Abstract: A D.C. tool switch assembly is provided with a pair of field effect transistors (FETs) maintained internally of the housing. The switch assembly is configured of a number of subassemblies maintained within the housing, including a contact subassembly having the motor and battery contacts and a pair of pivoting contacts. The field effect transistors are maintained on a second subassembly which nests within the housing and is substantially orthogonal to the contact subassembly. A post passes through the pair of FETs and is formed to engage a heat sink on each of opposite sides of the switch housing. The heat sinks are separate and distinct from each other and individually formed. Each of the heat sinks makes close contacting engagement with an associated one of the FETs. The post provides for interconnection between the FETs and the pair of heat sinks.

Abstract: A switch actuating assembly having an attachable trigger accommodates the implementation of numerous trigger designs and configurations with a single switch assembly. The slide actuator has a head and neck portion which is adapted for locking and mating receipt by a pair of deflectable legs in U-shaped configuration positioned in spaced apart relationship from a pair of flanges. The head of the actuator is engaged in the space between the flanges and the legs, while lips on both the legs and the neck portion provide further interlocking engagement. The positioning of the head within a space between the flange and legs prevents axial movement of the actuator with respect to the trigger assembly, while the interengagement of the lips prevents any vertical movement between the two.

Abstract: A power switch is provided for control of the electric motor of a power hand tool, such switch including a shorting bar to achieve a dynamic brake on the motor after the termination of the application of power thereto. In one embodiment of the invention, the shorting bar is fixed within the switch housing and moving contacts upon the slide are brought into contact therewith after the slide has moved a sufficient distance to terminate the interconnection between the power source and the motor. In another embodiment, the shorting bar is maintained upon the slide and engages fixed contacts interconnected with the motor when the slide has moved a fixed distance beyond a point of disconnecting the power source from the motor.

Abstract: A reversible electric switch has movable contacts on opposite ends of a rotor adapted for interengagement with diametrically disposed pairs of stationary contacts. Intermittency or rocking of the movable contacts with respect to the stationary contacts is eliminated by extending drive pins from the rotor into the slot provided within the contact face of the movable contact, such pins passing only partially through the thickness of such contact face. Accordingly, the force applied to the movable contacts to achieve rotation thereof is substantially at the interface between the stationary and movable contacts, substantially eliminating any force couple or moment thus precluding any rocking of the movable contact upon the rotor or other relative movement between the two.

Abstract: A universal diac is provided for implementation in controlling an SCR in a motor speed control circuit. The diac is provided with dissimilar interconnections between the emitters and base, such that the device operates as a standard diac in one mode of operation, and as a zener diode in an opposite mode of operation. The zener characteristics are achieved by the implementation of a shorted base configuration.

Abstract: A low voltage DC one-shot circuit momentarily increases the voltage applied by a NiCad battery pack to the gate of a MOSFET. A charge pump generates a supply voltage to a monostable multivibrator which is manually actuated by a switch to emit an output pulse of fixed amplitude and pulse width. The pulse is passed through a level shift network where it is summed with a bias voltage for application to the gate of the MOSFET.

Abstract: An electrical adapter is provided for interconnection with a switch intended for interconnecting a line voltage with a motor. The adapter has four blades extending therefrom for receipt by plug-in receptacles for the switch. The adapter, through a printed circuit board, interconnects the blades with receptacles for receiving wires from a motor, from a filter, and from a line voltage. The line voltage connectors are of the screw-in type, allowing the adapter to convert a switch having plug-in connectors to one having screw-in connectors for the line voltage.

Abstract: A manually operated switch lever moves arm 105 along resistor 113 to generate a "raw" motor speed demand signal which is amplified and inverted by amplifiers 115 and 119 to form a "base line" demand signal.The "raw" demand signal and a motor load signal at the output of amplifier 154 are compared in amplifier 125 to generate an "error" signal. The "error" signal and the "base line" demand signal are summed in amplifier 129 to form a variable reference voltage which is applied to the non-inverting input of comparator 132. The second input to comparator 132 is a triangular shaped wave which is centered about V/2. When the amplitude of the oscillator output wave exceeds the reference voltage, the output of the comparator 132 is low and switch 160 is off. Thus, variations in the D.C. reference voltage at the output of amplifier 129 control the ON-off duty cycle of MOSFET switch 160 to adjust the power applied to motor 106.

Abstract: In accordance with the present invention, there is provided an electric reversing switch comprising an insulated base having an elongated cavity defined therein. An elongated insulation member is provided for oscillatory motion about an axis through the cavity through an angular interval between a first and second position. Conductive bridging elements are provided on the ends of the insulation member and biased outwardly from the insulation member along the axis thereof. A first pair comprising first and second fixed contacts is supported in the base, each including a contact portion within the cavity and being symmetrical disposed relative to the axis through the cavity.

Abstract: In accordance with the present invention, there is provided an electric reversing switch comprising an insulated base having an elongated cavity defined therein. An elongated insulation member is provided for oscillatory motion about an axis through the cavity through an angular interval between a first and second position. Conductive bridging elements are provided on the ends of the insulation member and biased outwardly from the insulation member along the axis thereof. A first pair comprising first and second fixed contacts is supported in the base, each including a contact portion within the cavity and being symmetrical disposed relative to the axis through the cavity.

Abstract: A trigger operated switch assembly for a portable hand tool such as an electric drill that includes a switch casing, housing a switch contact module and a reciprocally movable contact carrier operatively engageable with the switch contact module for controlling communication of electrical energy from a source to an electrical load. An elongated arm extends through an opening in the switch casing and operatively interconnects the movable switch contact module with trigger structure. A seal arrangement prevents or substantially inhibits the entry of foreign material into the switch casing and includes a seal located in wiping relation with the elongated arm and mounted within an opening integrally molded in the switch casing. An additional seal seals a gap between the switch contact module and an inside surface of the casing. An elastomeric cap covers an end opening of the casing and includes apertures through which electrical conductors extend and are connected with the switch contact module.

Abstract: An electrical switch actuated by a longitudinally reciprocable electrical contact carrier, with such reciprocation being brought about by a two-piece rocker actuator with one of the actuator pieces comprising a removable locking key which when removed from the actuator assembly prevents movement of the contact carrier and thus prevents actuation of the switch.

Abstract: An integral electrical switch adapter for mechanically and electrically connecting a battery to a switch module without wires or soldered connections. The adapter includes a generally planar base having a first pair of flexible upstanding spaced attachment arms at the sides of the base for detachably securing the adapter to an associated electrical switch speed control module. The base also has a second pair of flexible downwardly extending spaced electrically conducting attachment arms at the sides of the base for electrically and mechanically securing the adapter to leads on an associated battery in detachable relationship therewith. The base also has a pair of upstanding elongated electrical switch bayonnet-type prong connectors on the front of the base and electrically connected, respectively, to the second pair of attachment arms for detachable electrical connection to associated leads on the module, thereby mechanically and electrically connecting the battery to the module.

Abstract: An electric switch mechanism for portable electric motor drive type tools having a reciprocable contact carrier and a movable electrically conductive bridging contact carried by the contact carrier for making and breaking electrical contact with coacting stationary contacts in the switch mechanism. The bridging contact has a protuberance at each point of contact with the contact carrier to ensure that such contact therebetween at each such point is always at the same spot(s) on the bridging contact when the bridging contact is reciprocated by the contact carrier in either direction.

Abstract: A trigger operated tool handle electrical switch in which each conductor wire connected to the switch is releasably secured therein by a spring-like retainer blade biased diagonally against the wire. Each retainer blade has a release arm for deactivating the retainer blade thus permitting easy withdrawal of the conductor wire. The release arm has a laterally extending handle lug on its exteriorly exposed free end to provide a handle and also to provide for engagement with the switch housing to limit inward movement of the release arm. The inner end of the release arm is beveled to provide a plane-to-plane contact with the retainer blade for a positive contact therewith.Each conductor wire connected to the switch is releasably secured therein by a spring-like retainer blade biased diagonally against the wire. Each retainer blade has a release arm for deactivating the retainer blade thus permitting easy withdrawal of the conductor wire.

Abstract: An electrical switch having spaced stationary contacts and a contact carrier carrying a bridging contact in linear reciprocation relative to the stationary contacts, with the bridging contact biased toward the stationary contacts. The bridging contact has spaced opposite contacting ends forming a leading contact end and a trailing contact end for sliding movement between a bridging position where the contacting ends contact their respective stationary contacts, and a non-bridging position where the leading contact end is out of engagement with its stationary contact. The bridging contact is rotatably hinged to the contact carrier and a projection is disposed between the stationary contacts for engagement with the leading contact end for pivoting and lifting the leading contact end from its stationary contact in coaction with the hinged connection with a quick break action during movement of the contact carrier to the non-bridging position.

Abstract: A portable electric motor-driven tool including an electric motor and an electrical control system for controlling the speed of the motor. The control system includes an electric switch for controlling the flow of electrical current to the motor and a composite thyristor and heat sink assembly, with electrical current conducting wires connecting the switch with the assembly. The motor has a fan providing an air stream for cooling the motor. The motor housing has a cavity disposed in the airstream and is configured to receive the thyristor and heat sink assembly and its electrical current conducting wires in quickly detachable relation therein. The heat sink includes an elongated base having laterally extending heat dispersing vanes of various sizes with each vane having a wing portion extending laterally from the vane for added heat dispersement.

Abstract: An electrical switch having spaced stationary contacts and a contact carrier carrying a bridging contact in linear reciprocation relative to the stationary contacts, with the bridging contact biased toward the stationary contacts. The bridging contact has spaced opposite contacting ends forming a leading contact end and a trailing contact end for sliding movement between a bridging position where the contacting ends contact their respective stationary contacts, and a non-bridging position where the leading contact end is out of engagement with its stationary contact. The bridging contact is rotatably hinged to the contact carrier and a projection is disposed between the stationary contacts for engagement with the leading contact end for pivoting and lifting the leading contact end from its stationary contact in coaction with the hinged connection with a quick break action during movement of the contact carrier to the non-bridging position.

Abstract: This invention relates to an electrical switch actuated by a longitudinally reciprocatable contact carrier and such reciprocation being brought about by tilting of a rocker actuator by means of a push button effect.

Abstract: A manually operable releasing mechanism for plug in-type terminals that are used for rapidly connecting electrical conducting lines to an electrical unit, and providing for rapid deactuation of the retainer for the conducting line to permit ready withdrawal of the conductor line from the unit, when so desired.