US3059921A - Variable size paper folding machines - Google Patents

Description

Oct. 23, 1962 c. M. AYRE VARIABLE SIZE PAPER FOLDING MACHINES 5 Sheets-Sheet 1 Filed May 31, 1961 Oct. 23, 1962 c. M. AYRE VARIABLE SIZE PAPER FOLDING MACHINES 5 Sheets-Sheet 2 Filed May 51, 1961 Get 23, 1 2 c. M. AYRE 3,059,921

VARIABLE SIZE PAPER FOLDING MACHINES Filed May 31, 1961 5 Sheets-Sheet 3 A A f ff/f Oct. 23, 1962 c. M. AYRE 3,059,921

VARIABLE SIZE PAPER FOLDING MACHINES Filod lay 31, 1961 5 Sheets-$heet 4 C. M. AYRE VARIABLE SIZE PAPER FOLDING MACHINES 5 Sheets-Sheet 5 Filed May 31, 1961 ilnited htates Patent G VARIABLE SIZE PAPER FDLDING MACHEJES Comley Milhurn Ayre, Mangotsfield, England, assignor to Strachan tit Henshaw Limited, Bristol, England, a

company of Great Britain and Northern Ireiand Filed May 31, 1961, Ser. No. 113,831 Claims priority, application Great Britain June 1, 1960 2 Claims. (Cl. 270'72) This invention relates to variable size paper folding machines, and particularly to paper folding machines which are associated with a rotary printing machine whereby to cut olf sheets from a continuous web issuing from the printing machine and to fold the said sheets to form a folded product.

Usually, the folding machine is so connected to the printing machine that the speed of rotation, in terms of revolutions per minute, of the various rolls or cylinders of the folding machine is related to the speed of rotation of the printing cylinder of the printing machine.

The surface speed of the printing roll or cylinder must always be equal to the speed at which the web enters the printing machine, because otherwise the web would be either ruptured or crumpled. If a larger diameter printing cylinder has to be mounted in the printing machine in order to print longer printing repeat lengths, the ratio of rotation of the printing cylinder to other rolls in the machine will have to be varied in order to retain the surface speed of the printing cylinder equal to the speed of entry of the web to the machine, because a larger cylinder will have a greater peripheral length and therefore more web will issue from said cylinder for each revolution thereof.

However, the various rolls or cylinders of the folding machine almost invariably rotate at a fixed ratio to the printing cylinder. Consequently, it has been the usual practice to make the primary folding cylinders, that is, the cylinders which effect the first or only folding of the web after it leaves the printing machine, of a size such as to rotate with a surface speed at least equal to that of the longest printing repeat length effected by the printing machine. If the surface speed of the printing cylinder, for example, a smaller diameter cylinder, is less than the surface speed of the primary folding cylinders, to produce a shorter printing repeat length, the printed sheets, cut off from the web after printing, must be accelerated up to the surface speed of the folding cylinders by, for example, forwarding tapes or other devices. This results in the loss of positive control of the sheets before they reach the folding cylinders, and is the main reason limiting the speed of a variable size folding machine and also for the difiiculty of maintaining fold accuracy as compared with a fixed size folder.

In order to avoid some of the said disadvantages of a variable size folding machine it has been proposed to provide a primary folding cylinder of variable diameter so that the peripheral length of said folding cylinder could be varied to give the cylinder at surface speed equal to that of the printing cylinder, thus eliminating the necessity for forwarding devices and enabling the web and cutoff sheets always to be under positive control of gripping or other devices. Such a variable size primary folding cylinder is disclosed in patent specification No. 2,814,484 which cylinder first operates upon the web in conjunction with a web severing roll to sever the web into sheets, and then operates in conjunction with a secondary folding cylinder to fold the sheets. Whilst the primary folding cylinder was variable in size in order to give it a peripheral length equal to that of the printing cylinder, the secondary folding cylinder was of fixed size and peripheral length to give it a surface speed at least equal to the 3,059,921 Patented Oct. 23, 1962 paper speed for the longest printing repeat length, and therefore a speed differential existed at the first folding couple, that is, between the primary and secondary folding cylinders; the tucker blade carried by the variable size primary folding cylinder moves at true paper speed, whilst the co-acting jaw on the fixed size secondary folding cylinder moves at the paper speed for the longest repeat length.

The object of the present invention is to provide improvements in variable size folding machines.

According to this invention, the first folding couple of a variable size folding machine comprises two cylinders each of which is variable in peripheral length.

Each of the said variable size folding cylinders is adapted to be varied in size to give a peripheral length which results in a surface speed equal to that of the printing cylinder. One of the said variable size folding cylinders is provided with knives and folding jaws for cooperation, respectiveiy, with knife slots or anvils and tucker blades on the other said variable size folding cylinder so that both the cut-off of the sheets from the web (or from the series of superimposed ribbons into which the web may have been slit) and the first folding of the sheets are effected by the said first folding couple.

One embodiment of the invention is shown in the accompanying drawings, wherein:

FIG. 1 is a diagrammatic view showing the two rolls or cylinders of the first folding couple .in the folding machine, together with subsequent transfer and delivery rolls or cylinders and chopper fold units.

FIG. 2 is a transverse sectional elevation of the two cylinders of the first folding couple, showing only the segmental elements and supporting elements immediately associated therewith which provide the peripheries of the said cylinders.

FIGS. 3 to 12 are diagrammatic views showing various operations of the cylinders.

FIG. 13 is an elevation of a chopper fold unit.

FIG. 14 is a sectional elevation showing detailed construction of the two cylinders of the first folding couple.

FIG. 15 is a sectional elevation showing detailed construction of the transfer and delivery cylinders.

The two variable size cylinders comprising the first folding couple of the folding machine will be referred to, respectively, as the pin cylinder 11 and the knife cylinder 12.

The pin cylinder 11 is provided with three sets of tucker blades 13 at equal angular spacing around the cylinder, and three knife slots or anvils 14 also spaced apart at equal angular spacing around the cylinder, each knife slot 14 being disposed susbtantially medially between two angularly adjacent tucker blades 13 which are retractable below the surface of the cylinder in a known manner. Adjacent to each knife slot 14, and slightly spaced therefrom in a trailing position relative to the direction of rotation (indicated by the arrow 15) of the cylinder 11, there is a series of pins 16 which extend along the cylinder, the said pins normally projecting beyond the surface of the cylinder but being retractable to be below the surface of the cylinder in known manner.

In similar manner, the knife cylinder 12 is provided with three knives 17 at equal angular spacing around the cylinder, and three folding or gripper jaws 18 also spaced apart at equal angular spacing around the cylinder, each gripper jaw 18 being disposed medially between two angularly adjacent knives 17.

The pin cylinder 11 and the knife cylinder 12 rotate in opposite directions (the rotation direction of the cylinder 12 is indicated by the arrow 19) to provide a bite into which a web 20 or superimposed ribbons pass. During rotation of the said cylinders, the knives 17 register and co-operate With the knife slots 14, whilst the tucker blades 13 register and co-operate with the folding or gripper jaws 18.

Each said variable size folding cylinder 11 and 12 may be of any suitable construction which will enable them to be varied in size to vary the peripheral length. For example, they can be of the kind disclosed in patent specification No. 2,814,484, wherein, referring to 1 1G. 2, each cylinder 11 and 12 has a shaft 21 which has mounted on it two spaced apart end discs 22 (only one such end disc on each cylinder is shown in FIG. 2) which are provided with six radial slots 23 equally spaced apart angularly. Two series of support members 24, 25 are pro vided at each end of the cylinder, the support members 24 of the first series alternating around the end discs 22 with the support members 25 of the second series. Each support member 24, 25 is provided with a boss which slides in a radial slot 23 so that the support members may be moved radially of the axis of the shaft 21.

Each cylinder 11 and 12 also comprises a set of three segmental elements 26 each of which extends along the cylinder between the two end discs 22 and is secured rigidly to the support members 24.

Blocks 27 carried on the support members 24 at the centres of the segmental elements 26 in the knife cylinder 12 house the knives 17, whilst blocks 28 (see FIG. 14) carried on the support members 24 at the centres of the segmental elements 26 in the pin cylinder 11 house the tucker blades 13. The gripper jaws 18 are mounted on the support mebers 25 in the knife cylinder 12, and the said jaws are located between the adjacent edges of two circumferentially adjacent segmental elements 26. Similarly, the knife slots or anvils 14 in the pin cylinder 11 are mounted on the support members 25 in that cylinder, and the pins 16 project through said anvils which are located between the adjacent edges of two circumferentially adjacent segmental elements 26.

In order to vary the peripheral lengths of the two cylinders 11 and 12, the support members 24 and 25 are moved radially in the slots 23 by the means disclosed in the patent specification No. 2,814,484 which include the scrolls 29 (FIG. 14). Different segmental elements 26 of different arcuate length appropriate to the required peripheral length of the roll are mounted on the support members 24 after the positions of the support members have been varied, so that the cylinders have substantially continuous peripheries.

The size of the cylinders 11 and 12 having thus been adjusted to give them each a peripheral length which will produce a surface speed equal to the surface speed of the printing cylinder of the associated printing machine, they are locked at that size, and thereafter the said two cylinders operate as fixed size cylinders.

The printing cylinder has a peripheral length equal to two printing repeat lengths so that it prints two impressions on the web 20, to provide two printing repeat lengths, hereinafter referred to, for convenience, respectively, as repeat length A and repeat length B, during each revolution. The two variable size cylinders 11 and 12 of the first folding couple each are adjusted to have a peripheral length equal to one and one-half times the peripheral length of the printing cylinder, that is, equal to three printing repeat lengths. Consequently, whilst during one revolution of the first folding couple a pair of co-operating knife 17 and knife slot 14 will operate to sever the web at the leading edge of a printing repeat length A, during the next succeeding revolution of the said folding couple the same knife and knife slot will sever the web at the leading edge of a printing repeat length B.

If the folding machine is to fold straight, that is, without collecting one repeat length on to another repeat length, cams Within the two cylinders 11 and 12 of the first folding coupling are set to cause all of the knives 17, pins 16 and tucker blades 13 to effect each function once during each revolution of the said two cylinders.

Immediately after the first cut-off at the leading edge of the first repeat length A of the web 20, the adjacent pins 16 on the pin cylinder 11 take hold of said leading edge and carry the repeat length A partly around the pin cylinder 11 (FIG. 3).

When the next angularly adjacent tucker blade 13 and gripper jaws 18 register with each other in the bite of the two cylinders 11 and 12 (FIG. 3), the tucker blade 13 pushes the web 211 into the jaws 18 on the knife cylinder 12, thereby forming the first transverse or parallel fold line on the repeat length A, and the said jaws 18 grip the length at the said fold. Simultaneously, the pins 16 which have carried the leading edge of repeat length A approximately one-sixth of the way around the pin cylinder 11 release the said edge, and the section of severed and folded web is carried around the knife cylinder 12 by the gripper jaws (FIG. 4).

When the next angularly adjacent knife 17 and knife slot 14 register with each other at the bite of the two cylinders 11 and 12 the web 211 will be severed at the trailing edge of repeat length A and at the leading edge of repeat length B, and the next pins 16 will take hold of the leading edge of repeat length B (FIG. 4). The repeat length B will be folded in similar manner to repeat length A and, when severed to form another section of folded sheet or sheets, will follow the previous section around the knife cylinder 12 but with a gap between the two sections which is equal to approximately one-half the length of a repeat length because each section of severed sheet or sheets has now been folded substantially medially of its leading and trailing edges.

During all of the above operations, the severing or cut-off of the repeat lengths to form sections, and the tucking or folding have taken place at the true paper speed, and at all stages the sections of sheets have been under positive control either of the pins 16 or of the gripper jaws 18.

The subsequent operations of the folding machine may now be effected at any suitable speed, entirely unrelated to the surface speed of the web 20 as it issues from the printing machine, and without regard to variations in printing repeat length, because the gap created between adjacent folded sections allows such further operations to be effected at reduced speed without a trailing section fouling a preceding section.

If it is desired to collect before folding, that is, to superimpose a repeat length B upon a repeat length A, and then fold the two repeat lengths as one unit to form a signature, cams within the two variable size folding cylinders 11 and 12 are adjusted, in known manner, to cause the pins 16, tucker blades 13, and gripper jaws 18 to operate in the following way.

The leading edge of repeat length A is taken, by the appropriate pins 16, around the pin cylinder 11, but the tucker blade 13 appropriate to that repeat length will not operate nor will the pins 16 release the repeat length A. Consequently, the repeat length A will be carried, unfolded, all of the way round the pin cylinder 11 and when the leading edge thereof again enters the bite between the two folding cylinders 11 and 12 the leading edge of the second next following repeat length B will be severed and registered with the leading edge of the repeat length A, and the pins 16 which already engage repeat length A will also engage the leading edge of the repeat length B. The two repeat lengths A and B (repeat length A is now, in fact, a severed, but unfolded, section of a sheet or sheets) then are carried together approximately one-sixth of the way around the pin cylinder 11 whereupon the tucker blade 13 and gripper jaws 18 which then will register with each other in the bite will operate to fold and tuck the two repeat lengths into the said gripper jaws substantially medially of their leading and trailing edges. Almost simultaneously, the pins 16 will release the leading edges of the two repeat lengths and the superimposed sections, now folded as one unit to 6 form a signature, will be taken by the gripper jaws 18 around the knife cylinder 12 (FIG. 8), the trailing edge of the repeat length B being severed in the bite of the two folding cylinders 11 and 12.

Obviously, the first repeat length B, that is, the repeat length next succeeding the first repeat length A, will not be superimposed on a repeat length A, and will be discarded in the known manner.

It will be seen that when the folding cylinders 11 and 12 are collecting, the appropirate cams within the cylinders will be driven in a 3 to 2 ratio to the cylinders so that the operations of each tucker blade 13 and the retraction of the pins 16 will be effected only once in two revolutions of the said two cylinders.

The folded product, either straight or collected, can now be transferred (FIG. to leading edge grippers 30 in a transfer cylinder 31 which is adjacent to the knife cylinder 12 of the first folding couple. As there now is a gap between successive products, the transfer cylinder 31 can rotate at a surface speed which is considerably slower than that of the cylinders 11 and 12 of the first folding couple. The transfer cylinder 31 is of fixed size, and the ratio of slow down of the products will depend upon the length of the printing repeat length. As it is established practice in folding technique to employ slow-down ratios in excess of the printing repeat lengths envisaged, the transfer ratio will always be comparable with standard practice on fixed size folders.

Having overcome the difiiculties of speed differences common to previous variable size folders, and now having a single fold section being carried on a fixed size transfer cylinder 31, it is now possible for subsequent operations to be carried out Without regard to changes of printing repeat lengths. In this particular design several permutations of final product are possible.

Firstly, the leading edges of the sections can be transferred from the leading edge grippers 30 on the transfer cylinder 31 to leading edge grippers 34 on a delivery cylinder 35 (FIG. 6) from which the sections can be stripped (FIG. 7) into lower forwarding tapes 36 which feed to and through a lower chopper fold unit 37, thus delivering single parallel folded sections, the term parallel referring to a fold which is parallel to the axes of the cylinders. The chopper fold unit is referred to hereinafter, and in the present case is inoperative.

Secondly, by the insertion of tucker blades 38 in mountings provided on the transfer cylinder 31, and adjustment of the angular position of the delivery cylinder 35, also adjustment of the position of release of the gripper cam of the transfer cylinder 31, a double parallel folded section may be produced. The leading edge grippers 30 of the transfer cylinder 31 now carry the single parallel folded section past the previous release point, where transfer took place into the leading edge grippers 34 on the delivery cylinder 35, and only release the section after the tucker blades 38 on the transfer cylinder 31 have pressed the section into gripper jaws 39 on the delivery cylinder 35 (FIG. 9) to form a second fold. The sections are then carried around the delivery cylinder 35 by the gripper jaws 39 (FIG. and are released by the grip per jaws 39 into the forwarding tapes 36 (FIG. 11).

Thirdly, further modifications of the cam mechanisms on the transfer cylinder 31 and on the delivery cylinder 35, and removal of the tucker blades 38, permits alternate single folded sections to be delivered from the transfer cylinder 31 by forwarding tapes 32 to an upper chopper fold unit 33, whilst the other sections are transferred to the delivery cylinder 35 and thence to the lower chopper fold unit 37.

As is well known in the art, a chopper fold unit (FIG. 13) comprises a pair of rolls 40, having their axes parallel to each other and to the direction of travel of the section, and being spaced slightly apart from each other, or some other device which provides a slot parallel with the direction of travel of the section, together with a blade 41 which is caused to descend, in the manner of a chop per, on to the section when the latter is disposed over the slot or space and so press and fold the section through the slot or space, thereby providing a fold in the section which is at right angles to the previous fold or folds; the thus folded section is carried away from below the said rolls 40 or slot device.

It has been found that when a sheet or group of superimposed sheets is given a first fold and then is given a second fold which is at right angles to the first fold, a disfigurement which is known as a dogs ear is created at the junction of the first and second folds due to the inner and outer surfaces at the fold being of different lengths whilst the paper at the said outer and inner surfaces is in the same sheet, thus causing the paper at the inner surface to wrinkle, the wrinkles subsequently being changed to creases due to the pressure applied by the folding operation, the severity of the dogs ear effect. being dependent on the thickness of the sheets and the number of the sheets constrained by the first transverse fold.

The dogs car can be reduced by delaying collection of the sheets until after folding transversely to the direction of travel. The number of sheets constrained by each transverse fold thereby is reduced and the sheets can more readily adapt themselves to the different distances around the chopper fold. Such a product, formed by two previously folded sections, can be referred to as inserted chopper folded sections, the term inserted meaning that the final product has the appearance of one section inserted within another.

A fourth permutation of the folding machine enables such inserted chopper folded sections to be produced. A cam setting is provided on the transfer cylinder 31 by which all sections are transferred to the delivery cylinder 35. Means are provided for driving cams actuating collect grippers 4 2 (FIG. 15) on the delivery cylinder 35 so that alternate sections are carried completely round the delivery cylinder 35 (FIG. 12) and collected onto a section transferred from the transfer cylinder 31 to the delivery cylinder 35. The two sections are fed simultaneously to one chopper fold unit.

It will be seen that the folding machine according to this invention combines a number of features. It is a variable size folder with all essential actions comparable with a fixed size machine, and by adjustment of the various cam mechanisms a wide variety of folded products can be produced. There are no change parts as such, other than the insertion or removal, when required, of the transfer tucker blades on the transfer cylinder.

Examples of the detailed construction of the pin cylinder 11 and knife cylinder 12 are shown in FIG. 14, and of the transfer cylinder 31 and delivery cylinder 35 in FIG. 15

What I claim and desire to secure by Letters Patent is:

1. A variable size paper folding machine, comprising a first cylinder and a second cylinder both variable in peripheral length and positioned in side by side rel-ation to one another, said first cylinder being provided with tucker blades, knife slots and rows of pins, said second cylinder being provided with gripper jaw devices and knives, the said tucker blades, knife slots, gripper jaw devices and knives being so located in the respective cylinders that each tucker blade and knife slot in said first cylinder co-operates, respectively, at the bite of the two cylinders with a gripper jaw device and a knife in said second cylinder, said first and second cylinders thereby constituting a first folding couple, a third cylinder and a fourth cylinder both of fixed peripheral length, at least one chopper fold unit, said third cylinder being positioned in side by side relation to said second cylinder and provided with leading edge gripper devices so located as to co-operate with said gripper jaw devices in said second cylinder to receive folded sections of paper from said second cylinder, said fourth cylinder being positioned in side by side relation to said third cylinder and provided with leading edge gripper devices so located as to co-operate with said leading edge gripper devices in said third cylinder to receive folded sections of paper from said third cylinder, said fourth cylinder being further provided with cams for actuating said leading edge gripper devices, respectively, of said fourth cylinder, each of said cams being adjustable to cause the associated leading edge gripper device to retain a folded section of paper throughout one complete revolution of said fourth cylinder whereby to collect one folded section of paper onto a second folded section of paper, and means for feeding the combined folded sections to said chopper fold unit to produce an inserted chopper folded section.

2. A variable size paper folding machine, comprising a first cylinder and a second cylinder both variable in peripheral length and positioned in side by side relation to one another, said first cylinder being provided with tucker blades, knife slots and rows of pins, said second cylinder being provided with gripper jaw devices and knives, the said tucker blades, knife slots, gripper jaw devices and knives being so located in the respective cylinders that each tucker blade and knife slot in said first cylinder co-operates, respectively, at the bite of the two cylinders with a gripper jaw device and a knife in said second cylinder, said first and second cylinders thereby constituting a first folding couple, a third cylinder and a fourth cylinder both of fixed peripheral length, at least one chopper fold unit, said third cylinder being positioned in side by side relation to said second cylinder and provided with leading edge gnipper devices so located as to co-operate with said gripper jaw devices in said second cylinder to receive folded sections of paper from said second cylinder, said fourth cylinder being positioned in side by side relation to said third cylinder and provided with leading edge gripper devices so located as to co-operate with said leading edge gripper devices in said third cylinder to receive folded sections of paper from said third cylinder, and said third cylinder being further provided with tucker blades and the said fourth cylinder being further provided with gripper j aw devices so located that the tucker blades in said third cylinder cooperate with the gripper jaw devices in said fourth cyliner to effect a second fold in folded sections of paper.

References Cited in the file of this patent UNITED STATES PATENTS 1,903,382 Zuckerman Apr. 4, 1933 2,211,046 Barber Aug. 13, 1940 2,814,484 Stobb et al. Nov. 26, 1957

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