EP2629983B1

EP2629983B1 - Adhesive delivering head for binding machines and machine incorporating the head

Info

Publication number: EP2629983B1
Application number: EP11793491.9A
Authority: EP
Inventors: Roberto Raccanello
Original assignee: KGS SRL
Current assignee: KGS SRL
Priority date: 2010-10-20
Filing date: 2011-10-20
Publication date: 2015-02-11
Anticipated expiration: 2031-10-20
Also published as: WO2012052959A9; EP2629983A1; ITVI20100285A1; IT1403175B1; WO2012052959A1

Description

Field of the invention

The present invention finds application in the field of bookbinding equipment and particularly relates to a fluid or semifluid adhesive delivering head for binding machines designed for binding sheet elements in blocks, such as blocks of paper sheets for books, agendas, albums or the like.
The invention further relates to a binding machine incorporating such adhesive delivering head.

Background art

As is known, in the bookbinding art, devices are used for joining blocks of adjacent sheet elements, which have a back and an outer cover.
For instance, the sheet elements may be sheets of printed or blank paper of various sizes, which are bound with a more rigid cover to form books, catalogs, notebooks or the like.
Particularly, one of the most widely used techniques to form the binding consists in joining the cover to the block by applying a preset amount of adhesive along its back.
Typically, the step of applying adhesive to the block is carried out by adhesive delivering heads incorporated in machines that implement the whole bookbinding process.
It will be understood that proper binding requires uniform distribution of the adhesive all over the back surface, with no portion thereof being left free of adhesive.
A back with adhesive-free or poorly adhesive areas may cause failed local adhesion of the cover to the sheet elements, and consequent removal of the latter from the cover, thereby affecting the binding.
In an attempt to improve adhesive distribution on the back of a block, applicator devices have been developed, which are designed for calibrated, uniform delivery of a predetermined amount of adhesive.
For instance, US 4,512,945 discloses an adhesive delivering head having an adhesive collecting chamber connected to an external tank through a feed pump.
The collecting chamber is held in a supporting frame having a seat designed for passage of the block, with a delivery slot formed therein having a plurality of outlet holes.
The collecting chamber is put in communication with the holes through a passage whereat two opposite movable piston-like pressure members are located, which have sealing elements for conveying the adhesive to the outlet holes, while controlling the delivered amount.
As the blocks pass over the slot, the pressure elements move and the adhesive flows out of the holes.
A first drawback of this solution is that the delivery of adhesive through the holes is affected by any water hammer occurring due the motion of the pressure means.
Particularly, the stick slip motion of the pressure members causes discontinuous feeding through the holes and hence uneven delivery of adhesive to the back of the book.
A further drawback is that the total amount of delivered adhesive only corresponds to the desired amount if the movement of the pressure members is synchronized. This will require the provision of expensive devices for controlling the movement of the pressure means.
A further drawback is that the collecting chamber contains a considerable amount of adhesive, and that cleaning of the device requires discharge of such amount of adhesive and use of relatively large amount of cleaning liquid.
Furthermore, the amount of excess adhesive delivered through the slot may contact other external parts of the device, and cause fouling thereof.
Another considerable drawback is that the pressure members have sealing elements that cause glue leakages along the collecting chamber during movement thereof, resulting in a reduction of the amount of delivered adhesive.
US 5,129,772 discloses a further adhesive delivering head for binding machines in which the head, in a first configuration, comprises a seat for passage of the back of the block to be bound, in which seat a slot is formed to define an outlet for the adhesive.
The latter flows out of the slot through a single feeding passage.
This configuration does not allow uniform distribution of the delivered adhesive all along the slot, and will result in less than optimal block binding.
The same document also discloses a second configuration, in which adhesive is directly fed into the seat for block passage without flowing through an extrusion slot, and is distributed by a plurality of nozzles accommodated in the seat, for a plurality of adhesive beads to be applied along the edge and the side faces of the block.
As a result, the adhesive is distributed on the back in a discontinuous manner and the quality of binding is not adequate for all applications.

Disclosure of the invention

The object of the present invention is to overcome the above drawbacks, by providing an adhesive delivering head for binding machines that is highly efficient and relatively cost-effective.
A particular object is to provide an adhesive delivering head that affords even and accurate distribution of a predetermined amount of adhesive on the back of a block, while ensuring constant delivery.
A particular object is to provide an adhesive delivering head that affords highly accurate metering of the delivered adhesive, while reducing waste and simplifying cleaning operations, particularly allowing the use of a smaller amount of cleaning fluid.
A particular object is to provide an adhesive delivering head that allows removal of excess adhesive from the back of the block without fouling parts other than the adhesive delivery area.
A particular object is to provide an adhesive delivering head that has a smaller number of parts subjected to wear, which are easily replaceable.
Another important object of the invention is to provide a binding machine for binding blocks that uses such adhesive delivering head.
These and other objects, as better explained hereinbelow, are fulfilled by an adhesive delivering head for binding machines, as defined in claim 1.
With this particular configuration, the adhesive may be spread in a substantially uniform manner all along the slot, while avoiding pressure bursts.
In a further aspect, the invention relates to a binding machine for binding sheet elements as defined in claim 9, which uses such adhesive delivering head.
Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Brief description of the drawings

Further features and advantages of the invention will be more apparent from the detailed description of a preferred, non-exclusive embodiment of an adhesive delivering head of the invention, which is described as a nonlimiting example with the help of the annexed drawings, in which:

FIG. 1 is a perspective view of an adhesive delivering head of the invention;
FIG. 2 is a top view of the head of Fig. 1;
FIG. 3 is a first lateral view of the head of Fig. 1;
FIG. 4 is a second lateral view of the head of Fig. 1;
FIG. 5 is a sectional lateral view of the head of the invention, as taken along the plane V-V of FIG. 2;
FIG. 6 is a lateral sectional view of the head of the invention, as taken along the plane VI-VI of FIG. 2;
FIG. 7 is a lateral sectional view of a detail of the head of the invention, as taken along the plane VII-VII of FIG. 2;
FIGS. 8 and 9 are two sectional v

Detailed description of a preferred embodiment

Particularly referring to the accompanying figures, the adhesive delivering head, generally designated by numeral 1, may be used to spread a predetermined amount of liquid or semiliquid adhesive on the back D of a plurality of sheet elements F gathered in side-by-side relation into a block B having a thickness s.
Particularly, the sheet elements F may consist of paper sheets, either printed or blank, to form a book, a catalogue or the like.
The head 1 may be used to spread the adhesive on blocks B of various thicknesses s and various lengths.
Furthermore, the head 1 may spread heat melting adhesives of various types, such as polyurethane, hot melts and EVA adhesives, and allows delivery of adhesives with different melting points.
Furthermore, the head 1 may be incorporated in any binding machine, not shown as a whole and known per se, or may form a self-supporting station designed to be associated with one or more additional workstations of an existing machine.
The binding machine may have one or more adhesive delivering heads 1 of the invention and may include an external storage tank R and pump means P for pumping and conveying the adhesive towards the head 1, as schematically shown in Fig. 3.
According to the invention, an adhesive delivering head 1 essentially comprises a main frame 2 having a longitudinal seat 3 for guiding the back D of the block B of sheet elements F to be bound.
The seat 3 may be delimited by a pair of slides 4, 4' located on the upper surface 5 of the frame 2.
The slides 4, 44' may be movably mounted to the frame 2 to slide thereon in a direction substantially transverse T to the seat 3 to change the width w thereof.
Furthermore, for particular types of applications, such slides 4, 4' may be fixedly connected to the frame 2 to define a seat 3 having a predetermined, constant width w.
The slides 4, 4' may be moved towards and away from each other using drive means 6 associated with the frame 2 and connected to the slides 4, 4' by transmissions 7 or other mechanisms.
The width w of the seat 3 may be relatively greater than the thickness s of the block B to allow passage thereof through the seat 3.
Furthermore, the head 1 comprises a substantially transverse slot 8 formed in a portion 9 of the seat 3 for local distribution of a fluid or semifluid adhesive on the back D to be bound.
Conveniently, the slot 8 may be disposed in the frame 2 in a substantially central position.
Typically, as shown in Fig. 7, the seat 3 may be designed to hold the back D close to the slot 8, lying on the upper surface 10 of the seat 3 or slightly raised therefrom.
Preferably, the distance d between the slot 8 and the back D may be of a few tenths of a millimeter, but it may be changed by adjusting the position of the back D, i.e. by lifting the back D of the block B, e.g. using appropriate gripper means, not shown.
Alternatively, the head 1 may be associated with translation means for causing vertical translation of the frame 2 or a part thereof associated with the seat 3, which means are not shown and may be of hydraulic, pneumatic or electromechanical type.
The length g of the slot 8 may be substantially equal to the width w of the seat 3, if the latter has a fixed, predetermined value.
However, if the seat 3 is adjustable, the slot 8 will have a maximum length g slightly smaller than the maximum width w of the seat 3.
Here, any change of the width w of the seat 3 may result in a change of the length of the useful portion 11 of the slot 8.
Each slide 4, 4' may have a respective substantially vertical channel, one of them being only visible in Fig. 1 and referenced 8', which are located at the slot 8 in fluid connection therewith.
Thus, the adhesive may also flow out of the channels 8' to be spread on an edge portion of the side faces of the block B.
The amount of adhesive that can be delivered by the slot 8 may be controlled according to the thickness s of the block B to be bound and the speed at which the block B moves on the slot 8.
For constant delivery of adhesive over the back D, the flow rate through the slot 8 shall be simply increased as the speed of the block B increases.
For this purpose, controlled feeding means 12 are provided for feeding a predetermined amount of adhesive into the slot 8, which means are located below the slot 8 and upstream therefrom to cause adhesive to flow if it by a flow action from the underlying area.
According to the invention, the controlled feeding means 12 comprise a plurality of feeding elements 13, 13', 13", 13"' in fluid communication with the slot 8 and evenly distributed in a substantially transverse direction parallel to the extension of the slot 8 for spreading the adhesive in said distribution portion 9 in a substantially uniform manner.
For simplicity, one of the feeding elements, referenced 13, will be only described below, but it shall be understood that it is identical and has the same parts and functions as the others in adjacent positions.
Any number of feeding elements 13 may be provided, depending on the size of the head 1. In the configuration as shown in the drawings by way of example and without limitation, the head 1 has four feeding elements 13.
The feeding elements 13 are evenly arranged along the width of the slot 8.
The distance between two adjacent feeding elements 13 may be selected to ensure the outflow of the same amount of adhesive all along the extension of the slot 8.
Furthermore, the amount of adhesive to be spread by the feeding elements 13 may be unchanged through the various feeding elements 13 or differ from one to the other, for variable adhesive distribution in particular cases.
As shown in the figures, the feeding elements 13, 13' may be equally spaced, each feeding the same amount of adhesive.
The feeding elements 13 comprise a nozzle 14 which is adapted to be fluidically connected to a tank R for the adhesive and has an inlet section 15 and an outlet section 16.
The nozzle 14, as shown in Fig. 7, may be located below the slot 8 and have a substantially cylindrical shape, with the inlet section 15 substantially equal to the outlet section 16.
Other configurations, not shown, may use nozzles 14 with inlet sections 15 different from the outlet sections.
Particularly, heads 1 may be provided which deliver the adhesive within a range of transverse widths of backs D and/or within a range of moving speeds thereof, using nozzles 14 with different inlet 15 and outlet 16 sections.
In a possible variant embodiment, not shown, the feeding means 12 may be associated to sensor means, not shown, which are located in the seat 3, close to the slot 8, and are adapted to detect the block B and its position relative to the slot 8 to turn the feeding means 12 on or off.
The sensor means may be of any type, such as photocells or other proximity sensors.
The controlled feeding means 12 comprise flow adjusting means 17 for adjusting the flow of adhesive to be delivered from each of the outlet sections 16 of the nozzles 14.
The adjusting means 17 interact with each of the nozzles 14 to adjust the amount of adhesive delivered through the slot 8.
Furthermore, these adjusting means 17 may be of either mechanical or hydraulic type and may act upon the outlet sections 16 of the nozzles 14 by the action of electronic control means, not shown.
The action of the adjusting means 17 may be managed by the electronic control means, not shown, according to a fixed sequence selected by an operator upon mounting of the head 1.
Alternatively, this sequence may be changed by the user by interaction with appropriate control and display means, not shown.
Advantageously, the controlled feeding means 12 may include a stabilization chamber 18, as shown in Fig. 5, which is adapted to be connected to the adhesive pumping means P and to be fluidically connected to the nozzles 14.
Furthermore, the controlled feeding means 12 may include a collecting chamber 19, as shown in Fig. 6, which is located upstream from the slot 8 and downstream from the collecting chamber 18 and is adapted to level the adhesive flow.
In a configuration that is not shown in the accompanying figures, the head 1 may have a single collecting chamber 19 designed to be directly connected to the external tank 9, not shown, through the pumping means P.
Nevertheless, the stabilization chamber 18 allows a constant pressure, insensitive to changes in adhesive level in the tank R, to remain in the collecting chamber 19 and hence at the nozzles 14.
The collecting chamber 18 may have an inlet 20 for the adhesive in an appropriate position for connection to the pumping means.
Typically, this inlet 20 is located in the lower part of the stabilization chamber 18 and designed to be removably connected to one or more pipes or the like, not shown, which are connected to the pumping means for the adhesive to be conveyed from the tank to the chamber 18.
As shown in Figs. 7, 8 and 9, the collecting chamber 19 may be of substantially smaller volume than the stabilization chamber 18.
In a particularly advantageous configuration of the invention, this arrangement of the collecting chamber 19 and the stabilization chamber 18 will provide uniform outflow of adhesive all along the width g of the slot 8.
Furthermore, the collecting chamber 19 and the stabilization chamber 18 may have a polygonal shape.
Preferably, the collecting chamber 19 extends in the transverse direction at least along the entire maximum width g of the slot 8.
Advantageously, the adjusting means 17 may include, for each of said nozzles 14, a shutter member (21) which is designed to interact therewith to adjust its inlet section 15.
Furthermore, as shown in Fig. 7, each shutter member 21 comprises a substantially cylindrical stem 22 having a shaped first end 23 inside the stabilization chamber 18 and facing the inlet section 15 of its respective nozzle 14 for at least partially occluding it.
Furthermore, the first end 23 of the stems 22 may have a substantially frustoconical shape and the inlet section 15 of each nozzle 14 may be occluded by introducing such frustoconical end 23 into the section 15.
The stem 22 may have a second end 24 outside the stabilization chamber 18, and associated with actuator means 25 for adjusting the distance of the first end 23 of the stem 22 from the inlet section 15 of each nozzle 14.
These actuator means 25 may impart a mainly translational movement to the stems 22, in a direction substantially parallel to the longitudinal direction L.
Preferably, the stems 22 are designed to move in respective parallel directions.
The stems 22 may be moved between a closed position of the nozzles 14, for preventing adhesive flow into the collecting chamber 19, and a full open position, in which the inlet section 15 of the nozzles 14 is completely unobstructed.
Furthermore, the actuator means 25 may be controlled to move each of the stems 22 to any intermediate position between the full open and closed positions, and in which the inlet section 155 is partially open for partial and controlled flow delivery.
The stems 22 may slide in appropriate bushings 26 connected to the frame 1 and communicating with the stabilization chamber 18.
These bushings 26 may include seals 27 or similar sealing members 28, for preventing adhesive leakage as the stem 22 is moved.
Furthermore, the actuator means 25 may include a bracket 29 integral with the second ends 24 of the stems 22 and associated with motor means 30 for synchronized movement of the stems 22.
As shown in Fig. 3, the bracket 29 may have a comb-like configuration, with respective portions 29', 29", 29''', 29^IV removably connected to the stems 22 by interlocking means 31.
This anchor bracket 29 is also connected to a hydraulic device 32 which is adapted to transfer the motion generated by the motor means 30 in a longitudinal direction substantially parallel to the direction of movement of the stem 22.
The bracket 29 may have a substantially flat shape and be elastically deformable, so that a thrust higher than the minimum thrust required for shutting off the nozzles 14 is imparted to the stems 22, for the nozzles to be perfectly closed.
Advantageously, the main frame 1 may have inclined plan means (33) located at said seat 3 for at least partially collecting the overflown adhesive and conveying it into an auxiliary container 34.
According to the configuration of the invention as shown in the figures, the inclined plan means 33 may include a pair of channels 35, 35' extending in a substantially transverse direction and located below the slot 8.
Furthermore, the channels 35, 35' may have a first end edge 36, 36' at the seat 3 and a second end edge 37, 37' at the transverse end 38 of the main frame 2.
The auxiliary container 34 for collecting the overflown adhesive may be placed at the second end edge 37, 37' of the channels 35, 35'.
In operation, when no block B of sheet elements F is present, the shutter member 21 is in the closed position, with its first end 23 in contact with the inlet section 15 of the nozzle 14 to prevent adhesive from flowing out of the slot 8.
In this operating state, the pumping means convey the adhesive into the stabilization chamber 18 at a predetermined pressure.
Upon detection of a block B of sheet elements F proximate to the slot 8, the motor means 30 are operated to translate the shutter members 21 from the closed position to the open position, to at least partially open the nozzles 14 and allow controlled adhesive delivery.
The pressure of the adhesive in the stabilization chamber 18 will allow the latter to fill the collecting chamber 19 and flow out of the slot 8 onto the back D of the block B.
The excess adhesive that has flown out of the slot 8 and has not been transferred to the block B is collected by the inclined plan means 33 and stored in the auxiliary container 34.
Once the block B has completed its passage over the slot 8, the shutter members 21 will be translated back to the closed position to prevent the adhesive from being transferred into the collecting chamber 19.
In this operating state, the collecting chamber 19 may still contain adhesive, but the latter cannot flow out of the slot 8 because there is not enough pressure in the chamber 19 for delivery thereof.
This additional aspect of the invention is particularly advantageous because the chamber 19 is ready for adhesive delivery in the next duty cycle.
In a particularly advantageous configuration of the invention, the small size of the collecting chamber 19 will limit adhesive waste when the head 1 is expected to be inoperative.
In that case, the slot 8 and a portion of the collection chamber 19 may be easily filled with materials that protect the adhesive in the collecting chamber 19 from permanent contact with air.
Furthermore, if adhesive contacting areas are to be cleaned with special cleaning products, the small size of the collecting chamber 19 allows such step to be carried out in a short time and using a small amount of such products.
The above disclosure clearly shows that the adhesive delivering head and the machine incorporating such head fulfill the intended objects and particularly meet the requirement of uniformly spreading a predetermined amount of adhesive on the back of a block of sheet elements to be bound.
The head and machine of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the appended claims. All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the invention.
While the head has been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Claims

An adhesive delivering head applicable to a binding machine for binding blocks (B) of sheet elements (F) having a binding back (D) and a predetermined thickness (s), the head comprising:
- a main frame (2) with a longitudinal seat (3) having a predetermined width (w) for guiding a block (B) of sheet elements (F) to be bound in correspondence of the back (D);

- a substantially transverse slot (8) having a predetermined maximum width (g) formed in a portion (9) of said seat (3) for the local distribution of a fluid or semi-fluid adhesive on the back (D) of the block to be bound;

- means (12) for the controlled feeding of a predetermined amount of adhesive into said slot (8);
wherein said controlled feeding means (12) comprise a plurality of feeding elements (13) evenly distributed along the width (g) of said slot (8) for spreading the adhesive into said distribution portion (9) in a substantially uniform manner and means (17) for adjusting the flow rate of the adhesive;
wherein each of said feeding elements (13) comprises a nozzle (14) fluidically connectable with a tank (R) for the adhesive and having an inlet section (15) and an outlet section (16);
characterized in that said adjusting means (17) comprise, for each of said nozzles (14), a shutter member (21) designed to interact with a respective nozzle (14) for adjusting the inlet section (15) thereof.
Head as claimed in claim 1, characterized in that said feeding means (12) further comprise a collection chamber (19) upstream of said slot (8) for uniforming the adhesive flow.
Head as claimed in claim 1, characterized in that said controlled feeding means (12) comprise a stabilization chamber (18) upstream of said collection chamber (19) and connectable to pumping means (P) of the adhesive and fluidically connected to said nozzles (14).
Head as claimed in claim 3, characterized in that each of said shutter members (21) comprises a substantially cylindrical stem (22) having a shaped first end (23) inside said stabilization chamber (18) and facing said inlet section (15) of said nozzle (14) for at least partially occluding it.
Head as claimed in claim 4, characterized in that said stem (22) comprises a second end (24) placed externally to said stabilization chamber (18).
Head as claimed in claim 5, characterized in that said second end (24) of said stem (22) is associated to actuator means (25) for adjusting the distance of said first end (23) of said stem (22) from the inlet section (15) of each nozzle (14).
Head as claimed in claim 6, characterized in that said actuator means (25) comprise a bracket (29) solidal with the second ends (23) of said stems (22) and associated to motor means (30) for promoting a synchronized movement of said stems (22).
Head as claimed in any of preceding claims, characterized in that said main frame (2) has inclined plan means (33) located at said seat (3) for collecting at least partially the overflown adhesive and conveying it into an auxiliary container (34).
A binding machine for binding blocks (B) of sheet elements (F) comprising an adhesive delivering head (1) according to one or more of preceding claims.