Abstract: A tape driving apparatus includes both supply and takeup reel diameter detectors so as to compute the inertia of both the reels, wherein the acceleration/deceleration torque information spent in the acceleration/deceleration of the take-up reel is detected from the take-up reel torque information so as to compute the take-up reel acceleration/deceleration compensating torque from the acceleration/deceleration torque information, both the reel diameters, and the inertia information, and the supply reel torque is controlled with the information with the computed results and the back torque information proportional to the supply reel diameter being added to it. The the access property of the tape is thereby improved.

Abstract: The invention discloses a method and an apparatus for winding a cord continuously. A rotation of a winding bobbin around which a cord to be a tension member of a belt, is wound and detected directly or indirectly. A cord is forwarded in an axial direction of a winding bobbin at a pitch, which corresponds to a diameter of the cord, in relation to a rotation of a winding bobbin. The bobbin axis of the winding bobbin is rotated at a constant speed by rotation driving means so that the cord is wound around the winding bobbin. The rotation of the bobbin axis is detected by rotation detection means directly or indirectly. The cord is forwarded in the axial direction of the winding bobbin in relation to the rotation of the winding bobbin at a pitch which corresponds to the diameter of the cord by receiving signals from the rotation detection means.

Abstract: A tape transport apparatus is comprised of a friction type capstan servo block having a friction type capstan driven by a capstan motor controlled by a capastan servo circuit in response to a control signal for determining a velocity of the capstan and a pulse signal generated in response to a rotation of the capstan motor, a reel servo block having a supply reel and a take-up reel driven by a supply and take-up reel motor controlled by a supply reel and take-up reel control circuit respectively, first and second tape tension detectors for detecting tape tension of the tape locating between the capstan and supply reel and between the capstan and take-up reel respectively, a control voltage generator for generating a control voltage, a tape tension control data generating circuit having a memory, the memory having a plurality of back tension characteristics data each of which is changed in response to the pulse signal so that the back tension of the supply reel motor is controlled in response to an outlet sign

Abstract: A web drive cyclically moves a web a fixed distance. First and second spaced draw roll units include separate servo motors. Separate programmed controllers are connected to energize the servo drives with a time motion profile including acceleration and deceleration periods to move the web in a fixed time period. The one programmed controller generates the profile program each cycle during the execution of program to move the web the next cycle. The generated program is down-loaded to the second controller to duplicate energization of the second servo motor. A dancer unit between the drive rolls maintains the tension with a change in web length and includes a movable roll unit. A potentiometer sensor is coupled to the roll unit and establishes an output signal voltage proportional to the direction of the web change and to the length thereof.

Abstract: A method of controlling reel drive so that a magnetic tape is transported from one reel of first and second reels to the other between them at predetermined transport velocity including the steps of forming a control signal obtained by operationally determining predetermined expressions having functions of the rotational numbers of the two reels, indicating a variation in the turn numbers of the magnetic tape on the reels and of the winding radii of the reels and controlling at least one of the reels based on a comparison of the control signal with informations of rotational angular velocity of the one reel actually detected.

Abstract: Motor-control device for an image forming apparatus includes a motor, an encoder, a microcomputer, and a driving circuit. The encoder generates a pulse signal in response to rotation of the motor. The microcomputer includes a CPU, a RAM and a ROM. The CPU detects actual rotational speed of the motor based upon the pulse signal generated by the encoder. The CPU cyclically provides a driving signal by comparing the actual rotational speed with a predetermined target rotational speed of the motor. An operating cycle is proportional to a cycle of the pulse signal generated by the encoder. The driving circuit drives the motor based upon the driving signal provided by the CPU. The CPU determines the operating cycle based upon the predetermined target rotational speed. The CPU also determines whether the motor condition is normal or abnormal by comparing the driving signal with a predetermined reference driving signal.

Abstract: This invention relates to tape tension control in a device which has a capstan disposed between a supply reel and which transport a tape wound around the supply reel to the take-up reel. While the tape, mounted on the reels, is running, the tape speed is varied greatly, and during this speed change period, a tape tension variation between the supply reel and the capstan and a tape tension variation between the capstan and the take-up reel are found. From those tape tension variations, ratios of moments of inertia of the reels with the tape thereon to the tape radii are found, and according to the values of the ratios, the gains of the loops of the tension control system is adjusted.

Abstract: A tape traveling apparatus drives differentially a tracking control actuator and a tension control actuator by inputting simultaneously into a tension controller a tracking instruction signal inputted into a tracking controller, and variably adjusts an amplification of the tracking instruction signal inputted into the tension controller according to an output of a tension sensor for detecting a tension variation of a tape, thereby eliminating a differential error between the tracking control actuator and the tension control actuator.

Abstract: A controller for a winding machine, for controlling the tension of a work running from a feed roller to a winding beam. The controller comprises a speed ratio control unit having a high response speed to control exactly the respective rotating speeds of a feed motor for driving the feed roller, and a winding motor for driving the winding beam during the decelerating operation of the winding machine to maintain the work at a tension substantially the same as a predetermined tension for stationary operation during the decelerating operation of the winding machine. The controller reduces time necessary for stopping the winding machine to the least extent.

Abstract: A reel servo device for a video cassette recorder with a direct drive reel system, which carries out smoothly fast forward and fast rewind operations by distributing properly the load carried to the supply reel motor and the take-up reel motor. The current through the driving reel motor, is detected and supplied as a driving current of a magnitude proportional to the detected voltage to the other reel motor so as to rotate it in the direction of the tape movement.

Abstract: In a capstanless tape transport, practice of the invention provides substantially constant tape tension when tape is spooled from a supply reel to a take up reel over the tape's entire length, for either direction of tape travel. The tape velocity is maintained constant by a closed loop velocity servo controlling the current applied to one of the reeling motors, and the tape tension is maintained substantially uniform by applying a current derived in an open loop manner to the other motor, such that the sum of the currents to the two reeling motors equals a constant.The invention may be implemented either utilizing analog control or digital control of the reeling apparatus.

Abstract: A tape-tension control circuit for preventing an over-voltage from being applied by a phase locked loop (PPL) to drive a reel motor for use in a video recording/reproducing apparatus upon selection of an initial search operation. First multiplexer 10 outputs selectively a frequency signal according to the rotation of a take-up reel or a supply reel thereof. Control circuit 20 synthesizes the output of the first multiplexor with a bias voltage to drive the reel motor at the least speed. Second multiplexor 50 receives at each input the synthesized output of the control circuit 20, and the phase-locked-loop output of the first multiplexor 10. The second multiplexor 50 consequently outputs control signals to control the operation of motor driver coupled to a reel motor. Comparator 40 compares the synthesized output of the control circuit 20 with a specified reference voltage, thereby controlling the multiplexing operation of the second multiplexor 50.

Abstract: A device for running a tape-shaped medium convoluted across two reels, including a rotation drive for rotating a reel, a detector for detecting the rotating state of said reel, data-for-control holding device for holding data for control of the rotation drive, an output control circuit for causing the data-for-control holding device to output the data for control of the rotation drive, in response to the rotating state of the reel detected in the detector, and a drive control circuit for controlling the drive state of the rotation drive in response to the data for control of the rotation drive.

Abstract: A magnetic tape contact printing apparatus includes a rotational transfer drum for driving a copy tape in intimate contact with a mother tape on which information signals are recorded, these information signals being transferred from the mother tape to the copy tape. The apparatus also includes a sensor for sensing the rotational speed of the rotational transfer drum, a pair of reel discs each mounting a copy tape supply reel and a copy tape take-up reel about which the copy tape is wound, and a pair of reel disc motors for driving the reel discs. A pair of tensioning devices respectively tension the copy tape running between the copy tape supply reel and the rotational transfer drum and between the latter and the copy tape take-up reel.

Abstract: The invention relates to a method and apparatus for making low inertia motors useful under circumstances where the load exerting drag on the motor during start-up acceleration may be different from time to time. A ramped drive current as opposed to a conventional constant current limit signal is applied to the motor. The invention is particularly useful, for example, in magnetic tape drives which must adapt to variations in drag between one tape cassette or cartridge and another.

Abstract: A system including a self-contained electromechanical control mechanism and method of operation is provided for controlling the tension and lateral position of a web or tape as it is motor driven to pass over a series of rollers. This device comprises mechanical means in which two pairs of rollers are mounted in upper and lower positions on a metal frame, the upper rollers being disposed on a pivotted plate having cantilever projections to which piezoelectric load cells are attached. Changes in the tension of the web or tape is sensed by the load cells connected in a bridge circuit, which sends a signal to a microprocessor, the output of which controls the driving motor or a clutch to compensate for the change in tension. Simultaneously, the position of the tape is controlled by another device, whereby the edge of the tape or a line on the tape passes through additional sensing means. This sends another signal to the microprocessor which energizes a linear actuator to correct the misalignment of the tape.

Abstract: To control the draw exerted on a web which is being fed to the rolls of a web processing machine, a strain wave gear power transmission device has its power input shaft driven by the main drive shaft of the machine and its output shaft coupled to the rolls including the nip rolls of the machine which draw the web. The wave generator (W.G.) shaft of the device is driven continuously in a single direction and at a higher rotational speed relative to the power input shaft. Encoders provide concurrent pulses at rates indicative of the main shaft and W.G. shaft speeds. The ratio of the pulse ratio is determined and compared to a stored value which corresponds to percent of draw desired. Any resulting error signal is used to change the speed of the W.G. shaft and output shaft. High encoder pulse rates provide for resolving small speed and draw errors. The output shaft of the transmission drives groups of rolls of the machine by way of a plurality of belt drive systems.

Abstract: A web feed printing press, more especially a rotogravure press, has a longitudinal shaft for driving printing units and a device for driving the web draw rolls. In order to achieve a simpler design without any direct mechanical connected between the draw rolls and the longitudinal while still ensuring accurate drive operation the drive device for the pair of draw rolls comprises a main motor and an auxiliary motor each with an adjustable speed of rotation. A differential drive has two inputs and one output. The speed of rotation of the main motor is varied in a way dependent on the speed of rotation of the longitudinal shaft and the speed of rotation of the auxiliary motor is varied in accordance with the speed of rotation of the longitudinal shaft and of the tension of the web of paper to be printed.

Abstract: Apparatus for controlling tension in a movable web includes a frame supporting a web supply roll, and a torque motor connected to the supply roll. The web is supported along a web path. Web position is measured by a dancer roll biased against the web. A signal representative of the web position is generated and supplied to a control system, which receives the position signal and generates in response a torque signal representative of a torque value to be applied to the roll to cause the actual web position to equal a nominal position. The control system is connected to the torque motor to control the motor in accordance with the torque signal.

Abstract: A control system has a detecting block for obtaining a detected signal corresponding to a controlled variable of a controlled system and a controlling block for supplying the controlled system with a control signal corresponding to the detected signal. The controlling block comprises an error block for producing an error signal corresponding to the detected signal at a detecting block, a memorizing block having a plurality of memorized values corresponding to the error signal, an output block for producing the control signal by mixing the error signal and one or more memorized values of the memorizing block and a adapting block for changing the number of a plurality of memorized values of the memorizing block according to a frequency of fluctuation of a disturbance source.

Abstract: A device for running a tape-like medium between a pair of reels in accordance with one of a plurality of tape-running modes having different tape running speeds has the following constituents: a reel driving apparatus for rotating the reels; a circuit for detecting the states of rotation of the reels and for generating reel rotation data; an instruction circuit for giving an instruction for changing the tape running mode; a holding means or memory for holding the reel rotation data when the tape running mode is changed in response to the instruction given by the instruction circuit; and a control circuit for controlling the reel driving apparatus in accordance with the reel rotation data held by the memory, for a predetermined period after the changing of the tape running mode effected by the instruction circuit.

Abstract: In a reel to reel tape transport system for determining the radii of the reel to reel tape by generating a series of forward and reverse pulses from a brushless DC motor driving the reel to reel tape, generating a forward series of pulses when said tape is turning in the forward direction and a reverse series of pulses when the tape is turning in the reverse direction, using a state machine to determine a forward or reverse revolution of the tape despite tape reversals before the completion of the revolution, and a counter and decoder for decoding the output of the state machine to provide an accurate determination of one revolution of the brushless DC motor.

Abstract: Disclosed is a printer which drives a drive motor for a type wheel or a carriage therefor by a signal derived by processing a first digital signal resulting from a position error signal and a second digital signal which is delayed by a predetermined time period. The digital signals can be processed by an LSI chip which assures a highly reliable, low cost and compact printer.

Abstract: A motion control system for a reel to reel web transport apparatus which maintains a controlled tension on a web as it is transported between reels. The motion control system includes brushless direct current motors directly coupled each reel. A magnetic hysteresis brake is coupled to each reel by means of respective one-way clutches. During transport of the web from reel to reel, a magnetic hysteresis brake applies a controlled torque only to the reel supplying web. Thus, a controlled tension is maintained on the web at all times, even during loss of power to the DC motors.

Abstract: A tape feed control device is configured to detect resolutions of respective reels so as to supply respective reel motors with tension currents i.sub.t1 and i.sub.t2 for setting a tape tension to establish a predetermined tape tension of a tape extending between the reels, and so as to supply the reel motors with acceleration and deceleration currents i.sub.s1 and i.sub.s2 based on an acceleration/deceleration current ratio .alpha. to transport the tape. In this fashion, a desired tape speed is obtained, maintaining a constant tape tension.

Abstract: The invention relates to a tape transport mechanism in which two reels are respectively driven by different motors, thereby transporting a magnetic tape from one reel to another reel by passing through the portion of a read/write head without any variation in tension. At the initial stage to transport the magnetic tape, an acceleration time from a stop state of the tape until a tape speed reaches a reference speed and an average tension deviation to be applied to the magnetic tape during this time are obtained. Correction values to correct variations in run characteristics of two reel drive systems are calculated by use of the acceleration time and the average tension deviation. Upon next and the subsequent magnetic tape transport, currents to be supplied to the motors to drive two reels are controlled by use of the drive current command values corrected by those correction values.

Abstract: The tape speed control apparatus according to the present invention is provided with drum period detecting means which detects the speed of the rotary drum by detecting pulses (SWP) for switching the heads of the rotary drum, speed setting means for generating speed data for the rotary drum, the speed data being set from outside, and comparator means for comparing the speed of the rotary drum as set by the speed setting means with the speed of the rotary drum as detected by the drum period detecting means, data on the difference between the set speed and the speed of the rotary drum being supplied to a reel servo, so that the travel speed of the magnetic tape is controlled and kept constant thereby.

Abstract: A cassette tape loading apparatus is provided, by which a cassette tape wound around a pair of reels of a tape cassette is drawn from the tape cassette, wrapped around a rotary head drum of a cassette tape recorder and then recorded and/or reproduced, in which revolution speed of a reel motor rotating each of the reels is detected by a revolution speed detector and the detected revolution speed is compared with a reference revolution speed, and then on the basis of the compared results, the revolution speed of the reel motor is controlled to prevent the tape from being supplied from one reel to the other reel upon tape loading or tape unloading, whereby the position at which the tape is wrapped around the rotary head drum can be prevented from being displaced considerably and the tape can be protected from being damaged.

Abstract: Apparatus for tensioning tape extending between two reels in a tape transport system having servos for controlling the velocity and position of the reels, includes position servo loop for maintaining the first reel in a fixed position. A velocity servo loop controls the other reel for taking up slack in the tape between the reels and applying a relative force on the tape once the slack has been taken up. The velocity servo is limited in the amount of current applied to the motor driving the take up reel by a signal provided by a tension servo connected to the position servo associated with the other reel. In particular, the tension servo responds to the amount of current applied by the position servo for applying a motor-current-limiting signal to the velocity servo system. When the position servo is applying minimal current to the fixed-position reel (when the tape is slack), a relatively large amount of current is allowed to go to the take up reel.

Abstract: A reel to reel web transport apparatus includes an adaptive control which eliminates the necessity (1) for mechanical or vacuum web buffers, (2) for a capstan or tachometer to meter or control web velocity; and (3) for a tension transducer to control web tension. The web transport apparatus includes supply and takeup reels driven by brushless direct current (DC) motors. Hall device assemblies associated with the brushless DC motors provide Hall signals which are used during a learning mode to determine several unknown parameters for servo control of the web transport apparatus.

Abstract: An adaptive rewind system is described for use in tape drive apparatus or other apparatus involving roll goods which are movable between a supply reel and a take-up reel. The system includes (1) comparison means for (a) comparing the voltage at the motor driving the supply reel to a supply reference voltage, and (b) comparing the voltage at the motor driving the take-up reel to the supply reference voltage, and (2) control means adapted to maximize the velocity of the roll goods while being wound from one reel to the other. The control means is adapted to drive at least one of the motors with a voltage essentially equal to the supply reference voltage, while the voltage at the other motor does not exceed the supply reference voltage.

Abstract: An adaptive velocity change profile for control of a video tape transport apparatus during a cue mode. The tape transport apparatus moves the video tape to a cue point in the shortest time available by adapting a deceleration velocity change profile to the actual ballistics of transport of the tape. When in a cue mode, the transport uses a commanded velocity signal generator to produce digital numbers which are applied as a reference speed signal to a velocity servo driving the takeup reel of the transport. For distances separating a selected frame location on the tape from the cue point greater than a predetermined distance, the commanded velocity is the maximum available from the transport. For distances to the cue point less than the predetermined distance, the commanded velocity is generated from an adaptive cue profile which decelerates the transport of the tape quickly as the selected frame location approaches the cue point without overshooting the mark.

Abstract: A closed loop, high-speed tape transporter (10) includes a vacuum supply (11A), a first vacuum column (40) operatively connected to the vacuum supply (11A) and positioned upstream from a pick-up head (100) and downstream from a tape bin (64) for receiving the loop of tape and exerting a vacuum-induced holdback tension thereon, a second vacuum column (50) operatively connected to the vacuum supply (11A) and positioned downstream of head (100) and upstream of the tape bin (64) for exerting a vacuum-induced pull forward tension on the tape in opposition to the holdback tension exerted on the tape by the first vacuum column (40). A motor-driven capstan (60) is positioned intermediate the pick-up head (100) and the second vacuum column (50). Capstan (100) is driven at a constant speed equal to the ideal reference tape duplication speed. Tape drive capstans (62A) and (70A) cooperate with the first and second vacuum columns (40) and (50) for moving the tape.

Abstract: A digital servo apparatus according to the present invention latches a count output of a counter (11) for counting reference clock signals in response to output of a speed detecting pulse from a speed detecting pulse generator (10a) in a latch circuit (141), thereby to latch the count output latched in the latch circuit (141) in another latch circuit (142) upon output of a subsequent speed detecting pulse. The digital servo apparatus further latches the count output of the counter (11) in a latch circuit (16) in response to output of a phase detecting pulse from a phase detecting pulse generator (10b). A comparator (15) compares difference between the count outputs latched in the latch circuits (141) and (142), so that the compared output difference and the count output latched in the latch circuit (16) are converted into analog signals to be sampled and held respectively thereby to produce a speed error signal and a phase error signal, which are added up to be supplied to a driving circuit (22).

Abstract: A tape speed control system for a magnetic tape recorder allows a magnetic tape to be fed at any desired speed in a fast feed mode operation. In a fast feed mode operation, rotation periods of take-up and supply reels are detected and one of them is weighted relative to the other. The sum of the weighted and non-weighted periods is compared with a predetermined reference period and the resulting difference signal is used to control drive motors associated with the respective reels, thereby causing the tape to run at a desired speed regardless of the roll radius thereof built up on the take-up reel.

Abstract: The present invention relates to a gondola lift having two parallel suspension haulage cables between which the gondolas hang. The two cable loops extend between two stations and each cable is driven by a direct current electrical motor, the two motors being identical and having separate excitation circuits. The armature windings are connected to the same power supply source by two armature circuits including identical resistors which provide an armature voltage drop and a reduction in speed for restoring identical power outputs of the two motors when one of the cables is in advance. The mechanical connections between the cables and the motors include gear boxes, the high speed shafts therefrom being coupled by a control clutch.

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 ribbon tension control for controlling the tension of ribbon traveling between a rotating supply spool and a rotating take-up spool varies the amount of braking torque applied to the supply spool to hold ribbon tension constant as the distribution of ribbon between the spools changes. A generator rotationally coupled to the supply spool produces braking torque to resist the rotation of the spool when the generator windings are electrically loaded. The loading of the generator is controlled by processing feedback signals emitted by the generator to provide periodic load switching signals. Processing of the feedback signal is accomplished in the exemplary embodiment by a drag lookup table which is addressed by the feedback signal. The drag lookup table produces a duty cycle value which is used to determine the duty cycle of the switching signal, which, in turn, controls the electrical loading of the generator.

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: A printing belt extends around a rotatable cylinder having independently rotatable belt drive sprockets at the opposite ends thereof. A torque-assist drive connected with the cylinder is selectively operable for imparting supplemental traction to the belt for preventing relative slippage between the belt and drive sprockets.

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: 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: A magnetic tape in a reel-to-reel magnetic apparatus is transported directly from a supply reel to a take-up reel without a mechanical buffer or a vacuum column buffer.Separate drive motors are coupled to the respective reels and driven by predetermined target signals.Tape roll radii on the respective reels are determined from the amount of tape movement, that is, rotation angles of the reels and a known tape thickness, and reel moments are determined from the tape roll radii to determine a total amount of tape wound on the reels, that is, a reel status amount.During the tape transport, the tape roll radii and the reel moments change from time to time. Operation band widths or dynamic responses of the reel drive systems are equalized in accordance with the change of the tape roll radii and the reel moments so that the reel drive systems are cooperatively controlled.

Abstract: A tape transport system has reduced unreeled tape length by employing only one tape-deflecting bearing on each side of the read/write head. These bearings are fixed in position, but capable of pneumatically sensing tape tension. This tape tension is sensed at both bearings, and used to counteract the effects of stiction at the head.

Abstract: A digital ramp function generator controls the speed of a motor drive system by initial contouring according to an arithmetic progression up to the intended ramp rate, and by final contouring according to the same arithmetic progression in reverse, thereby to reach the intended speed (by acceleration, or by deceleration). The digital ramp function generator is established at the intended ramp rate and contouring effects by a programmable controller programmed by the operator.

Abstract: A programmable controller including coil diameter calculator and strip speed derivation and inertia compensation is associated with a reel system for the generation in normalized digital form of the coil diameter of the reel instantaneously to allow initial calibration between successive coil winding and unwinding operations and automatic generation of a current reference for reel motor drive control.

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: A method and system for detecting tape attachment to a machine reel of an automatically threading magnetic tape system. During the threading process, a file reel is rotated to allow a sufficient length of tape to be unwound therefrom, which length of tape eventually attaches to the machine reel after being automatically threaded through the desired tape path. The rotation of the file reel is maintained during this threading process by delivering current pulses to a file reel motor. These current pulses are counted per unit time. As soon as the tape attaches to the machine reel, the machine reel begins to pull the tape from the file reel, thereby eliminating the need to deliver current pulses to the file reel motor, at the same rate as needed prior to tape attachment. A change in the rate of the current pulses delivered to the file reel motor signals a tape attached condition.

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.