DE2218627A1 - Control circuit for the supply of printing ink via pressure nozzles in circular stencils on machines for printing materials in tape form, in particular textiles - Google Patents

Description

PATENT ADVOCATE

DiPL.-PHYS. DR. WALTHER JUNIUS 3 Hanover

ABBESTRASSE 20 TELEPHONE 83 45 30

April 16, 1972 My file: 2096 Dr. Y / J-

ELITEX - Zavody textilniho strojirenstvi, generalni reditelstvi, L i b e r e c (Czechoslovakia)

Control circuit for the supply of printing ink via printing nozzles in circular stencils on machines for printing Materials in tape form, in particular textiles

The present invention relates to a control circuit for supplying printing ink via printing nozzles in circular stencils on machines for printing materials in tape form, in particular textiles.

So far, various control loops have been used on machines for printing flat V / aren tapes deliver a constant amount of paint per second to the interior of stencils by means of pumps, the maximum color level inside the stencil with the help of a float, an interrupted jet

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is checked by a photocell or switch contacts which is the electrical conductivity of the printing ink and the like. In these systems, the paint fills the inner part of the circular stencil Atmospheric pressure. The one to push the paint through necessary through grid-shaped openings in the template However, the final overpressure is relatively high and depends on the speed of the printing, the viscosity of the Color, the size of the grid-shaped openings and the coveted saturation of the printed materials depending on " These pressures are achieved with the help of various abrasive, elastic blades or cylindrical doctor blades, which are pressed mechanically or electromagnetically against the inner surface of the template.

The disadvantage of these control loops is a high level of wear and tear on the pump rotors as a result of the interrupted Running, especially with rotors made of rubber, and in the difficulty of obtaining a necessary color print in front of the grid-shaped openings of the template for the changing operating conditions. An increase the hydrostatic color pressure, which is given by the height of the color level in the stencil, is achieved through the hydrodynamic effect of a colored border wedge under the Sinreibeelement, but it is exchangeable must be, ZcB. with elastic squeegees Increase of their contact pressure and with circular squeegees mainly by changing the diameter of the squeegee, which is first procedure for one; rush imperfectly resolved and at zv; ei :: en procedure is practically unsolvable.

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The introduction of a color printing nozzle according to another patent, which enables uninterrupted operation of the pump, the drive of which is connected to a printing machine, therefore represents a considerable advance. An ink container is used here, which is arranged in the junction of its pressure hose of the pump above the level of the nozzle, from which an excess amount of printing ink flows back into the container. The upper container may be closed and the excess ink flows into the container via a throttle valve .

The disadvantage of this system is the need to complete the hydrostatic control Pressure in the paint nozzle when the upper paint container is open by changing the height of the mirror surface in the container or with the upper container closed in the need to complete the Regulation of the throttle valve depending on the changing operating conditions, the control systems, which strive to regulate the color pressure in the nozzle are very complicated, demanding in terms of space and cleaning of the whole circle in contact with the paint is very costly.

The present invention avoids these disadvantages. The object of the invention is to provide a control loop for the supply of printing ink, by means of which the on a surface unit of the printed material with consideration on the different sizes of the

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the amount of printing ink delivered by circular stencils can be regulated »

The main characteristic of the invention is that a variable speed motor driving a pump has a variator SO as well as a clutch is assigned which with Is controlled using a hand switch.

Another characteristic is that the clutch apart from the manual switch by a limit switch depending on the pressure of the color in a pressure nozzle is controlled, the limit switch being stored in a plug which closes one side of the pressure nozzle is.

According to a further characteristic, it is particularly advantageous if the between the control motor and the driven Pump arranged variator is provided with a planetary outlet reduction gear «

The essence of the invention and further advantages and features of the subject matter of the invention are based on the following an embodiment shown schematically in the drawing 'explained in more detail. Show it:

Figure 1 is a diagram of a basic version of the control circuit according to the invention,

Figure 2 is a diagram of a further embodiment of the control circuit according to the invention,

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Figure 5 is a diagram of a print nozzle arrangement in a Circle template on a flat printing machine in side view,

FIG. 4 shows a partial section through a pressure nozzle end which is closed by means of a plug and is provided with a pressure indicator,

FIG. 5 shows a partial section through a pressure nozzle end as in FIG. 4, but with the difference that it is provided with a limit switch of a coupling,

Figure 6 is a front view of an embodiment and arrangement of the control loop according to the invention on a cylinder printing machine with a larger number of circular templates,

FIG. 7 shows a side view of the arrangement according to FIG. 6,

FIG. 8 is a side view of the arrangement of pressure nozzles in circular stencils on a cylinder printing machine.

As FIG. 1 shows, the basic design of a control circuit according to the invention is a storage container for printing ink 1, a suction pipe 2 penetrating into this container 1, a pump 3 and a pressure pipe 4 formed by means of a quick release connection 6 with a forming the subject of another invention Pressure nozzle 7 is connected «As Figure 3 shows, the mouth of the pressure nozzle 7 is on the inner wall a circular template 8 tightly on »in the pressure pipe 4 is

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a junction is provided, on the end of which a removable auxiliary pressure accumulator 5 (Figure 1) is arranged, with the help of which a readjustment of the pressure is carried out in the event that the permeable pattern surfaces are particularly unevenly distributed on the circumference of the circular template 8 and a regulation by other means is insufficient. At the other end of the pressure nozzle 7 there is a stopper 9 (FIG. 4) which closes the pressure nozzle 7 from one side. In the stopper 9, a piston Io made of elastic, sealing material, for example a cup-shaped sleeve, is mounted on a piston rod 12. With this piston rod 12, the piston Io is arranged displaceably in a recess 22 of the pressure nozzle 7 in the direction of its longitudinal axis against the action of a pressure spring 11 attached to the piston rod 12, depending on the pressure of the paint in the pressure nozzle 7 .

A vent opening 23 is provided in the plug 9. When the piston Io is disengaged under the influence of the color in the pressure nozzle 7, the piston rod 12 is also disengaged, at the end of which outside the pressure nozzle 7 a pressure indicator 12 ″, for example in the form of a colored ball or some other shape, is arranged, which is in the disengaged position draws attention to the achievement of the operating pressure of the paint in the nozzle 7. The pump j3 (FIG. 1) is connected by a variator 19 and a gear train 18 to a control motor 17, which drives the pump 5 via a coupling 16, e.g. the electromagnetic one Multi-disc clutch or clutch of any other kind, forms, Z \: r Ivrr ^ wV.ir y of a large control range

7 -

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i ¹ J 3 d 5 I / SJ u y S

the exit speed it is possible to equip the variator 19 with a planetary exit gear 2o, whereby a regulation of the values from almost zero to maximum values is achieved. The clutch 16 is controlled via an electrical circuit 14 of a power source 15 with the aid of a manual switch '21

The control circuit according to the invention shown in Figure 2 differs from the control circuit shown in Figure 1 in that the clutch ΐβ apart from the Haridsehalter 21, which in this case represents a main switch that puts the control circuit according to the invention into operation, still by another, in the plug 9 mounted limit switch 13 is controlled, the shaft, which controls the switching on and off of this limit switch 13 depending on the pressure of the ink in the pressure nozzle 7, is also formed here by the piston rod 12 already used in the basic version according to Figure 1 · The limit switch 13 is connected to the coupling l6 and controls it via the electrical circuit 14. Also in this embodiment, the control circuit according to the invention is formed by the paint reservoir 1, suction pipe 2 and pump 3, which on the one hand with the suction pipe 2 and on the other hand with the pressure pipe 4 is connected »This is in turn with the help of the quick clamping connection 6 with d he pressure nozzle 7 connected. The mouth of the pressure nozzle 7 lies tightly on the inner wall of the circular template 8. In the pressure pipe k a junction is provided on the end of the

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detachable auxiliary pressure accumulator 5 is arranged, by means of which a readjustment of the pressure is carried out when the permeable pattern surfaces are distributed particularly unevenly on the circumference of the circular template 8 and regulation by other means is inadequate. At the other end of the pressure cell 7 (FIG. 5) there is the stopper 9, which closes the pressure nozzle 7 from one side. In the stopper 9, the limit switch 13 is mounted, the shaft of which is formed by the piston rod 12 carrying the piston Io made of elastic sealing material, e.g. a cuff The action of the compression spring 11 placed on the piston rod 12 is arranged to be displaceable in the pressure nozzle 7 as a function of the pressure of the ink. The vent opening 25 is located in the plug 9. When the piston Io is in the disengaged position, due to the action of the paint in the pressure nozzle 7, the piston rod 12 forming the shaft of the limit switch 1J> opens the contacts of the electrical circuit 14, which, for example, acts as an electromagnetic multi-disc clutch or clutch other type trained clutch 16 controls. This is connected to the drive of the pump 5, which consists of the regulating motor 17 connected to the variator 19 via the gear transmission 18, the variator 19 being provided with the planetary outlet countershaft 2o for the purpose of a large regulating range of the outlet revolutions, whereby a regulation of the values of almost zero up to maximum values is achieved.

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Figures J> and 8 serve to explain in more detail the mutual arrangement of the printing nozzles 7 and circular stencils 8 on printing machines on which the control circuit according to the invention is used.

In Figure 3, circular templates 8 are illustrated, inner half whose printing nozzles 7 are housed The circular stencils 8 are rotatable on a flat printing machine arranged on which a printing pad 27 is driven by means of two cylinders 28, 28 ', with an upper run of the printing substrate 27 being a printed Material 29 carries which is carried along by the printing pad 27 under the circular stencils 8 and as a result its rotary movement is continuously printed. »The printing nozzles 7 are stationary within the circular stencils 8 arranged in a position shown in Figure 3. More details of the arrangement, e.g. the storage of the circular stencils 8, their drive, guidance of the printed material 29, drive of the cylinders 28, 28 'and thus also the printing underlay 27, Connection of the pressure nozzles 7 with the control circuit according to the Invention relate, are therefore not shown in detail, because it is only a diagram of an exemplary arrangement of the device on which the control loop according to the invention can be used.

The arrangement of pressure nozzles 7 and circular templates 8 on the circumference of a central cylinder is similar in FIG of a cylinder printing machine shows where

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rather the printed material 29 via a guide cylinder 31 is fed under the circular templates 8. As a result of their rotating movement, these print the material 29, the pressure nozzles 7 always remaining in the position shown in FIG. 8 in this case as well. From a closer illustration of closer details, such as the drive of the central cylinder 3o, storage of the circular templates 8 and connection of the pressure nozzles 7 with the control circuit according to the invention also omitted here for the same reasons as in FIG. 3.

In FIGS. 6 and 7, the arrangement example is a larger one Number of control loops according to the invention illustrated where by the electric motor 17 via a gear train 24 and individual gear transmission l8 a larger number of variators 19 is driven, the are arranged vertically one above the other in several rows on a hollow column 25, this hollow column 25 being the Gear housing forms with an oil bath.

The individual variators I9 can be arranged horizontally Planet exit pre-located 2o be provided, which allow a large control range and over Couplings l6 are also connected to horizontally arranged pumps 3. The regulation of individual variators 19 takes place either by means of the handwheels 26, or it can also be remotely controlled with the aid of remote control (not shown) Servo motors must be carried out. This embodiment is particularly advantageous in that by the

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Arrangement according to this embodiment, the built-up area of the machine with the shortest possible supply of printing ink the reservoir 1 to the circular template 8 is minimal. The individual pumps 2 are connected with the aid of pressure pipes 4 connected to the associated printing nozzles 7, which in circular stencils 8 on the printing machine, as in Figure 7 shown, are stored.

The control circuit according to the invention works as follows;

When a printing process is started, the printing nozzle 7 is first filled with printing ink in that the electrical circuit 14 of the clutch 16 is closed by means of the manual switch 21 (FIGS. 1, 2), which drives the motor via the variator 19 t or planetary outlet countershaft 2o and pump J. 17 turns on, whereby the pump 5 is put into operation. Through it, printing ink is sucked in from the container 1 with the help of the suction pipe 2 and conveyed through the pressure pipe 4 into the pressure nozzle 7 9 in the surrounding atmosphere. As soon as the printing ink reaches the piston Io, the overpressure acting on the piston is increased, which results in a displacement of the piston Io and the piston rod 12 against the action of the compression spring 11 , in the figure with dashed lines is pushed out position.

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The pressure indicator 12 ″ arranged outside the pressure nozzle 7 draws the operator's attention to the color pressure in the pressure nozzle 7, whereupon the operator disengages the clutch 16 with the aid of the manual switch 21. This interrupts the electrical circuit 1h of the clutch 16, which also drives the electric motor 17 separates the variator 19 or planetary outlet countershaft from the pump, so that it stops conveying the printing ink into the printing nozzle 7. In this way, the procedure is progressive for all printing nozzles 7 individually (see, for example, the arrangement according to FIGS. 6 and 7) the insertion of the printing nozzles 7 with printing ink is complete, the actual printing process can begin.

When the printing process is started, a not shown, the printing substrate 27 (Figure 3) and circular stencils 8 driving electric motor switched on, which with the control motor 17 driving the pump 3 (Figure 1, 2) cooperates. When the ink is removed from the printing nozzle 7, there is a pressure drop in the printing ink on the piston lo, so that this together with the piston rod 12 as a result of the action of the compression spring returns to the starting position. The operator switches the hand switch 21 on again, whereby the clutch 16 is engaged and the pump 3 is connected to the drive, so that the pump 3 in turn further printing ink is conveyed from the reservoir 1 into the printing nozzle 7.

In the event that the permeable surface of the circular template "

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is very small and, moreover, irregular, becomes a Part of the printing ink delivered through the pressure pipe 4 into the pressure nozzle 7 into the auxiliary pressure accumulator 5 promoted. From here, the printing ink reaches the printing nozzle 7 at intervals in which there is this pressure nozzle 7 is that wall part of the circular stencils 8, which is permeable. This creates a Pressure pulsation of the printing ink in the tube 4 and nozzle 7 is avoided and the course of the printing process is uniform secured, whose important factor is, among other things, a constant pressure of the printing ink "

In the embodiment according to FIG. 2, the puncture runs of the control loop according to the invention in a similar manner. When the printing process is started, for the time being the pressure nozzle 7 filled with printing ink that with the help of the manual switch 21, which in this Execution forms the main switch of the device according to the invention, the electrical circuit 14 of the clutch l6 is closed o This clutch 16 switches the control motor 17 via the variator 19, if necessary via the planetary output countershaft 2ο with the pump J5 a, which is thus put into operation and through the suction pipe 2 printing ink from the reservoir 1 sucked in and conveyed through the pressure pipe 4 into the nozzle 7. At the same time escapes from this displacement space Air through the recess 22 provided at the end of the pressure nozzle 7 (FIG. 4) and around the piston Io and through the vent opening 23 located in the plug 9 into the surrounding atmosphere. As soon as the Printing ink reaches the piston Io, the excess pressure acting on the piston Io is increased so that the

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Piston Io is displaced together with the piston rod, which forms the shaft of the limit switch 1J> and which switches it off, against the pressure of the spring 11, as a result of the cited effect. This interrupts the electrical circuit l4 of the clutch 16, which separates the electric motor 17 with the variator 19 or planetary outlet countershaft 2o from the pump j5, so that it stops conveying the printing ink into the printing nozzle 7. This disengagement of the drive from the pump 3 occurs in this embodiment in the event that the pressure of the printing ink is higher than its operating pressure during the printing process and this is the case separately for each pressure cell 7, e.g. in the arrangement according to FIGS. 6 and 7 .

When the printing process is started, an electric motor (not shown) driving the printing substrate 27 and circular stencils 8 is switched on, which works synchronously with the regulating motor 17 driving the pump J>. When the ink is withdrawn from the pressure nozzle 7, the pressure of the ink on the piston lo drops, so that this, together with the piston rod 12 forming the shaft of the limit switch ± J>, returns to the starting position as a result of the action of the compression spring 11. Thus, the contacts of the limit switch 1J5 are switched on, the electrical circuit lh is closed, the clutch 16 is engaged again and the pump 3 is connected to the drive, so that it continues to convey printing ink from the reservoir 1 into the printing nozzle 7.

In the case that the permeable surface of the circular template

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8 is very small and, moreover, irregular, a portion of the pressure tube 4 is delivered into the pressure nozzle 7 Ink conveyed into the accumulator 5. From here, the printing ink reaches the printing nozzle 7 in Intervals in which that part of the wall of the circular template 8 is located under this nozzle 7, which is permeable is ο This avoids pressure pulsation of the printing ink in the pipe 4 and nozzle 7 and ensures uniformity the course of the printing process secured, the important factor of which is, among other things, a constant pressure of the Printing color is

After the printing process has ended, the printing ink is removed from the printing nozzle 7 by reversing the pump 5 and pressure pipe 4 pumped back into the Parbvorratsbehaiter 1.

The control circuit according to the invention is cleaned by connecting the suction pipe 2 to a washing liquid container, not shown, as well as the Pressure pipe 4 with the help of a pump-around hose, also not shown, for the washing liquid circulation pump J5 takes care of it. The cleaning of the pressure nozzle 7 takes place with the aid of a not shown Washing device which is the subject of another invention β

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Claims (1)

Claims 1.) Control circuit for the supply of printing ink via printing nozzles onto the inner wall of circular stencils on machines for printing on materials in tape form, in particular textiles, with an ink reservoir and includes a supply line in which a pump driven by a variable speed motor is switched on and the control motor is synchronized with the drive source of a printing substrate and circular stencils, characterized, that the control motor (17) driving the pump (3) a variator (19) * and also a clutch (16) is assigned, which with the help of a manual switch (21) is controlled. 2. Control loop according to claim 1,
characterized, that the clutch (16) apart from the manual switch (21) by a limit switch (15) depending on the Printing of the printing ink in a printing nozzle (7) is controlled, the limit switch (15) in one, one Side of the pressure nozzle (7) closing plug (9) is mounted. ; 5. Control loop according to claim 1,
characterized by that at least two variators (19) and at least two clutches (16) are assigned to the regulating motor (y) driving at least two pumps (3). - 17 -209851 / 06E6 4. Control circuit according to Claims 1 and 2, characterized in that that the variator (19) is provided with a planetary outlet reduction gear (2o). 5 control circuit according to claims 1 to 3, characterized, that in a pressure pipe (4) an auxiliary pressure accumulator (5) is arranged, 6. Control loop according to claims 1 and 3. » characterized, that in the, the end of the pressure nozzle (7) closing Plug (9) engages a piston rod (12), on one of which, in a recess (22) of the pressure nozzle (7) engaging end a sealing piston (lo) together with the piston rod (12) in the direction of their Longitudinal axis against the pressure of a spring (11) encompassing the piston rod and at the other end of the Piston rod (12) a pressure indicator (12 ') is arranged. 7. Control loop according to claims 2, 3, 6, characterized, that the piston rod (12) in the plug (9) of the pressure nozzle (7) forms a shaft of the limit switch (13) which controls the clutch (l6). 2Ü9851 / Ü6 56 Blank page