Abstract: A tape loop sensing arm is mounted for rotation with a plate (31) which extends into a core (37) and carries shaped lossy strips (34) for altering the quality factor of a coil (36) carried by the core.

Abstract: A tape drive control apparatus controls to set a tape speed to be constant in a fast forward or rewind mode (wherein a magnetic tape is driven by only reel motors without using a capstan) by using an output from rotation detectors for respectively detecting rotational frequencies of the supply and take-up reels, and to set a tape tension to be constant in a constant-speed mode (wherein the magnetic tape is driven by the capstan) by utilizing part of a tape velocity control system irrespective of the rotational frequency of the capstan.

Abstract: A web transport device for transporting a web wound on a rotary member to another rotary member, provided with a first calculating unit for calculating the ratio of rotating speeds of the unwinding and winding rotary members at a regular interval, a second calculating unit for calculating the ratio of rotating speeds of the unwinding and winding rotary members at the end of web transport on the basis of the value calculated by the first calculating unit at the start of web transport, and a unit for controlling the rotation of the rotary members through the comparison of the values calculated by the first and second calculating units, respectively.

Abstract: Use of a programmable source of stepping pulses to control the speed of linear movement of a material from a supply spool to a takeup spool wherein feedback signals provide an indication of the angular velocity of the supply spool and a function table provides information on the rate of stepping pulses to be applied to the takeup spool.

Abstract: The speeds of two capstans of a dual capstan type tape recorder are individually controlled by respectively associated first and second phase locked loops. Each phase locked loop includes a speed detector for generating pulses at a frequency corresponding to the rotational speed of the associated capstan, a phase detector receptive of the pulses and a motor for driving the associated capstan in response to the output of the phase detector. A reference frequency oscillator supplies a constant frequency signal to a first frequency divider and to a second, programmable frequency divider which are respectively associated with the first and second phase locked loops. The first and second frequency dividers feed their outputs to the phase detectors of the first and second phase locked loops, respectively, to allow phase comparison with the received pulse to control the associated motors.

Abstract: Apparatus for controlling the speed of advancement of tape extending between supply and take-up reels in a VTR during changes in the speed of advancement of the tape includes for each reel a tape radius detector which detects the radius of the tape on the respective reel from the center of the reel hub to the outer loop of tape; acceleration detector which detects the acceleration or deceleration of the tape during such changes in speed; a tape tension detector which detects the tension of the tape adjacent the respective reel; a torque detector which detects the torque imparted to the respective reel by a respective drive motor at the start of the speed change; a circuit which produces a total moment of inertia signal corresponding to the total moment of inertia of the respective reel with the tape wound thereabout, in response to the detected radius, acceleration, tape tension, and torque; a torque calculating circuit which produces a torque signal corresponding to a desired torque necessary to maintain the

Abstract: When a plurality of shunt motors connected in parallel are used for driving an electric railcar, the differences in the characteristics of the motors introduced during the manufacturing thereof causes the armature currents to vary greatly even when they are running at the same speed. To control the field current by means a single device, therefore, the armature currents must be corrected by armature choppers. In order to fully recover the kinetic energy possessed by the electric railcar, the present invention automatically corrects for the difference in the characteristics of the shunt motors so that the required braking force is uniformly borne by each of the shunt motors.

Abstract: A reel-tension motor drive system embodies circuitry for the instantaneous calculation of the coil diameter of one reel from the instantaneously derived coil diameter of the other reel, thereby requiring the use of only one step velocity signal, the latter preferably on the winding side.

Abstract: A control for a digital cassette tape drive maintains constant linear tape velocity at the playback head, constant tape tension, provides compensation for inertial imbalances and provides for minimal stop time. Constant linear velocity is obtained by computing actual velocity at the head and using the computed information to control takeup motor speed. Tape tension control is achieved by energizing the payout hub drive motor with a voltage which is a function of hub rotational speed and motor current.

Abstract: This invention relates to a device for driving a flexible protection element rolled up on a winding shaft, the free end of the element being connected through one or a plurality of flexible bonds to a winding drum. The winding drums and the winding shaft are coupled through reversible reduction gears to corresponding electric motors and to a pair of electromagnetic brakes of the type operating by current deficiency. The first motor is adapted to rotate in a first direction for rolling up the flexible bonds. The second motor is adapted to rotate in a direction opposite to that of the first motor for rolling up the flexible protection element. Electrical or electronic means are provided for actuating anyone of the two motors and simultaneously energizing the two brakes. This invention is applicable notably for driving protection tents, canvasses and the like in glasshouses, greenhouses and the like.

Abstract: Apparatus is provided for controlling a web transport system, such as a tape transport, of the type having supply and take-up reels for supplying and taking up the web, respectively, a tension control circuit for controlling the supply and take-up tension of the web, a web drive, such as a capstan, and a sensor for sensing the movement of the web as it is driven. The control apparatus includes a web drive detector for detecting the operation of the web drive and, particularly, the speed at which the web drive is driven. A comparator coupled to the sensor and the web drive detector compares the actual speed at which the web moves and the speed at which the web drive is driven to indicate when the speed at which the web moves differs from the speed at which the web drive is driven, such as when the web slips with respect to the web drive. An adjusting circuit coupled to the comparator adjusts the tension control circuit when the web speed differs from the web drive speed.

Abstract: A control circuit for apparatus stretching a web between intake, discharge, and intermediate pulling stations (20-1, 20-2, 20-3). The circuit includes a first signal generator (32) for providing a signal to the intake discharge station (20-1) corresponding to the desired speed of the web at that station. A multiplier (40) alters the first signal in accordance with the amount of overall stretching, or stretch ratio, desired in the apparatus. The multiplier provides a second signal to the discharge station (20-3) corresponding to the speed of the web at the discharge station necessary to obtain the overall stretching. A second signal generator (48-66) subtracts a selected amount of the difference between the first and second signals from the second signal to provide a third signal to the intermediate pulling station (20-2) that distributes the overall stretching in the apparatus between intermediate zones formed by the adjacent pulling stations.

Abstract: Apparatus for winding a preselected, programmable amount of tape under a predetermined level of tension is described. The tape is automatically placed under the predetermined level of tension prior to actually winding the tape onto the hub. The tape is fed at a variable speed according to a look-up table, while it is wound onto a hub, and is servoloop controlled so as to maintain constant tension on the tape as the speed at which the tape is fed changes.

Abstract: Apparatus and method for controlling the speed of a tape drive having an ingoing capstan and an outgoing capstan with a magnetic head therebetween. First and second phase lock loop servo-circuits for driving first and second dc motors which drive the ingoing and outgoing capstans, respectively. A stable reference oscillator providing the reference frequency to one of the phase lock loop servo-circuits and to another phase lock loop circuit which provides the reference frequency to the other phase lock loop servo-circuit. The feedback frequency in the third phase lock loop circuit is adjustable to control the difference in the two reference frequencies to the two servo-circuits for the purpose of controlling the difference in speeds of the ingoing and outgoing capstans.

Abstract: A tape tension sensor is provided to produce an electrical signal indicative of the tension of the running tape of a compact cassette in a tape recorder, and this signal is processed to derive a high frequency component representing the variation in tape velocity. A tape-contactable member is driven by a control signal which is produced on the basis of the high frequency component. In a first embodiment, the tape-contactable member is electromagnetically operated by the control signal so that the member damps or absorbs the vibrations of the tape in the vicinity of the record/reproduce head. A low frequency component may also be derived from the sensor output to produce a second control signal. In the first embodiment, the second control signal is fed to a payoff reel drive motor so that the rotational speed of the payoff reel is controlled to maintain the tension of the tape constant.

Abstract: Device for the attenuation of the movement of the reel motors in recording devices during standstill of the tape capstan drive roller. The regulation of the reel motors proceeds during the normal run of the tape via the motor current and during the standstill of the capstan drive via the voltage which lies at the reel motors.

Abstract: A reel-to-reel constant speed tape transducer in which the torques of the reel motors are controlled to maintain the tension in the tape to the take-up reel substantially equal to or slightly greater than the tension in the tape from the supply reel. The speed of the take-up reel provides a measure of reel diameter to generate signals which control the torque of the reel motors.

Abstract: An apparatus for rapidly and positively stopping the rotations of first and second tape reels which are driven independently, without introducing slack or damages to a recording medium of a tape form wound by the first and second tape reels. The control system for this apparatus uses digital signals.

Abstract: A circuit for automatically disconnecting a shaft drive spinning a textile winding bobbin and automatically substituting a circumferential cylinder drive for the shaft drive is disclosed. The cylinder drive becomes effective a short time after the start of the textile winding process. A signal proportional to the torque of the shaft drive motor is stored in a storage amplifier shortly after the start of the winding process. If the continuously measured instantaneous current value of the shaft drive exceeds, when both drives operate in parallel, the stored current value, a command to switch off the shaft drive is given.

Abstract: A system for winding linear material, such as strands of molten glass, into a package includes a mechanism for collecting the strands, a motor for rotating the collecting mechanism, a drive mechanism for controlling the speed of the motor in proportion to the frequency of a signal applied thereto, and a digital frequency generator for producing such a signal. The generator permits an initial frequency and a rate of change of frequency to be manually selected so that the speed of the motor is periodically decreased to maintain a substantially constant circumferential speed of the package thereby keeping the strand under constant tension. The generator includes a mechanism for digitally storing a manually selected number and a mechanism for generating a signal having a frequency that is proportional to the stored number. A mechanism for periodically incrementing the stored number at a selected rate produces a changing frequency and hence changing motor speed to maintain constant strand tension.

Abstract: An improved drive for a magnetic data storage tape is described which features direct coupling of the tape from a machine to a file reel without interposition of vacuum buffers or spring loaded tension control devices. Control of the current supplied to motors driving the file and machine reels is performed by a microprocessor in response to information derived during an initialization routine performed at first mounting of a reel of tape upon the drive and in response to continuously generated velocity information generated by tachometers on the motor shaft. The absolute position of the tape can at all times be known to the microprocessor and the tension of the tape can be controlled by control of the supply of current to the motors. In a preferred embodiment, a solid state buffer memory is provided to accept data from a host computer during the time the tape drive comes up to speed.

Abstract: Two DC motors are driven by switching pulse drive circuits, and the switching on times of drive pulses are made to be out of phase with each other at the two switching pulse drive circuits. One of the two DC motors rotates rotary video heads, and the other drives a capstan of a video tape recording and/or reproducing apparatus. The drive pulses are preferably synchronized with horizontal synchronizing pulses of a video signal to be handled by the video tape recording and/or reproducing apparatus in order to avoid pulse noises.

Abstract: A tape-loading device in an apparatus for recording and/or reproducing information signals on and/or from a recording tape comprises a mechanism for drawing a portion of the tape out of a cassette and loading the portion along a specific tape path, a supply-side reel motor for driving a reel disc on a tape-supply side in the cassette, a takeup-side reel motor for driving a reel disc on a takeup-side in the cassette, and an electrical circuit operating when the tape-loading means draws out the tape to apply voltages to the reel motors on the supply side and the takeup side such that an equal rotational torque is produced in each of the two motors in the direction of winding up the tape.

Abstract: Method and apparatus for monitoring movement of tape in tape transport apparatus for reel/tape assemblies such as cassettes, using tape position determination algorithms for determining absolute values of tape position as tape is driven from reel to reel using numerical constants stored in memory and periodically measured reel rotational speed ratios. The apparatus incorporates a microprocessor based controller having a CPU and program memory unit storing programs operating the CPU under program control to make the position determinations based on inputs from pulse generators representing reel rotational speeds and numerical constants corresponding to each of a plurality of known types of cassettes, which constants are derived for the one of the known types of cassettes loaded in the apparatus.

Abstract: A system is described for holding the tension of a web substantially constant as the web is transported from a supply spool to a take-up spool. The rotation of each spool is controlled by a motor. A tension control circuit senses the currents in both motors and alters motor current so as to hold the sum of the motor currents at a substantially constant value. In this manner, the sum of the torques generated by the motors and their spools is held at a substantially constant value to thereby maintain web tension substantially constant as the radii of the spools change during web movement.

Abstract: A system for controlling the rotation of a motor comprises a detector for detecting the rotation of the motor, frequency discriminator for frequency discriminating the output of the detector, a loop filter comprising resistors and a capacitor which lowers the high-frequency components of the output signal of the frequency discriminator, a switching circuit which is connected to the output side of the loop filter, the switching circuit grounding the output side of the loop filter and discharging the capacitor of the loop filter in a state before starting of the high-speed rotation of the motor, and non-grounding the loop filter in a state in which the motor is undergoing high-speed rotation, and a motor driving circuit which drives the motor in accordance with the output signal of the loop filter through the switching circuit.

Abstract: Method and apparatus is disclosed for driving the take up and supply spools of a web transport system. The apparatus includes a pair of direct current motors, one for each spool, and a circuit for regulating the current in the two motors. The circuit senses the counter EMF across the takeup motor, and accordingly controls the current in the supply motor, in order to apply a proper dragging torque to the supply spool. In the event of a loss of power to the web transport, the two spools are brought to a stop in a controlled manner by electronic means.

Abstract: Method and apparatus for determining automatically the type of tape carrier introduced into a device designed for transferring a tape between two reels. Two positions of the tape are compared and a signal is generated which is representative of this comparison. The comparison signal is compared with an interval or a reference value and as a result of this latter comparison, the indication of the type of tape carrier is either corrected or not corrected.

Abstract: Apparatus and a method for controlling the operation of a fin winding machine. Various motor drives are utilized to regulate the speed of rotation of a heat exchange tube upon which fin is wrapped to regulate the speed of rotation of forming wheels for bending the fin to the appropriate configuration and to regulate the speed of rotation of slitter wheels for perforating the fin prior to bending. Sensing means are provided for determining the length of the fin strip within various segments along a fin route such that the motor speeds are all adjusted to maintain the desired amount of fin strip. Tension means are provided for maintaining constant tension of the fin strip regardless of the length of the fin strip in the appropriate segment. The various sensing means are cascaded such that a change in speed of one motor may affect a change in speed of another motor.

Abstract: A bidirectional tape reel brake has a spring loaded movable plate coaxially encircling a motor shaft and arranged to exert a braking force on the motor shaft in proportion to the spring pressure on the brake plate. A brake pad support plate is attached to an end of the motor shaft to position brake pads on the support plate between the movable plate and a fixed brake plate. A first spring is arranged to urge the movable plate toward the brake plate to clamp the brake pads therebetween. A plurality of supplementary or second springs are arranged to exert a supplementary braking force by providing additional spring pressure to the brake plate.

Abstract: A magnetic tape drive arrangement without pressure roller, having a signal generator which generates a signal T, derived from the capstan motor current and the capstan speed. The is proportional to the instantaneous torque exerted on the magnetic tape by the capstan, which signal T controls the supply and/or take-up motors in such a way that this signal is minimized, so that a slip-free magnetic-tape drive without pressure roller is possible.

Abstract: The position of the tape in a magnetic tape recorder is obtained by counting the pulses derived from the revolutions of a reel or spool. The ratio of the number of revolutions per minute of the reels and the total number of turns is determined by means of a test run; the counting process is linearized by means of these values.

Abstract: A tape tension control circuit for a helical scan video tape recorder is disclosed having a pair of tension sensors. A sensor output from a take-up (supply) side sensor is fed back to a take-up (supply) reel motor when a pinch roller and a capstan are driving a tape. When the pinch roller and the capstan are deactuated, the sensor output from the take-up (supply) side sensor is then fed back to a supply (take-up) reel motor.

Abstract: A reel motor control circuit for use in a tape recorder equipped with a pair of motors driving reels, respectively, is disclosed, by which the direction of tape transportation is determined by controlling conductions of transistors associated with the motor, respectively, and a possible loosening of the tape can be removed at a commencement of the forward or reverse reproducing operation of the recorder.

Abstract: A tape recorder control circuit for operating both right and left-hand drive motors and control solenoids. At the start of a play operation, both motors are operated at a normal speed to nearly instantly take up tape slack after which one motor is operated at normal speed and the other with a low torque to maintain a back tension on the tape. For operating the solenoids, a single circuit configuration is provided which instantly activates the solenoids when switching from the stop mode to the play mode but activates them only after a predetermined time delay when switching from the fast forward or rewind mode to the play mode.

Abstract: A capstanless magnetic tape transport system employs supply and take-up motors, the supply motor being employed as a drag motor. The supply motor is controlled to meter tape at a predetermined speed, and the take-up motor is of such design that, in response to a constant voltage applied thereto, it provides constant tension to the tape being metered.

Abstract: A method for controlling the transfer of a flexible web member from a supply reel to a take-up reel, according to which the rotational speeds of the supply reel and the take-up reel are measured and whereby the ratio between these measurements is established independently of the speed and direction of the movement of the web member. The method comprises the steps of storing reference information representing the characteristics of different types of reel and web, releasing the reference information corresponding to the reels and webs used, generating intermediate signals which represent the said ratio combining these intermediate signals with the released reference information and generating output signals in dependence upon the momentary position of the web in relation to one or other ends thereof, and using these output signals for the purpose of visually displaying the position of the web and/or of controlling certain operations of the apparatus.

Abstract: Apparatus for controlling the speed, direction and tension of tape transported between a supply reel and a take-up reel. First and second drive motors are coupled to the supply and take-up reels for applying oppositely directed torques thereto, thereby bi-directionally driving the tape between these reels and applying back-tension to the driven tape. A speed detector detects the transport speed of the tape and generates a speed control signal proportional thereto. Torque voltage generators are responsive to the speed control signal for generating first and second torque voltages which are determinative of the torques respectively applied to the supply and take-up reels by the drive motors, the first and second torque voltages changing differentially with respect to each other as the speed control signal changes.

Abstract: A tape drive including a drive motor; a take-up reel driven thereby; and a motor speed control system controlling the angular velocity of the drive motor for maintaining a substantially constant linear velocity of the tape as it is wound on the take-up reel, said control system comprising: a turns-counter counting the turns of tape as each is applied to the take-up reel; a presettable register; presetting means for presetting a predetermined number in said register at the beginning of a tape drive operation when the take-up reel is empty of tape; means for decrementing the register at a rate, with respect to the rate of application of turns onto the take-up reel, which is initially large during the application of a first predetermined number of turns, and which is subsequently reduced during the application of subsequent turns, to cause the contents of the presettable register to decrease in a non-linear manner with respect to the rate of increase in the number of turns applied to the take-up reel to approxim

Abstract: A tape drive for moving a tape with a prerecorded clock track past a transducer at a constant velocity. An output signal from a speed servo circuit controls the energization, and hence the speed, of a tape driving motor. It responds to a tape speed signal derived in part from a power supply voltage and a speed reference signal derived from the power supply voltage. Voltage variations and temperature-induced variations in the power supply have a minimal effect on tape velocity. Tension servo circuits control the power to a driven motor in response to the speed reference signal and the speed servo output signal thereby to maintain the tape under tension. A brake and park gating circuit slows the tape and maintains the tape under tension when it stops. The speed reference signal undergoes an exponential rise during starting operations to minimize acceleration.

Abstract: A control system is described for use in a web transport in which a web is advanced from a supply spool to a take-up spool by a pair of drive motors, the latter of which are actuated by a servo control. The system includes a variable gain network which enhances the gain of the servo system at very low speeds without sacrificing system stability at higher speeds, and a circuit for adding a hold-back torque to the motor driving the take-up spool to smooth its rotation under low torque conditions. In addition, the system includes a device for inhibiting the rotation of the spools when an operator has removed the web from the spools, thereby preventing the servo control from rotating the spools in an uncontrolled manner in response to inadvertent operator movement of one of the spools.

Abstract: Apparatus for maintaining constant tension on a web during movement thereof, e.g., during positioning original documents in an exposure station of a reproduction machine. The web is coupled between a take up reel and a supply reel, with each reel being driven by an electric motor. The two motors are energized by a signal from the same source, except that the signal applied to the supply reel motor is the derivative of that applied to the take up reel motor. In such manner, the supply reel is energized during periods of acceleration or deceleration of the web thereby maintaining constant tension on the web during positioning.

Abstract: High tape acceleration rates are achieved in an unbuffered, capstanless tape drive system by a tape motion control apparatus employing separate drive motors for each reel of a reel-to-reel tape transport. Tape moves from one reel past a read/write head and a tape tension sensor to the other reel, there being no tachometer in the tape feed path. A tachometer on one reel shaft provides a large number of pulses per revolution which pulses are counted by a counter; and a tachometer on the other reel shaft provides only one pulse per revolution, which pulse gates out the count then accumulated in the counter for actuating means to provide motor acceleration currents of a magnitude corresponding to said accumulated count according to a predetermined servo algorithm for controlling rotation of both reels. A tape radius constant corresponding to the actual length and thickness of tape in the system is calculated during initial wrap of tape onto the takeup reel.

Abstract: A system is described for controlling the speed and direction of rotation of first and second spools in a web transport system in which a web is advanced between the spools by first and second drive motors. The system incorporates a servo control which continuously reacts to variations in the speed of the spools so as to drive the spools at respective speeds whose sum is constant and proportional to a selectable control voltage. To achieve this result, the first and second spools, driven, respectively by the first and second drive motors, are coupled to means, such as a corresponding pair of servo generators, for generating electrical outputs representative of the direction and speed of rotation of the spools. A control voltage, proportional to the sum of the desired speeds of the two spools, is continuously and algebraically summed with the outputs of the two servo generators, the summed signal constituting a motor drive signal.

Abstract: Reproducing apparatus for magnetic tape in which the forward and rewind torques motors are series-interconnected to moderate their torques and limit the tape tension during play mode only, thereby eliminating the large heat-generating resistors required when the torque motors are parallel-connected by the conventional arrangement. Relatively small variable resistor means is provided in the power supply to the series-interconnected torque motors, enabling adjustment of tape tension in the play mode. In the specific embodiment illustrated, the variable resistor means comprises two individual resistors. Switch means selectively connects one or both resistors into the torque motor power supply circuit to keep tape tension within a predetermined range during play mode for different size tape reels.

Abstract: Disclosed is a tape-transport apparatus wherein a first brake is provided for a reel for winding a magnetic tape thereon, the reel being operatively coupled to a first DC motor; a second brake is provided for a reel for supplying the magnetic tape, the reel being operatively coupled to a second DC motor; means is provided which is adapted to impart the retarding force to the second DC motor when an electromotive force, which is generated by the rotation of the first DC motor due to its inertia whenever the power supply to the first DC motor is interrupted, is in excess of a predetermined level; and there is provided means which is adapted to operate the first and second brakes when the magnitude of the electromotive force reaches a predetermined value, thereby stopping the transport of the tape.

Abstract: A ribbon driving and tensioning apparatus includes a pair of identical mechanical assemblies connected to reversibly drive associated rollers which support a printing ribbon. Each assembly includes a bi-directional DC reduction motor the output shaft of which is connected through a friction clutch assembly to the supporting shaft of a roller. The roller shaft includes a brake for applying a resisting torque in a direction opposite to that of the shaft rotation. A switching assembly for reversing the current to the motors and thereby reverse the direction of drive of the motors includes a pair of reversing switches mechanically coupled to a lever adapted to be pivoted between a first and a second position by a strip actuator positioned on the ribbon. A strip actuator is positioned adjacent opposite ends of the ribbon such that the direction of travel of the ribbon is reversed when the ribbon is almost completely unwound from one of the rollers.

Abstract: Long and short term variations in the speed at which a magnetic tape is moved with respect to a read and/or write head are minimized by maintaining the product of the speed of the tape payout and take-up reels constant. In accordance with a preferred embodiment the rotational speed of the payout reel and the rotational speed of the take-up reel are sensed and effectively multiplied to derive a signal which is compared with a predetermined constant magnitude reference signal. The result of the comparison is an error voltage which is employed to energize and thus control the speed of the drive motor for the take-up reel.

Abstract: A dynamic brake for the supply reel motor of a tape transport. Upon power failure, the motor is coupled as a generator to supply current to a lamp, which functions as a substantially constant current load, and produces a substantially constant braking torque upon the supply reel.

Abstract: A method for controlling the transfer of a flexible web member from a supply reel to a take-up reel, according to which the rotational speeds of the supply reel and the take-up reel are measured and whereby the ratio between these measurements is established independently of the speed and direction of the movement of the web member. The method comprises the steps of storing reference information representing the characteristics of different types of reel and web, releasing the reference information corresponding to the reels and webs used, generating intermediate signals which represent the said ratio combining these intermediate signals with the released reference information and generating output signals in dependence upon the momentary position of the web in relation to one or other ends thereof, and using these output signals for the purpose of visually displaying the position of the web and/or of controlling certain operations of the apparatus.