Abstract: This invention pertains to processing continuous webs such as paper, film, composites, and the like, in dynamic continuous processing operations. More particularly, it relates to accumulating limited lengths of such continuous webs and to controlling tension in such continuous webs during the processing operation. Both tension control and limited accumulations are achieved in a festoon system by connecting a corresponding festoon to actuator or the like, sensing variables such as position, tension, velocity, and acceleration parameters related to the web and the festoon, and providing active force commands, in response to the sensed variables, to cause translational movement, generally including a target acceleration, in the upper festoon rolls to control tension disturbances in the web while providing limited accumulation of a length of the web. In some applications of the invention, the festoon control system is used to attenuate tension disturbances.

Abstract: An apparatus for calibrating a tension transducer for a web includes a pair of nip rollers and a motor for driving at least one of the pair of nip rollers, the motor having at least one roller output being a function of at least one of a motor torque and a motor velocity. A web tension transducer roll is located upstream of the nip rollers, the web tension transducer having a tension output being a function of the actual web tension of the web. A processor receives the at least one roller output and the tension output, the processor calculating a tension correction value as a function of the at least one roller output and the tension output.

Abstract: A device for applying tension to yarn or the like, the device including a stator and a rotor. The rotor includes an outer spool around which, in use, yarn or the like is passed and an inner part including a cylindrical sleeve-like portion. The stator includes outer pole piece defining apparatus extending between the outer spool and the sleeve-like portion of the inner rotor part, inner pole piece defining apparatus surrounded by the sleeve-like portion of the inner rotor part and apparatus for producing a magnetic flux between the inner and outer pole piece defining apparatus.

Abstract: A method for controlling electrically actuated weft brakes for automatically adjusting mechanical tension of a weft thread in textile machines with mechanical insertion, comprising the steps of: generating and modulating an excitation current of an actuator of an electrically actuated brake. The above step is performed with a device which comprises a control chip which is sensitive both to variations of mechanical tension measured on the left thread and to an actual value (v) of a travel speed of the weft thread during insertion; the control loop is adapted to recondition a reference parameter of the braking action, determined by the control loop on the basis of a reference tension and a measured tension, with a multiplication factor which is represented by a decreasing function [f(v)] of the actual value (v) of the travel speed of the weft thread.

Abstract: This invention pertains to processing continuous webs such as paper, film, composites, and the like, in dynamic continuous processing operations. More particularly, it relates to controlling tension in such continuous webs during the processing operation. Tension is controlled in a dancer control system by connecting a corresponding dancer roll to an actuator apparatus or the like, sensing variables such as position, tension, velocity, and acceleration parameters related to the web and the dancer roll, and providing active force commands, in response to the sensed variables, to cause translational movement, generally including a target acceleration, in the dancer roll to control tension disturbances in the web. In some applications of the invention, the dancer control system is used to attenuate tension disturbances. In other applications of the invention, the dancer control system is used to create tension disturbances.

Abstract: In a tape transport for recording and/or reproducing signals by means of a recording medium using separate winding motors for driving the winding plates, the drive of the winding motors servo units is constructed as open-loop control devices and/or closed-loop control devices. Such servo units can advantageously be used for open-loop control and/or closed-loop control of the drive of the winding motor even during a braking operation.

Abstract: The invention concerns a procedure for correction of error of speed and mechanical related error, particularly in the thickness of a fiber band in a textile machine, especially stretch machines. The purpose of the invention lies in the correction of the speed related errors in measurement signals from an instrument of the textile machine. This purpose is achieved by each measurement value generating a respective corresponding inverse and speed related correction value. By means of this correction value, each measurement value can be correspondingly and individually corrected.

Abstract: An automatic control system for controlling the firmness of a fluid supported mattress of a bed assembly. The control system includes a motorized fluid pump, a control unit for operating the pump to adjust the firmness of the air mattress, a hand held remote control unit for actuating the control unit, and a transceiver system for transmitting information signals between the hand held unit and the control unit. The air control system provides for independent control of both bladders in a two bladder air mattress from a single unit, and allows a user to consistently set the firmness of each mattress air bladder to a desired value. The air control system includes an air pump specially designed to minimize transmission of motor noise into the environment.

Abstract: A method is disclosed of temporarily speeding up delayed carriages on a return side of an endless loop of driven carriages in a linear motor web tenter.

Abstract: An apparatus and method are disclosed for controlling the motion of a machine system so as to cut individual lengths from a web having graphics on predetermined web positions and which allows the use of an inexpensive AC induction motor. An AC induction motor has an output power shaft for imparting the motive force necessary to drive the machine system, such as a web feeding system. A sensor is operatively coupled to the AC motor for determining the position of the motor during system operation. A controller is operatively connected to the sensor and motor and forms a closed loop control circuit. The controller changes the feedback loop characteristics of the closed loop control circuit during a stop, hold or start condition of the motor. By adding an externally generated compensating signal to the input of the feedback loop, the controller also minimizes acceleration error.

Abstract: An object of the present invention is to provide a drive system having a simple structure, which is capable of synchronously moving travellers, having high positioning accuracy and reducing the manufacturing cost and operating noise. A pair of guides are provided on a base in a first direction. A pair of travellers are capable of moving in the first direction alongside the guides. A first rotary guide is provided to one of the travellers. A second rotary guide is provided to the other traveller. A first tension member is tensionally engaged with the rotary guides, one end section is extended from the first rotary guide and fixed to the base, the other end is extended from the second rotary guide in the opposite direction and fixed to the base.

Abstract: A time-based control system (10) for controlling a process incorporating external devices using a predefined response profile (13). The response profile (13) is continuously compared to the actual response of the controlled device (11). A plurality of sensor modules (24) is used to monitor the actual magnitude and direction of change of selected quantities during the process. If the response it outside the user-defined maximum allowable error, appropriate measures are taken to either correct the error, halt the process, or proceed with the process in a time-based mode. The proper response and detection of errors of the controlled device (11) is independent of load, rate, temperature and other external stimuli. The time-based control system (10) can detect errors caused by higher level equipment such as the sensor modules (24). Thus, the time-based control system (10) can detect when any portion of the time-based control system (10) or the controlled device (11) malfunctions.

Abstract: A speed control apparatus for a rotary motor includes a motor for rotating at a speed based on a torque command and which outputs a present angular position and a present angular speed of the motor. A speed measuring unit is provided for obtaining a speed error representing the difference between a reference angular speed and a present angular speed. A speed controller is provided for outputting a current command for controlling a rotational speed of the motor. A learning compensator is provided for correcting an effect of a disturbance expressed as a function of an angular position and an angular speed applied to the motor, via a repetitive learning process using the reference angular speed, any one of the speed error from the speed measuring unit and the current command output from the speed controller and the present angular position of the motor, for removing a high frequency noise generated in the repetitive learning process, and for outputting a resultant disturbance correction value.

Abstract: When a processor sets a current instruction value and a rotating direction of a motor, two analog instruction signals of a positive polarity and a negative polarity are obtained after completion of a D/A conversion, the analog instruction signal of the negative polarity is selected by an instruction in the CW direction, and the analog instruction signal of the positive polarity is selected by the instruction in the CCW direction. The analog instruction signal of the polarity selected is added to a motor current detection signal which was negatively fed back by an adding circuit, so that an analog deviation signal is derived. A pulse width modulating circuit section outputs a PWM pulse in the CW direction for the negative polarity of the analog deviation signal and outputs a PWM pulse in the CCW direction for the positive polarity.

Abstract: A process for reducing the friction between a rotating head drum and a tape-shaped recording medium which surrounds the head drum for recording and/or playing back information. In order to shorten access time to information stored on the tape-shaped recording medium, some recorders have the recording medium mounted in a cassette which remains threaded even during rewinding, and surrounds the head drum in the same way as in the play and search modes. Because the tape remains threaded during rewinding, such recorders, also called full-loading recorders, suffer from increased friction between the rotating head drum and the tape moving in the reverse direction. To reduce friction, the speed of rotation of the head drum is increased by a factor, preferably a factor of 2, during rewinding.

Abstract: A velocity control method for a rotary motor and an apparatus adopting the same estimates and corrects a disturbance applied to the rotary motor to improve a velocity control characteristic. The disturbance is expressed as a function of an angular velocity and an angular position via a simple calculation process. The velocity control apparatus includes a learning compensator for receiving a velocity command, angular position information and the output of a velocity controller and correcting an effect of the disturbance which is expressed as a function of the angular velocity and the angular position, in addition to a general velocity control loop of a rotary motor composed of a velocity controller, a current controller, a motor and a velocity measuring unit. The learning compensator stores one period of the output of the velocity controller at a steady state of the velocity control loop and obtains a correction value using the stored value and the previous output value.

Abstract: This invention pertains to processing continuous webs such as paper, film, composites, and the like, in dynamic continuous processing operations. More particularly, it relates to controlling tension in such continuous webs during the processing operation. Tension is controlled in a dancer control system by connecting a corresponding dancer roll to a servo motor or the like, sensing position, tension, and velocity parameters related to the web and the dancer roll, and providing active gain force commands to cause translational movement in the dancer roll to control temporary, short-term tension disturbances in the web. In some applications of the invention, the dancer control system is used to attenuate short-term tension disturbances. In other applications of the invention, the dancer control system is used to create short-term tension disturbances.

Abstract: A method and apparatus are disclosed for joining a drive band to the driven element of a servo-controlled precision motion system. A vibration dampening clamp assembly absorbs unwanted vibration energy. The clamp assembly utilizes energy absorbing molded grommets which mechanically isolate the driven element from the band. A threaded fastener passing through an axial bore in each of two energy absorbing grommets is used to join two halves of a clamp assembly. The grommets are preloaded at assembly using threaded fastener and a nut to compress each grommet to a known compression prior to tensioning of the drive band. Upon final tensioning of the band drive assembly, the grommets are brought to a final compression value.

Abstract: The invention generates a correction signal for the command input to an automatic feedback control system or servomechanism used to control the torque, force, or tension acting upon an object or payload that is stationary or is moving relative to the motor housing. The correction signal is proportional to the sum of the torque acceleration and velocity errors. The "torque acceleration error" is the product of the inertia, referred to the motor shaft, and the motor acceleration. The "torque velocity error" is the product of the external damping factor acting on the motor shaft and the motor velocity. The correction is required when the steady state value of motor torque output is sensed and used for the negative feedback signal; this measurement is accomplished with relative ease.

Abstract: This invention pertains to processing continuous webs such as paper, film, composites, and the like, in dynamic continuous processing operations. More particularly, it relates to controlling tension in such continuous webs during the processing operation. Tension is controlled in a dancer control system by connecting a corresponding dancer roll to a servo motor or the like, sensing position, tension, and velocity parameters related to the web and the dancer roll, and providing active gain force commands to cause translational movement in the dancer roll to control temporary, short-term tension disturbances in the web. In some applications of the invention, the dancer control system is used to attenuate short-term tension disturbances. In other applications of the invention, the dancer control system is used to create short-term tension disturbances.

Abstract: A doffing mechanism wherein a cloth roll doffer (C) is normally carried in aligned laterally spaced relation to the cloth roll with a motor which are actuated by manually raising the cloth roll engaging means to forcefully move the cloth roll engaging means for doffing the full cloth roll into a cart positioned beside the takeup rolls for receiving and carrying away the cloth roll. A DC motor (E) drives the takeup, and a DC motor control has a bridge rectifier (F) in an armature circuit of the DC motor supplying full armature current to the motor during doffing.

Abstract: A self-propelled robot includes an electrical cord mounted on a spool for being drawn-in or drawn-out. A sensor senses a rate at which the cord is drawn in or drawn out and actuates a motor connected to the spool for applying a rotary force to the spool to control the cord tension.

Abstract: A constant tension is maintained on cord of a robot by determining whether the cord is being extracted or retracted and the extent of such extraction or retraction, and increasing or decreasing a spring force applied to the cord by an amount suitable for maintaining a constant tension on the cord.

Abstract: A cable reel system for use in conjunction with a mobile installation movable relative to a fixed base station and being connected to the fixed base station via a cable, the system comprising a reel on which the cable is stored, the reel being connected by a motor shaft to an AC motor which drives the reel via reduction means to pay-out cable whilst the mobile installation moves away from the base station and to reel-in cable whilst the mobile installation moves towards the base station, the reel system further comprising sensing means located adjacent said motor shaft and operable to provide a signal representative of the position of the motor shaft, and a controller, which receives the signal and calculates a torque demand signal, the controller further continually varying a stator current of the motor in response to cable paying-out or reeling-in operating conditions pertaining at a given instant by using the torque demand signal to calculate and supply phase currents to the motor to provide a required tor

Abstract: A drive control system for a centrifugal used in, for example, a sugar refining operation, optimizes the deceleration and plow-out phases of its operation based on the torque characteristics of its particular drive motor. This is achieved by providing a centrifugal having a pulse-width modulated (PWM) frequency-modulated drive controlled by a programmable logic controller (PLC) running a ladder logic program. The ladder logic program implements a regenerative braking loop which complements the dynamic braking characteristic curve of the drive motor, thereby obtaining an optimal amount of braking torque for the motor over a wide range of motor revolutions or frequencies. Preferably, the system also implements a dynamic plow-out control for the motor when in plow-out mode to enable the centrifugal to be plowed-out in a minimal amount of time.

Abstract: The tension of a strip can be controlled with high responsiveness and high accuracy despite its drastic external variation by threading the strip (1) between a transportation roll (2) and a movable transportation roll (10) and moving the movable transportation roll (10). The movable transportation roll (10) is mounted on one end of an arm (11), which is mounted for a swing motion around a supporting shaft (12), a torque around the supporting shaft (12) is generated in the arm (11) by an arm driving motor (14) connected directly to the supporting shaft (12), thereby applying a tension to the strip (1). The angle of swing motion of the arm (11) is detected by an arm angle sensor (16), and the tension of the strip (1) is detected by a tension sensor (15). The torque to be generated in the arm (11) is corrected in accordance with the detected angle and tension, whereby the strip tension is controlled for a target tension.

Abstract: A magnetic tape transport having a pair of reel motors for bidirectionally driving a tape between a pair of reels within a cassette housing, and a pair of tension control transistors for controllably varying supply voltages across the respective reel motors. For holding the tape under tension when it is at rest, against the possibility of tape displacement regardless of varying tape roll diameters on both reels, the output pulses of a tape speed sensor are directed through a bidirectional counter into a digital to analog converter, so that the latter provides a voltage output that varies linearly in magnitude as the tape travels from one extremity toward the other. This variable voltage output from the converter is applied through a tension control circuit to the pair of tension control transistors whenever the tape is stopped. Standstill tape tension is thus controlled by varying the voltages impressed to both reel motors according to the current ratio of tape roll diameters on both reels.

Abstract: A method and apparatus is disclosed which reduces tape stiction during tape acceleration and deceleration. Tape tension is adjusted to eliminate the effects of tape stiction when the tape is either accelerated from a stationary position to a steady state velocity, or decelerated from a steady state velocity to a stationary position. This method uses tape tension, tape velocity, and tension reference profiles stored in a microprocessor to dynamically adjust the tape tension during tape acceleration and deceleration. The tape tension is adjusted as a function of tape velocity by the use of both a current generated by the tension reference profile and a feedforward current. The feedforward current is determined by the sum of the tape velocity and tape tension profiles. This dynamic adjustment of tape tension essentially eliminates tape stiction in tape start and stop operations.

Abstract: A portable motorized system of pulleys and cable which moves a three dimensional, or conventional target around a predetermined path. The purpose of this system is to simulate, through movement, the actions of an animal during hunting conditions. This system allows the user, to shoot at a target which moves and changes directions, while standing in one place. The system is suspended by attaching screwhooks into fixed objects such as trees, poles, buildings etc. A motor assembly which is attached to one of the supports turns a drive pulley. The cable and target are moved through a series of idler pulleys, by the drive pulley, around a closed circuit. A hand operated ratchet is utilized at another support location to apply tension to the system. The tension causes the system to be fully suspended from the supports. The motor is powered by a twelve volt battery, a switch and fuse are also incorporated.

Abstract: A motor control system for controlling a plurality of drive motors in a web tensioning system includes individual motor control circuits for each motor in the system. The web tensioning system includes a main exit drive motor and a plurality of helper drive motors. A single tensiometer is positioned near the exit motor to sense web tension at this point. Each helper motor control circuit is connected to this exit tensiometer to receive the exit tension as a tension feedback. Based solely upon this feedback value and a speed feedback from the associated motor, each motor control circuit is programmed to independently provide tension based control for its associated helper motor to compensate for its proportionate share of system induced drag on the web, resulting in uniform tension on the web throughout its path. Each motor control circuit can be switched between the tension based control and a speed based control format.

Abstract: A wire tensioner maintains wire in a winding machine at a substantially constant tension during the process of winding coils for electrical components such as armatures. The tensioner has a pulley wheel that is driven by a bidirectional drive unit. During operation, the pulley wheel either feeds wire toward a workpiece or draws wire back, depending on the nature of the tension correction required.

Abstract: In a video tape recording and/or reproducing apparatus, a tape tension servo-system detects tape tension between a supply reel propelled by a voltage driven motor and the head drum to provide a corresponding detected tension signal supplied to a processor which is periodically interrupted for providing a control signal proportional to any deviation of the detected tape tension from a desired value and further for providing differential and integral control signals determined from the proportional control signal at successive interruptions and which are combined to form a control voltage signal for the supply reel motor. The processor is desirably constituted by a universal pulse processor and a central processing unit. The tape tension is detected by an angularly movable arm carrying a post about which the tape is wrapped sufficiently to ensure good compliance.

Abstract: Method and apparatus for detecting breakage in a yarn strand being wound onto a yarn support member rotatably driven by a DC motor and having a closed-loop motor control system for maintaining a desired velocity of the motor and for signaling commutation of the phases of the motor during the yarn winding operation. The closed-loop motor control system monitors the signal conduction angles delivered to commutate the phase windings of the motor, detects a sudden minimum preestablished decrease in the monitored conduction angles, and generates a control signal in response to a sudden decrease in the conduction angle resulting from a yarn strand breakage. The control signal may be employed to stop current supply to the motor.

Abstract: A speed control assembly for a rotatable web winding apparatus comprising a dancer engaged with a web of material wound about the winder apparatus for displaceably responding within a predetermined range of dancer positions to tension variations in the web; a first control signal generating device for generating a first control signal in response to dancer displacement from a predetermined centered position, the ratio of dancer displacement to the first control signal being variable over the range of dancer displacement positions; and a dancer response rotation control device for rotationally accelerating the winding apparatus in response to the first control signal.

Abstract: An electrically operated driving shaft control device includes a casing having a driving shaft vertically journalled therein and a driving means for rotating it. A movable plate member has a first end with an upward projecting plate and a bearing seat with two first oval-shaped openings on both sides. A second plate provided on the movable plate has a first end distal from the projecting plate and a second end fixed in the casing. The second plate has a second oval-shaped opening and two threaded hole on both sides of the oval-shaped opening. The driving shaft has one end connected to the driving means and another end passing through the bearing seat of the movable plate member and the second oval-shaped opening of the second plate. A guiding roller is fixed to the driving shaft on the second plate. A rope encircles the guiding roller and connects to a blind. A means for breaking an electric circuit when a predetermined tension of the rope is reached during rotation of the driving shaft.

Abstract: A remote control device for an installation of electrical toys on a circuit comprises a radio emitter (400) for emitting different radio-electric signals (b) selected by the user and a fixed radio receiver (450) for detecting and transmiting the radio-electric signals to an electronic device (270) which interprets the signals and triggers a control device (275). Specifically, the radio signal (b), which is emitted by the radio emitter, comprises a repetition of a word composed of a series of presences or absences of electric pulses. The word is formed according to an associated coded signal (a) and in accordance with the user's selection.

Abstract: A motor controller provides a digital monostable circuit which generates a control signal indicating whether a field coil within a motor should be turned on or off. Two registers are provided within the digital monostable to store values indicating a fixed off time and a minimum on time. These registers can be loaded with selected values by a microprocessor or other controller. The stored values are selectively loaded into a counter which, when the field coil current reaches a preselected level, turns the supply to the field coil off for a time corresponding to the off time value, then on again for a period at least as long as the minimum on time value. The values in the off time and minimum on time registers can be changed to suit operating conditions of the system, and the controller can be operated in either PWM or open loop mode.

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 reel motor braking apparatus for a video cassette tape recorder which can perform the braking of a supply reel and take-up reel speedily even if the termination of a tape has failed to be detected due to a failure of a termination sensor or a poor quality of tape. In the apparatus a control signal is applied to the control terminals (SC,TC) of a supply reel motor and take up reel motor at the time of completing a Fast-forward or rewind operation that is inverted by the hardware.

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: A sphere which may be rotationally displaced by manual action, protruding from a control panel, is mechanically connected for resolving its rotary motion into motions about two axes perpendicular to each other, for control of the direction and speed operation of a video recorder and playback equipment. When any of several particular rotary displacements of the sphere have taken place, a controllable brake system bears on the mechanical coupling between the sphere and at least one of in the electronic transducers to exert a brake torque to simulate an index position. One such position is a neutral setting or "rest position". The y axis is used for gradual speed change and the x axis is used for stepwise speed change. The axis for gradual speed change has an initial threshold on each side of the rest position to determine direction. On the other axis, the speed steps may be separate for each direction, respectively on opposite sides of the rest position.

Abstract: Hitherto, in the tension control for a reel, it is 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 a gear ratio between the reel and the DC motor has been changed for many years so far.In this invention an attention is paid to the fact such that the unpreferable phenomena such as a change in characteristic due to an armature reaction, and deterioration of rectification or the like which are caused by setting the field system to a low level can be fairly suppressed by limiting the setting and controlling range to a low region of an armature current.

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 spooling mechanism has a chuck that is coupled to a spool for rotating the spool to wind a length of web material onto the spool. Torque is transmitted from a drive shaft to the chuck through a spring coupled to the shaft and the chuck. A transducer measures the angular relationship between the shaft and the chuck throughout a range of relative angular positions therebetween. The transducer provides a signal indicative of that angular relationship, and the signal is transmitted to a controller that regulates the torque applied by the drive shaft. The position of the chuck relative to the drive shaft during web winding operation is a function of tension transients in the web. Since the system adjusts the torque of the drive shaft as a function of the angular relationship of the chuck and drive shaft, the system is effective to reduce tension transients in the web being wound onto the spool.

Abstract: A stock feed apparatus for feeding strips of stock to or from a stock processing machine to maintain a loop in the stock. The feed means is arranged to feed stock to or from the loop at speed correlative with the amplitude of a control voltage applied to the motor control. The stock loop sensor produces a first digital signal when the loop exceeds a first limit and a second digital signal when the loop exceeds a second limit. A loop control circuit is operative in response to the first digital signal to apply a control voltage of a first preselected amplitude to the motor control to drive the feed apparatus at a first speed until the loop moves away from the first limit and responsive to the second digital signal to apply a control voltage of a second preselected amplitude to drive the feed apparatus at a second speed until the loop moves away from the second limit.

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 motion converter is disposed at the input to a work station to convert the constant velocity of sheet material as it is payed out from a roll into a cyclic, stop and go motion. The motion converter includes a pair of actuators containing electromagnets and these are alternately energized to attract the sheet material first against a contoured surface and then a flat surface. Sheet material accumulates in a serpentine path within the motion converter when attracted toward the contoured surface and it is expelled rapidly therefrom when attracted toward the flat surface. A programmed position control operates the electromagnets in response to position feedback signals from sensors on the motion converter.

Abstract: Apparatus for controlling the tension of travelling filamentary material such as that being unwound from a drum or spool. It comprises a three phase induction motor for turning the drum or spool modified to have a high resistance rotor providing a torque speed characteristic of falling torque with increasing speed. The motor drive, and torque in either forward or reverse drive, is controlled by a pair of thyristor banks selectively triggered for forward and reverse drive modes by error signals representative of variation in tension from the required 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.