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 portable circular saw includes a single, one-piece thermoplastic housing having an interface portion which interchangeably mounts either a pivot adjust or vertical adjust subassembly, whereby two types of saws may be constructed using the same field case. One type adjusts saw blade depth of cut by pivotal movement of the housing relative to a reference plane. The other type adjusts saw blade depth of cut by transverse movement of the housing relative to the reference plane. The pivot adjust subassembly includes a one-piece foamed plastic auxiliary handle having an integral handgrip portion, pivot and lower guard bumper. The vertical adjust subassembly includes a one-piece rectangular rail member having an outer perimeter edge surface which guides the movement of a vertical adjust bracket. The pivot handle and the one-piece rail member, respectively, are interchangeably and snugly mounted on a common locating surface formed in the field case interface portion.

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: An improved power lawn rake has a rotor provided with a plurality of ground-engaging spring tines. The dead leaves and other debris are carried by the rotor along the curved forward wall of a deflector box, and are discharged between the deflector box and a front channel and into a molded bin. The bin is removably mounted on respective side housings of the main frame of the power lawn rake. Ground-engaging forward wheels are vertically adjustable on brackets mounted on the front channel. The wheels are nested within externally-accessible recesses formed in the bin. A driving motor is cantilever mounted on one of the side housings of the frame for driving the rotor. The drive is through gearing (in a gear case secured to the motor housing) and through a belt and pulley arrangement accessible through a cover plate removably secured to the side housing.

Abstract: A cordless electric tool in which a motor is mounted in a housing and to which housing a battery source is connected to operate the motor. The battery source is in the form of a battery pack that will be slide-fitted into the housing to be detachably connected thereto. The tool housing has a hollow portion or cavity which receives the battery pack. The motor has a pair of terminals which extend into the cavity to mate with co-acting battery terminals of the battery pack. Resilient means, preferrably an "O"-ring yieldably engages the motor terminals to increase the mechanical and electrical contact between the respective motor and battery terminals.

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 power tool, such as a surgical drill, has a tool element retained in a collet coupled to the output spindle of the tool. Resilient member constantly maintains the collet in its closed position. Upon rotation of the spindle in a reverse direction, opposite to its normal driving direction, a cam is actuated to open the collet against the force of the resilient member, thereby facilitating removal of the tool element from the collet. Preferably, the tool is of the cordless type and has a reversible electric motor controlled by a pair of triggers mounted on the pistol-grip handle for the tool. The triggers are conveniently disposed adjacent to each other and are easily distinguishable from one another, thereby providing for a convenient one-hand operation 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: A turbine-driven sander includes a minimum of one-piece sealed housing members so interconnected as to form a nozzle, a turbine chamber, and a valve chamber. A plurality of elongated support members are integrally formed on a housing member. Fasteners are inserted in the elongated support members to clamp the housing members together. A flap valve mounted in the valve chamber opens the turbine chamber to a source of vacuum, thereby driving a turbine rotatably mounted in the turbine chamber. This rotation in turn vibrates a platen through a direct-drive system. The platen is supported upon one of the housing members by two platen support members. A noise attenuation system at the front end of the housing includes a two-passage nozzle which is curved to interrupt the line of sight from a turbine air inlet to the turbine. A side branch resonator communicates with the nozzle via noise-attenuating holes in a cover plate located above the nozzle.

Abstract: A turbine-driven sander includes a direct drive system in which a one-piece thermoplastic shaft is rotatably journalled in a housing and mounts a two-piece turbine at one end and a counterweight and bushing at the other end. A machine screw is inserted through a longitudinal clearance bore in the shaft and clamps the turbine halves, shaft, counterweight and bushing together. The bushing is in turn pressed into a ball bearing, which is mounted in a platen. When the turbine rotates, the platen is oscillated, balanced by the counterweight.

Abstract: A vise is cantilever mounted to a workbench, projects forwardly thereof, and is disposed below the extended plane of the workbench table top. The vise includes a pair of U-shaped brackets, secured to the underside of the table top, and a pair of tubular beams slidably received in the respective brackets. Each of the beams is selectively indexed to its cooperating bracket, thereby providing a "coarse" adjustment. A fixed rear vise jaw is disposed on top of the beams, transversely thereof; this rear vise jaw is secured to the brackets and abuts against the lower portion of the longitudinal front side of the table top. A movable front vise jaw is mounted on top of the beams, transversely thereof, and may be moved in a non-parallel relationship with respect to the fixed rear vise jaw for clamping tapered workpieces therebetween.

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.