Abstract: The invention provides a motor drive unit for use in conjunction with an atherectomy device which limits the torque exerted on a drive cable for rotating a cutting blade in the device. In a preferred embodiment, a motor drive unit includes a motor having a shaft coupled to the drive cable for rotating the cutting blade, a power supply coupled to the motor and a switch for selectively connecting the power supply to the motor. A torque control circuit connected to the power supply and the motor controls the torque exerted by the motor when the switch is closed, whereby the current to the motor is continuously increased from zero to a start-up level, the start-up level being the minimum current sufficient to turn the cutting blade.

Abstract: A battery-powered tool (10) generally comprises a motor (24) having a positive terminal (64) and a negative terminal (66) extending therefrom for continuous engagement to a rotatable actuator (26). Actuator (26) has a plurality of conductive arms (28) extending therefrom for contact with a battery assembly (20) such that the actuator (26) can be selectively rotated to engage the motor (24) in both high speed and low speed operations.

Abstract: For the purposes of assembling an electric tool, and especially an electric hand tool such as, for example, a hand drill, a grinder or a sabre saw, it is proposed to use modular components that are to be axially inserted into and connected with each other. The components comprise a self-contained electric driving motor that supports the rotor shaft in a centered position by means of end shields on both sides that are rigidly fixed to the stator, a self-contained gearing head that is fixed to the motor, and at least a partially tubular, single piece main housing that accommodates the driving motor and the gearing head, an electric circuitry module inserted into the main housing, and a rear cover for the housing.

Abstract: A spindle motor for high speed hand tools includes a rotor and a sleeve that is journaled about the rotor. A pressure generating mechanism creates sufficient air pressure in a clearance between the rotor and the sleeve to form a pressurized air film in the clearance when the spindle motor is in normal operation. A plurality of armature coils and a plurality of magnetic sensors for detecting magnetism of magnetic poles in the rotor are provided on the outer surface of the sleeve. The rotor has a field magnet with multiple magnetic poles. The sleeve is formed of a ceramic material whose dielectric constant is 10 or lower. The pressurized air film created by the pressure generating mechanism is sufficient to radially support the rotor so that the rotor does not significantly contact the sleeve during normal operation of the spindle motor.

Abstract: The powered hand tool for machining includes an enclosed drive motor having a rotor shaft and is provided with at least one interior air duct through which drawn-in cooling air passes to cool the drive motor. To prevent the drive motor from being clogged or damaged by magnetizable dust, which is produced from the machining process among other things, a permanent magnet is nonrotatably attached to the rotor shaft and also located in the air duct or ducts. The invention also resides in an air-cooled drive motor having a cooling-air flow with a permanent magnet located in the vicinity of the cooling-air flow and fixed nonrotatably to the motor shaft.

Abstract: A dc permanent magnet motor for a surgical handpiece, comprises a housing and a stator including windings fixed in the housing. A rotor is supported for rotation in the housing and has a forward extending rotatable shaft. A conventional sensor adjacent the windings and rotor has stiff conductive electrodes extending rearward. A printed circuit board disk has plural axial holes along the perimeter thereof defining conductive sockets into which the electrodes plug, which disk is located coaxially rearward of said rotor and windings and is fixed with respect to the housing. A rear-facing, separable connector holder behind the printed circuit board has terminals rear-facing therefrom for connection to an external electrical supply. The holder is fixed with respect to the housing. Electrical connections are effected between the conductive sockets of the printed circuit board and the rear-facing terminals of the holder.

Abstract: A battery-driven handtool is configured with a holder (4) for housing the current source, this housing being detachably connected to the handgrip (1) of the tool. The holder is journalled for asymmetric rotation (around A) on the free end of the handgrip, so as to enable the outer dimensions of the tool to be minimized, by causing the holder to take at least two mutually opposing positions when the working space is confined, thereby also enabling the center of gravity point (TP) of the tool to be changed.

Abstract: A domestic vibration apparatus, in particular a dry-shaver or hair trimmer, in which rotary movements of a two-pole permanent magnet (9) forming a rotor are converted into vibratory movements of a vibration tool by means of a lever system (13) which preloads the drive in such a way that the rotor (9) can oscillate about a rest position,t he two-pole permanent-magnet rotor (9) without pole-pieces being arranged in the U-shaped stator of a single-phase synchronous motor.

Abstract: A power tool apparatus which is hand-holdable during operation serves for facilitating especially heavy duty work, e.g. on a high scaffolding. The apparatus is composed of three building blocks, a central one haivng an elongated enveloping shell and an integral transverse wall dividing the shell into a forward and a rearward compartment. The latter contains a speed-reducing transmission unit and has a motor unit attached to the shell rear end. As a third building block the operator equipped with a kit according to the invention has the choice of several inset units, among them a simple front end wall with an intermediate shaft, and the same end wall and an impact-generating unit on the intermediate shaft, which inset units he can introduce through the open front end of the enveloping shell and exchange them as required without taking apart the transmission unit or detaching the motor unit. A handle can likewise be attached to the central shell unit.

Abstract: An electric motor suitable for use in a steam sterilizable surgical tool comprising a casing with a peripheral wall, plural magnets, an armature and structure rotatably supporting them in the casing, structure locating the magnets axially and circumferentially in the casing, and a sleeve radially outwardly pressing against the magnets. Wedged rings can supply part or all of the outward pressure on the sleeve.

Abstract: An electrically driven vibrating apparatus such as a dry shaver comprises a single-phase synchronous motor having a drive shaft, together with a part to be reciprocated. A cam is rotated by the motor drive shaft, and a lever is journalled about a pivot and is in contact with the part to be reciprocated. A pressure roller is mounted on the lever and is in constant contact with the cam profile. A compression spring acts on the lever to urge the pressure roller towards the cam.

Abstract: A hand-held, motor-driven erasing machine which operates directly from the nominal wall outlet voltage and comprises a generally tubular housing having a front portion and a rear portion which are releasably attached together. A chuck tube is mounted for rotational movement within the generally tubular housing. A DC permanent magnet motor is operatively disposed within the generally tubular housing and includes a wire-wound armature surrounding and attached to the chuck tube, a commutator whose brush surface is positioned at a right angle with respect to the rotational axis of the DC motor, a permanent magnet assembly operatively surrounding the wire-wound armature. A rectifier device is operatively connected to receive the AC voltage from the wall outlet and provide a DC output to the DC motor. A switch assembly is operatively connected between the output of the rectifier device and the DC motor.

Abstract: A drive mechanism for a domestic vibration-type apparatus is provided, in which the rotor shaft (19) of a single-phase synchronous motor drives a cam-and-follower mechanism which converts the rotary motion of the rotor into a vibratory motion, the rotor and the stator having a main field direction (22) and (16), respectively. The longitudinal axis of the mirror-symmetrical cam extends at an angle to the main field direction (22) of the rotor. Rollers (31, 31a) which follow the cam (21) are arranged on a pivotal arm which is pivot about its central portion and a vibratory part (39) to be driven is arranged on the driving end (35) of this pivotal arm. As they cooperate with the cam the rollers are constantly in contact with the cam profile.

Abstract: A small domestic appliance is driven by means of a single-phase synchronous motor (2) whose drive shaft (5) drives a load (9), the work function being independent of the direction of rotation of the motor and the operating noise and vibrations produced by the motor being dependent on the direction of rotation of the motor. In the transmisson system a unidirectional blocking device (41) forces the rotor to start in the optimum direction of rotation. In particular, the single-phase synchronous motor (2) including its transmission path to the load (9) is constructed that the optimum operating noise is obtained in that direction of rotation in which the torque exerted on the rotor (3) by the stator current becomes zero before the magnetic detent torque has become zero, when the stator coils (4d) are not energized. This has led to a stable rest position.

Abstract: A brushless D.C. motor, suitable for use as a hand-held surgical tool, includes a field of self-supporting coils arranged between a pair of impregnated fiberglass epoxy sheets situated in an air gap formed by a rotatable shaft having an even-number plurality of magnets formed thereon, and a non-electrically conductive housing. The individual magnets abut one another upon the shaft to prevent a magnetic return path from the substantially unidirectional field produced thereby, and are formed in relationship to the coils such that a single rotor pole will never be under a single coil, in order to minimize induced shorted currents.

Abstract: A protection against overheating not only of the heat transmitting component (2), but also of the components (3) surrounding said component is achieved. A latent heat store (1) is provided between the heat transmitting component (2) or a part thereof and a component (3) to be protected from overheating or a part thereof. The latent heat store (1) comprises a latent heat storing agent, whose melting-point T is between the operating temperature of the heat transmitting component (2) and the maximum permissible temperature of the component (3) to be protected. The quantity is proportioned so that the storage capacity of the latent heat store (1) is sufficient for the amount of heat maximally to be transmitted by the heat transmitting component (2). Between the heat transmitting component (2) and the latent heat source (1) and between the latent heat store (1) and the component (3) to be protected a thermal insulation (4,5) is provided.

Abstract: The electrically driven hand tool such as hand-operated drilling, milling or sawing machine includes a universal driving electromotor controlled via electric circuits by means of a plurality of switches, the control elements of which are in the form of pushbuttons arranged in a matrix or rectangular array on the top surface of the tool housing. The pushbuttons are illuminated when actuated and include a digital keyboard connected to a microprocessor to enter digital data corresponding to the desired value of speed or torque, and the microprocessor adjusts, via a power circuit, the electromotor to the entered data.

Abstract: A hygienic device comprising an a.c. oscillating motor which has a fixed oscillation rate dependent on the a.c. supply frequency. The amplitude of the oscillations or torque of the motor is varied by varying the power supplied to the motor. The amplitude or torque may be varied in discrete steps by switching different resistors in series with the motor. Reed switches are used to switch the resistors and are mounted obliquely, to facilitate assembly and to reduce the danger of electric shocks to the user.

Abstract: A switch limit apparatus for a multiple position switch having an actuator accessible through an opening in a casing in which the switch is disposed. The switch actuator is provided with several parallel ridges spaced such that only one ridge is accessible through the opening for each switch position.

Abstract: A hand held device with built-in motor for rotational drive of small tools. The hand held device includes an outer housing consisting of a larger diameter rear part which contains an electric driving motor, an intermediate part of small diameter which contains motion transmitting means, and a front part in which is mounted a holder for the tool to be driven. The electric driving motor is a brushless motor having a rotor encapsulated in a sealed insulating enclosure and includes permanent magnets covered with a layer of conducting metal and a stator made up of multi-phase winding coils embedded in a molded plastic material. The motion transmission means consists of non-contacting magnetic coupling means.

Abstract: A motor drive for a window lifter in motor vehicle doors has an integrated flat housing containing a permanent magnet DC motor and a worm gear driven by a worm on the extended motor shaft; the housing has two halves which are separable in the plane of the motor axis and which serve as the return yoke of the motor.A single permanent magnet is arranged in the space defined on two sides essentially by the motor rotor on the one hand and the worm gear on the other hand and each of the two housing halves serves as a pole plate.

Abstract: A counterbalanced rotor is mounted on a rearward extension of the armature shaft of a portable electric tool. The rotor is nested within the annular portion of a ring member which is piloted on the rearward bridge portion of the motor field case. An end cap is secured to the field case and engages the annular portion of the ring, thereby retaining the ring against the bridge on the field case. The annular portion of the ring has an external boss with a notch formed therein substantially tangential to the annular portion. A printed circuit board is received in the notch and carries a semiconductor sensing device, such as a Hall-Effect generator, for cooperation with a magnet carried by the rotor. A spider member is retained in the bridge and has a bearing nested therein for journaling the commutator end of the armature shaft. The spider has a number of openings formed therein.

Abstract: For adjusting the rpm with the assistance of mechanical regulators consisting of low-retentivity magnetic material, the air gap between the rotor and the stator, and/or the magnetic return between the stator field poles of opposite polarity, and/or a magnetic shunt is adjusted. The illustrative embodiments are particularly provided for d.c. subfractional horsepower motors for the drive of dental tools.

Abstract: A drive section for a dental handpiece having a housing with means for connection to a supply hose and means for connection to a grip section of the handpiece, the housing receiving a drive motor having a stator surrounding a rotor and at least one coolant line section extending therethrough in a direction parallel to the axis of the drive section, characterized by the stator consisting of a hard metallic material with at least one section of soft metallic material, each section being a portion of the circumference of the stator and extending the length thereof, and each section having a means for receiving a portion of the coolant line. Preferably, the stator has a cylindrical configuration in which the sections form a segment of the cylindrical configuration and are provided with a longitudinally extending bore which forms a portion of the coolant line.

Abstract: An external-rotor type drum motor in which the rotor includes axially extending members to which are fastened the respective end bells of the motor. The motor is further provided with a drum cylinder which surrounds the rotor and the end bells and is secured axially by means of a ring which is bolted to one of the end bells and rests against an inner shoulder formed on the drum cylinder.

Abstract: Disclosed herein is a hair clipper comprising an outer housing of electrically insulating material, a motor located in the housing and including a field structure, an armature structure including a shaft, and bearing assemblies spaced axially of the armature structure and engaging the armature structure and the field structure for supporting the armature structure for rotation relative to the field structure, each of said bearing assemblies including a bearing and a bearing sleeve fabricated of electrically insulating material and located to isolate the bearing from one of the armature structure and the field structure, and screws mounting the field structure from the outer housing.

Abstract: A portable electrical appliance such as an electric dry shaver wherein all the operative elements are mounted on a shroud support assembly for removal as an operative unit from the shaver casing. The support means further include a structural arrangement for permitting the vibratory motor of the appliance to be suspended clear of the casing sidewalls to allow for slight pivotal movement thereof during operation to absorb and reduce vibrations in operation of the appliance.