Abstract: An arrangement for the determination of the temperature of a direct-current motor. The temperature is determined in an indirect manner from the temperature-dependent armature resistance, with the armature resistance being determined as the quotient of the voltage being applied to and measured at the motor terminals and of the blocking current of the armature, and being set in relation to the respective temperature. The current signal determined from the current flowing within the armature is averaged with adjustable, calculated integration times with the aid of an integrator that can be controlled by a microcontroller. The arrangement, can be used for the indirect determination of the rpm rate (N) and/or variations that are critical or of interest in the rpm rate of the motor. The rpm rate is proportional to the voltage (U.sub.ind) induced within the armature, taking into consideration a motor-typical proportionality constant (.kappa.) according to equation N=.kappa. U.sub.

Abstract: An air switch assembly for an electric motor including a first snap action switch, a second snap action switch, and an actuator, is described. The first snap action switch is connected to the motor start winding and the second snap action switch is connected to the run winding. An actuator is positioned within the air switch assembly such that the air switch energizes the start winding, energizes the run winding, and de-energizes the start winding while maintaining the run winding energized when the actuator is actuated from an initial position to a final position.

Abstract: In an appliance having an a.c. series motor, which comprises a rotor coil configuration and two stator coils, switching means are provided for switching the a.c. series motor to different speeds or speed characteristics. Both coil ends of each of the two stator coils are accessible from outside of the a.c. series motor and are connected to the switching means. The switching means connects either one stator coil or both stator coils in series or both stator coils in parallel and in series with the rotor coil configuration.

Abstract: The invention relates to a motor which comprises a drive system which has a stator (10) and a rotor (14), and a control system which controls the drive system and has circuit boards (21), (22), both being housed in a casing (2), wherein the casing (2) has a first conductive pin (25) for flowing a current to input power to the control system and a second conductive pin (26) for flowing a current to output from the control system to respective phases of a coil, and the circuit boards are supported by the first and second conductive pins. And, the invention relates to a method of manufacturing a motor which comprises the steps of using a first die (101) and a second die (102) which are mutually connected with a die split face (104) therebetween and a third die (103) which is inserted in the middle of the first and second dies, inserting and fixing a motor stator, a metallic cylinder and embedding members into a cavity formed by the first, second and third dies, and pouring a molten resin to effect resin molding.

Abstract: A device (1) for switching electromagnetic equipment. It is especially intended for switching a direct-current brake for a three-phase motor (3) with a switching contact (6) with a rectifier (7) with integrated protective circuitry downstream of the switching contact. There is current transformer (5) upstream of the switching contact. The transformer's primary winding is part of a conductor in the line that provides a voltage.

Abstract: Provided is a plug for changing an operating condition of an electric motor. The plug includes at least one electrical contact. A support structure includes at least one electrical contact. The plug is electrically connectable to the support structure in at least first and second positions in which at least one plug electrical contact engages at least one support structure electrical contact. The plug and the support structure engage each other independently of the electrical connection between the electrical contacts. The independent engagement means ensures that the plug may only be positioned in a predetermined number of suitable positions and may not be positioned in an unacceptable position which the plug would be positionable absent the independent engagement means. Indicating means are provided to further ensure that the proper electrical connection is made depending on the desired operating condition of the electric motor.

Abstract: A surgical power tool is disclosed including a power console and a handheld motor unit. The power console provides controlled power and to the handheld motor unit. Pressure sensitive switching elements on the handheld unit provide signals to the power console which are transformed into operating power to the motor unit including variable speed, speed range, forward/reverse, and safety. The handheld motor unit includes a chuck or tool receptacle and a Hall effect or other radiation field detector which response to the presence of a magnet or other radiation device as a part of the surgical tool, to identify the tool installed and provide a control signal to the motor, e.g., speed range limitation. The handheld motor unit housing is sealed and autoclavable.

Abstract: Systems and apparatus for integrating an air switch and a power cord into an electric motor, and methods for assembling an electric motor including an integral air switch and an integral power cord, are described. In one embodiment, an air switch and a power cord are incorporated into an electric motor. No additional removable cover is required for the switch and cord. To eliminate the motor centrifugal switch, an air switch is provided to control energization and de-energization of the motor windings. The air switch includes a snap action switch to cut-out the start winding used for ensuring that the rotor has sufficient starting torque.

Abstract: An integral brushless DC motor and drive package is disclosed that includes the brushless DC motor and drive circuitry supported by one of the motor end caps. The drive circuitry includes power electronic devices for converting input power to pulsed power for the motor. The power switching components extend from a circuit board and are received within recesses of the end cap. The switching components are electrically insulated from the end cap, but are thermally conductive to the end cap within the recesses to dissipate heat during operation. The switching components are preferably disposed in radially equally spaced positions on the circuit board to provide even heat loading to the end cap.

Abstract: A module and method are disclosed for adding an electrical device such as a timer to an existing electric motor such as that found in a whirlpool bath system for driving a water pump. The module includes an input connector configured for mating with a connector on a power cable, an output connector configured for mating with a power connector on the electric motor, and a timer electrically connected between the input and output connectors. The method of adding an electrical device to an existing electric motor using the module comprises the steps of removing the power cable connector from the motor power connector, connecting the module output connector to the motor power connector, and connecting the power cable connector to the module input connector. In this manner, an electrical device which is prewired between the module connectors can be coupled to an existing electric motor without the use of tools, without the aid of an electrician, and without any risk of serious electrical shock.

Abstract: Systems and apparatus for integrating an air switch and a power cord into an electric motor, and methods for assembling an electric motor including an integral air switch and an integral power cord, are described. In one embodiment, an air switch and a power cord are incorporated into an electric motor. No additional removable cover is required for the switch and cord. To eliminate the motor centrifugal switch, an air switch is provided to control energization and de-energization of the motor windings. The air switch includes a snap action switch to cut-out the start winding used for ensuring that the rotor has sufficient starting torque.

Abstract: An apparatus for adjusting carbon brushes of a reversible electric motor includes: a swivelable support; a fixed position contact plate disposed adjacent the support; a plurality of fixed contacts received in the contact plate and adapted to be electrically connected to field windings of the electric motor; and a plurality of brush holders arranged on the support for holding the carbon brushes, each of the brush holders having a facing surface which faces the contact plate. Each of the brush holders further includes a projecting portion projecting approximately perpendicularly from the facing surface in the axial direction into a region of the fixed contacts, projecting portions of the brush holders thereby forming switching contacts for making direct contact with the fixed contacts such that the fixed contacts are adapted to be in alternate contact with the carbon brushes for reversing a direction of rotation of the electric motor when the support is swiveled.

Abstract: A single-phase switched reluctance motor is disclosed. The motor includes a stator having a plurality of projecting poles and a rotor rotatably disposed adjacent to the stator. The stator and rotor poles may be formed from laminations of ferromagnetic material. Energizing coils are wound around one or more of the stator poles. When the coils are energized, the rotor develops torque. In one embodiment, the motor includes a motor starting mechanism which sets the rotor into motion before the stator coils are energized so that the rotor is never static in a preferred position. In another embodiment, the motor includes a rotor positioning mechanism which positions the rotor in a preferred starting position before the stator coils are energized.

Abstract: A switch lever for use with a centrifugal starting switch of an electric motor. The starting switch has at least one switch contact which is moveable, in response to axial movement of a centrifugal actuator, between a start position in which a starting winding of the motor is energized and a run position in which the starting winding is de-energized. The switch lever of the present invention operatively connects the switch contact with the centrifugal actuator for movement in response thereto. The switch lever has a cam follower at one end which is engageable with an annular actuator collar of the centrifugal actuator. The cam follower includes a contoured rear cam face which prevents the cam follower from becoming "stuck" behind a flat rear surface of the actuator collar during assembly or operation of the motor.

Abstract: A synchronous motor/generator is modified by mounting the conventional rotor on a sleeve that rotates freely on the main shaft rather than being fixedly mounted on the shaft. Limits to this rotation are incorporated in the design such that the maximum angular rotation of the rotor on the shaft equals half the stator advance that occurs during a complete full cycle of the AC stator winding voltage. In addition to smoothing transients, this configuration permits the machine to smoothly drop into the correct stator/rotor flux phase when it changes from a motor to a generator, and back into the correct phase for a motor, when the AC power is interrupted, and subsequently resumes, resulting in dropping a single cycle.

Abstract: A universal motor (18) for a power tool (10) has a stator assembly (22) and an armature (24). The stator assembly includes a plurality of interconnected field windings (28-34) to which current is supplied to run the motor. The armature has a commutator (36) including brushes (40a, 40b) for circulating current through the armature. To quickly and safely brake the motor, without excessively damaging the brushes, a switch (16) is interposed between an AC power source for the motor and the armature. In one embodiment, the switch shorts the armature during braking. In this embodiment, the switch includes sets (56, 58, 60) of electrical contacts by which the inner field windings (28, 30) are connected in series with the outer filed windings (32, 34); and the field windings are series connected with the armature.

Abstract: In a non-commutating-pole commutator motor, in particular as the drive of a power hand tool, a device for reversing the direction of rotation includes a switch (8) for reversing the direction of current in the rotor winding, and a brush apparatus (4) mounted immovably in the motor casing. The rotation of the plane defined by the commutating coils is chosen in such a manner that good commutation is assured in one of the two directions of rotation at full motor output. Furthermore, the switch (8) for reversing the direction of rotation yields the preferred direction of rotation in a first switch position and the opposite direction in a second switch position. In the switch position for the preferred direction, a smaller number of turns of the field winding (1, 2) in the electric circuit of the motor is effectively provided while, in the opposite direction of rotation of the motor, a larger number of turns is effectively provided.

Abstract: A switch assembly (10) for installation on a dynamoelectric machine (M). An electrical overload switch (12) is interconnected with the dynamoelectric machine and electrical conduits (C) are routed thereto for resetting the dynamoelectric machine after it is shut down due to an overload condition. A conduit box (14) has opposed sidewalls (16, 18) and endwalls (20, 22), and an open top and bottom. A bracket (30) on which the switch is mounted is sized to fit in the box for a switch element (32) of the switch to be positioned adjacent an opening (34) in one wall of the box. Dimples (44a, 44b) are formed in the wall against which the bracket is installed. The dimples extend inwardly into the interior of the box and act as stops for the bracket for properly positioning the bracket and switch within the box. A plurality of knockouts (K1-K6) are formed in the sidewalls for providing an opening through which electrical conduits are routed to the switch when a knockout is removed.

Abstract: A dynamoelectric machine of the present invention includes a stator, a rotor journaled with respect to the stator, and a rotor shaft having a longitudinal axis extending axially from said rotor. An auxiliary winding and a starting switch operable to de-energize said auxiliary winding upon the motor obtaining a predetermined speed is provided. A centrifugal actuator is mounted on the rotor shaft to actuate the starter switch to de-energize the starter windings when the rotor obtains a predetermined speed. The rotor shaft has a single wide groove formed thereon and the actuator has a sleeve which is journaled on the rotor shaft. The sleeve has an inwardly directed projection sized and shaped to fit in the shaft groove. The sleeve projection and shaft groove interact such that the actuator sleeve cannot be moved relative to the shaft and the switch without a great deal of force.

Abstract: A double pole single throw electric switch has normally closed contacts of one pole connected in a dynamic braking circuit with a motor load and normally open contacts connecting the motor to a source of power. A partial movable contact conductively connected to movable contacts of the normally open contacts is disposed in normally open position relative to one contact of the normally closed contacts to provide a parallel path through the switch for making and breaking the circuit to the power source.

Abstract: A motor comprises an armature, first and second commutators disposed at either side of the armature, first and second amateur coils wound on the armature through commutator pieces in a double winding back alpha type, and first and second stator coil groups respectively connected through brushes to first and second commutators. A first circuit formed of the first stator coil group, the first commutator, and the first armature coil is connected to a second circuit formed of the second armature coil, the second commutator, and the second stator coil group, in series or in parallel corresponding to a high voltage or a low voltage applied to the motor, thereby the motor shows the same output power without relation to the voltage applied thereto.

Abstract: A device for change-over switching of electric motors has a housing and two safety disconnecting switch systems positioned adjacently to one another in the housing. A cover is slidably connected to the housing so as to cover one of the safety disconnecting switch systems respectively. A fuse holder with fuses is detachably connected to the housing. Each one of the safety disconnecting switch systems has receiving elements for receiving the fuses. The safety disconnecting switch systems are electrically connected to one another such that upon insertion of the fuses into the receiving elements of one of safety disconnecting switch systems the electric motors rotate in one rotational direction and that upon insertion of the fuses into the receiving elements of the other one of the safety disconnecting switch systems the electric motors rotate in the other rotational direction.

Abstract: This apparatus incorporates an electric motor disconnecting safety switch within the motor's electrical terminal housing. This results in a single, compact device directly mounted to the electric motor body which is used for the safety disconnect as well as the termination point for the incoming power leads and the motor wire taps. The apparatus may be employed as a disconnecting device for single phase and three phase alternating current motors as well as various configurations of direct current motors. The apparatus further includes a simple and economical adapter plate mounting configuration which accommodates the device to a multiplicity of motor frames. This apparatus is used in three embodiments: the first being a rotary tumbler switching device with an external rotary hand operator; the second device being a draw-out disconnecting means; the third device including an integral motor starter which provides both disconnecting and motor controlling functions.

Abstract: A spinning- or twisting-machine has an elongated spindle bank, a row of rotatable spindles supported on the bank, respective individual drive motors on the bank for each spindle, respective electrical control circuits connected to the respective motors and electrically energizable to power the respective motor, and a plurality of electricity-supply conductors extending along the bank past the spindles. A respective housing support part for each spindle carries the respective electrical control circuit and is provided with electrical-input contacts. A mount engaged between the housing part and the spindle bank allows movement of the housing part on the bank between a closed position in which it surrounds and protects the respective circuit and in which the contacts conductively engage the supply conductors and an open position in which it exposes the respective circuit and disengages the contacts from the supply conductors.

Abstract: An industrial electric fan motor has a remote hand set in which both a switch and a motor capacitor are disposed. The remote hand set is connected to a casing of the fan motor by a control cord with a selectively engageable plug. The switch and the capacitor are serviced by disconnecting the hand set from the motor by unplugging it and plugging in a replacement remote hand set.

Abstract: A terminal board assembly for a dynamoelectric machine, adapted for supporting an overload device, comprises a body and an overload device support integral with the body and extending therefrom for cradling the overload device when the overload device is supported on the terminal board assembly. The body and the overload device support each include apparatus releasably secured in engagement with the overload device for retaining the overload device against displacement from the overload device support.

Abstract: A switch is used to disable electrical generation by causing a short circuit in a rotating main generator field of a brushless, synchronous generator to protect against transients voltage spikes during start-up. The switch is located inside of a hollow rotor shaft of the generator. In one embodiment the switch is activated by a solenoid assembly. In a second embodiment, the switch is activated by a alternate or redundant method by oil flow through the rotor shaft.

Abstract: An electrically driven handmixer comprises a manually actuated electric switching device for an electromotor with several switch steps (I, II, III) for permanent operation of the electromotor as well as at least one switch step (IL) for short-time operation. A coupling device is used for holding and driving various insertable tools, and an interlock ensures that after the insertion of the blending attachment or other knife-like tool into the coupling device, the electromotor remains separated from the power supply despite the activation of the switch steps (I, II, III) for permanent operation of the electromotor, whereas the electromotor remains connected with the power supply during the manual actuation of the switch step (IL) for short-time operation of the electromotor.

Abstract: An electric motor comprises bracket shaped end plates having extensions that lead directly to the stator and are connected to the stator by introducing the extensions into grooves. The motor includes a layered arrangement of components on the collector-side, comprising a carrier plate with a punched grid pattern forming the electric wiring. The grid pattern, together with the carrier plate, carry brush holders. Next in the axial direction is a switching ring bridging preselected line connections of the grid pattern by means of short circuiting bridges, and which is rotatably seated in a central recess of a mounting plate provided on the end plate. All connections can be fabricated by simple pressing and plugging and the motor is suited for fully automatic assembly operations.

Abstract: A contact structure for toy motors in which a battery case housing a battery and a motor case housing a motor are detachably and relatively rotatably joined by means of the outer circumferential surface of the end of the battery case and the inner circumferential surface of the end of the motor case, and terminals are provided in the vicinity of the ends of both cases in such a manner that the terminals can be brought into contact with, or separated from each other, characterized in that the cross-sectional shape of the ends of motor terminals provided on the motor case is formed into a U shape having a closed end on the side of the outer circumferential surface thereof, with the end thereof on the side of the axial line of the motor being opened, and the inside surfaces of the battery terminals are brought into contact with the outer circumferential surfaces of the closed ends of the motor terminals.

Abstract: A hand held vibrating instrument in the shape of a conventional pen or pencil writing instrument. The tip of this instrument is to be connected to a tool such as a thin brush. The instrument has a deflectable sleeve mounted within the housing wall of the instrument. Manual inward deflecting of the sleeve will cause operation of a motor which will rotate an eccentric weight and cause rapid vibration of the brush.

Abstract: In the case of a universal electric motor for any kind of drive, with a stator package, a rotatably mounted rotor with commutator, as well as end shields on both sides that also constitute the bearings for the rotor and a switching ring that can be rotated through predetermined angular amounts and carries the (carbon) brushes, it is proposed to insert into the end shield A a closely fitting anchor block that serves for locking together the two end shields with the intervening stator package; further, the switching ring can be mounted on an external annular end face of the end shield B that also carries the switching strips or switching rails needed for switching between clockwise and counter clockwise rotation, complete with contact areas situated in the plane of the annular end face and suitable for axial contacting, the said contact areas making contact with other axial contact areas on the switching ring to establish connections with the carbon brushes.

Abstract: A motor for a pump, especially a pump for a drum, barrel, or other tanks or containers. The motor has a housing in which a rotor is surrounded by a stator. The motor is an electronically commutated direct current motor that has no brushes. The switch or control device of the motor is an electronic switch or control device that is accommodated in the housing.

Abstract: In a 2 pole universal motor for a circular saw a secondary winding provides dynamic braking. Both run and brake windings are split electrically with respect to the armature. All windings are double-ended and wiring and winding is arranged so that all windings may be terminated directly to fixed termination points, four at each end of the stator, providing for axially oriented plug-in connection of brushes at the commutator end and switch and line at the fan end. There are no jumpers within the stator.

Abstract: A switching mechanism energizes a motor in response to selective actuation of switches in order to rotate an output shaft of the motor by an angle dependent upon the particular switch which is actuated. A base body connected to an output shaft of the motor carries slide terminals that slide on conductor paths of a stationary circuit board when the motor is energized. The conductor paths are connected to respective ones of the switches so that the motor is energized in response to the contact of a slide terminal with the conductor path associated with an actuated switch, and is de-energized when that slide terminal reaches an end edge portion of that conductor path. The end edge portions of the conductor paths are arranged substantially on the same circumference relative to the axis of rotation of the output shaft.

Abstract: Electromotors used as submersible motors consist of a fluid-tight housing (2), a shaft (3) mounted therein, the connecting end of which is brought out on one side in a leakproof fashion from the housing (2), a rotor (8) seated on the shaft (3), and a stator (9) fixed relative to the housing (2). In order for the electromotor to be switched over without appreciable expense from one voltage to another voltage in a very simple and reliable way, even by unskilled persons, a voltage selector switch (23) is provided in the interior of the housing (2). To actuate the voltage selector switch (23), there is provided in the region of the voltage selector switch a detachable housing part which, in the detached state, clears a housing opening through which the actuating element of the voltage selector switch (23) is accessible.

Abstract: A dynamoelectric machine in the form of an electric motor which can be easily converted between normal motor operation and remote actuation through a simple conversion device. The conversion device includes a remotely located on/off actuator for operating a switch attached to the motor. The switch is mounted to the motor through a simple bracket arrangement, and jumper wires are used to permit the switch element is be interposed in the electrical circuit of the motor without special tools by regular field personnel.

Abstract: A housing for a pressure washer for internal components of the washer such as a pump, an electric motor for the pump and a valve assembly. The housing has first and second identical interconnected housing halves. The inner surface of the housing halves include pairs of ribs interacting to engage the internal components.

Abstract: A pressure washer according to the preferred teachings of the present invention is disclosed including a pump driven by a gear reduced, high speed, series universal motor supported in a housing by a switch housing. The motor is stopped and started by a pressure actuation switch to remove the necessity of an unloader valve. A valve assembly is provided which includes provisions for allowing or for preventing weepage through the pump and for relieving excessive pressure. The housing is formed of identical, non-mirror image housing halves which are interconnected end for end. Pairs of ribs upstand from the inner surface of the housing halves, with the first of the pair of ribs of the first housing half interacting with the second of the pair of ribs of the second housing half to engage the internal components while the second of the pair of the first housing half and the first of the pair of the second housing half not interfering with the internal components.

Abstract: The present invention provides a modular fan construction in which the fan motor, with its operating controls, can be tested away from the fan housing and then fit into the housing without disassembly after the testing.

Abstract: A switch for controlling electric D.C., especially for a power tool held by hand during operation, for heavy duty work, preferably from an automobile battery, of 8 to 40 volts and sufficient amperage for at least about 180 watt-input into the idling tool motor, comprises a base mountable on the motor rearwall, fixed contactors on the base, a supporting member bearing shiftable contactor elements, a first engaging member on the base, another engaging member on the supporting member and pivotably engaged by the first engaging member, a resilient organ urging the two engaging members into engagement, and preferably enhancing contact pressure between the fixed and shiftable contactors when a manual actuator has pivoted the supporting member from neutral into an activating position. A restoring spring can return the supporting member automatically to neutral.

Abstract: An apparatus for testing a synchronizing control circuit for any assembly relying upon detecting the relative closeness of one voltage of varying frequency to another voltage of different varying frequency, comprising a test circuit including a first circuit for determining the frequency at which the control circuit operates and a second circuit for determining the operational response of an individual control circuit assembly. A test selection circuit is used to select the desired portion of the test circuit. The apparatus simulates the frequency difference for a frequency comparator circuit of multi generator installations and the operation of a starting synchronous motor, which enables all the components of the comparator control circuit and the components of the synchronous motor exciter control circuit to be checked without actual operation of the prime movers that generate the voltage of varying frequency.

Abstract: A modular tool assembly includes a single motor unit and a plurality of toolheads. The housings for the various toolheads include different engaging structures for engaging combinations of control switches of the motor unit, thereby providing different operating characteristics to the various tools formed by engagement of the motor unit and the toolheads. A direction reversing switch of the motor unit is placed in a fixed position by some of the toolheads and is left in a controllable condition by others. An on/off switch is provided in the motor unit, as is an on/off and speed control switch. The various toolheads include engaging means for engaging one or the other of the control switches, thus providing fixed speed or variable speed, fixed direction or reversible direction, for operation of a plurality of tools utilizing a single motor unit.

Abstract: The brush assembly for electrical motors comprises a housing cap (10) which consists of an insulating material and which closes the motor on its frontal end, the said cap's inner side (16) being provided with projections (7, 8) extending in parallel to the motor axis. These projections (7, 8) are penetrated by openings (12, 13) for the accommodation and fixation of elastic commutator brushes (1, 2). The contact lugs (32, 33) which can be inserted from the outside into the slot-shaped openings (12, 13) are coupled stationarily to the commutator brushes (1, 2) by virtue of a close-fit arrangement (36, 37) designed at the latter.

Abstract: A hand machine tool for clockwise and counterclockwise rotation includes a universal electric motor and a reversing switch. The reversing switch is comprised of a contact plate and a contact holder both provided with coupling elements for coupling the contact plate and the contact holder for limited relative rotation. The coupling elements of the contact plate and the contact holder enclose a dust-sealed chamber in which contacts are accommodated.

Abstract: This disclosure relates to an electric motor control designed for attachment to a support wall or to a pressure switch. The control comprises a support having a base portion and a mounting portion. The base portion has a plurality of electrical terminals attached thereto and has at least one lead opening formed therein for electrical leads. The mounting portion has a lead opening formed therein. A motor control switch including a plurality of electrical terminals is connected to the terminals of said base portion. The mounting portion includes first means for attaching the support to a pressure switch and second means for attaching the mounting portion to a support wall. A cover is removably attached to the base portion, and the control switch is mounted in the cover.

Abstract: A sub-assembly for an electric motor, including a reversing switch comprising a brush bearing plate having a circuit pattern imbedded therein with portions of the pattern exposed as pads on one surface of the plate, an opposed cover defining, together with the plate; a chamber including the exposed pads; an actuator movable within the chamber; a plurality of bridging contacts arranged for selectively coupling pairs of the exposed pads; and springs for biasing the bridging contacts into engagement with the exposed pads. As the actuator is moved within the chamber, actuator cam portions are interposed between various bridging contacts and pads so as to provide three distinct switch positions, namely, FORWARD, NEUTRAL and REVERSE. The brush bearing plate is generally U-shaped and has opposed brushes that are inwardly biased so that the entire switch sub-assembly may be fitted partially over the comutator of the motor, thereby bringing the brushes into an operative position.

Abstract: A portable electric tool has a switching device for reversing the direction of the current through the motor to reverse the motor. The switching device comprises two pairs of contacts which extend in cantilever fashion from a circuit board, a rotatable shaft having axially spaced apart terminals thereon, and the terminals being electrically insulated from the contacts by insulating collars secured to the shaft. Each collar has a window therein for access to the respective terminal, the contacts being resiliently biased against the collars with one of each pair of contacts engaging a respective terminal through the respective window in one direction of rotation of the motor and the other of each pair of contacts engaging the opposite respective terminal through the respective window in the opposite direction of rotation of the motor. A shoulder on the shaft may have flats to prevent rotation of the shaft while the trigger of a trigger-switch is actuated.

Abstract: A modulator motor and drive unit for use in an electrical device, such as a hand food mixer, wherein the motor is characterized by a low-cost speed control which is capable of providing a large number of discrete motor speeds. The speed control, rather than utilizing a multi-contact switch connected to the field coil by individual taps, has approximately twenty field coil continuous loop taps wound over a bobbin spindle in side-by-side relationship with a wiper contact being slideably movable relative thereto along a path from which the insulation has been removed. Positions of the wiper contact may be determined by replaceable detent elements provided with different detent patterns providing different series of motor speeds whereby the same motor and drive module may be provided within a suitable housing(s) for the economical production of several different models of such electrical devices having differing speed selections.

Abstract: A portable electric drill has a printed circuit board assembly mounted in a motor compartment and attached to a stator lamination stack. A motor reversing switch is mounted on the printed circuit board assembly and has an operating pin which cooperates with an actuating lever that is mechanically interrelated to a trigger switch for energizing the drill. The trigger switch remains inoperative until the actuating lever is positioned to allow the motor to be energized to drivingly rotate in either one or other rotational direction. The printed circuit board assembly also has mounted thereon brush holders, noise-suppression elements, brush terminals, and field coil terminals. A pivoted lever for operating the reversing switch pin may be disposed inside or outside the motor compartment.