Automatic And/or With Time-delay Means Patents (Class 318/364)
  • Patent number: 5426355
    Abstract: A system (20) for controlling deceleration of a motor (22) during an abrupt power-off condition includes a processor (40), a motor control circuit (50), and a secondary power source (70). During normal power-on operation and based on currently prevailing operation parameters, processor (40) routinely generates a contingent motor-governing deceleration signal for potential use in governing motor (22) should the power-off condition occur. In response to the occurrence of a power-off condition, motor control circuit (50) controls motor (22) in accordance with the contingent motor-governing deceleration signal to achieve orderly deceleration. Secondary power supply circuit (70) provides power to motor control circuit (50) during the power-off condition.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: June 20, 1995
    Assignee: Exabyte Corporation
    Inventor: James Zweighaft
  • Patent number: 5424622
    Abstract: A method for dynamically braking a motor, the motor having a plurality of terminals and receiving an input alternating current voltage waveform, by detecting the zero crossing of the input alternating current voltage waveform and for a plurality of position of the input alternating current waveform: sampling a voltage waveform appearing at a terminal of the motor to develop a sampled value for the position, comparing the sampled value for the position to a reference value for the position and setting a flag if the reference value for the position matches the sampled value for the position, introducing a delay period and generating a gating pulse to fire a silicon controlled rectifier to provide a pulse of braking current to the alternating current motor and then halting the braking of the motor if the flags for each of the plurality of positions are set. Also an electronic dynamic brake assembly operable in a SLAVE mode, a PRE-STOP mode, a HOLDING mode and a MASTER mode.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: June 13, 1995
    Assignee: Baldor Electric Company, Inc.
    Inventors: Kenneth Keller, Kenneth Hopwood
  • Patent number: 5374885
    Abstract: An apparatus for braking a rotary component of a fiber processing machine includes an asynchronous motor having a stator winding and an output shaft connected to the rotary component; a direct current generating device having an output connectable to the stator winding for applying an electric braking torque to the motor; and a switching arrangement for selectively connecting the stator winding to an alternating current source for normally driving the motor or to the output of the direct current generating device for electrically braking the motor.
    Type: Grant
    Filed: March 21, 1991
    Date of Patent: December 20, 1994
    Assignee: Trutzschler GmbH & Co. KG
    Inventors: Ernest W. Kuppers, Fritz Hosel
  • Patent number: 5001408
    Abstract: A control device is associated with a dynamic balancing machine for indexing a rotor being examined for unbalance. The control device determines the angular position of unbalance of the rotor during an unbalance measurement run and stops the rotation of the rotor while bringing it to a stop at an angular position related to the determined angular position of unbalance.
    Type: Grant
    Filed: January 31, 1990
    Date of Patent: March 19, 1991
    Assignee: Nagahama Seisakusho Ltd.
    Inventors: Yoshiaki Kyogoku, Katsumi Ajiyama
  • Patent number: 4928044
    Abstract: A spindle motor stop control device applies a reverse torque braking force to the spindle motor to effect stopping of the motor. A speed detector detects when the number of rotation of the motor has slowed to 1/n of a predetermined number of rotation and issues a detection signal. The time period beginning with the application of the reverse torque braking force until the issuance of the detection signal is measured. Then, a time period t=T/(n-1) is calculated and the reverse torque braking force is continued for the time, t, and then removed.
    Type: Grant
    Filed: December 19, 1988
    Date of Patent: May 22, 1990
    Assignee: Pioneer Electronic Corporation
    Inventor: Takahumi Shiba
  • Patent number: 4801856
    Abstract: A position of an actuation unit of a robot and a speed of a motor for driving the actuation unit are detected. A speed reference is produced on the basis of a deviation between a movement value and a position detected. Further, a torque reference is produced on the basis of a deviation between the speed reference and a speed detected. The motor for driving the actuation unit is subjected to current control. The magnitude of the torque reference is limited by a limiter. This limiter operates only when a command for allowing the robot to be subjected to emergency stop is received, and carries out limiting operation on the basis of a function which rises from the time point when the command is received.
    Type: Grant
    Filed: April 21, 1987
    Date of Patent: January 31, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroki Wajima
  • Patent number: 4767970
    Abstract: In a tape drive system, a dynamic brake control circuit provides dynamic braking for slowing and stopping an associated tape reel and motor system in the event of a power failure. Upon sensing a power failure, the electrical energy stored in a capacitor supplies electrical energy to enable the control circuit, which in turn supplies a controlled conductive path for the flow of a dynamic braking current due to the back electromotive force signal generated by the motor, to effect the controlled dynamic braking of the drive motor to a stop.
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: August 30, 1988
    Assignee: Ampex Corporation
    Inventor: David R. Rodal
  • Patent number: 4243919
    Abstract: An SCR motor speed control system is provided with circuitry for fast braking of the motor. The circuitry senses when it is desired to stop the motor and simultaneously short circuits the motor armature and applies half-wave rectified line voltage to the motor field windings.
    Type: Grant
    Filed: March 31, 1980
    Date of Patent: January 6, 1981
    Assignee: The Singer Company
    Inventor: Jack Brown
  • Patent number: 4195255
    Abstract: A circuit for electronically braking an AC motor. The circuit includes a controlled rectifying means for applying DC to the motor and a control means for turning the rectifying means on after deactuation of the motor for a timed interval determined by the charging rate of a timing capacitor through a variable resistance.
    Type: Grant
    Filed: December 5, 1977
    Date of Patent: March 25, 1980
    Assignee: Cole-Parmer Instrument Company
    Inventor: Emil J. Guttmann
  • Patent number: 4179646
    Abstract: A circuit breaker motor operator control circuit utilizes the voltage developed across a dynamic braking resistor during breaking of a permanent magnet DC motor to prevent re-energization of the motor until it has been braked to a virtual stop. The control circuit also includes a timing network operating to prevent continued pumping of the breaker operating mechanism by the motor operator should the operating mechanism for some reason fail to become charged within a prescribed time period.
    Type: Grant
    Filed: March 24, 1978
    Date of Patent: December 18, 1979
    Assignee: General Electric Company
    Inventor: Ronald R. Russell
  • Patent number: 4139810
    Abstract: The present invention is a device for stopping a passenger conveyor.A stop pushbutton is depressed to deenergize a driving motor for an escalator and an operating winding for an electromagnetic brake. The electromagnetic brake has a mechanical braking means whose operations is opposed by the magnetic force of the operating winding. Then two timing relays are energized and also the brake operating winding is reenergized through a variable resistor to brake the motor with a low braking force. The timing relays are successively picked up after predetermined time intervals to increase the resistance of the resistor to increase the braking force stepwise by decreasing the current and hence the magnetic force of the operating winding. When the escalator reaches a predetermined low speed, the brake operating winding is again deenergized to apply the rated braking force to the motor until the escalator is stopped.
    Type: Grant
    Filed: March 23, 1977
    Date of Patent: February 13, 1979
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasuo Ueki, Masaaki Nakayama