US3533322A

US3533322A - Automatic control device for a machine-tool

Info

Publication number: US3533322A
Authority: US
Inventors: Georges Edmond Offenstadt
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-04-06
Filing date: 1968-04-02
Publication date: 1970-10-13
Anticipated expiration: 1987-10-13
Also published as: DE1763032A1; GB1214910A; FR1527949A

Description

United States Patent I Inventor Georges Edmond Oll'enstadt 27 Ave. de Versailles Seine. Paris, France Appl. No. 718,164 Filed April 2, l98 Patented Oct. 13, 1970 Priority April 6. 1967 France AUTOMATIC CONTROL DEVICE FOR A MACHINE-TOOL 5 Claims, 4 Drawing Figs.

References Cited Primary Examiner-Frank T. Yost Attorney Steinberg and Blake ABSTRACT: Acontrol device for a machine-tool such as a cutting press or punching machine comprising detecting L'.S. (,l 83/534. means mounted on the pressing plate of said machine and 83/365, 83/368 adapted to detect, during the travel of said plate in a given Int. Cl B26d 5/08 direction, the place of the cutting die or tool on the work sup- Field of Search 83/365. ported by a stationary table and to deliver the corresponding 368, 370, 534, 536. 537: 72/(lnquired); information to a programme device adapted to control the difl (10/ I nquired) ferent operational stages of said plate.

A L S o S b Patented Oct. 13, 1970 I V Y 3,533,322

Sheet 2 of 2 'IIF- meats 51mm OfFEr/sTADT By: 7-

AUTOMATIC CONTROL DEVICE FOR A MACHINE- TOOL The present invention essentially relates to an automatic control device for a machine-tool such as a press, a punching. shapingor like machine. More particularly, said device is intended to control, in such a machine, a movable unit cooperating with a stationary unit with respect to which it should take a given position, for instance to control the pressing plate, translatorily movable in horizontal and vertical directions, ofthe punching-machine, said plate being provided to be placed above the punching tool, then to exert a pressure on it so as to make it engage into the work to cut the latter.

In the presently known machines of this type, the proper positioning of the movable unit with respect to the stationary unit is performed by a manual control. Thus, for instance, in the case of a punchingmachine, the positioning of the pressing plate above the tool is effected by the operator himselfwho determines by guesswork the moment where the plate is plumb above the tool, then starts the vertical motion of said plate resulting in the punching out of the material. This method does not permit a precise positioning of the plate and involves moreover considerable losses in time.

It is also possible to provide the machine with adjustable means effecting an automatic stop of the plate when it is exactly above the tool for instance. For a given tool in a given position on the plate of the machine, these stop means may be preadjusted so as to make the plate stop automatically at the wanted stop during each processing. However, a new adjustment must be performed each time the position of the die or cutting tool on the work carried by the punching table is changed or when a different type of tool is used. lt is in addition necessary to provide adjustable means to determine the return travel of the plate, which varies also depending on the place and dimensions of the tool.

The control device according to the invention aims at overcoming these drawbacks and is remarkable especially in that it comprises detecting means, connected with the pressing plate or unit for movement therewith and adapted to detect, during the travel of said plate in a given direction, the location of the tool and to deliver the corresponding information to a programme device or the like capable of controlling the different operational stages of said plate.

The device according to the invention allows thus to replace a purely manual positioning operation by an entirely automatic control giving a very high accuracy and avoiding any loss oftime.

According to another feature of the invention, the device includes a memory means connected to said detecting unit and capable of storing the data coming from said detecting means and to deliver them to said programme device.

The data stored in the memory may be used to control a subsequent motion of the plate which forms the unit. More particularly, such data may be utilized to control the return motion of said plate.

It will be especially appreciated that the device according to the invention allows not only an automatic positioning of the plate above any tool occupying any place on the work, but that it effects also an automatic return of the plate, the latter in all cases clearing the tool, whatever the nature and the place of said tool might be.

The invention will be better understood through the following description made with reference to the accompanying drawings, given only by way ofexample and wherein:

FIG. 1 shows in a schematic way a punching-machine, the pressing unit or plate of which is provided with a detecting device conformable to the invention, said plate being shown during its horizontal translatory motion toward the punching tool;

FlG. 2 represents the plate directly over the tool, that is at the end ofits horizontal translatory motion;

FIG. 3 shows the pressing plate seen in the direction indicated by the arrow A ofFlG. 1; and

FIG. 4 is a block diagram of a control device conformable to the invention.

The cutting press which forms the punching-machine schematically represented in the H65. 1 to 3 includes a stationary punching table 1 to carry the work 3 and a pressing unit or plate 2, movable in a horizontal translatory motion as well as in a vertical translatory motion. The piece 3 which forms the work to be punched is placed on a cutting counter-part 4 laid directly on the table 1. A cutting die inthe form ofa punching tool 5 is put on work 3, said tool 5 being driven vertically downward by the plate so as to punch the work 3. For this purpose, the pressing unit .or plate 2 performs a sequence of movement which includes a forward motion, [.e. a translatory motion from the left to the right following the arrow H, which brings it above the tool 5, a vertical downward motion following the arrow V during which it takes along the punching tool 5. an upward vertical motion following the arrow V, and then a return motion from the right to the left, following the arrow H, which brings it back to its starting position. During the back motion of the pressing plate, new work is substituted for the punched out work.

The pressing unit 2 is provided with a detecting device conformable to the invention, constituted by a radiation emitter in the form of a light source 6 equipped for instance with a (not represented) suitable optical system, so as to emit an appreciably linear light beam 7, and radiation receiver formed in the illustrated example by a photosensitive cell 8 (see FIG. 3), said light source 6 and said cell 8 being mounted on the front or leading end or face 2a of the plate (in the direction of the translation from left to right, [.e. of the initial motion of the plate). The source 6 and the cell 8 are placed in such a way that the light beam 7 is perpendicular to the direction of the motion H of the plate and that it is at an elevation slightly lower than the bottom face 2b of the latter.

When the pressing unit 2 moves from the left toward the right, as viewed in FIG. 1, the light beam '7 is interrupted as soon as it meets the left edge 5a of the punching tool 5, and remains interrupted until said beam passes beyond the right edge 5b of said tool, as viewed in FIG. 1.

FIG. 4 shows one embodiment of an electronic device for controlling the motions of the plate. According to the position of the plate 2 with respect to the tool 5, the cell 8 does or does not receive the light beams emitted by the light source 6 and transmits corresponding data. The data delivered by the cell 8 are transmitted, on the one hand, to a programme device or telecontrol panel 9 and, on the other hand, to a memory device 10. The programme device 9 controls the supply of a motor 11 actuating a pump 12, which in turn supplies the (not represented) hydraulic circuit of the machine; in addition, it supplies also the light source 6. Two relays or the like, and 13b, are also provided to allow a telecontrol of the machine by the operator.

When the plate 2 moves horizontally from the left to the right (FIG. 1), the light beam 7 is interrupted as soon as it meets the tool 5, Le. when the front of the plate arrives above said tool. The light beam 7 again reaches the cell 8 as soon as the leading portion of the plate 2 passes beyond the tool. The time during which the beam is interrupted is recorded by the memory 10 and the signal delivered by the cell 8 as soon as it again receives the light beam is used to control the stop of the plate 2, which is hence automatically positioned at the proper location. Of course, this stop control may also exert an immediate action or, on the contrary, a delayed action with the help of a time-lag device, depending on the position it is desired to give to the plate with respect to the tool, or again on the relative dimensions of the tool and of the pressing plate. lt may be seen that the plate is automatically stopped as soon as the cell 8 receives again the light beam, this stop control being independent from the dimensions of the tool and from its place on the punching table.

The information stored within the memory 10 is utilized to control, by means of the programme device 9, the return motion of the plate 2, this motion being thus function of the dimensions and of the position of the tool on the table, in such a way that the plate is entirely cleared under all operating conditions of the machine.

To avoid damaging the light source and the cell during the vertical downward motion of the plate, these units are mounted upon a collapsible part allowing to move them, for instance vertically on the front or leading face of the plate, as shown in FIG. 2.

The memory may be constituted by any known device, for example a magnetic core or tape memory. etc. Likewise. the programme device may also be otany known type.

lt is also possible to provide, on said plate or the like, several detecting systems, each for motion of said plate in a given direction. Thus, for instance, a detecting system could be used to control the vertical motion of said plate.

It will be readily appreciated that the invention allows to render the punching out or die-cutting operations entirely automatic, that it avoids the guesswork necessary in the manual methods, that it eliminates all danger of a faulty manipulation and that it extends to a maximum the lifetime of the plant.

Finally, it should be understood that the present invention is by no means limited to the described and represented embodiment which has been given only by way of example. Especially, said invention includes all means constituting technical equivalents to the described means as well as their combina tions, if the latter are carried out within the scope of the appended claims I claim:

1. In a cutting press, a stationary table to support work and a die thereon to be pressed therethrough, a pressing unit translatorily movable in horizontal and vertical directions to be placed above said die and then to exert upon the latter a vertical pressure, motor means for driving said pressing unit in translation, a detecting device carried directly by said pressing unit and comprising at least one radiation emitter for emitting a beam perpendicular to the direction of movement of said pressing unit and at least one radiation receiver for receiving the emitted beam and to deliver information signals, said die being situated in at least part of the path of movement described by said beam as the latter moves-with said pressing unit, and a programme device for receiving signals from said radiation receiver for controlling said motor means.

2. The combination according to claim 1, further compris ing a memory member connected to said detecting device and provided for operating said programme device.

3. The combination according to claim 1, wherein said radiation emitter and said radiation receiver consist 01 a light source and a photosensitive cell, respectively.

44 The combination according to claim 3, wherein the aforesaid light source and photo cell are mounted on a front leading end of said pressing unit in the direction of its motion and at an elevation lower than said unit whereby the light beam emitted by said source is interrupted when said pressing unit moves over said die with the latter extending to an elevation lower than said pressing unit but higher than said light beam 5. The combination according to claim 3, wherein a retractable support means carries the aforesaid light source and photo cell.