EP0645258A2 - Printing machine - Google Patents

Abstract

The invention relates to a printing machine having a cartridge (2) which contains a ribbon (7) and has two rotatably mounted cores (25,26,27,28) which are arranged with lateral spacing in a housing (18,19), the ribbon (7) being uncoiled from the one core (26), being moved past a print head (16) and being coiled onto the other core (28), and a through-bore (50) for inserting a receiving pin (52) of the printing machine (1) being formed on the housing (18,19). In order to be able to adjust the position of the ribbon (7) in an improved manner, it is proposed that the housing (18,19) bears against an adjusting ring (54) which can be displaced and fixed on the receiving pin (52). Alternatively or additionally it is recommended that a projecting guide plate (56) for the free strand (15) of the ribbon (7) is mounted pivotably on the housing (18,19), and that the length of the projecting cartridge arms (20,21) of the housing (18,19) is greater than that of the guide plate (56). <IMAGE>

Description

The invention relates to a printing machine with a cassette containing a tape, which has two rotatably mounted sleeves arranged in a housing at a lateral distance, the tape being unwound from one sleeve, guided past a printhead and wound onto the other sleeve, and a through hole for inserting a locating pin of the printing press is provided on the housing.

A printing press of the generic type has become known from DE 3723279 A1. The printer described there is suitable for the use of an ink ribbon cassette which contains a ribbon which is unwound from a sleeve during printing operation, carried out together with a recording medium between a thermal print head and a pressure roller and finally wound up on another sleeve. For optimal positioning of the cassette in the printer, guide pins are provided on the frame of the printing press, which extend along the geometric axes of the sleeves and engage in bores in the cassette. In order to create sufficient space for the printhead between the housing of the cassette and the free run of the ribbon, the latter is provided on its lateral edges with two protruding cartridge arms, on the end face of which a deflection element, ie a roller for the ribbon, is arranged. However, since the cassette arms are relatively short, is on the cassette arm adjacent to the sleeve on which the tape is wound, a long arm projecting outward is attached, at the tip of which a further deflecting element for the tape is seated. The free, usable strand of the ribbon is thus transported in a triangular way, only enough space being created between the housing and the strand by the protruding arm in order to be able to place the printhead in between.

A disadvantage of the known printing presses that no subsequent adjustment of the position of the cassette and the tape is possible, so that due to manufacturing tolerances of the dimensions of the cassette or tape, the optimal positioning of the tape relative to the print head is not guaranteed, so that - especially at higher printing speeds - not always good printing results.

The invention is therefore based on the object of developing a cassette of the type described at the outset in such a way that an optimal position of the tape within the printing press is ensured at all times.

Two alternatives to solve the problem are proposed below, one relating to the positioning of the cartridge in the housing and one to that of the ribbon relative to the printhead. Both solutions can of course be implemented together in one printing press.

To achieve the object, it is proposed according to the invention that the housing rests on an adjusting ring which can be displaced and fixed on the mounting bolt.

The invention makes use of the mounting bolts of the machine on which the cassette can be attached.

In addition, the cassette, as already from the prior art, is also attached to the drive shaft and the brake shaft for the two sleeves with the tape. Due to this three-point posture, the cassette or its respective working strand can be assigned quite correctly to other elements of the machine or to the printing roller of the printing press. Because the cassette rests on the adjusting ring, which in turn can be axially displaced and fixed on the locating pin penetrating the through bore of the cassette, its position along the geometrical axis of the locating pin, which usually runs parallel to that of the sleeves and to the pressure roller, can be varied and adjusted in order to achieve an optimal position of the belt. The adjusting ring can rest both on a surface facing the printing press and on an opposite surface of the cassette adjacent to the free end of the locating pin. The use of two adjusting rings, which immovably enclose the cassette between them, is also conceivable.

The cassette can consist of two identical, parallel housing halves, between which the sleeves are arranged. The locating pin then penetrates at least the through bore of one of the housing halves and the adjusting ring lies against this housing half. As an alternative to a cassette with two identical housing halves, one of them (in particular that facing away from the machine) can be enlarged in the middle in its upper area facing away from the printhead in order to make room for the through hole.

The through bore of the housing of the cassette can be formed by the bore of a bearing sleeve which is inserted into an opening in one half of the housing.

As a rule, the through hole is arranged on a transverse plane of symmetry of the cassette near the edge, while the usable, free strand of the band and the associated deflection elements are attached to the opposite end of the cassette.

For example, when using already printed recording media, it may be appropriate to print only a part of its width retrospectively - for example with an article number, designation or a price - while the remaining width is already labeled. If narrower ribbons are to be used to save printing tape costs, these can also be accommodated by the cassette according to the invention, the cassette being aligned via the adjusting ring which can be axially displaced and locked on the locating pin so that the narrower printing tape is in the area to be printed. The invention not only enables the use of cassettes of different widths, but also the assignment of the cassette to a very specific section of a printing roller that exceeds the width of the belt. It is also easily possible to mount two narrow cassettes next to each other and to print at the same time with two ribbons, in particular with different colors.

As an alternative to the teaching of claim 1, the problem underlying the invention can be in a printing machine with a cassette containing a tape, which is equipped with two cassette arms, at the free ends of which a deflecting element is provided for the free run of the tape, a print head between the Free strand of the tape and the cassette is arranged, and a baffle protruding forward over the housing for the tape is attached to the cassette arm, the sleeve is assigned, on which the tape is wound, solve that the guide plate is pivotally mounted on the housing and that the length of the cassette arms is greater than that of the guide plate.

The cassette is adapted to the special area of use insofar as it offers enough space for the print head of the printing press, which fits between the back of the usable, free run of the ribbon and the sufficiently long cassette arms arranged on both sides of the cassette housing. The space for the print head between the ink ribbon and the cassette is thus created by the fixed cassette arms. The invention now provides that in the area of at least the cassette arm, which is adjacent to the sleeve on which the tape is wound, there is an azimuthally pivotable guide plate for the tape, which protrudes forward over the housing. With the help of this baffle you can pull the working strand a little further out of the cassette at the relevant point. The guide plate is shorter than the cartridge arms and has the primary task of increasing the wrap angle of the ribbon around the thermal print head. Because of the larger angle, the ink ribbon remains in contact with the recording medium to be printed for a longer time and, in particular in the case of thermal printers, enables the dyes to solidify before the recording medium is removed from the ribbon. At smaller angles, on the other hand, the tape would be pulled off the recording medium at high printing speeds, although the dyes have not yet hardened (dried), so that they would at least partially be removed again with the ink ribbon, with the print quality suffering. Since the guide plate can be pivoted azimuthally (about an axis running parallel to the pressure roller), the cassette can also be easily inserted with the guide plate pivoted back; it is then adjusted in such a way that an optimal printed image is produced, the short length making it easier to set the optimum angle. As a rule, the guide plate is attached to the associated bolt-shaped deflection element.

It is particularly advantageous if the guide plate at most protrudes laterally over the housing in a pivoted-back position. When inserting the cassette into the printing machine, there is a risk that the working strand of the tape will protrude beyond the associated free arm end to such an extent that it will get caught on the printing roller and damage is to be feared. In order to avoid this, the guide plate is brought into a swiveled-back position in which the tape at most protrudes somewhat laterally over the cassette arm in question, but this is relatively unproblematic with regard to the risk of damage when inserting the cassette. Otherwise, you can of course make the arm correspondingly wide, so that the band does not protrude outwards in the ineffective rotational position of the guide plate. For simple operation, however, it makes more sense if the cassette in this regard is designed as in the exemplary embodiment.

If the cassette is a reversible cassette, which is turned over and used again after the passage of the entire belt, the other cassette arm is now assigned to the printing roller and, consequently, a deflection element is now required there. You can now either provide a baffle on each cassette arm or you can make the baffle removable.

Further configurations of the printing press as well as the resulting effects and advantages result from the following description of an embodiment.

Figur 1

eine Seitenansicht einer Druckmaschine mit eingesetzter Kassette;

Figur 2

eine Ansicht einer geringfügig abgewandelten Kassette;

Figur 3

einen Ausschnitt aus Figur 2 mit dem Leitblech in einer anderen Stellung;

Figur 4

einen Schnitt gemäß der Linie IV-IV der Figur 2;

Figur 5

eine Ansicht der Kassette der Figur 1;

Figur 6

einen Schnitt gemäß der Linie VI-VI der Figur 5;

Figur 7

einen Schnitt durch die Kassette der Figur 2, wobei die Schnittführung derjenigen der Figur 5 entspricht;

Figur 8

in vergrößertem Maßstab eine Ansicht des Grundkörpers einer der beiden Hülsen;

Figur 9

einen Längsmittelschnitt durch den Grundkörper der Figur 8;

Figur 10

eine Ansicht des anderen Grundkörpers der Hülsen;

Figur 11

einen Längsmittelschnitt durch den Grundkör per der Figur 10;

Figur 12

in der Ansicht die zu den Hülsen gehörende Antriebswelle; und

Figur 13

eine Ansicht der Antriebswelle der Figur 12 von rechts.

The drawing shows two embodiments of the invention. Here represent:

Figure 1

a side view of a printing press with an inserted cassette;

Figure 2

a view of a slightly modified cassette;

Figure 3

a section of Figure 2 with the baffle in a different position;

Figure 4

a section along the line IV-IV of Figure 2;

Figure 5

a view of the cassette of Figure 1;

Figure 6

a section along the line VI-VI of Figure 5;

Figure 7

a section through the cassette of Figure 2, the cut corresponds to that of Figure 5;

Figure 8

an enlarged view of the base body of one of the two sleeves;

Figure 9

a longitudinal central section through the base body of Figure 8;

Figure 10

a view of the other base body of the sleeves;

Figure 11

a longitudinal central section through the Grundkör by Figure 10;

Figure 12

in the view the drive shaft belonging to the sleeves; and

Figure 13

a view of the drive shaft of Figure 12 from the right.

The cassette 2 is inserted into the printing press 1 approximately perpendicular to the image plane. A rear wall 3 of the printing press is penetrated by two externally toothed shafts arranged at a lateral distance, for example one shaft 4 being a drive shaft connected to a drive motor, while the other shaft 5 can be a brake shaft connected to a slip clutch. The side spacing of the two shafts 4 and 5 corresponds to the hole spacing 6 of the cassette 2.

The cassette 2 receives a tape 7, which is located on a sleeve 8, preferably a cardboard sleeve. If this band 7 is to run in the direction of arrows 9, 10 and 11 of FIG. 2, the band 7 with the sleeve 8 is initially assigned to the brake shaft 5. If the drive shaft 4 is driven, it is unwound from the sleeve 8 and wound onto a further sleeve 12 which is penetrated by the drive shaft 4. The belt 7 is deflected via deflection elements 13 and 14 at the lower end of the cassette in FIG. The section located between these deflection elements 13 and 14 forms the working usable strand 15 of the belt 7. It is passed between a print head 16 of the printing press 1 and a printing roller 17 (FIG. 1).

Essential components of the cassette 2 are two parallel housing halves 18 and 19. They have one essentially C-shaped shape, so that cassette arms 20 and 21 arise. The two deflection elements 13 and 14, which are pointed bolts at the free end according to FIG. 7, for example, are assigned to the free arm ends. At the transition to each arm 20 and 21 there are a further deflecting element 22 or 23 for the band 7. Also in this respect, according to FIG. 7, these are pointed bolts, which are preferably firmly connected to the housing half 18 by means of one screw each, ie that half of the housing which is assigned to the rear wall 3. The tape 7 can either be unwound according to the illustration with solid lines in FIG. 2 or according to the illustration with the dashed line 24 in FIG. 2. In this way, the cassette 2 can be used both for an externally wound ribbon or tape 7 and for an internally wound ribbon .

Further important elements of the cassette 2 are at least one sleeve per shaft 4 or 5. In all exemplary embodiments, however, two short coaxial sleeves 25 and 26 or 27 and 28 are provided per shaft 4 and 5 instead of, for example, a long sleeve. Each pair of sleeves 25, 26 and 27, 28 receives a tape sleeve 8 and 12, respectively. The sleeves 25 and 27 are each rotatably supported in the first housing half 18 and the sleeves 26 and 28 in the second housing half 19. Each sleeve 25 to 28 is formed in two parts according to FIG. 7, for example, which facilitates its mounting on the housing 29. According to the above, this housing 29 essentially consists of the two housing halves 18 and 19 and the deflection elements 13, 14, 22, 23 formed by bolts.

The housing half 19 can be pulled off in the direction of arrow 30 from the bolts 13, 14, 22, 23 and is held on the free bolt ends only by clamping. Serve for exact positioning of the housing half 19 the deflection elements 13, 14, 22 and 23, which are each held by a sleeve, preferably plastic sleeve 31 to 34, at each push-through opening of the second housing half 19.

As can be seen, for example, from FIG. 7, all sleeves 25 to 28 are formed in two parts and each consist of a sleeve-shaped base part 35 and an annular securing part 36 that can be connected to it 18 inserted. The annular securing part 36 is pushed onto the respective projecting end and axially secured by means of a securing element 39, preferably a snap ring. Each sleeve-shaped base element 35 lies with an outer collar 40 on the inner surface of the associated housing half 18 or 19. Opposite is the ring-shaped securing part 36 on the outside of each housing half 3 or 19, whereby the axial securing on the housing half 3 or 19 is achieved.

It can be seen in particular from FIGS. 9 and 11 that the base part 35 is reduced in batches, the ring-shaped securing part 36 being pushed onto the smaller sleeve-shaped section 41 according to FIG. 7 and the securing element 39 being latched thereon. This section 41 can be extended into the sleeve interior according to FIGS. 9 and 10. In any case, the smaller sleeve-shaped section 41 of the first sleeves 26 and 28 has an internal toothing 42 which corresponds to the external toothing 43 of the shafts 4 and 5, respectively. Such an internal toothing could be attached to all the sleeve-shaped base parts 35, but the exemplary embodiments provide that the sleeve-shaped base parts 35 of the second sleeves 25 and 27 have a bore 44 with a smooth inner surface (FIG. 9). This is the basis for them free ends of the teeth of the teeth 43 of the shafts 4 and 5.

Furthermore, it can be seen from FIGS. 9 and 11 that the sleeve-shaped base parts 35 are provided with longitudinal slots 45 in the region of their larger diameter, so that resilient tongues 46 are formed. It can be seen from FIGS. 8 and 10 that the resilient tongues 46 each carry a radially projecting holding element 47 on the outside, preferably in the form of a small radial strip. This improves the non-positive and positive connection of the sleeves 25 to 28 with the band sleeves 8 and 12. In order to maintain the clamping between the tongues 46 and the band sleeves 8 and 12, the tongues 46 become permanent by a snap ring (not shown) inserted into an inner groove 59 pushed radially outwards. According to FIG. 10, a larger number, for example twice the number of receiving grooves 48 for the teeth 43, can be provided.

The cassette 2 of FIG. 7 is intended for relatively wide tapes 7. However, it is also easily possible to insert narrower tapes 7 into this cassette 2, because the second housing half 19 is displaceably mounted on the bolt-like deflection elements 13, 14, 22 and 23 and is held in every displacement position by friction. If the second housing half 19 is moved from its position in FIG. 7 to the left towards the first housing half 18, the free bolt ends protrude beyond the housing half 19 on the right. If for some reason this is unacceptable or at least not desired, shorter bolts can also be used instead, which is easily possible because they are screwed onto the first housing half 18. FIG. 6 shows an embodiment with short bolts or deflection elements 13, 14; 22, 23. In principle, however, it has the same structure as the cassette 2 of FIG. 7. However, there is a slight difference in that the housing half 19 formally deviates from that of the cassette according to FIG. 2 at its upper end. The housing half 19 is provided at its upper end with a bulge 49 on which an opening 50 is located. A bearing sleeve 51, which preferably consists of plastic, is pressed into this. When this cassette 2 is inserted into the printing press 1, a locating pin 52 attached to the rear wall 3 of the printing press 1 engages in the bore of the bearing sleeve 51. The cassette 2 of FIGS. 5 and 6 is securely fixed in the printing press 1 by means of this mounting bolt 52 and the two shafts 4 and 5. To better slide the cassette 2, the locating pin 52 is slightly tapered at its free end. The same applies according to the drawing for shafts 4 and 5. Otherwise, the shaft of shafts 4 and 5 each penetrates a bearing bush 53 of wall 3. It is used for axial and radial mounting.

Because the cassette 2 in FIG. 6 is narrower than the cassette 2 in FIG. 7, the thickness of which corresponds approximately to the length of the shafts 4 and 5, insofar as they protrude beyond the wall 3, the exact position of the cassette 2 relative to the printing press 1 must be determined or specify the wall 3 by suitable means. One possibility is that an adjusting ring 54 with a clamping screw 55 is pushed onto the mounting bolt 2. It is easy to see that by moving the adjusting ring 54 to the left, that is to say against the wall 3, the stop formed by this is shifted and the cassette 2 thereby moves closer to the wall 3. On the other hand, it can also be easily imagined from FIG. 6 that two cassettes 2 are placed next to one another in the printing press 1, each of which can be loaded with a different, in particular differently colored, band 7. It is also straightforward possible to first print any labels or the like with the cassette 2 in the position shown in FIG. 6 and then to move the cassette 2 all the way to the left in order to apply a second print to the side of the printed product.

In the area of at least one of the deflecting elements 13, 14 in the exemplary embodiment in FIG. 2 on the deflecting element 14 there is a guide plate 56 which is pivotably mounted on this deflecting element 13 or 14 in the sense of the double arrow 57. It maintains its respective pivot position, preferably by means of a clamping action. The working position of the guide plate 56 can be seen in FIG. 2. The usable strand 15 is pulled out over the free end of the cassette arm 21. If, on the other hand, the guide plate 56 is brought into the rotational position shown in FIG. 3, the strand 15 does not protrude downward beyond the free ends of the housing 29, but at most laterally beyond the outside of the cassette arm 21 into the printing press 1 is not relevant with regard to a risk of damaging the tape. However, it can be seen from FIG. 2 that by pulling the left end of the usable strand 15 out of the cassette 2, the printing roller 17 is gripped at a somewhat larger angle, which is advantageous for printing at high ribbon speeds.

Because the cassette 2 is symmetrical with respect to a longitudinal center plane 58 (FIG. 5), it can be used as a reversible cassette, ie after the tape 7 has been completely run through, it is simply turned over in the manner known for audio cassettes and the tape 7 is run through again completely. In this case, a guide plate 56 is also required on the cassette arm 20. You can now either attach a guide plate 56 to each of the two cassette arms 20 and 21 or make the guide plate 56 removable so that remove it from the cassette arm 21 and slide it on the cassette arm 20 after turning the cassette 2.

The cassettes 2 described are easy to manufacture, just as simple but can also be dismantled. The cassette 2 can in particular be easily introduced into the printing press 1 by the described design of the shafts 4 and 5 and the associated sleeves 25 to 28 in a self-finding mechanism, to which above all the double number of receiving grooves 48 contributes.

Claims (10)

Printing machine with a cassette (2) containing a band (7), which has two rotatably mounted sleeves (25, 26, 27, 28) arranged in a housing (18, 19) at a lateral distance, the band (7) from one of the sleeves (26) is unwound, guided past a print head (16) and wound onto the other sleeve (28) and a through hole (50) on the housing (18, 19) for inserting a locating pin (52) of the printing press (1) is attached, characterized in that the housing (18, 19) rests on an adjusting ring (54) which can be displaced and fixed on the locating bolt (52). Printing machine according to claim 1, characterized in that the housing of the cassette (2) consists essentially of two parallel housing halves (18, 19), between which the sleeves (25, 26, 27, 28) are arranged. Printing machine according to claim 1 or 2, characterized in that the through bore (50) is formed by the bore of a bearing sleeve (51) which is inserted into an opening in a housing half (19). Printing machine according to one of claims 1 to 3, characterized in that the through hole (50) is arranged on a transverse plane of symmetry (58) of the cassette (2) and is located at a cassette end (49), while deflection elements (13, 14; 22, 23) for the free strand (15) of the tape are arranged at the opposite end of the cassette (2). Printing machine according to one of claims 1 to 4, characterized in that the usable width of a print line of the print head (16) and / or the guides for a record carrier is greater than the width of the tape (7), in particular a multiple thereof. Printing machine with a cassette (2) containing a band (7), which is equipped with two cassette arms (20, 21), at the free ends of which a deflecting element (13, 14) for the free run (15) of the band (7) is provided, a print head (16) is arranged between the free strand (15) of the tape (7) and the cassette (2), and a guide plate (56) for the tape (projecting forward over the housing (18, 19)) 7) is fastened to the cassette arm (21) which is assigned to the sleeve (28) on which the band (7) is wound, characterized in that the guide plate (56) is pivotably mounted on the housing (18, 19), and that the length of the cassette arms (20, 21) is greater than that of the guide plate (56). Printing machine according to claim 6, characterized in that the guide plate (56) in a pivoted-back position at most projects laterally over the housing (18, 19). Printing machine according to claim 6 or 7, characterized in that the cassette (2) can be inserted when the guide plate (56) is pivoted back. Printing machine according to one of claims 6 to 8, characterized in that in the case of a reversing cassette, a guide plate (56) is assigned or can be assigned to each deflecting element (13, 14). Printing machine according to one of claims 6 to 9, characterized in that the guide plate (56) can be removed and plugged onto the opposite deflecting element (13 or 14).

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