US3531358A - Apparatus for the binding of stacked sheets - Google Patents

Description

APPARATUS FOR THE BINDING 0F STACKE D SHEETS Filed April 25, 1967 Sept. 29, 1970 osT ETAL 5 Sheets-Sheet l THERMALLY l OWABLE ADHESIVE Atfomc y APPARATUS FOR THE BINDING OF STACKED SHEETS Filed April 25, 1967 Sept. 29, 1970 H. ROST ETAL 3 Sheets-Sheet 2 INVENTOR.

Sept. 29, 1970 H. ROST ETAL 3,531,358

APPARATUS FOR THE BINDING OF STACKED SHEETS- Filed April 25, 1967 s Shects-5heei 5 BY {Kari Attorney INVENTOR.

United States Patent Int. (:1. B29c 24/00 U.S. Cl. 156-475 12 Claims ABSTRACT OF THE DISCLOSURE Apparatus for the adhesive binding of stacks of sheets or leaves whereby the stack is jogged with an edge against a supporting plate and the plate is heated and withdrawn from the stack which is held in a clamp while a foil of thermally fiowable solid adhesive is placed between the hot plate and the juxtaposed edge of the stack in the form of a slip fold, the latter being then bonded to the edge and around the cover and backing sheets of the stack between split sections of the heated plate. The slip fold comprises a reinforcing web of paper, gauze cellulose hydrate as a backing layer coated by the thermally sensitive adhesive or a reinforcing web embedded therein.

The invention relates to an apparatus for the threadless binding of piles of sheets in which a solid adhesive free from solvent (meltable adhesive) is used which is reduced to a fluid state and rendered adhesive by the action of heat.

Piles of sheets are generally treated with a liquid adhesive and then allowed to set. The piles of sheets thus treated are, however, not ready for use until the adhesive has set, depending upon the time required by the solvent to evaporate.

In order substantially to reduce the setting time, it is known to use so-called meltable adhesives (hot melt) which form a solid mass since they contain no liquid solvent of any kind. This mass is reduced to a fluid state and becomes adhesive when it is heated.

It is known to reduce meltable adhesives of this kind to a fluid state by heating them in a container, and to 4 apply the hot adhesive to the workpiece by mechanical means, for example by dipping or immersion plates. Apart from the substantial amount of energy required, particular difficulties are caused by the long heating-up periods having to be allowed for before the work is started, the constant presence of air in the zone of adhesive application involving the danger of oxidation, and the loss of time due to starting and stopping of the machine with resultant variation of the conditions under which the meltable adhesive is applied. Particular disadvantages arise from the fact that large quantities of the meltable adhesive have to be heated up, whereas only small portions thereof can be treated at a time.

It is the object of the invention to avoid these diffi culties and to develop a cheap and, at the same time, time-saving binding method in which meltable adhesives are used.

In accordance with the invention, the solid adhesive applied in the form of a foil to the back of the pile of sheets or leaves is heated subsequently to its application.

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This affords the advantage that only a small portion of the adhesive has to be heated at a time, so that a substantial amount of energy and time is saved, and the meltable adhesive is not subjected to excessive thermal stresses.

Within the framework of the invention it has been found to be advantageous for a support coated with the solid adhesive to be applied to the back of the pile of sheets or leaves and then to be heated. In accordance with the invention, a slip-fold or the like consisting preferably of a strip of paper, gauze, cellulose hydrate or equivalent material may be used. In accordance with the invention, the layer of adhesive to be applied to the back of the pile of sheets or leaves may also be provided with at least one layer of gauze, fiber, or a fleecy material.

The apparatus according to the invention comprises a clamping device, by which the pile of sheets or leaves is held in position, and, extending at right angles thereto, adjacent thereto or at a distance therefrom, a jogging face contacted by the sheet edges to be glued together.

In accordance with the invention, the jogging surface forms part of a directly or indirectly heated hot plate disposed at an adjustable distance from the clamping device to enable a support in the form of a strip coated with meltable adhesive to be introduced.

The apparatus affords the advantage that the pile of sheets may be jogged directly on the hot plate and then clamped in position so that the back of the pile of sheets assumes an exactly determined position relative to the hot plate. The support is applied to the spine of the pile of leaves under a suflicient pressure when the hot plate is moved a slight distance away from the spine of the pile in order to enable the support coated with the meltable adhesive to be introduced into the gap thus formed, and when the hot plate is subsequently returned to its original position. The hot plate has to be preheated for a predetermined period previously and then has to remain constantly heated so that the adhesive reduced by the hot plate to the fluid state glues the edges of the sheets securely together to form a secure bond within a minimum period of time. The single heating-up of the hot plate requires much less energy and time than the conventional heating of the meltable adhesive in a bath.

In accordance with the invention furthermore, the hot plate may be of a bipartite or multipartite construction, each component part being adapted to move at right angles to the jogging surface. It is advantageous for at least the larger section of a bipartite hot plate to be adapted to move parallel as well as at right angles to the jogging surface. It has also been found to be advantageous for the abutting end of the bipartite hot plate to be disposed in substantially the same plane as the contact surface of one of the clamping elements of the clamping device.

The bipartite or multipartite construction of the hot plate affords the advantage that a slip fold may serve as a support for the meltable adhesive to glue the back of the pile of sheets; in addition, its peripheral zones are folded around the back of the pile of sheets and glued to the cover and base sheets of the pile in the manner usual in slip-folding operations. The multipartite construction of the hot plate enables the abutting ends thereof to be used not only for folding back to the peripheral zones of the slip fold, but also for pressing or rubbing it against the cover and base sheets of the pile. The fact that these abutting ends of the hot plate are also adapted to be heated results not only in the mechanical phase of the movement hereinbefore described, but also in a more expeditious liquefaction of the meltable adhesive in the folded-over state.

In accordance with the invention, furthermore, the hot plates are advantageously mounted on a vertically ad- 3 justable trestle and connected to a cam or eccentric drive. It has been found particularly advantageous to provide a control shaft, preferably of a manually operable construction, secured to the driving means by which the sections of the hot plate are lifted and moved apart so that the movements proceed in the correct order of succession in the manner of a follower or sequential control, as the control shaft is turned.

In one construction according to the invention, a feed bar needled with spikes or the like for advancing the support of the meltable adhesive is provided which moves substantially in the plane of the jogging surface. In accordance with the invention, the support has previously been cut to the correct measurement, so that there is merely the problem of moving the support to the correct position below the back of the pile of sheets without damaging the adhesive coating and without the succession of movements being disturbed by the layer of adhesive. It will be understood that it is within the scope of the invention to feed the support directly from the roll, which is then cut to the correct length in the zone of the binding machine.

Details of the invention are diagrammatically illustrated by way of example in the accompanying drawing in which:

FIG. 1 is a longitudinal sectional elevation of a threadless-binding machine; and

FIGS. 2 to 9 show corresponding longitudinal sections through the threadless-binding machine in various phases of movement.

The construction according to the invention illustrated in FIG. 1 comprises a manually operated machine for the threadless binding of piles of sheets or leaves 1, of whose edges 2 to be glued are to be contacted with a support 3 which is coated with a layer of meltable adhesive. In the construction illustrated by way of example in the drawing, it is assumed that the support 3 has previously been cut to the correct size externally of the threadless-binding machine. The support 3 is moved to the zone of the sheet edges 2 to be glued by a feed bar 4 needled with spikes 5. The preferred support used for the glueing operation is a slip fold which is effective to bring about an adhesive bond under the edges of the sheets, to glue the back of the pile of sheets, and, finally, to glue the cover and base sheets of the pile in the peripheral zone.

In the construction illustrated by way of example in FIG. 1, the pile of sheets 1 is clamped in position by a bipartite clamp 6 provided at a distance from the jogging surface 8. The jogging surface 8 constitutes simultaneously a major part of a hot plate 9 which consists preferably of two hotplate sections 11 and 12. The vertical junction between abutting contact edges 10', 10" (FIGS. 5 and 6) of the two hotplate sections 11, 12 is disposed substantially in the same plane as the contact surface 7 of one of the clamping elements 6. The hotplate 9 may be heated directly. In the illustrated embodiment, the heating elemerits (not shown) are disposed in a table top 20, so that the hotplate 9 is heated indirectly, during which process the two plates 9 and should contact each other directly.

In FIG. 1, the hotplate 9 is mounted on a trestle or brace 14 which is moved by guide rods 15 in bearings 13 at right angles to the jogging surface 8, so that the jogging surface 8 may be moved toward and away from the sheet edges 2 to be glued. The trestle 14 is driven by an eccentric 16 which may be operated by a crank or the like.

The individual operations required to produce the adhesive bond in the illustrated embodiment are shown in FIGS. 2 to 8.

FIG. 1 shows the apparatus according to the invention with the hotplate 9 in its normal position, the clamping device 6 being released to enable the pile of sheets 1 to be leveled on the jogging surface 8 of that plate. The clamping device is then operated, and the pile of sheets 1 is thus clamped in position so that the sheet edges 2 to be glued come to rest exactly on the jogging surface 8. The hotplate 9 is then heated for about 20 minutes, the heating being preferably continued throughout the operating cycle. In the initial phase illustrated in FIG. 1, the meltable adhesive on the support 3 is still in the solid state, being held separated from the hotplate assembly 9, 20.

It is now necessary for the support 3 to be moved into the gap between the pile of sheets 1 and the hotplate 9. For this reason, the eccentric or cam 16 (FIG. 2) is turned until the hotplate 9 together with the trestle 14 descends. The support 3 is then introduced by feed bar 4 into the gap formed between the sheet edges 2 and the jogging face 8; conventional markings or other auxiliary means may be used for this purpose in order to adjust the correct position of the support 3. During operation, the movement of the feed bar 4 is advantageously geared to the movement of the trestle 14. This may advantageously be achieved, for example, by means of a crank drive starting from the shaft of the eccentric 16. As best seen in FIG. 3, the width of the support 3 exceeds the width of the pile of sheets 1. As previously mentioned, a slip fold is used by which. not only the back of the pile of sheets but also the peripheral zones of the cover and base sheets are glued. In the subsequent operations, the feed bar 4 may remain in the illustrated position since it does not interfere with the process.

Whereas FIG. 3 shows the slip fold-type support 3 spaced from the underside of the pile of sheets 1, FIG. 4 shows the eccentric as it is returned to its original position, so that the hotplate 9 together with the support 3 resting thereon may be pressed against the sheet edges 2 of the pile 1 to be glued. The plate 9 may then be heated if this has not been carried out previously. The solid meltable adhesive is thus reduced to the thermoplastic state, the flowing adhesive being distributed between the sheet edges so as to create the necessary conditions for a perfect adhesive bond.

FIGS. 5 to 8 illustrate the completion of the adhesive bond by the use of the slip fold 3, and the folding operation. In FIG. 5, the larger section 12 of the hotplate is moved to the right until its contact edge 10" has reached a position substantially in the plane of the right-hand face of the pile of sheets 1, a recess being thus formed below the sheet edges 2 to be glued.

A lifting cam 19, larger than eccentric 16, on a control shaft 17 is then rotated to raise the trestle 14 and the hot plate 9 to an extent sutficient to ensure that the exposed edges of the slip fold 3 are bent back as illustrated in FIG. 6 and can be pressed against the cover and base sheets of the pile of sheets 1 as illustrated in FIG. 7. The edges 18 of the support or slip fold 3 are then bent up pressed against the stack 1 and heated by the contact edges 10, 10" of the hot- plate sections 11, 12. It will be noted that the adhesive bond and the folding proceed in one operation. When the position illustrated in FIG. 7 has been maintained for a predetermined period of time until the setting process is complete, the hot plate 9 and the trestle 14 are lowered to their initial position and the hotplate sections 11, 12 are simultaneously re-joined. The clamping device 6 can then be released and the glued and folded pile of sheets 1 can be Withdrawn without the risk of the adhesive bond being disturbed, since the meltable adhesive sets within a short time. Even when the heating elements are dispersed in the table top 20, the meltable adhesive is adequately heated in the zone of the contact edges 10, 10" owing to the increased heating area which is effective when the hot- plate sections 11, 12 have been moved apart.

It will be understood that it is advantageous for the control shaft 17 to be connected to the driving means required for lifting and moving the hot- plate sections 11, 12 apart. The compressive motion illustrated in FIG. 7 can be carried out by the same apparatus so that, as the control shaft 17 rotates through a predetermined angle, all the necessary operations may proceed in the correct order of succession without the occurrence of errors. The eccentrics 16 and 19 are advantageously secured to different shafts.

FIG. 9 shows by way of example the manner in which the control shaft 17 can be used both for pulling the hotplate sections 11, 12 apart and for lifting the work table 14. Connected to a crank pin 21 by a link 22 is a rocker arm 23 which drives the hot-plate section 12 by means of a guide lever 24. The control shaft 17 has thus only to be turned through a certain angle to carry out the necessary operational steps in the correct order of succession.

A piece of film of meltable adhesive corresponding to the measurement of the spine of the book is cut off, placed on the jogged, cut stack, and pressed slightly against it with simultaneous heating. The adhesive layer melts at a temperature upward of 80", more specifically a temperature of 100, to such an extent as to form a satisfactory bond with the edges of the individual sheets. The bond sets upon cooling.

In the simplest case, it is sufiicient to use a smoothing iron for this operation. Inexpensive tools may be used even for series production. The film of meltable adhesive may be used in the form of an unsupported foil, or it may be applied to a backing according to the requirements of the processing plant.

The unsupported material will be preferred when the stack bonded with adhesive is to be cased or inserted as a pamphlet, since the cover can then also be glued in position by slight re-heating.

For purposes of this kind, even more durable layers may be obtained by embedding a gauze or a fleecy material in the meltable adhesive, e.g. when the stack is to be processed as a book. When the stack is to be folded, a meltable adhesive supported by a binding or folding material, such as paper, linen or the like, is advantageously used, so that the binding and folding steps are carried out in one operation.

The thermally flowable adhesive referred to above is conventional in the art of bookbinding; see, for example, US. Pat. Nos. 1,858,685 (Rubber Isomers), 2,579,488

(Polyvinyl Chloride) or 3,223,436 (Polyethylene).

Finally, a support consisting of a foil of cellulose hydrate may be used which, during the folding operation, produces a high-gloss spine which may, however, be removed if required, after having been moistened with water, e.g. when the film of meltable adhesive is still to be used for glueing the book into a cover. The films of supported or unsupported meltable adhesive are produced by casting from the melt, e.g. by means of a heated spreading tool in a conventional coating machine in which the drying channel can be utilized for cooling but may also be dispensed with.

It will be understood that the embodiment illustrated by way of example in the drawings may be modified in many ways, as by providing a fully automatic threadlessbinding machine of a similar construction.

We claim:

1. An apparatus for binding a stack of sheets, comprising:

jogging means including a plate with a generally flat surface adapted to align a stack of sheets, extending perpendicularly to said surface, along at least one edge of the stack;

clamping means engageable with said stack for retaining said sheets in an aligned condition and supporting said stack independently of said plate;

heating means for said plate;

reversible shifting means for relatively displacing said clamping means and said plate to form a gap between said surface and said edge of the stack engaged by said clamping means;

and mechanism for inserting into said gap a strip of a thermally flowable adhesive adapted to be bonded to said sheets along said edge at the temperature of said plate upon subsequent relative reverse displacement of said plate and said clamping means.

2. The apparatus defined in claim 1 wherein said surface is horizontal, said shifting means comprising a ver tically reciprocable brace carrying said plate and an eccentric drive engageable with said brace for raising and lowering said plate relatively to said clamping means.

3. The apparatus defined in claim 1 wherein said plate is split into two normally contiguous sections separable, upon formation of said gap by the operation of said shifting means, to define between them a recess registering with said edge, said recess having boundaries flanking said stack for pressing bentover marginal portions of said strip against the outer sheets of said stack upon reverse opera tion of said shifting means to introduce part of said stack into said recess.

4. The apparatus defined in claim 3 wherein said shifting means comprises first camming means for defining a. normal relative position of said plate and said clamping means in which said stack bears upon said surface with said sections contacting each other, prior to formation of said gap, said shifting means further comprising second camming means for relatively displacing said plate and said clamping means toward each other beyond said normal position with said sections spaced apart to introduce said part of said stack into said recess.

5. The apparatus defined in claim 4 wherein one of said sections is stationary and forms with a contact edge of the other section in their contiguous position a junction substantially in the plane of one face of said stack, further comprising separating means operable in timed relationship with said shifting means for moving said other section into a spaced-apart position in which said contact edge lies substantially in the plane of the other face of said stack.

6. The apparatus defined in claim 5 wherein said surface is horizontal, further comprising a table supporting said sections while being vertically movable by said shifting means, said other of said sections being slidable on said table.

7. The apparatus defined in claim 1, further comprising a table carrying said plate, said heating means being provided in said table.

8. The apparatus defined in claim 1 wherein said mechanism includes a feed bar provided with a plurality of spikes and shiftable in a plane parallel to said surface for advancing the strip.

9. An apparatus for binding a stack of sheets, comprising:

a plate split into two normally contiguous sections with a continuous surface adapted to align a stack of sheets, extending perpendicularly to said surface, along at least one edge of the stack, said sections being separable to define between them a recess registering with said edge;

clamping means engageable with said stack for retaining said sheets in an aligned condition and supporting said stack independently of said plate, said clamping means being movable relatively to said plate to form between said edge and said surface a gap for the insertion of a strip of a thermally flowable adhesive in the contiguous position of said sections;

and heating means for said plates to bond said strip onto said edge and onto the outer sheets of said stack upon introduction of part of said stack together with said strip into the recess formed by the separated sections.

10. An apparatus for binding a stack of sheets, com prising:

jogging means including a plate with a generally fiat surface adapted to align a stack of sheets, extending perpendicularly to said surface, along at least one edge of the stack;

clamping means engageable with said stack for retain- 7 ing said sheets in an aligned condition and supporting said stack independently of said plate, said clamping means being movable relatively to said plate to form a gap between said edge and said surface; heating means for said plate;

and mechanism for inserting into said gap a strip of a thermally flowable adhesive adapted to be bonded to said sheets along said edge at the temperature of said plate, said mechanism including a feed bar provided with spikes and shiftable in a plane parallel to said surface for advancing said strip.

11. An apparatus for binding a stack of sheets, comprising:

a table provided with heating means;

a plate disposed on said table in heat-transfer relationship therewith, said plate having a generally flat surface;

jogging means including said plate for aligning a stack of sheets, extending perpendicularly to said surface, along at least one edge of said plate;

clamping means engageable with said stack for retaining said sheets in an aligned condition and support- 8. ing said stack independently of said plate, said clamping means being movable relatively to said plate to form a gap between said edge and said surface;

and mechanism for inserting into said gap a strip of a thermally flowable adhesive adapted to be bonded to said sheets along said edge at the temperature of said plate.

12. The apparatus defined in claim 11 wherein said jogging means includes means for shifting said plate perpendicularly to the jogging surface thereof.

References Cited UNITED STATES PATENTS 3,223,436 12/1965 Becker 281-21 XR 2,968,336 1/1961 Martin et a1. 1,858,685 5/1932 Semon 28121 2,579,488 12/1951 Freeman 28121 PHlLIP DIER, Primary Examiner US. Cl. X.R.

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