DE8327911U1 - Pad printing machine - Google Patents

Description

Applicant: Stuttgart, 15 September 1983

Wilfried Philipp P 4413 R-ef Lenbachstrasse 8
/*! 7014 Kornwestheim

Representative :

Kohler - Schwindling - Späth
Patent attorneys
Hohentwielstrasse 41
7000 Stuttgart-1

Pad printing machine

The invention relates to a pad printing machine with a holder for a cliché, with an ink supply device having a hollow body, which rests on the cliché with a front surface of the hollow body, whereby ink is applied to the cliché from the inside of the hollow body, with a device for generating a relative displacement movement between the cliché and the hollow body, with a device for scraping off excess ink from the surface of the cliché, and with a pad which rests on

the inked cliché can be pressed and absorbs the ink from red recesses in the cliché and transfers it to an object to be printed.

In such a known machine, in which the hollow body forms a pot that is only open on one side, this pot sits on the cliché. The pot is moved over the cliché in a back and forth movement by means of a drive device. During the forward movement,

* ' the cliché is inked, whereby the ink inks both the recesses of the cliché, which is engraved in the manner of an intaglio printing plate, and the rest of the flat surface of the cliché, and during the return movement the hollow body leaves the area of the cliché and a squeegee arranged behind the hollow body and which can be moved with it strips off excess ink from the surface of the cliché, so that the ink only sits in the recesses of the cliché, from where it is removed by the pad. After the ink has been removed from the cliché, the pad is swiveled on an arm and then prints an object. The edge of the pot on this machine also has a certain

(') Squeegee effect, but is not able to completely cleanly squeegee the cliché without an additional squeegee. The edge of the pot of the known machine is made of a relatively soft material, namely plastic.

The number of printing processes that the known machine can carry out per hour is limited by the fact that the distances that the moving parts have to travel cannot be covered in an arbitrarily short time, because otherwise these parts would accelerate too strongly. In addition, if the speed of movement is too

f^ark, the possibility of the squeegee lifting off the surface of the cliché, because the more or less liquid or pasty ink on the surface of the cliché could cause the squeegee to float up, so that the cliché can no longer be cleaned cleanly

$ can be scraped off.

V The invention is based on the object of providing an i-machine of

\ ~ to create the type described above, whose working conditions

v J speed can be increased compared to the known hash i and which requires little maintenance.

I This object is achieved according to the invention in that

* the hollow body consists of hard material over at least part of the circumference of its front face and is precision machined

• and the surface of the also finely machined KIi-

; schees is adapted so that the hollow body with its entire

^ Front face rests against the cliché, and that a device

I device for pressing the front surface of the hollow body against the

Cliché with a predetermined contact pressure is provided such that the finely machined part of the front surface of the ;„) ) hollow body forms a scraping edge for the ink.

The advantage of the invention is that a separate doctor blade is no longer required, because the finely machined part of the front surface acts as a doctor blade itself. The pressing device can ensure that even at higher relative speeds between the cliché and the hollow body, the part of the front surface acting as a doctor blade cannot be lifted off. Because no special doctor blade is required, the additional space for the doctor blade is saved, and therefore the paths that the movable

Parts of the machine according to the invention have to travel are reduced compared to the known machine, and as a result the working speed of the machine, namely the number of printing processes per unit of time, can be increased without increasing the speed of movement.

The hard material can be machined with high precision and does not change its shape over a long period of time, even when printing inks are used that contain components that have an abrasive effect when exposed to them for a long time. The hollow body also does not damage the cliché, which can be made of any material and is preferably made of an engraved or etched steel plate. Hard metal or ceramic are particularly suitable as hard materials. The final shape of the front surface in the area of its contact with the cliché is best achieved by lapping with these hard materials.

If the cliché is flat, as described in the example, the front surface of the hollow body is also in one plane.

The front surface can have a cross-section that is similar to the cross-section of known doctor blades; in particular, it is advantageous if the front surface only rests on the cliché with a relatively shallow area, because this promotes reliable stripping of the ink.

For the sake of simplicity, it will be assumed below that the cliché moves and the hollow body is stationary; this also applies to the embodiment described later. If the front surface of the hollow body is only on

a part of its circumference is designed in such a way that it can act as a scraper edge or doctor blade, it is sufficient if this part of the front surface is located on the side of the hollow body on which the inked cliche is located after inking and doctoring by the said part of the front surface, from which the ink is then removed by the pad. In this case, the part of the front surface acting as a scraper edge ensures that the part of the '·' cliche that reaches under the area of the pad is cleanly doctored off. If the other parts of the front surface do not form such a perfect seal against the surface of the cliche, this only has the consequence that the area of the cliche lying beyond the hollow body from the point where the ink is removed from the cliche by the pad may be inked somewhat more strongly and color may build up there over time. This may then require more frequent cleaning at this point.

In order to largely prevent too much ink from building up on any side of the cliché, which could interrupt the workflow ( i due to cleaning measures, it is therefore preferably provided that the front surface of the hollow body is designed over its entire circumference in such a way that it can act as a scraper edge, whereby the leakage of ink can be prevented, if not completely, then at least to such an extent that cleaning of the cliché is only necessary at intervals of several hours. In particular, the hollow body consists of hard material in the area of its entire front surface or is coated with it.

The stripping of the paint in accordance with the well-known machine is also referred to here as doctoring·

In one embodiment of the invention, the device for pressing the hollow body onto the cliche is designed in such a way that the pressing force acts in the immediate vicinity of the contact surface between the cliche and the hollow body. This results in favorable _lever conditions which can easily prevent the hollow body from tipping over as a result of the frictional force between the hollow body and the cliche during the relative movement that occurs between the hollow body and the cliche.

Preferably, the contact pressure is adjustable in order to be able to adapt it to the respective requirements. The contact pressure depends on the size of the contact surface between the hollow body and the cliché. If this contact surface is reduced, for example because a hollow body with a smaller cross-section of its open side facing the cliché is used, then, all other conditions being equal, a lower contact pressure is required in order to ( ) achieve a consistent squeegee effect.

Because the front surface of the hollow body consists entirely or partially of a hard material, preferably the hard material mentioned above, it is important that the hollow body does not become jammed relative to the cliché. It is technically possible to mount the hollow body so rigidly and to guide the cliché, which is again assumed to be movable, in a guide so precisely that jamming cannot occur, such a construction is however very complex and susceptible to failure if handled inexpertly. Therefore, according to a design

form of the invention, the hollow body is bent in the vicinity of its contact surface with the cliché to prevent I tilting around a line running parallel to the cliché.

; and essentially transverse to the relative movement between the

cliché and the hollow body is guided so that it can pivot. This allows the front surface, which is pressed against the cliché by the :,; pressing device, to

% always (in a flat Klisohee) parallel to the surface

I , of the cliché and canting cannot occur . This design is very easy to manufacture . bar, because the management of the cliché can be very simple.

§ The described pivoting bearing is sufficient as a guide

&Bgr; near the surface of the cliché and the device

I for pressing, which in the simplest case is a screw

·) compression spring can be realized. The described, a

':i A guide that offers the possibility of swiveling is more practical.

i.\ according to one embodiment of the invention,

| ^J is such that it causes a displacement of the hollow body relative

I for guidance parallel to the relative movement between cliché and hollow body is largely prevented.

;") Preferably, the hollow body is also guided so as to be pivotable about an axis running in the direction of the relative movement.

According to one embodiment, the pivotable guide of the hollow body can be formed by a spherical bearing. In this case, a bead is provided on the outside of the hollow body, which forms part of a spherical surface or part of a round body similar to a sphere. In contrast, a construction according to another embodiment is often simpler, in which the pipe section near the surface of the cliché is supported by a bearing on its outside.

Ju-

engaging ring, this ring being supported on the hollow body with a spherical surface. If the hollow body has a round cross-section, which is also preferred for reasons of ease of manufacture, then this spherical surface of the ring can be part of a torus surface or be similar to such a surface.

The described bearings of the hollow body enable a pivoting movement about two pivot axes running parallel to the plane of the cliché, so that tilting of the hollow body in any direction is impossible. If tilting occurs in this way, very high forces could occur between the front surface of the hollow body and the cliché, which would pose a risk of damage. In addition, tilting in this way could lead to an unacceptably large gap being created between the cliché and the hollow body in areas of the front surface, through which ink could leak out in disruptive quantities.

In embodiments of the invention, the pivoting position of the hollow body can be adjustable and lockable.

In embodiments of the invention, the hollow body has a round cross-section, in other embodiments it has a rectangular cross-section. If the rectangular cross-section has sides of different lengths, it can be advantageous to have the longer side run transversely to the direction of the relative movement between the cliché and the hollow body, because then the hollow body is relatively short in the direction of movement and therefore the entire machine is relatively short.

In embodiments of the invention, the hollow body is made in one piece. This can make handling the hollow body easier.

In other embodiments of the invention, the hollow body is made up of several parts and has parts that can move relative to one another, that are in fluid-tight contact with one another or that are connected to one another in fluid-tight manner, and one part of the front face is provided on one part of the hollow body, and another part of the front face is provided on another part of the hollow body. This embodiment enables changes to the hollow body in the area of its front face, namely a shortening of the dimensions, without requiring the help of the manufacturer of the hard metal part or hard metal coating. In an emergency, if for some reason the length of a front face has to be shortened, it can simply be ground down.

Preferably, one of the movable parts of the hollow body has only a single, straight end face (. This makes it particularly easy to move this part on the other part of the hollow body.

It is advantageous to arrange a part of the hollow body that has only one straight front surface on the side of the hollow body facing the tampon. This ensures, as will be described later, that the cliché is scraped off cleanly in every case.

In one embodiment of the invention, the hollow body is divided into two parts, one of which is connected by a

I til·· trr... · ·

"- &idgr;&oacgr;

essentially flat plate, and the other part essentially has a wall running parallel to said plate, two side walls arranged at right angles to this, with their end faces resting against the plate, and a top wall running essentially at right angles to the wall and the side walls. This results in a simple construction which in particular also allows, in the embodiment described later with a guide sleeve, the guide sleeve to be removed at the same time as the hollow body is pulled out of the machine.

The surfaces of the parts that move relative to one another are precisely flat, in particular level, and lapped so that they connect to one another in a liquid-tight manner and prevent paint from escaping from the hollow body.

In another embodiment of the invention, instead of a movable plate which essentially takes up one entire side of the prismatic hollow body with a rectangular cross-section, the hollow body is closed in the area of this plate in its upper region, and a movable plate or generally a movable part which has the straight end face is arranged in the lower area of the hollow body so that it can move on it. In the first embodiment, however, the problem of liquid-tight sealing is generally easier to control.

Preferably, the individual parts of the hollow body are pressed against the cliché by a clamping device in order to

■1&iacgr;·

rapid relative movement between the cliché and the hollow body to reliably prevent the ink from escaping in the area of the front surface of the hollow body. In embodiments of the invention, the clamping device can be designed in such a way that each of the individual parts of the hollow body that are movable relative to one another is assigned its own clamping device, in particular a compression spring. This promotes a secure fit of the individual parts of the front surface on the cliché.

In embodiments of the invention, the parts of the hollow body are arranged in a particularly tubular guide piece, which in turn is mounted in the machine. This embodiment is particularly advantageous when using a hollow body with parts that can move relative to one another.

In one embodiment of the invention, at least one compression spring is provided between the guide piece and the hollow body. This causes the hollow body to rest on the side opposite the compression spring and thus a defined position of the hollow body in the guide piece. When using hollow bodies with parts that are movable relative to one another and rest against one another, the compression spring also causes the parts to rest sufficiently firmly against one another so that the joint between them is liquid-tight.

In one embodiment of the invention, it is provided that the guide piece is guided in its end region adjacent to the cliché about at least one axis running essentially parallel to the cliché and transverse to the relative movement between the cliché and the hollow body, and

that the hollow body in the guide piece is not arranged so that it can pivot relative to this axis. This makes it possible, in the manner described above, to create a possibility for the entire front surface of the hollow body to always sit on the plate surface, even if manufacturing tolerances occur, so that a perfect doctor blade effect is achieved.

In a further development of the invention, the parts of the hollow body are arranged in the guide piece so as to be movable about an axis running essentially parallel to the cliché and parallel to the relative movement between the cliché and the hollow body. This ensures that the front surface of the hollow body can be adjusted to the surface of the cliché in the other axis as well.

In one embodiment of the invention, a special adjustment device makes it possible to adjust and fix the pivoting position of the guide piece with respect to one pivot axis. With respect to the other pivoting position, the pivoting just described with respect to the other pivot axis is provided by a play between the hollow body and the guide piece.

In the various described embodiments of hollow bodies, the hollow body or its individual parts are so solid in the area of the front surface that they can be considered absolutely rigid. The front surface can be slightly rounded in embodiments of the invention. This is particularly advantageous if one of the parts of the hollow body can sit on the cliché at a different inclination, as is the case with the individual plate in the last embodiment.

4
• t · ·

13'

In the designs in which the hollow body has a rectangular cross-section, the end faces running parallel to the lamination direction do not have a squeegee function, but rather merely the function of sealing skirts, which are intended to prevent the ink from escaping. It seems possible to replace these sealing skirts with elastic parts without any loss of quality. It should also be remembered that the cliché in the area of these sealing skirts does not have any etching, but is completely smooth.

In one embodiment of the invention, deviating from the embodiment described below and in accordance with the known machine, it can be provided that the hollow body is mounted in a transport device that moves it relative to the cliché.

In another embodiment of the invention, which has already been mentioned several times, it is provided that the hollow body is arranged essentially immovably in the machine and a drive device that moves the cliché is provided.

This last-mentioned embodiment can be further developed in such a way that the cliché, or more precisely that part of the cliché that contains the inked and doctored engraving, is located in the "sweep" of the pad that it describes when printing on the object to be printed. When the ink is removed from the cliché, the pad therefore only partially carries out this vfeg, and after the ink has been removed and when the pad is no longer in contact with the cliché, the cliché is used for re-inking.

moved under the hollow body and the pad can now print on the object in question. This embodiment is particularly suitable for printing objects within a production line or transport line in a location that is difficult to reach. The cliché and the hollow body of the pad printing machine can be located above the production line, for example, and the pad is connected to a sufficiently long push rod that allows the pad to be moved downwards by a possibly considerable distance after the ink has been removed from the cliché in order to print on the object in a location where there would be no space for the entire pad printing machine. In particular, if the print to be applied is relatively small, i.e. only a few millimeters or a few centimeters in size, the pad can also be relatively small and light and can therefore be moved quickly even with simple construction effort, so that a large number of printing processes can be carried out per unit of time.

In one embodiment of the invention, the hollow body is only open on the front side facing the cliché. The hollow body is box-shaped or preferably cylindrical. To fill in the ink, it can be useful to tilt the entire machine so that the ink can be filled into the hollow body from above. The escape of the ink from the hollow body is made possible by the fact that the inks used for printing by pad printing contain a high proportion of volatile solvents, which are therefore able to create a sufficiently high gas pressure in the cavity inevitably formed by the ink flowing out of the hollow body, which enables further flow.

"15'

If such volatile solvents are not available, it seems likely that when the cliché is inked, sufficient air enters the hollow space of the hollow body from below to enable further flow of ink during the inking process.

In another embodiment of the invention , however, the hollow body is provided with an opening for introducing ink into the hollow body in addition to its open side facing the cliché. This opening can be located on a side wall of the hollow body, but preferably on

its side that is not clichéd. This opening can

\ be sealable to prevent air from entering larger

quantities that could affect the consistency of the paint due to evaporation of solvent. If the paint is to be removed from the hollow body without tipping the machine, it is possible to ensure by means of a suitable arrangement that the cliché can be moved far enough away from the hollow body by sideways movement that the paint can flow downwards. The flow of the paint can be facilitated by opening the opening mentioned, ~). Removing the paint from the hollow body without the risk of contamination is facilitated by a further device described below.

Since filling the hollow body is sufficient for several hours of machine operation or even for an entire shift (about 8 hours) with relatively small machine dimensions, as described for example in the example, it is not necessary to ensure that paint can be added to the hollow body while the machine is running. However, this can be

can be carried out continuously or in batches without difficulty through the additional opening mentioned above.

According to one embodiment of the invention, the cliché carrier that holds the cliché is at least twice as long as the length of the impression to be produced in the direction of the relative movement between the cliché and the hollow body. On the one hand, this enables the ink to be removed easily using the pad, according to the embodiment described above, and on the other hand, it also enables the machine to be further developed according to one embodiment of the invention in such a way that the cliché carrier is designed to hold a number of plates, such that one of the plates can be replaced while another of the plates completely closes off the hollow body, and that at least one of the plates is a cliché, i.e. has an engraving for receiving printing ink, and that the plates that are not designed as a cliché are finely machined on their side facing the hollow body in the manner of a cliché. The tops of the two plates abut one another without a step, i.e. they lie in the same plane at least in their contact area.

In the simplest case, this embodiment of the invention provides two plates, namely a cliché and a plate with the same surface quality as the cliché but not engraved. The non-engraved plate closes the hollow body during the times when the cliché is in the position in which the ink can be removed from the cliché by the pad. In this position of the cliché, the cliché can also be replaced with another cliché when the machine is at a standstill.

It goes without saying that instead of the non-engraved plate described, another cliché can also be used, especially if the machine is designed in such a way that the ink can be removed from both clichés using one or more pads. An engraved cliché is just as suitable for closing the hollow body during the replacement of a cliché as a non-engraved plate.

In one embodiment of the invention, one of the plates intended for insertion into the cliché carrier is designed in such a way that its surface facing the hollow body is tightly sealed against the front side of the hollow body, and that the plate has a recess through which the ink contained in the hollow body can be drained. A container can preferably be arranged on the plate in which the ink flowing out of the hollow body is collected, so that any risk of contamination of the machine is prevented. As mentioned above, it can be expedient to open a filling opening in the hollow body to allow the ink to flow out, in order to allow air to flow in.

The hollow body can have a cross-section that is so large, at least in its lower area, i.e. in the area of the front face of the hollow body, that it completely covers the engraving of the cliché. In a machine that produces a cliché of a specified maximum width, which is limited by the width of the cliché carrier, and a specified maximum length, which is limited by the possible displacement movement, a cross-section of the hollow body adapted to this maximum possible engraving must be provided in the area of its open front face.

However, it is possible to make the hollow body shorter in the direction of the relative movement between the hollow body and the cliché than the cliché itself, so that the cliché can never be located over its entire length within the cross-section of the front surface of the hollow body. Due to the relative movement, the cliché is nevertheless inked over its entire length and scraped off by the edge of the hollow body, which acts as a doctor blade.

( ■ However, it is also possible to make the dimensions of the hollow body smaller than the width of the engraved area, transverse to the relative movement between the cliché and the hollow body, if, according to an embodiment of the invention, it is provided that further hollow bodies are distributed across the width of the cliché, transverse to the direction of the relative movement between the cliché and the hollow body. This embodiment can be useful because a plurality of relatively small hollow bodies can be produced more easily and cheaply than a single large cooling body, and because these small hollow bodies can be produced in the appropriate number for a plurality of machines, which

■i~ ^ can be used by differing permissible widths of the cliché.

According to one embodiment of the invention, it may be expedient to arrange at least one of the hollow bodies offset in the direction of the relative movement between the hollow body and the cliché.

If several hollow bodies are planned, this creates the possibility of colouring a cliché with different colours at the same time. In general, it should not be

It is advisable to use different colors for adjacent hollow bodies that color the same areas of the cliché, because this results in a mixture of colors in this area. However, there may be applications where this mixture of colors is desired.

Further features and advantages of the invention will become apparent from the following description of embodiments of the invention with reference to the drawing, which shows details essential to the invention, and from the claims. The individual features can be implemented individually or in groups in any combination in an embodiment of the invention. They show

Fig. 1 a longitudinal section through an embodiment of a pad printing machine for applying markings on bodies to be printed with a high printing frequency,

Fig. 2 shows detail II in Fig. 1 on a larger scale,

Fig. 2a is an enlarged detail of Fig. 2,

Fig. 3 is a front view of the machine in the direction of arrow III in Fig. 1, partially broken away,

Fig. 4 is a section perpendicular to the plane of Fig. 1 through a paint removal device,

Fig. 5 a longitudinal section through a hollow body open only on one side,

Fig. 6 is a cross-section along line VI-VI in Fig. 5,

Fig. 7 a second embodiment,

Fig. 8 is a representation similar to Fig. 1 of a third embodiment,

(Fig. 9 the detail IX in Fig. 8.

Fig. 10 is a cross-section along the line X-X in Fig. 8.

The drawings show only the details necessary for an understanding of the invention.

The machine 1, which is a pad printing machine for quickly printing flat surfaces and preferably bodies with uneven surfaces using a pad 2 made of silicone rubber, has a base body or a machine frame 4 {■ on which the other parts of the machine are arranged. On the front of the machine 1 on the left in Fig. 1, the pad 2 is attached to a guide piece 6 projecting forwards over the rest of the frame 4 on a guide column 8 mounted in the guide piece so that it can be moved in the vertical direction. The guide column 8 is connected to the pad 2 via a holding plate 10 to which the lower end of a piston rod 12 of a pneumatic piston-cylinder unit 14 is attached. On the holding plate 10 there is also a switching rod 16 arranged parallel to the longitudinal direction of the piston-cylinder unit 14 and the guide column 8.

which carries height-adjustable switching cams 17 and 18, which interact with invisible band switches and are used to adjust the stroke length of the tampon 2.

Two mounting plates 19 and 20 are screwed to the side of the frame 1, parallel to one another and spaced apart, each of which carries in its lower flange area a plurality of upper guide rollers 21, all of which are arranged at the same height in one plane, and a plurality of lower guide rollers 22, which are arranged in a plane parallel to the plane just mentioned, with these upper and lower guide rollers 21 and 22 being arranged on the surfaces of the mounting plates 20 facing one another. A cliché holder 24 is slidably guided between the upper and lower guide rollers 21 and 22, with the cliché holder 24 being supported with its upper side 25 and its lower side 26 on the upper and lower guide rollers 21 and 22, respectively, and being guided by these in a precisely linear manner. The guide by the guide rollers is practically without any play. The cliché holder 24 has support brackets 28 against which a cliché 30 is supported from below, which is held in this position by clamping strips 32 which are screwed to the underside of the cliché holder 24 and engage the underside of the cliché 30. The clamping strips 32 leave space for the lower guide rollers 22.

Cliché 30 consists of a steel plate and has a completely flat and finely finished upper side, into which an engraving (not shown) is made, which can be produced either by engraving or by etching, in particular in a photochemical process. Cliché 30 is therefore an intaglio printing plate for pad printing.

In the view of Fig. 3 behind the cliche 30 and in the representation of Fig. 1 to the right of the cliche 30, a plate 40 is clamped into the cliche holder 24, the top 42 of which is completely flat and finely finished by lapping in exactly the same way as the cliche. This top 42 has no engraving. The plate 40 is pressed against the support shoulder 28 of the cliche holder 24 by clamping strips that can be removed and attached independently of the clamping strips 32, which are visible in Fig. 3. The cliche 30 and the plate 40 can thus be attached to and removed from the cliche holder 24 independently of one another.

The upper sides 35 of the cliché 30 and 42 of the plate 40 abut one another without any joints and lie exactly in the same plane. To ensure this, the support shoulder 28 of the cliché holder 24 is machined with sufficient precision.

The cliché holder 24 with the parts attached to it can be moved by a pneumatic piston-cylinder unit 46 which is attached to the frame 4 and whose piston ( ) rod 47 is connected via a connecting piece 48 to a connecting piece 49 which is attached to the rear of the cliché holder 24. The cliché holder 24 can be moved in the direction of the double arrow 50 by the piston-cylinder unit 46.

In the frame 4, a continuous bore 52 is provided which runs in a vertical direction and is slightly widened in its upper end region 54. In the lower end region of the bore 52, a ring 58 is inserted and fixed in a recess 56, the radially inward-pointing

Surface 60 is spherical in longitudinal section, see especially Fig. 2. A hollow body 64 is inserted into the bore 52, which has a circular cylindrical side wall 66, to which an end wall 68 is connected at the top, which is provided with a central threaded bore 70. A tube 72 is screwed into the threaded bore 70 from above, which projects beyond the top side 74 of the frame 4. The tube is hermetically sealed at its top by a removable screw plug 76.

In its lower end region, the side wall 66 of the hollow body 64 has a collar 80 which projects radially outwards relative to its remaining outer surface 78, the outer surface 82 of which forms a circular cylindrical surface. The upper side 83 of the collar 80 forms a bearing surface on which a spring 84 designed as a compression spring, namely a helical compression spring, is supported with its lower end. The upper end of the spring 84 is supported on a shoulder 86 which is provided on a quick-release fastener 88 inserted into the expanded region 54, which has a knurled wheel 90 at its upper end for easier handling and is held in the frame 4 with the aid of projections 92 in the manner of a jigsaw fastener. The quick-release fastener 88 is drilled lengthwise, and the diameter of this bore 94 is larger than the outer diameter of the tube 72, so that the quick-release fastener 88 does not hinder any lateral movements of the tube 72 and therefore corresponding movements of the hollow body 64.

In the exemplary embodiment, it is assumed that the spring 84 is designed in such a way that it transmits the desired contact pressure to the collar 80 without any further adjustment.

'24*

If an adjustment of the contact pressure is to be provided, this can be done without difficulty by providing a screw that essentially matches the dimensions of the quick-release fastener 88, with the area 54 of the hole 52 then being designed as a threaded hole. The contact pressure of the spring 84 can then be adjusted by screwing in this screw, which replaces the quick-release fastener 88, a sufficient distance.

Towards the lower end, specifically below the collar 80, the wall thickness of the hollow body 64 decreases so that the front surface 96 of the hollow body 64 resting on the cliché 30 (see Figure 2a) forms a plane. The front surface is, like the top of the cliché 30 and the plate 42, flat and lapped with high precision. In order for the front surface 96 to have a high degree of dimensional stability and abrasion resistance, the hollow body 94 is made of a hard material in the immediate vicinity of the front surface 96. In the example, the lower end region of the hollow body 64 is formed by a ring 98 made of hard material, in the example /* of hard metal, which has the front surface 96, whereas the rest of the hollow body 64 is made of steel. The ring 98 is made by sintering and connected to the rest of the hollow body 64 by brazing.

Instead of using a separate ring 98 made of hard material, the hollow body 64 could also be made of steel in its lowermost area, to which hard metal or hard metal oxides have been applied by means of a suitable coating process, in particular the plasma spray process, whereby the required smoothness of the end face 96 is also subsequently produced by fine grinding and lapping.

■ ■ ■ ·

Inside the hollow body 66 there is printing ink 110, which has been filled through the tube 72. Since the lower end face 96 of the hollow body is very close to the top of the cliché 30 and is also pressed against it by the compression spring 84, the ink cannot flow out. The printing ink contains a relatively high proportion of volatile solvents.

The distance between the upper side 83 of the collar 80 and the lower * end face 96 is approximately half the diameter of the hollow body 66 in the region of its lower end face 96.

Below the pad 2 and in a plane below the cliché holder 24 together with the clamping strips 32 attached to it there is an object 115 to be printed, which is only indicated in the area of its upper side to be printed.

The machine shown works as follows:

The piston-cylinder unit 46 moves the cliché holder / 24 forward, in Fig. 1 alo to the left, until the plate 40 has assumed exactly the position that the cliché 30 assumes in Fig. 1. During this displacement process, the front surface 96 of the hard metal ring 98 strips off excess ink from the top of the cliché 30, so that only ink remains in the recesses on the top of the cliché. This inked area of the cliché is now located below the pad 2. Compressed air is now supplied to the piston-cylinder unit 14, which moves the pad 2 downwards and presses it onto the cliché. The pad 2 is then lifted off the cliché again.

and takes the printing ink from the recessed areas of the cliché. The cliché holder 24 is now moved back into the position shown in Fig. 1 by the piston-cylinder unit 46. The pad 2 is then moved downwards by the piston-cylinder unit 14 and pressed onto the object 113, whereby the object is printed. The pad 2 is then raised back into the position shown in Fig. 1. Another object to be printed is brought to the place where the object 115 is located in Fig. 1, and the machine movement sequence just described is repeated. The position that the cliché 30 assumes when it is ready for the ink to be removed by the pad 2 is shown in Fig. 1 with dot-dash lines. During the time in which the cliché 30 is in the area below the pad 2, the plate 40 lies with its surface close to the front side 96 of the hollow body 64 and prevents the ink from escaping. Since the upper sides of the cliché 30 and the plate 40 fit together exactly even in the area of their contact point, practically no printing ink can escape from the interior of the hollow body 64, unless the portion of the printing ink that is located within the recesses of the cliché and is to be removed from the pad 2.

The tampon 2 consists of a silicone rubber and is elastically deformable. The contact pressure with which the tampon 2 is pressed against the top of the cliché 30 is expediently dimensioned such that the tampon is only deformed to such an extent and lies flat against the cliché only in such a large area as is necessary to receive the

-So

engraved area of the cliché. The engraved area of the cliché is expediently spaced from the inner boundary of the front surface on all sides in the position of the cliché 30 shown in Fig. 1. This ensures that small traces of ink that can accumulate on the edge of the area of the cliché 30 and the plate 40 that is covered by the front surface 96 during the sliding movement of the cliché holder 24 are not picked up by the pad 2. In the area located within these edge areas, however, the cliché is wiped off completely cleanly.

The hollow body 64 is held in position by the ring 58, the spherical inner surface of which allows a slight pivoting movement of the collar 80 about axes running parallel to the top of the cliché, and by the compression spring 84. Since the compression spring 84 acts on the collar 80 in an area just above the compression side, there is a favorable lever arm which strives to prevent any tipping of the hollow body 64 as a result of frictional forces which occur during the sliding movement of the cliché carrier 24. It should be noted, however, that the printing ink used has a certain lubricating and thus friction-reducing effect. Due to the described pivotability in the area of the ring 58 and due to the constant pressure by the spring 84, the front surface 96 always lies tightly against the top of the cliché 30 or the top of the plate 40. This creates a seal on all sides. The pressure with which the lower face 96 rests on the top of the cliché 30 and the plate 40 is also the same in the entire peripheral area of the

Front surface 96 is almost the same size. This prevents uneven wear, especially on the top of the cliché. The service life of the clichés is therefore very long. The front surface 96 practically does not wear out.

Because of the good sealing in the area of the lower front surface 96, the printing ink 110 does not have to be removed from the machine when it is stopped, even if it is idle over the weekend. Printing can begin immediately when work starts again without any time-consuming cleaning work.

If the cliché 30 is to be replaced, it is only necessary to move the cliché carrier 24 forwards from the position shown in Fig. 1 to the position marked with dot-dash lines, without lowering the pad 2 onto the cliché 2. The cliché 30 is then replaced. During this time, the plate 40 prevents printing ink 110 from escaping from the interior of the hollow body 66.

If the printing ink 110 is to be removed from the hollow body 66, for example in order to be able to print a different color, the auxiliary device 120 shown in Fig. 4 is used.

The auxiliary device 120 is shown in a section perpendicular to the plane of the drawing in Fig. 1. It has a plate 125 in its upper area, the dimensions of which correspond exactly to the dimensions of the cliché 30 and the plate 40.

•23 ·'

The plate 125 is finely machined, particularly on its upper surface. To remove the ink 110, the cliché 30 is exchanged for the auxiliary device 120 in the manner described above. After the exchange, the cliché carrier 24 is moved back into the position shown in Fig. 1 and a hole 128 arranged in and passing through the plate 125 is now connected to the interior of the hollow body 64. The locking screw 76 is now loosened and because air can now flow into the hollow body 64

(can, the printing ink 110 flows into a container 130 provided below the plate 125 on the auxiliary device 120. The top of the plate 125 is finely machined like that of the plate 40 and then, when the auxiliary device 120 is mounted, merges seamlessly into the top of the plate 40. It goes without saying that the container 130 can also be chosen to be larger than in the exemplary embodiment. After the printing ink 110 has been drained, it can be expedient to rinse the inside of the hollow body 64 through the tube 72 with solvent in order to clean it. During these operations, the hollow body 64 remains in place. The auxiliary device 120 can then be pushed back against the

/'* Cliche 30 or another cliche 30 can be exchanged, and new printing ink is filled into the hollow body 64, and the work can then be continued with the machine.

Fig. 5 shows a hollow body 164 that differs from the design example in Fig. 1. It is completely closed in the area of its upper end wall 168, and a rod 173 made of solid material is therefore screwed into the end wall 168 instead of the tube 72. This rod 173, like the tube 172, also serves, among other things, to insert the hollow body

and to remove the hollow body for any maintenance tasks.

In a machine that uses the hollow body 164, the entire machine is conveniently arranged to be pivotable so that it can be rotated so that the front surface 96 of the hollow body 164 faces upwards. In this position, the hollow body 164 is then pulled downwards out of the machine with the aid of the rod 173 (after loosening the quick-release fastener 83).

( ) ne removed when printing ink is to be filled into or removed from the hollow body. In this embodiment, the printing ink is thus filled into the hollow body 164 while the hollow body 164 is outside the machine; then the hollow body is reinserted into the machine from below. The removal of printing ink from the hollow body 164 when changing colors is done in the same way, but in the reverse order: after the machine has been turned so that the front surface 96 faces upwards, the hollow body 164 is removed downwards from the machine so that there is no risk of the machine being damaged by

/\ the paint is dirty. The hollow body is then poured out, cleaned and given new paint and put back into the machine.

The cross-section of the hollow bodies 64 and 164 is, as shown in Fig. 6, circular-cylindrical.

A construction that differs from Fig. 5 is shown in Fig. 7. Here, the contact pressure of the spring 84 can be adjusted in the manner just described by means of a screw 188 that replaces the closure piece 88. The upper end of the

Spring 84 is supported by an axial ball bearing 190 on screw 188 so that this can be easily adjusted. A rod 173 is not provided here. Hollow body 264 is only open in the area of its front surface 96.

The drive for the tampon 2 does not necessarily have to have a stroke limitation by means of adjusting rings 17 and 18. It is also possible to supply the piston-cylinder unit 14 with a pressure medium, in particular compressed air, which generates a constant pressure during the downward movement of the tampon 2 within the piston-cylinder unit 14. The stroke movement of the tampon 2 is then limited by the fact that the tampon 2 comes into contact on the one hand with the upper side of the cliché 30 and on the other hand with the upper side of the object 115 to be printed and deforms in the desired manner and to the desired extent according to the selected pressure and the elastic properties of the silicone rubber.

A great advantage of the machine shown is that the plate carrier 24 can be moved between the position in which

■> the cliche 30 is inked, and the position in &igr;

which the ink is removed from the cliché 30 by the pad, has only a very short displacement path, among other things because an additional doctor blade is not required. Due to this small displacement path and because the front surface 96 of the hollow body 64 or 164 always lies close to the top of the cliché carrier 24 even at high displacement speeds, the printing machine can achieve a very high printing speed. In a realized embodiment in which the drive of the cliché holder 24 and the pad 2

Although it is not yet at the highest possible speed, 7,000 prints per hour have been achieved. It is assumed that 10,000 prints per hour or more can be achieved without difficulty. In contrast, known machines have so far only been able to print about 2,500 prints per hour.

In the embodiment , the hollow body 64 and 164 has an inner diameter of 25 mm and a clear height of 90 mm. The width of the lower end face 96 is expediently 0.1 to 0.5 mm - in the example 0.3 mm. The ring 98 consists of a so-called hard metal, namely a sintered material produced using hard metallic materials, such as is also used for cutting tools, for example.

The displacement path of the cliché holder 24 is 50 mm. The other dimensions can be found in the scaled drawing.

The machine 200 shown in Figures 8 to 10 differs from the machine according to Figures 1 to 7 in the area of the hollow body, designated here with the reference number 202. The hollow body 202 is made up of several parts that are not firmly connected to one another. On its side facing the tampon 2, it has a flat plate 204 that tapers at its lower band area and here carries a hard metal strip 206 that tapers further downwards, the lower end face of which, like the end face 96 of the ring 98 in Figure 2a, forms a stripping edge. The stripping edge formed by the hard metal strip 206 runs straight. The hollow body 202 also has a

Cross-section U-shaped part 210, delimited by right-angled corners, which has a wall 212 parallel to the plate 204, at the lateral ends of which, in Fig. 8, therefore behind and in front of the drawing plane, side walls 214 and 216 extend at right angles to the wall 212 and to the plate 204. The front faces of the side walls 214 and 216 3 are precisely flat and lapped, and the surface areas of the plate 204 that are adjacent to these front faces are also precisely flat and lapped, so that when the surface areas mentioned are pressed against one another, they form a seal against the leakage of liquid. In cross-section, the flat plate 204 and the part 210 form a rectangle, the short side of which runs in the direction of the displacement movement of the cliché 30, and the long side of which runs transversely thereto. A stripping edge is also provided at the lower end area of the part 210, namely in the area of its side walls 214 and 216 and the wall 212, which is formed by a hard metal part 218 that corresponds to the cross-section of the part 210 and is therefore essentially U-shaped.

/ The part 210 also has an upper wall 219 which runs at right angles to the wall 212 and the side walls 214 and 216 and into which a threaded bore 70 is made which runs vertically and into which, as in the embodiment according to Fig., a tube 72 is screwed from above, the puncture of which corresponds to that of the tube 7? in Fig. 1.

The plate 204 and the part 210 are inserted into a guide sleeve, whose inner cross section corresponds essentially to the outer cross section of the hollow body 202. The guide sleeve is supported by a plate 222 and by a

Cross-section U-shaped part 224, which are screwed together so that they form the guide sleeve with a rectangular inner cross-section. The part 224 has a wall 231 and side walls 232 and 233.

Four blind holes 229 are made in the outside of the plate 204, in which compression springs 230 are arranged, which are supported on the inside of the part 222 of the guide sleeve and thereby press the plate 204 so firmly against the side walls 214 and 216 that the liquid seal described above is achieved. At the same time, these springs hold the outer surface of the wall 212 in contact with the inner surface of the wall 231 of the tail 224 adjacent to this wall 212. There is then a very slight gap between the outer surface of the plate 204 and the inner surface of the plate 222, which also makes it easier to insert the hollow body into the guide sleeve. In addition, because of this gap, the contact force with which the plate 204 is pressed against the side surfaces 214 and 216 is determined solely by the compression springs 230.

The guide sleeve 222, 224 projects upwards beyond the upper wall 219 of the hollow body. An upper wall 234 is also provided on the part 224, which connects the three walls of the part 224 to one another. The upper wall 234 has an upwardly projecting projection 236, which is drilled through to allow the pipe 72 to pass through at a distance on all sides, and which is rectangular in its external cross section, although this cross section is smaller than the external cross section of the guide sleeve in the sectional plane of Fig. 10. A compensating ring 240, which is also rectangular in plan view, is placed on this projection 236. The

It # · IIIII
• * · ti

Inner dimensions of the compensation ring 240 are larger than the

External dimensions of the projection 236. In the compensation ring 240

are a front maggot robber 242 and a rear maggot

screw 244 is provided through which the compensation ring 240

f can be fixed on the projection 236, depending

% depending on which of the grub screws 242 and 244 is screwed in further, in a position shifted further forwards or further backwards, in Fig. 8 thus in a position shifted to the right or left relative to the entire guide sleeve 222, 224. A fastening element 250 with a support surface 252 rests on the top of the compensating ring 240. The compensating ring 240 can also be fixed to the projection 246 at a selectable height by means of the grub screws 242 and 244.

The guide sleeve 222, 224 is located within a recess 260 of the machine frame designated here by the reference numeral 270.

The plate 222 and the wall 231 of the part 224 have, at their lower end section, curved projections 272 which project outwards and are supported on the adjacent surface of the recess 260'. The axis of curvature of the projections 272 runs horizontally and perpendicular to the plane of the drawing in Fig. 8 and 9. The width of the recess 260 measured horizontally in Fig. 8 is constant over the entire height of this recess 260 and is so large that the projections 272 lie just against the inner surfaces of the recess 260. Due to the projections 272 and because the outer surfaces of the guide sleeve 222, 224 pointing forwards and backwards, i.e. to the left and right in Fig. 8, are set back relative to the adjacent surfaces of the recess 260, the pivot position is

the entire guide sleeve within the recess 260 can be adjusted using the grub screws 242 and 244. The guide sleeve can, for example, run completely parallel to the longitudinal direction of the recess 260, or can be tilted slightly forwards or backwards. This is possible because the length of the clamping ring 240 visible in Fig. 8 (measured in the horizontal direction) is exactly as large as the distance between the surfaces 273 and 274 of the recess 260 measured in the same direction, and because the compensating ring 240 cannot therefore move forwards or backwards within the recess 260.

Two compression springs 276 and 277 are supported on the underside of the upper wall 234 of the guide sleeve, of which the two compression springs 276, of which only one is visible in Fig. 8, press on the upper face of the flat plate 204, and the two compression springs 277 press on the upper face of the upper wall 220 of the part 210. Since the compression springs 276 and 277 are supported via the upper wall 234 and the compensating ring 240 on the fastening part 250 and via this on the machine housing 270, the compression springs 276 and 277 thus strive to press the flat plate 204 and the part 210 independently of one another against the top of the cliché 30. The frictional forces between the flat plate 204 and the part 210 as well as between the hollow body and the guide sleeve are so small that the pressing of these parts against the cliché 30 is not hindered.

The fastening part 250 also has a rectangular cross-section and is fixed in the machine frame 270 by means of bolts, which are here fastened by screws 280 with a cut-off

Head and therefore allow the locking piece 250 to be removed after a rotary movement. After the locking piece has been removed, the guide sleeve and the hollow body are pulled out on the tube 72. The relatively low friction forces between the flat plate 204 and the part 210 are sufficient to hold the part 204 in the arrangement when it is removed.

The outer surfaces of the side walls 214 and 216 are a short distance from the adjacent surfaces of the side walls 232 and 235 of the part 224, a few tenths of a millimeter, in the example 0.2 mm. The hollow body 202 can therefore move within the guide sleeve 222, 224 perpendicular to the plane of the drawing in Fig. 8 and can in particular perform tilting movements. Therefore, due to the springs 276, without any other adjustment devices being provided, the lower stripping edge or front surface of the hard metal part 206 always lies completely on the cliché surface and is held in this position by the compression springs 276. In this direction, which is determined by the play between the side walls 214 and the adjacent walls of the guide sleeve, the part 210 of the hollow body can also adjust itself by the force of the compression springs 277. Because the compression springs 277 in the embodiment of Fig. 8 have a line of action that lies behind the front face of the hard metal part 218 visible in Fig. 8 and therefore in any case do not strive to keep the lower front face of the hard metal 218 in the area of the side walls 216 completely in contact with the cliché 30, in the machine shown, the inclination of the hollow body about a horizontal and perpendicular to the plane of the drawing in Fig. 8 pivot axis is controlled by the

adjusting ring 240 and the grub screws 242 and 246 in cooperation with the projections 272.

The setting process is carried out in such a way that the worker who sets up the machine uses a light gap to assess whether the lower face of the hard metal part is resting on the plate surface in its entire area, i.e. in the area of the side walls 216 and the wall 212, or whether this face is in the area of the side walls

/ 214 and 216, particularly in the vicinity of the flat plate 204» is lifted off the cliché (in this case the guide sleeve must be swivelled slightly anti-clockwise in the illustration in Fig. 8), or whether the front surface of the hard metal part 218 is lifted off the cliché in the area of the wall 212 (in this case the guide sleeve must be swivelled slightly clockwise in the illustration in Fig. 8 by adjusting the grub screws 242 and 244 accordingly. This adjustment of the grub screws takes place in the embodiment shown, in which adjustment in the installed state is not yet possible, after removing the fastening part 250 and pulling the hollow body together with the guide sleeve out of the

V. Machine housing 270.

Even if the worker does not adjust the part 224 precisely by adjusting the compensation ring 240 when setting up the machine, which would result in the lower face of the hard metal part 218 not being in contact with the cliché surface over its entire length and therefore ink being able to leak out here, the lower face of the plate 204 would still be in contact with the cliché surface over its entire length and this contact over the entire length is

•99

regardless of the inclination of the hollow body caused by the ' adjusting ring. Even if the machine

is not perfectly furnished, the cliché is

: Movement forward through the lower face of the plate

204 is perfectly doctored and the quality of the prints produced is therefore not affected by errors in setting up the machine.

': Machine 200 differs from machine 1 in

) by using a different cliché. Namely, instead of cliché 30 and plate 40, a

: Cliche 30' is used, whose length is the sum of the lengths

s- of the cliché 30 and the plate 40. This means

It is not necessary to have an absolutely smooth transition between the surfaces of the cliché 30 and the

. plate 40. During normal operation of the machine, the hard metal parts 206 and 218 always slide on the absolutely flat and stepless surface of the cliche 30*. If the cliche 30' is to be replaced, it is first moved to the left until it assumes the position shown in Fig. 1 with dot-dash lines, then a fastening screw 290 is loosened, which connects the cliche carrier to the connecting piece 48, and the entire cliche carrier is now moved further forward, i.e. to the left in Fig. 8. In doing so, a plate 292, which is connected to the cliche 30' and whose top is machined with high precision, is placed under the hollow body 202 and seals it while the cliche 30' is being replaced.

The guide sleeve is made of hard-anodized aluminum. The front plate 204 and part 210 are made of steel hardened by nitriding.

■■« ·

It. .

, Ol · ■

• 140

The machines shown are particularly suitable as built-in printing units in production lines, packaging lines, filling plants and assembly lines with high running speeds. They are suitable for printing on completely flat objects as well as on objects with irregular shapes. The maintenance work to be carried out on the printing machines takes very little time; it is practically limited to refilling ink from time to time, for example at the end of a shift, or, if necessary, replacing a cliché. These activities can be carried out by semi-skilled personnel.

The machines according to the invention are particularly advantageous because many uneven parts have to be labeled and dated on automatic production lines, whereby coding or other imprints are required. These tasks can be carried out without difficulty by the machines according to the invention and allow these imprints to be applied even where this was previously not possible due to the lack of a suitable machine.

Claims (1)

PeA-naprüche 1. Pad printing machine with a holder for a cliche, with an ink supply device having a hollow body, which rests on the cliche with a front surface of the hollow body, whereby ink is applied to the cliche from the inside of the cliche, with a device for generating a relative displacement movement between the cliche and the hollow body, with a device for scraping off excess ink from the surface of the cliche, and with a pad which can be pressed onto the inked cliche and absorbs the ink from the depressions of the cliche and transfers it to an object to be printed, characterized in that the hollow body (64, 164, 264, 202) consists of hard material at least on part of the circumference of its front surface (96) and is finely machined and adapted to the surface of the likewise finely machined cliche (30), that the hollow body (64, 164, 264, 202) rests with its entire front surface against the cliché (30), and that a device (84, 88, 188, 276, 277) is provided for pressing the front surface of the hollow body against the cliché with a predetermined contact force, such that the finely machined part of the front surface (96) of the hollow body forms a stripping edge for the ink. t · ··*■ ·· «ti » fr · r*% 2. Machine according to claim 1, characterized in that the hard material is hard metal or ceramic 13t. 3. Machine according to one of the preceding claims, characterized in that the device (84, 88, 188) for pressing the hollow body (64, 164, 264) onto the cliché (30) is designed in such a way that the pressing force acts in the immediate vicinity of the contact surface between the cliché (30) and the hollow body (64, 164, 264). 4. Machine according to one of the preceding claims, characterized in that a device (188) for adjusting the contact pressure is provided. 5. Machine according to one of the preceding claims, characterized in that the hollow body (64, 164, 264) is guided in the vicinity of its contact surface with the cliché (30) to pivot about at least one axis running essentially parallel to the relative movement between the cliché and the hollow body in order to prevent tilting. 6. Machine according to claim 5, characterized in that the hollow body is guided so as to be pivotable about two axes running essentially parallel to the relative movement between the cliché and the hollow body. 7· Machine according to claim 6, characterized in that the pivotable guide is formed by a spherical bearing. &thgr;. Machine according to claim 6, characterized in that the pivotable bearing is formed by an annular support bearing with a spherical inner surface (60). 9. Machine according to one of claims 5 to 8, characterized in that the pivoting position of the hollow body \s pers (202) with respect to at least one axis \ is cash. 10. Machine according to one of the preceding claims, characterized in that the hollow body (64, 164, 264) has a round cross-section. 11. Machine according to one of the preceding claims, characterized in that the hollow body (64, 164, 264) is in one piece. 12. Machine according to one of claims 1 to 10, characterized in that the hollow body (202) against each other ( movable, fluid-tight fitting or parts (204, 210) connected to one another in a liquid-tight manner, such that a part of the end face is provided on one part (204) of the hollow body and another part of the end face is provided on another part (210) of the hollow body. 13. Machine according to claim 12, characterized in that at least one of the parts (204, 210) of the hollow body (202) has only a single rectilinear end face intended for contact with the cliché (30 ¹ ). 14· Machine according to claim 13» characterized in that the hollow body is divided into two parts (204» 210), of which one part (204) is formed by a substantially flat plate, and the other part (210) has essentially a wall (212) running parallel to said plate (204), two side walls (214» 216) arranged at right angles to this and resting with their end faces on the plate (204) and a ceiling wall (219) running essentially at right angles to the wall and the side walls. 15· Washing machine according to claim 13 or 14, characterized in that the part (204) of the hollow body (202) closest to the tampon (2) is one with only a single straight end face. 16. Machine according to one of claims 12 to 15» characterized characterized in that the individual parts (204, 210) of the hollow body are pressed against the cliché (30 ¹ ) by a clamping device. / , 17· Machine according to one of claims 12 to 16, characterized characterized in that each of the parts (204, 210) of the hollow body is assigned its own tensioning device, in particular compression spring (276, 277). 18. Machine according to one of claims 12 to 17, characterized in that the parts (204, 210) of the hollow body are arranged in a particularly tubular guide piece (222, 224). 19· Machine according to claim 18, characterized in that at least one compression spring (230) is provided between the guide piece (222, 224) and the hollow body (202). 20. Machine according to one of claims 18 or 19, characterized in that the guide piece (222, 224) is guided in its end region adjacent to the cliché (30 ¹ ) so as to be pivotable about at least one axis running essentially parallel to the cliché and transverse to the relative movement between the cliché and the hollow body, and that the hollow body (202) is arranged in the guide piece so as not to be pivotable relative to this axis. 211. Machine according to claim 20, characterized in that the parts (204, 210) of the hollow body (202) are arranged in the guide piece (222, 224) to be movable about an axis running substantially parallel to the cliché (30 ¹ ) and parallel to the relative movement between the cliché and the hollow body. ,22. Machine according to claim 20 or 21, characterized in that the guide piece (222, 224) is supported laterally in its lower end region on the wall of a recess (274) of the machine receiving the guide piece and that at a distance from the support at least one adjustable stop (240) is provided which is supported on the guide piece and on the wall of the recess (260). 23« Machine according to one of the preceding claims, characterized in that the hollow body is mounted in a transport device that moves it relative to the cliché. • · · »lit · · ■ > I · 24· Machine according to one of claims 1 to 22, characterized in that the hollow body (64·, 164, 264, 202) is arranged essentially immovably in the machine and a drive device (46) is provided which moves the cliché (30, 30·). 25* Machine according to claim 24, characterized in that the cliché (30, 30') is in the inked and doctored state in the tfeg of the tampon (2) which the latter describes when printing the object to be printed. 26. Machine according to one of the preceding claims, characterized in that the hollow body (164. 264) is only open on its end face facing the cliché (30). 27· Machine according to one of claims 1 to 25, characterized in that the hollow body (64» 202) has, in addition to its open side facing the cliché, an opening for introducing ink into the hollow body. 28. Machine according to one of the preceding claims, characterized in that a cliché carrier (24) is provided which, in the direction of the relative movement between the cliché (30, 30') and the hollow body (64, 164, 264), is at least twice as long as the length of the impression to be produced. 29· Machine according to claim 28, characterized in that the cliché carrier (24) is designed to hold a number of Plates are designed in such a way that one of the plates (cliché 30, 30') can be exchanged, while another of the plates (40) completely closes off the hollow body, that at least one of the plates is a cliché (30, 30'), and that the plate or plates not forming a cliché are finely machined on their side (42) facing the hollow body (64·, 164, 264, 202) in the manner of a cliché.
C 30. Machine according to claim 28 or 29, characterized in that one of the plates (125) intended for insertion into the cliché carrier is designed in such a way that its surface facing the hollow body is in tight contact with the front side of the hollow body and that the plate (125) has a recess (128) through which printing ink (110) contained in the hollow body (64) can be drained. 31. Machine according to one of the preceding claims, characterized in that transversely to the direction of the t Relative movement between the cliché and the hollow Several hollow bodies are arranged distributed across the width of the cliché. 32. Machine according to claim 31, characterized in that at least one of the hollow bodies is arranged offset in relation to at least one other hollow body in the direction of the relative movement.