DEVICE AND PROCESS FOR PIVOTING FLAT ELEMENTS, SUCH AS BOOKS, MAGAZINES OR THE LIKE, ON A PLANE

Description

The present invention is related to a device and to a process for pivoting flat elements like books, magazines and the like on the plane wherein they are lying, through adjacent conveying systems having differentiated speeds, and a stacking apparatus incorporating said device for pivoting as well.

In the state of the art, devices as above specified are known, functioning with adjacent and motorized roll planes so as to be operated with differentiated speeds. The flat element to be pivoted is delivered on the conveying system at the separation line between the adjacent systems, thereby both the systems act on it. The speed difference causes a torque determining the rotation of the flat element

Such systems, e g. disclosed in the European patent application No. EP 1,666.236 A1 and in the U.S. Patent No. 6.164,431. are typically used in apparatuses for the folding and the glueing of punched cardboards, which have to be pivoted of 90° or 180° with respect to the conveying direction, to let folding plows and glue deposition devices to operate on the four sides of the punched blank and according to directions orthogonal to each other

Instead, particularly in the field of publishing, a problem is felt referred to books and magazines, even if the same problem may be encountered also in other fields Such problem is related to the 90°- or 180°-rotation of a flat element in alternate opposite way, clock-wise and counter clock-wise or vice-versa.

As a matter of fact, for stacking books or similar flat elements not having a uniform thickness it is required to have them alternatively pivoted so as to compensate the thickness differences along the stack height.

Now, such operation is carried out manually, and this constitutes a limit in the stacking rate and, more generally, in the manufacturing rate of printed items to be stacked for having them either stored or dispatched

The technical problem underlying the present invention is to provide a device and a process allowing to obviate to the drawbacks mentioned with reference to the prior

art

Such a problem is solved by a device as above specified, comprising at least one module having a pair of side-by-side placed conveying systems so as to produce a sliding plane and separated by a separation line, allowing a flat element to be delivered at said separation line to have respective portions thereof touching each conveying system, characterized in that it compπses

* respective independent driving means for each conveying system, fit to cause respective different sliding speeds,

* means for generating an input signal related to the introduction of a flat element on said sliding conveyor plane, and

* a control system receiving said input signal and varying said sliding speeds accordingly wit h respect to each other, so as to obtain a rotation of following flat element according to alternate rotation directions

The same problem is also solved by a method as above specified, comprising the steps of

* providing at least one pair of side-by-side placed conveying systems, so as to produce a sliding conveyor plane, and separated by a separation line, each system comprising independent dπving means causing a respective sliding speed of the conveying system,

* delivering flat elements in a sequence at said separation line, so as to have portions thereof touching both said conveying systems, and

^í differentiate, for each delivered flat element, the respective sliding speeds so as to obtaining for following flat elements, different rotation directions

The main advantage of the device and of the process according to the present invention lies in allowing the alternate rotation of flat elements, achieving the alternate stacking thereof, feeding the stacking itself through only one conveying line

The present invention will be disclosed hereinafter according to an embodiment thereof, together with some implementation conditions thereof, provided with and

exemplificative and non-limitative purpose referring to the annexed drawings wherein'

* Figure 1 shows a whole perspective view representing a stacking apparatus for flat elements as books, magazines and the like, incorporating a delivery station, a device for pivoting said flat elements according to the invention and a stacking station;

* Figures 2A, 2B, 2C e 2D illustrates different operation steps of the device for pivoting of Figure 1, in a partial representation of the apparatus of Figure 1 ; and

* Figures 3A, 3B ₁ 3C e 3D illustrates different stacking operation steps, with reference to the stacking station and to the device for pivoting of Figure 1.

In connection with Figure 1 , a stacking apparatus for flat elements as books, magazines and the like is generally indicate as 1, and it is fed e g by a tnmming machine cutting the margins of books and magazines.

Books and magazines are provided with a binding and possibly with paperback, and therefore the binding side is thicker than the body of the flat element

For this reason, it is not possible to stack the elements always overlapping the binding sides thereof, because the stack would be inclined by the thickness differences

Instead, the elements have to be pivoted while they are fed from the trimmer, or anyway from the station preceding the stacking apparatus, 90" or 180° so as to overlap the binding side of an element with the opposite side of the subsequent element and so on, obtaining the substantial balance of the thicknesses.

Shortly, the flat elements here treated by the device and through the method herein disclosed will be referred as books, indicated as B.

The apparatus 1 comprises a delivery station 2, having a conveyor belt 3 or another equivalent system delivering books B to be stacked

Generally, the books B are delivered positioned according to the same direction, continuously or intermittently. The delivery station 2 can therefore operate as a buffer. If the books are received according to random directions, delivery direction

recognition means will be provided, and a counter of the books received by the station 2 itself.

The books B coming from the conveyor belt 3 are stopped against a stop element 4, and a preliminary stack is formed at the latter on a supporting plane 6 Preferably, 5 the books 6 arrive with the margin of the binding P faced to the stop element 4 and towards the subsequent pivoting device, globally indicated as 20.

The delivery station 2 comprises means for delivering books in the following device for pivoting 20, having a pushing member 18 operated in a conventional manner according to a pre-set feeding rate, acting on the book B at the bottom of the stack lϋ 5, pushing it in such a way that the binding margin P thereof is introduced between a pair of horizontal extracting rolls 7

The upper extracting roll 7 is provided with a rise-and-fall device 8 causing the raising thereof, when the margin P of the book B is introduced, and the lowering thereof immediately thereafter, so as to have the body of the book B firmly kept 15 between the rolls. Such an adroitness prevents the binding margin P, having a slightly higher thickness, to be squeezed and then damaged by the rolls 7

The rolls 7 and the up-and-down device 8 are conventionally driven synchronously with the pushing member 18

The stack 5 could have a variable height depending upon the feeding rate of the

20 books B on the stack 5 and by the delivery rate of the books B on to the device for pivoting 20. If the feeding rate is no constant, the presence of the stack 5 provides compensation. However, the delivery station can be provided with means for detecting the number of the books B within the stack and/or the height of the stack 5 so as to stop the feeding of the books B to the stack beyond a predetermined

25 height

In a preferred embodiment, the conveyor belt 3 is vertically movable, so as to follow the height of the stack and to deliver the books substantially at the top of the stack 5.

As previously mentioned, the device for pivoting 20 receives books B to be pivoted. 30 according to a predetermined direction by means for delivering books 18, 7 ^' , 8

At the delivery station 2, the device for pivoting comprises a first module 21 having a respective pair of side-by-side placed conveying systems, indicated as 22 and 23, so as to result in a sliding conveyor plane and separated by a separation line 24

In the present embodiment, each conveying system 22, 23 is composed by a s respective roller table, i e by an assembly of conveyor rolls 9 arranged aligned to each other and lying on a plane substantially corresponding to said sliding conveyor plane

Particularly, the rolls 9 of the present embodiment are substantially perpendicular to said separation line 24 which is in turn substantially parallel to the conveying Ui direction

The first module 21 then ha san end arranged at said means for delivering 18, 7, 8 and said extraction rolls 7 are substantially parallel to the conveyor rolls 9

Therefore, in the present embodiment, the binding margin P of each book B is delivered parallel to said conveyor rolls 9, and orthogonal to said separation line and H to the conveying direction as well

Hence, for producing a supeπmposition of books 9 alternatively pivoted of 180° to each other, it is sufficient to pivot each delivered book B of 90° clockwise and counter clockwise alternatively At the end of the rotation imposed by the device for pivoting 20, the binding margins P are substantially parallel to the conveying 20 direction

Anyway, it is understood that the device 20 can compπse different kinds of sιde-by- side placed conveying systems, e g two side-by-side placed conveyor belts, two sliding planes formed by a plurality of belts and so on, as long as each conveying system results in a conveyor plane on which the surface on a flat element is rested

5 To meet contingent needs, even the position of the conveyor rolls may be modified, e g they may be tilted with respect to the conveying direction, possibly herringbone arranged

At said end, the device for pivoting 20 compπses means for generating an input signal for a book B or for any other flat element delivered to said sliding conveyor 0 plane

In the present embodiment, said means for generating an input signal comprises at least one optical sensor 25, which is conveniently placed above the separation line 24 at the extraction roll 7 Such sensor can be placed on a bridge 26 supported by a pair of posts 27 arranged at the sides of the module 21.

The first module 21 comprises respective driving means 28, 29 independent for each conveying system 22, 23, apt to impose respective and differentiated sliding speeds

In the present embodiment, each conveyor roll 9 is driver, and none of them is idle The driving is realised by a kinematical chain comprising driven pulleys 10 at the ends of each conveyor roll 9, and by a belt 11 in turn driven by driving pulleys 12, operated by a first gear 13 receiving the motion through a chain 14 from a second gear 15, in turn connected to an electric motor 16 through a gear box 17

According to a preferred embodiment, the motor 16 can be supplied varying the voltage, the intensity and/or the frequency, to cause the variation of the rotation rate of the respective conveyor rolls 9 and hence of the conveying speed.

Alternatively, further means for varying said speeds can be provided, e.g of the mechanical type.

Through said means for delivering 18, 7, 8, each book is delivered at said separation line 24, to have respective portions thereof touching each conveying system, i.e. the conveyor rolls 9 driven to a rotation speed that, thanks to the driving means 28, 29 independent upon each other, can be different from portion to portion of the same flat element, thereby producing a dπving torque applied to the flat element casing the rotation thereof in a certain direction

The device 20 further comprises, for the first module, a respective first control system receiving said input signal from the optical sensor 25 and consequently varying said sliding speed with respect to each other, so as to produce the rotation of subsequent flat elements according to alternate rotation directions

In particular and for an exemplificative purpose, a first book B is placed with one portion thereof touching a first conveying system 22 of the module 21 , conventionally indicated as right system if seen from the delivery station 2, and with another portion touching a second conveying system 23, conventionally indicated as

left.

If the sliding speed of the left conveying system 23, i.e. the rotation rate of the corresponding conveyor rolls 9, is greater than the sliding speed of the right system 22 (Figure 2A), the book B pivots counter clockwise In the opposite condition (Figure 2B with reference to first module 21), the rotation is clockwise.

For each delivered book B, the control system varies the sliding speed of the conveying systems 22, 23 such that the speed of the first system is greater than the speed of the second one, then lower, then greater again and so on, causing alternate rotation directions following to the generated input signal.

It is understood that, in consideration of equal delivery rate and for the same book B distinguished by shape, whole surface , finishing of the touching surface and weight, the ratio between each single sliding speed is constant Such parameters, i.e the sliding speed and the above ratio, is determined on the basis of the above cited features of the flat element influencing the torque applied to the element itself, of the required delivery rate, of the length of the module and, as it can be easily understood, of the physical parameters of the conveying system as well, i e of the conveyor rolls 9, e g diameter, superficial finishing and so on

According to the present embodiment, the device for pivoting 20 comprises a second module 31 and a third module 41, completely similar to the first module 21

Therefore, the second module 31 has a respective pair of side-by-side placed conveying system, indicated as 32 and 33, separated by a separation line 34, composed by a respective roller table of conveyor rolls 9 perpendicular to the separation line 34

The second module 31 has a proximal end arranged at the distal end of the first module, so as to receive books therefrom

Also in the second module 31 , the device for pivoting 20 comprises means for generating an input signal for a book B, comprising in turn at least one optical sensor 35 placed vertically above the separation line 34, arranged on a bridge 36 supported by two posts 37 placed at the sides of the second module 31.

Hence, the second module 31 comprises respective driving means 38, 39

independent for each conveying system 32, 33, apt to determine respective differentiated sliding speed as in the first module 21.

Further, the device 20 comprises, for the second module 31 as well, a respective second control system receiving said input signal from the optical sensor 35 and varying consequently said sliding speeds with respect to each other, so ad to produce a rotation of the subsequent flat elements according to alternate rotation directions

Moreover, the third module 41, wholly similar to the previous ones and arranged in line with the second module 31 at the distal end thereof, has a respective pair of side-by-side placed roll conveying system, indicated as 42 and 43, separated by a separation line 44 The third module 41 further comprises means for generating an input signal for a book B, comprising in turn at least one optical sensor 45 placed vertically above the separation line 44, arranged on a bridge 46 supported by two posts 47 placed at the sides of the second module 31

Hence, the third module 41 comprises respective driving means 48, 49 independent for each conveying system 42, 43, apt to determine respective differentiated sliding speed as in the first module 21 and in the second module 31

Further, the device 20 comprises, for the third module 41 as well, a respective second control system receiving said input signal from the optical sensor 45 and varying consequently said sliding speeds with respect to each other, so ad to produce a rotation of the subsequent flat elements according to alternate rotation directions.

In the present embodiment, the respective separation lines 24, 34 and 44 are perfectly aligned, determining a single separation line.

Therefore, it is understood that the rotation of a single book B can be distributed along more modules, as in the present embodiment wherein the modules are three

At the passage of a book B from a module to another one, thanks to the respective optical sensor of the receiving module, the sliding speed of the conveying systems of the latter module can be varied to keep unchanged the rotation direction from the previous module which, receiving the following book, can vary the conveying speeds thereof for causing the opposite rotation direction

In such a way, in the present embodiment, the first book finishes the counter clockwise rotation thereof of 90° in the third module 41 while, in the second module 31 , the following book B is already present and being pivoted according to a clockwise direction, and in the first module 21 a subsequent book B is delivered and pivoted counter clockwise (Figure 2C)

When the first book B is expelled from the device 20 (Figure 2D), the first module 21 is receiving a fourth book B to be pivoted clockwise and so on

It is easily understood that the number of the modules and their respective length can be selected in order to face with different contingent operation needs. For instance, for high delivery frequencies, further modules can be add, possibly increasing the respective sliding speeds but decreasing the ratio between sliding speeds of side-by-side placed conveying systems, to prevent the book B under goes excessive stresses.

According to a variant, between adjacent modules a sliding area having no sliding speed differences can be provided, particularly for varying the speeds of conveying systems in one module without having other books entering or exiting just in the instant of the variation, an instant having an unavoidable measurable length

In this connection, it is noted that the means for generating an input signal of a flat element on said sliding conveyor plane can be arranged above said sliding area, and in any case they may not be provided at the entrance of each module.

Anyway, it is understood that the device according to the present invention can be programmed for pivoting each delivered book or other flat element according to an angle which can be set upon demand, variable from book to book

For instance, it is possible to apply a rotation of 0° to a first book, of 90° clockwise to a second book, a rotation of -90° counter clockwise for a third book, a rotation of 180° for a fourth book and the commencing again the same cycle, obtaining a stack wherein the binding margin is alternatively present on all the four sides of the final stack.

According to another example, the books can be pivoted two by two, three by three and so on according to opposite rotation directions

Further angles may be set for pivoting non-rectangular flat elements or for obtaining any required superimposition

With reference to the embodiment of device for pivoting and of apparatus for stacking herein described, a process for pivoting flat elements like books, magazines and the like according to the invention is disclosed in the following, on a plane wherein said element lye, determined by the side-by-side arrangement of said conveying systems 22, 23, 32, 33, 42, 43

They operate with differentiated speeds and each of them acts on a portion of the book B, to impart a torque.

The outstanding process comprises the step of providing at least one pair of said conveying systems, arranged side by side so as to produce a sliding conveyor plane

Such conveying systems are separated by a separation line 24, 34. 44 longitudinally crossing said conveyor plane according to a conveying direction

Each system comprises independent driving means causing a respective sliding speed of the conveying systems. Therefore, one side of the sliding plane has a greater sliding speed and the opposite side has a lower sliding speed.

Flat elements like books B are delivered in a sequence at said separation line 24, so as to have portions thereof touching both said sliding conveyor planes The speed difference, as explained above, determines a rotation.

For each book it is possible to differentiate, for each delivered flat element, the respective sliding speeds so as to obtaining for following flat elements, different rotation directions. Therefore, alternating sliding speed from one side to the other, alternate rotations are produced.

With reference to Figures 1 , 3A, 3B, 3C e 3D, a stacking station 50 will be described hereinafter, arranged at the tail of a device for pivoting according to the invention, within the stacking apparatus described herein.

The station 50 comprises a guide system 51 with conveyor belts collecting each book B from the end module 41, without modifying the orientation thereof The book B is sent to independent collection planes and vertically movable of the stacking

station 50.

In the present embodiment, the stacking station 50 comprises two collection planes 52, 53. Each collection plane comprises in turn a pair of tilting supports, faced to each other and movable from a horizontal position, wherein they result in a collection plane, to a vertical position wherein the leave their corresponding section open

Each support 54 is mounted on a pair of belts 55 extending between toothed wheels 56. Therefore, on each side of the collection planes 52. 53 the station 50 comprises four belts 55 alternatively cooperating with a respective support 54

The belts corresponding to the same collection plane are driver by the same kinematical chain, adjustable through suitable wheels 57.

In a lowered position with respect to the race of the supports 54, the station 50 comprises a conveyor line 58 with pins 59, apt to push away the book stack once it is produced

The operation of such station 50 is described hereinafter

In a first configuration (Figure 3A). the supports 54 of the first collection plane are placed aligned to the guide system 51 and receive from the latter a first book B Proceeding with more and more incoming books with the alternated binding margin position, the facing supports 54of the same collection plane are lowered, so as the last received book B produces a resting plane at the following level (Figure 3B).

The lowering of the supports 54 is synchronised following to a passage detection system 60 at the entrance of the station 50, i.e. at the end of the device for pivoting 20, provided with an optical sensor arranged on a bridge 66 in turn supported by posts.

It is understood that the optical sensor 65 for the present stacking station 50 can be positioned at another spot of the book path as well, e.g. at the guide system 51

Once the book stack reaches the required height, i.e. it contains the required number of books, the support 54 are lowered to the level of said conveyor line (Figure 3C), while the supports 54 of the second collection plane 53 are positioned so as to receive books from the guide system 51.

Then, the already formed stack is pushed away by the conveyor line 58. the second collection plane 53 is lowered while it receives more and more books B and the supports 54 of the first supporting plane are raised again by the motion of the loop of the belts 55 (Figure 3D)

To the above disclosed device for pivoting and related method for pivoting, and to the apparatus incorporating said device for pivoting a man skilled in the art, to meet further and contingent needs, may introduce several additional modifications and variants, anyway all falling within the protection scope of the present invention, as defined by the annexed claims.