The present invention relates to a device for directly feeding ink prepackaged in containers to the ink duct of printing machines. Printing machines are provided with ink ducts containing the ink to be accurately dispensed to the rollers and rotary cylinders which by their combined action ink the printing matrix. During their operation the ink ducts have to be constantly filled with ink to prevent the printing being compromised or impeded by deficiency or lack of ink.
Progressing from manual filling of the ink ducts, done by manually withdrawing the ink from cans by means of a spatula, the most advanced methodologies involve automatic feeding directly from large-dimension containers or drums (vessels). The drums are positioned outside the printing machine and feed the ink to the ink duct via a complex system comprising pumps, valves and pipes. As a printing machine is provided with several ink ducts and can at any given time use inks of various colours, an ink feed pipe must reach each ink duct from all the drums (vessels). Such complex systems can evidently be used only in printing machines of large format and/or high print run, which consume ink in significant quantities and preferably in a limited variety of colours, for example four colours.
A minimum consumption of many inks not only does not justify the large-quantity purchase of these inks, but also prejudices the operability of the feed systems, which are unable to provide all the inks usable for printing unless the drums (vessels) in use are replaced after previous cleaning of the connection pipes to the ink ducts. Adding to this the fact that such systems, even though provided with ink level control in the ink duct, feed the ink in large quantity and with evident wastage at the end of the print run as the ink, which tends to oxidize, cannot be left a long time in the ink duct and, in any event, if the subsequent work requires another ink, the residual quantity of the ink in use must necessarily be removed.
A second category regards those feed systems using a cartridge containing a small or modest ink quantity, the ink being expelled from the cartridge by pressing the cartridge. Although these systems offer greater constructional simplicity and flexibility of use (such that they can also be applied on machines of medium-small format and/or low print run) they present the drawback of requiring a specific type of cartridge which once empty has to be replaced, and a specific construction of the means which exert the pressing action on the cartridge.
An object of the present invention is to provide means and devices which combine the simplicity and flexibility of cartridge feed with the reliability and independence of automatic systems for feeding from a drum (vessel). Another object of the invention is to provide means which enable the ink to be distributed along the length of the ink duct.
A further object of the present invention is to provide means which enable an ink container to be automatically loaded/discharged.
These and further objects and advantages are attained by the device of the invention, the characteristics of which are highlighted in the accompanying claims.
The invention will be more apparent from the detailed description of preferred embodiments thereof given hereinafter by way of non-limiting example and illustrated in the accompanying drawings, in which:
a is a horizontal section through a detail relative to the means for rotating the unit of
b shows schematically the means for vertically sliding the head and base and the means for rotating said base of the unit of
c is a schematic view from above showing the means for rotating the head of the device of
d is a schematic longitudinal section through the ink expulsion means;
a, b, c show schematically three different phases relative to the loading and discharge of the containers by the device of the invention in the variant 3A;
a, b, c show schematically three different phases relative to the loading and discharge of the containers by the device of the invention in the variant 3B;
a, 6b and 6b1, 6c and 6c1 show schematically three different phases relative to the loading and discharge of the containers by the device of the invention in the variant 3C,
a, b, c show schematically three different phases relative to the loading and discharge of the containers by the device of the invention in the variant 3D.
With reference to the figures, a first version of the device of the invention comprises an ink container-holding and ink dispensing unit indicated by 1″ comprising a head 2, two mutually cooperating jaw elements 3a and 3b, a base 4 and a support part 5.
In the illustrated example the support part comprises two upper parallel columns 6a, 6b and two lower parallel columns 6c, 6d connected respectively to the part 2a of the head 2 and to the part 4a of the base 4 (described hereinafter), and an intermediate connection element 7 having an approximately T-shaped cross-section extending partly between the two jaw elements 3a, 3b.
The intermediate element 7 (see
On the pin 8, between the bearings 10, there is keyed a gearwheel 11 engaging a rack 12 which is axially guided within said support member 9 and driven by a pneumatic actuator 13 fixed thereto. Consequently the support part 5 can rotate about the geometrical axis G of the pin 8 (arrows F1).
The head 23 comprises two parts 2a, 2b. The part 2a is rigid with the two upper columns 6a, 6b, which are mounted slidable via conventional bearings or slide supports, not shown, on the intermediate connection element 7, and is driven by two cooperating coaxial pneumatic actuators, partly shown, provided with rods 15a, 15b, the first 15a of which is connected to the part 2a, while the second 15b is connected to the connection element 7 by a connection plate 15c.
The part 2a presents at one of its ends a jutting connection plate 16 fixed in proximity to a lateral edge of the part 2a and to which is fixed the pin 17 passing in an eccentric position through the part 2b which is rotatably supported on said pin 17 via thrust bearings 18. On the side distant from the pin 17 the part 2b presents means for rotating it (about the pin 17) such as to bring it into the position shown by dashed lines in
In the part 2b a cylindrical chamber 21 is present within which an expulsion means 22 sealedly slides to expel the ink from a container 23 which contains it. In
The base 4 comprises two parts 4a, 4b hinged together at 30.
The part 4a of the base is rigid with the lower columns 6c, 6d, which are mounted slidable within the intermediate connection 7, and is driven by a drive arrangement partly shown (in
The part 4b is rotated (arrows 4) about the axis or pin of the hinge 30 for example by the device shown in
The jaw elements 3a, 3b are supported rotatable (arrows F5), but axially immovable, by the upper columns 6a, 6b and by the lower columns 6c, 6d. In the position shown in
In proximity to their upper and lower ends the two jaw elements 3a, 3b present grooves 37a, 37b shaped such as to mate, when applied thereto, annular projections 38, 39 on the part 2b of the head 2 and on the part 4b of the base 4 respectively, to achieve a reliable closure.
Controlled rotation of the jaw elements (arrows F5) is obtainable, for example, by the device shown in
With specific reference to
Specifically, the conduit 43a feeds compressed air into the cylindrical chamber 21 to move the telescopic piston 22 (in the sense of expelling the ink), while the conduit 43b, formed both in the part 2b of the head 2 and in the wall of the upper component 24 of the telescopic piston 22, feeds compressed air into the cylindrical chambers 44a, 44b to move it in the opposite direction.
The versions of these figures differ in that they dispense ink from three different types of container. In these figures, identical or corresponding parts of the device (but not of the container) are indicated by the same reference numerals as previously plus 100, 200 and 300 respectively, whereas different parts do not follow this rule.
In these figures the jaw elements 103a, 103b; 203a, 203b; 303a, 303b are closed to define the compartment 36 for holding the ink container. The container of
Instead of the expulsion means 22 of
The part 102b of the head 102 comprises a sensor 51 which enters the cylindrical chamber 121, to monitor the extension of the expulsion means and hence indicate the level of ink in the container and warn, with adequate warning, of the empty state to enable the container to be immediately replaced either by the operator, or automatically (as described hereinafter).
A further sensor 52 projects from the part 104b of the base 104 to sense the ink level in the underlying conventional ink duct C of the printing machine, from which the ink is withdrawn by a conventional doctor roller R.
In detail, the cartridge 123 is provided at its dispensing nozzle 127 with a unidirectional valve U having flexible or spring-loaded internal components which, under the thrust exerted by the ink subjected to the action of the telescopic piston, opens to enable the ink to be dispensed. A valve of this type is shown in
The pressing disc in question acts directly on the ink contained in the pot after a usual lid, not shown, has been removed therefrom.
Closure takes place when the sensor 52 senses a sufficient degree of filling of the underlying ink duct C.
The container-holding and ink dispensing unit operates in various ways based on the mobility of its various components.
With the jaw elements (3a, 3b; 103a, 103b; 203a, 203b; 303a, 303b) widened apart, and with the head (2; 102; 202; 302) and/or a head part (2b; 102b; 202b; 302b), the base (4; 104; 204; 304) and/or a base part (4b; 104b; 204b; 304b) raised or rotated outwards, the operator can remove an empty ink container and replace it with another full container. The base and/or base part, the head and/or head part and the jaw elements are then moved in the reverse order to retain the container and enable the expulsion means of the head to exert on the container the pressure necessary to dispense the ink.
Specifically, the jaw elements (3a, 3b; 103a, 103b; 203a, 203b; 303a, 303b) are firstly made to widen (arrow F5 in
A full container is loaded in the same manner but in the reverse order: the head and/or head part and the base and/or base part are partially withdrawn from each other and then, after opening the jaw elements, are applied completely to the container. The final rotation of the jaw elements to close them re-inserts the annular projections on the head and base part into the corresponding grooves in the jaw elements.
A further method of removing the container is to rotate the entire unit 1″ through a given angle about the horizontal axis (G in
To load a full container with the device inclined, the container is positioned manually on one of the jaw elements which, by interacting with the part (4b; 104b; 204b; 304b) of the base (4; 104; 204; 304), are moved in the reverse order as far as their initial position so that the entire device can be rotated into a vertical position.
Other methods will be apparent hereinafter.
The unit 1″ can be mounted stationary, i.e. in a fixed position, by the connection flange 9a (
The device of the invention also comprises the version in which its unit 1″ is supported such that it can move linearly above the ink duct C, as shown schematically in
Movement in the two directions along the rectilinear guide 69 is obtained for example by a conventional rod-less pneumatic cylinder 72 as shown, or by a recirculating ball or toothed belt transmission.
In operation, the unit 1″ is made to translate from right to left and vice versa along the rectilinear guide 69, i.e. with intermittent reciprocating movement, above the ink duct C then, when its ink level control sensor 52 senses a lack of ink in a region of the ink duct C, it feeds a signal to an electronic control unit which controls the action of the expulsion means 22 (for example the telescopic piston with three components 46, 47, 48) to dispense the ink from the container into that given region of the ink duct. In this manner, the ink is well distributed and fed differentially into the various regions of the ink duct on the basis of the consumption in each of them.
The unit 1″ can be advantageously implemented as a component of the device of the invention in the form of variants able to automatically change the ink container, as shown schematically in
Specifically, in
The part 4b of the base 4 is rotated by opening and closing the jaw elements 3a, 3b to a given extent and for a given number of times, for their engagement and disengagement (in the already described manner). In the version of
The front wall 504 lowerly presents for the empty containers a discharge aperture 509 bounded lowerly by an inclined plane 510 by which the empty container is conducted to an underlying lateral collector vessel 511. The device which governs the fall of one container at a time from the vertical channel 501 comprises two pairs of profiled levers 512, 513 (only one pair is visible in
When an empty container (this fact being sensed by the sensor 51 of
The jaw 3b rotates into its closed position to close the fallen container between it and the other jaw 3a; the base 4, simultaneously with the head 2, partly approaches and then, after the jaw elements have been opened, is completely applied to the container; the unit 1″ is made to leave the chamber 503; having left, it is made to assume a vertical position and can then translate along the ink duct C to dispense ink.
In the version of
The outer wall 606 of the circular channel 601 presents an aperture 607 which enables the unit 1″ to be inserted into the store for loading and removing the containers.
In this respect, the store can be driven linearly along a geometrical axis perpendicular to the support structure for the unit 1″ (arrow Z) by an actuator and rectilinear guides (not shown).
When the sensor 51 (
The variant of
The fill containers 702 are removably supported spaced apart on an endless conveyor 703 advancing in the direction of the arrow Z. The containers are removably retained between two half-jaw elements 704, 705 rigid with the conveyor 703 and projecting laterally from them. One of the half-jaw elements presents a lateral fin or extension 706 arranged to interfere with a stationary member 707 so as to flex, in the opposite direction to the arrow Z, to release the container which can then fall into the underlying unit 1″ which, as can be seen from
The aforegoing refers to the loading of a full container into the unit 1″, however this must be preceded by removing the empty container from the unit 1″. Removal takes place when the unit lies in the extension, in the position for loading a full container. In this position the unit 1″ lies above a discharge conduit 708 (
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MI2002A2364 | Nov 2002 | IT | national |
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