Abstract: A magnetic base drilling machine includes a base having a magnet coil therein and a motor assembly mounted on the base for driving a rotary cutting tool. Electrical circuitry, including switches for applying power to the magnet coil, for reversing the direction of current to the magnet coil, and for controlling the current to the motor are provided for controlling the magnet coil and motor. A user-manipulatable control handle includes a multi-function control cam having cam surfaces that selectively control the switch that applies power to the magnet coil and which physically blocks operation of the motor switch until the magnet coil is energized. Conversely, the magnet coil cannot be de-energized until the motor switch is moved to its off position. If desired, the direction of the electrical current applied to the magnet coil can be reversed to assist in removing the base from a magnetized work surface.

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: A hammer-drill is adapted for drilling a hole in masonry and subsequently driving a threaded masonry fastener therein. The hammer-drill has a driving output shaft nested concentrically within a driving output sleeve. The shaft and sleeve both extend forwardly of the tool housing, and both are driven continuously by respective gearing in the tool. The sleeve, however, is driven at a substantially lower rpm than the shaft and at a higher torque. After the hole is drilled, a tubular member is releasably and drivingly coupled to the sleeve. The tubular member encloses the masonry drill bit, which is continually rotated, and the drill bit need not be removed from the tool to seat the fastener. The tubular member has a forward portion provided with a socket for the head of the masonry fastener.

Abstract: An improved rotor comb construction (and method of assembly) for a power lawn rake has a plurality of spring tines axially stacked along a tubular rotor shaft. Each of the tines has a retention coil portion and a working coil portion spaced therefrom. The retention coil portion frictionally engages the outer surface of the rotor shaft. The working coil portion has a radially-extending ground-engaging element. A radially-inturned end of the retention coil portion is received in a respective radial hole in the shaft, thereby keying the tines to the shaft for conjoint rotation. Each hole in the rotor shaft is displaced circumferentially from its adjacent hole, preferably by an angle .theta. which equals 360 degrees divided by the number of holes. With this construction, the holes and hence the spring tines are arranged in a substantially uniform helical formation about the axis of the rotor shaft.

Abstract: A method for producing an annular composite washer subassembly for use as a `soft` mount for the abrasive disc subassembly of a portable grinder includes first and second relatively movable mold portions with each mold portion having a pair of spring-biased pins therein. A first flat annular washer having a pair of holes is placed over the pins in the first mold portion and a second annular flat washer having a pair of holes is placed over the pins in the second mold portion. The pins of the first mold portion extend through the holes of the first washer to engage the second washer, and, conversely, the pins of the second mold portion extend through the holes of the second washer to engage the first washer. The first and second washers are positionally maintained in their respective mold portions by the pins of the opposite mold portion while a plasticized plastic material is injected into the mold and allowed to solidify between the so-positioned washers to form the composite washer assembly.

Abstract: An improved mounting means is provided for the driven pulley of a power lawn rake. The driven pulley has a through axial bore. The rotor shaft is received in the bore and extends therethrough. A central tubular hub is formed on the inner face of the driven pulley and has a pair of diametrically-opposed openings formed therein. A transverse pin is carried by the rotor shaft and has radially-projecting end portions received in the openings in the hub, thereby keying the driven pulley to the rotor shaft. A self-locking retaining ring is received over the extending portion of the rotor shaft and resiliently bears against the outer face of the driven pulley, thereby retaining the pulley on the rotor shaft.

Abstract: An annular composite washer assembly provides a "soft" mount for a tool element subassembly mounted on the threaded output spindle of a portable grinder or other power tool. The composite washer includes a pair of flat annular washers and a molded body therebetween. The body has integrally-molded inner and outer annular bands joined integrally with the inner and outer diameters of the respective washers. A first pair of blind axial pockets, diametrically opposed to one another, extends through the first washer and the body and terminates at the second washer. A second pair of blind axial pockets, diametrically opposed to one another and shifted circumferentially with respect to the first pair of blind axial pockets (preferably by ninety degrees) extends through the second washer, through the body, and terminates at the first washer.

Abstract: A waveform synthesizer for generating single or poly-phase waveforms of selected wave shape and frequency for driving AC machinery including, for example, single or poly-phase induction, synchronous or other type motors or the like, includes a plurality of controllable power-switching device pairs for selectively switching power from an oppositely poled DC source to the corresponding power utilizing circuits of the driven device. The swithching device pairs are controlled to provide switched pulses of selected widths, spacings, and repetition rates to generate the desired current waveform. The power switching device pairs are selectively switched by a control circuit that includes a microprocessor controlled memory that is divided into p addressable pages with each page including s sequentially accessible memory locations containing the switching device pairs control information necessary to synthesize the desired waveform.

Abstract: A pair of manually-manipulatable spring-loaded buttons are accessible outwardly of the side walls of a pair of respective vise brackets secured beneath the table of a portable foldable workbench. When the buttons are pressed laterally inwardly, respective latching mechanisms are released to enable the workbench to be raised from a lowered storage position into an erected working position, and vice-versa. The buttons facilitate a rapid movement of the workbench from one position to another, and the buttons are conveniently located on the workbench for improved ergonomics.

Abstract: A double-insulated portable electric tool has a housing with a pistol-grip switch handle portion and a switch cover portion removably secured to the switch handle portion forwardly thereof. An electric switch is mounted on the back of the cover and is provided with an actuating member. A trigger is mounted on the front of the cover and is coupled to the switch actuating member. The switch is accessible only upon removal of the switch cover from the switch handle; and even unauthorized removal of the trigger will not render the switch accessible. As a result, the switch may be replaced easily without an inadvertent interference with the double-insulating feature of the tool.

Abstract: A turbine-driven sander includes a relatively thin, one-piece resilient dust shroud having a skirt surrounding a sander housing. The skirt has a rear wall which is split to form two opposing end portions, which are releasibly connected at an integral joint. The skirt has a front wall including a nozzle cover portion, and a pair of side walls having inwardly-extending lips. When attached to the housing the skirt sealingly engages the housing and creates a passage for dust-entrained air to flow from a platen to the nozzle. The air then flows to the turbine, eventually being exhausted into a source of vacuum.

Abstract: A surgical cast cutter or other power tool comprises a main tool section and a complementary hose section releasably secured to the tool section rearwardly thereof. The sections have respective cooperating rib means formed therein which slidably engage each other (in a direction transverse to the longitudinal axis of the tool section) as the sections are brought together; and the sections are retained by a releasable latching means. A low-voltage electric motor in the tool section drives a transmission which oscillates a cutter mounted forwardly of the tool section. A debris conduit in the tool section communicates with an opening formed in the hose section when the sections are joined together. The hose section carries a flexible vacuum hose communicating with the opening therein, thereby facilitating removal of dust particles generated during operation of the cutter to remove a plaster cast.

Abstract: The front end plate for the motor of a portable pneumatic tool has an integral annular portion extending forwardly of a bearing seat in the end plate. An internal ring gear is formed within the annular extending portion and engages planetary gearing carried by an output spindle. The planetary gearing engages a pinion gear on the motor shaft, and the shaft is journaled in a bearing retained in the bearing seat in the end plate. The annular extending portion of the end plate has an outer cylindrical surface for piloting the counterbored rear portion of a housing within which the output spindle is journaled. The end plate is alined circumferentially with the motor housing, and independently thereof, the end plate is alined circumferentially with the cylindrical liner of the motor. As a result, the motor liner is automatically alined with the motor housing during the assembly of the tool.

Abstract: A radial saw including a table with a work support surface to which a frame is connected below the work support surface. A post is connected to the frame at the rear thereof, and a support arm cantilevers over the table from its post connection. A pair of support rods, one round and one square are affixed to the support arm. A slide is fitted with bearings that will separately journal the round rod in close fit and the square rod in loose fit. A motor for the saw is carried by the slide to be moved therewith in translatory motion across the work support surface. The frame and the post are each angularly adjustable to permit selective straight cutting, or various miter and compound angle cuts.

Abstract: A quick lock-release mechanism for a trigger of a trigger switch mounted in the handle of a drill housing for activating a motor of a drill, which mechanism will selectively lock and release the trigger. The trigger is slidably connected in the handle with a tapered member affixed in the handle. A locking member is slidably connected to the tapered member and is in superposition to the trigger. A spring is disposed between the trigger and the locking member normally to urge each in opposite directions. The locking member is moveable outwardly of the handle to be forced by the tapered member into a wedge lock position against the trigger whereby the trigger switch is locked "on" and releasable upon slight trigger depression.

Abstract: A slam-shut valve or overpressure shutoff device used in series with, and upstream of, a pressure regulator to provide overpressure protection for apparatus downstream of the pressure regulator in the event of regulator failure. Overpressure or failure of the regulator automatically triggers operation of the slam-shut valve to close the same and prevent further passage of the gas through the pipeline. The slam-shut valve is normally in the open position, and the invention provides for manually resetting the slam-shut valve to reset it in the open position once it has been triggered closed.The valve element is carried on a lever which is pivotally mounted on a reset shaft and spring-biased to close, but prevented from closing by the latch which releasably holds the lever in the open position.

Abstract: A dustless portable electric router comprising a base having a dust chamber formed below a motor mounted to the base to be axially adjustable therein. A pair of handles are connected to the base with a passage formed in one of the handles in communication with the dust chamber. A blower is formed on the top side of the motor with the router connected to and driven by an extension from the motor armature shaft. A flexible conduit interconnects the handle passage and the blower, and a dust bag collects the dust and debris from the blower discharge.The dust chamber has side openings which are enclosed by detachably connected plastic shrouds that provide operator visibility. A light is connected in the other handle and serves to illuminate the dust chamber and the surrounding work. The dust bag is hung from the blower at the "back" of the router housing, and the blower is positioned remote from the work engaging flat bottom of the router base.