INK DRYING DEVICE FOR A PRINTING MACHINE

Abstract

 The invention relates to an ink drying device for a printing machine. The device comprising an outer casing (10) installed between two frame walls (51, 52) of a printing machine (50) and an inner casing (20) removably housed inside said outer casing (10), which is connected to an air discharge pipe of an air circulation device. The inner casing (20) is connected to an air supply pipe and has a longitudinal blow opening for blowing air against a substrate on an impression drum (53). There are suction openings between the outer and inner casings (10, 20) for drawing in air and solvent vapors that are conveyed towards the air discharge pipe. The outer casing (10) has an end opening at one end and the inner casing (20) is sized to be slidably inserted and removed in a direction substantially parallel to the axis of the drum (53).

Description

Technical Field

[0001] The present invention relates to an ink drying device applicable to a printing machine, and particularly to a flexographic printer, for drying ink recently printed on a substrate by a printing group of the printing machine.

Background of the Invention

[0002] Several types of printing machines are known, among which the flexographic printers, including one or more printing groups arranged for successively printing inks of different colors on a substrate supported on a rotary impression drum, and where downstream of each printing group there is a drying device suitable for drying ink recently printed on the substrate before reaching the next printing group, are included.

[0003] A known type of drying device comprises an outer casing fixed between two frame walls of the printing machine and an inner casing removably housed inside said outer casing. The outer casing has an air outlet connected to an air discharge pipe of an air circulation device and a longitudinal front opening facing the printed substrate on the impression drum of the printing machine, whereas the inner casing has an air inlet connected to an air supply pipe of the air circulation device and a longitudinal blow opening for blowing air through said front opening of the outer casing against the printed substrate. There are suction openings between the outer casing and the inner casing for drawing in air mixed with vapors generated by the drying of the ink, and suction passages for conveying the air and the vapors toward said air outlet.

[0004] The outer casing is supported on the bedplate such that it can pivot with respect to a horizontal axis between a working position in which the blow-in and suction openings are facing the impression drum and a substantially inverse cleaning and maintenance position, in which the inner casing can be inserted or removed in a radial direction through the front opening of the outer casing for performing cleaning and maintenance tasks. A drawback of this construction is the difficult access to the outer casing located between the frame walls of the printing machine. Another drawback is that every time the inner casing is removed, the outer casing loses its working position, which must be recovered again and then readjusted when the inner casing is reinstalled or replaced.

[0005] Patent ES-A-2112111 describes a printing machine of the aforementioned type, in which the ink drying devices are installed such that they can be removed toward one side of the bedplate of the machine by means of a sliding movement in a direction parallel to the axis of the impression drum so as to allow observing the impression drum, since in some printing machines, particularly in relatively small printing machines, observation of the drum is prevented by the printing groups and the ink drying devices. To that end, the entire set of casings of the ink drying device is guided by means of a bar parallel to the axis of the impression drum and comprises inlet and outlet sleeves which are coupled with air supply and discharge pipes when the set of casings is placed in the operating position. However, the drawback of losing the working position of the outer casing every time the set is removed persists, making it necessary to recover and readjust the working position again when the set of casing is reinstalled in the printing machine.

Disclosure of the Invention

[0006] The present invention contributes to solving the foregoing and other drawbacks by providing an ink drying device for a printing machine comprising an outer casing installed between two frame walls of a printing machine and an inner casing removably housed inside said outer casing. The outer casing has an air outlet prepared for being connected to an air discharge pipe of an air circulation device and a front opening facing a printed substrate on an impression drum of said printing machine. The mentioned front opening is elongated in a longitudinal direction parallel to the axis of the impression drum to substantially cover the entire width of the impression drum.

[0007] The inner casing has an air inlet prepared for being connected to an air supply pipe of said air circulation device and at least one longitudinal blow opening for blowing air through said front opening of the outer casing. The mentioned blow opening is also elongated in said longitudinal direction to substantially cover the entire width of the impression drum. Suction openings for drawing in air and ink drying vapors and suction passages for conveying the air and the ink drying vapors toward said air outlet, are arranged between the outer casing and the inner casing on both sides of the blow opening.

[0008] The outer casing has an end opening at one end and the inner casing is sized to pass through said end opening of the outer casing such that the inner casing can be inserted and removed axially, i.e., in a longitudinal direction parallel to the axis of the impression drum.

[0009] In one embodiment, the mentioned end opening of the outer casing is in communication with a passage opening formed in one of said frame walls of the printing machine, and the inner casing is sized also to pass through said passage opening of the frame wall, such that the inner casing can be inserted and removed in the longitudinal direction in/from an outer side of the frame wall.

[0010] The air inlet of the inner casing is located at a first end thereof adjacent to the end opening of the outer casing when the inner casing is inserted in the outer casing in a working position. The air inlet of the inner casing is further connected to a coupling sleeve projecting from the outer side of the frame wall when the inner casing is housed inside the outer casing, such that a preferably flexible air supply pipe can be easily connected to and disconnected from the coupling sleeve to facilitate the removal and placement of the inner casing.

[0011] In one embodiment, the inner casing has an anchor plate at said first end for being fixed to an outer side of the frame wall, and the air inlet is formed through said anchor plate. The blow opening is in the form of a longitudinal slit formed in a front wall of the inner casing, which has a cross-section which decreases from said first end adjacent to the air inlet to a second closed opposite end.

[0012] The air outlet of the outer casing is located in a rear wall thereof opposite the front opening. The air outlet is connected to a coupling sleeve located between the two frame walls of the printing machine, such that an air discharge pipe can be connected to said coupling sleeve in a virtually permanent manner given that the outer casing will remain fixed.

[0013] The outer casing has an anchor plate around the end opening for being fixed to an inner side of the frame wall in a position such that the end opening is in communication with the passage opening of the frame wall. The outer casing further has a cleaning and maintenance opening in said rear wall opposite the front opening, and accordingly located between the two frame walls. A cover is arranged for closing or opening said cleaning and maintenance opening.

[0014] Guiding means are arranged between the outer casing and the inner casing for guiding sliding movements of the inner casing with respect to the outer casing when the inner casing is axially inserted in and removed from the outer side of the frame wall.

[0015] The outer casing has longitudinal confinement lips located adjacent to outer sides of said suction openings and provided with front edges located very close to said impression drum of the printing machine although without contacting same, and adjustable fixing means allow adjusting the position of said confinement lips with respect to the impression drum and fixing them in the desired position.

[0016] With this construction, the inner casing can be removed and put in place again or replaced from an outer side of one of the frame walls without needing to change the position of the adjusted outer casing in relation to the impression drum.

Brief Description of the Drawings

[0017] The foregoing and other features and advantages will be better understood from the following detailed description of several embodiments in reference to the attached drawings, in which:

Figure 1 is a perspective view of a bedplate and other elements of a printing machine including a plurality of ink drying devices according to an embodiment of the present invention, where an inner casing of one of the drying devices is removed from a corresponding inner casing;

Figure 2 is a perspective view of the outer casing and the inner casing separated from one another in a cleaning and maintenance position, with an open cover, showing a front side thereof;

Figure 3 is a perspective view of the outer casing and the inner casing separated from one another in a cleaning and maintenance position, with the cover opened, showing an opposite rear side thereof;

Figure 4 is a perspective view of the outer casing and the inner casing coupled to one another in a working position, with the cover closed, showing a front side thereof with a cover opened;

Figure 5 is a perspective view of the outer casing and the inner casing coupled to one another in a working position, with the cover closed, showing an opposite rear side thereof with a cover opened; and

Figure 6 is a cross-section view of the ink drying device in the working position, with the cover closed.

Detailed Description of several Embodiments

[0018] First in reference to Figure 1, there is shown part of a printing machine 50 including a bedplate formed by first and second frame walls 51, 52 between which there is supported an impression drum 53 arranged for rotating with respect to a horizontal axis. A plurality of printing groups (not shown) for successively printing inks of different colors on a moving substrate supported on the impression drum while the latter rotates are arranged around said impression drum 53. Downstream of each printing group there is a corresponding ink drying device suitable for drying ink recently printed on the substrate before reaching the next printing group.

[0019] According to one embodiment of the present invention, each ink drying device comprises an outer casing 10 installed in a fixed position between the first and second frame walls 51, 52 and an inner casing 20 removably housed inside said outer casing 10. The first frame wall 51 has a plurality of passage openings 54 formed therethrough, each one adjacent to an end of one of the ink drying devices. The outer casing 10 of each ink drying device has an end opening 15 at a first end in communication with said passage opening 54 of the first frame wall 51 and the inner casing 20 is sized to pass through the corresponding passage opening 54 of the frame wall 51 and through said end opening 15 of the outer casing 10, such that the inner casing 20 can be axially inserted in and removed from an outer side of the frame wall 51.

[0020] Figure 1 shows the inner casing 20 of one of the ink drying devices removed from the outer casing 10 through the corresponding passage opening 54 of the frame wall 51. However, it must be indicated that the passage openings 54 could be omitted depending on the shape and arrangement of the first frame wall 51.

[0021] As shown in Figures 3 and 4, the outer casing 10 comprises a longitudinal front opening 12, which in an operating situation faces the printed substrate on the impression drum 53 of the printing machine 50, and a rear wall 17 in the form of a channel opposite the front opening 12. The outer casing 10 has the mentioned end opening 15 and an anchor plate 18 located around the end opening 15 at said first end. The anchor plate 18 serves for fixing the outer casing 10 to an inner side of the frame wall 51 in a fixed position by means of screws or the like, said position selected so that the end opening 15 is in communication with the corresponding passage opening 54 formed in the first frame wall 51. A second end of the outer casing 10 opposite the end opening 15 is closed by a wall 35 (Figure 2).

[0022] The outer casing 10 has guiding flanges 33 extending transversely from opposite edges of the mentioned rear wall 17 in positions adjacent to the front opening 12. Suction openings 13 are formed in said guiding flanges 33. In a central region of the mentioned rear wall 17 of the outer casing 10 there is an air outlet 11 connected to a coupling sleeve 16 which is located between the two frame walls 51, 52 when the outer casing 10 is fixed to the bedplate of the printing machine 50 in an operating position. The coupling sleeve 16 is configured for being connected to an air discharge pipe (not shown) of an air circulation device.

[0023] The suction openings 13 substantially cover the entire width of the impression drum 53 and are configured such that they provide a larger air passage opening the farther they are from the air outlet 11. In the embodiment shown, the suction openings 13 are narrower in the central region of the outer casing 10 and gradually widen as they approach the ends, and this is because the air outlet 11 is in the central region of the outer casing 10. The air outlet 11 could alternatively be located in other positions and the suction openings 13 could have other configurations.

[0024] The inner casing 20 comprises a front wall 25 and a wall in the form of a channel 26 fixed to a rear part of said front wall 25. At a first end of the inner casing 20 there is an anchor plate 24 which serves for fixing the inner casing to an outer side of the frame wall 51 around the passage opening 54 of the first frame wall 51 by means of screws or the like. At this same first end and through said anchor plate 24 there is formed an air inlet 21 connected to a coupling sleeve 23 projecting from the outer side of the first frame wall 51 when the inner casing 20 is housed inside the outer casing 10 in an operating situation (Figure 1). The mentioned coupling sleeve 23 is configured for being connected to an air supply pipe (not shown) of said air circulation device.

[0025] In the mentioned front wall 25 of the inner casing 20 there is formed a blow opening 22 in the form of a longitudinal slit, although the blow opening 22 could alternatively be of any other form or comprise a plurality of openings. In any case, the blow opening is configured for blowing drying air against the impression drum, covering the entire width thereof. The inner casing 20 has a second closed end opposite the air inlet 21, and the cross-section of the inner casing 20 gradually decreases from the first end adjacent to the air inlet 21 to the second closed opposite end.

[0026] Guiding channels 27 which are coupled to end edges of the mentioned guiding flanges 33 for guiding sliding movements of the inner casing 20 with respect to the outer casing 10 when the inner casing 20 is axially inserted in and removed from the outer side of the frame wall 51 are formed in opposite longitudinal edges of the front wall 25 of the inner casing 20. Nevertheless, it must be taken into account that the sliding movements of the inner casing 20 with respect to the outer casing 10 could alternatively be guided by other means different from the guiding flanges 33 and corresponding guiding channels 27, and the suction openings 13 could be formed in other locations that are not the guiding flanges 33.

[0027] In the rear wall 17 of the outer casing 10 there is a cleaning and maintenance opening 19 provided with a cover 30 connected in an articulated manner by means of hinges 36 and serving for closing or opening said cleaning and maintenance opening 19 with the aid of snap-fit closure devices 31. A perimeter gasket 32 is arranged for being pressed between the cover 30 and a portion of the rear wall 17 around the cleaning and maintenance opening 19 when the cover 30 is closed.

[0028] Figures 4, 5 and 6 show the outer and inner casings 10, 20 coupled to one another in the working position. Figures 4 and 5 show the respective anchor plates 18, 24 separated from one another by a distance corresponding to the thickness of the first frame wall 51 of the printing machine 50 (which has been omitted for greater clarity of the drawing). In this working position, the anchor plates 18, 24 of the outer and inner casings 10, 20 are fixed to the first frame wall 51 of the printing machine 50 and the mentioned end edges of the guiding flanges 33 of the outer casing 10 are coupled in the guiding channels 27 formed in the front wall 25 of the inner casing 20 (Figure 6).

[0029] Figure 6 schematically shows by means of arrows the circuit followed by the air moved by the air circulation device through the ink drying device in an operating situation, in which the outer and inner casings 10, 20 are coupled to one another and fixed to the first frame wall 51 of the printing machine 50. In this situation, the coupling sleeve 23 of the air inlet 21 of the inner casing 20 is connected to the air supply pipe (not shown) and the coupling sleeve 16 of the air outlet 11 of the outer casing 10 is connected to the air discharge pipe (not shown).

[0030] The air moved by the air circulation device enters a blow-in chamber defined by the wall in the form of a channel 26 and the front wall 25 of the inner casing 20 and is then expelled through the blow opening 22 against the printed substrate on the impression drum 53 of the printing machine 50 (not shown in Figure 6). After striking the substrate, the air mixed with solvent vapors generated by the drying of the ink is drawn through suction openings 13 which are located between the outer and inner casings 10, 20. The air mixed with solvent vapors enters a suction chamber defining suction passages 14 between the rear walls 17, 26 of the outer and inner casings 10, 20 and is finally discharged through the air outlet 11 and the corresponding coupling sleeve 16 toward the air discharge pipe (not shown) of the air circulation device.

[0031] The outer casing 10 has longitudinal confinement lips 34 located adjacent to outer sides of said suction openings 13. Front edges of the confinement lips 34 are located very close to the surface of the impression drum 53 of the printing machine 50 without actually contacting the substrate supported thereon, such that the confinement lips 34 prevent the air mixed with solvent vapors from being dispersed and being drawn through the suction openings 13.

[0032] The outer casing 10 preferably comprises adjustment means for adjusting the position of said confinement lips 34 in relation to the impression drum 53. In one embodiment, the outer casing 10 is fixed in a fixed position with respect to the bedplate and said adjustment means comprise adjustment and fixing means which allow certain movement of the confinement lips 34 with respect to the outer casing 10 when they are loosened for adjusting the position thereof, and when they are tightened they fix the confinement lips 34 to the outer casing 10 in a desired position.

[0033] In another alternative embodiment, the confinement lips 34 are fixed in fixed positions with respect to the outer casing 10 and the adjustment means comprise adjustment and fixing means which allow performing a certain adjustment movement for adjusting the outer casing 10 with respect to the bedplate when they are loosened for adjusting the position of the confinement lips 34, and when they are tightened they fix the outer casing 10 with respect to the bedplate in a desired position.

[0034] The position of the air outlet 11 and of the corresponding coupling sleeve 16 in the different outer casings 10 is variable and depends on the location of each ink drying device around the impression drum 53. For this reason, the position of the coupling sleeve 16 in the outer casing 10 shown in Figure 6 is different from the position of the coupling sleeve 16 in the outer casing 10 shown in Figures 2 to 4.

[0035] The air outlet 11 of the outer casing 10 is located in a rear wall 17 thereof opposite the front opening 12, and connected to a coupling sleeve 16 located between the two frame walls 51, 52 of the printing machine 50.

[0036] A person skilled in the art will devise modifications and variations based on the embodiments shown and described without departing from the scope of the present invention according as defined in the attached claims.

Claims

1. An ink drying device for a printing machine, of the type comprising an outer casing (10) installed between two frame walls (51, 52) of a printing machine (50) and an inner casing (20) removably housed inside said outer casing (10), wherein:

the outer casing (10) has an air outlet (11) connectable to an air discharge pipe of an air circulation device and a longitudinal front opening (12) facing a printed substrate on an impression drum (53) of said printing machine (50);

said inner casing (20) has an air inlet (21) connectable to an air supply pipe of said air circulation device and a longitudinal blow opening (22) for blowing air through said front opening (12) of the outer casing (10); and

suction openings (13) for drawing in air and ink drying vapors and suction passages (14) for conveying them toward said air outlet (11) are arranged between the outer and inner casings (10, 20),

characterized in that the outer casing (10) has an end opening (15) at one end and the inner casing (20) is sized to pass through said end opening (15) of the outer casing (10) and is inserted in and removed from the outer casing (10) by means of a movement in a direction substantially parallel to the axis of the impression drum (53).

2. The ink drying device according to claim 1, characterized in that said end opening (15) of the outer casing (10) is in communication with a passage opening (54) formed in one of said frame walls (51) of the printing machine (50) and the inner casing (20) is sized also to pass through said passage opening (54) of the frame wall (51) for being axially inserted in and removed from an outer side of the frame wall (51).

3. The ink drying device according to claim 1 or 2, characterized in that the air inlet (21) of the inner casing (20) is located at a first end thereof and connected to a coupling sleeve (23) projecting from the outer side of the frame wall (51) when the inner casing (20) is housed inside the outer casing (10).

4. The ink drying device according to claim 3, characterized in that the inner casing (20) has an anchor plate (24) at said first end for being fixed to an outer side of the frame wall (51), and the air inlet (21) is formed through said anchor plate (24).

5. The ink drying device according to claim 1 or 2, characterized in that the air outlet (11) of the outer casing (10) is located in a rear wall (17) thereof opposite the front opening (12) and connected to a coupling sleeve (16) located between the two frame walls (51, 52) of the printing machine (50).

6. The ink drying device according to claim 5, characterized in that the outer casing (10) has an anchor plate (18) around the end opening (15) for being fixed to an inner side of the frame wall (51) in a position in which the end opening (15) is in communication with the passage opening (54) of the frame wall (51).

7. The ink drying device according to claim 5 or 6, characterized in that the outer casing (10) has a cleaning and maintenance opening (19) in said rear wall (17) opposite the front opening (12) and a cover (30) for closing or opening said cleaning and maintenance opening (19).

8. The ink drying device according to any one of the preceding claims, characterized in that the outer casing (10) has guiding flanges (33) adjacent to the front opening (12) and the inner casing (20) has guiding channels (27) which are coupled with said guiding flanges (33) for guiding sliding movements of the inner casing (20) with respect to the outer casing (10) when the inner casing (20) is axially inserted in and removed from the outer side of the frame wall (51).

9. The ink drying device according to claim 8, characterized in that said suction openings (13) are formed in said guiding flanges (33).

10. The ink drying device according to claim 1, 2 or 9, characterized in that said suction openings (13) are configured such that they provide a larger air passage opening the farther they are from the air outlet (11).

11. The ink drying device according to any one of the preceding claims, characterized in that the outer casing (10) has longitudinal confinement lips (34) located adjacent to outer sides of said suction openings (13) and provided with front edges located very close to said impression drum (53) of the printing machine (50) without contact.

12. The ink drying device according to claim 11, characterized in that the outer casing . (10) comprises adjustable fixing means for adjusting the position of said confinement lips (34) and fixing them in an adjusted position.

Drawing