Vibratory book binding method

Abstract

Adhesive joinder of the body of a book to a case is obtained by compressing the assembled body and case with book binding clamps to bring adhesive joinder areas into contact. In addition to the compression of the body and case, vibratory blows are applied to the assemblage to enhance the adhesive action of the joinder areas. Heat may be applied to dry or cure the adhesive.

Description

BACKGROUND OF THE INVENTION

1. field of the Invention

The present invention relates to book binding methods and apparatus suitable for that step in the book binding process commonly termed building in.

2. Description of the Prior Art

In the book binding process, a body of leaves is joined to a case comprised of the covers and spine. A glue or paste is applied to selected portions of the body or case. The body is then inserted in the case and the assemblage compressed as by clamping means to bring the bonding surfaces into contact to effect the joinder and form the hinge area of the book.

There has heretofore arisen problems in conventional book binding case, and securing a bond of adequate strength between the body and the case. This is particularly true of the bonds in the indented hinge areas adjacent the spine of the book which allow the covers to be opened and lie flat and the pages to be turned.

Simple compressive forces appear inadequate to provide the degree of adhesion necessary. Further, in some instances, there is a tendency for the book elements to spring apart once the compressive forces are released, due to the resiliency of the materials and because the glue has not dried. The hinge areas are especially subject to this failing because of the flexural properties which must be provided to this area to permit opening and closing of the book. Heat may be applied to the hinge areas to hasten drying or curing of the glue. For this purpose, resistance heaters and the like have been placed in the clamping means. However, because of the numerous layers, the air spaces between them, and the poor heat conduction properties of the book materials, heating of the glue may be difficult to obtain without raising the temperature of the clamping means to the point where scorching of the exterior of the case becomes likely.

SUMMARY OF THE PRESENT INVENTION

The gist of the present invention is to improve the strength of the internal adhesive bonds in books by providing an improved book binding method which introduces vibratory compressive blows in addition to the relatively constant compressive clamping forces. In a modification of the method of the present invention, heat may be applied during the vibratory action to dry or cure the adhesive while the book is under compression, thereby to prevent any separation of the book portions upon termination of the vibratory blows and compressive forces. For this purpose a bonding agent heatable upon exposure to a selected form of indirectly applied energy may be employed.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a fragmentary, cross sectional view of a book of conventional construction which may be bound by the process of the present invention.

FIG. 2 is a cross sectional view of a building in machine showing the method and apparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a conventionally bound book 10. Book 10 is comprised of two main components -- body 12 and case 14.

Body 12 is formed of a plurality of leaves 16 commonly grouped into signatures, sewn together along one edge. Body 12 includes end papers 18 on either side thereof and crash or super 20 extending across the sewn edge of the body outside the end papers. The case 14 for hard cover books includes front and back covers 22 and 24 formed of boards covered with buckram 25 or other flexible material which also forms spine 26. In soft cover books, a single piece of folded paperboard may form the case.

In book 10, when bound, end papers 18 and super 20 are glued to the inside of covers 22 and 24 with glue 27. The adjacent portions of the spine are creased so as to form hinge areas 29.

In the book binding process and apparatus, the elements of the book are moved in seriatum down a casing in line. Typically, joint adhesive 27 is applied to the hinge areas of body 12 while a casing in paste is applied to end papers 18 and adjacent portions of super 20. The body is then placed in case 14 so that the glued areas are properly located.

The final operation is a pressing of the book between mechanical clamps to bring the end papers, super, and covers into secure contact, to form the crease at the hinge area, and compress the portions of the book at the hinge area to secure adhesive joinder in this area.

The machine used to perform these operations is commonly termed a building in machine. As shown in FIG. 2, the machine includes opposed force applying means 30 suitable for compressive abutment with front and back covers 22 and 24 of book 10. Means 30 are variously known as pockets, platens, or clamps. For exemplary purposes, clamps 30 may be brought into abutment with covers 22 and 24 by means of cams and followers. As book 10 and the associated clamps 30 move along the casing in line, followers 32 are brought into contact with the rises of cams 34 which force clamps 30 against covers 22 and 24 and apply a compressive force. Spring 31 returns clamps 30 to the open position.

The building in machine also includes means 36 for compressing and forming the hinge areas of the book. Means 36 are variously known as shoes, creasers, hinge irons, joint irons, nippers, or joint formers. Similar to clamps 30, creasers 36 are brought into abutment with hinge areas 29 of book 10 by means of followers 38 coupled to the creasers which engage the rises on cams 40 and returned to the open position by a spring return, not shown.

It will be appreciated that the building in machine typically includes a plurality of stations in the casing in line at which the specific operations or steps of the book binding processes are performed. The stations may be arranged in line, or in a circular or other suitable configuration. The clamps and/or creasers may move with the book between stations or may remain at the stations as the book is advanced down the line.

In accordance with the present invention, means are provided to apply vibratory blows to book 10 in addition to the constant compressive forces applied by clamps 30 and creasers 36 at one or more of the stations of the building in machine. To this end, vibratory driver means 42 are interposed between the clamps 30 and the cam 34-follower 32 structures. Vibratory driver means 44 are interposed between creasers 36 and cam 40-follower 38 structures. Such a vibratory means may include wire coil 46 coupled to an alternating current power supply 48. A solenoid core or slug 50 is mounted within the coil 46 for axial movement responsive to alternating current energization of the coil. Solenoid core 50 may be biased by a spring, not shown.

The repetition rate of the vibratory blows produced by the vibratory driver means is a function of the frequency of the alternating current power supply, typically twice the alternating current frequency. The repetition rate of the vibratory blows may be altered by altering the frequency of the alternating current power supply. From a 60 cycle AC power supply, 120 vibratory blows per second are obtained. Repetition rates of this magnitude have generally been found suitable for use in the practice of the method of the present invention.

While a wide range of vibratory frequencies can be used, the present invention does not contemplate the use of frequencies in the ultrasonic range, for example, 15,000 Hz and above, for several reasons. The present invention is directed to a wet bonding system and to mechanical treatment of adhesives in the fluid state by vibratory blows. Ultrasonic treatment tends to be unsuited for the liquid adhesives and resilient materials found in book binding applications. Further, ultrasonic vibrations of a sufficient amplitude to cause any sort of internal mechanical treatment in the book would in all likelihood cause the damaging heating of the exterior of the cover commonly termed "ultrasonic burn".

As shown in FIG. 2, solenoid cores 50 of vibratory driving means 42 are coupled to clamps 30 on either side of book 10 while coils 46 are pinned to followers 32. Similarly, solenoid cores 50 of vibratory means 44 are coupled to creasers 36 on either side of hinge areas 29 while the coils are connected to follower 38. The coupling of vibratory driver means to the pressure applying means may be direct connection, as shown in FIG. 2, in connection with clamps 30, or may be a loose coupling as shown in connection with creasers 36, in which plate 45, abuts the back of creasers 36.

In performing the method of the present invention, parts of the books are moved, in seriatum, along a casing in line. At a predetermined point or points in the line, a glue, such as book binder's or casing in paste, is applied to the preselected areas of the body, for example, to the super and to the exterior of the end papers and joint adhesive 27 is applied to hinge areas 29 of body 12. Body 12 is inserted in case 14 and the assemblage placed in binding clamps 30. The movement of book 10 and binding clamps 30 along the casing in line causes followers 32 to contact the rises on cams 34 extending clamps 30 and compressing book 10 to bring super 20 and end papers 18 into firm contact with covers 22 and 24. In a similar manner, followers 38 contact the rises on cams 40 moving creasers 36 into abutment with hinges areas 29 to form the creases at the hinge areas and to press the hinge area portions of the book together.

At the same time, vibratory driving means 42 and 44 may be actuated, either by the movement of clamps 30 and creasers 36 or independently thereof, to apply vibratory blows to book 10, to improve the joinder of the body to the case. The primary improvement is believed to result from better wetting by the liquid glues and adhesives of the various solid surfaces being bonded, as well as an actual forcing action tending to drive the glues more deeply into the surface of the paper, fabric or other fibrous or porous materials comprising the book at the areas being joined. The vibrations also remove air trapped in the adhesives and glues further enhancing the joinder.

The vibratory action may be concluded when followers 32 and 38 fall off the rises of cams 34 and 40, retracting clamps 30 and creasers 36.

In the vibratory book binding method of the present invention, it has been found desirable to decrease the level of the compressive force exerted on the assembled book from that ordinarily used so as to permit small movements of clamps 30 and creasers 36 as they exert the greater and lesser forces which characterize the vibratory action. The magnitude of the vibratory action and the compressive force exerted by clamps 30 and creasers 32 may thus be correlated to produce the desired results. However, it has ben found undesirable to permit sufficient motion as to allow the clamps to lift from the surface of the book as the book may slip from the proper position in the building in machine. Cycle times for the vibratory action may be adjusted according to the viscosity of the glue, the porosity of the paper, and fabrics, and similar criteria. In a multiple station machine, cycle times may typically run 0.8 sec. of vibratory action at each station.

The improvements obtained by the practice of the present invention may be further enhanced by applying heat to the book elements to accelerate the drying or curing of the glue and retain the superior joinder obtained by the vibratory blows. This consideration is particularly important at the hinge area of the book because of its critical importance to the book and the stresses to which it is subjected.

While such heat may be applied by resistance heaters or the like located in the creasers or in portions of the clamps, the present invention contemplates the use of a bonding agent heatable upon exposure to a selected form of indirectly applied energy, for example, alternating magnetic or electric fields. For this purpose, the adhesive used in the book binding process may comprise an adhesively thermoplastic or thermosetting bonding agent carrier having dispersed therein particulate material susceptible to heating upon exposure to the indirectly applied energy. The material is incorporated in the bonding agent carrier in quantities sufficient to produce the desired heating action. This is typically 10 to 50% by weight with respect to the bonding agent. To provide a bonding agent heatable by an alternating magnetic field, the susceptor material may preferably comprise fine particles of iron oxide, such as gamma Fe.sub.2 O.sub.3 or Fe.sub.3 O.sub.4. To provide a bonding agent heatable responsive to an alternating electric field, polyvinyl chloride may be utilized as the susceptor material. In some instances it may be possible to select a dielectrically heatable substance which itself may act as the bonding agent.

The bonding agent is applied to the selected areas of body 12 or case 14. The body is inserted in case 14 and the assembled book placed in the building in machine. In the instance in which the susceptor is inductively heatable, an alternating magnetic field may be established by coils 52, shown in cross-section in FIG. 2, connected in series with high frequency power supply 54. The series connection is completed by a jumper, not shown. The coils may be located in clamping means 30 or creasers 36, also as shown in FIG. 2. Coils 52 may be cooled by coolant circulated in passages 56 to prevent scorching or degradation of buckram 25 of covers 22 and 24.

Upon the energization of coils 52, a magnetic field is created which permeates assembled book 10, inductively heating the susceptor material in the bonding agent, driving off solvents and causing the bonding agent to dry or curing a heat activated resin bonding agent. The magnetic field created by coils 52 may typically range from 0.5 to 6 megahertz although frequencies of up to 30 megahertz are conveniently obtainable with conventional helical coils. When the desired degree of heating has been obtained, coils 52 are deenergized and book 10 removed from the building in machine.

The bonding agent carrier may comprise a hot melt adhesive, in which case the indirectly applied energy may be applied at the same time as the vibratory blows to render the bonding agent liquid. The heating may be terminated either before or after the vibratory blows.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

Claims

We claim:

1. An improved method of joining a body of leaves within an embracing case having front and back covers to form a bound book of conventional construction, said method comprising the steps of:

applying a liquifiable adhesive to selected areas of at least one of the body or case;

placing the body in the case with the covers on either side of the body;

compressing the assembled body and case to bring the adhesive areas of one book element into contact with the other book element;

causing the adhesive to assume a liquid state;

applying vibratory compressive blows to the compressed assembled body, case the liquid adhesive at less than ultrasonic frequencies and at a magnitude sufficient to mechanically enhance the adhesive action in the joinder area; and

terminating the compression of the body and case and the application of the vibratory blows.

2. The improved method of claim 1 wherein the joinder of the body and case occurs, in part, along abutting areas of the front and back covers and the book body, and wherein the steps of the method are further defined as comprising, applying adhesive to the abutting areas of the body or case, compressing the abutting areas, applying vibratory blows to the abutting areas, and terminating the compression and vibratory blows.

3. The improved method of claim 1 wherein the joinder of the body and case occurs in part at hinge areas of the book and wherein the steps of the method are further defined as comprising, applying adhesive to the hinge areas of the body or case, compressing the hinge areas, applying vibratory blows to the hinge areas of the book, and terminating the compression and vibratory blows.

4. The improved method of claim 2 wherein the joinder of the body and case also occurs, in part, at hinge areas of the book and wherein the steps of the method are further defined as comprising, applying adhesive to the hinge areas of the body or case, compressing the hinge areas, applying vibratory blows to the hinge areas of the book, and terminating the compression and vibratory blows.

5. The improved method of claim 1 wherein the amount of compression applied to the assembled body and case is correlated to the magnitude of the vibratory blows so as to permit the latter to vary the forces to be applied to the assemblage.

6. The improved method of claim 1 wherein the compression of the assembled body and case is provided by clamping means and the magnitude of the vibratory blows is correlated to the amount of compression and the resiliency of the book materials to retain the clamping means in contact with the case.

7. The improved method of claim 1 wherein the vibratory blows are applied at a repetition rate of 120 blows per second.

8. The improved method of claim 1 wherein the adhesive is thermally responsive, said method including the step of applying heat to the assemblage at least during the application of the vibratory blows.

9. The improved method of claim 3 wherein the adhesive is thermally responsive, said method including the step of applying heat to the assemblage at least during the application of the vibratory blows.

10. The improved method of claim 1 wherein the adhesive is thermally responsive to a selected form of indirectly applied energy and the step of applying heat to the assemblage is further defined as exposing the adhesive to a selected form of indirectly applied energy at least during the application of the vibratory blows.

11. The improved method of claim 10 wherein the adhesive is thermally responsive to an alternating magnetic field and wherein the step of exposing the adhesive is further defined as exposing the adhesive to an alternating magnetic field.

12. The improved process of claim 10 wherein the adhesive is thermally responsive to an alternating electric field and wherein the step of exposing the adhesive is further defined as exposing the adhesive to an alternating electric field.

13. The improved process of claim 10 including the step of forming an adhesive by dispersing particles of susceptor material heatable upon exposure to a selected form of indirectly applied energy in a carrier of thermally responsive adhesiveness to form the adhesive.

14. The improved process of claim 13 wherein the step of forming the adhesive is further defined as dispersing particles of a susceptor heatable upon exposure to an alternating magnetic field in the carrier.

15. The improved process of claim 14 wherein the step of forming the adhesive is further defined as dispersing particles of magnetic iron oxides in the carrier.

16. The improved process of claim 15 wherein the step of forming the adhesive is further defined as dispersing particles of gamma Fe.sub.2 O.sub.3 in the carrier.

17. The improved process of claim 11 further defined as exposing the adhesive to an alternating magnetic field having a frequency of from 0.5 to 30 megahertz.

18. The improved method of claim 17 further defined as exposing the adhesive to an alternating magnetic field having a frequency of 0.5 to 6 megahertz.

19. The improved method of claim 14 wherein the step of forming the adhesive is further defined as dispersing from 10 to 50% by weight susceptor material in the carrier.

20. The improved method of claim 8 wherein the bonding action of the adhesive is completed by the application of heat, said method including the step of applying heat to the assemblage to complete the bonding action of the adhesive.

21. The improved method of claim 8 wherein the adhesive is rendered liquid by the application of heat, said method including the step of applying heat to the assemblage to render the adhesive liquid.