Relative Motor Speed Control Patents (Class 318/68)
  • Patent number: 6600278
    Abstract: A N pulse variable frequency drive for driving two or more motors that is the combination of two or more variable frequency drives with each drive driving an associated one of the two or motors. One application is a decanter centrifuge which has a main motor to drive the bowl and a back motor to drive the conveyor. One of the two variable frequency drives drives the main motor and the other drive drives the back motor. The variable frequency drives are connected to a common buss and to a N pulse phase shifting transformer.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: July 29, 2003
    Assignee: ABB Inc.
    Inventor: Jonathan Bretzius
  • Publication number: 20030048081
    Abstract: A surface clinging robotic device. The device includes a supporting structure or base, on which is mounted (a) a lead pivoting support surface, such as a pivoting wheel, and (b) two or more traction drives, such as drive wheels. Each of the traction drives are independently driven by a separate drive motor. A plurality of vacuum cups are mounted on the bottom of the base. The vacuum cups each have a low friction foot designed for movement over a surface with minimal friction while vacuum is maintained. The low friction foot portion is provided by a generally surface direction oriented C-shaped Teflon skin. The robotic device can move over gaps or obstructions in the surface without losing vacuum in all of the vacuum cups, using a fluid limiting valve at each vacuum cup to interrupt flow in the event of loss of vacuum in that vacuum cup.
    Type: Application
    Filed: September 9, 2002
    Publication date: March 13, 2003
    Applicant: ADVANCED ROBOTIC VEHICLES, INC.
    Inventor: Henry R. Seemann
  • Patent number: 6426600
    Abstract: Apparatus, such as a wheelchair (10) is proportionally controlled by output signals produced by an X-Y input device (26, 58, 90, 100, 110, 360, or 370), which may be attached to head (90), a hand (112) or some other body component, and which may be actuated by tilting. The output signals are conditioned prior to application to the wheelchair (10).
    Type: Grant
    Filed: March 10, 2001
    Date of Patent: July 30, 2002
    Assignee: Magitek.com,LLC
    Inventors: John L. Lautzenhiser, Lloyd L. Lautzenhiser
  • Patent number: 6404150
    Abstract: An electric vehicle accessory motor drive power supply system (40) that utilizes a single power supply design to provide efficient variable speed motor control to both brushless and brush-type DC motors (42,44). The power supply system includes at least one of each type of motor along with a first DC-DC converter (46) that provides operating power to the brushless motor (42) and a second DC-DC converter (48) that provides operating power to the brush-type motor (44). Both converters (46,48) have a power input (52) connected to the electric vehicle's high voltage bus (50) and each includes a data input (54) for receiving a speed control signal (SC) indicative of desired motor speed, as well as an output (56) for providing a motor drive signal to its associated DC motor (42,44).
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: June 11, 2002
    Assignee: General Motors Corporation
    Inventors: Thomas Wolfgang Nehl, Malakondaiah Naidu, Avoki Omekanda, Anita B. Rao, Lateef A. Kajouke, Mark M. Osugi
  • Patent number: 6208096
    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.
    Type: Grant
    Filed: January 25, 1999
    Date of Patent: March 27, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Peter Mahr, Klaus Oldermann
  • Patent number: 6201361
    Abstract: A mail piece handler defines a paper path having a downstream direction. A first motor is mechanically coupled with the mail piece handler, and an encoder is operatively coupled with the mail piece handler. A mail piece sensor is positioned at the paper path, and a print rotor is positioned at the paper path downstream of the mail piece sensor, the print rotor having a print surface. A second motor is mechanically coupled with the print rotor, and an electronic controller is communicatively coupled with the encoder, with the mail piece sensor, and with the second motor, the controller disposed in the event of sensing of a mail piece by the mail piece sensor to control said second motor so as to cause the print surface of the print rotor to move at substantially a speed measured via the encoder.
    Type: Grant
    Filed: August 5, 1999
    Date of Patent: March 13, 2001
    Assignee: Ascom Hasler Mailing Systems AG
    Inventor: Martin Müller
  • Patent number: 5896016
    Abstract: Ferries in particular may have identical drives at the bow and stern in order to avoid turning the ship when the direction of travel changes. Normally, when travelling, the rotation speed of the front screw is selected to be lower than the rotation speed of the rear screw. According to the invention, minimum-value regulation of the sum of the recorded real power levels of both drive systems is used for efficiency optimization. In the case of the associated arrangement, a regulator (10) is provided, with the real power levels of both drives as input variables, that rotation speed of the bow screw at which the sum of the real power levels is a minumum being determined in the regulator (10).
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: April 20, 1999
    Assignee: Siemens AG
    Inventor: Karl-Heinz Bayer
  • Patent number: 5814956
    Abstract: A method and apparatus for controlling a machine in a power failure. The present invention is applicable to such machines that a tool and a workpiece must always be controlled in synchronization with each other, and allows the tool and workpiece to stop without any damage in the power failure situation. If a power failure occurs during a synchronous cutting operation, the present invention disables a power regeneration function, connects a discharge resistor unit to a DC link of a power regeneration circuit, decelerates motors for tool drive and workpiece drive in synchronization with each other, and retracts the tool back to a safe area by driving a motor for tool feed with the power regenerated from the other two motors.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: September 29, 1998
    Assignee: Fanuc Ltd.
    Inventors: Shinichi Kono, Junichi Tezuka
  • Patent number: 5796221
    Abstract: A controller for detecting abnormal operating conditions of a continuous motion machine such as a packaging machine. The acceleration and velocity of motors for the various axes of the machine are examined by the controller and rapid deceleration or a more gradual deceleration to a lower velocity relative to a machine velocity are employed for stopping the machine when overloads in the form of jams or mechanical faults occur in moving parts of the machine. By using this system, machine overloads can be detected much earlier than by using conventional techniques, and as a result, damage resulting from overloads and nuisance tripping can be eliminated or greatly reduced.
    Type: Grant
    Filed: July 14, 1994
    Date of Patent: August 18, 1998
    Assignee: Paper Converting Machine Company
    Inventors: Charles C. Cramer, Dale M. Cherney
  • Patent number: 5757147
    Abstract: A method and apparatus for controlling a multiple motor drive arranged to drive printing cylinders of a printing machine sychronously decelerates each of the drives upon a failure or defect occurring in one or more of the components of the drive system such that the individual printing cylinders are decelerated in a manner synchronized with one another with respect to rotation angle. The apparatus includes a main control device which detects a failure in one of the drive system components and controls the drive units to decelerate the drive units to a standstill in accordance with a time function. The time function is determined by the rotation of the drive unit which contains the component that failed.
    Type: Grant
    Filed: June 7, 1996
    Date of Patent: May 26, 1998
    Assignee: Man Roland Druckmaschinen AG
    Inventors: Joachim Blumor, Albrecht Volz, Holger Wiese
  • Patent number: 5635807
    Abstract: A system (200) provides control of speeds and positioning of linear or rotary actuators (14A, 14B, 342A, 342B), and the system (200) may be used to control both speeds and steering of a conveyance (10). A transducer sensitivity control apparatus (202) provides selective control of sensitivity of transducers (28A, 28B) in an X-Y controller (26). The X-Y controller (26) delivers voltages to a steering sensitivity control apparatus (156, 180) that decreases, differences as an inverse and nonlinear function, in the two voltages supplied by the X-Y controller (26), thereby reducing steering sensitivity of the conveyance (10), increasing controllability in turns by decreasing sensitivity of joystick (34) movement, and/or automatically slowing the conveyance (10) when making sharp turns.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: June 3, 1997
    Inventor: John L. Lautzenhiser
  • Patent number: 5629567
    Abstract: A speed control system for an AC electric locomotive of the type having a plurality of wheel-axle sets with each wheel-axle set being coupled to an independently controllable AC electric traction motor and each motor having a corresponding speed sensor, each speed sensor providing a pair of signals which are resolvable to determine the speed and direction of rotation of the associated motor rotor, wherein the control system is arranged for maintaining torque control during failure of one of the signals from an associated speed sensor. The system detects the presence of each of the pair of signals from each speed sensor and responds to detection of only one of the pair of signals from one of the speed sensors for setting motor speed in response to the detected one of the signals. Direction is then determined by using signals from another of the speed sensors.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: May 13, 1997
    Assignee: General Electric Company
    Inventor: Ajith K. Kumar
  • Patent number: 5422550
    Abstract: A control system and method for a plurality of motors utilize one, and only one, motor drive unit that provides power to drive any one of the motors. The system and method also utilize a controller that controls which of the motors to energize. Power from the motor drive unit can be communicated to one of the motors selected by the controller, or power from a primary power source can be communicated to one or more of the motors selected by the controller. Sequencing of the motors to and from the motor drive unit and the primary power source, and between the two, is automatically controlled, such as based on how long each of the motors has been used. Accordingly, a method of controlling a plurality of motors comprises: defining a motor utilization criterion; sensing a parameter affected by the number of the motors that are operating; and sequentially starting and cumulatively operating ones of the motors selected in response to the motor utilization criterion and the sensed parameter.
    Type: Grant
    Filed: May 27, 1993
    Date of Patent: June 6, 1995
    Assignee: Southwest Electric Company
    Inventors: Michael L. McClanahan, Charles E. Ogden
  • Patent number: 5359154
    Abstract: An inverter controlled conveying/measuring apparatus according to the invention includes a conveyor (3) for conveying an object (W) of measurement. The conveyor (3) is driven by an AC motor (M2). Inverter (20) controls and operates the conveyor (3) at a given speed by supplying the AC motor (M2) with frequency converting signals according to a specified frequency. A measuring section (4) is arranged on a conveying path of the conveyor (3) in order to measure an attribute of the object (W) being conveyed by the conveyor (3).
    Type: Grant
    Filed: January 7, 1993
    Date of Patent: October 25, 1994
    Assignee: Anritsu Corporation
    Inventors: Fumihiro Tsukasa, Hideya Fujimoto, Kazuhiko Horikoshi, Osamu Tanaka, Kunio Kikuchi
  • Patent number: 5278477
    Abstract: A drive system for a printing machine with a plurality of printing units connected to one another via a gear train into which power is fed at different points by at least two motors, includes supplying each of the motors via a respective controllable, line-commutated converter. A signal is generated by each of the converters that is limited in time between two firing pulses. A current setpoint value is transferred only within a time span in which all of the converters have activated the signal. Coverage of all of the signals which are limited in time is assured in all operating states.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: January 11, 1994
    Assignee: Heidelberger Druckmaschinen AG
    Inventors: Klaus Hartmann, Michael Kruger, Georg Rossler
  • Patent number: 5266787
    Abstract: A dual motor speed control circuit for providing independent speed control of two motors in a laser scanning device is disclosed herein. This apparatus utilizes a single input signal having variable frequency and duty cycle components. The speed of the first motor is controlled by utilizing the frequency component of said input signal while the speed of the second motor is controlled by utilizing the frequency and duty cycle components of said input signal. Specifically, a DC signal is generated that is dependent upon the duty cycle component of said input signal and said DC signal is utilized to offset the speed of the second motor from the speed value as determined by the frequency component of said input signal.
    Type: Grant
    Filed: January 11, 1991
    Date of Patent: November 30, 1993
    Assignee: Symbol Technologies, Inc.
    Inventors: Thomas Mazz, Anthony Fama, Frederick Helm
  • Patent number: 5237251
    Abstract: A control unit enables tapping onto an end surface of a workpiece while rotating the workpiece. A workpiece rotational speed command (Vc) is applied from an NC unit (90) to first and second speed control circuits (111, 121) of first and second control circuits (110, 120), to operate these control circuits in a speed control mode, so that the workpiece (70) and a tapper (80) respectively mounted on first and second main spindles (10, 20) are caused to rotate at the same speed by first and second main spindle motors (11, 21).
    Type: Grant
    Filed: February 4, 1992
    Date of Patent: August 17, 1993
    Assignee: Franc Ltd.
    Inventors: Shinichi Kono, Hironobu Takahashi
  • Patent number: 5203762
    Abstract: A decanter centrifuge includes a control system for receiving input AC power and outputting a variable voltage and frequency for controlling the speed of the backdrive and the main drive motor. The control system includes a first controller for converting AC power into DC power and then converting the DC power to AC power at a variable voltage and frequency to the main drive motor. A second controller is connected to the first conversion unit through a common DC bus. The second controller converts DC power to AC power and supplies AC power at a variable frequency to the backdrive motor. The braking force created by the backdrive motor during operation of the decanter centrifuge creates electricity which is passed through the second controller and through the common DC bus to the first controller. Thus, the generated power from the backdrive motor is converted into power for use by the main drive motor.
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: April 20, 1993
    Assignee: Alfa-Laval Separation, Inc.
    Inventor: Joseph L. Cooperstein
  • Patent number: 5093972
    Abstract: A control unit capable of driving a compound lathe so that an end face of a rotating workpiece can be tapped. The control unit (100) comprises first and second control circuits (110, 120) for controlling the rotation of first and second spindles (10, 20) respectively fitted with the workpiece (60) and a tapper (70). At start of tapping operation, the second control circuit executes position loop control in accordance with a deviation (.epsilon.) between position feedback signals (PCC1, PCC2) related to the two spindles, thereby equalizing rotational speeds of the two spindles, and then causes the second spindle to rotate at a speed higher than that of the first spindle by a tapping speed in accordance with the deviation (.epsilon.
    Type: Grant
    Filed: January 2, 1991
    Date of Patent: March 10, 1992
    Assignee: Fanuc Ltd
    Inventors: Masahiro Kaku, Shinichi Kono, Masaaki Fukukura
  • Patent number: 4939431
    Abstract: In a control system for synchronous rotation of the cutter heads in a multi-cutter shield machine, the rotation cutter heads are so disposed in generally the same plane such that the distance between the centers of the adjoining cutter heads is larger than the radius, and smaller than the diameter, of the cutter heads. The rotating cutter heads are driven independently of each other by electric drive systems, respectively. Each of the electric drive systems consists of plural motors with a reduction gear, coupled to the respective rotating cutter heads by means of a pinion and gear. The motor rotation is so controlled and the cutter heads are so synchronously rotated, that the angle of deviation between the cutter heads is within such an allowable range that the cutter heads will not interfere with each other even if there is any imbalance in excavating and rotating resistances between the cutter heads.
    Type: Grant
    Filed: July 21, 1989
    Date of Patent: July 3, 1990
    Assignees: Ishikawajima-Harima Kukogyo K.K., Hitachi Construction Machinery Co., Ltd., Ohbayashi Corp., Taisei Corp., Daiho Construction Co., Ltd.
    Inventors: Hidetsugu Yamazaki, Ryuzaburo Otsuka, Takashi Moro, Toshihumi Yuzawa, Seiji Tadano, Kiyoshi Tsuchiya
  • Patent number: 4912377
    Abstract: A technique for driving with continuous synchronized movement a plurality of parallel pulling cables of a transportation installation in a direction parallel to the cables comprising at least one vehicle connected in line to the cables. Each cable is driven by a separate independent drive device powered by a dedicated power source. Drive forces in each drive device are monitored and used to control the drive device speed of at least one drive device so as to maintain equal cable speeds.
    Type: Grant
    Filed: May 24, 1988
    Date of Patent: March 27, 1990
    Assignee: Pomagalski, S.A.
    Inventor: Jean-Jacques Bertrand
  • Patent number: 4881019
    Abstract: A wiper control system includes a rear wiper control circuit associated with a front wiper control circuit. The wiper drive signals generated in the front wiper control circuit are fed to the rear wiper control circuit. The rear wiper control circuit derives a rear wiper drive timing on the basis of the occurrences of the front wiper drive signals. The rear wiper driving frequency is generally lower than that of the front wiper driving frequency. The lower rate of the rear wiper driving frequency relative to the front wiper driving frequency is preferably variable depending upon the vehicle driving condition.
    Type: Grant
    Filed: April 29, 1987
    Date of Patent: November 14, 1989
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yasuhiro Shiraishi, Yoshinori Nagamine
  • Patent number: 4812725
    Abstract: A linear motor system includes first and second linear motors driving a load along spaced-apart supports. A positioning table, or a portion of a machine tool, supported between the first and second linear motors includes a device for varying the position of the table or portion along an axis extending between the first and second linear motors. A single motor control system produces a motor drive signal. A proportioning device proportions the portion of the motor drive signal fed to the two motors in a proportion controlled by the position of the table or portion.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: March 14, 1989
    Inventor: Anwar Chitayat
  • Patent number: 4789814
    Abstract: A transport speed control system for a glass ribbon annealing installation comprising means to control a peripheral drive speed of those of glass ribbon transporting rollers which contact a portion of the glass ribbon at positions downstream of at least a substantially mid-position of the glass ribbon with respect to a direction of transport, to be higher than an advancing speed of that portion of the glass ribbon.
    Type: Grant
    Filed: July 7, 1987
    Date of Patent: December 6, 1988
    Assignee: Nippon Sheet Glass Co., Ltd.
    Inventors: Naotomo Akashi, Takeshi Yokokawa, Katsuaki Ninomiya, Harumi Shima, Takeshi Horiguchi
  • Patent number: 4706570
    Abstract: A crane with an anti-skewing device comprising a platform suspended under a bridge deck by two end truck assemblies supported by runways on a bridge. Each end truck assembly includes two sets of trolleys and an upper load bar interconnects the two sets of trolleys. A lower load bar is suspended from the upper load bar by a kingpin for rotation about a vertical axis. Hinge tubes support the platform on the suspension assembly for pivotal movement in a direction lengthwise of the platform. Each end truck assembly is driven by a variable speed motor. As skewing occurs a mechanical sensing mechanism senses relative movement between lower load bar and the upper load bar and provides a signal to an electronic circuit causing one or both of the motors associated with the end truck assembly on which the sensing mechanism is mounted to increase or decrease the speed of the motor and thereby correct the skew.
    Type: Grant
    Filed: July 17, 1985
    Date of Patent: November 17, 1987
    Assignee: Acco Babcock Inc.
    Inventors: Dominik J. Moro, Robert R. Reisinger, James M. Larson, Roscoe E. Kuhn
  • Patent number: 4667136
    Abstract: An improved drive circuit for steering a motorized wheelchair. A control mechanism produces right and left drive signals to respective right and left wheel drive motors. These right and left drive signals are amplified by right and left amplifiers to provide the necessary magnitude power signal to the motors. The input to the amplifiers are cross-coupled so that each amplifier will amplify its own input signal plus a portion of the cross-coupled input signal.
    Type: Grant
    Filed: April 4, 1986
    Date of Patent: May 19, 1987
    Assignee: Gordon W. Rosenberg
    Inventor: John Bell
  • Patent number: 4567413
    Abstract: A method and device for controlling a power steering apparatus for performing power steering by controlling a rotational speed of a motor-driven oil pump, wherein an alarm signal is generated when the power steering apparatus is overloaded, and a current is not supplied to a motor for a predetermined period of time when the power steering apparatus is overloaded.
    Type: Grant
    Filed: June 12, 1984
    Date of Patent: January 28, 1986
    Assignee: Jidosha Kiki Co., Ltd.
    Inventors: Hideo Yabe, Ichiro Koike
  • Patent number: 4518899
    Abstract: In textile machinery wherein two or more loads--such as transport rollers of a tension frame and a bank of spindles carrying take-up spools--are driven by respective three-phase motors of the asynchronous (induction) type at speeds which are different from each other but are to be mutually correlated during an entire operating cycle including a startup and a cutoff period, the motor with the shorter acceleration time is slowed down during startup to let it reach its operating speed substantially at the same time as the other motor whereas the motor with the longer deceleration time is braked during cutoff in order to reach standstill substantially simultaneously with the other motor. The slowdown during startup and the braking during cutoff can be controlled by a comparator which determines deviations of the speed ratio of the two motors from a predetermined reference value.
    Type: Grant
    Filed: March 14, 1984
    Date of Patent: May 21, 1985
    Assignee: Zinser Textilmaschinen GmbH
    Inventor: Horst Wolf
  • Patent number: 4500818
    Abstract: The invention disclosed is a control system for controlling a pair of separately excited motors arranged such that each motor of the pair drives a separate wheel on a common axle of an electrically powered vehicle. The control system continuously and individually adjusts the field excitation of the drive motors so that torque and speed of the separate wheels are apportioned to the wheels as a function of the steering angle of the vehicle.
    Type: Grant
    Filed: December 22, 1983
    Date of Patent: February 19, 1985
    Assignee: General Electric Company
    Inventors: Charles E. Konrad, Ronald E. Gareis, Amratlal C. Lodhia
  • Patent number: 4377777
    Abstract: Two DC motors are driven by switching pulse drive circuits, and the switching on times of drive pulses are made to be out of phase with each other at the two switching pulse drive circuits. One of the two DC motors rotates rotary video heads, and the other drives a capstan of a video tape recording and/or reproducing apparatus. The drive pulses are preferably synchronized with horizontal synchronizing pulses of a video signal to be handled by the video tape recording and/or reproducing apparatus in order to avoid pulse noises.
    Type: Grant
    Filed: August 15, 1980
    Date of Patent: March 22, 1983
    Assignee: Sony Corporation
    Inventors: Osamu Asagi, Masaaki Sakai
  • Patent number: 4369397
    Abstract: A control arrangement for manually controlling speed and direction of devices such as electric motors typically where these drive the two driving wheels of a wheel chair, the control being achieved by having the radiant energy falling on several detectors, these being responsive to radiant energy falling on them from an emitter and this being controlled by the position of a reflective surface which is coupled to a control arm, the outputs from each detector being compared electronically both to determine whether the motor or motors should drive in a forward or rearward direction and their speed.
    Type: Grant
    Filed: July 25, 1979
    Date of Patent: January 18, 1983
    Inventor: Graham L. Read
  • Patent number: 4350219
    Abstract: The battery energized electric motor vehicle has a main driving motor connected to the battery via a footpedal operated control circuit; an auxiliary electric motor for a steering device is connected to the battery in series with the main driving motor and across the control circuit of the latter so that a difference voltage between the battery voltage and the instant driving voltage applied to the main driving motor controls the steering device.
    Type: Grant
    Filed: December 5, 1980
    Date of Patent: September 21, 1982
    Assignee: Robert Bosch GmbH
    Inventors: Gottfried Olbrich, Peter Pfeffer
  • Patent number: 4334175
    Abstract: In a speed control method for digitally controlling the speeds of motors in a sectional drive system including the steps of setting a speed difference of each section with respect to a line speed reference, the speed difference set value is varied by pressing a push button switch and varying the speed difference set value by a unit value every unit operation time when the button switch is pressed.
    Type: Grant
    Filed: June 29, 1979
    Date of Patent: June 8, 1982
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Hiroichiro Tanaka, Yasuo Nagatani
  • Patent number: 4318197
    Abstract: Conveyance loading ramp has its inner end pivotally supported adjacent a building structure and the other end mounted on a mobile undercarriage having a pair of ground engaging wheels mounted one on each side of the ramp for rotation about a common horizontal axis. The undercarriage is supported for pivotal movement about a vertical axis for steering and an improved hydraulic driving and steering system includes separate hydraulic motor connected in series to drive the wheels.
    Type: Grant
    Filed: November 21, 1979
    Date of Patent: March 9, 1982
    Assignee: Wollard Aircraft Equipment, Inc.
    Inventor: Otto Drozd
  • Patent number: 4247108
    Abstract: A toy vehicle game includes an endless track defining two generally parallel lanes along which toy vehicles including reversible rotary drive motors responsive to current polarity reversal are driven while being biased against one or the other of the side walls of the track depending upon the polarity of current supplied to the vehicle motor. Current is supplied to the track through contact strips and a control system which permits the operators to separately and independently control current to the contact strips. When the polarity of the current to one of the toy vehicles is reversed a boost in available average electrical power is made available to that toy vehicle for a first limited duration maximum period. After using the boosted average power the selected toy vehicle must return to its original lane to be operated there at a normal power level for a mimimum of a second limited fixed duration period before power boost is again available.
    Type: Grant
    Filed: September 10, 1979
    Date of Patent: January 27, 1981
    Assignee: Ideal Toy Corporation
    Inventors: Neil Tilbor, William Rosenhagen
  • Patent number: 4196785
    Abstract: An electronic differential speed control circuit for driving the inboard and outboard A.C. wheel motors at different relative speeds depending upon the steering angle during a turn. An electrical circuit for sensing the torque of the tractor's wheel motors to maintain a constant implement draft. A hollow tubular axle pivots around the tractor's longitudinal material-transferring tunnel to conserve space and permit mounting of the wheel motors within the axle. The tunnel has two material-transferring compartments or passageways, and has vertically movable extensions on either end to facilitate coupling to accessories. An electrical power outlet is provided for energizing non-motor driven accessories.
    Type: Grant
    Filed: September 11, 1978
    Date of Patent: April 8, 1980
    Inventor: James H. Downing, Jr.
  • Patent number: 4163927
    Abstract: A circuit for controlling the speed of a feed roller in a card or the like in which the sliver thickness is detected and a signal produced which is combined with signals representing feed and doff roller speeds, and a signal representing feed motor torque. The resulting signal is compared with a ramp signal to drive the feed motor so as to maintain sliver thickness at a desired value.
    Type: Grant
    Filed: May 4, 1977
    Date of Patent: August 7, 1979
    Assignee: Fiber Controls Corporation
    Inventor: Karl R. Grice, Jr.
  • Patent number: 4015177
    Abstract: A tape recorder has two tape spools independently driven by two reversible electric motors. The tape passing from one spool to the other drives a tachometer wheel which provides a tape speed signal. This signal is compared with a reference value by a differential amplifier which provides control signals for differentially controlling the speeds of the motors to maintain the tape at a constant speed.
    Type: Grant
    Filed: February 15, 1974
    Date of Patent: March 29, 1977
    Inventor: Filinto Vaz Martins