DE19908849A1 - Ink pot for tampon printer has holder -ring, annular doctor blade edge, magnetic body in magnet holder ring, connection of grooves and protuberances - Google Patents

Abstract

A holder-ring (1) forms a casing wall for the ink-pot the lower end of which has an annular doctor blade edge (42). A magnet holder-ring (2) has at least one magnetic body (52). A plug-in-turning connection joins the holder-ring and the magnet-holder-ring by plugging them axially together and locking them by a relative turn of less than 360 degrees. The plug-in-turning connection has at least one pair of two grooves (30) in the ring's outer peripheral surface, and has protuberances (36) on the magnet-holder-ring fitting into the grooves.

Description

The invention relates to a paint pot for Pad printing machines according to the preamble of claim 1.

A paint pot of this type and a pad printing machine, in which such a paint pot can be used are from the Patent specification US 4 905 594 (= EP 0 315 769 B1 known).

Pad printing machines and ink pots for it are also out the following documents are known: US 5 662 041 and 4 557 195 (= EP 0 140 165 B1), layout specification DE 19 23 374, Patent DE 22 05 430 C3 (= CH 522 507); GB 1 135 819. It is also known from DE 33 02 317 A1 and EP 0 061 093 known, squeegee edges for squeegees from printing machines Metal or non-metal, steel or hard metal or manufacture ceramic materials. The squeegee edge can by the lower end of the squeegee pot or by an am Squeegee pot attached squeegee element can be formed. The  Mantle wall of the paint pot including that on it Jacket wall self-made doctor edge can be made of steel or completely as described in U.S. Patent 5,662,041 are made of plastic.

In the ink cup according to the invention, the doctor edge and the body constituting it from any of the known ones mentioned materials exist.

The object of the invention is to solve a problem Possibility to create, through which the handling of the Paint pot facilitates and the axial power transmission between ink cup and cliché is optimized.

This object is achieved according to the invention by the characterizing features of claim 1 solved.

The invention contains the following essential ideas:

• 1. The print quality can be significantly improved, if the squeegee edge does not pass through the jacket wall of the Color pot is formed, but by a separate Doctor ring.
• 2. The doctor ring is designed as a wearing part, which is often very expensive relative to that The cliché may wear out more than the cliché. Therefore is a simple change option according to the invention to replace the doctor ring without tools by the Intended for users.
• 3. The connection of the doctor ring and the the wall of the Pot-forming receiving ring is made via a commercially available O-ring (wearing part), which is characterized by its  Deformation of the holding force of the doctor ring against the Receiving ring generated. The doctor ring is according to the invention preferably designed in its inner contour so that it lies in the axial direction on the O-ring and thus has a defined damping behavior. Thereby the doctor ring can have radial and axial movements relative run to the receiving ring, taking cliché unevenness be balanced and the O-ring by the doctor blade process generated alternating loads dampens.
• 4. Permanent magnet bodies are only diagonal to each other opposite points, but not in the area of one Diagonals that are offset by 90 ° to the direction of squeegee movement is arranged. As a result, they act with a long Lever arm tilting moments of the paint pot counter that Squeegee reversal movements occur during the squeegee process. This allows the total pressure of the squeegee edge on the Cliché be reduced. This has a reduced one Wear of these parts.
• 5. Guide bolts fastened in the magnetic retaining ring engage Locking grooves, which are formed in the receiving ring and thereby define the position of the Magnetic retaining rings relative to the receiving ring, which the Sheath wall of the paint pot forms. Preferably there are several optionally usable grooves provided. The user can thus the one that occurs more strongly in the direction of squeegee movement Counteract wear by changing the ink cup system by 90 ° or rotated 180 °. The positions are preferably marked legibly on the circumference of the receiving ring.
• 6. Defined dimensions between the magnetic retaining ring and the cliché of the pad printing machine by different grooves in the receiving ring allow one  targeted use, d. H. a targeted use in different cliché materials.
• 7. In addition to the locking grooves, or instead this, can in the outer circumference of the receiving ring axially parallel through grooves are formed, in which the Magnetic retaining ring as an alternative to the locking grooves can be used and in which it is guided axially in order to the squeegee ring of the receiving ring pull the trigger. The disassembly option of the doctor ring by means of the magnetic retaining ring allows a quick Replacement of the doctor ring. This will take the user into the Position offset, doctor rings with different Cutting geometries, materials and / or Surface coatings optimized for the respective Adapt cliché type.
• 8. Preferably there is a removable on the receiving ring Sealing cap arranged so that paint in the paint pot can be refilled without the ink cup from the Pad printing machine needs to be removed.
• 9. According to a preferred embodiment is in the Sealing cover is a venting option for venting of the paint pot integrated. The receiving ring is on for this a predetermined position on its circumference with a Provide ventilation duct. By twisting overlying cap will be one in it located opening for covering with the ventilation duct brought. This enables the squeegee movement escaping gases escape to the outside and prevented thus an overpressure in the interior of the pot, which is necessary for lifting the Ink cup system from which cliché could lead. At prolonged downtimes or when filled with paint  The ink pot as preparation for a printing process becomes the Closure blanket arranged on the receiving ring or twisted that the opening in the cap hermetically seals with the contour of the receiving ring and thus prevents a chemical reaction of the color or at least delayed.
• 10. According to a further preferred embodiment of the Invention, a bottom closure lid is provided, which it allows you to fill the paint pot with paint and in store and / or sell filled, and which is for use in a pad printing machine then easily separable from the paint pot.

The invention is described below with reference to the Drawings based on a preferred embodiment as Example described. Show in the drawings

Fig. 1 is an exploded view of the parts of a paint pot system according to the invention arranged one above another in such a way as they can be connected together by axially assembling,

Fig. 2 is a vertical, diagonal axial section through a paint pot according to the invention, formed by axially assembling the parts of Fig. 1 without a shown there magnet holding ring, already filled with ink and prepared for insertion into a pad printing machine,

Fig. 3 is a vertical, diagonal axial section through a paint pot according to the invention, formed by the axially assembled parts of Fig. 1 without a shown there bottom closure lid, but with a magnet holding ring, ready for insertion into a pad printing machine,

Fig. 4 is a side view of a casing wall of the ink cup forming the receiving ring,

Fig. 5 is another side view of the receiving ring,

Shows a bottom view, arranged on both sides. 6 of a magnet holding ring of the ink cup with uniformly distributed on four circumferential points magnet assemblies and intermediate magnet-free peripheral areas symmetrical to a squeegee movement line, perpendicular through paint pot centerline,

Fig. 7 is a bottom view of a further embodiment of the magnetic retaining ring having two magnetic assemblies at 180 ° diagonally opposite points on a diagonal, which extends in the direction of squeegee movement,

Fig. 8 shows a schematic axial section of a further embodiment in the locking position,

Fig. 9 shows the embodiment of Fig. 8 in the doctor-pulling position.

As the drawings show, the invention not only offers a new paint pot, but an entire paint pot system.

Referring to FIG. 1, a magnetic retaining ring 2 and from below a doctor blade ring 3 is here pushed onto a receiving ring 1 from above. On the upper edge of the receiving ring 1 , a top cover 6 can be attached. This top closure cap 6 can be placed on the receiving ring 1 before or after the magnet retaining ring 2 , since the inside diameter of the magnet retaining ring is larger than the outside diameter of the top closure lid 6 and the outside diameter of the upper section of the receiving ring 1 . A bottom cover 7 can be plugged onto the doctor ring 3 from below.

In Fig. 1, the magnetic holding ring 2 is not shown diagonally cut, in contrast to Fig. 3, but Fig. 1 shows left and right different axial sectional planes that intersect in the ring center axis.

As a result, the paint pot, with or without the magnetic holding ring 2 , can be filled with paint as long as only one of the two sealing covers 6 or 7 is attached. After filling the paint pot, the second cover 6 or 7 is also attached to the paint pot. As a result, the ink fountain filled with ink can be stored or shipped for printing either from the ink manufacturer or from the supplier of the ink fountain or from the user who inserts the ink fountain into a pad printing machine. Another advantage is that the bottom cover 7 protects the doctor edge of the doctor ring 3 .

According to a modified embodiment, the bottom closure cover 7 can be pushed onto the lower end of the receiving ring 1 instead of onto the doctor ring 3 . In this case, the doctor ring 3 is only put on the user instead of the closure cover 7 on the lower end of the receiving ring 1 .

In the preferred embodiment according to the drawings, the receiving ring 1 has a lower section 10 , which has a larger inside and outside diameter than its upper section 12 . In the lower end region of the lower section 10 , a radially projecting O-ring made of spring-elastically compressible material 16 is inserted into an annular outer circumferential groove 14 . The doctor ring 3 can be plugged onto this O-ring 16 and is held on the receiving ring 1 by the resilient clamping force of the O-ring 16 . An inner circumferential groove for receiving the part of the O-ring 16 protruding from the outer circumferential groove 14 can be formed in the doctor ring 3 . The doctor ring 3 can rest on the outer circumference of the lower section 10 without play, so that it can make no transverse movements or pivoting movements and only limited or no axial movements relative to the receiving ring 1 . According to a preferred embodiment of the invention, however, there is so much leeway between the receiving ring 1 and the doctor ring 3 that they can be moved on all sides relative to one another and are supported elastically against one another radially and axially only by the O-ring 16 .

In the doctor ring 3 , an inner circumferential groove 18 is formed, which is adapted to the shape of the O-ring 16 . The O-ring 16 projects radially into this inner circumferential groove 18 . To reduce the friction between these parts, the doctor ring 3 has a larger inner diameter from the inner circumferential groove 18 upwards than downwards. As a result, the wall of the inner circumferential groove 18 encompasses the O-ring 16 at the top less than at the bottom.

Referring to FIGS. 2 and 3 is given by a simple venting possibility that in the top- sealing cover 6 in the area of its opposite end face 22 of the receiving ring 1, at least one vent opening 24 is formed by rotating the top-sealing lid 6 relative to the mounting ring 1 is optionally can be closed by the end face 22 as shown in FIG. 2 or with at least one ventilation channel 26 can be covered according to FIG. 3, which is formed in the end face 22 and leads into the interior of the receiving ring 1 .

Referring to FIGS. 1 to 4 of the receiving ring 1 is formed at least one pair of two positioning slots 30 at diametrically opposite locations in the outer circumference of the lower portion 10, which open at the upper end of the vertical groove portion 32 and an adjoining the lower end of the circumferential Groove section 34 have a bayonet lock to form a plug-turn connection.

The magnet holding ring 2 is provided with at least one pair of two diametrically opposite, radially inwardly projecting projections, preferably in the form of inserted guide bolts 36 . The guide pins 36 engage when attaching the magnet retaining ring 2 to the mounting ring 1 is first in the vertical guide portions 32 and then through rotation of the magnet holding ring 2 relative to the mounting ring 1 in the Umfangsnutabschnitte 34, whereby the magnet retainer ring 2 is held in a defined axial position and rotational angular position of the receiving ring 1 .

Referring to FIGS. 1 and 3, the magnet holding ring 2 (and / or the receiving ring 1) on its outer circumference with at least one recess 38, preferably provided with two spaced-peripheral portion of recesses 38 into which a gripper can engage a pad printing machine to the To hold the ink fountain in a rotation angle position determined by the position of the recess 38 on a cliché and to move it transversely to the center of the ink fountain 40 on a cliché in the doctor blade direction 39 .

With such a shift, a tilting moment arises in the ink cup due to the friction of the doctor edge 42 of the doctor ring 3 on the cliché 44, on the one hand, and the displacement force of the gripper of the pad printing machine, which acts on the ink cup or on the magnetic holding ring 2 on its recesses 38 with as little height as possible. As a result of these, although usually only small, moments, the squeegee edge 42 in the squeegee movement direction 39 is more worn at the front and rear than at the left and right of the ink fountain center line 40 . The invention makes it possible, instead of rotating the squeegee edge 42 relative to the receiving ring 1 , in a simpler manner to rotate the entire ink fountain about its central axis until the gripper can engage in other recesses 38 . The positions of the recesses 38 define predetermined rotational angle positions of the ink cup on the plate 44 .

In addition, or instead, a further aspect of the invention, in the outer circumference of the receiving ring 1, according to a plurality of pairs be formed by positioning grooves 30 angularly offset so that the retainer ring 1 is rotated relative to the magnetic retaining ring 2 in different rotational angular positions and the defined rotational angular positions in each of the guide pins 36 with another pair the positioning grooves 30 can be engaged. Such defined rotational angle positions are preferably arranged rotated relative to one another by 90 ° about the central axis 40 of the ink fountain.

In another, shown in Fig., 5 idea of the invention formed in the outer periphery of the lower portion 10 at the other diametrically opposite locations as the positioning grooves or instead of positioning grooves 30, axially parallel guide grooves 46th The guide grooves 46 are open at both ends on the groove end face and their lower end is opposite the upper end of the doctor ring 3 . In these guide grooves 46, the magnetic holding ring 2 with its guide pin 36, instead of being inserted into the positioning grooves 30 in order to pull the trigger with the retaining ring 2 and its pressing on the blade ring 3 guide pin 36 to the blade ring 3 of the receiving ring 1 to remove ie axially. The doctor ring 3 is particularly difficult to remove from the receiving ring 1 when it is glued to it by color. In addition, the use of the magnetic holding ring 2 is safer for an operator than holding the doctor ring 3 in the vicinity of the often sharp doctor edge 42 .

For the embodiments described above, it is not necessary that the retaining ring 2 be a "magnetic retaining ring". When using a magnetic holding ring 2 , the ink cup is magnetically attracted by the magnetic force of the magnetic holding ring 2 with the squeegee edge 42 against the surface of the cliché 44 , provided that the cliché is magnetizable or near the cliché magnetizable material, e.g. B. iron is arranged. When using a retaining ring 2 , which is not magnetic or contains no magnets, the squeegee edge 42 must be pressed against the surface of the plate 44 either by permanent magnets, which are attached to the receiving ring, or by the named gripper of the tampon printing machine, so that none of the ink cup Ink can escape between the squeegee edge 42 and the plate 44 and the squeegee edge 42 can cleanly squeegee the ink on the plate 44 .

However, the use of a magnetic or magnet-provided retaining ring 2 has several advantages, e.g. B. a simpler and cheaper construction of the paint pot and the possibility to use the retaining ring 2 for several interchangeable paint pots.

In the preferred embodiment shown in FIG. 6, magnetic forces of the same strength are not provided around the entire circumference of the magnetic holding ring 2 , but the magnetic forces are distributed over four locations around the magnetic holding ring 2 , these four locations having an average angular distance of 90 ° from one another have and the diagonals, on each of which two of these four locations lie, are arranged at an angle of 45 ° to the doctor movement direction 39 . At each of these four locations there is at least one permanent magnet 52 on an iron base 53 , three permanent magnets 52 being shown at each location in FIG. 6. Magnet-free peripheral regions of the magnet holding ring 2 are located between these four locations. This has the advantages that the above-mentioned tilting moments of the ink fountain during its squeegee movement in the squeegee movement direction 39 can be absorbed by the magnetic forces via a long lever arm. This advantage is also maintained when the magnet retainer ring 2 together with the mounting ring 1 and the blade ring is rotated by 90 ° or 180 ° 3, in order to compensate a one-sided abrasion of the blade edge 42 which is produced by said tilting moments. Figs. 1 and 3 show side views of the permanent magnets 53 and the iron bases 53.

According to another embodiment of the invention, which is shown in FIG. 7, permanent magnets 52 are arranged instead of at four magnetic locations only at two magnetic locations offset by 180 degrees of rotation relative to one another on a diagonal which extends in the doctor movement direction 39 . Here, however, the ink cup with its squeegee edge 42 must be rotated by 180 ° in order to compensate for uneven doctor blade edge wear caused by the aforementioned tilting moments. The advantage is longer lever arms, on which the magnetic forces act against the tilting moments. The permanent magnets 52 can be arranged on the same paint pot at the same time both according to FIG. 6 and according to FIG. 7.

The magnet arrangements of FIGS. 6 and 7 can also be used when the permanent magnets 52 are not fastened to a retaining ring 2 , but rather to the receiving ring 1 or to another hollow body which forms an outer wall of the paint pot.

In the embodiment shown in FIGS. 8 and 9, an upper sealing cap 6 and a lower sealing cap 7 can again be used. The difference to FIGS. 1 to 5 is that instead of the guide grooves 46 of FIG. 5 which are open on both end faces of the groove, guide grooves 146 on the outer circumference of the receiving ring 1 are formed axially parallel, which only have an open groove end face at the top, but a closed groove end face at the bottom. The guide grooves 146 extend to as much further down than the positioning grooves 30 such that for push-off of the doctor blade ring 3, a protrusion, or heel 136 of the magnet holding ring 2 or another, no magnets containing ring against the upper end face of the doctor ring press 3 and those from the receiving ring 1 can push away down.

Claims (11)

1. ink cup for pad printing machines, containing a receiving ring ( 1 ), which forms an ink cup jacket wall, an annular doctor edge ( 42 ) at the lower end of the pot, and a magnet retaining ring ( 2 ) with at least one magnetic body ( 52 ) for generating a doctor blade edge against Cliché of the tampon printing machine urging magnetic force, characterized in that a plug-and-turn connection of these two parts is formed between the receiving ring ( 1 ) and the magnetic holding ring ( 2 ), by means of which they can be axially plugged together and then by a relative rotary movement of less than 360 ° can be locked together. 2. Paint pot according to claim 1, characterized in that the plug-and-turn connection is formed by at least a pair of two grooves ( 30 ) in the outer peripheral surface of the receiving ring ( 1 ) and engaging therein, provided on the magnetic retaining ring projections ( 36 ), wherein the two grooves are arranged at a circumferential distance from each other and each have a longitudinal section for plugging together and a circumferential section for mutually locking the two parts. 3. Ink cup according to one of the preceding claims, characterized in that a squeegee edge ( 42 ) forming part ( 3 ) with the receiving ring ( 1 ) is releasably connected by an axial plug connection ( 16 ) that the receiving ring is offset in the circumferential direction in its outer peripheral surface to the plug-and-turn connection has at least two axially parallel guide grooves ( 46 ; 146 ) which are open at both ends, that the magnetic retaining ring ( 2 ) on the receiving ring ( 1 ) alternatively rotates with the plug-and-turn connection or, in the circumferential direction, relative thereto , can be brought into engagement with the guide grooves ( 46 ; 146 ) and can be pressed in the guide grooves up to beyond the axial locking position against the part ( 3 ) forming the squeegee edge in order to axially push it off the receiving ring ( 1 ). 4. Ink cup according to one of the preceding claims, characterized in that a plurality of magnetic bodies ( 52 ) are present and that these magnetic bodies are arranged on the magnetic holding ring ( 2 ) each with a circumferential distance from a diagonal line, which is offset by 90 ° to the doctor blade movement direction relative to a cliché runs, and that extend over this diagonal line peripheral portions without magnets. 5. ink cup according to one of the preceding claims, characterized in that a doctor blade edge ( 42 ) forming doctor blade ring ( 3 ) is plugged onto the lower end portion of the receiving ring ( 1 ) and an O-ring ( 16 ) is clamped radially between them, and that there is clearance between the doctor ring and the receiving ring, which allows the doctor ring on the O-ring radial and axial compensating movements relative to the receiving ring. 6. Ink cup according to claim 5, characterized in that the inner contour of the doctor ring ( 3 ) rests in the axial direction on the O-ring ( 16 ), so that the doctor ring has a defined damping behavior and compensating movements to compensate for unevenness of the cliché . 7. Paint pot according to one of the preceding claims, characterized in that it has a lid ( 6 ) and a removable bottom ( 7 ) so that it can be stored and sold filled with paint. 8. ink cup according to claim 7, characterized in that the bottom ( 7 ) and the squeegee edge ( 42 ) forming part ( 3 ) form an axial plug connection with each other. 9. Ink cup according to claim 8, characterized in that the bottom ( 7 ) has an annular fold or groove, in which the part having the doctor edge ( 3 ) can be inserted in a liquid-tight manner. 10. Paint pot according to one of claims 7 to 9, characterized in that the cover ( 6 ) has a vent opening ( 24 ) which can be optionally closed or opened. 11. Paint pot according to claim 10, characterized in that the vent opening ( 24 ) is formed in the region of an upwardly facing end face of the receiving ring ( 1 ), that in this end face a leading into the interior of the receiving ring vent channel ( 26 ) is formed, and that by rotating the cover relative to the receiving ring, the vent opening can either be closed by the end face or connected to the vent channel.