Abstract: A radial arm of a radial arm saw comprises a lightweight metal casting of inverted U cross-section and having opposing longitudinal grooves in the inner faces of the side walls of the inverted U. A metal strip of resilient arcuate cross-section is press fitted into each groove to form guides for supporting and guiding a power saw unit movable along the radial arm. The lighter weight of the radial arm is particularly advantageous for a portable radial arm saw, and the inserted metal strips form inexpensive durable guides.

Abstract: A multipurpose hand truck has a base frame with a handle frame connected thereto and orientatable to different angular positions relative to the base frame. A pair of wheels, which support the base frame, are mounted for movement in location along the base frame and are releasably securable thereto in at least two alternative spaced apart locations. Preferably wheel support brackets have channel sections therein which are slidable lengthwise along side members of the base frame. Pivotal plates connecting the handle and base frames enable the handle frame to be stored in overlying relation to and spaced above the base frame. A front load retaining plate is invertible to form a rest support.

Abstract: A portable machine tool, comprising a base structure, a work surface supported by the base structure for supporting, in use, a workpiece, and a column pivotally connected to the base structure and being pivotal between an upstanding operative position in which the column extends upwardly above the work surface and a lateral inoperative position. An operating unit is attached to the column and is supported thereby above the work surface in the operative upstanding position for operating, in use, on the workpiece. A locking arrangement releasably secures the column in the operative upstanding position. Preferably the column is pivoted behind and to the rear of the base structure, and a part of the work surface is removable to expose a space inside the base structure in which the operating unit is at least partially housed when the column is pivoted to the inoperative lateral position. In this way the machine tool, which is preferably a radial arm saw, is made more compact for transporting and/or storage.

Abstract: Disclosed is an overspeed protective apparatus for an electric motor having pairs of stator windings normally connected in parallel, the apparatus having an actuating mechanism responsive to an overspeed condition of the motor and an electrical switching assembly normally connecting the stator windings in parallel but adapted upon actuation by the actuating mechanism to interrupt the parallel connection and connect pairs of windings in series.

Abstract: Several embodiments of tachometers generators for use in controlling the speed of electrical motor driven tools. In each embodiment a toothed rotor (28, 52, 72, 92, 122) is fixed for rotation with the motor armature shaft (23, 53, 73, 93, 124) and a sensor (31, 55, 75, 96, 126) is juxtaposed to the rotor. The sensor is comprised of a core (32, 56, 76, 98, 127) having a first end portion (33, 57, 77, 99, 128) juxtaposed at a first location relative to the rotor and a second end portion (36, 58, 78, 101, 129) that is juxtaposed to the rotor at a second, spaced location. A permanent magnet (37, 59, 79, 102, 131) is interposed between the second end portion and the rotor with one of its poles aligned with a second end portion and the other of its poles aligned with the rotor.

Abstract: The invention is directed to a disconnect and overload bypass arrangement for a hand-held portable tool equipped with an electric motor supplied from a source of electrical energy and a manually operable on-off switch for switching the tool on and off. The arrangement includes a self-reclosing disconnect switch operatively connected to the motor to temporarily disconnect the same from the energy source in response to an overload condition; and, circuit control means for supplying energy to the motor at a reduced level when the disconnect switch is open whereby the motor will continue to operate at reduced torque pending self-reclosure of the disconnect switch and thereby provide the operator of the tool with an audible and visual indication that the motor has not been deactivated by manually actuating the on-off switch.

Abstract: The invention is directed to a cutterhead for a portable power planer. The cutterhead includes a cylindrical body having a substantially cylindrical surface and defining a rotational axis about which the cylindrical body rotates during normal operation of the power planer. A solid elongated cutting member is provided and has a channel formed therein to define at least two cutting edges. The cylindrical body has an elongated recess formed therein for holding the cutting member. The recess extends in a direction parallel to the rotational axis of the cutterhead and defines a longitudinal aperture in the surface for accommodating one of the cutting edges. The recess has a recess wall extending inwardly away from the aperture to surround and hold the cutting member against the centrifugal forces acting thereupon during the rotation of the cylindrical body.

Abstract: The invention is directed to an actuator mechanism for controlling the operation of the motor of a portable, motor-driven tool having a housing for enclosing the motor. The actuator mechanism includes a switch actuable between off and on positions for interrupting the flow of current to the motor and for supplying current to the motor, respectively. A slider is operatively connected to the switch and slideably mounted in the wall of the housing of the tool so as to be slideable between first and second positions corresponding to the off and on positions of the switch. A resilient member resiliently urges the slider into the off position of the switch.

Abstract: The invention is directed to a foldable, portable workbench having a work table and a support structure for supporting the work table. The support structure includes a pair of mutually spaced leg assemblies and each of these leg assemblies, in turn, includes a pair of legs pivotally connected at one end thereof to the work table. Articulated linkages pivotally interconnect, respectively, the two legs of each pair of legs to each other and at least one of the legs to the work table. The articulating linkages are connected so that the work table and leg structures are stacked in juxtaposition to each other when the workbench is in its folded position and, so that the other ends of the leg structures are spread apart from each other with the work table substantially transverse to the leg structures when the workbench is in the erected position.

Abstract: The invention is directed to an abrasive sheet for cutting a workpiece and is adapted for use with a sanding tool having a base plate with a plurality of apertures formed therein and equipped with a suction arrangement for establishing a partial vacuum at each of the apertures. The abrasive sheet includes a base sheet having a plurality of apertures formed therein and located thereon to register with the apertures of the base plate. An abrasive material is secured to the base sheet for defining a plurality of channels thereon which extend outwardly from each one of the apertures of the base sheet.

Abstract: A workpiece supporting and clamping arrangement includes supporting structure defining a supporting surface. A first top member having an upper surface is supported by the supporting structure on the supporting surface. A second top member likewise has an upper surface and both upper surfaces lie in a substantially horizontal plane. The top members also have respective mutually adjacent side walls defining clamping surfaces. A guiding structure is provided for guiding the second top member relative to the supporting structure. The second top member can be moved along the guiding structure so as to adjust the position of the second top member with respect to the first top member.

Abstract: The invention is directed to a chuck for grasping a tool such as a drill bit or the like and adapted to be tightened with the aid of a chuck key. The chuck includes a hollow body defining a longitudinal axis and having a front end for receiving the tool therein. A plurality of elongated jaws are movably mounted in the hollow body. A sleeve is rotatably mounted on the body and threadably engages the jaws to move the jaws in the body to clamp and release the tool whereby substantial radial forces are transmitted to the body by the jaws when the jaws are tightened on the tool. The sleeve extends in the direction of the longitudinal axis of the hollow body to surround the hollow body at the region of the jaws for supporting the body against the radial forces. A gear is provided for coacting with the chuck key to actuate the sleeve to move the jaws for tightening the jaws on the tool.

Abstract: The invention is directed to a foldable, portable workbench having a work table and a support structure for supporting the work table. The support structure includes a pair of mutually spaced leg assemblies and each of these leg assemblies, in turn, includes a pair of legs pivotally connected at one end thereof to the work table. Articulated linkages pivotally interconnect, respectively, the two legs of each pair of legs to each other and at least one of the legs to the work table. The articulating linkages are connected so that the work table and leg structures are stacked in juxtaposition to each other when the workbench is in its folded position and, so that the other ends of the leg structures are spread apart from each other with the work table substantially transverse to the leg structures when the workbench is in the erected position.

Abstract: A portable workbench has a supporting structure defining a supporting surface. The supporting structure includes a collapsible leg assembly for supporting the supporting surface above a floor surface. A first top member having an upper surface is supported by the supporting structure on the supporting surface. A second top member likewise has an upper surface and the upper surfaces lie in a substantially horizontal plane. The top members also have respective mutually adjacent side walls defining clamping surfaces. A guiding structure is provided for guiding the second top member relative to the supporting structure. The second top member can be moved along the guiding structure so as to adjust the position of the second top member with respect to the first top member.

Abstract: The invention is directed to a gear transmission for an angle tool such as a grinder, polisher, sander, angle screwdriver or the like having a drive motor for driving an output spindle shaft. The motor has a drive shaft defining a longitudinal axis transverse to the output spindle shaft. The gear transmission connects the drive shaft of the motor to the output spindle shaft and includes a first stop and a second stop on one of the shafts. A first gear is mounted on the one shaft so as to abut against the first stop and a second gear mounted on the other one of the shafts. A resilient annular bearing is tightly held between the second stop and the first gear; and, a cut-shaped retainer is disposed on the one shaft for containing the resilient annular bearing.