'A FLEXO-PRINTING UNIT WITH MECHANISM FOR SYNCHRONOUSLY MOVING SIDE BRACKET ASSSEMBLIES AND METHOD THEREOF'

Abstract

Abstract 'A FLEXO PRINTING UNIT WITH MECHANISM FOR SYNCHRONOUSLY MOVING SIDE BRACKET ASSSEMBLIES AND METHOD THEREOF' The present invention relates to flexo printing unit with mechanism for synchronously moving side bracket assemblies and its method. More particularly, it relates to printing on both sides of paper, applicable to 2-4-6-8 color stack type flexo printing units. The unit comprises a Left Hand (2) side and Right Hand (3) side bracket assemblies, between which an anilox roll and rubber roll are supported in parallel, both bracket assemblies are configured to move synchronously. An adjustment shaft (4) connects both assemblies and operated via crank handle, allowing for precise control. The invention employs bevel gear system that translates rotational motion from adjustment shaft (4) to threaded shafts, enabling synchronized movement of bracket assemblies. This mechanism simplifies the graphic roll changeover process, allowing a single operator to efficiently manage the task, thereby significantly reducing maintenance time compared to conventional methods. The user-friendly design enhances operational convenience, making it effective and efficient. Fig.5

Specification

Description:


FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION: 'A FLEXO-PRINTING UNIT WITH MECHANISM FOR SYNCHRONOUSLY MOVING SIDE BRACKET ASSSEMBLIES AND METHOD THEREOF'
2. APPLICANT:

(a) NAME : Patel Udaykumar Chhabildas
(b) NATIONALITY : Indian
(c) ADDRESS : 38/A, Nirant Park House,
Opp. Sun-N-Step Club,
Thaltej, Ahmedabad - 380061
Gujarat, India.
3. PREMABLE TO THE DESCRIPTION:
PROVISIONAL
The following specification
describes the invention.  COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

The following specification particularly describes the invention and the manner in which it is to be performed.



Field of the Invention
The present invention relates to the field of flexographic printing technology. More specifically, it pertains to a flexo printing unit equipped with a mechanism for synchronously moving side bracket assemblies.

Background of the Invention
The typical flexographic printing station is stack type - in 2 color / 4 color / 6 color / 8 color printing stations. 2 color / 4 color / 6 color / 8 color printing stations consist of 2 nos. / 4 nos. / 6 nos. / 8 nos. of impression roll respectively. Ink delivers to rubber roll through pump from ink reservoir, rubber roll to anilox steel roller, anilox steel roller to plate cylinder, plate cylinder to impression roller. Substrate passes between plate cylinder & impression cylinder.

Flexography is unique among other printing processes in that it was developed primarily for the printing of packaging materials as well as exercise notebook. Since packaging materials are mostly used in roll form for feeding into form and fill, overwrapping, bag making and other continuous web processing machines, it follows that most flexographic printing is done roll to roll. Flexography has grown today beyond the printing of packaging materials and now includes a wide variety of other products.

In its simplest and most common form, the flexographic printing system consists of four basic parts: rubber roll, anilox roll, plate cylinder, and impression cylinder.

The rubber roll is generally a rubber-covered roll of either natural or synthetic rubber or EPDM rubber. It is positioned to rotate in a reservoir of thin ink. Its main purpose is to pick up and deliver ink from the reservoir to the anilox roll. The anilox roll is usually a metal roll either chrome plated or ceramic coated roll engraved over its entire surface with tiny cells numbering from 80 to over 1200per lineal inch. The purpose of the anilox roll is to supply a controlled, metered, fine film of ink to the printing plates affixed to the plate cylinder. For this reason, the rubber and anilox rolls are set to rotate under considerable pressure against each other in a wringer-like action to squeeze away excess ink from the surface of the anilox roll, leaving ink primarily in the engraved cells. The anilox roll in turn continues to rotate and ink is deposited on the raised image area of the printing plate on the plate cylinder.

The contact pressure of the anilox roll to the printing plate is set to be as light as practical in order not to over ink or cause ink to be pressed down on the shoulders of the raised image area of the plates. Flexo graphic printing system all rollers drive through gear trains. Drive transfer through gear from impression cylinder to plate cylinder, plate cylinder to anilox roller and anilox roller to rubber roller. Plate Cylinder changed in flexo graphic system with respect to change in print length on substrate. Variations of the common flexographic two-roll inking system described above are possible.

In Other variations - rubber roll eliminates in flexo graphic system. Doctor blade chamber system positioned instead of rubber roll, ink deliver to doctor blade chamber system from ink reservoir with use of diaphragm pump. Doctor blade chamber system - double side knife in pressure with anilox roll to main precise lever of ink of anilox roll.

The anilox roll transfers a finely metered film of ink to the raised surface of the plate, which in turn transfers the ink to the surface of the substrate or web. The impression roll is a smooth polished metal cylinder which serves to back up and support the substrate as it comes in contact with the printing plate. The surface speed of the impression cylinder with substrate must be identical to that of the plate cylinder and anilox roll. Otherwise, slurring, halos, smeared printing and reduced plate life will result. In this flexo graphic system - access ink in doctor blade system return to reservoir either gravity return or through pump.

One another flexo graphic system is that in which plate cylinder eliminate by air graphic mandrel - in which outer surface of sleeve carries printing matter& sleeve fixed on air graphic mandrel.

The roll of stock to be printed must be held under control so that the web can unwind into the press as needed, in proper alignment and under proper tension to prevent slack and wrinkles. The tension should be not so great that it will cause web stretching or breakage. In simplest form, this all may be accomplished by holding the roll in chucks on a steel shaft mounted in plain bearings with a manually controlled hand brake for tension control and a threaded rod and hand wheel for lateral adjustment. In prior art systems, almost continuous monitoring of the system by the operator is required.

In the prior art, US6142073 A, cited document relates to the plate roll and anilox roll of certain designs of flexographic presses comprise a mandrel and a sleeve which is removably mounted on the mandrel. The outer surface of the sleeve of the plate roll carries the print image. The outer surface of the sleeve of the anilox roll is coated with ceramic and is engraved for controlled pick up of ink and transfer of ink to the plate roll. In some flexographic presses, both ends of the plate and anilox rolls are supported in bearings on the front and back frames of the press. In order to exchange a roll or the sleeve of a roll, the front bearing or bearing housing is removed from the front end of the roll, and the back end of the roll is supported as a cantilever in the back bearing. However, the front end of the roll is inside of the front frame, and the operator must reach into the frame to remove the roll or to remove the sleeve of a roll. Two problems are thereby presented--potential operator injury and potential damage to the outer surface of the roll.

In conventional method of Printing the anilox roll, rubber roll and flexo graphic roll are holding on to the bracket assemblies and when print length is changed, there occurs a need to replace flexo graphic roll as per print length, in that case there is a need to move the brackets in reverse direction, where both side brackets are mounted on threaded rod with knobs. These knobs are required to rotate so that side brackets move away from the flexo graphic roll. However, in such a conventional approach, both knobs are required to rotate in synchronizing manner. Therefore, two operators are required to rotate both side knobs for forward-reverse motion in synchronized manner. Further, in such a process, major time is taken, more accuracy is required and sometimes jam problems are observed due to non-synchronous operation of the knobs.

Therefore, there is an unmet need to solve the above said problem of conventional method, the present invention which overcomes all above issues and maintains the functionality of the mechanism.

Object of the Invention
The main object of the present invention is to provide a flexo printing unit with a mechanism for synchronously moving side bracket assemblies and its method.

Yet another object of the present invention is to provide a flexo printing unit with a mechanism for synchronously moving side bracket assemblies handed by a single operator for the graphic roll changeover in the printing unit.

Yet another object of the present invention is to provide a flexo printing unit with a mechanism for synchronously moving side bracket assemblies easier and quicker compared to conventional methods.

A further object of the present invention is to provide a flexo printing unit with a mechanism for synchronously moving side bracket assemblies, making it more efficient, user friendly, affordable, and easy to handle while reduced change over time compared to conventional design.

Another object of the present invention is to provide a flexo printing unit with a mechanism for synchronously moving side bracket assemblies to avoid assembly jam problems.

A further object of the present invention is to provide a flexo printing unit that features a mechanism for synchronously moving side bracket assemblies, thereby improving the precision and efficiency of the printing process.

Another object of the invention is to provide a flexo printing unit that features a mechanism which enhances printing accuracy by allowing simultaneous adjustments of the side brackets, which minimizes misalignment during operation.

A further object of the invention is to provide a flexo printing unit that features a mechanism to reduce downtime and simplify the setup process for operators, thereby increasing productivity in flexographic printing applications.


Summary of the Invention
The present invention relates to a flexo printing unit to incorporate a mechanism for synchronously moving side bracket assemblies. This innovative mechanism allows for simultaneous adjustments of the side brackets, significantly enhancing the precision of printing and operational efficiency. More particularly, it relates to a flexographic printing unit designed to facilitate the printing of paper on both the front and back sides, applicable to 2-4-6-8 color stack type flexo printing units. The flexographic printing unit further comprises a Left Hand (LH) side bracket assembly and a Right Hand (RH) side bracket assembly, with an anilox roll and rubber roll supported in parallel between them. A flexographic roll assembly, positioned downstream, receives the paper web after it passes through the anilox and rubber rolls. To enhance the efficiency of flexo graphic roll changeovers, the invention features a mechanism that allows for the synchronized forward and reverse movement of the LH and RH side bracket assemblies. Each bracket assembly includes an adjustment bracket, an anilox and rubber roll mounting bracket, and a main bracket. The adjustment brackets are equipped with threaded shafts that slide within corresponding threaded rods, enabling controlled movement. An adjustment shaft extends between the two bracket assemblies, allowing rotation via a crank handle. This rotation engages a system of bevel gears that transmits motion from the adjustment shaft to the threaded shafts, causing the bracket assemblies to move outward simultaneously. This synchronized movement allows for easy removal and replacement of the flexographic roll. The present invention provides significant advantages, including simplified maintenance, faster graphic roll changeovers, and a user-friendly design that can be operated by a single individual. The mechanism enhances the operational efficiency of flexographic printing units, making it a valuable advancement in the field of printing technology.

Brief Description of the Drawings
The present invention is readily understood with reference to the following specifications and attached drawings wherein:

Figure 1 shows an overview of printing tower unit according to the present invention.

Figure 2 shows perspective view of left-hand and right-hand side bracket assembly according to present invention.

Figure 3 shows detailed view side bracket assemblies according to present invention.

Figure 4 shows across sectional view of side bracket assemblies according to the present invention.

Figure 5 shows a mechanism for synchronously sliding bracket assemblies according to the present invention.

Detailed Description of the Invention
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the mechanism and arrangement of parts illustrated in the accompanying drawings. The invention is capable of other embodiments, as depicted in different figures as described above and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.

The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show mechanical details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.

It is to be also understood that the term "comprises" and grammatical equivalents thereof are used herein to mean that other components, ingredients, steps, etc. are optionally present. For example, an article "comprising" (or "which comprises") components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also contain one or more other components.

FIG. 1 illustrates a flexographic printing tower unit (1)to print the paper on front & back side. The present invention is applied to all 2-4-6-8 color stack type flexo printing unit.

Referring to Fig. 2, the flexographic printing tower unit according to a present invention comprises a Left-hand side bracket assembly (2) and a Right-hand side bracket assembly (3). Between said Left hand side bracket assembly (2) and a Right-hand side bracket assembly (3), an anilox roll and rubber rolls are parallelly supported. A flexo graphic roll assembly (not shown) is mounted downstream to the rubber roll to receive paper web passing through the anilox roll and rubber roll. Now in order to remove the flexo graphic roll from the printing unit, the Left hand side bracket assembly (2) and a Right Hand side bracket assembly (3) are moved forward and reverse in the manner as described below.

Referring to Fig. 3 and 4, each said bracket assemblies (2, 3) comprises a fix bracket (5) mounting with main body (7) & adjustment bracket (18), an anilox and rubber roll mounting bracket (6) being fitted on top of the adjustment bracket (18). Fix bracket (5) is fixed with main body (7). Said adjustment bracket (18) is provided with threaded shafts (8) and (9) which are configured to slide the bracket assembly forward and reverse in the manner as described below. Further, said threaded shaft (8) and (9) are slidable inside threaded rod (10) and (11) respectively that having an inner threaded surface to match with the outer threaded surface of respective threaded shafts (8) and (9).

Now as shown in Fig. 2, an adjustment shaft (4) is extended between LH side bracket assembly (2) and Right-hand side bracket assembly (3). Both ends of said adjustment shaft (4) is rotatably received within a U shaped groove of the main body (7) of both side bracket assemblies. At one of ends of the adjustment shaft (4), a crank handle is mounted for enabling rotation of the adjustment shaft (4) in clockwise and anticlockwise direction.

Referring to Fig. 3 and 5, an inner bracket (12) is fixed with the adjustment bracket (18) at rear side thereof. The rear ends of the threaded rods (9) and (8) are extended from the inner bracket (12). Now, on the extended portion of the rods (9) and (8), a bevel gear (13) and spur gear (14) is provided respectively. Further, between said bevel gear (13) and spur gear (14), an idler gear (15) is positioned such that the teethes of the idler gear mashes with teethes of bevel gear (13) and spur gear (14) so that the rotational motion of the bevel gear (13) is transferred to the spur gear (14).

Referring to Fig. 5, bevel gears (16) are mounted on the adjustment shaft (4). The rotational axis of said bevel gear (16) is perpendicular to the rotational axis of the bevel gear (13). Further, said bevel gear (16) and bevel gear (13) are positioned such that teethes of the bevel gear (16) perpendicularly meshes with teethes of the bevel gear (13).

Now in operation, when the user needs to remove the flexo printing roll, the adjustment shaft (4) is rotated in anticlockwise direction with the help of crank handle. Along with rotation the adjustment shaft (4), the bevel gears (16) mounted on the adjustment shaft (4) transfer the rotational motion to the bevel gear (13) of both assemblies (2, 3) & the bevel gear (13) transfers the rotational motion to the spur gear (14) through the idler gear (17). Along with rotation of bevel gear (13) and gear (14), the threaded shafts (9) and (8) slides in outward direction within the threaded rod (11) and (10) respectively so that the bracket assemblies move away from the flexo graphic roll in synchronizing manner. After that, the operator opens the flexo roll top bracket and places a new flexo roll and fit the top bracket again. Then after, the crank shaft handle is rotated in clockwise direction so that bracket assembly moves in reverse direction.

Beneficial effects of the present invention are, both (3) and (2) side bracket assembly are moved forward and reverse in synchronizing manner so that single operator can handle the graphic roll changeover in the printing unit, the maintenance of the printing unit with such mechanism is very easy and convenient, graphic roll changeover of the printing machine is very fast compared to the other conventional methods, the said mechanism and design of the printing unit is user friendly and said assembly can also be handled conveniently.

The invention has been explained in relation to a specific embodiment. It is inferred that the foregoing description is only illustrative of the present invention, and it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure. All substitution, alterations and modification of the present invention which come within the scope of the following claims are to which the present invention is readily susceptible without departing from the spirit of the invention. The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled.


List of Reference Numerals:
1. Printing Tower Unit
2. Left hand side bracket assembly
3. Right Hand side bracket assembly
4. Adjustment shaft
5. fixed bracket
6. Anilox and rubber roll mounting bracket
7. Main body
8. Threaded shaft
9. Threaded shaft
10. Threaded rod
11. Threaded rod
12. Inner bracket
13. Bevel Gear
14. Main gear
15. Idler gear
16. Bevel gear
17. Idler gear
18. Adjustment bracket



, Claims:We claim:

1. A flexo printing unit (1) with mechanism for synchronously moving side bracket assemblies comprising a Left Hand side bracket assembly (2); a Right Hand side bracket assembly (3) located spaced apart from the left hand (2) side bracket assembly an anilox roll and a rubber roll supported in parallel between said side bracket assemblies (2, 3); and a flexographic roll assembly mounted downstream to the rubber roll for receiving a paper web passing through the anilox roll and rubber roll;
each said bracket assembly (2, 3) comprises an adjustment bracket (18); an anilox and rubber roll mounting bracket (6) fitted on top of the adjustment bracket (18); said adjustment bracket (18) is fixed with main body (7);
Characterized by said adjustment bracket (18) includes threaded shafts (8) and (9) configured to slide the bracket assemblies forward and reverse, said threaded shafts (8) and (9) being slidable within corresponding threaded rods (10) and (11) having an inner threaded surface; an inner bracket (12) is fixed with adjustment bracket (5) at rear side thereof.
Said threaded shaft (8) and (9) are mounted with spur gears (14) and bevel gear (13) respectively at rear end thereof and an idler gear (17) is located between said gears (13) and (14);
an adjustment shaft (4) extended between side bracket assembly (2, 3); said adjustment shaft (4) is provided with bevel gears (16);
said bevel gear (13) is configured to mesh with the bevel gear (16) mounted on the adjustment shaft (4).

2. The flexographic printing unit (1) as claimed in claim 1, wherein both ends of said adjustment shaft (4) are rotatably received within a U-shaped groove of the main bracket (7).

3. The flexographic printing unit (1) as claimed in claim 1, wherein a crank handle is mounted on one end of the adjustment shaft (4) for enabling rotation in both clockwise and anticlockwise directions.

4. The flexographic printing unit (1) as claimed in claim 1, wherein the rotational axes of said bevel gear (16) and the adjustment shaft (4) are positioned perpendicularly to one another, allowing for efficient transfer of motion.

5. The flexographic printing unit (1) as claimed in claim 1, wherein said bevel gear (16) and bevel gear (13) are positioned such that teethes of the bevel gear (16) perpendicularly meshes with teethes of the bevel gear (13).

6. The flexographic printing unit (1) as claimed in claim 1, wherein between said bevel gear (13) and gear (14), an idler gear (15) is positioned such that the teethes of the idler gear mashes with teethes of bevel gear (13) and gear (14) so that the rotational motion of the bevel gear (13) is transferred to the gear (14).

7. A method for synchronously moving side bracket assemblies, comprising the steps of:
a. rotating the crank handle to turn the adjustment shaft (4) in an anticlockwise direction.
b. transferring rotational motion of the bevel gear (16) to the bevel gear (13) and gear (14) through idler gear (17).
c. sliding the threaded shafts (9) and (8) inside the threaded rod (11) and (10) respectively to enable the bracket assemblies (2, 3) move forward.
d. removing the top bracket of the flexo roll to access and replace the flexographic roll.
e. rotating the crank handle in a clockwise direction to move the bracket assemblies back to their original position.

8. The method for synchronously moving side bracket assemblies as claimed in claim 6, wherein a single operator can perform the graphic roll changeover quickly and efficiently due to the synchronized movement of the (2) and (3) bracket assemblies.
Dated this on 7th day of November, 2024

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