APPARATUS FOR PRINTING CONTINUOUS RUNS OF MATERIAL
United States Patent 3717722
Apparatus for printing continuous runs of material comprises rows of nozzles extending across the path of movement of the material. Colored printing fluid is supplied to each row of nozzles, each nozzle being controlled by a valve. A program control unit controls the pressure of fluid supplied to each row of nozzles and operation of the individual valves so as to maintain the quantity of fluid applied per unit area of the material substantially constant, irrespective of the speed of movement of the material. FIELD OF THE INVENTION The invention relates to apparatus for printing continuous runs of material. An object of the present invention is to provide apparatus for printing on continuous runs of material, in which the material can be fed at any desired speed independently of an operator, without variation in the appearance of the material and without the apparatus having to be adjusted by hand. SUMMARY OF THE INVENTION According to the present invention, there is provided in apparatus for printing a continuous run of material movable along a predetermined path, a plurality of rows of nozzles, each row extending transversely of said path, valve means for controlling each nozzle, a plurality of sources of colored printing fluid, means for feeding printing fluid from said sources to said rows of nozzles, regulator means for regulating the pressure of fluid fed to each row of nozzles, and program control means responsive to the speed of movement of the material along said path and controlling said value means and said regulator means to maintain the quantity of printing fluid applied per unit area of the material, substantially constant. Preferably the nozzle valves are pre-set by the control means according to the program, all the pre-set valves then being opened simultaneously, the pre-setting of the valves being cancelled at the end of the fluid application period. Between the individual rows of nozzles, it is desirable to fit supplementary rows in which the manner of application of the printing fluid differs from that of the main nozzles, these supplementary nozzles also being controlled by the program control means. Preferably, in addition to controlling the pressure of the printing fluid, the program control means controls the pulse length for the valve opening times and reciprocating and pivoting movement of the rows of nozzles. As the speed of the run of material increases, the pressure of the printing fluid is increased by the program control means, so that the amount of fluid applied per unit surface area is discharged in a shorter time. At the same time, the program control means varies the pulse length for the time during which the valves of individual nozzles are opened. The pressure of the printing fluid and the valve opening times are so programmed in relation to each other that, whatever be the speed of travel of the material, the amount of printing fluid applied is always correct and the printing fluid covers the correct length and width in the position determined by the design. The pulse length is therefore controlled independently of the color pulse train. In the program control means, recorded data for color control determine which valves of the individual rows of nozzles are to be opened; data for pulse-length control determine how long those valves shall remain open. Similarly, pressure-control data determines the pressure at which the printing fluid is sprayed onto the material. If, for example, compressed air or mains current be used for spraying the printing fluid, that particular form of supply is likewise program controlled to ensure that the appearance of the material remains the same, even if the speed of the run of material should vary. For printing very fine detail on fast-travelling material, the rows of nozzles can be pivoted under program control in such a way that the spray always stays at the same point on the material. For printing larger areas per nozzle, the rows of nozzles are both pivoted and moved transversely to the direction of travel of the material, all under program control, during which either the nozzle valves remain open or one pulse can be emitted for each position of the nozzle row, so that an individual nozzle is able to print four points. The control program can be stored on punched cards, perforated tapes, magnetic cards, magnetic tapes, magnetic drums, magnetic discs etc., for each individual color or on any other recording medium. Programming may also be carried out electronically by the use of, for example, magnetic tape recorders to which are fed the pulses from pick-ups employing color-sensitive heads for scanning patterns or originals. Patterns, drawings or originals, or color extracts can, if desired, also be scanned directly by a color-sensitive head, the derived values being converted into pulses in the control part of the equipment. If the resultant pattern is correct, the relevant data is recorded on the recording medium during the printing process. With this program recorded on an endless tape or the like, the pattern can be continuously printed. In the control program, data can be recorded for all the colors, according to the arrangement of the rows of nozzles, in addition to data for pattern repeat control, tint control, nozzle setting control, nature of nozzle, color pressure and pulse duration. Reading heads in the program control means for the various colors take the data from the program staggered in stages, according to the nozzle tube spacing. The programs for each color can also be prepared on individual magnetic tapes or the like, which can then be provided, according to the nozzle row spacings, with their own pattern repeat control data and nozzle-row setting control data. By automatic step-by-step change-over, controlled by a program of its own, from one program to another, the design or color combination can be changed in step with the run-through of the material, without waste or interruption. The data are picked up by the reading heads in the control unit or optically and are converted into pulses, which are amplified and then fed through a distributor in series or parallel to the nozzle valves concerned. When the speed of the material changes, the program also provides synchronous regulation of the color pressure and pulse length. When the data for all the colors have been recorded on the magnetic tape or the like, the reading heads in the control unit as well as the nozzle rows or groups of rows being constantly in the same position, the repeat is correct. Control of the valves of the individual nozzles in the rows or groups of rows may also be such that when patterns, originals and the like are being scanned, the pick-up pulses are fed in succession directly to the valves, after suitable amplification. Both when an original is being scanned for setting up a program and when there is direct control during the scanning of an original, lenses can be introduced for the enlargement or reduction. Enlargement can also be carried out by directly increasing the duration of the pulses. The pattern repeat at right angles to the direction of travel of the material is either allowed for in the program or arranged by group switching of the valves in the case of direct control from the original. The pattern repeat along the length of the material can be arranged as desired. By suitable switching, limited insertion of another program section or of control from an original can be made in the course of a program. Should the color points be very small and required to be arranged very close together, the nozzles for a single color can be distributed over several rows, through which the printing fluid flows in succession, the rows being so adjusted that the nozzles deposit the color points in the desired positions. The nozzle rows for the various colors can be arranged at any spacing and in any sequence desired. Likewise, the nozzle rows for one color can be disposed between the nozzle rows of the other colors. This distribution may also be necessary on account of the effects obtainable. The nozzles themselves can be electrostatic spray nozzles, single or multi-jet nozzles or atomizer nozzles and several rows of nozzles can be used for each color. All the rows of nozzles can be connected to an electric mains supply to deposit the printing fluid electrostatically. Suction can be applied to the run of material so as to draw the printing fluid onto the material or to draw the fluid through the material, in the case of materials having a fibrous nap or fibrous surface.
US Patent References:
IMAGE CONSTRUCTION SYSTEM USING MULTIPLE ARRAYS OF DROP GENERATORS
Taylor et al. - February 1971 - 3560641
IMAGE CONSTRUCTION SYSTEM WITH ARCUATELY SCANNING DROP GENERATORS
Taylor - February 1971 - 3564120
Film thickness control for electrostatic coating systems
Kock - September 1968 - 3402697
Methods and systems for reproducing color patterns in manufactured articles, particularly mosaic tile
Polevitzky - May 1965 - 3181987
Production of piled surfaces in pattern form
Meston - March 1939 - 2152077
IMAGE CONSTRUCTION SYSTEM USING MULTIPLE ARRAYS OF DROP GENERATORS
Taylor et al. - February 1971 - 3560641
IMAGE CONSTRUCTION SYSTEM WITH ARCUATELY SCANNING DROP GENERATORS
Taylor - February 1971 - 3564120
Film thickness control for electrostatic coating systems
Kock - September 1968 - 3402697
Methods and systems for reproducing color patterns in manufactured articles, particularly mosaic tile
Polevitzky - May 1965 - 3181987
Production of piled surfaces in pattern form
Meston - March 1939 - 2152077
Application Number:
05/138006
Publication Date:
02/20/1973
Filing Date:
04/27/1971
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
118/624, 347/40, 358/502, 118/630, 347/6
International Classes:
D06B11/00; D06B23/24; D06B23/00; H04N1/28; H04N1/46; H04N1/24
Field of Search:
178/5.2R,6.6R,5.4CD 118/624,630,631 346/74ES
US Patent References:
| 3247815 | Systems and methods for reproducing colored patterns in carpets and other manufactured articles | April 1966 | Polevitzky | |
| 3523158 | ELECTROGRAPHIC COLOR IMAGE PRINTING APPARATUS EMPLOYING TRIAD COLOR STRIP ZONE DEVELOPMENT | August 1970 | Zaphiroulos | |
| 3135828 | Apparatus for providing solid reproductions | June 1964 | Simjian |
Primary Examiner:
Britton, Howard W.
Claims:
What is claimed is
1. In apparatus for printing a continuous run of material movable along a predetermined path
2. Apparatus as claimed in claim 1 comprising
3. Apparatus as claimed in claim 1 wherein each said source of colored printing fluid comprises
4. Apparatus as claimed in claim 1 wherein the nozzles are multi-jet nozzles.
5. Apparatus as claimed in claim 1 wherein the nozzles are electrostatic spray nozzles.
6. Apparatus as claimed in claim 1, comprising
7. Apparatus as claimed in claim 1, wherein said program control means comprises
8. Apparatus as claimed in claim 1 wherein a number of said rows of nozzles are interconnected to define a group of rows, in each said group, the rows extending parallel and the nozzles in one row being staggered relative to the nozzles in an adjacent row.
9. Apparatus as claimed in claim 8 wherein the distance between the rows of nozzles in each said group corresponds to the pattern repeat length.
10. Apparatus as claimed in claim 1, wherein said program control means comprises
11. Apparatus as claimed in claim 10, wherein said camera produces pulses used to record a program.
1. In apparatus for printing a continuous run of material movable along a predetermined path
2. Apparatus as claimed in claim 1 comprising
3. Apparatus as claimed in claim 1 wherein each said source of colored printing fluid comprises
4. Apparatus as claimed in claim 1 wherein the nozzles are multi-jet nozzles.
5. Apparatus as claimed in claim 1 wherein the nozzles are electrostatic spray nozzles.
6. Apparatus as claimed in claim 1, comprising
7. Apparatus as claimed in claim 1, wherein said program control means comprises
8. Apparatus as claimed in claim 1 wherein a number of said rows of nozzles are interconnected to define a group of rows, in each said group, the rows extending parallel and the nozzles in one row being staggered relative to the nozzles in an adjacent row.
9. Apparatus as claimed in claim 8 wherein the distance between the rows of nozzles in each said group corresponds to the pattern repeat length.
10. Apparatus as claimed in claim 1, wherein said program control means comprises
11. Apparatus as claimed in claim 10, wherein said camera produces pulses used to record a program.
Description:
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a perspective view of apparatus in accordance with the invention;
FIG. 2 is a fragmentary plan of a modified form of the apparatus shown in FIG. 1;
FIG. 3 is a perspective view, to an enlarged scale, of part of a row of nozzles in the apparatus shown in FIG. 1;
FIG. 4 shows part of one form of magnetic tape for a control unit of apparatus; and
FIG. 5 shows part of another form of magnetic tape for the control unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, mounted in the machine frame 1 are two guide rollers 2 and 3, around which passes an endless, air-permeable, conveyor band 5. The roller 3 is driven by an electric motor 4 the speed of which can be regulated.
The top run of the conveyor band 5 lies over suction chambers 6, air being withdrawn from the chambers 6 by a pipe 7.
A continuous run of material 8, is drawn off a supply roll and carried by the conveyor band 5 in the direction of the arrow in FIG. 1. The material 8 passes below rows of nozzles 9 to 12, and 9a to 12a which extend transversely to the direction of movement of the material 8. The individual nozzles 13 in each row of nozzles are preceded by valves 13a (FIG. 3), which control the flow to the nozzles 13. The valves 13a are connected to a control unit 20 which so regulates the time during which the valves 13a are open that whenever the speed of travel of the material 8 changes, the same amount of color per unit surface area of material is applied at all times.
The rows of nozzles 9 to 12, and 9a to 12a are movable by control members 14 and 15 (FIG. 3). The control members 14 are operable to pivot each row of nozzles about its longitudinal axis, and the control members 15 are operable to reciprocate each row of nozzles along its longitudinal axis. The control members 14 and 15 are also connected to the control unit 20.
The rows of nozzles 9 to 12, and 9a to 12a are mounted in a frame, the height of which above the band 5 can be adjusted by means of positioning screws 19, for example.
Containers 16 for colored printing ink or other colored printing fluids are connected by feed and return pipes to the rows of nozzles 9 to 12 and 9a to 12a. Suitably the container 16 on the far left in FIG. 1 contains yellow colored fluid, while the next three containers in succession contain red, green and violet colored fluids, these being the colors needed for four-color printing. The container on the far right in FIG. 1 also contains yellow colored fluid. Inserted in the return pipe from each row of nozzles 9 to 12 and 9a to 12a is a pressure regulator 18 operated by a program in the control unit 20, the pressure regulators 18 acting to control the pressure of the fluid so that whenever the speed of travel of the material 8 changes, the same amount of fluid is applied per unit surface area at all times.
The program is recorded on, for example, a magnetic tape 22 fed into the control unit 20. The program recorded on the tape 22 determines the quantity, manner of application and point of application of the color and the design to be printed.
The nozzles 13 in each row are always offset from the nozzles in adjacent rows by one register. A tap 21, is fitted in every feed pipe, enabling the flow of colored fluid to be switched between pairs of feed pipes so that, for example, the row of nozzles 12a can be supplied with printing fluid while the flow to the row 12 is cut off. It becomes necessary to close the tap 21 when it is proposed to fit a different type of nozzle or when a fault develops in a row of nozzles. For the sake of clarity, the taps 21 in the pipes for the rows 9 to 11 and 9a to 11a have not been shown in FIG. 1.
If, for example, the row of nozzles 12a is associated with a separate container 16, it is possible to change over to another color combination while the row 12 is being overhauled, or the color itself may be changed.
The printing fluid is fed to the rows of nozzles 9 to 12 or 9a to 12a by pumps 17 via filtering means, excess printing fluid being led back through the return pipe into the appropriate container 16.
Between the adjacent rows of nozzles 9 to 12 and 9a to 12a, supplementary rows can be fitted, in which the nozzles differ from those in the rows 9 to 12 and 9a to 12a. These supplementary rows of nozzles are controlled by the control unit 20 according to the program.
In the modified arrangement shown in FIG. 2 groups of nozzle rows are provided, each group consisting of several rows such as 9, for example, connected in series and extending parallel to one another, only one such group being shown for the sake of simplicity. The distance a between the individual rows of nozzles, in each group is equal to the repeat length.
This arrangement of the rows of nozzles, enables the color points to be applied to the material 8 more closely together, because, clearly, the nozzles 13 in a number of rows in the group can be set closer together. In each group, the nozzles 13 in one row are staggered in relation to the nozzles in an adjacent row.
In individual rows of nozzles, nozzles of differing types can be fitted.
As can be seen from FIG. 3 of the drawings, by operation of the control members 14 and 15, a jet of printing fluid or cone of spray can be caused to track from a to b, from b to c, from c to d and from d to a whereby to cover the area thus enclosed.
In FIG. 4, magnetic tape 22 is shown to comprise eight tracks designated A to H. The tracks A to D are intended for the four colors, that is to say for yellow, red, green and violet.
Should it be desired to mix several colors, further data will also be recorded, such data being corrected for the distance between the rows of nozzles.
The track E controls the duration of spraying by the nozzles 13. When the speed of travel of the material 8 is increased, the program is necessarily speeded up likewise. The conveyor band 5 is so coupled to the control unit 20 that the correct relation is produced between the speed of the conveyor band 5 and that at which the program is advanced.
The track F controls the regulators 18 and hence the pressure of the printing fluid. For faster running, the individual data follow one another in closer succession. The pressure can be regulated non-linearly and adapted to the consistency of the printing fluid.
The track G regulates the pivoting of the rows of nozzles 9 to 12 and 9a to 12a. If program-controlled delay be used with the pressure control track, for example, it is possible to ensure that the jet of printing fluid follows the movement of the material 8 precisely and is therefore deposited accurately in dot form. The data in track G can be interrupted to alter the position of the rows of nozzles 9 to 12 or 9a to 12a. Then the rest of the material is sprayed. Thus, it is possible to print transverse lines, if the rows of nozzles 9 to 12 and 9a to 12a are pivoted so that the jets of printing fluid follow the motion of the material 8 and the rows of nozzles 9 to 12 and 9a to 12a carry out an axial movement.
The track H controls axial movement of the rows of nozzles 9 to 12 and 9a to 12a. When the open period of the valves 13a ends, a command cancelling the presetting of the valves 13a occurs in tracks A to D, which may be followed by a pause, after which follows the next train of data. This pause may be dispensed with, however.
Should more tracks be required, two tapes can be used, each with a synchronizing track.
In the program a further track can be used to effect a change to other programs.
The program may also be impressed on the recording vehicle in the form of computer codings. The appropriate machines for reading and control must then be installed.
FIG. 5 shows another form of magnetic tape 22 control unit in the device here proposed. Here the data used in FIG. 4 follow one another in the direction of travel of the tape 22.
The mode of operation of the apparatus described is as follows:
The material 8 is fed forward by the conveyor band 5 in the direction of the arrow until its leading edge lies below the row of nozzles 9 and is subject to suction from the suction chamber 6. The exposed part of the conveyor band 5 does not need to be shielded.
The program for printing the design has been inserted in the control unit 20. The control unit 20 also contains a supplementary program with which, for example, the apparatus can be started or stopped, the programs and colors can be changed without stopping and control can be changed over from a magnetic-tape to a camera and vice versa. For camera control, a color-sensitive picture-transmission camera, 23 (FIG. 1), if provided, this being connected to the control unit 20 and scans an appropriate colored pattern or color extracts.
At the commencement of printing, the supplementary program controls the design program pulses so that only the valves 13a of the nozzles 13 in row 9, below which the material 8 already lies, are opened.
The row of nozzles 9 then prints line by line; and when the material 8 arrives below the row of nozzles 10, the supplementary program releases the nozzles 13 and the pivotal and axial motions of the row 10 for pre-setting and for opening by pulses from the design program. The nozzles 13 in row 10 thereupon apply printing fluid according to track B next to the color according to track A.
Should the nozzle-row spacing of the colors not correspond to pattern repeat, the reading head in the control unit 20 scans in advance the data for the color according to track B, until the first line of color has arrived below the row 10. The data for the colors may also be recorded, on the magnetic tape 22 or the like, offset, so that they can be read by a line head. The data for the individual colors are then positioned side by side, displaced by as many lines as there are between the individual nozzle rows 9 to 12 and 9a to 12a. This displacement, which may be whatever is desired, can be variable. For colors corresponding to the tracks C and D, the process is repeated as described above. Upon shutting down, the closure of the valves 13a of the rows of nozzles takes place in step with the run-through of the material.
When changing to another design with the same colors, a second program 24 is inserted into the control unit 20 and is synchronized by the supplementary program; then this latter program changes over step from the design program pulses, in step with the run-through of the material 8, as with the starting-up of the rows of nozzles.
For changing nozzles -- from a jet nozzle to a spray nozzle, for example -- the design program cuts out the nozzle row 12 and brings the nozzle row 12a in instead, the tap 21 serving to re-direct the printing fluid. To be able to change over to other colors without a halt, a second row of nozzles 9a with a separate pump and container 16 is necessary for each color. By using several rows 9 and 9a, 10 and 10a, and so forth, it is possible to provide color change, nozzle change and fineness of design, and also of faster printing. When the nozzle rows are arranged with 9 spaced apart from 9a, 10 from 10a and so on by one register length, the material 8 can be printed twice as quickly.
The color pulse trains of one pattern are distributed by the program alternated line by line to the two rows of nozzles. Row 9 of the nozzles prints lines 1, 3 and 5 of the pattern, while the row 9a prints the lines 2, 4 and 6. It is always the last line alone which contains data for opening, shutting and cancelling, and this emits the opening, shutting and cancelling pulses for all the pre-set nozzle rows 9 to 12 and 9a to 12a. Thus the printing speed is doubled, trebled and so on, according to the number of rows of nozzles used.
An embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a perspective view of apparatus in accordance with the invention;
FIG. 2 is a fragmentary plan of a modified form of the apparatus shown in FIG. 1;
FIG. 3 is a perspective view, to an enlarged scale, of part of a row of nozzles in the apparatus shown in FIG. 1;
FIG. 4 shows part of one form of magnetic tape for a control unit of apparatus; and
FIG. 5 shows part of another form of magnetic tape for the control unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings, mounted in the machine frame 1 are two guide rollers 2 and 3, around which passes an endless, air-permeable, conveyor band 5. The roller 3 is driven by an electric motor 4 the speed of which can be regulated.
The top run of the conveyor band 5 lies over suction chambers 6, air being withdrawn from the chambers 6 by a pipe 7.
A continuous run of material 8, is drawn off a supply roll and carried by the conveyor band 5 in the direction of the arrow in FIG. 1. The material 8 passes below rows of nozzles 9 to 12, and 9a to 12a which extend transversely to the direction of movement of the material 8. The individual nozzles 13 in each row of nozzles are preceded by valves 13a (FIG. 3), which control the flow to the nozzles 13. The valves 13a are connected to a control unit 20 which so regulates the time during which the valves 13a are open that whenever the speed of travel of the material 8 changes, the same amount of color per unit surface area of material is applied at all times.
The rows of nozzles 9 to 12, and 9a to 12a are movable by control members 14 and 15 (FIG. 3). The control members 14 are operable to pivot each row of nozzles about its longitudinal axis, and the control members 15 are operable to reciprocate each row of nozzles along its longitudinal axis. The control members 14 and 15 are also connected to the control unit 20.
The rows of nozzles 9 to 12, and 9a to 12a are mounted in a frame, the height of which above the band 5 can be adjusted by means of positioning screws 19, for example.
Containers 16 for colored printing ink or other colored printing fluids are connected by feed and return pipes to the rows of nozzles 9 to 12 and 9a to 12a. Suitably the container 16 on the far left in FIG. 1 contains yellow colored fluid, while the next three containers in succession contain red, green and violet colored fluids, these being the colors needed for four-color printing. The container on the far right in FIG. 1 also contains yellow colored fluid. Inserted in the return pipe from each row of nozzles 9 to 12 and 9a to 12a is a pressure regulator 18 operated by a program in the control unit 20, the pressure regulators 18 acting to control the pressure of the fluid so that whenever the speed of travel of the material 8 changes, the same amount of fluid is applied per unit surface area at all times.
The program is recorded on, for example, a magnetic tape 22 fed into the control unit 20. The program recorded on the tape 22 determines the quantity, manner of application and point of application of the color and the design to be printed.
The nozzles 13 in each row are always offset from the nozzles in adjacent rows by one register. A tap 21, is fitted in every feed pipe, enabling the flow of colored fluid to be switched between pairs of feed pipes so that, for example, the row of nozzles 12a can be supplied with printing fluid while the flow to the row 12 is cut off. It becomes necessary to close the tap 21 when it is proposed to fit a different type of nozzle or when a fault develops in a row of nozzles. For the sake of clarity, the taps 21 in the pipes for the rows 9 to 11 and 9a to 11a have not been shown in FIG. 1.
If, for example, the row of nozzles 12a is associated with a separate container 16, it is possible to change over to another color combination while the row 12 is being overhauled, or the color itself may be changed.
The printing fluid is fed to the rows of nozzles 9 to 12 or 9a to 12a by pumps 17 via filtering means, excess printing fluid being led back through the return pipe into the appropriate container 16.
Between the adjacent rows of nozzles 9 to 12 and 9a to 12a, supplementary rows can be fitted, in which the nozzles differ from those in the rows 9 to 12 and 9a to 12a. These supplementary rows of nozzles are controlled by the control unit 20 according to the program.
In the modified arrangement shown in FIG. 2 groups of nozzle rows are provided, each group consisting of several rows such as 9, for example, connected in series and extending parallel to one another, only one such group being shown for the sake of simplicity. The distance a between the individual rows of nozzles, in each group is equal to the repeat length.
This arrangement of the rows of nozzles, enables the color points to be applied to the material 8 more closely together, because, clearly, the nozzles 13 in a number of rows in the group can be set closer together. In each group, the nozzles 13 in one row are staggered in relation to the nozzles in an adjacent row.
In individual rows of nozzles, nozzles of differing types can be fitted.
As can be seen from FIG. 3 of the drawings, by operation of the control members 14 and 15, a jet of printing fluid or cone of spray can be caused to track from a to b, from b to c, from c to d and from d to a whereby to cover the area thus enclosed.
In FIG. 4, magnetic tape 22 is shown to comprise eight tracks designated A to H. The tracks A to D are intended for the four colors, that is to say for yellow, red, green and violet.
Should it be desired to mix several colors, further data will also be recorded, such data being corrected for the distance between the rows of nozzles.
The track E controls the duration of spraying by the nozzles 13. When the speed of travel of the material 8 is increased, the program is necessarily speeded up likewise. The conveyor band 5 is so coupled to the control unit 20 that the correct relation is produced between the speed of the conveyor band 5 and that at which the program is advanced.
The track F controls the regulators 18 and hence the pressure of the printing fluid. For faster running, the individual data follow one another in closer succession. The pressure can be regulated non-linearly and adapted to the consistency of the printing fluid.
The track G regulates the pivoting of the rows of nozzles 9 to 12 and 9a to 12a. If program-controlled delay be used with the pressure control track, for example, it is possible to ensure that the jet of printing fluid follows the movement of the material 8 precisely and is therefore deposited accurately in dot form. The data in track G can be interrupted to alter the position of the rows of nozzles 9 to 12 or 9a to 12a. Then the rest of the material is sprayed. Thus, it is possible to print transverse lines, if the rows of nozzles 9 to 12 and 9a to 12a are pivoted so that the jets of printing fluid follow the motion of the material 8 and the rows of nozzles 9 to 12 and 9a to 12a carry out an axial movement.
The track H controls axial movement of the rows of nozzles 9 to 12 and 9a to 12a. When the open period of the valves 13a ends, a command cancelling the presetting of the valves 13a occurs in tracks A to D, which may be followed by a pause, after which follows the next train of data. This pause may be dispensed with, however.
Should more tracks be required, two tapes can be used, each with a synchronizing track.
In the program a further track can be used to effect a change to other programs.
The program may also be impressed on the recording vehicle in the form of computer codings. The appropriate machines for reading and control must then be installed.
FIG. 5 shows another form of magnetic tape 22 control unit in the device here proposed. Here the data used in FIG. 4 follow one another in the direction of travel of the tape 22.
The mode of operation of the apparatus described is as follows:
The material 8 is fed forward by the conveyor band 5 in the direction of the arrow until its leading edge lies below the row of nozzles 9 and is subject to suction from the suction chamber 6. The exposed part of the conveyor band 5 does not need to be shielded.
The program for printing the design has been inserted in the control unit 20. The control unit 20 also contains a supplementary program with which, for example, the apparatus can be started or stopped, the programs and colors can be changed without stopping and control can be changed over from a magnetic-tape to a camera and vice versa. For camera control, a color-sensitive picture-transmission camera, 23 (FIG. 1), if provided, this being connected to the control unit 20 and scans an appropriate colored pattern or color extracts.
At the commencement of printing, the supplementary program controls the design program pulses so that only the valves 13a of the nozzles 13 in row 9, below which the material 8 already lies, are opened.
The row of nozzles 9 then prints line by line; and when the material 8 arrives below the row of nozzles 10, the supplementary program releases the nozzles 13 and the pivotal and axial motions of the row 10 for pre-setting and for opening by pulses from the design program. The nozzles 13 in row 10 thereupon apply printing fluid according to track B next to the color according to track A.
Should the nozzle-row spacing of the colors not correspond to pattern repeat, the reading head in the control unit 20 scans in advance the data for the color according to track B, until the first line of color has arrived below the row 10. The data for the colors may also be recorded, on the magnetic tape 22 or the like, offset, so that they can be read by a line head. The data for the individual colors are then positioned side by side, displaced by as many lines as there are between the individual nozzle rows 9 to 12 and 9a to 12a. This displacement, which may be whatever is desired, can be variable. For colors corresponding to the tracks C and D, the process is repeated as described above. Upon shutting down, the closure of the valves 13a of the rows of nozzles takes place in step with the run-through of the material.
When changing to another design with the same colors, a second program 24 is inserted into the control unit 20 and is synchronized by the supplementary program; then this latter program changes over step from the design program pulses, in step with the run-through of the material 8, as with the starting-up of the rows of nozzles.
For changing nozzles -- from a jet nozzle to a spray nozzle, for example -- the design program cuts out the nozzle row 12 and brings the nozzle row 12a in instead, the tap 21 serving to re-direct the printing fluid. To be able to change over to other colors without a halt, a second row of nozzles 9a with a separate pump and container 16 is necessary for each color. By using several rows 9 and 9a, 10 and 10a, and so forth, it is possible to provide color change, nozzle change and fineness of design, and also of faster printing. When the nozzle rows are arranged with 9 spaced apart from 9a, 10 from 10a and so on by one register length, the material 8 can be printed twice as quickly.
The color pulse trains of one pattern are distributed by the program alternated line by line to the two rows of nozzles. Row 9 of the nozzles prints lines 1, 3 and 5 of the pattern, while the row 9a prints the lines 2, 4 and 6. It is always the last line alone which contains data for opening, shutting and cancelling, and this emits the opening, shutting and cancelling pulses for all the pre-set nozzle rows 9 to 12 and 9a to 12a. Thus the printing speed is doubled, trebled and so on, according to the number of rows of nozzles used.