Description of the invention

Technical field of the invention

The present invention refers to a device for forming book blocks with two by two glued internal pages and a method for formation thereof according to the preambles of claim 1 and claim 7.

Technological background

Therefore _» the book blocks subject of reference of the present invention are known book blocks for children books, in which internal pages of the books are glued to each other two by two while the external pages are subsequently glued in a cover so that also the first and the last page of these book blocks, after applying the cover, are formed by two sheets glued to each other. It is also known to provide for through openings between the pages of the book blocks, providing for the so-called "windows" which can be opened and closed in a hinge-like fashion by the children. These books for children have been produced using various technologies over more than a century, wherein the hourly production thereof, also using more modern machines, amounts to about 90 strokes or couplings of pages per minute.

These books regained popularity over the last years due to the fact that this kind of books are now also used as wedding albums, picture albums, catalogues, and so on and so forth, hence the demand for these books with glued pages two by two, both made of paper and synthetic material has been increasing with time, wherein the grammage and the thickness of the sheets used are very variable. By way of example, the sheets made of paper and synthetic material used may have a grammage ranging between 130 and 2000 g/m2 and a thickness ranging between 0.3 and 4 mm.

Figures 1 and 2 schematize the principle of formation of such books, wherein in figure 1 there are illustrated four sheets A, B, C, D folded on themselves with folding P facing downwards and each defining two pages Al , A2; B l, B2; C I , C2; DJ , D2, wherein the external sides of the pages B l, Cl and Dl are provided with an adhesive, as illustrated with the thickest line. When producing the relative book block 2, fig 2, the single sheets A, B, C and D are further folded on themselves closing and against each other, hence, observed in the direction of the arrow F, the front side Bl with the agent for bonding the sheet B is bound to the rear side without the agent for bonding the page A2, the front side of the page C I with bonding agent is bound to the rear side of the page B2 wjthout the bonding agent and the front side of the page Dl with bonding agent is bound to the rear side of the page C2, thus allowing forming the book block Z with single front Al and rear D2 pages and double internal pages A2-B 1 ; B2-C 1 and C2-D1 . A cover U, indicated with a dashed line, is then glued on the external pages Al and D2 so as to also have said first and last page in form of a doable page, i.e. U-A l and D2-U.

In the known technologies for forming these book blocks for children books, the low productivity of the relative machines and processes is disadvantageous, also comprising single and intermittent movements, often still carried out manually, hence requiring a considerable use of manpower. Many stacking devices are known for continuously create stacks of sheets like napkins, envelopes or the like by means of a starwheel assembly with one or two separators cooperating with the latter, wherein said sheets are received with clearance in circular slots of said starwheel assembly. However, the known stacking devices can not be utilized for stacking pre- folded and glued sheets of thin cardboard for forming, for example, book blocks having two by two glued internal pages.

The document JP 49 002265 A shows V-like prc-folded sheets 5, 6 housed with clearance in pockets 20b defined by curvilinear flexible blades 21 in two starwheeis 20, wherein said pre-folded sheets are discharged in their V-like open form in a vertical position by stroking on an horizontal extraction table associated to said starwheeis 20, and wherein the pushing action of the single extracted sheets forward is obtained by means of a pushing piston-cylinder unit 42 acting on the lower part of said open V-like pre-folded sheets near the fold of the latter.

The document US 3 537 362 A discloses a rotary creasing and delivering means for rapid creasing and delivery of envelopes in a "wide range" forming machine having a spiral wheel assembly formed by three spiral wheels provided with a plurality of arcuate slots for the transport of the envelopes in a vertical position on horizontally moving belts in a direction away from the machine, wherein the accumulated envelopes are then removed by an attendant and packed, wherein the envelopes may have flaps folded or extended. The process of envelope formation and deliveiy from the machine may take place at a very high rate of speed indeed, however the proposed means can not be used for stacking sheets of thin cardboard provided with glue and in fact such utilisation is neither described, nor suggested or illustrated in the whole document.

The document US 2003/082044 Al discloses an apparatus and method for discharging sheets from a starwheel assembly utilized for creating stacks of a desired number of sheets in horizontal or vertical position without interrupting the rotation of the starwheel assembly, wherein in this apparatus the sheets are housed freely, that is with clearance, in circular slots respectively defined by two adjacent fins of said starwheel assembly. A friction coupling between a sheet and the slot receiving the latter is neither described nor suggested or illustrated in the whole document, wherein the discharging phase of the sheets in vertical stacks takes place by gravity. Folded sheets provided with glue would come into contact with the slot walls and make the latter dirty, wherein the sheets will lose the correct register position and said slot walls should be cleaned.

The document EP 0 553 724 A l discloses a method and device for producing stacks of folded or not-folded sheets 1 like napkins, wherein said sheets 1 are held by means of grippers on a rotating delivering wheel 3 which transfers said sheets 1 in a vertical position on an horizontal table 4. With said delivering wheel 3 cooperate two mechanic components 7 and 5 which with alternative movements realize the coupling of the sheets 1 for forming the stacks of sheets 1 to be further delivered to a packaging machine. The disclosed stacking device is not able to form stacks of sheets provided with glue as well as to press said sheets on the whole surface of the latter in order to obtain a stable coupling of the sheets in the correct position in the stack.

Summary of the invention

This invention aims at providing a device and a method for forming book blocks with two by two glued pages of the indicated type, free of the drawbacks observed in the prior art and capable of allowing a quick and continuous production of the book blocks with a device that is simple to manufacture and reliable in use, as well as capable of being quickly The aforementioned object, according to the invention, is attained through a device and a method for forming book blocks with glued pages having the characteristics of claims 1 and 7. sheets 1 are held by means of grippers on a rotating delivering wheel 3 which transfers said sheets 1 in a vertical position on an horizontal table 4. With said delivering wheel 3 cooperate two mechanic components 7 and 5 which with alternative movements realize the coupling of the sheets 1 for forming the stacks of sheets 1 to be further delivered to a packaging machine. The disclosed stacking device is not able to form stacks of sheets provided with glue as well as to press said sheets on the whole surface of the latter in order to obtain a stable coupling of the sheets in the correct position in the stack.

Summary of the invention

This invention aims at providing a device and a method for forming book blocks with two by two glued pages of the indicated type, free of the drawbacks observed in the prior art and capable of allowing a quick and continuous production of the book blocks with a device that is simple to manufacture and reliable in use, as well as capable of being quickly adapted to books formed differently.

The aforementioned object, according to the invention, is attained through a device and a method for forming book blocks with glued pages having the characteristics of claims 1 and 7. Further developments are observable from the dependent claims of the device and the method.

Several important advantages are obtained through the device and method indicated above.

Firstly, the operation is carried out with a horizontal current of spaced sheets, more or less partly prc-folcled on themselves, with forward folding, as illustrated, or also with a front or lateral folding, in the direction of supply, with or without glue on the upper side thereof, depending on the book block to be produced, hence allowing a supply obtainable continuously and at high and variable speed, as well known to a man skilled in the art. The sheets are supplied tangentially to a transfer drum formed by at least two identical wheels, spaced and with a plurality of circumferential pockets open towards the external and with arc-like development in the opposite direction with respect to the rotation of said drum, hence there can be obtained a quick and continuous supply of the single sheets from a substantially horizontal position in a substantially vertical position, with subsequent automatic extraction stroke on an associated extraction table and with simultaneous pressure approaching of the respective last sheet extracted, or discharged, using the wheel and the sheet extracted against the respectively preceding sheet of the book block being formed, wherein said succession of steps occurs without requiring any manual intervention, and wherein the speed of supplying the current of pre-folded sheets and the speed of rotation of the transfer drum can be easily synchronised with respect to each other using means well known to a man skilled in the art, for example brushless motors. The disclosure of the invention allows obtaining an hourly production amounting to about 1200 strokes or coupling of pages per minute, or more than 10 times greater than highest production levels that can be obtained using the prior ait methods. A further advantage should be observed in the provision of simple means for pre-folding the sheets during the entrance in the pockets, which can be easily adapted to the format of the supplied sheets.

Another advantage should be observed in the use of simple and known guiding and jogging means associated to the extraction table and guaranteeing the correct and automatic formation of the book blocks, or of the pack of book blocks being formed.

Still another advantage should be observed in the correct insertion of the folded sheets in the pockets of the drum and maintaining the correct positioning of the sheets folded inside the pockets during the transfer thereof following a housing with slight friction or shape-coupling between the sheet folded on itself and the pocket housing it, hence allowing operating with the high performance indicated amounting to about 1200 strokes or couplings of pages per minute.

A further advantage of the device according to the invention lies in the fact that in case of extremely, wide formats of sheets the drum may comprise more than two wheels identical to each other, for example three wheels, for example supported spaced, slidable and lockable on an actuation shaft or sleeve.

Still another advantage of the invention lies in providing a plurality of wheels with a development of the circumferential pockets obtained according to the format, and possibly the materia!, the sheets, the wheels being quickly interchangeable and replaceable on the driving shaft, hence the machine can be quickly adapted to changes of the sheet format.

Brief description of the drawings

Further characteristics, advantages and details of the device and the method for forming book blocks with two by two glued internal pages will be more apparent from the description that follows and from the attached drawings, which illustrate a preferred embodiment and to which reference shall be made for any detail not illustrated in a sufficiently detailed manner in the description. In the drawings:

figures 1 and 2 schematically show the known principle of forming book blocks for children books,

figure 3 schematically shows a top perspective view of the transfer drum of the sheets and the associated extraction table of the device according to the invention,

figure 4 schematically shows an analogous perspective view with an extraction table provided with jogging side boards,

figures 5 and 6 respectively schematically show the detail E of figure 4 in enlarged scale with front view and top perspective view,

figure 7 schematically shows a front perspective view of the device according to the invention,

figures 8 and 9 respectively schematically show the detail G of figure 7 in enlarged scale with top perspective view and in front view, and

figure 10 schematically shows a top assembly view of the group formed by the transfer drum and by the associated extraction table.

Description of the preferred embodiment In the various figures, illustrated in different scales for a better illustration and understanding of the parts and details of the device according to the invention, identical parts have the same reference numbers.

Figures 1 and 2 have already been described in the introduction.

First, reference is made to figure 3, in which the device according to the invention for forming book blocks with two by two glued internal pages is indicated its entirety with 1. The device 1 comprises, in the illustrated example, a transfer drum 2 formed by two identical wheels 3, 4 mounted spaced on a driving shaft 6 and having in the external circumferential part a plurality of arc pockets 7 curved from inside towards the external in opposite direction with respect to the direction of rotation F l of said wheels 3, 4 and which are separated from each other respectively by means of a tooth 8 substantially sickle-shaped, wherein each tooth 8 has a tip portion 9 projecting with respect to the rear tooth 8 and with which it fonns the port 10, open tangentially, of the pocket 7 defined from time to time by said adjacent teeth 8.

As observable from the figures, the pockets 7 have a narrow, long and arched development for housing a folded sheet 1 1 from time to time, as described hereinafter. The distance between the two wheels 3 and 4 on the shaft 6 is provided having a smaller width T of the folded sheets 1 1 to be transferred, as outlined more in detail hereinafter.

As illustrated in figure 10, to the drum 2 there is associated - front-wise - a substantially horizontal extraction and collection table 12, and more precisely so that the front abutment projection thereof 13 penetrates between the wheels 3 and 4 and serves as an abutment on which the folded sheets abut so as to be stopped and extracted from the drum 2 which rotates continuously. In addition, figure 10 shows that the table 12 may also have - front-wise - two optional lateral abutment projections 12a, on which the external areas of the folded sheets 11 abut and prevent a possible deformation of the sheets during abutment, for example in case of sheets having a low thickness.

Particularly, as observable in figure 7, along the lateral sides of the extraction table 12 there are arranged two known jogging side boards 14, which are mounted moveable in the longitudinal and transverse direction on the extraction table 1 2. Said side boards 14 have - at the ends - strips 14a slightly folded towards the external in a fashion similar to an introduction strip. Figure 3 also shows means 16 for the abutment and curvature of the sheets 1 1 to be handled and obtained, in the illustrated example, in form of two rollers 17 mounted freely rotatable and moveable on a shaft 1 8 extending transversely with respect to the drum 2 and supported on the framework of the machine, in a manner not illustrated further and moveable in the horizontal plane, as indicated by the double arrow F2.

According to the method of the invention the sheets 1 1 - pre-folded on themselves for the formation of the book blocks - are supplied with a forward folding 19 spaced uniformly with respect to each other in a substantially horizontal current according to the arrow F3 in a tangential plane passing through the ports 10 of the pockets 7 at the upper area of the drum 2, as illustrated in figure 3. In figure 3 there are indicated, by way of example, four folded sheets 1 1 provided for forming a book block 21. As observable, the first folded sheet I and the last folded sheet IV on the upper face thereof are without glue, while the intermediate sheets It and III have glue applied thereon, as il lustrated by way of example with solid or dashed lines, wherein in the sheet II the area around the opening or window 22 is without glue. The application of glue occurs upstream of the device 1 according to the invention and the application of glue shall be provided from time to time on the folded sheets in the internal area thereof, i.e. having a width smaller than the distance between the two wheels 3 and 4, so as not to dirty the teeth 8 of said wheels 3 and 4 and it may occur in proximity of the drum 2, in a non-illustrated manner.

The current of folded sheets 1 1 supplied to the drum will obviously comprise a succession of folded sheets from I to IV for the production of the number provided with book blocks 21 containing said folded sheets from 1 to IV, wherein the sequence of sheets 1 1 in the supplied current of sheets may be varied at will at any time for forming book blocks 21 having a different number of pages, without interrupting operation.

In the method proposed in the step for horizontally tangentially supplying folded sheets 11 to the drum 2 there follows a step of transferring the folded sheets from the substantially horizontal plane thereof to a substantially vertical position, which is obtained by rotating the drum 2. In the step of substantially vertically positioning the folded sheets 1 1 there follows a step of tangentially discharging the same from the drum 2 and the subsequent advancement of the preceding sheet 1 1 through the combined action of the impact of each sheet 1 1 with the folding 19 thereof on the abutment edge 13 of the extraction table 12 and the action of pushing forward through the subsequent discharged sheet and through the external edge of the subsequent tooth 8 at the end portion 9 thereof. This pushing action simultaneously determines a gluing step with accurate pressure of each folded sheet on the opposite face of the preceding folded sheet, or without any friction between the two sheets 1 1 to be glued, with continuous formation of the book blocks 21 provided for, or the pack 23 of book blocks 21 formed progressively.

Figure 3 indicates - for the sake of clarity through a slight clearance - the succession of the single book blocks 21 ; obviously this clearance does not actually exist in that the single book blocks 21 lie against each other without bonding in that the respective first and last face thereof are without glue.

It should be observed that the single folded sheets 1 1 - upon the entry thereof into the pockets 7 - are substantially flat and thus enter for a first part with clearance, i.e. without friction, directly in the respective pocket and subsequently with a slight pressure action through which said folded sheets are slightly curved and housed thus with a slight geometric constraint, or friction, which confers the same a correct and stable positioning during transfer from the horizontal position to the vertical one, wherein the mentioned rollers of pre-curvature 17 facilitate a pre-curved insertion of the sheets 1 1 in the pockets, hence facilitating a safe and reliable introduction of the folded sheets 1 1 even in the most advanced curved area of said pockets 7.

The formation of a correctly jogged pack 23 of book blocks 21 is obtained by the presence of the mentioned jogging side boards 14 with strips for the introduction of ends 14a, whi ch facilitate both the perfect positioning of the folded sheets before the gluing action, as well as the picking up of the book blocks 21 on a conveyor belt or through a gripper, per se known and not illustrated.

The figures, particularly figures 5 and 9, show that the extraction table 12 is provided slightly inclined upwards, and this with the aim of offering the pack 23 being formed a greater resistance against the advancement or sliding thereof on the table 12 and, by consequence, with the aim of ensuring an ideal bonding - between the pages provided with glue and the respecti ve front page subject of the gluing - of the preceding sheet 11 in the direction F4 of formation of the pack 23. The table 12 is supported in an oscillating and adjustable fashion in the framework of the device 1 so as to adapt the inclination thereof to the characteristics of the sheets 11 handled from time to time, wherein there is provided an oscillation for example in the range between 1 - 15°, depending on the material forming the folded sheets 1 1 .

The illustrated method may also be executed using prc-folded sheets 11 supplied with rear folding, in the direction of supply, or laterally.

The structural and functional description, as well as the method of formation of book blocks continuously and at high speed according to the invention clearly reveal that the proposed device and method allow attaining the object and advantages indicated above.

The disclosure subject of the present invention also includes providing for transfer drums formed by two or more transfer wheels previously fixed on a sleeve to be subsequently simply inserted on the driving shaft or, provide for the wheels 3 and 4 as well as metal made of fibre-reinforced synthetic materials, or replace the table 12 with a variable speed conveyor belt, or associate to the table 12 or the conveyor belt for discharging the book blocks a lateral gripper for the programmed picking up of the formed book blocks, or provide for pre-curving rollers activated to guarantee a uniform and repetitive insertion of the folded sheets in the pockets, and so on and so forth, without departing from the scope of protection of the present invention.

In practice, the invention may be subjected - by those skilled in the art - to further modifications or variants, or differently combine the proposed characteristics, still without departing from the scope of protection of the invention as claimed in the following claims.