Abstract: A drive unit for direct drive of an information-storage disk comprises a brushless dc external-rotor motor having a permanent-magnet rotor magnet arrangement of considerably reduced axial length. Electrostatic charge is removed from the rotor shaft by a metallic spring element which engages the shaft periphery from within the interior of the rotor housing. An electromagnetic braking arrangement is located interiorly of the housing. The packet of stator plates for the stator has an axial length shorter than that of the rotor magnet arrangement, but is provided at its axial end faces with skirted-rim flux-conducting elements whose peripheral skirt portions form useful-air-gap extensions in cooperation with the rotor magnet arrangement.

Abstract: Collectorless (brushless) three-phase DC motor having a permanent-magnet arrangement and a three-phase winding, these being movable relative to each other, and having three position sensors which are stationary relative to the winding and controlled by the permanent-magnet arrangement to supply sensor output signals. The winding's coils are energized by current in a cyclical sequence in dependence upon the sensor output signals, the latter being offset by 120.degree.-el. one from the next. Induced coil voltages are offset by 120.degree.-el.; the coil voltages, in crossing zero, are alternately positive for at most 180.degree.-el. and negative for at most 180.degree.-el. and their sum is equal to zero for all relative positions as between the magnet arrangement and the winding. The position sensors are so arranged relative to the winding's coils that the sensors' changes-of-state substantially coincide with the zero-crossovers of the associated induced coil voltages.

Abstract: The system includes vertical posts with apertured disks secured thereto at intervals, coupling heads, wedge-like keys, scaffold pipes, coupling head extensions, and tank-link heads. Each coupling head has a horizontal slot receiving an apertured disk when the head is pushed into mounted position thereon, and has top and bottom key-receiving openings above and below such slot. A wedge-like key extends down through the top key-receiving opening, through a disk aperture, then through the bottom key-receiving opening, fastening the coupling head to the disk. Coupling heads for horizontal scaffold pipes have extensions insertable into the pipes. Diagonal scaffold pipes have tang-link heads, whose tank has an aperture for a pivot provided on an associated coupling head. Conventionally, the disks, coupling heads and pipes are all made of steel, the disks of 9 mm thickness and 122 mm diameter. The disclosed lighter-weight version employs disks and scaffold pipes made not of steel, but of light metal such as aluminum.

Abstract: A chair is disclosed comprising in combination four legs, seat, backrest and a hidden central underframe that supports the seat. Each leg of the chair comprises two leg rods defining a central recess for receiving an arm projecting outwardly from the hidden central underframe.

Abstract: The apparatus travels along a multi-tier arrangement of poultry cages, each tier comprising two rows of cages, the cages in these two rows adjoining back-to-back. The apparatus has transversely spaced, depending side units travelling along the cage-fronts and each including a feed container and a lift conveyor lifting feed from the container up to levels associated with the different tiers. At each such level a respective outflow chute on each side unit receives feed, continuously, from the lift conveyor and discharges the same into a feed trough that extends horizontally along the cage-fronts at the respective long side of the multi-tier cage arrangement, so that during dispensing-apparatus travel each longitudinally successive portion of the feed trough receives feed directly from the travelling outflow chute's discharge end. Each chute has an internal feed-flow passage formed by an inclined bottom wall, down along which the feed slides, as well as side walls and a top wall.

Abstract: A double-headed body contact piece has first and second acoustic connector portions connected to first and second acoustic passages of a stethoscope-tube attachment, and further has a first, non-differential auscultation head with a single auscultation chamber and a second, differential-auscultation head with a pair of chambers which latter are to be placed simultaneously with each other against a patient's body with a predetermined spacing between them. A switchover mechanism has first and second settings, involving registration and non-registration of various passages internal to the body contact piece. In the first setting, acoustic connections are established leading from the single chamber of the first head to both the first and the second acoustic connector portions, these two connections being of at least equivalent geometry and having the same dimensions so as to be acoustically equivalent to each other.

Abstract: Designed especially for hand-held dictation devices the motor has a three-phase external stator and two-pole permanent-magnet internal rotor, the two enclosed by an external housing from one axial end of which the rotor shaft projects out, its other axial end provided with a thrust bearing for the rotor shaft's other end. At least one Hall element, although more typically three, is provided, located at the peripheral edge of one of the axial ends of the rotor to sense axially emanating stray rotor flux. The rotor is directly secured to the rotor shaft, the shaft being ferromagnetic and near its outwardly projecting end provided with a ferromagnetic bearing mounted in a ferromagnetic end plate, so that stray flux sensed by the Hall element can travel from the rotor to the Hall element along a magnetic circuit for such sensed stray flux, but with the magnetic circuit being made up of motor components and structural parts that are required anyway.

Abstract: In a two-conductor, two-pulse brushless d.c. motor (10) driver transistors (44, 45) are provided for the end-stage transistors (52, 53) and are connected at a control electrode thereof to a potential (point 47) which, e.g., amounts to half the supplied d.c. voltage. These driver transistors are activated by a Hall-IC (32) having a digital signal (41). In order to avoid an abrupt switchover from one conductor (25) to the other conductor (26), each driver transistor (44, 45) has its own RC-stage (43', 46' or 43", 46"). In this way one produces currentless gaps between successive stator-current pulses and implements a relatively soft switching of the end-stage transistors, so that the motor is caused to run quietly.

Abstract: A one-phase motor has two conductors energized alternately via respective pnp and npn transistors and from the same output of a Hall-IC, without polarity inversion. When the Hall signal goes high the first transistor goes conductive and the second non-conductive, or vice versa. Capacitive delay elements slow down the switching-ON and -OFF of the two transistors. The capacitive delay elements have the undesired effect that, in response to the self-same change in the value of the Hall signal, the signal at the base of the OFF transistor changes comparatively quickly to switch the same ON, whereas the signal at the base of the ON transistor changes comparatively slowly to switch the latter off, which can lead to both being briefly conductive simultaneously, leading to voltage spikes and precluding safe dissipation of inductive energy in the transistors themselves.

Abstract: In the case of a two-pulse brushless d.c. motor narrow auxiliary poles (81-84; 115-122) are provided in the region of the boundaries (44, 45) between neighboring main poles of the rotor, the auxiliary poles being at least in part of polarity opposite to that of the surrounding main poles of the rotor. As a result of this, one obtains an especially favorable functional dependence of the induced voltage upon rotor angular position.

Abstract: A hand-held dispenser and applicator apparatus dispenses adhesive labels, stickers, or other such adhesive elements that are adhesive on at least one of the faces thereof, from a supply of such adhesive elements adhesively carried on a carrier tape, and furthermore designed to apply such adhesive elements to documents, cartons, album pages, or to other such workpieces. The apparatus comprises a guide structure defining a guide path for guiding adhesive-element-bearing carrier tape to a dispensing location and from there for guiding away the carrier tape freed of dispensed adhesive elements.

Abstract: A small motor having a planar air gap has a rotor comprising a rotor shaft journalled in a carrier pipe of small diameter at whose outer periphery are mounted shape-retaining rotor coils which are cantilevered out into the air gap. This provides a rotor of very small axial moment of inertia, affording very short start-up times. The printed circuit collector has lamella-group connectors on both sides of the substrate. Such a motor is suitable especially for signal-recording or -reproducing apparatus. The arrangement of the rotor coils is symmetrical and yields a very simple and compact motor construction.

Abstract: A drive unit for direct drive of an information-storage disk comprises a collectorless D.C. external-rotor motor having a permanent-magnet rotor magnet arrangement of considerably reduced axial length. Electrostatic charge is removed from the rotor shaft by a metallic spring element which engages the shaft periphery from within the interior of the rotor housing. An electromagnetic braking arrangement is located interiorly of the housing. The packet of stator plates for the stator has an axial length shorter than that of the rotor magnet arrangement, but is provided at its axial end faces with skirted-rim flux-conducting elements whose peripheral skirt portions form useful-air-gap extensions in cooperation with the rotor magnet arrangement.

Abstract: When the motor's permanent-magnet rotor is in a first range of angular positions a stator-winding phase is energized to have a first magnetic polarity, and to have an opposite second polarity when the rotor is in a second range of angular positions. The rotor angular position is sensed by a magnetic-field-sensitive semiconductor element, especially a Hall generator, responsive to the field from the permanent-magnet rotor. When the rotor is in a range of angular positions between such first and second ranges, all power transistors are rendered non-conductive, by control signals derived from the magnetic-field-sensitive semiconductor element by intermediate circuitry, to render the stator-winding phase currentless during the time interval within which commutation is to occur.

Abstract: Drive arrangement comprising a collectorless d.c. motor and a rpm-regulating arrangement. The motor comprises a permanent-magnet rotor and a stator winding arrangement. The latter is connected to a current source in dependence upon angular-position signals by means of an electrical commutation arrangement. The rpm-regulating arrangement produces a regulator signal that is a function of the deviation of the rotor's actual rpm from a desired rpm. There is provided an arrangement for modulating the regulator signal in synchronism with the rotation of the rotor. As a result of the action of the modulation arrangement, the current flowing in the stator winding arrangement between each two successive commutation operations initially builds up beginning at a point in time at least approximately coinciding with the point in time at which the commutation occurs, and the drops off again until a point in time at least approximately coinciding with the point in time at which the next-following commutation occurs.

Abstract: A motor for direct or coaxial drive of a disc storage, mounted in a center hole formed in a storage disc includes a rotor and a stator which form together with an air gap separating the rotor from the stator a magnetic circuit. The stator has a single-phase winding. The motor produces an auxiliary reluctance moment complementing the electromagnetic torque produced by the winding and being offset in time relative to the electromagnetic torque. Due to the positioning of the motor within the center hole of the disc a very compact construction is obtained.

Abstract: A timing signal has a value changing during its period and a frequency dependent on actual motor rpm. A reference signal has an average value indicating desired rpm and a superimposed sawtooth component used, after desired rpm is reached, to generate phase-error information. A comparator receives the two signals and produces an output pulse which begins when the timing signal reaches the value of the reference signal, and which ends at the end of the period of the timing signal. In the case of rpm error, the comparator output pulse duration serves to regulate rpm; in the steady state, it serves to regulate phase. A sample-and-hold capacitor converts the aforementioned pulse duration into a lengthier motor-control signal. In the case of rpm error, the pulse duration inaccurately indicates the amount of rpm error, the inaccuracy corresponding to the difference between the average and instantaneous values of the reference signal.

Abstract: A brushless DC motor, most especially a linear motor, has a wound and an unwound part, one part forming the stator and the other the armature, and includes a permanent field magnet arrangement to generate flux and windings linked by the flux. One motor part is provided with a series of flux-conducting portions and the other part is provided with a plurality of flux-carrying portions forming an air gap with the flux-conducting portions. By making the distance from one flux-conducting portion to the next small, and the distance from one flux-carrying portion to the next small, it becomes possible to minimize the distance through which the armature need move to go from a position linking maximum first-polarity flux with a respective winding to a position linking maximum second-polarity flux with that winding.

Abstract: An improved motor assembly including a brushless D.C. motor and an annular member defining a platform for the drive electronics and speed control circuits of the motor. The member is carried on a fixed support within the outer envelope of the motor and includes a thin disk-like body providing a pair of opposed surfaces for mounting the components of the circuits. The fixed support of the motor has a flat annular face surrounding the drive shaft of the motor, and the annular member engages and is secured to the flat face of the support in surrounding relationship to the shaft. In a preferred embodiment, the housing of the motor defines part of the rotor of the motor and is for rotation with the shaft. A flange is secured to the support near the opposite end of the shaft for mounting the motor on a fixed support, such as on the base of a housing forming a part of a disk drive unit.