Abstract: Two pairs of contact strips are mounted on the respective bridge members of an integral web portion of the molded field case of a power tool or other motor-driven device. The forward ends of the contact strips are cantilever mounted and automatically engage the respective terminals on the field, as the field is inserted into the field case and is secured therein. An annular wire harness is mounted on the rear bearing boss of the field case. Spaced contacts are carried by the wire harness and engage the respective ends of the first pair of contact strips. The respective ends of the second pair of contact strips are connected to terminals on the ends of the brush shunts. In a reversing embodiment, a third pair of contact strips is mounted on the bridge, and a rotatable reversing subassembly is mounted on the rear bearing boss in lieu of the wire harness.

Abstract: A carbon brush assembly comprises a brush box having a slit along one side thereof, and a carbon brush slidably mounted in the brush box with a spring connected between the brush box and the brush to resiliently urge the brush outwardly. An electrically conductive pin is inserted in a transverse bore in the brush and extends through the slit for movement therealong. A brush lead is electrically connected to the pin and a stop associated with the slit adjacent the outer end thereof. The stop forms a closed end of the slit for limiting movement of the pin therealong under the influence of the spring, and so retaining the pin in the slot when said brush wears out. Preferably, the brush is formed with breaking incisions in its sides adjacent the pin to enable the protruding end of the brush to break off and interrupt electrical connection with a commutator when the brush has worn to the end of its useful life.

Abstract: A container of paint or other liquid is seated within a pressurized vessel. Both the vessel and the paint container are designed with a special orientation. This assures that only the specially-designed paint container will be received within the pressurized vessel, and discourages the use of a standard commercially-available can of paint. The top of the paint container is closed by a diaphragm. The diaphragm has an annular recess normally closed by a removable plug. When the plug is removed, a delivery pipe sealingly carried by the vessel lid extends through the diaphragm and is received vertically within the paint container. A small opening in the diaphragm assures that the pressure internally and externally of the paint container will be substantially equalized. The delivery pipe is connected to a flexible feed tube, and the end of the feed tube is connected to a hand-held applicator. The applicator carries an on/off switch for interrupting the flow of paint to the applicator.

Abstract: An orbital-action reciprocating power saw includes a motor-driven transmission that causes a saw blade carrier to reciprocate along an axis of reciprocation and move in a direction transverse to the axis of reciprocation to provide an aggressive cutting action. The transmission includes a rotary-to-reciprocation drive mechanism defined by a rotatably driven gear having an eccentrically mounted pin that engages a slotted yoke connected to the saw blade carrier. The saw blade carrier is mounted in a `floating` bearing that accommodates both reciprocation and movement in a direction transverse to the reciprocation axis. A rocker arm is pivotally mounted intermediate its ends with one end engaging the floating bearing mount and the other end engageable with an axial-face cam portion of the rotatably driven gear. The rocker arm is effective to move the saw blade carrier in a direction transverse to the axis of reciprocation to provide the desired orbital action.

Abstract: A hot air gun having a hot air outlet is provided with a guard plate having a substantially straight edge transverse to the general direction of the hot air flow. This straight edge is downstream of the hot air outlet and defines the downstream extremity of the guard plate, the latter defining the boundary on one side of the hot air flow from the outlet. Preferably the guard plate has a flared flat part and a tubular part, the latter being detachably and rotatably mounted around the outlet. The guard plate is advantageously used when stripping paint adjacent a glass pane to minimize heating of the glass.

Abstract: An electric tool, especially a hand tool, is provided with a torque monitor. For this purpose the support bearings taking up the reaction torque of the electric motor in the housing of the tool are equipped with pressure sensors in the form of conductive plastic material, the electric resistance of which changes as a function of the pressure exerted.

Abstract: A drill press having a safety device for reducing the power to the motor when a drill bit becomes stuck, and a switch for temporarily overriding the safety device, when the latter is triggered by the drill bit becoming stuck, to temporarily increase the power to the motor for freeing the stuck drill bit. The switch has an actuating member, preferably a push-button, located at the end of the control lever whereby the operator can actuate the switch without letting go of the control lever. The front of the drill press preferably has a control panel with input and operating keys.

Abstract: A miter saw having a saw table which carries the saw unit and is rotatably mounted in a base plate is provided with means for locking the saw table. Such locking means comprise at least one through bore in the fence extending over the upper surface of the saw table and a bolt having a circular cross-section and being rotatably fitted in the through bore. Both the through bore and the bolt comprise an annular shoulder continuously increasing its distance from the saw table. The annular shoulders are in engagement and by rotating the bolt its end surface can be pressed onto the saw table.

Abstract: With a solenoid actuated tacker the setting of the penetration depth of the fastening elements is effected by adjusting the operating stroke of the armature with respect to the solenoid coil actuating the armature. To accomplish this there is preferably provided an armature stop displaceable in the direction of movement of the armature. The stop is preferably supported and moved by a cam-like element adjustably rotatable about an axis at right angles to the movement of the armature. In this way the drive-in depth of the fastening elements can simply and readily be adjusted.

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: Two pairs of contact strips are mounted on the respective bridge members of an integral web portion of the molded field case of a power tool or other motor-driven device. The forward ends of the contact strips are cantilever-mounted and automatically engage the respective terminals on the field, as the field is inserted into the field case and is secured in it. An annular wire harness is mounted on the rear bearing boss of the field case. Spaced contacts are carried by the wire harness and engage the respective ends of the first pair of contact strips. The respective ends of the second pair of contact strips are connected to terminals on the ends of the brush shunts. In a reversing embodiment, a third pair of contact strips is mounted on the bridge, and a rotatable reversing subassembly is mounted on the rear bearing boss in lieu of the wire harness.

Abstract: A reversible electric motor has two pairs of brushes, a separate pair for each direction of rotation. The mean diametrical positions of the two pairs are fixed with respect to the motor's stator and angularly offset. The brushes of the one or the other pair, exclusively, are selected for application against the commutator as a function of the selected direction of rotation. Preferably a rotatable cam is arranged to lift the brushes of the non-selected pair from the commutator and insulating segments are inserted between the lifted brushes and the commutator. To simplify wiring, adjacent brushes, one from each pair, may be electrically connected together. Both pairs of brushes may advantageously be lifted from the commutator during motor reversal to eliminate risk of short-circuiting the commutator and also to interrupt supply of power thereto.

Abstract: A jig saw has a pivotally mounted reciprocating saw blade assembly which is reciprocated by a drive shaft. A pendular stroke device generates an additional feed movement of the saw blade. The pendular stroke device comprises a rod like element reciprocating in a direction substantially parallel to the direction of reciprocation of the saw blade, a rotatable drive element driven by the drive shaft, and a pivotally mounted engagement element against which the saw blade assembly is spring biased. The rod like element is coupled to the rotatable drive element and acts to pivot the engagement element to pivot the saw blade assembly. The pivotal axis of the engagement element is displaceable to change the spacing between the engagement element and the rod like element to determine the degree of or eliminate pivoting of the saw blade assembly. Preferably, the engagement element is pivotally mounted on an eccentric formed on a shaft which has a handle for adjustably rotating the shaft.

Abstract: A power tool has a changeover mechanism for varying at least one operational mode of the power tool. A rotatable control member having a lateral periphery is connected to the changeover mechanism. A detachable cover plate, forming part of the housing of the power tool, has an aperture therein through which the control member protrudes, and the lateral periphery of the control member is covered by the cover plate. A latching arrangement comprises a first latch component formed in said lateral periphery, and a second latch component located on the underside of the cover plate, the first and second latch components cooperating to retain the control member in a selected position, and one of these latch components is resilient. Preferably the second latch component is resilient and may be formed integrally with the cover plate. The cover plate may have two apertures for two control members with a common resilient latch member on the cover plate for both control members.

Abstract: An electronic clutch for a multispeed electric tool includes a voltage sensor having a D.C. voltage output proportional to the current absorbed by the tool's motor and dependent on the motor operating temperature. A comparator compares this D.C. voltage with a suitably generated reference voltage, and if the former exceeds the latter it blocks the oscillation of an oscillator which via a power circuit controls a triac provided in the motor power supply circuit. Blocking the oscillator causes the deactivation of the triac, and thus stops the motor. The proportionality constant of the D.C. voltage, or that of the reference voltage, can be varied as a function of the tool operating speed. For this purpose, the voltage sensor or, respectively, the reference voltage generator includes a voltage divider in which resistors are provided which can be cut in or out by means of electric contacts controlled by the tool's speed change mechanism.

Abstract: An electric motor adapted to be assembled automatically with the minimum of manual handling has a brush box sub-assembly having a brush box with two opposed side walls and containing a brush. The two opposed side walls are stressed to grip and hold the brush against movement, the brush being released for movement in the brush box by separating sufficiently the opposed side walls upon insertion in the electric motor. Preferably, the brush box has a slot between the opposed side walls and a member in the motor is forced into the slot to separate the side walls. In assembling the motor, its stator is located on an end cap, the rotor inserted into the stator, and then the distance measured between an end face of the stator and a location on the shaft of the rotor, subsequently a shaft bearing in that end cap is pressed inwards an amount related to the measured distance to determine the end float of the shaft.

Abstract: A hand-held power tool, for example a rotary percussive drill, includes a component for undergoing linear movement and a bearing support for the component. The bearing support comprises a cylinder formed from sheet metal strip with the longitudinal edges spaced to form a gap in the wall of the cylinder. By making the bearing support from a sheet metal strip and providing a gap in the cylinder wall considerable cost savings are achieved.

Abstract: A switch has a body mounted directly on the rear bearing boss of the integral web portion of a molded plastic field case for a power tool or other motor-driven device. The switch has a pair of spaced contacts engaging the respective rearward end portions of a complementary pair of contact elements carried by the web portion of the field case. The respective forward end portions of the contact elements are connected to respective terminals on the field.