US3809199A

US3809199A - Machine for fashioning the structures of flexible products, and products fashioned thereby

Info

Publication number: US3809199A
Application number: US00310694A
Authority: US
Inventors: P Bessiere
Original assignee: Labinal SA
Current assignee: Safran Electrical and Power SAS; Precision Mecanique Labinal SA
Priority date: 1972-11-30
Filing date: 1972-11-30
Publication date: 1974-05-07
Anticipated expiration: 1991-05-07

Abstract

The machine is designed to produce pleated developable herring bone structures, such as used as filter elements in the motor industry. The machine includes first means for scoring longitudinal fold lines on a band transversely spaced by the width of half-chevron and for initiating folds about these lines to obtain the chevron pattern, second means for producing transverse folding lines to form the folds half-fold by half-fold and accentuate the chevrons on each half-fold, third means for imparting the final shape to the chevrons and formed by convergent differentially moving rakes directed substantially longitudinally, and fourth means for moving the fashioned structures out of the machine. The starting material comprises two tapes initially wound on respective reels and, as these two tapes pass through the machine, there is interposed therein an endless supporting tape. A novel electrical control arrangement is provided whereby the machine may be operated in automatically repeated cycles, cycle by cycle, or operation by operation.

Description

United States Patent [191 Bessiere MACHINE FOR FASHIONING THE STRUCTURES OF FLEXIBLE PRODUCTS, AND PRODUCTS FASHIONED THEREBY [75] Inventor: Pierre Etienne Bessiere, Golf Saint-nom-la-Breteche, France [7 3] Assignee: Precision Mecanique Labinal,

Saint-Dune (Seine-Saint-Denis), France [22] Filed: Nov. 30, 1972 [21] Appl. No.: 310,694

52 U.S.,Cl 93/84, 93/1 c, 270/86 51 Int. Cl B31d5/04 [58] Field of Search 93/84, 1 c, 1 W2; 270/86 [56] References Cited UNITED STATES'PATENTS 3,383,449 5/1968 Muller....; 93/1 C X Primary ExaminerRoy Lake Assistant Examiner-DeWalden W. Jones Attorney, Agent, or Firm-McGlew and Tuttle ['45] May 7, 1974 [57] ABSTRACT The machine is designed to produce pleated developable herring bone structures, such as used as filter elements in the motor industry. The machine includes first means for scoring longitudinal fold lines on a band transversely spaced by'the width of half-chevron and for initiating folds about these lines to obtain the chevron pattern, second means for producing transverse folding lines to form the folds half-fold by halffold and accentuate the chevrons on each half-fold,

' third means for imparting the final shape to the chevrons and formed by convergent differentially moving rakes directed substantially longitudinally, and fourth means for moving the fashioned structures out of the machine. The starting material comprises two tapes initially wound on respective reels and, as these two tapes pass through the machine, there is interposed therein an endless supporting tape. A novel electrical control arrangement is provided whereby the machine may be operated in automatically repeated cycles, cycle by cycle, or operation by operation.

28 Claims, 14 Drawing Figures sisosllss PATENTEDMAY 7:914

SHEET 2 BF 9 PATENTEDMAY 7 I974 3809ll99 SHEET 6 OF 9 aisosllss PATENTEDIAY 1 m4 SHEET 7 OF 9 1 MACHINE FOR FASHIONING STRUCTURES OF FLEXIBLE PRODUCTS, AND PRODUCTS FASHIONED 'I'HEREBY FIELD AND BACKGROUND OF THE INVENTION This invention relates to automatic machines and more particularly to machines the operating cycle of which includes several operations carried out by the motions of mechanical members actuated by mechanical, hydraulic and pneumatic means.

The invention relates most notably, since its most useful application would appear to lie therein, to those of such automatic machines which permit continuously fashioning the structures of pleated and/or herringbone-pattern developable flexible products usable as filter elements in the motor industry, for example.

The invention further relates to the structures fashioned by the automatic machines described herein.

Such structures are obtained from a flexible product, such as a band of treated paper or the like, and consist of a succession of accordion-type transverse pleats, each such pleat in turn embodying a herringbone pattern (or chevrons) along its entire length.

SUMMARY OF THE INVENTION It is the object of this invention to render such automatic machines, and those used for producing pleated structures in particular, such that they satisfy better than heretofore the different requirements encountered in practice.

The invention consists principally, more particularly in an automatic machine for continuously obtaining pleated developable herringbone structures, in providing first means for producing longitudinally, on the band, fold lines spaced transversely by the width of one half-chevron and for initiating a bending about these lines whereby to obtain the chevron pattern, this first means being so devised as to drive theband towards the output end of the machine; second means for producing transverse fold lines whereby to form the folds halffold by half'fold and accentuate the chevrons on each half-fold; third means for imparting their final shape to the chevrons, which third means consist of rakes having convergent differential motions in a substantially longitudinal direction; and fourth means for carrying the fashionned structures to the exterior.

The invention relates more particularly still to feed systems for such machines for discontinuously producing strip material in the form of pleated structures for making filter elements and automobile filters in particular.

In such machines the feedstock is supplied in the form of a paper band or the like, off a spool on which the paper is wound. Because of its inertia, the spool is not rotated by the band itself (as this could cause it to slip inside the machine, or to break) but by its own driving mechanism. However, because the production rate, particularly in an intermittently operating machine, may vary for different reasons, the rate at which the machine is fed with strip material must not be com stant; Added to this is the fact that, for a given linear transfer speed of the band, the spool must rotate faster and faster as it pays it out.

Hence in a machine for fashioning at least one feedstock unit supplied by an associated pay-out or feed LII unit (such as a spool, a pulley or the like), the present invention further includes the provision of a prime mover for the pay-out or feed unit, and a coupling between the prime mover and the unit and means for ac-,

tuating the doupling according to the quantity of material already supplied by the unit bu't'not yet absorbed by the machine, which means consist of at least one pulley over which the material runs before it is absorbed by the machine and the shaft of which is movable whereby to operate electrical contacts controlling the coupling. There are likewise provided conveyor means synchronized with the first tools of the machine, adapted to draw the material and positioned between the coupling actuating means and the tools thereby to entrain the material towards the tools, whereby the material isfashioned by the tools under light and constant tension.

In addition to this principal particularity, the invention includes a number of other particularities which arepreferably used together with the principal particularity and to which more explicit reference will be made hereinafter, and most notably a second particularity applicable in cases where the machine has fed into it simultaneously at least one unit of feedstock material and at least one supporting tape or the like designed to facilitate entrainment and/or fashioning of the material, characterized by the provision, between the output end of the machine and a prime mover for storing or recycling the tape means for regulating the tension of the tape at'the output end, whereby the feedstock unit is drawn out of the machine under the urge of the tape. a

The invention further includes control (and signalling) means which associate to each operation in the cycle a relay circuit so devised that the relay associated to a specific operation controls at. the same time the closure of a signalling circuit indicating that the operation has been initiated, the opening of the circuit belonging to the relay associated to the previous operation, the closure of a circuit controlling the moving elements which perform the desired operation and the closure of a circuit for preparing the next operation.

BRIEF DESCRIPTION OF THE DRAWINGS The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice. In the drawings, FIG. 1 is a general illustration of a machine according to the invention for obtaining the structures of developable pleated and- /or herringbone-pattern flexible products;

FIG. 2 is a diagrammatic view detailing the essential component parts of the machine in FIG. 1;

FIGS. 2a to 2d are alternative embodiments of means for controlling the component parts in FIG. 2;-

FIG. 3 is a plan view with partial cutaway of a first work station of the machine;

FIG. 4 is a side elevation view in a partial section of a component part of the station shown in FIG. 3;

FIG. 5 is a front elevation view in partial section of three other work-stations;

FIG. 6 is a plan view in partial section of the workstations shown in FIG. 5;

The nine parts a through i of FIG. 7 schematically i1- lustrate the nine stages in the formation of the herring-' invention;

FIG. 8 is an overall view of a feed system according to the invention, designed more specifically for an intermittent-cycle machine;

FIG. 9 shows on an enlarged scale the pay-out means for the feed system shown in FIG. 8;

FIG. 10 is the electrical wiring diagram for the control (and signalling) circuit according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, the pleated structures 1 shown therein are obtained from one or more bands 2 of a flexible material such as treated paper or the like which lends itself readily to folding, a tape 3 of flexible material which lends itself to warping being inserted between bands 1 and 2. The bands 2 are wound respectively onto pay-out spools 4, the tape 3 being an endless tape capable of being recycled, upon exit from the machine, via pulleys 5, 6 and a pulley-block a for adjusting the tension of tape 3.

The system for feeding the machine with bands 2 and tape 3 is formed by interposing, between a pulley 7 for receiving the superimposed bands 2 and tape 3 and each spool 4 or pulley 6, automatic regulating means consisting of a pulley 8 the spindle of which moves as a function of the band or tape length between pulley 7 and the spool or pulley, and this regulating means controls, through appropriately adapted means, the rotation of the spool or pulleys when the length'is inadequate. This rotation is obtained by means, say, of couplings 9 each of which is associated to one of the spools 4 or pulleys 6 and controlled by the pulley 8 over which the band or tape runs.

Upon exit from the machine, the structures 1 are guided through ducts 10, the upper duct being laterally offset in order to enable the tape 3 to be turned back more easily for recycling.

The sandwich-forming superimposed bands 2 and tape 3 run between the take-up pulley and the ducts 10 into work-stations ll, 12, 13 which will now be described with reference to FIGS. 2 and 6.

schematically illustrated in FIG. 2 are the various machine components for forming the pleats and chevrons. The bands and tapes (not shown) run leftwardly, in succession, through several pairs of pre-forming rollers 14 to 18 which make up the station 11. The rollers 18 are mounted for rocking motion on a lever 19 actuated by a jack 20 and are provided with means for entraining the sandwich 2, 3 leftwardly in intermittent fashion. These rollers gradually score on the sandwich 2, 3 longitudinal lines used later to obtained the herringbone pattern.

Work-station 12 (FIG. 2) is composed of two independent pivoting pade-like members 21, two independent stationary spades 22, rakes 23 extending in a substantially longitudinal direction and racks 24 coextensive longitudinally on either side of the sandwich. The

spades

21 and 22 are adapted to fashion the transverse pleats and initiate the chevron by squeezing the sandwich between them. The purpose of the rakes 23 is to impart the final configuration to the chevrons. The racks 24 are adapted to discharge the completed structures from the machine.

The work-station 12 may be jack-operated. Two jacks 25 control the rocking motion of respective spades 21 and are mounted on respective supports 26,

on each of which is supported a spade 21, a spade 22 and a series of rakes 23. Each support 26 is vertically actuated by a respective jack 27 mounted on a respective sliding support 28. In turn, each support 28 is longitudinally actuated by a respective jack 29 mounted on the first frame 30 of the machine. The racks 24 are actuated by a jack 31.

FIGS. 3 and 4 show the component parts of station 11 on an enlarged scale. The

rollers

14, 15, 16 and 17 are freely rotatable on fixed supports 32. The first pair of rollers is formed, on the one hand, by a roller 14 having circumferential scoring ridges 33 axially spaced by an interval equal to the width of the chevrons to be obtained and, on the other hand, by a second roller 14 having grooves 34 to match the ridges 33. I

The three pairs of rollers l5, 16, 17 serve to gradually generate a preliminary shaping of the chevron and are accordingly formed with axial symmetrical

frustoconical portions

35, 36 the number of which increases as the sandwich 2,3 transits from rollers 15 to rollers 17. The upper rollers 15, 16, 17 comprise one, three and five frusto-conical portions 35 respectively, and as many frustoconical portions 36. The lower rollers 15, 16, 17 comprise the same number of frusto-

conical portions

35, 36 as the upper rollers.

The two rollers 18 are of the same type as rollers 15, 16, 17 and may have eight frusto-conical portions 35 and as many frusto-conical portions 36. The

portions

35, 36 on rollers 15 to 18 have dimensions such that their circular edges contact the longitudinal scoring lines formed on sandwich 2, 3 by the ridges 33 and grooves 34 on rollers 14. The final stage of this set of rollers is devised so as to entrain the sandwich 2, 3 leftwardly in synchronism with the motion of rocking spades 21, whereby the resistance of rollers 14 to 17 to the forward motion of sandwich 2, 3 is overcome and all excessive downstream tension is avoided. Preferably, the resistance is adjustable according to the nature of the material used, for instance according to its thickness. Such adjustment is likewise possible on the rollers 18. To this end, spring means for restoring the rollers into mutual contact are provided. As shown in FIG. 4, these means include, for at least one roller in each pair thereof and at each of its ends, an adjustment screw 37 bearing against a spring 38 which applies a rod 39 against a shaft 40 supporting the roller. Spring 38 is prestressed and, depending on the position of screw 37, applies the two rollers against each other with an adjustable force.

The sandwich is entrained by the rollers 18 by means of a freewheel system 41 (FIG. 3) which allows the rollers 18 to rotate only in the directions of arrows A and A, and by means of lever 19 operated by jack 20. Lever 19 is pivotable about a shaft 42. When jack 20 operates lever 19 rightwardly, the rollers 18 roll over the sandwich and effect preliminary shaping of the chevrons, the sandwich being kept in place by virtue of its tension. The jack then moves lever 19 leftwardly and the freewheel system drives the sandwich leftwardly. An adjustable stop 43 limits the forward motion of lever 19.

FIGS. 5 and 6 illustrate work-station 12 when the sandwich has had its final shape imparted to it. At this station, each rocking space 21 is fixedly supported by screws 44 on an arm 45 pivotally connected to the end of the rod 25a of a jack 25. 'A link 46 pivotally connected at 47 to the corresponding support 26 is pivotally connected at 48 to arm 45. The longitudinal motion of jack rods 25a thus gives rise to a rocking motion of the spades 21, which motion is composed of the rotation of arm 45 about point 47. Each spade 22 is fixedly supported on the corresponding support 26 by screws 49. The two faces of each spade 21 are profiled so as to have a plurality of flat rectangular facets of the same width as the width of the frusto-

conical portions

35, 36 of rollers to 18 as measured on the generatrix. The two faces of spades 22 have the same profile as the faces of spades 21, thereby to ensure that the sandwich can be squeezed between an upper spade and a lower spade over the entire width of the latter and that the chevron pattern initiated by the rollers can be continued. As shown in FIG. 5, the edges of spades 21 define transverse fold lines on the sandwich and fold it.

Work-station 12 furtherincludes the rakes 23 arranged as an upper series and a lower series thereof. The rakes in eachseries are supported in a respective one of the two supports 26 by a head 50 and converge towards the exit end of the machine (FIG. 6). Each rake 23 is formed with evenly spaced teeth 51. The

rakes are positioned in pairs (one rake from each se-,

ties) in the same vertical'plane and are mutually staggered so that the teeth of one rake are positioned between the teeth of the other. In each series, alternate rakes are rigidly mounted in the support 26 (as shown inrespect of upper rake 23a in FIG. 5) whereas the other rake (23b) bears elastically at the rear against a spring stop 52. The portions of rakes 23b directed towards the output end of the machine may bear against adjustable stops 53 which are fixedly carried on the machine and limit or interdict longitudinal movement of rakes 23b. Conversely, the rakes 230 are devoid of such stops and are fast with the supports 26. Thus, rakes 23 of the same series are possessed of a differential motion which, as will be explained hereinafter, allows accentuating the chevron pattern of the folds produced by

spades

21, 22.

Each support 26 (on which are mounted two

spades

21, 22 and a series of rakes 23) is slidable vertically responsively to a jack 27 and is guided by columns 54 (see also FIG. 2). 1

Each shaping set (spades and rakes) is movable longitudinally with its support 28 responsively to the associated jack 29 (not shown on FIGS. 5 and6) mounted on its fixed support 30 (FIG. 6).

Carried on thesupport 30 above and below each rack 24 are restraining teeth 55 directed towards the output end of the machine and intended to prevent the sandwich from backing, as will be explained hereinafter;

The station 13 is a station for thermally treating the bands 2 and will not be described herein.

Operation of the machine for shaping the folds, as de scribed hereinabove, will now be described with reference to the accompanying drawings and more specifically to FIGS. 2 and 7. FIG. 7 illustrates the nine stages in the formation of the structures 1, and the arrows thereon indicate the direction of motion of the compomoved rightwardly by jack in sliding motion over the sandwich. During the second stage (FIG. 7b) upper support 26 is moved rightwardly by upper jack 29 and the upper spade 21 is rocked upwardly by upper jack 25. During the third phase (FIG. 70) the upper support 26 is lowered onto the sandwich by upper jack 27. During the fourth stage (FIG. 7d), the upper spade 21 de- I scends and the rollers 18 move the sandwich leftwardly (jack 20) thus obviating the need for spade 21 to have to pull the sandwich itself after overcoming the resistance due to the pre-shaping rollers and the pulleys 8,

r the axial displacement of the rollers being equal to the length of the folded sandwich. F urther, the racks 24 are moved rightwardly by jack 31 and, during this motion, the teeth 55 prevent the sandwichfrom drawing back responsively to the racks. During the fifth stage (FIG. 7e), the rollers 18 are moved rightwardly by the jack 20 and the lower support 26 (lower spades and rakes) is lowered During the sixth stage (FIG. 7f), the lower support 26 is moved rightwardly by lower jack 29 and the lower spade 21 is rocked downwardly by lower jack 25. During the seventh stage (FIG. 7g), the lower support 26 is returned upwardly by lower jack 27. During the eighth stage (FIG. 711) the lower spade 21 is rocked upwardly by lower jack 25 to form a half-fold, at the same time as the rollers .18 are moved leftwardly by jack 20. Lastly, during the ninth stage (FIG. 7i) the two supports 26 are moved back leftwardly by jack 29 and entrain the sandwich along the width of a fold, and at the same time the racks 24 are moved leftwardly by jack 31. In the course of this latter motion, the teeth 24a of racks 24 grip the edges of the sandwich (FIG. 6). At the end of the cycle acomplete foldhas thus been formed by the motions of the four spades. 21, 22.

Upon exit from the

spades

21, 22 the folds have been formed but the chevrons'have barely been initiated. As shown in FIG. 6 in the case of the rakes in the upper series thereof, the teeth 51 of rakes 23a (when the latter have descended) engage between two folds and more specifically in areas where the chevronforming facets converge towards the output end of the machine. Conversely the teeth 51 of rakes 23b engage in areas 156 where the chevron-forming facets converge towards the input end of the machine. During the ninthstage in the fold-formingcycle (FIG; 7i), all the rakes are urged leftwardly by their supports 26, and, whereas the rakes 23a effect full travel, the rakes 23b abut at 53 and are halted. As a result, the rakes 23a exert on the sandwich, andmore specifically on the chevron crests 157, a thrust towards the exit end, whereas the rakes 23b, cause the band to be restrained by the rear edges of the areas 156. This differential action by the rakes 23a, 23b in the same set thereof accentuates the chevrons, causing them to assume their final shape. At the same time, the sandwich narrows in width and, to obtain this effect, convergent lateral guides 158 are provided on the fixed support 30 to compensate for the reduction in widthof the sandwich. At each cycle, the rakes in the same setthereof move longitudinally through a distance equal to one foldpitch. On exit from rakes 23 to the chevron retain their shape by'virtue of the lateral guides formed by the racks 24, but their spacing is increased by a shifi of the upper racks equal to thepitch of the chevron folds, as shown in FIG. 6.

Whereas in the embodiment hereinbefore described with respect to operation of the mechanical components for fashioning the chevron folds, recourse is had to fluid-control, it is to be understood that any other convenient means may be used. For instance, as shown in FIGS. 2a and 2b, recourse may be had to purely mechanical means such as a central camshaft 81 rotating at constant speed and carrying cams 82 each of which 'is associated to one or more mechanical fold-forming members. Each cam 82 cooperates with a follower 83 carried on a pushrod 84. Each pushrod 84 transmits its motion directly to a movable element supported directly on the frame 30, examples being the supports 28 or the racks 24. This motion is transmitted mechanically in any convenient manner, such as by transmission means 85 carrying an end stud 86 cooperating with an oblique ramp 87 supported by a movable element 28, 24 (FIG. 2a).

Considering next the motions of the moving parts supported in turn by the movable elements (such as the moving parts 26 carried by the movable supports 28), these are transmitted through the agency of lateral flanges 88 used as tracks along which followers 89 fast with pushrod 84 roll on either side (FIG. 2b). This sys tem permits positively actuating these elements irrespective of the position of the movable supporting members. The tracks associated to the several supports 26 would be horizontal, whereas the tracksassociated to the movable members 25a which actuate the spades 21 and are carried by the same supports 26 would be vertical. In the cases of the members 25a the profiles of the actuating cams would be determined by the composition of the two motions of the supports 26..

Illustrated in FIG. is an alternative embodiment for controlling the mechanical means. A shaft 91 rotating at constant speed rotates flexible transmission means 92 via drive connections 91. These flexible transmission means carry a terminal cam 94. For exemplary purposes, such a control system is illustrated in respect of upper support 26. The cam 94 drives a follower 127b carried a rod 127a which actuates upper support 26. Clearly, such a control system may be applied likewise to the other mechanical components.

As shown in FIG. 2d, the camshaft 81. (FIGS. 2a and 2b) and the pushrod 84 may be associated to a hydraulic transmission system. To this end, two cams 82 are provided for each movable element to be actuated. Each associated pushrod 84 carries a piston-rod 95 of a piston movable in a cylinder 96, each cylinder being connected to one chamber of a jack 97 whose rod 98 directly actuates a movable element in both directions, such as an

element

24, 26, or 28.

As shown in the alternative embodiments in FIGS. 2a 2b, 2c and 2a, it is accordingly possible to actuate the foldforming mechanical elements either by purely mechanical means or combined mechanical and hydraulic means.

If use is made of fluid-jacks not governed by a mechanical master unit, they may controlled in different ways. For instance fully pneumatic control may be utilized with the aid of pneumatic logic cells from which a signal announcing the end of an operation triggers the next operation either by being converted into an electrical signal activating an electrically operated jack valve or by being amplified for directly controlling the intake of fluid into the jack.

Alternatively, combined electrical and fluid operation may be utilized through the agency of a cam-

type leys

116, 117, 118 in the direction shown by the arrows controller or of a stepwise operating device activated by the limit switches.

However. it is preferable to use an electric circuit with relays in view of its endurance.

Whereby, and irrespective of the form of embodiment adopted, it is possible to devise an-automatic machine more specifically for producing-developable herringbone-pattern pleated. structures, the description and manner of operation and utilization of which have been given hereinabove and which offers various advantages, including the followings;

an invariably low working tension for the bands, thereby avoiding any risk of tearing; v

the existence of an intermediate tape 3', enabling the structures 1 to be withdrawn from the machine easily without having to pull them;

'the use of a linkage system for rocking the spades'21,

the stroke of the jack pistons or the travel imparted by the cams.

The following or a similar procedure may be adopted for the purpose of providing a feed system for the machine.

Considering firstly the machine 101 it includes a take-up pulley 105 for the

bands

103, 104, workstations 106 for producing the structures, a control and monitoring station 107, output ducts 108 for the'structures 102 and an output pulley 109 for the intermediate tape 104. The bands 103 are supplied from spools 110 fixedly supported on rotation spindles 111 and the intermediate tape 104 is supplied from a driving pulley 113.

In accordance with a first teaching of the invention, driving means are provided for the spools 110 and the pulley 113, which means consist of a motor 114 (FIG. 9) which through an endless belt 115 drives three pul- A. Each of these pulleys is fast with the driving portion 118a, 119a, of a

coupling

118, 119 the other portion 118b, 11% of which (FIG. 8) is fast with the spindles 111 of the spools 110 and the pulley 113.

The bands 103 upon issuing from the spools 110, and the intermediate tape 104 upon issuing from the pulley 113, run over respective first intermediate pulleys 120 (FIG. 8) and then over respective second pulleys 121 each having its spindle fast with a respective arm 122 (FIG. 9) which is pivotally connected to an axle 123 and possibly subjected to the action of a lightening spring. Each arm 122 carries a' contact stud 124 adapted to operate four

contacts

125, 126, 127, 128, of which

contacts

125, 126 control the rotation of a spool 110 or of a pulley 113 and

contacts

127, 128 are safety contacts. Although only one set of contacts is shown in the drawing, two further identical sets are obviously provided for the other two arms 122.

The electrical connections (not shown on FIGS. 7 and 8) for

contacts

125, 126, 127, 128 are as follows:

contacts

127 and 128 control complete stoppage of the machine. The same applies to the other two sets of contacts associated respectively to pulley 113 and to the other spool 110.

In accordance with a second teaching of the invention, there is provided, between the take-up pulley 105 of

sandwich

103, 104 and the first fashioning tools (not shown in FIGS. 7 and 8) that draw the sandwich into the machine, conveyor means synchronized with the tools and adapted to prevent excessive tensioning of the sandwich and hence of the bands.103 between spools 110 and pulley 113, on the one hand, and said first tools on the other. These means may be devised in any convenient manner and, in the event that the tools draw the

sandwich

103, 104 intermittently, recourse is had to means for likewise entraining the sandwich intermittently and in synchronism with the tools. In the illustrated embodiment (FIG. 8), these means are formed by two rollers 129 between which the

sandwich

103, 104 extends and which are supported for freewheel motion on an arm 130 capable of rocking about a horizontal spindle 131. The freewheel system is so mounted that the rollers 129 entrain the

sandwich

103, 104 leftwardlywhen arm 130 rocks leftwardly.

The rollers 129 may possibly be disposed among the tools for fashioning the

sandwich

103, 104 provided that those of the tools which are located between the rollers 129 and the pulley 105 exert noexcessive tension on the sandwich in operation.

Thus, the provision of these conveyor means avoids the need for the tools to have to pull the sandwich 103,

104 into the machine themselves, since this could cause tearing of the sandwich if the tools have sharp edges. Instead, the sandwich, which is entrained without difficulty by the conveyor means, is fashioned by the tools at low and constant tension.

In accordance with a third teaching. of the invention,

there-is provided, between the pulley l09for taking up the supporting tape 104 when it exits from machine 101 and a means for storing or recycling the tape, means for regulating the tape tension adapted to assist in discharging the

sandwich

103, 104 at. low tension.

Depending on the available height, these means may consist of a single or double sheave pulley-block 132. In FIG. 8 this pulley-block includes a burden 133 and two pulleys 134. The burden 133 is acylinderresting on the length of tape 104 available between pulleys 134. As it bears on the tape 104, the burden 133 produces therein a constant tension throughout the length included between pulley 10 9and first pulley 134. p

In the illustrated embodiment (FIG. 8) the tape 104 is of the endless type and is recycled on exit from the machine. After the second pulley 134, tape 104 runs over two intermediate pulleys 112 and then over driving pulley 113. In order to allow tape 104to be returned backwards easily, upper duct 108 is offset laterally. t

This being so, operation of a feed system according to this invention is as follows. Motor 114i: started up i and drives

pulleys

116, 117 in the direction of arrows A. For the purpose of fashioningthe, bands, the machine 101 uniformly absorbs the three superimposed thicknesses of bands 103 and tape 104 supplied to it synchronously by the rollers 129. If it is assumed that the arms 122 initially occupy the position shown in FIG. 9, the spool 110 and the pulley 113 will be motionless (contacts 125 inoperative) and the length of band and tapebetween pulley 105, on the one hand, and spools 110 and'pulley 113,011 the other decreases. Hence each arm 122 rocks upwardly (arrow C, FIG. 9) until its stud 124 operates the contact 125 and thereby causes the spool 110 or the corresponding pulley 113 to be rotated by the

coupling

118 or 119. Preferably, rotation is such that the linear pay-out speed is at least equal to the average speed at which the band and the tape enter the firststation 106. Once rotation has been triggered, arms 122 rock in the direction of arrows D (FIG. 9) under the effect of their own weight, the weight of pulleys Y121, and the force of a possible return spring for arm 122, whereby the band 103 and the tape 104 are tensioned. This rocking motion ceases when the studs 124 operate the contacts 126 and thereby arrest rotation of spools 110 and pulley 113. Arms 122 gradually rise again as the tape is'entrained into the machine, and the cycle recommences. Thus the bands 103 and the tape 104 are supplied to machine 101 at a'low tension which is determined by the effect of the weight of pulleys 121 and of arms 122 and the restoring force-of a possible spring exerted on arms 122.

It will be noted that whenpulley 113 is motionless, the pulley-block 132 absorbs the output of intermediate tape 104 by reason of the descent of burden 133, thereby ensuring constant tension in the tape, whereas when pulley ll3jis driven the burden 133 rises at the same timeas central pulley 121 descends. When it leaves the machine, the

sandwich

103, 104 of each structure 102 passes through aduct 1 08, and the tape 104 under tension unfolds and resumes its initial flat shape at the same, time as it carries the structures 102 outwards without having topullon them. Because tape 104 is endless, the stop-start cycle of pulley 113 is substantially even.

In contrast, as the spools lloiunwind, the linearpayout speed of bands 103 whenithe spools uomme de creases for a given machine feedrate. Hence the spools 110 rotate for increasingly longer periods of time. The minimum angular velocity to be imparted to spools 110 and hence to pulleys 116 must be such that the linear speed at which the bands 103m paid out is equal to the rate of absorption by the machine.

Should one of the contacts 125 fail to trigger immediate rotation of the spool or of the corresponding pulley 113 for any reason, then the corresponding arm 122 will continue to pivot in the clirection of arrow C responsively to thetension in the rape until its stud 124 operates the corresponding safety contact 127 and stops the machine 101. A contactIZ'Z may be operated likewise when a band 103has been. fullyunwound and itsend is. restrained bythe hub of itsspool110. Safety contacts 128, whichlikewise arrest themachineareop erated either when a bandwrtape) breaks orif the endsof the band are not restrained by the spool hubs when the spools are emptied.

Thereby, and irrespective of thet'orm of embodiment adopted, it is possible to devise afeed system for a niachine, notably an intermittently runningmachine, the operatingprinciple of which systemhas beendescribed hereinabove and whichoffersvariousadvantages, and s the followingin particular:

being thus fashioned under low and constant tension;

it discharges the fashioned structures without the need to exert a pull on them.

It should be noted that the tape 104 may alternatively not be of the endless type but paid out (like the bands 103) from a spool, in which case the tape would upon exit from the machine be wound onto another spool the rotation of which would be controlled according to the position of burden 133.

The following provisions may be made for controlling the above-described system. In the diagram shown in FIG. 10, each operation in the machine cycle has an associated circuit designated by a sufiix letter a, b, c n assigned to each of its components. Each circuit energizes a relay which effects the signalling as well as the control functions in the operation. This is most important in an automatic continuous-cycle machine since,

' in the event of a failure, it allows determining during that is actuated, at the end of its travel, by the component effecting operation n. Similarly, contact 202b of relay lb is closed by pushrod 203a, and so automatically, each operation being initiated by completion of the previous operation. In some cases it may be necessary to slave a relay circuit to completion of several previous operations, in which case the circuit may comprise a plurality of series-connected contacts 202 each operated by a pushrod that isactuated by a specific operation. Suchan arrangement is shown in the case of relay circuits a, c, g,for example.

One of the terminals of each contact 202a, 202b 202n is electrically connected'to a common supply 204 through relays 201a, 20lb 201n. The'other terminal is connected to a circuit comprising two branches, a control branch for the corresponding relay and a branch for self-energization of the same relay. The control branch includes a normally-open contact 205 and the other branch a first normally-closed contact 206 and a second normally-open contact 207. Connected into contact branch 205a of the first relay circuit is a normally-closed contact 208 in series with contact 205a and operated by relay 20lb. These parallel-connected circuits have their common outputs connected to a contact stud 209 of a rotary selector 210 having (ai r sitba t r are Over-aims 1. 1. 111.

Provided on each relay circuit, between the limit switch or switches and the two-branch parallel circuit, is a terminal connected to one of the other contact studs 209a, 2091; .209n, arranged in that order inside a selector 210. The central contact stud of the selector is connected to the other terminal 240 of the voltage supply source through a master switch 211.

Connected in parallel to the circuit having as its terminations the central selector stud and the common output from relays 102 are the following:

a signalling circuit 212 controlled by a switch 213, each branch of which includes in series a normallyopen contact 214 and a signalling lamp 215;

a control circuit 216 for the actuators 218b, 218a 218n effecting the respective operations, which circuit comprises at least n parallel-connected branches each consisting of a normally-open contact 217 and an electrically-operated actuator; t

and an automatic operation activating branch 219 comprisingin series a normally-closed manual pushbutton 220, a relay 221 and two parallel-connected contacts 222, 223, of which contact 223 is the contact for self-energizing relay 221 and the contact 222 is a normally-open manual pushbutton for energizing relay 221. v

Finally, parallel-connected to contact 205a and 208 of the first relay circuit is a normally-open manual pushbutton 224 for activation of the cycle.

Shown in dot-dash lines in the case of relay 201a are the actions of the latter on those of the contacts in the ply current to the relay controlling the previous operation b;

closure of the self-energization contact 2070 of the relay;

closure of contact 205d ready for energization of the relay 201d controlling the next operation d;

and closure of the .contact controlling activation of actuator 218c associated to the third operation c.

The same applies to the other relays. It will be noted in particular that a relay operates the contacts belonging to the relay circuits associated to the previous and subsequent operations. Hence a special circuitry must be provided for the relays of the terminal operations of the cycle.

This circuitry must be such as to permit either fully automatic operation or cycle-by-cycle semi-automatic operation. To this end, relay 2010 upon being energized opens the contact 206n of the last circuit and its other actions are similar to those of relays 201a to 201n. As for relay 201n, it has no action on the contact 205a of the first relay circuit, which is caused to be controlled by relay 221 (the line of action is shown in dot-dash lines).

This being so, the principle of operation of this electrical system, as associated to an automatic machine, will now be described with reference to FIG. 10.

For operation in the automatic mode, master switch 211 is closed, selector 210 is moved-to position 209 and the push-button 221 controlling relay 221 is depressed. The latter is then energized and remains so by virtue so its self-energization contact 223, which it closes. Throughout operation in the automatic mode, this relay will remain energized. It closes contact 205a which activates relay 201a associated to the first operation. This contact will also remain closed throughout operation in the automatic mode. At the start of the cycle, pushrods 203;: are in their positions corresponding to the end of the previous operation, hence the contacts 202a are closed. Relay 201a is thus energized branch of relay energized since a cycle is beginning);

via the

circuits

240, 211, 225, 209, 205a, 202a, 204 and therefore causes:

initiation of the first operation by closing the contact 217a activatingactuator 218a;

lighting of the lamp 215a indicating that the first operation has been activated;

opening of contact 206n of the self-energization 201n (the latter being already deself-energization of relay 201a by-closure of contact 207a and preparation of a second operation by closure of the second relay circuit contact 205b.

The first operation (activated by ,energization of relay 201a) continues, responsively to the actuator, until the latter reaches the end of its'travel, whereupon it closes contact 202b via pushrod 203a so that relay 20111 is energized via

circuit

240, 211, 225, 209, 205b,

I 202b, 204. Being thus energized, relay 2011) causes the following:

activation of actuator 218b (by closing contact preparation of the third operation (by closure of contact 205c);

opening of the self-energization circuit of relay 201a andopening of contact 208, whereby relay 201aisrendered inoperative;

' closure of its self-energization circuit (by closing contact 2071));

and signalling of the second operation (by closure of contact 2 l4b).

At the end of the second operation, contacts 201a "are closed and relay 2010 is energized.

The cycle continues thus until the final operation. During the latter, relay ln is energized but does not operate on the first relay circuit. At the end of this operation, contacts 202a close and relay 201a is energized if at least one of the three energizing branches is closed. The right-hand branch is opened (contact 207a open), the left-hand branch likewise (pushbutton 224 not depressed), but the'central branch is closed by the contact 208 and the main relay 221 if branch 219has not been opened in the meantime. Relay 201a is then energized and the cycle recommences, whereby automatic operation with repeated cycles is obtained.

Operation in the automatic mode can be interrupted a in two ways, either by opening; master switch 211,

thereby instantly stopping the machine (safety switch), or by pressing pushbutton 220 which arrests operation at the end of the cycle. This latter action opens the branch 219 and de-energizes relay 221, which opens the contact 205a for energizing relay 201a and also its self-energization contact 223. After pushbutton 220 has been released, relay 221 remains inoperative and the relay 201a can nolonger be energizedautomatically once more since none of the

contacts

224, 205a, 207a can be closed subsequently. The cycle continues as above-described, but at the end of thefinal opera tionthe relay 201a remains inoperative since its three energizing branches are open. Operation in the automatic mode is thus arrested after the final operation.

An alternative operating mode consists in effecting only one complete cycle. This isobtained by operating manual pushbutton 224, which energizes the relay 201a associatedto thefirst operation. Afterpushbutton 224 has been released, relay 201a remains energized via its self-energizing branch. The first operation consequently takes place and upon completion triggers the second operation. The cycle continues until the ultimate operation. As when automatic operation is halted, relay 201a can no longer be energized and the machine stops automatically at the end of the last operation. A further pressure on pushbutton 224 is required to initiate a new cycle.

A third possible operating mode consists in having the operations performed. one by one by manual initiation. To this end, with the switch 211 closed and all the relays inoperative, selector 201 is :moved from position 209 to position 2090. If the actuators are at the end of their travel after the final cycle operation, relay 201a is energized-and causes signallingof the first operation and activation of actuator 218a. At the end of the first operation, pushrod 203a closes contact 2025, but because

selector contact studs

225 and 20% are separated, relay'20lb remains de-energized and only the first operation is performed. In moving to position 209b, relay 20lb is then energized, causing actuator operation. Thus an operation in .the cycle can be performed by activating the corresponding actuator or actuators through the same electrical components (notably the relays) as the ones which activate these actuators in normal operation. This possibility enables the cycle to be broken down into its separate operations, notably for adjustments. Further, this operation-byoperationfunctioning mode permits rapid fault location. Forinstance, if the machine should stop accidentally during an operation while in the automatic operation mode, all that is necessary is to close switch 213 in orderto identifythe operation during which the machine has stopped, to cut off the power by opening master switch 211 thereby rendering all the electrical components inoperative, repair the fault (e.g.- a relay, an actuator or contact) place selector 210 in the" position corresponding to the identical operation, re-connect the power supply by closing. switch: 211 thereby energizing the relay corresponding to *theoperation and completing the latter, andfinally complete the cycle operation by operation; The machine can then be operated in the desired mode;

It may happen in some cases that at least two operations in the cycle are identical and involve the same mechanical components. These components common to both operations then operate two limit switches connected respectively into the relay circuits associated to those operations.

With regards to the actuators 21'8" electrically controlled by the relays201, they maybe of any conve nient type but preferably devised in the" form of electri= cally operated valves'for controlling the mechanical actuators which perform the"fashioning operation.

The electrical control and signalling system described hereinbefore isapplicableto any automatic machine whose cycle consists of. several operations. The

limit switches 202 will accordingly be closed in succestures such as those used for filters in the motor industry, since such machines involve complex fashioning cycles whose operations must be performed in a clearly defined order and at a very rapid rate. Further, because such structures are relatively fragile it is important to stop the machine if the structure breaks and to resume the cycle from the end of the previous operation onwards. in such cases, the automatic, semi-automatic and manual operating modes offer a definite advantage.

Thereby, and irrespective of the form of embodiment adopted, it is possible to devise an electrical control and signalling circuit, a description and the manner of operation and utilization of which have been indicated hereinbefore and which offers various advantages, including the following:

long life, having regard for the large number of operations, made possible by the use of relays;

reliability, since no operation can be performed unless the previous one has been completed;

a wide range of utilization possibilities, stemming from the three operating modes;

universal application to any automatic machine.

What is claimed is:

1. A machine for fashioning structures from flexible products, and more particularly an automatic machine with an operating cycle comprising several operations for fashioning developable pleated chevron-pattern structures from at least one paper-band, including first means for scoring longitudinal fold lines on the band transversely spaced by the width of a half-chevron and for initiating folds about these lines to obtain the chevron pattern, said means being devised to drive the band towards the exit end of the machine; second means for producing transverse folding lines whereby to form the folds half-fold by half-fold and accentuate the chevrons on each half-fold; third means for imparting their final shape to the chevrons, which third means are formed by convergent differentially moving rakes directed substantially longitudinally; and fourth means for moving the fashioned structures out of the machine.

2. A machine according to claim 1 in which said first means are forming longitudinal fold lines on the band and initiating-a folding therealong, consist of a first pair of rollers formed with matching ridges and grooves with an interval therebetween on each roller equal to the width of a half-chevron and of other-pairs of rollers the surface of which is formed by symmetrical frustoconical portions coaxial with said rollers and of length measured along the generatrix equal to said interval, said frusto-conical portions being increasingly greater in number on said rollers in the sense of travel of the bands through the machine.

3. A machine according to claim 2 in which at least one pair of rollers embodies a freewheel device and is rockable for the purpose of driving the band.

4. A machine according to claim 2 in which said means, for obtaining transverse folding lines whereby to form folds half-fold by half-fold and accentuate the chevrons on each half-fold, consist of two independent spade-like members rocking alternately about transverse axes and each adapted to apply the bands against the other rocking spade, and of non-rocking thrust spades, all the said spades having a profile corresponding substantially to that of the rollers.

5. A machine according to claim 1 in which said third means, for imparting their final shape to said chevrons,

means are convergent differentially moving rakes arranged in two series positioned one above and the other below the bands, each rake in oneseries alternating with a rake in the other series. 6. A machine according to claim 5, in which one part of the rakes in each series thereof is devised to drive the bands towards the output end of the machine by bearing against chevron-pattern lines and the other part of the rakes is devised to restrain the bands by bearing against chevron-pattern lines.

7. A machine according to claim 1, in which mechanical members of the meansfor forming the folds and chevrons are actuated by fluid-operated jacks.

8. A machine according to claim 7, in which said mechanical members are actuated from a common camshaft which drives pushrod members each connected to a member to be actuated.

9. A machine according to claim 7, in which said mechanical members are directly actuated from independent cam-boxes to which a uniform rotational motion is imparted through flexible transmission means.

10. A machine according to claim 1, comprising a feed system enabling it to operate in an intermittent cycle for fashioning structures under low and constant tension from at least one feedstock unit delivered by an associated unwinding element, including;

a driving member for said unwinding element,

a coupling betweensaid driving member and said unwinding element,

means for controlling said coupling according to the quantity of feedstock already delivered by said unwinding element but not yet absorbed by the machine, said last-named means consisting of a pulley over which the feedstock unit runs before being absorbed by the machine and the axle of which is movable to operate contacts for controlling. said coupling; and

conveyor means synchronized with first fashioning tools of the machine, which also draw in the feedstock, said conveyor means being located between the means for controlling the coupling and said first tools.

11. A machine according to claim 10 comprising a feed system for fashioning structures from at least one feedstock unit and a supporting tape adapted to facilitate the driving and fashioning of said unit, in which:

each feedstock unit and the supporting tape are supplied to the machine by individual said feed systems, the conveyor means of the feed systems being common to all the systems; means for regulating the tension in the supporting tape provided at the output end of the machine.

12. A machine according to claim 11, in which the means for regulating thetension in-the supporting tape are formed by a pulley-block.

13. A machine according to claim 10, in which the conveyor means synchronized with said first tools of the machine are formed by two rollers supported for freewheel motion on a rocking arm and between which extends the feedstock unit of the composite formed by the feedstock units and the supporting tape, said rollers being prevented from rotating in the direction tending to drive said units towards the .input end of the machine.

14. A machine according to claim 10, in which the driving member for the unwinding elements is a pulley continuously rotated by an auxiliary motor.

15. A machine according to claim comprising control means of the couplings positioned between the driving members and the unwinding elements and formed by a pulley having its axle movable whereby to operate control contacts, characterized bythe fact that the pulley, when in one position, causes rotation of the unwinding element and, when in another position, ar-

rests said rotation.

16. A machine according to claim 15, in which when in one limit position, the pulley causes complete stoppage of the machine fed by the system.

17. A machine according to claim 10, in which the material supplied to the machine by the conveyor means is a laminated sandwich formed by at least two sheets of paper and a supporting tape therebetween.

18.,A machine according to claim 12, in which the supporting tape is endless,'its unwinding element is-a recycling pulley and the regulating pulley-block is positioned between the output end of the machine and the 1 recycling pulley.

19. A machineaccording to claim 1, in which that control and signalling means are provided by associating to each of the operations in the cycle a relay circuit devised so that the relay corresponding to a specific operation controls at once closure of a signalling circuit indicating that the operation has been commanded,

opening of the relay circuit corresponding to the previ-' ous operation, closure of a circuit for preparing the next operation and closure of a circuit for controlling the actuator members that tion.

20. A machine according to claim 12, in which the relay circuits are devised so that operation can take place in automatically repeated'cycles, or cycle by cycle, or operation by operation.

21. A machine according to claim 19, in which each perform the required operarelay circuit comprises in series a relay, at least one limit switch closed by the actuator member that was activated during the previous operation, and two parallelconnected branches the first of which includes in series a first contact that is closed when the relay is energized and a second contact that is opened when the relay of the relay circuit corresponding tothe next operation is energized, and the second of which comprises a contact that is closed whenthe relay of the relay circuit corresponding to the previous operation is energized.

22.'A machine according to claim 21, in which the second branch of the relay circuit associated to the first operation includes, in series with the contact of that branch, a second normally-closed contact that is opened when the relay assigned "to the next operation is energized.

23. A machine according to claim 19, in which the relay circuits are parallel-connected.

24. A machine according to claim 20, in which the electrical means'for operation in the automatically repeated cycles mode are formed by a control circuit comprising a relay and a control pushbutton therefor,

contact and cause energization of the relay of a relay circuit, which is the circuit associated to the first operation in the cycle, through closure of the second contact in the second branch. 7

25. A machine according. to claim 20, in which the electrical means for operation in the cycle-bycycle mode are formed by a normally-open pushbutton parallel-connected to the two branches of the relay circuit associated to the first operation in the cycle.

26. A machine according to claim 20, in which the electrical means for operation in operation-byoperation mode are formed by a manual rotary selector adapted to energize successively and in the necessary order that portion of the relay circuits which, for each relay circuit, is formed by the limit switch and the relay.

according to claim 1.

Claims

2. A machine according to claim 1 in which said first means are forming longitudinal fold lines on the band and initiating a folding therealong, consist of a first pair of rollers formed with matching ridges and grooves with an interval therebetween on each roller equal to the width of a half-chevron and of other pairs of rollers the surface of which is formed by symmetrical frusto-conical portions coaxial with said rollers and of length measured along the generatrix equal to said interval, said frusto-conical portions being increasingly greater in number on said rollers in the sense of travel of the bands through the machine.

5. A machine according to claim 1 in which said third means, for imparting their final shape to said chevrons, means are convergent differentially moving rakes arranged in two series positioned one above and the other below the bands, each rake in one series alternating with a rake in the other series.

6. A machine according to claim 5, in which one part of the rakes in each series thereof is devised to drive the bands towards the output end of the machine by bearing against chevron-pattern lines and the other part of the rakes is devised to restrain the bands by bearing against chevron-pattern lines.

7. A machine according to claim 1, in which mechanical members of the means for forming the folds and chevrons are actuated by fluid-operated jacks.

10. A machine according to claim 1, comprising a feed system enabling it to operate in an intermittent cycle for fashioning structures under low and constant tension from at least one feedstock unit delivered by an associated unwinding element, including; a driving member for said unwinding element, a coupling between said driving member and said unwinding element, means for controlling said coupling according to the quantity of feedstock already delivered by said unwinding element but not yet absorbed by the machine, said last-named means consisting of a pulley over which the feedstock unit runs before being absorbed by the machine and the axle of which is movable to operate contacts for controlling said coupling; and conveyor means synchronized with first fashioning tools of the machine, which also draw in the feedstock, said conveyor means being located between the means for controlling the coupling and said first tools.

11. A machine according to claim 10 comprising a feed system for fashioning structures from at least one feedstock unit and a supporting tape adapted to facilitate the driving and fashioning of said unit, in which: each feedstock unit and the supporting tape are supplied to the machine by individual said feed systems, the conveyor means of the feed systems being common to all the systems; means for regulating the tension in the supporting tape provided at the output end of the machine.

12. A machine according to claim 11, in which the means for regulating the tension in the supporting tape are formed by a pulley-block.

13. A machine according to claim 10, in which the conveyor means synchronized with said first tools of the machine are formed by two rollers supported for freewheel motion on a rocking arm and between which extends the feedstock uNit of the composite formed by the feedstock units and the supporting tape, said rollers being prevented from rotating in the direction tending to drive said units towards the input end of the machine.

15. A machine according to claim 10 comprising control means of the couplings positioned between the driving members and the unwinding elements and formed by a pulley having its axle movable whereby to operate control contacts, characterized by the fact that the pulley, when in one position, causes rotation of the unwinding element and, when in another position, arrests said rotation.

18. A machine according to claim 12, in which the supporting tape is endless, its unwinding element is a recycling pulley and the regulating pulley-block is positioned between the output end of the machine and the recycling pulley.

19. A machine according to claim 1, in which that control and signalling means are provided by associating to each of the operations in the cycle a relay circuit devised so that the relay corresponding to a specific operation controls at once closure of a signalling circuit indicating that the operation has been commanded, opening of the relay circuit corresponding to the previous operation, closure of a circuit for preparing the next operation and closure of a circuit for controlling the actuator members that perform the required operation.

20. A machine according to claim 12, in which the relay circuits are devised so that operation can take place in automatically repeated cycles, or cycle by cycle, or operation by operation.

21. A machine according to claim 19, in which each relay circuit comprises in series a relay, at least one limit switch closed by the actuator member that was activated during the previous operation, and two parallel-connected branches the first of which includes in series a first contact that is closed when the relay is energized and a second contact that is opened when the relay of the relay circuit corresponding to the next operation is energized, and the second of which comprises a contact that is closed when the relay of the relay circuit corresponding to the previous operation is energized.

22. A machine according to claim 21, in which the second branch of the relay circuit associated to the first operation includes, in series with the contact of that branch, a second normally-closed contact that is opened when the relay assigned to the next operation is energized.

24. A machine according to claim 20, in which the electrical means for operation in the automatically repeated cycles mode are formed by a control circuit comprising a relay and a control pushbutton therefor, which relay is adapted to activate its self-energizing contact and cause energization of the relay of a relay circuit, which is the circuit associated to the first operation in the cycle, through closure of the second contact in the second branch.

25. A machine according to claim 20, in which the electrical means for operation in the cycle-by-cycle mode are formed by a normally-open pushbutton parallel-connected to the two branches of the relay circuit associated to the first operation in the cycle.

26. A machine according to claim 20, in which the electrical means for operation in operation-by-operation mode are formed by a manual rotary selector adapted to energize successively and in the necessary order that portion of the relay circuits which, for each relay circuiT, is formed by the limit switch and the relay.

27. A machine according to claim 24, in which a normally-closed contact series-connected to the contact of the second branch can be opened when the relay of the relay circuit corresponding to the next operation is energized.

28. Developable pleated chevron-pattern structures, and more particularly filter elements for automobile applications, fashioned from paper bands by a machine according to claim 1.