GB2035213A

GB2035213A - Printing machine

Info

Publication number: GB2035213A
Application number: GB7940626A
Authority: GB
Original assignee: KORTHOFAH B
Current assignee: KORTHOFAH B
Priority date: 1978-11-29
Filing date: 1979-11-23
Publication date: 1980-06-18
Also published as: DE2947405A1; JPS5574878A; FR2442720A1; FR2442720B1; NL171037B; NL7811689A; GB2035213B; NL171037C

Abstract

A printing machine comprises a movably supported printing means (1, 4, 5, 6) an inking means (7, 8), and a metering device (9) actuable by motion of the printing means so as to cause a metered amount of ink to be supplied periodically from an ink reservoir (13) to the inking means. Preferably the metering device comprises a round cam having a number of equally spaced projections around its periphery for producing a controlled flow of ink through a flexible tube. <IMAGE>

Description

SPECIFICATION Printing machine The invention relates to a printing machine comprising a movably supported printing means and an inking means.

In prior-art printing machine of this type, the inking means must be regularly provided with ink during use, since the inking means can only contain a limited amount of ink. The inking means has so far been manually refilled by an operator, which creates the possibility of a shortage of ink occurring before refilling, causing the legibility of the signs provided on the printing means to be impaired, while the inking means may contain an excess of ink immediately after been refilled.

Therefore, an object of the invention is to provide a printing machine of the above kind, in which these problems have been solved in an effective but nevertheless simple manner.

According to the invention, such a printing machine is characterized by a metering device which is actuable by a motion that is derived from the motion of the printing means, causing a metered amount of ink or the like to be supplied periodically from an ink reservoir to the inking element.

During operation of the printing machine, the ink is thus supplied automatically, without requiring the intervention of an operator, to the inking means, in such a manner that constant inking of the printing means is ensured. The ink reservoir can contain a large amount of ink which is sufficient for a prolonged period of use.

Since the operation of the metering device is derived from the motion of the printing means, the printing machine can be simple in design and construction, allowing itto be manufactured at relatively low costs.

The printing means may, for example, be pivotmounted, against the action of a spring, on a fixed shaft, thus performing a pivotal motion during the printing operation. According to the invention, the metering device is then mounted on the same shaft and actuatable by the pivotal motion.

Further, the printing means of the printing machine may be rotatably supported, wherein an eccentric disc for establishing an initial position of the printing means is mounted on the shaft of the printing means. According to the invention, the metering device is then actuated by this eccentric disc.

The printing means may also be driven by an air cylinder, in which case, according to the invention, the metering device is also actuable by the air cylinder.

According to a favourable embodiment of the invention, the metering device comprises a housing which accommodates a flexible ink conduit, one end of which is coupled to the ink reservoir, the other end being connected to the inking means, and a dispensing means which is movably mounted in the housing and has at least one projecting part substantially occluding the ink conduit, the projecting part of the dispensing means being dispiacable periodically through a certain distance with respect to the ink conduit.

Since the projecting part of the dispensing element is displaced in each instance through a certain distance with respect to the ink conduit, a specific amount of ink depending on the displacement, is pressed periodically towards the inking element.

According to the invention, the dispensing means can be constituted by a round disc which is rotatably supported in the housing and which possesses a number of projections located at mutally equal distances, the flexible ink conduit being concentric with the disc over an arc length of about 180 , in such a manner that the projections of the disc can occlude the concentric part of the ink conduit.

A simple embodiment of the invention is characterized in that the ink conduit is constituted by a flexible tube which passes through the housing and which is connected at one end of the inking means and at the other end to the ink reservoir.

The round disc preferably possesses two flanges, between which the concentric part of the ink conduit is arranged, the projections of the round disc being constituted by rolls which are rotatably supported between the flanges. This causes the wear of the ink conduitto be restricted to a minimum.

According to the invention, it is advantageous if the dispensing means is operable by means of a manually operated dispensing knob. If the inking means does not yet contain any ink at the start of an operating cycle, a certain quantity of ink can then be manually supplied to the inking means.

The invention will be explained hereinafter on the basis of the drawing, which illustrates some embodiments of the invention.

Fig. 1 is a diagrammatic top view of a first embodiment of the printing machine according to the invention.

Fig. 2 is a diagrammatic side view of a second embodiment of the printing machine according to the invention.

Fig. 3 is a diagrammatic sectional, and in part elevational, view of a third embodiment of the printing machine according to the invention.

Fig. 4 is a sectional view of the metering device used with the printing machine according to Figs. 1 and 2.

Fig. 5 is a sectional view of the metering device according to Fig. 4 in the area of the ink conduit.

Fig. 6 is a sectional view along the line VI-VI in Fig.

4.

Fig. 7 is a sectional view of the metering device used with the printing machine according to Fig. 3.

Fig. 8 is a sectional view along the line VIII-VIII in Fig.7.

Fig. 1 shows a printing machine 1 which is pivotmounted against the pressure of a spring on a shaft 2. The shaft 2 is fixed on a supporting plate 3, mounted, for example, on the frame of a belt conveyer (not shown). The printing machine 1 comprises a bearing plate 4 upon which a rotary text roll 5 is mounted which is driven by a product 6 which, having been positioned on the conveyer belt, is passed along the printing machine 1.

The text roll 5 drives a rotary ink-distributing roll 7 which delivers the ink from an ink holder 8 to the text roll 5. The ink-distributing roll 7 and the ink holder8 are also mounted on the bearing plate 4. For uniform inking of the text roll 5, it is important for the amount of ink contained in the ink holder not to vary too much during operation of the printing machine 1.

To this end, a metering device 9 for the ink is pro vided which is mounted on the shaft 2 by means of a connector 10. The metering device 9 comprises a housing 11 and an actuating pin 12 which is slidably supported therein. The actuating pin 12 is controlled by the pivotal motion of the printing machine 1 occurring during the printing of the product 6, as shown schematically in the figure. This causes the metering device 9 to dispense during each printing cycle a predetermined amount of ink from an ink reservoir 13 to the ink holder 18. To this end, the ink reservoir 13 is connected by a flexible tube 14 to the metering device 9, while the metering device 9 is connected by a flexible tube 15 to the ink holder 8. A stop cock 16 is provided between the tube 14 and the metering device 9.

Fig. 2 is a side view of a printing machine 17 also comprising a metering device 9. The printing machine 17 has a rotary text roll 18 which is rotatably supported on a shaft 19 between the legs of a U-profile section 20. For the sake of clarity, the leg 21 seen in the drawing has been in part broken away so as to show a disc 22 which is mounted eccentrically on the shaft 19. This disc 22 establishes an initial position of the text roll 18 and at the same time actuates the actuating pin 12. A rotary roll 23 is mounted on the end of this actuating pin 12 in order to prevent friction between the actuating pin 12 and the eccentric disc 22.

The metering device 9 is again mounted by means of a connector 10 on a shaft 24, which in tu rn is mounted on the leg 21 of the U-profile section 20. As in the case of the printing machine 1 of Fig. 1, the metering device 9 is rotatably mounted on the shaft 24, which corresponds to the shaft 2, allowing the distance through which the actuating pin 12 can be displaced in the course of each printing cycleto be adjusted, so that the amount of ink dispensed can be controlled.

The tube 15 which connects the metering mechanism 9 to the ink holders 25, 26 opens into a distri butor 27 which uniformly distributes the ink supplied along the lengths of the ink holders 25,26. The ink holders 25, 26 together with an ink-distributing roll 28 are rotatably supported in a tray 29 and are driven, through the intermediate ink-distributing roll 28, by the text roll 18. The text roll 18 is driven buy a product 30, which in this case is passed underneath the printing machine 17 on a conveyer belt (not shown).

Fig. 3 diagrammatically shows a printing machine 31 having a housing 32 and a printing head 33. The printing head 33 is driven by an air cylinder 34 comprising a piston rod 35 upon which a driving element 36 is mounted. The driving element 36 operates through an intermediate bracket (not shown) which is rotatably supported in the housing 32 - a mounting 37 upon which the printing head 33 is fitted.

The printing machine 31 comprises a metering device 38 having a housing 39 and an actuating pin 40 which is pivotally supported in the housing 39.

The actuating pin 40 is operated for part of the stroke of the piston rod 35 by this piston rod 35, said part being adjustable by mounting the metering device slidably on the housing 32 of the printing machine 31. This measure again allows the amount of ink dis pensed to be controlled.

The ink is supplied through the tube 14 from the ink reservoir 13 to the metering device 38, which feeds the inkthrough the tube 15 to an inking means 41, which bears an inking pad 42 on its underside.

The tube 15 is slid on a nipple 43 which connects to a duct 44 formed in the inking means 41. This duct 44 opens into an annular groove 45 which extends along the periphery of the inking pad 42 to provide a uniform distribution of the ink throughout the inking pad 42.

In the position shown of the printing head 33, the text provided thereon is inked by the inking pad 42.

In the schematically indicated position, the product which is being passed along the printing machine 31 is provided with a text. The printing head 33 is spring-supported on the mounting 37, allowing the printing head 33 to move over a short distance towards the product when the printing position is reached. The piston rod 35 of the air cylinder 34 is abruptly braked for this purpose by a fixed blocking piece 46 when the printing position is reached. In this manner, continuously moving products can be printed.

Normally, with such continuously moving products it is desired to use a rapidly drying ink. In prior-art printing machines of this type, this caused the problem of the surface of the inking pad 42 drying out even after a short down time as a result of the fact that the inking means 41 served at the same time as the ink reservoir, so that the inking pad 42 was constantly wetted. This problem is solved by using the metering device 38, since no ink is dispensed to the inking pad 42 during the down times of the printing machine 31.

In orderto prevent a lack of ink in the inking pad 42 during the first printing cycles after a prolonged down time of the printing machine 31, the metering device 38 is provided with a dispensing knob 47. A certain amount of ink can be supplied manually to the inking means 41 by means of the dispensing knob 47. The aforedescribed metering device 9 is also provided with such a dispensing knob 47.

Figs. 4 and 5 are two sectional views of the metering device 9, the section according to Fig. 4 being a top view of a dispensing means 48 rotatably supported in the housing 11 together with accessories.

The dispensing means 48 is mounted on a shaft 49, one end of which bears a one-way coupling 50. A coupling plate 51, connected by a reset spring 52 to the actuating pin 12, is mounted upon this coupling 50. Further, the actuating pin 12 has a projection 53 which, during the return stroke of the actuating pin 12, engages the coupling plate 51, returning it to the rest position shown.

As shown in the sectional view according to Fig. 6, the dispensing means 48 comprises a round disc 54 with two flanges 55 and 56. The two flanges 55 and 56 enclose three rotary rolls 57, of which in any posi tion of the dispensing means 48 always one occludes a flexible ink conduit 58, which is concentric with the dispensing means 48 over an arc length of about 1800. In the embodiments shown in the drawing, the ink conduit 58 is constituted by the tube 15 which extends, respectively, to the ink holder 8, to the ink holders 23,24 and to the inking element 41.

When the actuating pin 12 is pressed in by a motion which is derived from a motion of the printing means of the printing machine involved, the coupling plate 51 is carried along by the reset spring 52. The coupling 50 is active in this direction of motion, so that the disc 54 with the rolls 57 is also rotated. The rolls 57 are accordingly displaced with respect to the flexible ink conduit 58, which causes a quantity of ink, depending on the amount of rotation of the disc 54, to be pressed forwards through the ink conduit 58 and to be dispensed to the ink holder or to the inking pad.

The amount of rotation of the disc 54 depends primarily on the distance over which the actuating pin 12 is pressed in. As indicated hereinabove, this distance can be controlled by displacing the metering device 9 in its entirety with respect to the printing machine involved. A second possibility of controlling the amount of ink dispensed is obtained by providing an adjusting member 60, which is screwed in the wall 59 of the housing 11 and which acts as a stop for the coupling plate 51. When the coupling plate 51 strikes against the adjusting member 60 during the operation stroke of the actuating pin 12, the dispensing means 48 will also be incapable of further motion.

In the course of the further operating stroke of the actuating pin 12, the reset spring 52 will be extensively stretched, enabling it to return the actuating pin 12 to its initial position during the return stroke, thereby also returning the coupling plate 51 to its initial position as soon as the projection 53 again engages the coupling plate 51. The other end of the shaft 49 also bears a one-way coupling 61 which blocks the disc 54 during the return motion of the coupling plate 51. The dispensing knob 47 is also mounted on this end of the shaft 49. The space between the dispensing knob 47 and the housing 11 is sealed by means of a seal 62.

The metering device 38, two sections which are shown in Fig. 7 and 8, is substantially similar to the metering device 9 described hereinabove. Corresponding parts are indicated by the same reference numbers, and their description is not repeated.

In the metering device 38, the dispensing means 48 is operated through a delay means by the actuating pin 40. The actuating pin 40 is connected to a disc 63 which is mounted on a shaft 65 by means of a one-way coupling 64. The other end of the shaft 65 is supported in the housing 39 by means of a one-way coupling 66 active in the opposite direction. An eccentric disc 67, which actuates a pin 68, is mounted on the shaft 65. The pin 68 is connected to a circular plate 69 which corresponds to the coupling plate 51 and which is fitted on the coupling 50.

The coupling plate 69 is provided with two cams 70 and 71, of which the cam 70 co-operates with the adjusting member 60, while the cam 71 is connected by a tension spring 72 to the actuating pin 40. The tension spring 72 every time returns the actuating pin 40 and the coupling plate 69 to the rest position.

The adjusting member 60 blocks the coupling plate 69 of the metering device 38 during the return motion of the coupling plate 69.

The actuating pin 40 rotates the shaft 65, and thereby the eccentric disc 67, through a given angle in the course of each printing cycle, the number of printing cycles required for each complete revolution being a function of the adjustment of the metering device 38 with respect to the printing machine involved. Each revolution of the eccentric disc 67 causes the dispensing element 48 to be operated, the amount of ink dispensed being adjustable by means of the adjusting member 60.

It is to be noted that it is also possible to combine the metering device 9 with the printing machine 31, and to provide the printing machines 1 and 17 with the metering device 38.

Claims

1. Printing machine, which comprises a movably supported printing means, an inking means, and a metering device actuable by motion of the printing means so as to cause a metered amount of ink to be supplied periodically from an ink reservoir to the inking means.

2. Printing machine according to claim 1, wherein the printing means is pivotally mounted and resiliently biassed on a fixed shaft such as to perform a pivotal motion during printing operation: the metering device being mounted on the same shaft and actuable by the pivotal motion.

3. Printing machine according to claim 1 or 2, wherein the printing means is rotatably supported on a shaft, and an eccentric disc for establishing an initial position of the printing means is also mounted on this shaft, the metering device being actuatable by the eccentric disc.

4. Printing machine according to any preceding claim wherein the printing means is drivable by an air cylinder, and the metering device is also actuable by the air cylinder.

5. Printing machine according to any preceding claim, wherein the metering device dispenses a metered amount of ink during each printing cycle.

6. Printing machine according to any preceding claim wherein the metering device comprises a housing which accommodates a flexible ink conduit, one end of which is coupled to the ink reservoir, the other end being connected to the inking means, and a dispensing means which is movably mounted in the housing and has at least one projecting part substantially occluding the ink conduit, the projecting part of the dispensing means being displacable periodically through a certain distance with respect to the ink conduit.

7. Printing machine according to claim 6, wherein the dispensing means comprises a round disc which is rotatably supported in the housing and which possesses a number of projections arranged at mutally equal distances, the flexible ink conduit being concentric with the disc over an arc length of substantially 1800, in such manner that the projections of the disc can occlude the concentric part of the ink conduit.

8. Printing machine according to claim 7, wherein the round disc is mounted on a shaft which is rotatably supported in the housing, each end of said shaft being provided with one-way coupling, one of said couplings being ficed to the housing, the other coupling bearing a coupling plate operable by means of an actuating pin which protrudes outside the housing.

9. Printing machine according to claim 8, wherein the actuating pin is slidably supported in the housing, the coupling plate being connected by way a reset spring to the actuating pin, the actuating pin having a projection which, during the return stroke, returns the coupling plate to its initial position.

10. Printing machine according to claim 8, wherein the actuating pin operates the dispensing means through a delay means.

11. Printing machine according to claim 10, wherein the actuating pin is coupled with a shaft which is rotatably supported in the housing by means of two-way couplings, an eccentric disc being mounted on this shaft, the coupling plate being operated by the eccentric disc through a pin.

12. Printing machine according to claim 11, wherein a tension spring is fitted between the actuating pin and the coupling plate.

13. Printing machine according to any of claims 6 to 12, wherein the dispensing means is controlled by means of a manually operable dispensing knob.

14. Printing machine according to any of claims 6 to 13, wherein the ink conduit comprises a flexible tube which passes through the housing, one end of this tube being connected to the inking means and the other end to the ink reservoir.

15. Printing machine according to any of claims 7 to 14, wherein the round disc comprises two flanges, between which the concentric part of the ink conduit is arranged, the projecting parts of the round disc being constituted by rolls that are rotatably supported between the flanges.

16. Printing machine according to any preceding claim, wherein the amount of ink periodically dispensed is variable.

17. Printing machine according to any of claims 8 to 16, wherein an adjusting member acting as a stop forthe coupling plate is screwed in a wall of the housing.

18. Printing machine substantially as described with reference to and as shown in any Figure of the drawings.

19. Metering device for a printing machine according to any preceding claim, which is actuable bythe motion of the printing means so as to periodically supply a metered amount of ink.

20. Metering device for a printing machine substantially as described with reference to and as shown in any Figure of the drawings.