EP0918593A1 - Actionneur electromecanique - Google Patents

Actionneur electromecanique

Info

Publication number
EP0918593A1
EP0918593A1 EP97926131A EP97926131A EP0918593A1 EP 0918593 A1 EP0918593 A1 EP 0918593A1 EP 97926131 A EP97926131 A EP 97926131A EP 97926131 A EP97926131 A EP 97926131A EP 0918593 A1 EP0918593 A1 EP 0918593A1
Authority
EP
European Patent Office
Prior art keywords
lathe
actuator
spindle
tool
piezoelectric
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP97926131A
Other languages
German (de)
English (en)
Inventor
Nicholas Paige
Gerard Mccavana
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Precitech Inc
Original Assignee
Taylor Hobson Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Taylor Hobson Ltd filed Critical Taylor Hobson Ltd
Publication of EP0918593A1 publication Critical patent/EP0918593A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
    • H02N2/02—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing linear motion, e.g. actuators; Linear positioners ; Linear motors
    • H02N2/04—Constructional details
    • H02N2/043—Mechanical transmission means, e.g. for stroke amplification
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
    • B23Q1/25—Movable or adjustable work or tool supports
    • B23Q1/26—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members
    • B23Q1/34—Relative movement obtained by use of deformable elements, e.g. piezoelectric, magnetostrictive, elastic or thermally-dilatable elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q5/00—Driving or feeding mechanisms; Control arrangements therefor
    • B23Q5/02—Driving main working members
    • B23Q5/027—Driving main working members reciprocating members
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
    • B24B1/04—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes subjecting the grinding or polishing tools, the abrading or polishing medium or work to vibration, e.g. grinding with ultrasonic frequency
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B13/00—Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor
    • B24B13/0025—Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor for contact lenses
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
    • H02N2/02—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing linear motion, e.g. actuators; Linear positioners ; Linear motors
    • H02N2/06—Drive circuits; Control arrangements or methods
    • H02N2/062—Small signal circuits; Means for controlling position or derived quantities, e.g. for removing hysteresis

Definitions

  • the present invention concerns a controllable actuator and also the machine tools which employ such an actuator.
  • a concern of the present invention is to provide an actuator which can carry out rapid and accurate reciprocatory movements .
  • an actuator comprising a pair of similar devices each responsive to electrical signals to generate reciprocatory displacements, and link means coupled to the devices to translate the respective displacements of the devices into a single set of reciprocatory displacements, the coupling between the link means and the devices being such that for each displacement generated by the link means the devices generate displacements in opposite directions.
  • non- rotationally symmetrical surfaces can be generated using turning machines by additional movement of the cutting tool relative to the surface being turned along the axis of the spindle and in synchronism with the spindle rotation.
  • U.S. Patent Specification No. 4,680,998 discloses a lathe for use in the manufacture of contact lenses.
  • the lathe is what is known as an Rho- ⁇ lathe as distinct from an x-y lathe in that movement of the tool relative to the lens being turned has one major linear component with the second major component of tool movement being arcuate.
  • Both x-y and Rho- ⁇ lathes have been used in turning operations long before the development of the fast tool servo.
  • the movement of a tool in accordance with the x and y slides of an x-y lathe or the arcuate and linear movement of a Rho- ⁇ lathe will hereinafter be referred to as macro-movements.
  • the cutting tool is given, as described in the D.C. Thompson paper for example, an additional micro-movement component which is synchronised with the rotation of lathe spindle.
  • a lathe for machining non- axially symmetrical surfaces comprising means for moving a cutting tool holder relative to a workpiece mounted on the lathe spindle so that a rotationally symmetrical surface can be machined in the workpiece, fast tool servo means for imparting in synchronism with the rotation of the lathe spindle an additional movement to the cutting tool holder so that a non-rotationally symmetrical surface can be cut in a workpiece, wherein the means for moving the tool holder comprise a piezoelectric actuator.
  • Figure 1 is a diagrammatic plan view of an x-y lathe
  • Figure 2 is a side view of an actual lathe
  • Figure 3 is a perspective view of the fast servo tool of the lathe of Figure 2;
  • Figure 3A is a side section view through the fast servo tool of the lathe of Figure 2 taken in a vertical plane along the spindle axis of the lathe;
  • Figure 4 is a rear view of the fast tool servo as indicated by line IV-IV of Figure 3A;
  • Figures 5A and 5B are respectively side and front views of a damping arrangement used in the fast servo tool of Figures 3 and 4;
  • Figure 6 is a plan view of an embodiment of a multi- tool head
  • Figure 7 is a block diagram of a control system used for the fast tool servo of Figures 3 and 4; and Figure 8 is a block diagram showing the overall control circuitry used in the lathe of Figures 1 and 2;
  • Figure 9 is a block diagram of part of the circuit of Figure 8 in greater detail.
  • Figure 10 is a block diagram of a circuit forming part of Figure 9.
  • Figure 11 is a diagrammatic plan view of a Rho- ⁇ lathe.
  • a lathe 1 which comprises a spindle 2 having a collet 3 on which can be mounted a lens blank.
  • the spindle 2 is mounted on a linear slide 4 capable of controlled movement along the z axis.
  • a diamond point cutting tool 5 is mounted on a fast tool servo 6 carried by a slide 7 controllably movable in the x direction which is orthogonal to the movement of the slide 4.
  • the slides 4 and 7 provided normal, macro-movements of the tools of the kind which could be used to generate rotationally symmetrical surfaces whilst the fast tool servo 6 carries out the micro-movements necessary to create non-axially symmetrical or torroidal surfaces.
  • a shaft encoder 8 generates signal synchronised with the rotation of the lathe spindle.
  • Figure 2 of the drawings is a side view showing the main components of an actual lathe constructed in accordance with an embodiment of the present invention. In this figure integers common with figure 1 have been given the same reference numerals.
  • 20 is a video display unit used by the lathe operator to display input parameters etc together with a switch console 21 controlling off and on operation of the lathe.
  • the main components of the lathe are conventional and as shown in Figure 1 include the spindle 2 mounted on a Z-slide 4 so as to be movable in the z direction carrying a conventional collet on which a lens blank as a workpiece can be mounted.
  • This fast tool servo includes a diamond cutting tool and is mounted on the x slide 7 of the lathe. As with the z slide the arrangement of the x slide is entirely conventional.
  • each slide is movable a nut mounted on a rotary screw which is driven by a DC motor.
  • Mounted on the main body of the lathe closely adjacent to each slide is an 8 nanometre diffraction grating. Light shone onto this grating is reflected onto sensors on the slide which count interference fringes as the slide is moved relative to the grating. The resulting signal is used in a feedback control loop be to control the rotation of the associated DC motor.
  • the arrangement of the screws, nuts, gratings and sensors is entirely conventional and does not form part of the present invention.
  • FIG. 3 of the accompanying drawings this in combination with Figures 3A and 4 shows the fast tool servo 6 in greater detail.
  • a pair of piezoelectric stacks or actuators 31 each stack consisting of a plurality of piezoelectric elements.
  • These actuator stacks act on a T-lever 32 having a cross-piece 33 and lever arms 34.
  • the lower end of lever arms 34 of the T-lever are coupled by a stiff metallic coupling 35 to a tool beam 36 on which is mounted the diamond cutting tool.
  • the tool beam 36 is capable of horizontal movement in directions shown by the arrow A which are parallel to the Z axis of the Z slide 4 and to the rotational axis of the spindle 2.
  • This metallic coupling can be a single sheet of metal but in the present embodiment is formed by a pair of parallel strips of spring steel.
  • the tool beam 36 has a tool post 36' on which a tool can be mounted and is supported by two sets of vertical springs or ligaments shown at 36A and 36B which provide resistance to the horizontal movement and also act to provide rigidity in the direction of movement. These vertical springs are firmly mounted in the base plate of the fast tool servo. As can be seen from Figure 4, the T-beam has two dependent arms 34 and these arms carry vane dampers 49, the purpose of which will be described later.
  • the actuators 31 are mounted on a base plate 38 secured to the side walls 39 of the fast tool servo.
  • the actuators 31 are held in tension between the crosspiece 33 and the base plate 38 in a manner which will be described hereinafter, the cross piece 33 being of composite construction.
  • the crosspiece 33 comprises a pair of parallel bars or blocks 40, 41.
  • Sandwiched between the upper surfaces of the actuators 31 and the lower of the two blocks (41) are a pair of roller bars 42.
  • Another roller bar 43 is sandwiched between the blocks 40, 41 and an adjustable bolt 44 is housed in a threaded hole on upper block 40.
  • Each roller bar comprises a rod of metal which is circular in cross- section.
  • the crosspiece includes an arrangement which also includes a threaded bolt 44 which holds in tension a metal flexure 45 secured to a cross pin 46.
  • the metal flexure 45 extends freely through a slot 43' in the lower bar 43 and is held in the upper bar 33.
  • the actuators 31 are held compressed between the upper bar 33 acting via the bolt 44 and roller bar 41 onto the lower bar 43 and the base plate 38 by a resilient force exerted by the metal flexure 45.
  • the movements of the lever 34 are shown in Figure 3 by the arrows A.
  • a block 47 is mounted on the side walls 39 of the fast tool servo and is connected to the lower block 40 by a flexure 48.
  • the flexures 45 and 48 comprise sheet metal strips.
  • the actuators 31 are alternately provided with a voltage in anti-phase and in the order of several hundred volts so that whilst one actuator is expanding the other is contracting.
  • Each of the piezoelectric actuators contracts when positively energised and expands when negatively energised.
  • the effect of this is that the T-lever 32 is rocked as described about a central axis defined by the flexure 45 so as to provide short, highly controlled linear movements of the tool beam 36 parallel to the Z axis of the lathe.
  • the position of the tool beam 36, and thus of the cutting tool is measured by what is known as a Linear Voltage Differential Transformer (LVDT) .
  • the LVDT is shown at 50 in Figure 3 and comprises a central shaft which moves with the tool beam 36 relative to pick-up coils to provide an output signal corresponding to its displacement.
  • This device 50 is entirely conventional.
  • the tool beam 36 is mounted for reciprocal movement between a pair of side plates 36' ' mounted on the base of the fast tool servo and onto which is secured the fixed portion of the LYDT50.
  • FIG. 5A shows a side view of one of the vane dampers 49.
  • the vane dampers are made from 0.25 mm thick beryllium copper plates and are mounted in slots in respective damping blocks 49' secured to the base of the tool post by mounting bolts 38.
  • a 10,000 centistoke damping fluid is also provided in the slots in the damping blocks and the result is that the vane dampers provide a moving damper which is extremely stiff in the axis of motion plus being compliant in the other axis .
  • This compliance is provided by the freedom of the vanes to bend and flex due to their 0.25 mm thickness.
  • the 0.25 mm thickness means that the vanes have minimum mass . This is another important requirement given the rapid accelerations and decelerations that the fast tool servo has to carry out.
  • the damping fluid will be silicon based and the nominal gap between each face of a vane and its related opposite damping face would be 0.008 inches.
  • FIG. 6 of the accompanying drawings this shows a possible multi-tool arrangement in which the fast tool servo 6 is mounted on slide 4 in combination with four other standard tool holders .
  • the diamond cutting tool of the fast tool servo is shown at 55
  • the conventional tool holders are shown at 52, 53, 54 and 56.
  • Tool holder 52 is empty
  • tool holder 53 carries a power curve roughing tool 43A
  • tool holder 54 carries a base curve finish tool 44A
  • tool holder 56 carries a base curve roughing tool 45A.
  • These additional tools can be used for machining non- toric surfaces and the arrangement shown in the figure means that a contact lens can be machined from a blank to its finished state without replacing tool heads.
  • 57 is a conventional LVDT probe which can be used to measure the position of the lens blank.
  • the linearity of operation can be improved.
  • This relationship between a linearity and charge is because piezoelectric actuators behave electrically like variable capacitors.
  • embodiment reference capacitors 60, 61 are placed in series with the pair of piezoelectric actuators 31.
  • any change in charge across a piezoelectric actuator will result in a corresponding change in charge across its associated reference capacitor.
  • the capacitance of each piezoelectric actuator will change but since the capacitance of the associated reference capacitors remains constant, a voltage across each reference capacitor 60, 61 is proportional to charge across its associated piezoelectric actuator.
  • the displacement of each piezoelectric actuator is nearly linear with the voltage across its reference capacitor.
  • the voltages across the reference capacitors 60, 61 are used in a feedback loop to control the displacements of their associated piezoelectric actuators. It will be appreciated that if the capacity of the reference capacitor is large compared to the capacitance of its associated piezoelectric actuator, most of the voltage across the combination of piezoelectric actuator and capacitor is across the piezoelectric actuator. As each actuator is driven to hundreds of volts the presence of a large reference capacitor reduces the voltages for the feedback loop to normal signal levels of several volts.
  • the piezoelectric actuators are driven by associated high voltage amplifiers 62, 63.
  • each reference capacitor may operate at several hundred volts relative to ground. Any connection to the reference capacitor to sense the voltage must be of high impedance to avoid loading the high voltage circuit. It is possible to measure the reference capacitor voltage with a pair of voltage dividers to reduce the common mode voltage leading to the associated amplifier. However it is difficult to match the resistors in the divider network for good common mode rejection and the resulting signal- to-noise ratio may cause problems.
  • the present embodiment employs a pair of isolation amplifiers 64, 65 mounted across the reference capacitors 60, 61. This provides both high impedance and good common mode rejection.
  • the outputs of the isolation amplifiers 64, 65 are taken to respective summing circuits 66, 67 where they are combined with an error signal derived both from the main control system for the lathe as a whole and with a position signal generated by the position sensor 50.
  • the control circuit of one actuator incorporates an inverter 68.
  • the piezoelectric actuators and their reference capacitors will have some leakage. This leakage works as a resistor in parallel with the capacitor which tends to discharge the capacitor. The leakage for piezoelectrics is quite low and reference capacitors are available with low leakage as well. However if the reference capacitor discharges to zero the position loop will still be able to maintain position because the high voltage amplifier will be able to supply full voltage to the piezoelectric. In fact if the feedback voltage from the reference capacitor is zero the charge loop merely acts as an additional gain in series with the position loop gain. If the actuator discharges faster than the reference capacitor eventually all the voltage available from the high voltage amplifier will be across the reference capacitor and the actuator will not move. In order to combat this the present embodiment provides an intentionally added leakage resistance to each reference capacitor so as to ensure that the reference capacitors discharge faster than their associated actuators. These leakage or shunt resistors are shown in Figure 7 at 69.
  • the addition of the shunt resistors 69 to the reference capacitors also solves the problem of initial conditions at start-up. Before the circuit is switched on there may be a mismatch between the charge on the piezoelectric actuator and its associated reference capacitor. If the difference is large enough there will be a large error signal in the charge loop and the charge loop will go into saturation at start-up. The actuator will go- to one extreme or the other despite the position loop attempting to drive the actuator to the correct position. The shunt resistor will eventually reduce the feedback signal from the reference capacitor to zero allowing the position loop to drive the actuator to the correct position.
  • the position signal from the position sensor 50 can be demodulated using peak sampling techniques to ensure that bandwidth is not limited by carrier frequency and introduce negligible phase shifts in the feed back loop.
  • simple demodulation is carried out in circuit 70.
  • This position output is supplied to a summing junction 71 and is compared in this summing junction with an analogue position demand signal supplied at input 72 of the summing junction from the main control circuitry of the lathe.
  • the resulting error signal on line 73 drives the amplifiers 62, 63 via circuit 74.
  • This circuit is what is known as a forward loop controller and is matched for the characteristics of the subsequent drive circuitry of the actuator and the physical constraints of the fast tool servo. It includes a phase advance circuit, low frequency filters, and a notch filter tuned to the natural frequency of the fast tool servo.
  • the fast tool servo be carefully synchronised with the x and y slide motions of the main lathe to maintain accuracy.
  • the fast tool servo feedback control loop is independent of the x and z slide control.
  • it is essential that the linear movements of the diamond cutting tool are synchronised with the rotation of the main lathe spindle in order to enable toric surfaces to be machined. This is achieved by the shaft encoder 8 which is an incremental encoder and is mounted on the end of spindle 2, and by the overall control circuitry of the lathe.
  • This control system comprises what is known as a PMAC (TM) controller 80.
  • PMAC stands for "Programmable Multi Axis Controller” and the controller 80 is manufactured by the Delta Tau Corporation of the United States of America.
  • the controller 80 receives an input from the shaft encoder 8 which provides a time based master for the entire controller.
  • the PMAC carries out a motion programme controlling the operation of both the lathe in the x and z axes and the linear motion of the fast tool servo its speed of execution is directly proportional to the frequency of the master encoder.
  • the PMAC controller 80 automatically handles any deviation from the time base master and scales the speed of execution in direct proportion. This technique allows the entire trajectory of the cutting tool relative to the blank to be calculated off-line.
  • the procedure for generating a toric shape is as follows. All the trajectory information required to control the fast tool servo and the main X and Z slides is generated prior to the machining operation and stored in a job file indicated at 81.
  • This job file is generated by a general purpose computer 86. The contents of this job file are streamed into the PMAC controller 80 via a dual port RAM 81 and into a rotary buffer 83. Essentially this buffer 83 stores the required coordinates and reads these coordinates out in synchronism with the time base clock generated by the clock circuit 84 from the output of the shaft encoder 8.
  • the PMAC 80 includes a control processor 85 which not only computes the control signals for the macro movements of the z axis and x axis of the lathe and the micro movements of the fast tool servo but also includes a spline interpolation mode so that every point in the trajectory of the cutting tool does not have to be programmed.
  • the spline interpolation mode computes nine intermediate points per programme point. Accordingly by using 24 programme points per revolution, that is a point every 15 degrees, the worst interpolation errors are negligible.
  • the embodiment described also has the ability to control the orientation of the meridian of the lens workpiece to better than ⁇ 1 degree. This is achieved in the control system by freezing and arming the time base so as to capture the spindle position and then comparing the captured spindle position with the programmed meridian orientation stored in the job file. This comparison is carried out in a compare register in the controller. Once the spindle position has been established with respect to the required orientation the time base is triggered by the output of the compare register and this ensures synchronisation with the workpiece spindle.
  • the controller 80 is shown in greater detail in Figure 9 of the drawings.
  • the basic PMAC controller is capable of controlling 8 axes. In the present embodiment control of only 3 axes is required, namely the X and Z axes of the lathe and the W axis which represents the movement of the fast tool servo.
  • this shows the DSP-gate 89 which is used to control the meridian orientation in the manner already described in the specification. It will be seen that this gate has seven main registers 100-106. In the present embodiment the registers 104 and 105 are not used. Of the registers used, register 102 is a control register which has access to all the other registers and which communicates with the control circuit 80 via a bus and data control circuit
  • Register 101 is a 24-bit up/down position register and the master clock derived from shaft encoder 8 is supplied to register 101 via a digital filter 109 and a decode circuit 112. The register 101 is thus a continuous indication of the spindle position.
  • Register 100 is referred to as a servo position capture register and is supplied on line 113 with an index signal derived from the shaft encoder which indicates the starting point of a spindle revolution.
  • the servo position capture register 100 when clocked by the index signal acts to capture the value in register 101.
  • Register 103 is referred to as a position compare register and has a value loaded into it via the control register 102 which is to be compared with the value of the position register 101.
  • the value loaded by the control register is the value as captured in the servo position capture register together with an operator offset, a program offset and appropriating timing bias.
  • the values of position compare register 103 and of position register 101 are compared at a gate 108 and on parity between the contents of the two registers a signal is sent from gate 108 both to the control register 102 and as a flag to a position capture trigger control circuit 113.
  • the output of circuit 113 triggers a home capture register 106 the output 114 of which provides an external time base trigger to circuit 80.
  • FIG 11 of the accompanying drawings shows a fast tool servo of the kind described mounted on a Rho/ ⁇ lathe.
  • the lathe comprises a spindle 90 for carrying a workpiece such as a lens blank.
  • the fast tool servo is shown at 91 and is mounted on an arm 92 pivotally mounted at 93 or a slide 94 movable as shown by the arrows X over the base 95 of the lathe in the direction of the spindle axis.
  • the operation of the fast tool servo is synchronised with the spindle revolution so as to be capable of cutting axially non-symmetrical shapes.

Abstract

L'invention concerne un actionneur comprenant une paire d'appareils semblables répondant chacun à des signaux électriques pour provoquer des déplacements alternatifs, et des moyens de liaison accouplés aux appareils pour transformer les déplacements respectifs des appareils en une seule série de déplacements alternatifs; le couplage entre le moyen de liaison et les appareils est tel qu'à chaque déplacement provoqué par le moyen de liaison, les appareils provoquent des déplacements dans des directions opposées.
EP97926131A 1996-06-17 1997-06-16 Actionneur electromecanique Withdrawn EP0918593A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB9612614A GB2314452A (en) 1996-06-17 1996-06-17 Electromechanical actuator
GB9612614 1996-06-17
PCT/GB1997/001621 WO1997048521A1 (fr) 1996-06-17 1997-06-16 Actionneur electromecanique

Publications (1)

Publication Number Publication Date
EP0918593A1 true EP0918593A1 (fr) 1999-06-02

Family

ID=10795406

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97926131A Withdrawn EP0918593A1 (fr) 1996-06-17 1997-06-16 Actionneur electromecanique

Country Status (4)

Country Link
EP (1) EP0918593A1 (fr)
JP (1) JP2000512566A (fr)
GB (1) GB2314452A (fr)
WO (1) WO1997048521A1 (fr)

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EP1787749B1 (fr) 2004-04-23 2008-10-08 Schott AG Dispositif pour la production de microstructures
DE102004020990B4 (de) * 2004-04-23 2008-05-21 Schott Ag Vorrichtung und Verfahren zur Erzeugung von Mikrostrukturen
DE102005042107A1 (de) * 2005-09-05 2007-03-15 Siemens Ag Schaltung und Verfahren zur Ansteuerung eines piezoelektrischen oder elektrostriktiven Aktors
US7293487B2 (en) 2005-11-15 2007-11-13 3M Innovative Properties Company Cutting tool having variable and independent movement in an x-direction and a z-direction into and laterally along a work piece for making microstructures
US7350441B2 (en) 2005-11-15 2008-04-01 3M Innovative Properties Company Cutting tool having variable movement at two simultaneously independent speeds in an x-direction into a work piece for making microstructures
US7350442B2 (en) 2005-11-15 2008-04-01 3M Innovative Properties Company Cutting tool having variable movement in a z-direction laterally along a work piece for making microstructures
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US7328638B2 (en) 2005-12-27 2008-02-12 3M Innovative Properties Company Cutting tool using interrupted cut fast tool servo
US7677146B2 (en) 2006-05-10 2010-03-16 3M Innovative Properties Company Cutting tool using one or more machined tool tips in a continuous or interrupted cut fast tool servo
US7628100B2 (en) 2007-01-05 2009-12-08 3M Innovative Properties Company Cutting tool using one or more machined tool tips with diffractive features in a continuous or interrupted cut fast tool servo
US7669508B2 (en) 2007-10-29 2010-03-02 3M Innovative Properties Company Cutting tool using one or more machined tool tips with diffractive features
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CN110227983A (zh) * 2019-06-17 2019-09-13 南方科技大学 非球面光学元器件抛光装置
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Also Published As

Publication number Publication date
JP2000512566A (ja) 2000-09-26
GB2314452A (en) 1997-12-24
GB9612614D0 (en) 1996-08-21
WO1997048521A1 (fr) 1997-12-24

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