EP0707959B1 - Screen-printing process and device for carrying out said method - Google Patents

Description

The invention relates to a method and an apparatus for Printing of single objects using the screen printing process.

It is known from EP-PS 0121486, methods and devices of this type using program-controlled NC single drives to execute. This prior publication discloses especially the relative movements that occur during printing interacting parts, in particular object, Screen printing stencil and squeegee, run, and how the resulting Movements out of a common coordinate system assigned motion components. This is especially true for the printing of objects, their to be printed Section in cross section from the shape of an arc deviates with a single central axis.

Furthermore, a screen printing machine is known from DE-OS 3730409, where a number of separate, coordinated controllable drive motors for the movement of the individual organs, especially the holder for the object to be printed and the portafilter are provided. The only bracket is attached to the front of the machine so it can be moved back and forth. This machine has low productivity on, since only one bracket is provided, which also over the Pressure range up to a feed conveyor on the one and a discharge conveyor on the other side is movable. As a result, after the end of the last printing process and possibly drying Object must first be removed from the holder before then move the bracket back to its original position can be used to record the next object there. Especially for devices with multiple printing stations for application For example, a print image that consists of several Colors exist, the low productivity of this device especially clear.

Accordingly, the invention is based inter alia on the object program controlled screen printing machines of the above described type so that a greater throughput can be achieved without the number of Printing stations would have to be enlarged. It is also sought that to achieve good print quality Relative movements of those interacting during the printing process Parts, in particular between screen printing stencil, squeegee and object to be printed can be coordinated precisely.

To achieve this object, the invention proposes that at least two brackets and a special one for each bracket Means of transport are provided and each means of transport driven by a special NC motor for a bracket becomes. The means of transport transports the associated one Bracket preferably along a closed Orbit between a station in which the to printing object is entered into the holder, and one Station in which the printed object from the holder is removed, the means of transport if necessary the linear movements in the individual printing stations transfers to the bracket that during the printing process are required to print object and squeegee in the relative position required for the printing process to hold to each other. Due to the fact that each bracket has its own, separately powered means of transport, which is advantageous in the form of a rotating toothed belt has, it is possible to use all brackets regarding their Control transports independently, so that one Bracket with the object she carries, for example several printing stations arranged one behind the other in the transport direction goes through, whereas another bracket independently of which can be brought to the station in which the printed article is removed from the holder and then immediately back to the receiving station if necessary can be moved to include the next object there, without losing the transport steps or the transport speed dependent on the at least one other bracket to be. The use of separate means of transport with separate Drives also have the advantage that the accuracy, with which the holder and thus the article carried by it perform the linear movements necessary for printing, is much larger than it could be if for several brackets a common means of transport and one common drive would be provided.

According to a further proposal of the invention, for each Bracket a special transmission means may be provided about which the rotational movements that the bracket and execute the object she is carrying during the printing process, be transferred to the bracket. This too will expediently uses a toothed belt with a Toothed belt wheel is engaged, which is connected to the bracket is. The individual transmission means are driven also via separate NC motors with the result that the pivoting or rotating movements of the brackets during printing can be carried out with great accuracy, to achieve the desired high print quality. This is especially important when objects with an irregular Cross-sectional shape can be printed.

For objects such as Bottles that are usually due their shape when printing or when performing other treatments in the device at both ends, usually are held on the bottom and neck sides, the bracket of two parts that are moved synchronously. In this Case, the arrangement is such that each bracket part is transported by a special toothed belt and further a special toothed belt is provided for each mounting part is the necessary during the printing process Transfer rotational movements to the object. It is the two timing belts for transport and the two timing belts for the transmission of the rotational movements Common NC motor assigned. Of course it is also possible use one-piece brackets when the shape of the Object requires or makes this possible.

In any case, the inventive design achieved that the respective masses to be moved are proportional are small. This also comes down to the accuracy of the printing process and thus the quality of the printed image.

By using individually driven individual means of transport and individual means of transmission there is also the possibility, if necessary, of an object To transmit movements that are independent of the movements, execute the other objects in the device. This means in cases where the printing units can be operated independently of one another in the printing stations and are controllable, the possibility in the individual printing stations To have printing processes run simultaneously, the different movements of the interacting parts require.

Furthermore, the stencil and squeegee can at least a printing unit can be moved up and down synchronously in order to irregularly shaped objects that occur during printing vertical shifts in the area to be printed to compensate for the object. In this case it is not required that the object be vertical when printed Undergoes shift. In any case, there are at least four program-controlled drives available, their movements with each other have to be coordinated.

Fig. 1

die Vorderansicht einer Siebdruckmaschine zum Bedrucken von Objekten,

Fig. 2

die dazugehörige Seitenansicht,

Fig. 3

einen Ausschnitt aus Fig. 2 in größerem Maßstab,

Fig. 4

im Schema die Anordnung von den Transport und den Antrieb der Objekte bewirkenden Elementen,

Fig. 5

in schematischer Darstellung ein Detail der Einrichtung für den Transport der Objekte,

Fig. 6

eine der Fig. 5 entsprechende Darstellung eines Details für den Antrieb der Objekte

Fig. 7a-i

den Ablauf des Druckvorganges,

Fig. 8

eine der Fig. 1 entsprechende Darstellung einer zweiten Ausführungsform

Fig. 9

eine der Fig. 2 entsprechende Darstellung dieser zweiten Ausführungsform,

Fig. 10

eine der Fig. 4 entsprechende Darstellung der zweiten Ausführungsform,

Fig. 11a-i

den Ablauf des Druckvorganges entsprechend der zweiten Ausführungsform

Preferred exemplary embodiments of the invention are currently shown in the drawing. Show it

Fig. 1

the front view of a screen printing machine for printing objects,

Fig. 2

the associated side view,

Fig. 3

3 shows a detail from FIG. 2 on a larger scale,

Fig. 4

in the diagram the arrangement of the elements causing the transport and the drive of the objects,

Fig. 5

a schematic representation of a detail of the device for the transport of the objects,

Fig. 6

a representation corresponding to FIG. 5 of a detail for the drive of the objects

7a-i

the sequence of the printing process,

Fig. 8

1 corresponding representation of a second embodiment

Fig. 9

1 corresponding representation of this second embodiment,

Fig. 10

4 corresponding representation of the second embodiment,

11a-i

the sequence of the printing process according to the second embodiment

The screen printing machine 10 shown in FIGS. 1-7 is provided with four printing stations I, II, III, IV, of which each a screen printing stencil 12a, 12b, 12c, 12d with each assigned doctor blade 14a, 14b, 14c, 14d. The machine 10 is provided with a base carriage 16 which on Machine frame 19 attached guides 15 horizontally in Direction of arrows 17, 18 is reciprocable. To the at both ends is the base slide with two vertical guides 23 provided. Fig. 1 shows that the base slide in Area between the two vertical guides 23 for Weight saving has a lower height than in the two end regions provided with the guides 23. At both Guides 23 a carriage 25 is vertically movable guided. Both carriages 25 carry the base carriage on their 15 facing away from an elongated support 27 on which all screen printing stencils 12a - 12d are attached.

The screen printing machine 10 is also in the area of the outer Printing stations I and IV are provided with vertical guides 21, which are attached directly to the machine frame 19. At every of these guides 21, a slide 20 is guided. At both An elongated support 29 is attached to the slide 20, on which all doctor blades 14a, 14b, 14c and 14d via cantilever arms 31 are attached.

On its side facing away from the squeegees, there is one on the carrier 29 attached substantially horizontal rail 34 to which Two pairs of rollers 36 abut on the top and bottom, which, as shown in particular in FIG. 2, in each case on the two carriages 25 are attached, up and along the guides 23 can be moved.

The back and forth movements of the base carriage 16 in the direction the arrows 17, 18 are effected by an NC motor 38 which drives a toothed belt wheel 40, which with a toothed belt 42nd is engaged, which also via a second toothed belt wheel 49 is led. The toothed belt 42 is connected to the base slide 16 connected so that the latter and with him the guides 23 and over the slide 25 and the carrier 27 with the base slide 16 connected screen printing stencils 14a-14d corresponding actuation of the NC motor 38 in the direction of Arrows 17, 18 can be moved back and forth. The vertical Movements of the printing units are brought about by an NC motor 22, which drives a shaft 24 on which two Toothed belt wheels 26 are attached, each with a Timing belts 28 are engaged. Above the vertical guides 21 a further shaft 30 is mounted on the machine frame, to which two toothed belt wheels 32 are attached by each of which is used to guide one of the toothed belts 28. Everyone the two toothed belts 28 are connected to one of the two slides 25 connected so that the carrier by actuating the NC motor 22 27 for the screen printing stencils 12a-12d and thus synchronously via the connection between rail 34 and roller pairs 36 also the carrier 29 with the doctor blades 14a-14d attached to it are moved, the carrier 29 on the carriage 20 on the laterally arranged guides 21 is guided. In which shown in Figures 1 and 2 take embodiment the squeegees on the floats towards the Arrows 17 and 18 not part, due to the connection a relative movement via the rail 34 and the roller pairs 36 between the arrangement carrying the squeegee and that Arrangement carrying screen printing stencils is made possible.

There is one below the screen printing stations I - IV Transport path along which the objects to be printed 39 step by step through each treatment and Printing stations I - IV are passed through. Because the screen printing machine is provided with four printing stations usually on the object in succession four printed images applied, which form a total printed image can add. But it is also possible, for example successively on the same surface area of the object, for example in stations I and II, two printed images to apply, which complement each other to form an overall printed image, and e.g. in printing stations III and IV two further printing images, that complement each other to form an overall print image on another Apply surface area of the object. The respective Type of application of the individual print images and the possible ones Combinations are familiar to any person skilled in the art, so that they need no special explanation here. In the direction of transport 18 of the objects can be set up behind each printing station be attached, by means of which the just applied Ink can be dried. In many cases these are UV lamps. These things are too familiar to any specialist, so that they are not explained in more detail will need. For reasons of clarity, these are UV lamps - or other drying devices - in the Drawing not shown.

Each object is transported through the press 10 carried by a bracket. There are two in total Brackets available that can be transported independently and be rotated.

Since the illustrated in the drawing as an embodiment Printing machine 10 for printing bottle-shaped objects serves that are held at both ends, each exists Bracket from two bracket parts 43a, 43b and 44a, 44b, of which the holding part 43a or 44a in the usual way receives the bottom portion of the object 39, whereas that thorn-like mounting part 43b and 44b in the Neck of the bottle-shaped object engages.

The transport path for the brackets 43a, 43b and 44a, 44b and the objects carried by these are encircled by a Rail pair 46a, 46b defines on which the brackets are led.

The bracket parts 43a, 43b; 44a, 44b are of accordingly the function of the bracket parts interacting in pairs Transport carts 48a, 48b and 50a, 50b carried. That's how they are Bracket parts 43a, 43b attached to the carriages 48a and 48b, respectively. The bracket parts 44a, 44b are from the carriages 50a and 50b carried. Each of the carriages is arranged in pairs Rollers 52a, 52b provided, each in one of the height of the distance corresponding to the respective rail 46a or 46b are arranged and on the respective rail 46a. 46b adjacent to the guidance of the respective carriage on the rail to serve.

The two rails 46a and 46b are circumferential in the vertical plane arranged so that an upper, essentially horizontal conveyor track section 53a and one vertically below located, essentially parallel lower Transport path section 53b is present and both transport path sections 53a, 53b at their mutually facing ends through an approximately semicircular transport track section 53c and 53d are connected to each other. In each of these two semicircular guideway sections 53c, 53d is an essentially horizontal coaxial one Shaft set 54, 55 arranged. The is related 1, the left wave set 54 the Car pair 48a, 48b assigned, whereas the right wave set 55 is assigned to the pair of wagons 50a, 50b.

The shaft set 54 is for transporting the holder 43a, 43b provided with a shaft 57 on which a coaxial shaft 56 is rotatably mounted, with which the toothed belt wheel 58 is fixed connected is. The toothed belt wheel 58 is over a toothed belt 60 driven by an NC motor 61. On the shaft 56 are also two toothed belt wheels 62a, 62b firmly attached, each drive a toothed belt 64a, 64b. Each of these timing belts 64a, 64b is in each case via a toothed belt wheel 66a, 66b, which is loosely arranged on the right shaft 55, such led that it runs parallel to the rails 46a, 46b.

The endless toothed belt running over the toothed belt wheels 62a, 66a 64a is connected to the carriage 48a, which the Holding part 43a carries. The over the toothed belt wheels 62b and 66b running endless timing belt 64b is with the carriage 48b for the bracket member 43b connected. About the actuation of the NC motor 61 can thus the transport of the bracket parts 43a, 43b object carried along by the rails 46a, 46b causes defined and controlled will.

Since the section of the bottle-shaped object to be printed unrolled on the screen printing stencil during the printing process must be to transmit the movements required for this a toothed belt wheel 70 with the shaft 57 on the object firmly connected, which via a toothed belt 72 from an NC motor 74 can be driven. Furthermore, there are two with the shaft 57 Toothed belt wheels 68a, 68b firmly connected. Each of these two Toothed belt wheels each drive a toothed belt 71a, 71b, which is also loosely arranged on the right shaft 55 Toothed belt wheel 75a and 75b is guided. The endless timing belt 71a is assigned to the carriage 48a and passed through it. For this purpose the carriage 48a has two guide rollers 83a, 83b, via which the toothed belt 71a with its smooth side runs. A toothed belt wheel attached to the car 85, which is driven by the toothed belt 71a, is fixed with connected to a shaft 84 which carries the holding part 43a. Accordingly, actuation of the NC motor 74 has a corresponding one Rotational movement of the holder part 43a and thus that of this carried object. Such Rotational movement can also be done by simply moving the carriage 48a along its determined by the rail 46a Transport path can be effected with the toothed belt 71a stationary. With a carriage moving along the guideway thus the rotational movement of that carried by the support member 43a Object result from this transport movement and a possibly simultaneous movement of the Toothed belt wheel 71a.

The arrangement of the parts described above and their Interaction applies in a corresponding manner to the toothed belt 71b and those carrying the associated mounting part 43b Carriage 48b. Due to the fact that the toothed belt wheels 62a and 62b or 68a and 68b each rigidly with one another and with the respective drive toothed belt wheel 58 or 70 firmly connected is an absolute synchronicity of the movements of the two Carriages 48a, 48b and thus the one carrying the object Bracket parts 43a, 43b guaranteed.

The two shown in the drawing in the lower position Carriages 50a, 50b of the holder 44a, 44b are in a corresponding manner Way on the right in Fig. 1 of the drawing Shaft set 55 driven, which is also assigned to two NC motors are, of which the NC motor 86 for transporting the two carriages 50a, 50b along the through the two rails 46a, 46b serves defined guideway and the NC motor 87 the drive of the holder parts 44a, 44b for the purpose of rotating the caused by these worn object. On the shaft 77 of the Shaft set 55, a coaxial shaft 78 is rotatably supported, with which several toothed belt wheels are firmly connected. The The toothed belt wheel 90 is driven by the NC motor 86 via a toothed belt 67 driven. There are also two toothed belt wheels on the shaft 78 88a, 88b firmly attached, each with a toothed belt 89a, 89b drive. Each of these toothed belts 89a, 89b is over one Toothed belt wheel 91a, 91b, which is loose on the left shaft 57 is mounted such that it is parallel to the rails 46a, 46b runs. Both timing belts 89a, 89b are each with one of the carriages 50a, 50b connected to this along the to transport the guideway defined by the rails 46a, 46b.

A toothed belt wheel 92 is fixedly connected to the shaft 77, which can be driven by the NC motor 87 via a toothed belt 73. Furthermore, two toothed belt wheels 94a, 94b are provided with the shaft 77 firmly connected. Each of these two toothed belt drives a toothed belt 95a, 95b, which also has a loose on the Left shaft 57 arranged toothed belt wheel 96a, 96b is. The toothed belt 95a is assigned to the carriage 50a and in already in connection with the toothed belt 71a and the carriage 48a described way passed through the carriage 50a. The toothed belt 95b is in a corresponding manner to the carriage 50b assigned. Both timing belts are used for printing or other treatments required rotational movement of the object carried by the holder 44a, 44b cause.

Both sets of shafts 54, 55 also carry an intermediate circuit suitable bearing stationary support 35. At the axial ends both carriers, the rotation of the shafts 58, 78 of the two Shaft sets 54, 55 do not participate, are holding means 63a, 63b attached, which the circumferential guide rails 46a, 46b carry.

It was already mentioned that when printing on an object, the area to be printed with respect to its cross-sectional shape of the circular shape or the shape of a circular arc the object differs depending on the cross-sectional shape a shift across the area to be printed Longitudinal axis experienced so that it is guaranteed that the area the surface of the object on which in the course of the printing process each transfer the printing ink through the squeegee is - in the following called "transfer area" - essentially tangent to the screen printing stencil and the squeegee always substantially perpendicular to the central axis of the Transfer area stands and thus the extension of the vertical Radius' of this transfer area should represent. There for example in an elliptically shaped body The circumferential direction of the surface to be printed on the individual Sections of the surface have different curvatures and therefore have different central axes, can be a permanent Moving the object perpendicular to its longitudinal axis be required to meet the aforementioned conditions - tangential Course of the transfer area to the screen printing stencil or Position the squeegee substantially perpendicularly above the Central axis of the transfer area - to be met.

FIGS. 7a-7i show the process of printing an im Cross section of elliptical object over the entire circumference of 360 ° shown, the screen printing stencil 12a in the X direction slide back and forth and the squeegee 14a in the X direction is arranged stationary. For the sake of simplicity, is only the contour of the object 39 is shown, which of the not bracket parts 43a, 43b shown, the via the toothed belt 64a, 64b by the program-controlled NC motor 61 have been transported into the position according to FIG. 7a, the positions of the interacting parts at the beginning of the Printing process shows. Which both in the direction of the X axis as screen printing stencil which can also be moved back and forth in the direction of the Y axis 12a takes its starting position for the printing process one that coincides with their left end position. The object 39 occupies a position in which its longer Cross-sectional axis runs horizontally and the doctor 14a itself vertically over the shorter cross-sectional axis of the object in Extension of the same and thus vertically above the longitudinal axis 81 of the cross section, which is in this position Parts are also the longitudinal axis of the transfer area. This means that in this position of the parts the longitudinal axis 81 of the cross section and the longitudinal axis of the transfer area collapse. The distance between the longitudinal axis 81 of the Screen printing stencil 12a is designated by "b" in FIG. 7a.

With the start of the printing process, the object 39 is over the Timing belt 71a, 71b by the program-controlled NC motor 74 pivoted in the direction of arrow 47 about its longitudinal axis 81, the screen printing stencil 12a by the program-controlled NC motor 38 shifted to the right in the direction of the X axis and simultaneously with the doctor blade 14a by the program-controlled NC motor 22 is raised in the direction of the Y axis so that the Fact to take into account that due to the elliptical Cross-sectional shape of the object 39 or the area to be printed same the transfer area on the lateral surface of the Object, each provided with ink by the squeegee becomes continuous in the course of the pivoting movement of the object moved up. Figure 7b shows an intermediate stage in the course of the printing process, in which the two axes of the cross section run obliquely. During the swivel movement, the object 39 that has experienced until then is the Central axis 81 around the distance l in the direction of the X axis against the squeegee 14a, which has been moved in the direction of the X axis is stationary. The necessary shift of the Bracket 43a, 43b in the direction of the X axis is also caused by the corresponding program-controlled NC motor 61, which drives the timing belts 64a, 64b5. The distance between central axis 81 and screen printing template in the intermediate position according to FIG. 7b is designated with "h".

Fig. 7c shows the relative positions of the interacting Share at a time when the longer axis of the Object cross-section runs vertically and the doctor blade 14a extending this axis perpendicular to the cross-sectional center located so that the longitudinal axis 81 of the object and Longitudinal axis of the transfer area collapse again. Consequently are in the course of the pivoting movement from the position shown in FIG. 7b into that of FIG. 7c the carriages 48a, 48b with those located thereon Brackets 43a, 43b again around the path l in the Starting position has been moved back according to FIG. 7a. In addition is that consisting of screen printing stencil 12a and squeegee 14a Printing unit has been further raised to the distance a to take into account the fact that the transfer area of the 7c position is higher than in the position shown in FIG Fig. 7b.

In the course of the further swiveling movement into the position according to 7d there is another lateral displacement of the object 39 to the above-described position of the squeegee 14a maintain the area of the object to be printed on, however this time the shift in opposite Direction, i.e. to the left. The in Fig. 7d distance l shown corresponds to distance l of FIG. 7b, since in both cases the object is essentially the same Angular position to the screen printing template, but in each case in the pointing in the opposite direction. According to the The height of the transfer area is the printing unit in FIG. 7d compared to the position shown in FIG. 7c slightly lowered.

In the course of the pivotal movement of the object from the position according to 7d into that according to FIG. 7e, in which the object 39 is one 180 ° pivoted position compared to that of Fig. 7a occupies, the carriages 48a, 48b are returned to the starting position 7a moved back so that when reaching the position 7e the squeegee again over the longitudinal axis of the Object and in extension of the shorter cross-sectional axis the same is located and the longitudinal axis of the object and the Longitudinal axis of the transfer area collapse again. At the same time, during this phase of the swivel movement Printing unit following the downward moving transfer area been lowered.

7f - 7i show the sequence of movements during printing the other side of the object 39. These movements correspond to those of Figs. 7a - 7e, so that in the end all parts return to the starting position according to FIG. 7a. This is however, in this embodiment, that the object 39 is printed over a range of 360 °. It is of course also possible and usual for the object to be printed only on a part of its circumference. In this Case could be the pivoting movement of the object, the vertical Movements of the screen printing stencil and the squeegee as well as the lateral one Displacement of the carriages 48a, 48b only to the extent that the print image requires to be performed. So could for example if the object is printed on one half the extent of the movements with reaching the position according to FIG. 7e.

Although the areas to be printed on in both exemplary embodiments objects are not circular Have cross-section, they are regularly trained than the area to be printed is elliptical Cross section with two axes of symmetry. The invention However, is by no means on printing objects with a limited such regular cross-sectional shape. It is possible to print even those objects, the ones to be printed Area has an irregular cross section, includes a flat surface, for example. Can also also such objects are printed, for example a have a substantially square cross-section, the Rounded edges and that between two adjacent edges areas are slightly curved outwards. It would be but also possible such objects with rounded edges then to print if the between two adjacent edges surface is completely flat, so it is not curved.

When printing on surfaces that are circular in cross-section are or form the section of a circle, are those described above Movements of the object in the direction of the X axis and the Y axis are not required.

1-4 are the station VI, in which the bottle to be printed is placed in the holder 43a, 43b or 44a, 44b is given, and station VII, in which the printed bottle from the respective holder is removed, the lower portion 53b of the transport path assigned. The insertion of the bottle to be printed on the bracket located in the receiving station VI takes place via a gripper 79a, which can be moved three-dimensionally and the bottle transported by a conveyor 97a records and by overlapping swivel movements the bottle from vertical to horizontal position and at the same time brings it into the receiving station VI, in which one of the two parts of the respective located there Bracket is included. The two are known mount the object-carrying bracket parts so that the distance between them can be changed so the two mounting parts hold the objects to be printed and can hold to release the printed object later to be able to. With those shown in the drawing Embodiments is only that with the neck side End of the bottle-shaped object 39 cooperating Bracket part 43a, 43b parallel to the longitudinal axis of the of the Bracket parts worn object slidable in each associated carriage 48b, 50b arranged. That’s it Bracket part 43b, 44b provided with a cam roller 101, those in the receiving station VI and in the removal station VII cooperates with a curve section 103 which is parallel to Direction of transport of the object in the area of the aforementioned Stations runs. The curve section 103 is by a pneumatic cylinder-piston arrangements 105 transversely to the direction of transport slidable. During the movement of the bracket parts in the direction of arrow 17 (Fig. 1) in the removal station VII runs on the mounting part 43b or 44b located cam roller 101 in the curve of the curve section 103 a. After reaching the removal station IV, the gripper 79b along the rail 99b in FIG Representation of Fig. 1, left end position and move into Removal station swiveled around the one still there the object to be carried on the mounting parts. Thereupon is activated by a corresponding actuation of the cylinder-piston arrangement 105 the bracket 44b from the bracket 44a moved away by a distance that is sufficient for now object carried by the gripper 79b on its neck side Release end. The gripper then performs a short movement towards the neck-side mounting part 44b, to disengage the object from the bottom receptacle 44a bring. Then the gripper can move the object along the Rail 99b shifted towards conveyor 79b and so be pivoted that he the printed object in vertical Position on the conveyor 79b, as shown in Fig. 1st is shown. The bracket 44a, 44b can then in the receiving station VI are moved forward, the holding part 44b maintains its position in which it maintains its greater distance from the holding part 44a, so that after reaching the pick-up station VI the gripper 79a an object that he previously has decreased from conveyor 97a, in a horizontal position first brings between the two mounting parts 44a, 44b and then parallel by a corresponding movement to the longitudinal axis of the object, its bottom area into the holder 44a. Then through the in the receiving station VI located cylinder-piston device 105 of the curve section 103 located there taking the curve roller located in the curve of this curve section 101 shifted in the direction of the holding part 44a with the Result that the holding part 44b in the neck of the object 39 intervenes, so that the latter of the two Bracket parts is worn. The gripper 79a can now Release the bracket part and put it in the position for receiving of the next object.

In the course of the gradual advance transport of the Bracket 44a, 44b object in the lower section 53b of the transport path in the direction of arrow 18 Cam roller 101 out of engagement with cam portion 103 After reaching the upper section 53a of the transport track in In the direction of arrow 18, the object can be reached before the first Printing station I any additional treatments be subjected. The object can be dusted, flamed and be aligned in the circumferential direction. After pretreatment the object is then brought into the first printing station I, in of the parts immediately before printing begins assume positions described with Fig. 7a. After completion the printing process in the printing station I then takes place Transport to printing station II, in which the next one Print image is applied. After applying the last print image in station IV the object arrives after passing through of section 53c of the transport path again in the lower Section 53b and there into the removal station VII, in which through the object in the manner already described the gripper 79b is removed from the holder.

Due to the fact that both brackets 43a, 43b and 44a, 44b moved independently of one another along the transport path there is the possibility, for example after application of the last print image, the object immediately into the removal station VII to be transported and after removal of the printed Object from the holder immediately into the receiving station Move VI to pick up the next object there. There is still the possibility in the located between receiving station VI and printing station I. Treatment stations to perform all desired treatments, without this by transporting the other bracket (s) would be hindered or delayed. This is opposite known machines a significant increase in productivity achieved.

The embodiment shown in Figures 8 and 9 largely agrees with the exemplary embodiment according to FIG. 1 - 4 match, so that the same or corresponding parts are provided with the same reference numerals, but in the 8-11 are 100 larger. In terms of printing technology, there is essential difference between the two embodiments in that the screen printing stencils 112a, 112b, 112c, 112d, 112e of the five printing units arranged stationary insofar as no parallel movements during the printing process its main plane, i.e. in the direction of the X axis. Therefore the doctor blades 114a, 114b, 114c, 114d, 114e are essentially parallel to the main level of the respective associated Screen printing template and perpendicular to the longitudinal axis of the printing object arranged to slide back and forth to the relative movement required for the printing process between To effect screen printing stencil and associated squeegee.

In this embodiment, too, each is made of a screen printing stencil and squeegee existing printing units vertically up and down arranged to be movable in the case of objects whose printing surface in cross section from the course of a circle or circular section that deviates in the course of the from the object executed pivoting movement changing altitude of each transfer area adjacent to the screen printing template to be able to follow. An NC motor 122 is provided for this purpose, which drives a shaft 124 on which two toothed belt wheels 126 are attached, each with a vertical Timing belts 128 are engaged. Above the two Toothed belt wheels 126 are at a distance from these two Toothed belt wheels 132 are arranged, each for guidance one of the timing belts 128 is used. Each of the two timing belts 128 is via a cross member 109 with a carriage 125 connected, which is guided on vertical guides 121, which on Machine frame 119 are attached. On this sled 125 all screen printing stencils 112a-112e are attached. Further is the carriage 125 with two at a distance from each other extending substantially horizontal guides 115 on which a carriage 116 is substantially horizontal which can be pushed back and forth, all the doctor blades 114a - carries 114e over cantilever arms 131. The floats of the Doctor slides 116 are caused by an NC motor 138, the one of two interacting telescopically Shaft sections 141, 145 existing shaft a toothed belt wheel 140 drives. A toothed belt 142 is around this toothed belt wheel 140 and a second one at a horizontal distance Belt pulley 149 guided. The two toothed belt wheels 140 and 149 are arranged on a carrier 151, the back is attached to the carriage 125. So the two take Toothed belt wheels 140, 149 and back and forth in the horizontal plane movable toothed belt 142 on the up and down movements part of the slide 125, with the telescopic interaction of the two shaft sections 141, 145 the changes the distance between the NC motor 138 and the toothed belt wheel 140 are made possible. The timing belt 142 and that on the guides 115 guided slides 116 are by at least one Traverse 159 connected together so that the horizontal Level slides of the carriage 116 with the doctor blades located thereon caused by the toothed belt 142 will.

Also with regard to the means for transporting and pivoting the holders for objects 139 and the ones required for them The embodiment according to FIGS. 8 and 9 is correct for the drives with that in accordance with FIGS. 1 and 2 in principle. To is particularly referred to Fig. 10, which the arrangement of the Shaft sets and the individual toothed belt wheels they carry with the timing belt. Also in Fig. 10 are all parts, the parts of the embodiment according to the 1 - 4 correspond, with the same, but around each 100 higher reference numerals. The arrangement according to FIG. 10 allows a somewhat more compact construction than the arrangement 4.

11a-11i is analogous to the representation in the figures 7a - 7i the sequence of movements during the printing process interacting parts shown when the screen printing stencil stationary parallel to the X-axis and the doctor blade parallel is arranged to be displaceable to the X axis. It is necessary that the object 139 in during the printing process Direction of the X-axis is moved to the one to be printed Unroll surface areas of the same on the screen printing template. This movement is about the object supporting Bracket parts 143a, 143b by the NC motor 161, which the drives two timing belts 164a, 164b, with which the two Carriages 148a, 148b are connected for the mounting parts transfer the object. However, since according to the device Figures 8 and 9, an object is printed, the to printing surface has a cross section that of the Circular shape deviates, there is also a need here additionally to move the object in the direction of the Y axis, to ensure that the transfer area of the object in the runs essentially tangential to the screen printing stencil and the squeegee is substantially perpendicular to the central axis of the Transfer area stands. If the doctor blade in the course of the printing process at a constant speed relative to the direction the X-axis fixed screen printing template, for example from the position according to FIG. 11a into the position according to Figure 11b is moved, it is necessary to move simultaneously transport movement of the object in the same direction to overlay a second movement. This is the NC motor 161 programmed to result in a movement in which the squeegee according to when the position is reached Figure 11b not over the central axis 181 of the cross section of the object to be printed, but opposite this center offset to the right, based on the representation of the figure 11b, is to meet the above condition, that the squeegee is over the center or over the central axis located to the radius of curvature of the transfer area belongs to the object surface. In the specific case this means that the movement of the object between the two Positions of Figures 11a and 11b relative to that in the same Lags somewhat in the direction of the movement of the squeegee, namely for the way l. The doctor blade is located in FIG. 11c again exactly over the central axis of the object cross section, the at this time also the central axis of the transfer area is, so that the movements of object and squeegee in Direction of the X axis - again depending on the cross-sectional shape of the area to be printed - with different resulting speeds are such that in this printing phase the squeegee slows in somewhat slower The direction of the X axis is moved as the object. In the next Phase of the printing process, i.e. when the interacting parts from the position shown in Figure 11c in 11d, doctor blade and object are again in Depends on the cross-sectional shape of the in this phase printing area with different Speeds moved such that the object around the Distance l leads, which is the distance in the X axis between the axis 181 about which the object is rotated, and the The position of the squeegee corresponds. In the next phase of Printing process, at the end of which the parts correspond to the positions Figure 11e in turn, the object will again result moved slower in the X-axis direction than the squeegee, so that at the end the squeegee over the axis of rotation 181 of the object stands.

Figures 11f - 11i show the sequence of movements during Printing on the other side of the object 39. Here there is with regard to the course of the movements agreement with the process described in connection with FIGS. 11a-11e.

For the bracket parts 144a and 144b and the one they support The same applies accordingly.

The vertical common movements of screen printing stencil and doctor blade agree with those of the embodiment according to the Figures 7a - 7i match, since the cross-sectional shapes of the Objects match.

In the embodiment according to FIGS. 8 and 9, the two stations, in which the objects to be printed in the Brackets are inserted or the printed objects out these brackets are taken out, the upper section 53a assigned to the transport track, whereas in the case of the Embodiment according to FIGS. 1 and 2, as already explained, these stations are assigned to the lower section 53b are. Which of the two options is preferred depends on the respective circumstances, e.g. of whether in the area of the transport track 53c or 153c any further Pretreatments should be done before the first Printing process takes place. Otherwise, the device 8 and 9 of the first printing station I one more in the area of the upper transport track section 153a Upstream station, in which the objects in the circumferential direction be aligned.

When printing on objects after the printing process require special treatment to dry the ink, can for example stations II and IV of Device according to Figures 8 and 9 by one Drying device, for example a UV lamp replaced if necessary, when transporting the objects from one printing station to the following printing station move essentially in sync with these objects can, if this increases the productivity of the machine.

It is pro depending on the desired production Unit of time also possible, the device with more than two Brackets.

In many cases, the application of the individual print images so that a printing process only in one of the total existing printing stations is carried out, whereas the other stations run along empty. Dependent on from the cross-sectional shape of the area to be printed on Object can exist in the presence of, for example, two Brackets in two stations simultaneously printing processes be performed when the vertical movements of the Printing units in both stations match.

There is also the possibility of at least one of the printing stations in another way, e.g. such that the Screen printing template is fixed and the squeegee transversely to the transport direction 18 for applying the printing ink to the object is moved relative to the screen printing stencil. Such Arrangement is e.g. then useful if the object is in has essential flat surface section to be printed is. In this case, screen printing stencil and need Object does not move relative to each other during printing will.

It is of course also possible to use the mounting parts to be attached vertically up and down to the respective car, depending on the cross-sectional shape itself changing vertical distances between the transfer area and the axis of rotation to compensate, so that the printing units then could be arranged stationary in the vertical direction. The vertical movement of the printing units, as in both the drawing shown embodiments provided is, however, becomes clearer and clearer in many cases less complicated movement relationships in the individual Lead printing stations. In any case, regardless of which parts perform the vertical movements remains obtain significant advantage of the device according to the invention, which consists in the fact that when changing from an object type to another type of property, which also involves a change of Bracket parts and possibly other movements of the interacting Parts required, only the actual ones Bracket parts need to be replaced. All other Elements from the drives to the toothed belt wheels and Wagons can be kept. There is only the Need the program by which the motors are controlled be adapted to the new object type.

Claims (14)

1. Apparatus for printing on an article, wherein there are provided at least one rotatably arranged holder (43a, 43b; 44a, 44b) for the article (39) and at least one printing mechanism having a screen printing stencil (12a-12d) and a squeegee (14a-14d) displaceable relative to the screen printing stencil, and a transport means (64a, 64b; 89a, 89b) for the holder, the transport means transporting the article (39) between a station in which the article is introduced into the holder and a station in which the article is removed from the holder, characterised in that the apparatus is provided with at least two holders (43a, 43b; 44a, 44b) and for each holder a separate drive (61; 86) is provided for the transport means (64a, 64b; 89a, 89b) and a separate drive (74; 87) is provided for the transmission means (71a, 71b; 95a, 95b) for transmitting the rotary movement to the holder and the drive means (61; 86; 74; 87) for the transport means (64a, 64b; 89a, 89b) and the transmission means (71a, 71b; 95a, 95b) as well as the drive means (38) which produce the relative movement between the screen printing stencil and the squeegee are in the form of NC-motors.
2. Apparatus as set forth in claim 1 characterised in that, when printing on an article (39) whose surface to be printed deviates from the shape of a circle or a circular arc, the holder (43a, 43b; 44a, 44b) which carries the article is laterally displaced by the transport means (64a, 64b; 89a, 89b) associated with the holder in order to hold the article (39), in dependence on the cross-sectional shape of its region to be printed upon, in the position required for the printing operation, relative to the squeegee (14a-14d), in which position the squeegee extends substantially perpendicularly over the central axis of the transfer region of the article on to which the respective printing ink is applied.
3. Apparatus as set forth in claim 1 characterised in that the at least one screen printing stencil (12a-12d) is arranged to be laterally stationary during the printing operation and the squeegee (14a-14d) moves laterally relative to the screen printing stencil (12a-12d) for applying the print image to the article (39) and the movement required for rolling the article against the screen printing stencil for the purposes of applying the print image is transmitted to the article by the transport means (64a, 64b; 89a, 89b).
4. Apparatus as set forth in claim 1 characterised in that the at least one squeegee (14a-14d) is arranged to be laterally stationary during the printing operation and the screen printing stencil (12a-12d) is laterally displaced relative to the squeegee for applying the print image to the article (39).
5. Apparatus as set forth in claim 1 characterised in that the screen printing stencil (12a-12d) and the squeegee (14a-14d) of the at least one printing mechanism are arranged to be movable upwardly and downwardly jointly and the upward and downward movements are produced by NC-drive means (22) in order to compensate for the vertical displacement of the transfer region of the article (39), which occurs when printing on articles which are non-circular in cross-section.
6. Apparatus as set forth in claim 1 characterised in that the transport means (64a, 64b; 89a, 89b) is in the form of at least one toothed belt connected to the associated holder (43a, 43b; 44a, 44b).
7. Apparatus as set forth in claim 1 characterised in that the transmission means (71a, 71b; 95a, 95b) is in the form of at least one toothed belt which co-operates with a tooth configuration (85) provided at the associated holder (43a, 43b; 44a, 44b).
8. Apparatus as set forth in claim 1 characterised in that it is provided with two sets of shafts (54, 55) and the shafts (56, 57; 77, 78) of each set are rotatable about a common axis and the axes of the two sets of shafts are arranged at a spacing from each other and the shafts carry wheels (62a, 62b; 68a, 68b; 91a, 91b; 96a, 96b; 66a, 66b; 75a, 75b; 88a, 88b; 94a, 94b) for driving and for guiding the transport means (64a, 64b; 89a, 89b) and the transmission means (71a, 71b; 95a, 95b) respectively.
9. Apparatus as set forth in claim 6 and claim 7 characterised in that, where a holder for the same article (39) comprises two holder portions (43a, 43b; 44a, 44b), a transport means (64a, 64b; 89a, 89b) and a transmission means (71a, 71b; 95a, 95b) are provided for each holder portion and the two transport means and the two transmission means are each driven by the same respective NC-motor (61; 74; 86; 87).
10. Apparatus as set forth in claim 1 characterised in that all screen printing stencils (12a-12d) are carried by a common carrier element (27).
11. Apparatus as set forth in claim 1 characterised in that all squeegees (14a-14d) are carried by a common carrier element (25).
12. Apparatus as set forth in claim 1 characterised in that the carrier element (27) for the at least one screen printing stencil (12a-12d) and the carrier element for the at least one squeegee (14a-14d) are connected together in such a way that both carriers can perform reciprocating movements relative to each other in the printing direction and in the opposite direction thereto and are positively lockingly connected together in the vertical direction.
13. A screen printing process for decorating individual articles (39), each of which is held during the printing operation by a holder (43a, 43b; 44a, 44b) which is transported intermittently through the treatment stations, wherein each holder is provided with means (71a, 71b; 95a, 95b) which transmit a rotational movement to the holder and the article (39) held thereby, characterised in that each holder is transported independently of the at least one other holder and that each holder is rotated at least during the printing operation, independently of the at least one other holder, and that during the printing operation, when printing on surfaces which deviate from the shape of a circular arc, the article is moved by the transport means (64a, 64b; 89a, 89b) in the transport direction (117; 118) and/or in the opposite direction thereto, in dependence on its cross-sectional shape, in order to hold the article, in dependence on the cross-sectional shape of its region to be printed upon, in the position relative to the squeegee (14a-14d), being the position which is required for the printing operation and in which the squeegee extends substantially perpendicularly over the central axis of the transfer region of the article, on to which the respective printing ink is transferred.
14. A process as set forth in claim 13 characterised in that the printing mechanism comprising a screen printing stencil (12a-12d) and squeegee (14a-14d) is vertically raised and/or lowered in order to compensate for the vertical displacement of the transfer region of the article, which occurs when printing on articles which differ in cross-section from the shape of a circular arc.

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