Winding machine for printed substrates and related control method

Abstract

In order to solve the problem of prolonged machine downtimes and the customisation of the spring-loaded trolley (3) displacement device according to the material being processed, a winding machine with a trolley displacement device was realised so as to have: • - a motor (M3) configured to position the trolley in an adjustable starting position relative to the frame and to move the sliding trolley in both directions along the forward direction; • - a microprocessor unit to control the motor, configured to receive user commands representing the adjustable starting position and a travel speed of the trolley, wherein the microprocessor unit can also be programmed to adjust the travel speed and the position of the trolley as the reel is formed. A corresponding control method is also disclosed.

Description

[0001] WINDING MACHINE FOR PRINTED SUBSTRATES AND RELATED CONTROL METHOD

[0002] TECHNICAL FIELD

[0003] This disclosure relates to machines for winding sheets of paper, and more particularly to a winding machine for winding printed substrates, such as large-format sheets of paper, onto themselves without a rigid base roll, as well as a related control method.

[0004] BACKGROUND

[0005] Machines are known in the industry for winding large sheets of paper, such as posters. A known winding machine is illustrated in figure 1 and includes: a sliding trolley 3 that slides with respect to the machine frame; two pairs of equi -rotating rollers 1, 1', 2, 2', wherein rollers 1, T have their respective axes of rotation fixed to the frame and rollers 2, 2' have their respective axes of rotation fixed to the sliding trolley 3 so as to be able to translate with respect to the first pair of equirotating rollers 1, 1'; a motor assembly Ml-1', M2-2', functionally connected to rollers 1, 1', 2, 2' to turn them all in the same direction; a displacement device, functionally connected to move the trolley 3.

[0006] The equi-rotating rollers 1, 1', 2, 2' are configured to receive a front flap of a printed substrate S, to advance it in a forward direction and to drag it into a defined roll-up gap between the equi-rotating rollers 1, 1', 2, 2' and to wind the substrate S onto itself in the roll-up gap.

[0007] The printed substrate S, arriving from an in-line cutter or a table, is introduced into the roll-up gap defined by two pairs of equi-rotating rollers, e.g. defined by axes with interpenetrating rollers 1, 1' and 2, 2'. Axes 1, 1' are fixed to the frame while axes 2, 2', integral with trolley 3, translate as the roll increases in diameter, as illustrated in figure 2. These axes are driven by the motor assembly Ml-1', M2-2', which determines the rolling speed of the substrate S.

[0008] The trolley 3 translates along the ground guide 8 by means of the bearings 7, 7', 7", 7”’ arranged in such a way as to prevent the trolley 3 from tilting, which translates in a guided manner thanks to the pinions 4, 4' which engage on the racks 6, 6'. The pinions 4, 4' are connected to the same torsion shaft 5 integral with the trolley 3. The torsion shaft 5 thus enables the trolley 3 to move in such a way that the equirotating rollers 2, 2', which can be realised by means of roller axles, always move parallel to the axles of the rollers 1, 1'. The trolley 3 is attached to a manually adjustable spring system. The spring 9 has a direct engagement on the trolley 3, while on the other side of its length it is bound to the machine frame by a threaded rod 10, which is adjustable on a bracket by means of ring nuts 11, 11'. The action of the ring nuts 11, I T on the threaded rod 10 allows a greater or lesser initial pre-tensioning of the spring 9 depending on the type of printed substrate S or on the diameter of the reel to be wound. Therefore, the initial spring tension influences the winding characteristics performed by the winding machine.

[0009] When the reel is fully formed within the roll-up gap between the roller axles, sensors installed on the machine send signals to a solenoid valve which actuates the pneumatic cylinder 12. As illustrated in Figure 3, the pneumatic cylinder 12 pushes the trolley 3 by overcoming the return force of the spring 9 to open the roll-up gap and drop the printed substrate reel S rolled up into a collection area at the bottom of the machine. Typically, the pneumatic cylinder 12 is energized until the printed substrate reel S reaches a sensor (not shown) in the reel collection area, after which the pneumatic cylinder 12 is not energized and the trolley 3 returns to the starting position shown in figure 1 pulled by the spring 9, ready to begin a new coiling cycle.

[0010] The machine in figures 1 to 3 is convenient to use if it is only needed to roll printed substrates of one type or at least based on similar paper weights, which do not require a continuous adjustment of the spring pre-tensioning 9. Customers who need to process multiple types of materials, thicknesses and weights, experience long downtimes due to the complexity of the mechanical adjustment of the spring system, which must be done by experienced personnel in order to achieve the desired results, so that springs must be replaced with others with different elastic characteristics, thus forcing the customer to have to set up the machine according to production requirements.

[0011] SUMMARY

[0012] In order to solve the problem of prolonged machine downtimes and the customisation of the spring-loaded trolley displacement device according to the material being processed, a winding machine as defined in the claims and illustrated in the attached figures was realised. Basically, the known machine displacement device, based on the use of springs 9 and piston 12 to drop the reel when complete, has been redesigned to have:

[0013] - a motor configured to position the trolley in an adjustable starting position relative to the frame and to move the sliding trolley in both directions along the forward direction;

[0014] - a microprocessor unit to control the motor, configured to receive user commands representing the adjustable starting position, configured by the user himself, to adjust the speed of movement of the trolley and its position as the reel is formed.

[0015] The winding machine is controlled through the following parameters and operations: Using the microprocessor unit, positioning the trolley in the adjustable starting position; starting the motor assembly to wind the printed substrate; with the motor moving the trolley and with the microprocessor unit adjusting the position of the trolley according to:

[0016] - a feed rate of the printed substrate towards the roll-up gap,

[0017] - an equi-rotating roller speed,

[0018] - the adjustable starting position,

[0019] - a thickness of the printed substrate,

[0020] - a parameter or curve chosen by the user, which will define a change in reel compression at various instants of the winding process.

[0021] Further embodiments are defined in the attached claims.

[0022] BRIEF DESCRIPTION OF THE DESIGNS

[0023] Figure 1 shows a winding machine with a spring-loaded trolley as it starts to wind a printed substrate.

[0024] Figure 2 shows the machine in Figure 1 rolling up a printed substrate with the trolley spring forced to stretch as the diameter of the reel increases.

[0025] Figure 3 shows the machine in figure 1 with a piston that pulls the spring-loaded trolley away to drop the printed substrate reel completely wound around itself.

[0026] Figure 4 shows a winding machine of the present disclosure with a motorised trolley as it starts to wind a printed substrate.

[0027] Figure 5 shows the machine of figure 1 rolling up a printed substrate with the trolley being moved gradually by a motor controlled by a microprocessor unit.

[0028] Figure 6 shows the machine of figure 1 with the trolley moved by the motor to drop the printed substrate reel completely wound around itself.

[0029] DESCRIPTION OF EXEMPLARY EMBODIMENTS OF REALISATION

[0030] A winding machine according to the present disclosure is illustrated in Figures 4 to 6 in various stages of operation. The same features shown in figures 1 to 3 are shown in figures 4 to 6 with the same numerical references.

[0031] It differs from the known machine illustrated in Figures 1 to 3 in that the displacement device of trolley 3 is not realised by means of a spring system, but is based on an electronically controlled system via a microprocessor unit.

[0032] In detail, an M3 motor is installed on the trolley 3, connected to the torsion shaft 5 via a kinematic mechanism 13. With respect to the known machine of figure 1, the pinion axis 4, 4' is no longer passively rotated by the advance of the trolley 3 as the outer diameter of the printed substrate reel S increases, but is connected to the motor M3 which rotates it and in this way determines the displacement of trolley 3. On the same axis of the pinions 4, 4', now driven by the motor M3, an encoder 13 is installed to control the displacement made by the trolley 3 during its movement.

[0033] It is therefore understood that, unlike in the known machine of figure 1 in which the movement of the trolley 3 is regulated by the thrust of the material on the rollers 2-2' and counteracted by the force of the spring 9, in the machine of the present disclosure such a movement is controlled. Being known, thanks to the management electronics of the machine, the feed speed of the printed substrate S and combining to it the adjustable speed of the trolley 3 and of winding by means of the speed of the equirotating rollers 1, 1', 2, 2', a full control, instant by instant, of the formation characteristics of the reel is obtained. In fact, knowing the speed at which the substrate S enters the roll-up gap, acting on the position of the trolley 3 by means of the control of the motor M3, the correct compensation relative to the variation of the thickness of the material is obtained by directly setting the number of revolutions of the motor M3 by means of the microprocessor unit installed on the machine, instead of having to act on the spring tensioning mechanics 9 as is the case with the known machine in figure 1. The electric motor M3 can be adjusted to deliver a regulated torque over a wide range, so that the machine according to the present disclosure can support both reels of small diameter and low weight material, as well as reels of large diameter and thick material without having to change any element of the machine, but simply by acting on the electronic regulation via the microprocessor unit. It is also possible to control, at every instant of the winding process, the compression of the obtained reel.

[0034] According to one aspect, the winding machine is equipped with a touch screen interface configured to set various combinations of substrate feed speed S, winding speed within the roll-up gap formed by the equi-rotating rollers 1, 1', 2, 2' and trolley movement speed 3. This interface can also be used to memorise various programmed combinations so that they can be recalled if necessary.

[0035] According to one aspect, sensors installed on the machine send signals to the microprocessor unit to indicate when the reel is fully formed within the roll-up gap (figure 5). Unlike the known machine of figure 3 in which the opening of the roll-up gap is carried out by the piston 12, the unloading of the reel (figure 6) is handled directly by the microprocessor unit via the motor M3 which, once it receives the signal that the printed substrate reel S is complete, will perform a sudden forward movement sufficient to drop the formed reel onto the reel collection area.

[0036] The sensor located in the reel collection area will confirm to the microprocessor unit that the reel has been unloaded and the M3 motor will be energized to perform the return stroke until the 1-1' and 2-2' roll-up gap is closed and a new cycle begins.

[0037] Due to the fact that the initial position of the trolley 3 and the speed at which the trolley 3 is moved by the motor can be adjusted at will by means of the microprocessor unit controlling the motor M3, the properties of the rolled-up substrate S can be determined. For example, the initial position of the trolley 3 can be adjusted so that the printed substrate S is rolled up on the first turn with a relatively small diameter: this makes it easier to roll up certain printed substrates S that are difficult to roll up if the first revolution of the reel is relatively large. After the first turn, while continuing to roll the substrate S, the trolley 3 is moved with a speed greater than the speed with which the outer diameter of the reel should increase. As a result, the first turn of printed substrate S being rolled tends elastically to expand, increasing the inner diameter of the reel itself. Once the desired inner diameter of the reel has been reached, the speed of movement of the trolley 3 is determined so that it corresponds to the speed with which the outer diameter of the rolled-up substrate S increases. The final result will be an easily formed and perfectly wound reel with a relatively large inner diameter, so that the printed substrate S at the beginning of the reel is not too deformed.

[0038] If, on the other hand, printed cardboard is to be rolled, then in this case it may be convenient to establish a starting position for trolley 3 such that a relatively large rolling space is defined in order to have a large internal diameter of the reel and avoid folding the cardboard too much.

[0039] In general, the travel speed and position of trolley 3 may be determined as a function of:

[0040] - the feed rate of the printed substrate S towards the roll-up gap,

[0041] - the rotation speed of the equi-rotating rollers 1, 1', 2, 2',

[0042] - the adjustable starting position of the trolley 3,

[0043] - the thickness of the printed substrate S or its other physical characteristics, such as flexibility;

[0044] - a variable parameter or 'compression curve' defining a change in the compression provided by the trolley on the substrate reel at each instant of its winding.

[0045] According to one aspect, the microprocessor unit can store the various rolling programmes as defined by the user, who can reuse them each time he needs to roll up a previously rolled S-printed substrate, without the need to change the mechanical configuration of the machine.

[0046] Any variations or additions may be made by the experts in the technical field to the embodiments described and illustrated herein, while remaining within the scope of the following claims. In particular, further embodiments may comprise the technical features of any of the following claims with the addition of one or more technical features described in the text or illustrated in the figures, taken individually or in any combination thereof.

Claims

CLAIMS1. A winding machine for printed substrates, comprising: a frame, a trolley (3) sliding with respect to said frame along an advance direction; a first pair of equi-rotating rollers (1, 1') and a second pair of equi-rotating rollers (2, 2') configured to receive a front edge of a printed substrate (S), to make it advance in said advance direction, to draw the printed substrate (S) into a defined roll-up gap between the equi-rotating rollers (1, V, 2, 2’) and to wind the printed substrate (S) onto itself in the roll-up gap to form a reel, wherein the equi-rotating rollers of said first pair (1, 1') have respective rotation axes fixed to said frame and the equi-rotating rollers of said second pair (2, 2') have respective rotation axes fixed to said sliding trolley (3) so as to be able to displace along said advance direction with respect to the first pair of equi-rotating rollers (1, 1'); a motor assembly (Ml-T, M2-2’), functionally connected to said rollers (1, 1', 2, 2') to make them all rotate in the same direction; a moving device, functionally connected to said trolley (3) and to said frame to move said trolley (3) along said advance direction; characterized in that said moving device comprises: a motor (M3) configured to position said trolley (3) in an adjustable starting position with respect to said frame and to move the sliding trolley (3) in both directions along said advance direction; a microprocessor unit for controlling said motor (M3), configured to receive user commands representative of said adjustable starting position and of a travel speed of the trolley (3), wherein said microprocessor unit is furthermore programmable to adjust the speed movement of the trolley (3) and a position thereof while the reel is being wound.

2. The machine according to claim 1, further comprising an encoder connected to a shaft of said motor (M3) and functionally configured to supply said microprocessor unit with information about movement imparted to said trolley (3) by the motor (M3).

3. The machine according to claim 1 or 2, further comprising a guide (8) fixed to said frame, configured so that the trolley (3) can slide along the guide (8) by means of bearings so as to vary’ a separation distance between the first pair of equi-rotating rollers ( 1 , T) andthe second pair of equi-rotating rollers (2, 2').

4. The machine according to one of the preceding claims, wherein said equi-rotating rollers (1, F, 2, 2') are made by intermeshing wheel axles.

5. A control method of a winding machine for printed substrates, comprising a frame, a trolley (3) sliding with respect to said frame along an advance direction, a first pair of equi-rotating rollers (1, F) and a second pair of equi-rotating rollers (2, 2') configured to receive a front edge of a printed substrate (S), to make it advance in said advance direction, to draw the printed substrate (S) into a defined roll-up gap between the equi- rotating rollers (1, F, 2, 2') and to wind the printed substrate (S) onto itself in the roll-up gap to form a reel, wherein the equi-rotating rollers of said first pair (1 , 1') have respective rotation axes fixed to said frame and the equi-rotating rollers of said second pair (2, 2') have respective rotation axes fixed to said sliding trolley (3) so as to be able to displace along said advance direction with respect to the first pair of equi-rotating rollers (1, F ), a motor assembly (M 1 - 1', M2-2’), functi onally connected to said rollers ( 1 , F, 2, 2') to make them all rotate in the same direction, a motor (M3) configured to position said trolley (3) in an adjustable starting position with respect to said frame and to move the sliding trolley (3) in both directions along said advance direction, a microprocessor unit for controlling said motor (M3), the method including the following operations: by means of said microprocessor unit, positioning said trolley (3) in said starting position; starting said motor assembly (Ml-F, M2 -2') to wind said printed substrate (S), with said motor (M3) moving the trolley (3) and with said microprocessor unit adjusting the speed of movement of the trolley (3) and one of its positions while the reel is being wound.

6. The method according to claim 5, comprising the operation of regulating the movement speed and the position of the trolley (3) according to:- a feed speed of the printed substrate (S) towards the rolling space,- a rotation speed of said equi-rotating rollers (1 , F, 2, 2'),- said adjustable starting position,- a thickness of the printed substrate (S),- a variable parameter or "compression curve", which defines a variation of thecompression provided by the trolley on the reel at each instant of its winding,7. The method according to claim 5 or 6, comprising the following steps: establishing a starting position of said trolley (3) as a function of a thickness of the printed substrate (S) to be wound; starting said motor assembly (Ml-1', M2 -2') to wind a first turn of said printed substrate (S) on itself; as the printed substrate (S) is wound up on itself, move the trolley (3) with a movement speed, in which said microprocessor unit determines the movement speed and the position reached by this movement at every instant of the winding process so that:- it is equal to a speed with which an outer diameter of the reel of printed substrate (S) increases in said roll-up gap, to maintain a constant winding tension of the printed substrate (S), or- it is greater than the rate at which an outer diameter of the printed substrate roll (S) increases in said roll-up gap, to allow the first turn of the printed substrate (S) to expand and increase an inner diameter of the roll, or- it has been specified by the user in order to regulate the compressive force of the reel generated in a variable way during each instant of the winding process.

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