeth, the strips are arranged one on each side of a center strip. Again, the teeth are of triangular shape when seen in side elevation and are contoured to form pointed tips. The roots of the teeth on one strip are spaced laterally from the roots of the teeth on the other strip because of the presence of the center strip. In another form, each strip has teeth along one edge, the assembly thereby providing three parallel, side-by-side rows of teeth. The teeth are of triangular shape when seen in side elevation and are contoured to form pointed tips.

Abstract: A hand-held power cutting tool has a generally cylindrical casing, which can be grasped in the palm of one hand, and whose rear portion housed an electric driving motor disposed in the casing with its axis of rotation lying along the longitudinal axis of the rear portion. Reciprocated by the motor via a drive transmission system is a cutter carrier mounted for reciprocatory movement in a bearing support structure. The cutter carrier carries a clamp by which a cutter is attached to the carrier. The carrier is reciprocated at a rate of between 4,000 and 12,000 movements per minute and with a stroke of from 4 to 12 mm for rapid cutting of thin material. The cutter may have a generally U-shaped blade.

Abstract: In a housing (22) for a right-angle grinder (20), a pair of clamshell sections (24) and (26) are joined along a midplane (28). The interior of the housing (22) is formed with a motor case (34) and a gear case (36). Clamshell section (26) is formed with a rib (76) in a peripheral edge (72) thereof and is nested in a groove (58) formed in a peripheral edge (56) of clamshell section (24) to form an interlock for the housing (22). Slots (78) and (80) are formed transversely through the rib (76) along two spaced paths of the interlock to preclude a flowable lubricating substance from creeping from gear case (36), along the two spaced paths of the interlock to the motor case (34).

Abstract: A hand-held power file has an abrasive belt trained around spaced apart drive and idler pulleys. The drive pulley is located in a chamber and mounted upon an armature shaft of an electric motor. Also mounted upon the armature shaft is a fan that, in use, creates an air flow through the chamber to remove dust debris from the belt. The abrasive belt extends through an opening at the front of the tool's housing and which also serves as an inlet for the air flow. A bag, for receiving dust entrained in the air flow, is supported by outer and inner supports and fits over an outlet nozzle extending from the chamber.

Abstract: A fixing in a wall is made by drilling a hole, inserting the pin of a nozzle mounted on a hot melt gun into the hole and injecting molten polypropylene into the space between the pin and the hole. The polypropylene is allowed to solidify and the nozzle is removed leaving a wall plug ready for the insertion of a screw. Three embodiments of a nozzle especially adapted for use in this process are described. nozzle has a hollow screw-threaded base with a pin extending forwardly therefrom. Passageways in the base each communicate at one end with the interior of the base and at another end externally of the base and the pin in the vicinity of the junction between the pin and the base. A flexible seal is slidably mounted on the base and resiliently biased towards the pin.

Abstract: A rotary hammer has a reciprocating piston of a pneumatic impact mechanism driven from a rotatable drive shaft. A coupling element is fixed on, and a drive element slidably mounted on, the drive shaft. These elements have interengageble tapered coupling surfaces and are biased apart by a spring therebetween. The drive element is disposed forwardly of the coupling element and is slidable rearwardly to drivingly engage the coupling surfaces for transmitting drive to the piston. The relative disposition of the drive and coupling elements causes reaction force on the piston, consequential in use upon generation of percussive blows, to urge the drive element into intensified engagement with the coupling element.

Abstract: A cutterhead for a power planer has an elongated core with threaded holes for releasably mounting a pressure plate with a cutting blade being clamped between the pressure plate and the core. The core has a support surface contacted by the cover portion, a contact surface contacted by the pressure plate, and a transition surface therebetween. The support surface is inclined to the contact surface at a angle of more than 180 degrees and less than 270 degrees. This arrangement helps compensate for tolerances associated with the securing screws, and reduces any tendency for imbalance in the cutterhead when rotating. A pair of cover portions may support opposite sides of the cutting blade adjacent its cutting edge. The cutting blade may be a profile blade.

Abstract: A worktable has a table top with a slot for reception of a saw blade of a hand-held circular saw when mounted below the table top. Two rip fences mounted on the table top are separately slidable in parallel adjusting slots for adjusting independently the position of each fence. A hole in the table top adjacent the middle of the saw blade slot accommodates a cutting tool of a portable router when mounted below the table top. A router guard may be pivotally attached to a raised support structure between the rip fences. A riving knife is adjustably mounted in alignment with the saw blade slot. A saw blade guard is pivotally mounted on the riving knife.

Abstract: A hand-held powered file has an arm assembly carrying a pulley around which passes an abrasive belt. The arm assembly is urged into a position tensioning the belt by a spring. A control knob has a cam track which cooperates with a follower to relieve the tension exerted on the belt by the spring by moving the assembly rearwardly against the spring.

Abstract: An air cooled bearing assembly for the armature shaft of an electric motor comprises a heat sink with an axial bore and spaced outwardly extending fins along its external surface. The fins are of a greater depth over part of their length and the junction between the parts of different fin depth is round to form a seating for a resilient mounting member. Located in the bore is a bearing sleeve which is an interference fit in the bore.

Abstract: A two-speed gear box for handheld electric drills and the like has the movable parts associated with gear changing on or associated with a lay shaft. Gear changing is preferably effected by moving a pair of dogs, slidably mounted in holes through a lay shaft gear, to drivingly engage in either of two dog clutch members on the lay shaft. A thin flexible arm, preferably including a ring around the lay shaft, mounted in cantilever fashion from a movable base effects movement of the dogs. Should the dogs not be in proper register with a respective dog clutch member when changing speed, then the arm flexes and urges the dogs into driving engagement when proper register occurs. A family of two-speed drills having different specialized functions, e.g. a drill, a hammer drill, a screwdriver/drill, a screwdriver, etc., can be produced with the maximum parts in common enabling greater manufacturing flexibility and lower cost of manufacturing the family.

Abstract: A laminated core of a stator of a universal motor consists of two core parts each of which bounds a portion of a central opening through the stator. The stator has at least one field winding, and at least one longitudinal part of this field winding, running in the direction of the longitudinal axis of the stator, is located through the central opening. The core parts are separated from one another at junction planes which run substantially parallel to the plane in which the two longitudinal parts of the field winding are located. The two core parts of the stator, the field winding or windings, and the armature are all assembled by relative movement along a single direction, thus facilitating automation of this assembly.