With "feed-rate" Control Patents (Class 318/571)
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Patent number: 4322669Abstract: An apparatus for controlling a DC motor driven screw feed which moves the table of a machine tool into prescribed positions including a plurality of limit switches which detect the position of the table, a rate change control circuit which receives signals from the limit switches and changes the rate of revolution of the DC motor when the table has reached prescribed rate change positions and a current limiting circuit which supplies the DC motor with a prescribed constant current and keeps the output torque of the DC motor at a prescribed level when the table has reached a prescribed dwell position.Type: GrantFiled: July 5, 1979Date of Patent: March 30, 1982Assignees: Toyota Jidosha Kogyo Kabushiki Kaisha, Yaskawa Electric Mfg. Co. Ltd.Inventors: Nobuo Fukuma, Yoshito Kato, Takao Terui
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Patent number: 4321516Abstract: A spindle of a machine tool driven by an induction motor is controlled by a torque control system including a pulse generator coupled to the spindle, a reversible counter which counts the number of pulses, a first register connected to receive an output signal of the counter via sampling gate. The data in the first register is transferred to a second register and difference between data in the first and second registers is calculated by a calculator in the form of a register. An input device delivers a speed instruction signal and an angular position instruction signal which is added to an output signal of the first register to form a position instruction signal. A computation unit is provided to calculate respective phase currents of the induction motor in response to the speed instruction signal or the position error signal for continuously controlling motor torque or position the spindle at an instructed angular position.Type: GrantFiled: July 11, 1980Date of Patent: March 23, 1982Assignee: Toshiba Kikai Kabushiki KaishaInventor: Tsutomu Ohtsuka
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Patent number: 4315200Abstract: A frequency-voltage converting system has a first sampler for sampling the input signal at a predetermined time interval a second sampler for sampling the input signal after elapse of a predetermined time period from said predetermined sampling time, and comparator for comparing the sampled values obtained respectively from said first and second samplers and providing the difference of said sampled values as a value proportional to the frequency of said input signal.Type: GrantFiled: August 27, 1979Date of Patent: February 9, 1982Assignee: Canon Kabushiki KaishaInventors: Yasuaki Yamada, Toshiaki Ozawa, Hiroatsu Kondo
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Patent number: 4305028Abstract: A system for evaluating whether a work-performing robot can perform a series of programmed motions is disclosed which includes means for continuously comparing the velocity of the various links of a robot simulator, which is manually moved through the sequence of motions to be programmed, against predetermined velocity limits associated with the corresponding links of the work-performing robot which will reproduce the programmed steps, and providing humanly perceptible alarm indications uniquely identifiable with the various robot links when the motions manually programmed on the robot simulator exceed the velocity limits of the work-performing robot. Additionally, the individual velocities of the various robot simulator links are summed, and the sum continuously compared against the power limit of the hydraulic pump driving the link actuators of the work-performing robot.Type: GrantFiled: April 4, 1980Date of Patent: December 8, 1981Assignee: Nordson CorporationInventors: Evans Kostas, Gerald W. Crum, Jerome F. Walker
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Patent number: 4297734Abstract: A sampled data servo positioning system employs an actuator to move a member between a current and a target position. Incremental position feedback is provided only at sampling times. The system employs a model responsive to a velocity related input signal to produce a continually available model incremental position signal. Phase comparing means indicates phase differences between the model and sampled position signals at the sampling times.The system has two operational configurations in the first of which a source of saturation control signals is connected to the actuator to cause maximum acceleration or deceleration thereof. In this first configuration, the model is forced to track the actuator motion by means of feedforward plus feedback control. The feedforward signal represents actuator performance while the feedback signal is the position signal phase difference.Type: GrantFiled: December 26, 1979Date of Patent: October 27, 1981Assignee: International Business Machines CorporationInventors: William J. Laishley, John R. Taylor
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Patent number: 4291262Abstract: While a motor shaft (13) is moving from a previous position to a present command position, the number of steps between the present command position and a new command position is calculated. After the shaft (13) reaches the present command position, the shaft (13) is driven to the new command position in accordance with the calculated number of steps.Type: GrantFiled: October 29, 1979Date of Patent: September 22, 1981Assignee: Ricoh Company, Ltd.Inventor: Yoshinori Nakajima
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Patent number: 4287461Abstract: A motor driving system which is particularly useful for driving scanning carriages in a continuously variable reducing electrophotographic copier. The motor driving system produces one of a number of different controlled and repeatable position acceleration and velocity profiles of the scanning carriage with respect to motion of the copier drum; a different position acceleration and velocity profile is produced for each reduction mode in a substantially continuous range of reduction modes. The motor driving arrangement includes a single control loop for driving a servo motor which provides the drive for the scanning carriage. A driving signal source produces a driving signal pulse train, each pulse representing a desired increment of motor travel, and a direction signal representative of the desired direction of travekl.Type: GrantFiled: December 6, 1979Date of Patent: September 1, 1981Assignee: International Business Machines CorporationInventors: George G. Promis, Gerald L. Smith, John C. Wilson
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Patent number: 4287462Abstract: A control system for a veneer lathe feeds a knife into a rotating log to peel off a continuous sheet of veneer. When the knife is retracted, the orientation of the log is established and stored so that when the peeling operation is resumed, the knife motion is calculated to engage the log at the discontinuity in the log surface produced during retraction. In addition, when the knife engages the rotating log a compensation factor is momentarily added to the knife motion feed command to alleviate variations in veneer thickness caused by the mechanics of the lathe during impact. A considerable savings of veneer is obtained.Type: GrantFiled: May 13, 1980Date of Patent: September 1, 1981Assignee: Unico, Inc.Inventors: Thomas L. Beck, Rick L. Tennessen
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Patent number: 4287460Abstract: The time for positioning of a machine under numerical control is determined so that the positioning is finished at the moment when the amplitude of vibration of the machine is reduced to zero. In the thus predetermined time at least accelerating control and decelerating control are conducted to achieve control for positioning the machine at a commanded position.Type: GrantFiled: March 13, 1979Date of Patent: September 1, 1981Assignee: Fujitsu Fanuc LimitedInventors: Ryoichiro Nozawa, Yoichi Amemiya, Mitsuo Kawamata, Shigeru Isohata, Takao Sasaki, Yoshitaka Takekoshi
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Patent number: 4279013Abstract: The controller includes a power sensing device which monitors the instantaneous power drawn by the machine and compares it with a predetermined limit level of desired power consumption. A user programmable timer is manually accessible for loading a selected time delay period therein. The controller provides an output capable of altering the machine operation when the machine power consumption has continuously exceeded the limit value for the selected time period. The controller outputs may be latched or nonlatched once an overlimit condition is detected in accordance with a user selectable programmed parameter. In an adaptive mode, the controller forces the feed rate to a programmable feed rate for a selected period of time upon initial impact between the workpiece and the machine tool.Type: GrantFiled: October 31, 1979Date of Patent: July 14, 1981Assignee: The Valeron CorporationInventors: Larry E. Cameron, Kenneth J. Cook, Vance E. Neff, Keith L. Rowland
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Patent number: 4273482Abstract: An automatic machine for displacing a shaping tool, such as a router, over a work area includes a tool mounting assembly carried by support means such as an articulated arm. The arm is movable by first movement means relative to fixed structure of the machine over the whole work area, while the tool mounting assembly can be moved within a limited zone relative to the arm by second movement means. The movement of the tool mounting assembly (and thus of the tool) is directly measured relative to the machine fixed structure and compared with a required movement to generate an error signal. This signal is fed to the second movement means which endeavors to move the tool mounting assembly as required over the work area.Type: GrantFiled: June 27, 1979Date of Patent: June 16, 1981Assignee: Conti-Form Machine Tools LimitedInventors: William M. LLoyd, Brian M. Lloyd
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Patent number: 4266375Abstract: A feed control apparatus wherein a servomotor control device responsive to feed pulses distributed from a numerical controller controls a d.c. servomotor to advance a grinding wheel carriage of a grinding machine through the rotation of a feed screw successsively at a speed-up feed rate, a rapid feed rate, a slow-down feed rate and a grinding feed rate. A detection device is provided, which outputs a velocity checking signal to an abnormality confirmation device when the carriage reaches a velocity checking point defined within a slow-down feed range. When confirming that the feed rate of the carriage has exceeded a reference feed rate lower than the rapid feed rate, the abnormality confirmation device applies a stop signal to an emergency stop control circuit in response to the velocity checking signal, so that the rotation of the servomotor is immediately discontinued.Type: GrantFiled: March 7, 1980Date of Patent: May 12, 1981Assignee: Toyoda-Koki Kabushiki-KaishaInventors: Hideo Nishimura, Yasufumi Tokura, Kunihiko Unno, Minoru Enomoto, Isamu Yokoe, Norihiko Shimizu, Haruo Ohmura
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Patent number: 4267495Abstract: To initiate a scheduled speed change at the correct point in the operating cycle of a machine, a speed change command is subjected to a variable delay. Attaining the commanded speed level too early or too late in one cycle results in the speed change command being correspondingly delayed or advanced in the next cycle. In the preferred embodiment, a low point controller is designed to control the high-to-low speed transition in a multiple spindle bar or screw machine to achieve "feed" speed at the optimum point to decrease cycle time while avoiding damage to the cutting tools.Type: GrantFiled: October 5, 1979Date of Patent: May 12, 1981Assignee: Cone-Blanchard Machine CompanyInventor: Bernard W. Wilterdink
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Patent number: 4266172Abstract: In a tracer control system in which tracer head control is switched over from a quick feed mode to a deceleration mode of operation to alleviate a shock when the stylus of the tracer head contacts the model, the amount of change in the configuration of the model at a profiling start point is detected to control the point of switching over the quick feed mode to the deceleration mode of operation for the next profiling start point in accordance with the detected value, thereby to ensure that the above mentioned mode switching is always accomplished at substantially a constant position relative to the profiling start point on the model surface so as to shorten the profiling time.Type: GrantFiled: April 23, 1979Date of Patent: May 5, 1981Assignee: Fujitsu Fanuc LimitedInventor: Etuo Yamazaki
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Patent number: 4266171Abstract: A drilling apparatus includes a drilling rod, a feed motor for advancing and retreating the rod in relation to an object to be drilled, and a control system for controlling the movement of the rod. The control system includes a pulse generator for producing one long duration pulse upon completion of each rotation of the drilling rod, an oscillator for producing high frequency pulses, a counter for counting the number of high frequency pulses during the long duration pulse, and a control circuit for controlling the feed motor in response to the counted number of pulses, the control system operating so that the counted number of high frequency pulses equals a predetermined number during the period of the long duration pulse.The control system is arranged to increase the advancing force of the drilling rod when its rotational speed increases (i.e.Type: GrantFiled: April 3, 1979Date of Patent: May 5, 1981Assignee: Toyo Kogyo Co., Ltd.Inventor: Tohru Mashimo
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Patent number: 4262454Abstract: A workpiece rotational speed controller having a pulse counter responsive to a pulse signal generated from a pulse generator for indicating the actual angular position of a cam shaft during grinding on a cam grinding machine and a comparator for comparing a count value of the counter with any one of set values which are set in a plurality of digital switches to designate respective speed change positions. A region detection counter is further provided, which counts any coincidence signal from the comparator so as to enable a command voltage generator to apply to a servomotor for cam shaft drive a command voltage that changes step by step in correspondence to the region detection counter output. This counter output is also applied to a gate circuit, which is thus enabled to selectively apply the set values of the digital switches to the comparator.Type: GrantFiled: June 1, 1979Date of Patent: April 21, 1981Assignee: Toyoda-Koki Kabushiki-KaishaInventors: Wataru Iida, Toshio Tsujiuchi, Shintaro Ishikawa
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Patent number: 4260940Abstract: A programmable automatic assembly system is provided which may be employed to assemble small parts. Each assembly station includes cooperating manipulator arms which are programmable to assemble parts on a centrally located work table. Improved facilities are provided for teaching the manipulator arms at each station, these facilities including a computer which assists the teaching operator in setting up the programs required for assembly of small parts to close tolerances. Each manipulator arm includes closed loop teach facilities for maintaining the arm at a previously located position during the teaching mode of operation. The computer is employed as a teach assist facility in performing a number of tasks during the teaching operation which are extremely difficult for the operator to perform manually. All of the assembly stations may be controlled during playback from a common disc storage facility so that the control circuitry and memory storage facilities at each manipulator are minimized.Type: GrantFiled: April 18, 1979Date of Patent: April 7, 1981Assignee: Unimation, Inc.Inventors: Joseph F. Engelberger, Torsten H. Lindbom, Maurice J. Dunne, William Perzley, Wilbur N. Roberts, Horace L. Gardner
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Patent number: 4257000Abstract: An apparatus for controlling the length of movement of a controlled member along a path of repeated operating positions. The apparatus comprises a function generator with an axis digital integrator for each axis of movement of the controlled member and a resultant length of movement digital integrator. All digital integrators have the same input iterate rate. By initially setting the integrand of the resultant length of movement integrator to the square root of the sum of the squares of the initial integrand values of the axis digital integrators of the function generator, the output of the resultant length of movement digital integrator is proportional to the resultant of the distances commanded along the axes by the axis integrators of the function generator. A counter is set to the incremental distance between repeated operating positions and is counted down by the output of the resultant length of movement digital integrator.Type: GrantFiled: May 1, 1979Date of Patent: March 17, 1981Assignee: General Electric CompanyInventor: Richard L. Friberg
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Patent number: 4249113Abstract: A processing system for delinting cotton has a delinter driven by an AC drive motor. The delinter is fed by a feeder/cleaner driven by a DC feed motor. A visual display ammeter measures the current drawn by the drive motor and produces a given load voltage corresponding to the measured current. The load voltage is then translated into a feed voltage to the feed motor, thereby regulating the feed into the delinter at a predetermined rate responsive to the load on the drive motor.Type: GrantFiled: July 25, 1977Date of Patent: February 3, 1981Assignee: Brandon and Clark Electric Company, Inc.Inventor: John W. Werner
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Patent number: 4237408Abstract: A method and apparatus are disclosed for controlling a machine tool as a function of the torque load on a cutting tool. The apparatus detects the spindle motor current which may vary over four decades, the spindle motor voltage which may vary over two decades and the cutting tool angular velocity which may vary over three decades. The decimal values of the detected variables are converted to corresponding logarithmic values and stored in digital form. A microprocessor utilizes the stored values to calculate the value of torque on the cutting tool which may vary over five decades. A microprocessor determines the idle torque by averaging the torque which is measured several times over one spindle revolution. The idle torque is subtracted from subsequent gross torque measurements to provide an indication of actual cutting load on the tool. The operation of the machine is modified in response to the actual torque exceeding a predetermined reference torque value.Type: GrantFiled: August 10, 1979Date of Patent: December 2, 1980Assignee: Cincinnati Milacron Inc.Inventor: Thomas R. Frecka
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Patent number: 4234830Abstract: Disclosed is a stepping motor control utilizing a microprocessor. The control is suitable for driving one or more stepping motors one at a time or in unison. In the illustrated embodiment when plural motors are driven together they are driven at the same rate or at rates in a fixed proportion to one another although several of the features of the invention are suitable for use in circuits providing contouring control; i.e., where separate motors are driven at separate stepping rates proportional to the relative distances each is to traverse for a single movement. An acceleration/deceleration circuit is utilized which provides simple yet highly accurate and efficient control of the stepping motors. Feed rate compensation for simultaneous drive of two motors is provided. Also a means is provided to allow stepping rates in excess of the counting rate capability of the microprocessor.Type: GrantFiled: January 25, 1978Date of Patent: November 18, 1980Assignee: Dana CorporationInventor: Lee E. Cannon
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Patent number: 4226546Abstract: The intermittent movement of the printer's carriage and "daisy"-type print wheel is controlled by a relatively simple, reliable digital control system. The difference between the desired velocity and the actual velocity of each member is measured digitally. This difference constitutes an error signal which is used to retrieve stored values of acceleration or deceleration corresponding to various values of the error signal. These values are used to develop a corresponding electrical signal which is used to accelerate or decelerate the member to reach the desired velocity. A relatively simple circuit is provided for reliably returning the carriage or print wheel to a desired position after overshooting the position, despite a relatively large amount of overshoot. Simple, low-power-consumption holding or drive circuits utilizing pulsed voltages are provided for the stepping motors used for ribbon feed and line feed, and for the solenoids used for ribbon shift, print wheel shift and print hammer energization.Type: GrantFiled: December 6, 1978Date of Patent: October 7, 1980Assignee: SCI Systems, Inc.Inventor: Mark H. Hoffman
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Patent number: 4227134Abstract: A machine tool such as a multiple spindle automatic machine tool is provided with a motor acting through a slippable clutch on each of the multiple spindles to rotate the spindles and each spindle is provided with a brake to brake each spingle to a stop. A spindle rotational means is provided to rotate the spindle at a speed less than that established by full engagement of the clutch. This is accomplished by partial engagement of each the clutch and brake so that each slips. A spindle positioning means is further provided to position the spindle at a desired arcuate position. At such time the clutch is disengaged and the spindle is locked in rotational position. The clutch and brake are differentially controlled to control the relative average torque transmission therethrough to maintain a desired slow speed.Type: GrantFiled: January 5, 1979Date of Patent: October 7, 1980Assignee: Acme-Cleveland CorporationInventor: Lambert Haner
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Patent number: 4224561Abstract: An improved regulator is provided for varying the rotational speed of a screw conveyor arranged to supply material to a variable-volume chamber having a piston slidably mounted in a cylinder. The regulator produces a sum signal proportional to the algebraic sum of positive input signals reflecting the desired degree of chamber filling and the desired discharge volume, and negative input signals reflecting the actual filling volume and the actual degree of chamber filling. This sum signal is converted to a proportional time-dependent signal which is used to adjust the speed of the conveyor. The conveyor speed is increased or decreased by an amount depending on the magnitude and polarity of the sum signal. In use, the regulator practices an improved method of regulating the speed of a conveyor.Type: GrantFiled: March 16, 1979Date of Patent: September 23, 1980Assignee: Moog GmbHInventor: Herbert Handte
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Patent number: 4224670Abstract: A tracer control system in which data defining a tracing operation is inputted from an input device and stored in a memory, and the stored data is read out by a processor to control the tracing path of a tracer head. Tracer machining is achieved in accordance with a displacement signal derived from a tracer head which traces the surface of a model.Type: GrantFiled: October 20, 1978Date of Patent: September 23, 1980Assignee: Fujitsu Fanuc LimitedInventor: Etuo Yamazaki
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Patent number: 4214192Abstract: In path control apparatus for a numerically controlled machine tool, a computer determines the trajectory to be traversed in space, resolves the latter by way of interpolation into the axial increments of the individual feed axes and performs complete position control for each axis. The interpolation is accomplished by the method of direct function computation, using travel distance increments proportional to the trajectory velocity. The position control is designed as a discrete control and operates with the premise that the minimum total computing cycle time is shorter than the sampling time of the fastest position control loop required by the control system.Type: GrantFiled: December 20, 1977Date of Patent: July 22, 1980Assignee: Siemens AktiengesellschaftInventors: Gunter Bromer, Horst Gose, Klaus-Rudiger Hoffmann, Christian Seeliger
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Patent number: 4208718Abstract: The feed rate of a computer controlled machine tool is periodically calculated every 9.6 milliseconds to produce a horsepower equal to a target horsepower at the cutting tool during a milling operation. When the feed rate rises above a predetermined level, the target horsepower is progressively lowered, and when the feed rate drops below a predetermined level, the target horsepower is progressively raised. The total amount of cutting time for each tool is measured and the amount of cutting time under increased target horsepower is also measured. When the amount of cutting time under increased target horsepower exceeds a predetermined percentage of the total cutting time for any given tool, a DULL TOOl signal is generated and the designated tool is subsequently replaced. If no cutting time is recorded, a BROKEN TOOL signal is generated and the broken tool is replaced.Type: GrantFiled: June 5, 1978Date of Patent: June 17, 1980Assignee: Kearney & Trecker CorporationInventor: Han-Chang Chung
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Patent number: 4206392Abstract: In a spindle control system in which a pulse coder is coupled with a spindle; a pulse train signal, derived from the pulse coder upon each rotation of the spindle through a predetermined rotational angle, is converted into an analog signal corresponding to the actual rotational speed of the spindle; and the analog signal is compared with a commanded speed signal to drive the spindle at the commanded speed. Upon application of a command for stopping the spindle at a predetermined position, a predetermined numerical value is set in an error register in accordance with a specified position signal from the pulse coder, the pulse train signal from the pulse coder is fed back to the error register, and the rotational position of the spindle is controlled with a signal corresponding to the content of the error register.Type: GrantFiled: April 21, 1978Date of Patent: June 3, 1980Assignee: Fujitsu Fanuc LimitedInventors: Tokiji Shimajiri, Kiyoshi Hattori
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Patent number: 4203062Abstract: The invention relates to an attachment for the machining by stock removal of parts to be turned, particularly such which have surface longitudinal profiles which differ from the exact circular shape and may furthermore be irregular, with the aid of a tool whose in-feed movements are brought about by an electrically contolled servo-motor, whose follow-up time is very short, so that the tool nose can follow the pattern of the desired non-circular shapes without any limitation of the cutting speed which are usual in turning.Type: GrantFiled: June 1, 1978Date of Patent: May 13, 1980Inventor: Roland Bathen
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Patent number: 4178537Abstract: The present invention relates to a method and apparatus for the production of an additional rotational motion of a helically toothed gear workpiece in an electronically, positively controlled gear processing machine operating according to the hobbing method which has separate rotating drives for workpiece and tool. In this process, a series of impulses are supplied to a controller. These impulses are compared to each other for the production of a control signal for the readjustment of the workpiece drive. The series of impulses are dependent upon the rate of rotation of each of the drives. An additional signal is supplied which is derived from the longitudinal advance of the workpiece in relation to the tool.Type: GrantFiled: May 11, 1978Date of Patent: December 11, 1979Assignee: Reishauer AGInventor: Arthur Angst
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Patent number: 4173786Abstract: A method and apparatus are disclosed for using a numerically controlled turning machine to automatically cut a thread in response to programmed data defining certain thread cutting parameters. The programmed data defines an initial thread cutting pass and the final thread depth. The method and apparatus cause the cutting tool to make a number of iterative thread cutting passes relative to the rotating workpiece with successive passes being made at correspondingly smaller cutting depths. The threading cycle is terminated by two finish passes at a predetermined minimum depth of cut.Type: GrantFiled: June 23, 1977Date of Patent: November 6, 1979Assignee: Cincinnati Milacron Inc.Inventors: Thomas J. Kuhnell, Randall C. Tanner, Alois V. Dryak
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Patent number: 4164693Abstract: A method and system for producing relative movement of an element along two perpendicular axes to closely approximate a desired path with the movement being sub-divided into a plurality of successive lengths with a determination being made of the number of steps for each axis that is needed to constitute each length. The number of steps in adjacent lengths on each axis is made to vary only within a constant amount so that the minimum and maximum lengths of each next length is determinable from its preceding length. The determination for each length involves calculating in one operation the deviation from the desired path for a minimum length and then calculating the addition of individual steps thereto within limits of deviation and velocity to arrive at the most acceptable length. This reduces the number of calculations as compared to prior known systems which calculate each individual step.Type: GrantFiled: May 30, 1974Date of Patent: August 14, 1979Assignee: The Superior Electric CompanyInventor: Albert C. Leenhouts
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Patent number: 4160937Abstract: A machine with automatic feed speed control comprising, a work-piece advancing device for advancing a work-piece in a feed path at a feed speed, a work-piece tooling device having a tool member movable in the feed path with a portion engageably with the work-piece for tooling the work-piece and for receiving a load from the advancing work-piece through the action of the work-piece advancing device. The load is proportional to the size of the portion of the tool member engaged with the work-piece. A speed controller is connected to the work-piece advancing device for increasing and decreasing the speed thereof and thereby increasing and decreasing the feed speed of the work-piece. Work-piece sensors are provided in the feed path engageably with the work-piece for sensing the size of the portion of the tool member which will become engaged with the work-piece, which size corresponds to a maximum load on the work-piece tooling device.Type: GrantFiled: July 15, 1977Date of Patent: July 10, 1979Inventor: Antonio Fiorini
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Patent number: 4150275Abstract: A control system, in an EDM machine, for simultaneously displacing the electrode tool and the electrode workpiece relative to each other along both an axis of penetration of the electrode tool into the workpiece and a translation motion in a plane perpendicular to the axis of penetration of the electrode tool into the workpiece. The control system consists of logic circuitry providing a variable signal obtained by integrating as a function of time the difference between a signal representative of the machining condition and a reference signal, apportioning the variable signal between a first and a second electrical signal and interrelating the apportionment with a control of the relative position of the electrodes along the axis of penetration and of the eccentricity of the relative translation movement, respectively, as a function of the first electrical signal and of the second electrical signal.Type: GrantFiled: September 29, 1977Date of Patent: April 17, 1979Assignee: Ateliers des Charmilles S.A.Inventor: Alain Wavre
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Patent number: 4150327Abstract: Automatic control of the machining process of a series of workpieces is effected by a computer-controlled machine tool in which the feed speed of a cutting tool is controlled automatically according to a program determined in a preliminary teaching mode in which a sample workpiece is machined by a cutting tool advancing at a constant spaced speed and in which signals representing working torque on the tool for different positions of the tool relative to the workpiece, modified to take into account cutting characteristics, are stored in a memory. During a subsequent adaptive cutting mode the tool feed speed for machining successive workpieces of a series is determined by processing reference signals extracted from the memory with signals representing the actual thickness of the stock to be machined to generate a signal controlling the instantaneous rate of tool advance, taking into account tool wear parameters.Type: GrantFiled: October 4, 1977Date of Patent: April 17, 1979Assignee: Instituto per le Ricerche di Tecnologia Meccanica RTMInventors: Antonino Camera, Alirio Dapiran, Gianluigi Divia'
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Patent number: 4143310Abstract: An apparatus for positioning is characterized by the fact that the circuit for generating a reference velocity, the existence of which is primarily responsible for the disadvantages in the conventional apparatus for positioning by analog feed-back of the velocity, is eliminated and a data processing unit is substituted for this circuit. Thus, the positioning is controlled by a group of predetermined reference velocity values stored beforehand in the memory of the data processing unit.Type: GrantFiled: December 1, 1976Date of Patent: March 6, 1979Assignee: Hitachi, Ltd.Inventors: Masaaki Fujinawa, Tatsuo Goto, Mineo Harada
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Patent number: 4140953Abstract: A programmable manipulator apparatus employs a memory for storing digital representations corresponding to different positions of the programmable manipulator in a number of different axes. The manipulator apparatus includes encoders for developing position signals representing the position of the manipulator in each of the axes. During repetitive work cycles, the stored digital signals in the memory are utilized as command signals and are compared with the encoder signals to move the manipulator to each set of positions in sequence corresponding to the various recorded positions as they appear in the memory. A program modification apparatus is provided to modify or correct certain manipulative positions of various sequence steps during the repetitive work cycles. The operator selects the program steps to be modified along with the desired positional modifications of the manipulator both as to magnitude and direction in the various axes as determined by his observations and/or results of the work cycle.Type: GrantFiled: March 3, 1976Date of Patent: February 20, 1979Assignee: Unimation, Inc.Inventor: Maurice J. Dunne
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Patent number: 4136302Abstract: A control system for a machine tool, such as a gear shaper, having a hydro-mechanically stroked cutter spindle, controls the stroking speed of the spindle, the feed of a workpiece relative to a cutter or other tool carried by the spindle, and the pressure of the fluid supplied to the hydraulic portion of the spindle stroking mechanism in such a way as to improve the efficiency of the machine both with regard to the time required to complete a given job and with regard to power consumption. The work force exerted by the spindle during its work stroke may be maintained within a selectable maximum limit and the cutter spindle stroking position is remotely adjustable to bring it into proper working relationship with a workpiece or to raise it to an elevated position to bring it out of working relationship with the workpiece. Various different stroking speeds of the spindle and various different feed rates of the workpiece relative to the spindle are available to suit different job requirements.Type: GrantFiled: January 10, 1977Date of Patent: January 23, 1979Assignee: Fellows CorporationInventors: Erich Tlaker, Clarence M. Nichols
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Patent number: 4131837Abstract: During machine tool operation a first set of sensors, referred to as cutter deflection sensors, provides data which is representative of the physical deflection of the cutting tool from a rest position, while a second set of sensors, referred to as position sensors, provides data which is representative of the position of the workpiece mounted on the machine tool relative to a reference or setpoint position. The cutter deflection and workpiece position data are combined to produce a resultant which is representative of the actual position of the cutting tool relative to the workpiece. This resultant is then compared with reference data which is representative of the desired position of the cutting tool relative to the workpiece. The difference between the actual and desired positions is then compared with a preselected tolerance value.Type: GrantFiled: July 13, 1977Date of Patent: December 26, 1978Assignee: The Boeing CompanyInventor: William J. Whetham
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Patent number: 4128796Abstract: There is disclosed a gap eliminator used for reducing working cycle time in machine tools. With over-all voltage variations in power sources in a factory taken into consideration, an output .function.(t.sub.0) under no or light load condition of an electric motor and an output k.function.(t) obtained by attenuating an output .function.(t) under loaded condition by an attenuator circuit are compared with each other to provide a primary signal, by which the feed rate is controlled. In this operation, particularly when an output obtained through a detecting circuit is an electric power, a circuit for eliminating periodic noise is disposed immediately after the electric power detector in order to eliminate adverse effects on power waves of periodic noise due to a belt. Further, abnormal overload condition is detected to provide a secondary signal, by which the machine is brought to a stop. Other merits and details of the arrangement will be made clear.Type: GrantFiled: March 29, 1976Date of Patent: December 5, 1978Assignee: NTN Toyo Bearing Company LimitedInventors: Yasuji Ohashi, Yoichiro Mitani
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Patent number: 4118660Abstract: An automatic machining system incorporating all the features of a numerically controlled type machine while eliminating the need for paper tapes. The tool receiving head incorporates means for identifying the moment of contact between tool and work piece, avoiding the need for inputting start position data. Motion control and drive means are provided for X, Y and Z head movement. The novel design provides drilling or punching by insertion of the proper tool in a head adapted to receive either tool.Visual displays provide step by step directions and allow for selection of the machining operation and sequential execution of the machining steps in accordance with inputted data requested by the display.The punching tool operates automatically simply under control of Z axis movement.Type: GrantFiled: January 5, 1977Date of Patent: October 3, 1978Assignee: Nippon Electric Company Ltd.Inventors: Nobuo Ohtsuki, Toshio Hayashi, Akio Imai, Yoshio Takahashi, Noboru Hashimoto
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Patent number: 4115858Abstract: A machine tool controller, for automatically controlling the Z axis operations of a machine tool, along a direction parallel with the axis of a tool-holding spindle, includes a system for executing programs in accordance with data which is manually entered into the system for each of a plurality of individual machining operations. The data, representative of two distances, respectively above and below the surface of the work to be machined, feed speed during machining and spindle rotating speed, may be manually entered through the keyboard of a control panel, or the two distances may be entered directly from a position counter which monitors the Z axis position of the spindle, and successful data entry is verified by indicator lights. All of the data for a single machining operation is stored in a memory unit, associated with the microprocessor system, at a single storage location, with each separate item of data stored in a specified memory location of the storage location.Type: GrantFiled: January 12, 1976Date of Patent: September 19, 1978Assignee: Houdaille Industries, Inc.Inventor: Menachen Kaufman
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Patent number: 4110674Abstract: A programmable feed control apparatus for controlling the feed movement of a machine member in response to control data of a feed control program stored in a program memory is disclosed wherein the programmable feed control apparatus includes a flip flop which is set by completion of the generation of a set of timing pulses in order to perform a feed movement of the machine member. The flip flop is reset when the feed movement is completed in order to generate another set of timing pulses to read out the control data.Type: GrantFiled: December 7, 1976Date of Patent: August 29, 1978Assignee: Toyoda-Koki Kabushiki KaishaInventor: Minoru Enomoto
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Patent number: 4109185Abstract: A servo system, particularly well suited for use in a computerized numerical control system for a large machine tool, in which a plurality of axis controlling servo circuits are controlled by one computerized axis controller. As each controlled axis moves, an attached resolver's output is digitized to generate a digital position feedback signal which is compared to the desired position in the computer. The resultant error signal is converted to an analog voltage to control said axis motion. A digital clock and counter drives two digital to analog converters to create the two resolver inputs, and supplies timing signals to the computer, thus synchronizing the system.Type: GrantFiled: December 27, 1976Date of Patent: August 22, 1978Assignee: McDonnell Douglas CorporationInventors: Stanley G. Froyd, Raymond C. Ue, John Paul Buchanan
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Patent number: 4103314Abstract: Positioning and motion control of two objects, for example, of a transducer and a disk record medium having tracks including pre-recorded servo information, is achieved in two modes of operation in the following manner:During a track following mode the transducer is connected in a closed servo loop and position error signals derived by the transducer are used to energize an actuator mechanism coupled to the transducer so as to maintain the transducer in the on-track position.During a track seek mode, the actuator is energized to cause the transducer to follow a desired velocity profile, at least a part of which is achieved with the transducer connected in a closed servo loop. The loop is fed with position error signals derived by the transducer sampled at times calculated to coincide with the on-track positions of a transducer following the desired velocity profile.Type: GrantFiled: June 14, 1977Date of Patent: July 25, 1978Assignee: International Business Machines CorporationInventor: William John Philip Case
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Patent number: 4096770Abstract: On a machine having a cutting tool moving relative to a rotating workpiece, a method and apparatus are disclosed for holding a constant relationship between the cutting tool and an angular position of the workpiece for different velocities of the cutting tool which produce correspondingly different following errors. The invention is applicable to a numerically controlled turning machine of the type maintaining a constant initial contact point between the cutting tool and an angular position of a rotating workpiece in response to a constant following error during successive machining passes. A first machining pass is executed in response to a first velocity signal which causes the cutting tool to initially contact the rotating workpiece at a first angular position thereof. Before the execution of a subsequent machining pass, the velocity signals associated with the first and subsequent machining passes are used to calculate the difference in following errors between machining passes.Type: GrantFiled: June 6, 1977Date of Patent: June 27, 1978Assignee: Cincinnati Milacron Inc.Inventor: Randall Curtis Tanner
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Patent number: 4095156Abstract: A device for automatic dimension control of extruded blanks comprises a means for measuring the blank width, having its output connected to an input of a third adder whose second input is connected to a means for presetting the blank dimensions and whose output is connected to the input of an amplifier-converter, a motor for driving the screw of an extruder, with an extruder screw rpm sensor, a motor for driving a drawing-off device, with a draw-off speed sensor, a means for presetting the draw-off speed, a first adder whose inputs are connected, respectively, to a means for presetting the extruder screw rpm and to said extruder screw rpm sensor and whose output is connected, via a first amplifier, to said screw drive motor, a second adder whose first input is connected to said draw-off speed sensor and whose output is connected, via a second amplifier, to said drawing-off device drive motor, a nonlinearity unit, a compensator unit, and a fourth adder whose first input is connected to the output of the compenType: GrantFiled: March 21, 1977Date of Patent: June 13, 1978Inventors: Vladimir Alexeevich Borisov, Ravil Abdrakhmanovich Akhmedzhanov, Jury Vsevolodovich Chistyakov
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Patent number: 4087731Abstract: A control system for moving a large machine along a single axis. The control system includes first and second position loop servo systems to drive at least respective first and second motors to move respective first and second sides of the machine in the direction of the single axis. The control system is comprised of means responsive to position error signals generated by each position loop servo system for generating a difference error signal that is indicative of the difference between the actual position of each respective side of the machine along the single axis, and means for coupling the difference error signal to means for driving at least one of the motors for causing a change in movement of that motor in a direction to move each side of the machine toward the same actual position while at the same time causing the difference error signal to be reduced toward zero.Type: GrantFiled: December 30, 1976Date of Patent: May 2, 1978Assignee: General Electric CompanyInventor: John M. Rhoades
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Patent number: 4086517Abstract: A system for controlling the operation of a numerically controlled machine tool used for cutting threads on workpieces, in which means are provided so that the quality of the products may not be adversely affected even when the thread cutting operation is interrupted for some reasons incidental to the thread cutting.Type: GrantFiled: April 6, 1976Date of Patent: April 25, 1978Assignee: Okuma Machinery Works Ltd.Inventors: Hiromi Yamaki, Hiroaki Arai
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Patent number: RE30132Abstract: A program control system is disclosed wherein the coordinates of a plurality of specified points of a prescribed path in the space to be traced by a manipulator assembly which are spaced apart from each other by a line segment of the same unit length are stored in a storage device in a teaching mode, and one set of coordinates of the adjacent specified points are simultaneously and sequentially read out from the storage device in a repeat mode so that the position command signals or coordinates of a plurality of interpolation points between the adjacent specified points are obtained by linear interpolation and are sequentially compared, at a predetermined time interval, with the actual or present positions of the manipulator assembly. The manipulator assembly is displaced at a velocity corresponding to the difference between the position command signal and the actual or present position signal so that the difference may become zero.Type: GrantFiled: March 3, 1978Date of Patent: October 30, 1979Assignee: Unimation, Inc.Inventor: Akiyoshi Irie