Abstract: In a tape transport apparatus, a first servo feedback loop is provided for correcting tape tension by adjusting the rotation of a tape reel in response to the sensed position of a tension arm that engages the moving tape. A second feedback loop senses the rate of change in the position of the tension arm and responsively damps the tension arm position changes by means of a lead circuit which causes a torque motor coupled to said pivotable arm to move in opposition to the tension arm position changes.

Abstract: Hitherto, in the tension control for a reel, it has been impossible to exceed the tension controlling range of about 1:10 which is determined by the tension controlling range of a single DC motor, so that for the reel which requires a tension controlling range over 1:10, a plurality of DC motors have been combined and used or the gear ratio between the reel and the DC motor has been changed to date.In this invention, attention is paid to the fact that undesirable phenomena such as a change in characteristic due to an armature reaction, and deterioration of rectification which are caused by setting the field system to a low level can be sufficiently suppressed by limiting the setting and controlling range to the low region of an armature current.

Abstract: A hard copy recorder is provided in which paper or film is moved along a paper path by a motor-driven roller. A tension-measuring dancer measures paper or film tension. The position of the dancer is sensed by an optical sensor, which produces a signal representative of paper or film tension. The paper or film tension signal is used to selectively couple one signal from a number of sources of predetermined different frequencies to the motor to control its speed in accordance with the sensed paper tension.

Abstract: In a feeding apparatus wherein a web contained in a supply portion is taken up onto a reel, whereby the web is fed along a predetermined path, there is provided control means for rotatively driving the reel by a motor and controlling the driving current of the motor so as to reduce the rotational speed of the reel when the web in the supply portion draws near its terminal end.

Abstract: A regulation device for the rotary drive of a warp beam of a weaving machine for producing as uniform as possible a tension force on an unwinding material or group of warp threads conducted to a weaving device and then to a fabric take-up device. A tachometer is associated with a power regulator arranged ahead of the motor of the rotary drive as a momentary value transducer and comprises a generator for generating a signal corresponding to the tension force or tensile stress in the material or warp threads as well as a further generator for generating a signal corresponding to the take-up speed of the fabric being woven from the unwinding material or threads. These two signals are connected to a multiplier stage whose output signal is conducted to the power regulator of the rotary drive as a reference value.

Abstract: A batcher and the like is illustrated for utilizing torque control rather than speed control to vary the packing ratio of the rolls of a surface wound cloth roll. A phase shifting differential transmission is controlled by a condensor in series with the armature of a field wound D.C. motor in a drive between the rolls responsive to cloth tension to maintain such tension substantially constant.

Abstract: A stock reel having a variable speed electric reel drive motor and a speed control potentiometer operated by a stock loop control arm for producing a variable control voltage correlative with the angular position of the control arm. The control voltage from the control potentiometer is compared with a reference voltage and an input voltage correlative in amplitude with the difference between the control voltage and the reference voltage is applied to a motor control unit to drive the motor when the control voltage exceeds the reference voltage. The reference voltage is selectively adjustable to vary the angular position at which the control voltage exceeds the reference voltage, to thereby adjust the operating angle of the control arm. The amplification of the input voltage applied to the motor control unit is adjustable to vary the range of control arm movement required to produce a preselected change in motor speed.

Abstract: A device for controlling a speed of rolls of a rolling mill is disclosed which includes means for reducing an amount of drop of the speed of the rolls and a speed restoration time when a work to be rolled is introduced between the rolls.

Abstract: A system capable of unbuffered transfer of magnetic tape between a take-up reel and supply reel comprises a control unit connected through a mode switching device to a respective linked error device and pulse width modulator, arranged to drive a respective take-up or supply reel motor. A tachometer monitors the amount of a pre-determined length of supply spool tape transferred to the take-up spool and the control unit accordingly evaluates proposed reel motor current levels. The mode switching device operates each motor in velocity or acceleration mode. In the velocity mode a phase locked loop connected to the tachometer and a control frequency output provides an error signal which can be applied to the selected motor current level. In the acceleration mode a motor current sensor output is compared with the proposed current level to derive another error signal which can be applied to the selected current level.

Abstract: In a submerged scraper conveyor (10), an automatic voltage control system controls the speed of variable speed drive (32), in turn the speed of follower sprocket (22) and in turn the speed of drag chain (16) as a function of the torque on the headshaft (21). The tension on endless roller chain (36) is monitored by load cell (40) as indicative of the torque on the headshaft (21) and a standard process control signal is generated therefrom. The speed of variable speed drive (32) is varied as a function of the measured torque between a lower speed drive limit and an upper speed drive limit.

Abstract: A programmable controller which generates a digital normalized diameter signal and a digital normalized reel strip velocity signal is adapted for the generation of inertia compensation either with a constant torque, a constant horsepower, or a maximum torque reel system.

Abstract: In a roll film carrier for rewinding the roll film wound on a supply reel onto a take-up reel there are provided a signal generating means which detects the rotation of the supply reel shaft and outputs a corresponding signal, a means for generating a pulse synchronously with the passage of the roll film and a means for controlling the driving of the roll film through comparison of the number of pulses generated in the signal generating period of the signal generating means with a predetermined number and it is so arranged that the driving of the roll film is stopped when the number of generated pulses has agreed with the predetermined number.

Abstract: A supply reel servo for a tape transport in which a motor-driven capstan of low inertia draws tape past a cylindrical scanning drum includes a tension servo arm which provides a signal denoting tape tension in a loop adjacent the supply reel. This signal is compared with a reference to develop an error signal to control the supply reel motor. The reference is modified in response to a signal which represents the energization of the capstan motor and accordingly the torque output thereof so as to provide automatic compensation for variation in tape tension at the scanning drum.

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: 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: 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 catenary-like section of traveling web material hanging between a support point and a stepping motor-driven reel rotating to collect or dispense the material is maintained by regulating the stepping motor rate of rotation in accordance with a control signal output of an ultrasonic transducer operating in the pulse/echo mode to continuously monitor the distance between the low point of the catenary-like section and the transducer. A microcomputer connected between the transducer and the motor accelerates and decelerates the rate of stepping motor rotation in accordance with a predetermined program to maintain the catenary section during changes in the distance between the section low point and the transducer.

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: A stringed musical instrument is provided with an automatic self-tuning device which tightens or loosens those of the instrument's strings which may be out of tune. Each string is provided with an independent automatic tuning device and all of the devices are operated simultaneously on demand to instantly and automatically reset the tension of the strings as required. Each of the devices includes means for sensing the tension of its associated string and means for comparing the sensed tension with a reference tension corresponding to the desired tuning for the string. Means are provided for increasing or decreasing the string tension in response to the nature and magnitude of the compared tensions.In an alternate version, string tension is sensed and a visual indication is given of an out-of-tune condition. The instrument is tuned in this embodiment manually.

Abstract: The disclosed motor control device is responsive to control pulses received from a remote transmitter to provide switched duty cycle controlled power to the electric motor which drives the model, and provides neutral and fully proportional forward and reverse speeds while using only a single radio frequency channel. The controller is small in size and weight, is efficient, dissipates very little power, and employs no servo driven elements. The circuit is constructed to ensure motor shut-down in the event of loss of transmitter signal, or of receiver failure.

Abstract: An electric motor for a magnetic tape recorder comprises an electrically insulating disk-shaped stator with a plurality of flatwise coils, a rotary shaft rotatably extending through the stator, and a first disk-shaped rotor of soft iron with a multi-pole annular magnet and a second disk-shaped rotor of soft iron rotatably extending through the shaft on both sides of the stator. A pulley is fixed on the shaft below the first rotor to drive capstans, and a reel disc or a pinion is coaxially connected to the second rotor to drive a take-up reel for forward play. In a fast forward feed mode, the first and second rotors can be mechanically interlinked. Alternatively, an electromagnetic solenoid may be used to take out a torque from the first rotor by engaging an idle roller with a roller fixed to the rotary a shaft above the pinion or to apply a pressure to the second rotor to increase the friction between the second rotor and an adjacent shoulder on the shaft.

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: An open loop tension servo uses digital circuitry to automatically control motor torque and thus tape tension in, for example, a tape recorder, without the need for a tension sensor. To this end, the tape pack diameter of a tape takeup or supply reel is digitally computed, thus determining the motor torque required to maintain the requisite tension on the tape during the record or replay operating mode. A binary number indicative of the instantaneous tape pack diameter is generated and stored until a new number is available. Each stored number is supplied to D/A converter means formed of selected parallel or series resistor, arrays, wherein specific resistor combinations are successively selected to provide a corresponding change in resistance commensurate with the changing pack diameter represented by the changing size of the binary number.

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: A tape fast-forwarding and rewinding apparatus comprising a rotation driving circuit for driving a motor for rotating a take up or supply reel so that the tape travels at a first fast-forwarding or rewinding speed, or travels at a second fast-forwarding or rewinding speed, the latter speed being faster than the former, a detection circuit for detecting the radii of wound tape respectively on the take-up and supply reels, and a memorizing circuit for memorizing the ratio of the radii of the wound tape detected by the detection circuit, while the tape is travelling at the first fast-forwarding or rewinding speed.

Abstract: Reels of magnetic tape used in a reel-to-reel drive system suffer from an inter-layer slip if the reel has gone through environmental changes. This slip will cause errors to occur in the reading of the tape, since a constant tension and velocity and an accurate position is required in the reel-to-reel drive. To check whether the tension of the tape needs to be refreshed, the end of the tape is firmly held while the hub is driven in a reverse direction against the firmly held end of the tape. A detected reverse rotation indicates an inter-layer slip condition. The tape tension must be refreshed by unreeling the tape and rereeling with the correct tension applied. The reel of tape is then ready for operation.

Abstract: A stringed musical instrument is provided with an automatic self-tuning device which tightens or loosens those of the instrument's strings which may be out of tune. Each string is provided with an independent automatic tuning device and all of the devices are operated simultaneously on demand to instantly and automatically reset the tension of the strings as required. Each of the devices includes means for sensing the tension of its associated string and means for comparing the sensed tension with a reference tension corresponding to the desired tuning for the string. Means are provided for increasing or decreasing the string tension in response to the nature and magnitude of the compared tensions.In an alternate version, string tension is sensed and a visual indication is given of an out-of-tune condition. The instrument is tuned in this embodiment manually.

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: 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 tension control system for use with a device which includes at least one roll over or around which a web or strand of material passes, a tension responsive transducer associated with the roll, a reference tension selector, a drive unit for effecting movement of the web or strand over or around the roll, and a tension controller associated with a tension control roll, the tension controller responsive to the outputs of the transducer and of the reference tension selector for controlling the torque applied to the tension control roll in order to control tension on the web or strand, the improvements comprising a control circuit connected between the transducer and the tension controller including an error limiter circuit responsive to the outputs of the transducer and of the reference tension selector to produce an error signal, the control circuit having circuit elements responsive to the error signal and connected to vary the torque applied to the torque control roll in a manner to maintain the web or stran

Abstract: A control system for a slitter-rewinder apparatus which forms a web of material into a plurality of individual rolls, the web being unwound from around a supply core and slit into strips which are rewound about a plurality of individual product cores. The slitter-rewinder apparatus has at least one takeup roller adapted to slidably receive the product cores there about. The supply core and the takeup roller are rotatably supported in spaced apart relationship with a portion of the web extending therebetween, around at least one idler roller and past a plurality of knives which cut the web into strips. The slitter-rewinder apparatus further has a first controllable motor for rotating the takeup roller and a second controllable motor for rotating the supply core. The control system includes a sensor for detecting the rotational speed of the product cores.

Abstract: A direction reversing apparatus for a rotary motor of a microcassette tape transport includes a motor (14) having substantially the same characteristic for the forward and reverse motor rotation directions for driving a recording tape, and a motor controller (12) for setting a motor speed to a given speed. The reversing apparatus further includes a switch (16) coupled between the motor (14) and the motor controller (12) for reversing the direction of rotation of the motor (14).

Abstract: A function generator (25) receives the signal (svm) representing the speed of rotation of a motor (13) and works out EN=CN+f (vm), f (vm) being a single-valued and monotonic function of the real speed vm of the motor and CN being worked out by computer means (24) so that: CN=EN-f (VM), VM being the nominal value of the speed of rotation of the motor. The latter is fed by a signal which is a function of EN. The reference information f (VM)=IC is worked out from an item of error information which is a function of the deviation between the real speed (vb) and reference speed (vp) of a tape (10) driven by the motor, the rate of variation of IC having a maximum value limited in absolute value.The device is suitable for subordinating the rate of travel of a tape carrying sound to the frequency of a pilot signal.

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 back spacing apparatus for a transcribing machine comprises a first means for providing a first signal (a) corresponding to the period of rotation of a supply reel or a take-up reel, a drive source for rewinding a tape toward the supply reel and a second means for providing electric energy (Tm.times.V) corresponding to the period (Tm) of the first signal (a) to the drive source for rewinding to vary the r.p.m. of the supply reel at the time of rewinding the tape toward the supply reel or the period of the rewinding operation according to the first signal (a). The magnitude (Tm.times.V) of the electric energy is varied in accordance with the period (Tm) of the first signal (a) for making the length of the tape rewound toward the supply reel substantially constant irrespective of the diameter of the tape rolled on the supply reel.

Abstract: Disclosed is a system for more precisely controlling the speed of a magnetic tape transport motor in an information storage apparatus of a magnetic tape type, by including a program for controlling the speed of the magnetic tape transport motor in the microprogram for controlling the information storage apparatus of a magnetic tape type.

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 printer having an ink ribbon with a bidirectional ribbon drive in which a pair of stepper motors have their windings cross-coupled so that a drag current flows through one stepper motor to apply drag torque to the ribbon when the other stepper motor is operated for driving.

Abstract: A motor drive system having a direct current, shunt motor utilized in a web coiling operation and operated in a tension control mode includes circuitry to automatically provide compensation for inertial effects of the drive and the web coil during periods of acceleration and deceleration.

Abstract: System for maintaining a preselected constant torque on a loaded reel of a winding mechanism. The system includes a d.c. motor wherein both the armature and field windings are adapted for independent rotation about a common axis. The field winding is coupled to the reel so that the reel rotates at a velocity proportional to that of the field winding. A drive motor establishes a constant speed rotation of the armature winding. A torque control drives constant currents through the armature and field windings of the motor. The amplitudes of the armature and field currents are preselected so that a constant torque is maintained at the reel irrespective of variations of the load.

Abstract: A mooring winch system in which automatic mooring duty is performed by a winch having an AC motor fed from the supply via a converter which includes a DC to AC inverter, the convertor producing a balanced three-phase square, quasi-square, sinusoidal or quasi-sinusoidal output. The motor thus can stall indefinitely, be driven in the sense of rope payout by tension force in the mooring rope, or run in the opposite sense to recover rope, without exceeding its rated temperature for that duty. Rope recovery is adequate both for normal duties and also where higher speeds of recovery are required and rope tension is maintained substantially constant throughout.

Abstract: A web fed press has at least one press unit including a first web driving means driven by a first motor. Downstream from the press unit is a second web driving means, such as nip rolls, driven by a second motor. Encoders are associated with the motors to produce pulse trains which are compared for motor speed relationship. If the relationship is not correct, the energization of the second motor is varied to correct the error. The relative web speed at the two locations is adjusted by effectively varying the number of pulses per revolution produced by the encoder for the second motor.

Abstract: A blower motor providing vacuum as, for example, for a magnetic tape handler, is programmed to provide a constant vacuum in an environment of changing altitudes. The blower motor is controlled by a pressure transducer which speeds up the motor as the altitude is increased and slows down the motor as the altitude is decreased.

Abstract: Apparatus for controlling the material tension in a knitting machine, particularly a circular knitting machine, by employing a permanent magnet-excited d.c. motor and an associated circuit to drive a motor torque-dependent material take-off mechanism through the generation of a variable magnitude, pulsed current to power the motor. The magnitude of the current may be set by the operator, with the pulse/no pulse ratio of the current being controlled by the operating mode of the knitting device. In a preferred embodiment, an additional circuit monitors the operation of the current control circuit to detect and signal malfunctions.

Abstract: Means and method for controlling the power delivered to the shaft of a DC motor when the field of the motor becomes saturated and prevents control of armature voltage by the field of the motor. The method involves the step of increasing the current in the armature by an amount corresponding to the decrease in the voltage of the armature caused by a decrease in the speed of the armature during saturation of the field. Increasing armature current is effective to maintain power output of the motor constant. If the speed of the armature increases after the occurrence of saturation, the voltage of the armature increases, such that the method includes the additional step of decreasing armature current in proportion to the increasing armature voltage to maintain constant power output of the motor.

Abstract: A torque compensation system is disclosed for d.c. motor drives using field weakening for speed control. A diode switching matrix and a static divider are connected so that the divider receives signals which are functions of motor armature current and speed respectively, and delivers at its output a signal which is proportional to motor torque for adjusting the speed reference to the motor.

Abstract: A purely electrical tension control system utilizing the characteristics of a shunt motor coupled with the supply reel. In a recording or reproducing mode, the reel drive motor is forced to rotate in a direction opposite to its normal direction of rotation, thus producing a counter electromotive force and torque for rotation. The counter electromotive force is detected and employed to control the motor torque to thereby maintain a fixed tape tension.

Abstract: A tape transport control system suitable for use in tape recording apparatus which utilizes supply and take-up reels onto which the tape is wound. The control system is coupled to both the supply and take-up reels so as to generate detection signals which represents the rotation of the reels. The circuitry utilizes the detection signals to determine the point at which each of the reels in nearing its end, and sends a control signal to the tape transport circuitry to stop the rotation of the reels.

Abstract: Shunt motor field control for setting motor torque (and thereby controlling tension on a reeler or the like driven by the motor) comprising thyristor control gated by a comparator with a ramp-form voltage input compared to a reference level established by an operator setting of a potentiometer. The ramp-form voltage is generated by charging and discharging a capacitor and provides a spike voltage through the comparator when the reference level is exceeded. Means are provided to compensate potentiometer and capacitor tolerances to match potentiometers to the torque control setting range.