Installation for programmed control of a machine-tool

Claim 2

An installation for positioning a movable element of a machine-tool along a predetermined path, said installation comprising drive means including a rotatable lead screw coupled to said element, drive speed control means, stop means to discontinue the drive and stop said element when said element reaches a desired position along the path, a course positioning control including means for detecting a first position of said element ahead of said desired position and for detecting a second position of saId element between said first position and said desired position thereof, a fine positioning control including means coupled to said lead screw for producing within a full revolution thereof a control signal beginning when said element reaches a position intermediate said first and second positions and ending when said element reaches said desired position thereof, and actuating means for said drive speed control means and for said stop means, said actuating means being responsively coupled to said detecting means and being operable to cause said drive speed control means to reduce the drive speed when said detecting means detect said first position of the movable element and to condition said stop means to discontinue the drive when said detecting means detect said second position of the movable element, said control signal of said fine positioning control being coupled to said actuating means and being effective to override and prevent said actuating means from discontinuing the drive when said element reaches said second position and to allow said actuating means to stop the drive when said element reaches said desired position thereof.

Claim 3

An installation as claimed in claim 1, in which said fine positioning control includes a roll of fixed photosensitive elements selectively connected to an electrical circuit linked to a supply control device for said motor as a function of the exact position at which said carriage is to stop after slowing down in response to said course positioning control and, (b) at least one control window carried by a rotating mobile coding element between a light source and said roll of photosensitive elements and linked to said mechanism for controlling the drive to the carriage.

Claim 4

An installation as defined in claim 1, in which said course positioning control includes a perforated tape having several tracks based on the programs to be carried out, and a case of photosensitive elements, said tape and said photosensitive elements being carried, one by said carriage and the other by said carriage support.

Claim 5

An installation as defined in claim 1, in which said fine positioning control comprises a rotating coding element linked to said mechanism for controlling the drive and forming a moving aperture screen between a light source and photosensitive elements set at regular intervals in relation to said rotating coding element in a number corresponding to the precision required, and programmable means of preselection for the selective activating of said photosensitive elements, the whole unit being designed such that a complete revolution of said rotating coding element covers one length of travel of said carriage largely greater than the length of travel corresponding to the degree of precision of said course positioning control.

Claim 6

An installation as claimed in claim 4 in which said course positioning control includes means for counting the revolutions of said rotating coding element of said fine positioning control.

Claim 7

Installation as claimed in claim 5, in which said rotating coding element itself produces, with each revolution, an impulse for controlling the drive of a counter.

Claim 8

Installation as claimed in claim 4 additionally including adjustable manual means of preselection for the selective activating of said photosensitive elements of said fine positioning control means, and means of inversion for selectively placing said photosensitive elements either in a state of dependence on said programmed preselection means or in a state of dependence on said adjustable manual means for preselection.

Claim 9

Installation as claimed in claim 7, in which the adjustable manual means for preselection for the selective activating of the said photosensitive elements are made up of switches inserted into the supply circuits for said photosensitive elements.

Claim 10

An installation for programmed control of a machine-tool of the type comprising, for each carriage, a mechanism for controlling the drive link to a motor and a system fOr controlling the supply to said motor, said installation including means for the detection of approach having a relatively average accuracy of the order of 0.3 mm., by default, said approach detection means being capable of covering on their own the total these two pitches having a single interval of circumferential length substantially equal to that of the mask of the first stage of detection.

Claim 11

An installation for programmed control of a machine-tool of the type comprising, for each carriage, a mechanism for controlling the drive link to a motor and a system fOr controlling the supply to said motor, said installation including means for the detection of approach having a relatively average accuracy of the order of 0.3 mm., by default, said approach detection means being capable of covering on their own the total these two pitches having a single interval of circumferential length substantially equal to that of the mask of the first stage of detection.

Claim 12

Installation as claimed in claim 9, in which each of the two stages comprises 10 photosensitive elements which are equidistant, the mask of the first stage extending over an arc covering two successive intervals between two photosensitive elements, the angle of the phase displacement of the lights of the second stage being equal to a fifth of the angle between two successive photosensitive elements, and the angle of the longest part between the windows of the second stage being equal to the angle of the mask of the first stage increased, at each of its two ends, by the angle of the displacement of phase, the photosensitive elements in odd order or those in even order in the second stage being selectively put into service condition according to whether the mask of the first stage is working itself in conjunction with a photosensitive element of odd or equal order.

Claim 13

An installation as claimed in claim 10, in which one revolution of the rotating coding element corresponds to a move forward of 1 mm. of the controlled member, the angle between two successive photosensitive elements being equal to one-tenth of the circumference corresponding to a travel of 0.1 mm. of the controlled member and the angle of displacement of phase being equal to one-fiftieths of the circumference corresponding to 0.02 mm. advance of the controlled member.

Claim 14

An installation as claimed in claim 7, in which the means for counting the revolution of the rotating coding element include a counting unit set at each sequence for a predetermined number of revolutions programmed by adding a signal to the matrix, the backwards count of this counting unit taking place in response to the impulses at each revolution of the rotating coding element, and wherein the adjustable manual means of preselection include a set of switches for setting the counting unit to any number of revolutions desired.

Claim 15

An installation as claimed in claim 2, in which the first stage of detection includes a number of equidistant photosensitive elements one-fiftieth a mask extending over an arc covering at least one successive interval between said photosensitive elements, and wherein the windows of the second stage of detection are equidistant and the photosensitive elements of the second stage detection are arranged according to a spacing smaller than that of said windows to the value of an angle of displacement of phase equal to one-fiftieth of the circumference corresponding to 0.02 mm. advance of the control member and distributed over an arc less than 360*.

Claim 16

Installation as claimed in claim 13, in which the arc covered by said mask corresponds to several said intervals.

Claim 17

Installation as claimed in claim 13 including more than two stages of detection, the additional stages being supplemental and having a finer or larger definition than the second stage of detection mentioned.

Claim 18

Installation as claimed in claim 13 in which the number of photosensitive elements in the second stage of detection is equal to the number of corresponding windows in the rotating coding element.

Claim 19

Installation as claimed in claim 2, in which the width of the windows of the rotating coding element is determined as a function of the inertia of the movement control of the member driven by the machine.

Claim 20

Installation as claimed in claim 2, in which the rotating coding element is in the form of a disc and its windows are formed from holes made in this disc on a same circumference.

Claim 21

Installation as claimed in claim 9, in which, against the mask, counter-maSk is applied having the same profile as the mask and which has, in addition, a row of windows identical to those of the second stage of the rotating coding element of detection, said counter-mask being fixed to the mask in an angularly adjustable manner to permit the reduction of the effective width of the above-mentioned windows as a function of the inertia of the movement control of the corresponding carriage.

Claim 22

An installation for programmed control of a machine-tool of the type comprising, for each carriage, a mechanism for controlling the drive link to a motor and a system for controlling the supply to said motor, said installation including means for the detection of approach having a relatively average accuracy of the order of 0.3 mm., by default, said approach detection means being capable of covering on their own the total extend of travel of the carriage; and means for the detection of stopping having a relatively high accuracy of the order of 0.02 mm; and wherein said system for controlling the supply to said motor is connected through appropriate connecting means to selectively be commanded by said approach detection means, the information extent of travel of the carriage; and means for the detection of stopping having a relatively high accuracy of the order of 0.02 mm.; and wherein said system for controlling the supply to said motor is connected through appropriate connecting means to selectively be commanded by said approach detection means, the information supplied by said approach detection means causing the supply of current to said motor to change so as to slow down said motor to a constant minimum speed and at the same time conditioning said connecting means so that said supply control system is put under the control of said stop detection means, the information supplied by said stop detection means subsequently causing cutting off of said supply to the motor in order to ensure the precise stopping of said carriage, and in which the rotating coding element has at least two stages of detection, a first stage which includes, to the right of a first annular roll of photosensitive elements, a mask extending along a circumferential length greater than that corresponding to the angle of rotation of said rotating coding element which is driven by inertia after the control signal for precise stopping, and a second stage including, to the right of a second annular roll of photosensitive elements, several windows whose pitch is of an angle, in relation to the pitch of said corresponding photosensitive elements, of phase displacement equal to the smallest unit which it is desired to control, i.e., an angle corresponding to the definition which it is desired to obtain in stopping the control member, by substantially forming a vernier with one of supplied by said approach detection means causing the supply of current to said motor to change so as to slow down said motor to a constant minimum speed and at the same time conditioning said connecting means so that said supply control system is put under the control of said stop detection means, the information supplied by said stop detection means subsequently causing cutting off of said supply to the motor in order to ensure the precise stopping of said carriage, and wherein said programmable preselection means for the selective activating of said photosensitive elements includes a matrix the columns of which are supplied successively by a step-by-step selector switch placed in a state of dependence on said approach detection means, the lines of this matrix being placed, respectively, into circuit for supplying said photosensitive elements, preselection being determined by the positioning of pins pushed into the involved points of intersection of the columns and the lines of the matrix.

Claim 23

An installation for programmed control of a machine-tool of the type comprising, for each carriage, a mechanism for controlling the drive link to a motor and a system for controlling the supply to said motor, said installation including means for the detection of approach having a relatively average accuracy of the order of 0.3 mm., by default, said approach detection means being capable of covering on their own the total extend of travel of the carriage; and means for the detection of stopping having a relatively high accuracy of the order of 0.02 mm; and wherein said system for controlling the supply to said motor is connected through appropriate connecting means to selectively be commanded by said approach detection means, the information extent of travel of the carriage; and means for the detection of stopping having a relatively high accuracy of the order of 0.02 mm.; and wherein said system for controlling the supply to said motor is connected through appropriate connecting means to selectively be commanded by said approach detection means, the information supplied by said approach detection means causing the supply of current to said motor to change so as to slow down said motor to a constant minimum speed and at the same time conditioning said connecting means so that said supply control system is put under the control of said stop detection means, the information supplied by said stop detection means subsequently causing cutting off of said supply to the motor in order to ensure the precise stopping of said carriage, and in which the rotating coding element has at least two stages of detection, a first stage which includes, to the right of a first annular roll of photosensitive elements, a mask extending along a circumferential length greater than that corresponding to the angle of rotation of said rotating coding element which is driven by inertia after the control signal for precise stopping, and a second stage including, to the right of a second annular roll of photosensitive elements, several windows whose pitch is of an angle, in relation to the pitch of said corresponding photosensitive elements, of phase displacement equal to the smallest unit which it is desired to control, i.e., an angle corresponding to the definition which it is desired to obtain in stopping the control member, by substantially forming a vernier with one of supplied by said approach detection means causing the supply of current to said motor to change so as to slow down said motor to a constant minimum speed and at the same time conditioning said connecting means so that said supply control system is put under the control of said stop detection means, the information supplied by said stop detection means subsequently causing cutting off of said supply to the motor in order to ensure the precise stopping of said carriage, and wherein said programmable preselection means for the selective activating of said photosensitive elements includes a matrix the columns of which are supplied successively by a step-by-step selector switch placed in a state of dependence on said approach detection means, the lines of this matrix being placed, respectively, into circuit for supplying said photosensitive elements, preselection being determined by the positioning of pins pushed into the involved points of intersection of the columns and the lines of the matrix.