US1884468A - Method of and apparatus for the manufacture of flat bags and envelopes - Google Patents

Description

at 25 1932 A. WENKLER ET AL.

METHOD OF AND APPARATUS FOR THE MANUFACTURE OF FLAT BAGS AND ENVELOPES Filed July 12, 1929 2 Sheets-Sheet l Jnveniors. fllfred h znkler' I Y and Ma pdnnebzen @ch 25, R932. A. WINKLER ET AL 1,884,468

METHOD OF AND APPARATUS FOR THE MANUFACTURE OF FLAT BAGS AND ENVELOPES Filed July 12, 192? 2 Sheets-Sheet 2 Patented Oct. 25, 1932 amrrao s'mrasv PA ENT OFFICE ALFRED WINKLER AND MAX Dtl'NNEBIEB BALTIMORE PAPER MISSOURI onnnuwrnn, ennmm, assrsnons 'ro oomraur, or KANSAS CITY, mssonaz, a coaroaarron' or METHOD OF AND AEPABATUS FOR THE MANUFACTURE OF FLAT BAGS AND ENVELOPES Application filed July 12, 1929, Serial No. 377,779, and in Germany July 13, 1928.

The high eificiency of enveloping-making machines which work from the punched or cut out blank according to the cylinder-folding system is not attained by any of the flatbag machines hitherto known, nor has it heretofore been possible to employ cylinder envelope-folding machines also for the manufacture of fiat bags by means of a mere change of adjustment and without time-consuming interchange of essential parts, although in view of their efliciency and their other advantages,-the principal one of which is their rapid and simple adjustability from one size to another, this seemed very desirable, the more so since fiat bags particularly find employment, as articles handled in large quantities, for the most varied purposes to an extent even greater than envelopes It should be understood that by the term bags or flat-bags as used above and in the following description the article referred to is a flat paper or like bag or envelope of the well-known type in which the bottom flap is of short or narrow form and in which the side flaps are gummed to each other centrally of the article or to one side thereof, as distinct from the usual form of envelope in which the side-flaps are connected together solely by reason of their attachment to the comparatively deep bottom flap which is gummed over the two folded but unattached side-flaps.

This invention relates in the first place to a method of manufacturing flat bags with side or central gumming, by means of which and in consequence of its novel sequence of c operations the high-efficiency cylinder en velop'e-folding machines of the well-known type are made applicable for the optional manufacture of envelopes or flat bags. Further objects of this invention are the provision of improved means and arrangements for such optional manufacture of envelopes and flat paper bags.

In the process of manufacture that is cus tomary, in the,case of envelopes, with the employment of cylinder folding-machines, the sequence of the operations is as follows: 1) drawing-in of the individual sheet or blank from the stack in a direction parallel operation was not possible in the manufacture of flat bags on machines by means of which envelopes were also manufactured, because in the latter the conveyor and other devices and their distances apart were not adapted to the great differences in length in the individual sizes of bags and because, above all, the short lengths of the bottom flap and the closure flap in the case of bags did notv admit of uninterrupted conveyance through the machine.

The method according to the present invention is characterized b the fact that the bag cut-out or blank that is withdrawn from the stack is drawn into the machine in its full length in" the'direction of the folds of the bottom flap and the closure flap, whereupon, after the blank has been straightened out, the following operations are performed in succession: (1 creasing of the two longitudinal or side olds, (2) foldin over and creasing of the bottom flap and c osure flap, (3) reopenin of the two latter flaps, (4) a plication oft e gum to the narrow lon itud nal fia and to the bottom fla (5 olding over 0 the wide side flap, (6) fol ing over of the narrow side flap and erformance of the longitudinal gumming, (7 closing of the bottom and closure flaps and performance of the bottom gummin This se uence of operations alone afior s the possi ility of employing, for the manufacture of bags cylinder folding machines which at the same flap and closure flap must be folded over at that point at which in the case of envelopes the folding-over of the side flaps takes place, and vice versa in the case of bags the side flaps are folded at that point of the machine at which the folding of the bottom flaps and closure flaps is performed in the case of envelopes. In the case of bags, accordingly, although these require the reverse sequence, the bottom flap and closure flap are folded before the side flap because of the limitation to the arrangement of the devices within the machine, as it is required for the manufacture of envelopes.

These difficulties are overcome in accordance with the present invention by the. alteration of the existing means and by the provision of new contrivances; in that connection precautions have been taken to ensure that the alterations made shall not be obstructive in the preparation of envelopes and that the special contrivances may easily and rapidly be removed or thrown out of operation.

In the drawings there is illustrated by way of example a cylinder folding machine which is in its essentials well-known for the manu facture of envelopes and which, for carrying out the method according to the present invention, is equipped with the alterations and ipecial contrivances for the manufacture of ig. 1 is a side diagram of the machine;

Fig. 2 is a representation of the different stages in the manufacture of flat bags accordin to the method of this invention, the indivi ual stages of operation being drawn in vertical projection under those points of the machine at which they are reached within the latter;

Fig. 3 shows, in vertical longitudinal section, the means for the separation of the sheet from the stack and for its drawing into the machine;

Fig. 4 shows the suction device in front view;

Fig. 5 shows the suction device looking from above;

a Fig. 6 is a sectional view of the means for controlling the suction;

Fig. 7 shows the same in transverse section;

Fig. 8 shows the means for the straighteningrof the sheet; 1

i 8a shows the positions of the sheet relatively to the means of Fig. 8;

Fi 9 is a plan view showing the means for t e reopening of the bottom flap and closure flap after their folding;

Fi 10 is a side view partly in section showing the means for the formation of the lon itudinal folds of the bag;

ig. 11 shows the upper cylinder serving in the forming of the first longitudinal fold,

seen' in the direction of the arrow in Fig. 10; Fig. 12 is a longitudinal section of the lower cylinder for the formation of the two longitudinal folds of the bag, together with its head-piece;

Fig. 13 shows the cylinder-engaging face of the said head-piece;

Fig. 14 is a side view of the means for the anal closing of the bottom flap and closure Fig. 15 shows the pressure rollers for the bottom flap and closure flap, looking in the direction of the path of the work-piece; and,

Fig. 16 shows the same rollers in side view.

The machine, together with its modifications and special means'for the manufacture of bags is hereinafter described in the sequence of the operating process, from the drawing-in of the blank to the delivery of the completed bag.

In the stack 1 the blanks or cut-outs are so arranged that the edge of the wide side fold S (Fig. 2) is situated toward the machine, i. e., in the drawing toward the right, and the closure flap V toward the beholder. The suction device 2, whose angular movement is indicated. in broken lines, (in Fig. 3) seizes by suction the lowermost blank in the stack 1 and bends it down against the cylinder (1. With the cylinder at there cooperates a pair of aligned rollers a arranged above it and on both sides of the suction device 2. Each of these rollers a carries an elastic draw-in finger 3 rotatable about its own axis. Between the fingers 3 space is left for the passage of the suction device 2. When the latter has bent the blank down into the position shown in broken lines (at Fig. 3) the suction ceases and the blank is stripped from the suction device by the drawing in fingers 3 and is laid upon the cylinder a. This stripping of the blank from the suction device presents difiiculties in case of the employment of the form of suction device ordinarily employed for envelopes where the triangular bottom flap is seized only at its point by the suction device and to avoid these difiiculties the suction device is provided with a fluting which extends "in the direction of the path of the blank, so

that in the process of drawing by suction, there is formed between the lowest blank and the one above it (even while the suction dev ce is still in contact with the stack) a small recess which corresponds to the fluting of the suction device, and into this recess in well known fashion a swinging tongue 24 (Fig. 3) is introduced for the support of the stack before the suction device moves downward with the blank that has been drawn by suction. Shortly before the suction device is applied to the next blank, this tongue 24 is swung out of the operative position. In case of the preparation of flat bags the suction device must be of substantial width,and if this device were made with a fiuting of the type above-mentioned, the front edge of the blank, in consequence of its length, would be bent upwards at both sides of the suction device and would have a curvature extending to wards the rear so that the stripping off from the suction device by the draw-in fingers 3 would be resisted by the stiffened blank and the front edge of the blank would be wrinkled or torn. In order to remedy this drawback, the suction device 2 is given, in accordance with this invention, two intersecting fiutings with the axis of the one extending in the direction of the path of the blank and the axis of the other perpendicular thereto, i. e., parallel to the front edge of the blank piece; and furthermore the suction apertures in the -suction device are so arranged that one or more 7 of them are situated at the lowest point of the first-mentioned fluting, namely as far as possible in the direction of the edge of the blank, and the otherson both sides thereof at the lowest point of the other fluting which extends parallel to the edge of the blank. Figs.

3 and 4 show the effect of th s expedient whereby the fluting which extends parallel to the edge of the blank creates a curvature of the sheet which extends along the edge of the blank and corresponds to the natural bending of the sheet in its being stripped from the suction device, which curvature prevents such a curvatureof the sheet as has a stiffening ac tion, while the fiuting produces at the same time. in the direction of the path of the blank. in consequence of the higher-situated central ,suetion aperture 25, in the middle of the edge of the cut-out piece, a recess suliicient for entry of the swinging tongue 24 between the blank drawn by suction and the one just above it.

In order,- in the manufacture of bags to impart the described shape, by means of the suction device, to the wide sheet that is to be drawn away by suction, particularly also in the case of thick papers, and in order to attain the bending away of the sheet with certainty, not only is it necessary to have a powerful suction effect, but this effect must set in suddenly with its full power at the moment when the suction device is applied against the lowest blank, and must remain fully in action until the end of the blank has been bent down so far that it can be seized by the draw-in fingers 3 (Fig. This purpose is served by the following arrangement.

The hollow shaft 26 (Figs. 6 and 7), to which the swinging suction device 2 is attached, has mounted thereon a sleeve 27 which fits closely on the shaft 26; and fitting closely upon the sleeve 27 is a junction piece 28 which effects the connection through the bore 29 with the suction piping leading to the pump.

The bore 29 in the junction piece 28 com-' I municates with a groove 30 which extends in an axial direction. In the sleeve 27 there is provided an aperture 31, of the length of the groove 30 in the junction piece 28 and at the same point as the latter, which aperture exprojects on one side beyond the junction piece 28 and there carries a sprocket wheel 33 that is firmly connected with it. On this side the sleeve 27 is secured against longitudinal displacement on the shaft 261by means of a collar 35, and the junction piece 28 is thus secured on the sleeve 27 by means of the sprocket wheel 33. On the opposite side the sleeve 27 and the junction piece 28 bear against the machine frame 34. The sleeve 27 is driven by means of the sprocket wheel 33 in such manner that it makes one revolution for every blank fed to the machine. In consequence thereof, in case of correct mutual adjustment of the shaft 26, the sleeve 27, and the junction piece 28 and in case of suitable width of the sleeve aperture 31, the result is that at the moment at which the suction has to begin, the aperture 31 suddenly effects in its full cross-section the connection between the pipe-end bore 29 and the slit 32 in the suction-device shaft 26 and interrupts it again with equal rapidity at precisely the ;ter commences to execute a partial revolution,

so that the sheet, which is grasped between the draw-in fingers and the roller, is withdrawn from beneath the stack to the extent of this partial revolution, in which process it gets under the pair of rollers a. In this manner the sheets are arranged in echelon or overlapping relation one above the other in conformity with Fig. 2, I and are formed into a row which travels step-by-step to the pair of rollers 6-6, which run continuously, but with corresponding rate of speed, and from the latter at uniform speed to the rapidly running pair of rollers c0, by which the foremost blank is seized and entirely withdrawn from the row of blanks and is then conveyed forward alone on its further course and may thus be subjected to the further individual operations, each successive blank being thus separated from the row and being conveyed 1 forward. The first of the said individual operation consists in the straightening of the blank, for which purpose the means shown in Fig. 8 is provided.

Between the last-named pair of cylinders cc and the succeeding pair dd' there are provided two pairs of straightening fingers, a front pair 4 and a rear pair 5. Both are adapted to swing in such a way that they locate themselves in the path of the blank and withdraw from it again. The straightening of the blank is effected in well-known manner by this means; the straightening fingers placing themselves into the re-entrant corners of the blank and, in so doing, correct any irregularities in position of the blank. For the purpose of adaptation to the individual sizes, the rear pair of straightening fingers 5 is displaceable in the direction of the path of the blank and is capable of being set, and so also, in like-manner, is the pair of cylinders 00. The'mode of operation of the entire straightening stage is wellknown per se and is briefly as follows: I

The pair of cylinders 00' is adjusted in such a way that it conveys those re-entrant corners of the blank that are situated toward the front in the direction of the motion to within a very short distance of the front straightening fingers 4 which have been swung into its path. At the moment at which the blank has reached this position, the rear straightening fingers 5 reach into its rear re-entrant corners and push it ahead such a distance that all four fingers are situated exactly in the-four re-entrant corners of the blank, by which process the straightening-out has been effected. Thereupon all four of the straightening fingers are swung back and the blank is thereby released. At the same moment the flap 38, which is built into a longitudinal recess in the cylinder d (and which may be moved by means of an adjust-able cam disk 37 so as to coincide with or lie within the periphery of the cylinder) grips the sheet and thus delivers it to the periphery of the cylinder, which cylinder d has two adjustable creasing knives for the creasing of the bottom fold and the closureflap fold in the case of envelopes and of the side-flap folds in the case of bags. For the purpose of this creasing the counter-cylinder d has a rubber coating. In the manufacture of bags, particularly in the case of those with lateral gluing, it is impossible within this straightening stage, in consequence of the narrow side flap S, to convey the blank through the pair of cylinders 0-0 as far as a short distance in front of the front straightening pair 4, because the cylinders cc' cannot be placedclose enough to the rear pair of straightening fingers 5. For this reason, in the preparation of bags, the pair of cylinders cc is set in such a way that the leading side flap S of the blank is pushed so far be tween the pair of cylinders (Zd that, se zed by a segment 36 w ich, according to this invent-ion, is specially built into the cylinder (1, it is conveyed ahead by this segment a distance which is equal in the case of all sizes and which suffices to bring the front reentrant corners of the blank within a Very short distance of the front pair of straightening fingers 4, as is done directly by the pair of cylinders 0-0 in the case of the manufacture'of envelopes. From this point onwards the rear pair of straightening fingers 5 takes over, in this case also, the further conveyance for the purpose of straightening, and now there results, as above described, the creasing of the side-flap fold by the cylinder (1, after the latters flap 38 has come into action in the manner that has likewise been described.

On its further course the blank then gets between the pair of cylinders ee, which feeds it to a device, which is well-known per se, for the folding over of the bottom flap B and closure flap V, in which device the two flaps are bent upward by so-called lifters 9 around adjustable bladelike folding-bars 8 and are folded over by slides 10. This folding over of the bottom flap B and the closure flap V, generally speaking, takes place too soon in the case of bag blanks, because these two flaps must come to lie upon the side flaps, which, however, in consequence of the adaptation of the machine to the manufacture of envelopes are not yet folded over; nevertheless the folding over of the bottom flap and closure flap is erformed, firstly in order to utilize the devices which are already available in the machine and secondly because of the fact that the performing of this work only after the folding of the side flap has taken place would have to take place under more unfavorable circumstances, as will be apparent below. According to the present invention, therefore, the bottom flap and closure flap, after they have been folded over by the above-mentioned devices and have been pressed between the cylinder 7 and its adjustable counter-rollers f, are immediately folded back again. For this purpose there is provided beyond the cylinder f and its counter-rollers f, an adjustable pair of curving fold guides 40 (Fig. 9). Each of these guides 40, of which only that at the one side of the blank is shown in the drawings, immediately adjoins the bladelike foldingbars 8, and the pressing rollers f, which are indicated in broken lines at Fig. 9, are adjusted so close above the folds that the folding back of the flaps may even be commenced during the pressing process. The curving fold guides 40 are expediently attached to the bearing-arms of the adjustable counter-rollers g of the intermediate cylinder g, because in consequence thereof, at the adjustment of the intermediate rollers g to a particular size, the'adjusting of the curving fold guides 40 is also effected simultaneously. The construction of the curving fold guides 40 is well-known per se; they are situated at the entering "side of the blanks under the flaps, and the slope of their upper surface increases more and more in the direction of the path of the blank in such a way that by the end of the loop it turns to the extent of 180 and that the flaps, which follow the course of the helical shape, are again folded back completely into the plane of the sheet.

For the application of gum, which takes place simultaneously forthe gumming of the bottom and for the longitudinal gumming, means are provided which are employed also in the manufacture of envelopes, and which consist of the gum container 45, the gumdipping c linder 46, the gum ap lication cylinder 47 and the gummers 11 w ich are interchan eable on their shaft. The upper cylinder of the pair of cylinders hh which takes over the blank after the application of gum has taken place also consists, as in the manufacture of envelopes, of cylinder portions, adjustable transversely to the path of the blank, with recesses in their periphery in order to prevent smearing of the gum. For the turning up of the leading side flap S on its creasing we employ the same swingable folding-elbow 14 as serves for the turning upward of the bottom flap in the case of envelopes.

The following pair of cylinders z'z', to which the closing and pressing of the bottom flap are assigned in the manufacture of envelopes, has, in the case of bag blanks to attend solely to the closing of the first side-flap fold. In this operation a swinging folding-blade 15 aids, in the well-known manner, the proper entrance of the previously made crease between the pair of cylinders. The upper cylinder 6, in view of the exposed gum still lying upward for the bottom gumming 12 and the longitudinal gumming 13 as indicated in cross-hatching in Fig. 2, VII requires special means for the manufacture of bags. In the first place the application of gum on the bottom flap necessitates the employment of only a narrow cross-bar 48 (Figs. 10 and 11) for the creasing of the folds of the first transverse folding which takes place between this upper cylinder 71 and its lower cylinder 71. This cross-bar 48 must not reach further over the fold than is indicated in Fig. 2, VI by the dot-and-dash line, since otherwise a smearing of the gum on the bottom flap would result. F urthermorc, for the same reason the conveyance by the upper cyl1nder I must not go further than a short distance in frontof the inner edge of the longitudinal gumming 13 on the still open side flap S. The distance that the conveyin is to cover is accordingly different accordlng to the size of bag that is to be prepared at any particular time, and therefore the upper cylinder 2" is composed of mutually ad ustable segments in such away that two inner fixed segments 49 directly take over, in the case of all sizes, the conveyance that has been effected by the rail 48, while the conveyance is turned over by these to two additional segments 50 which can be turned on the shaft 51 and there- -the case of bags,

by be correspondingly adjusted to the length of conveyance that is possible at any particular time, and can also be displaced laterally in adaptation to the length of the bag.

The two outer segments 50 accordingly convey the blank in conjunction with the lower cylinder 2' as far as a short distance in front of the inner edge of the longitudinal gumming 13; since, however, the'conveyance must proceed without interruption, there is a need at this point also, in the manufacture of bags, of special means which are furthermore also necessitated by the shortness of the trailing side flap S in the case of be s having lateral gumming. To begin wit it may be mentioned that in the case of cylinder folding-machines of the type here in question, as they have in' particular come to be known in their essentlals from German Patent 349,878, (United States Patent No. 1,376,906, November 15, 1921) the blank undergoes a reversal of its direction of motion beyond the pair of cylinders ic", in that a piece of sheet metal which can be raised and lowered, the so-called shut-off 16, blocks its path when it comes out of the cylinders 11- 5. It is thus placed upright against this shutoff 16 until the second longitudinal fold in the case of bags or the closure fla -fold in the case of envelopes has left the cy inder M; then the shut-off 16 moves upward and clears the ath to the second upper cylinder '5"- whic cooperates with the cylinder 6 and is displaced to the extent of about 60. Under this upper cylinder 2'" the second side flap S receives its folding in the case of bags, the closure flap in the case of envelopes. Here again a folding-blade 17 assures the correct entrance of the creased fold between the cylinders 4-1". The conveyance of this second fold to the upper cylinder z'" must accordingly be effected with the said of the trailing flap, which alone is still situated under the cylinder Z-Z', a procedure which is indeed possible in the case of envelopes, but not in yiarticularly those having lateral gumming, ecause in that case the trailing side flap is too short. In accordance with the invention this difficulty is overcome by this means that the cylinder 2' is constructed as a suction cylinder, which acts in such manner, that it grips the gummed side flap S of the bag by suction even at its passa e between the cylinders 75-4" shortly before its conveyance by the segments 50 of the c linder i ceases. The suction persists unti the second longitudinal fold has been received under the cylinder 71''. Figs. 10, 12, and 13 show the construction of the suction cylinder a. It has in its interior a suction channel 52 which extends in the direction of its length and from which several suction apertures 52', arranged in a row, lead to the outer surface of the cylinder. The suction channel 52 is open on one end face of the cylinder, and

against this end face of the cylinder a stationary head-piece 53 is closely applied. This heap-piece 53 has in its interior acompletely encircling annular channel 55 for the conveyance of the suction air together with a segment-like suction aperture 56 which is located in the direction of the cylinder and is so situated that at the rotation of the cylinder '5 the termination of its suction channel" 52 comes to coincide with the aperture 56 of the headpiece 53. By means of a short pipe section 54. the annular channel 55 is connected to the suction piping of a rotating airpump. The adjustment of the headpiece 53 and the delimitation of its aperture 56 are effected in such a way that the suction channel 52 of the cylinder 2' arrives over the aperture 56 of the headpiece 53 at that moment when the suction has to commence and leaves it again when the suction effect is to cease. B means of this contrivance a conveyance of the second longitudinal fold from the cylinder 2" as far as the cylinder 2' is attained with certainty even in the case of bags having very short side flaps.

At the assage of the work-piece between the cylin ers i-", in which connection the gum application device 12 of the still unfolded bottom flap B is situated in the direction of the cylinder 2', precautions must be taken to prevent a smearing of the gum on this cylinder. On one portion of its periphery, where the bottom flap B runs past, it therefore has a recess 57 which is dimensioned according to the largest size of bag that is handled and which is indicated in Fig. 10 by the broken line that extends concentrically with the line of the periphery of the cut-out piece.

Whereas envelopes leave the pair of cylinders ci in an already completed state and may be conducted to the delivery stack, it is necessary in the case of bag blanks that beyond this pair of cylinders the bottom flap B and closure flap V, which flaps were, for the reasons stated above, opened again after the first folding, shall be folded over finally and the former gummed in the process. The path from the cylinders z'i as far as the delivery stack 23 is therefore, according to the invention, so arranged that in the manufacture of bags it is possible to perform upon it the final folding over of the bottom flap and closure flap and the gumming of the former, while it can be traversed without further operations by the completed envelopes. For this purpose the well-known conveyor wheels 20, which push the completed bags to the stack by means of cams 22, attached to them, upon tracks 21 laid around them; are so far distant from the pair of cylinders i- 2" that from the latter to them a slanting travel path is roduced. This is formed by four cylinders l, m, and n, which extend clear through, and their adjustable counter-rollers k, Z, m, and n. In the manufacture of envelopes these convey the completed goods directly to the conveyor wheels 20 and their counter-rollers 20 as soon as it has left these, it rests loosely between the conveyor wheels 20. and the curved guides 21 extending around them, Where it is seized by the cams 22 of the conveyor wheels 20 and pushed to the delivery stack 23. For the manufacture of flat bags,

would be unfavorable because of the poor visibility, if the folds were not already prepared in advance; but since such is the case in the course of operations above described, simple folding-bars 18 and curving fold guides 19 of well-known construction and similar to those which were employed for the folding back of the two flaps are sufiicient for this operation. In this connection the arrangement is such that on each side the curving fold guide 19 is adjustably fastened by means of a bar 58 to the bar 58 of the folding-rail 18 so that after a mutual adjustment of the two has once been made, the adjustment of both may be changed jointly in case of change of the size or the thickness'of the paper, namely the adjustment of the height by means of a shifting of the bar 58 in the cross-piece 59 and the transverse adjustment by a shifting of the cross-piece 59 on the attachment rail 60. After the departure from this folding-back device, there occurs between the cylinder n' and its counter-rollers n the renewed pressing of the fold into contact and the gumming of the bottom flap.

The counter-rollers n for the pressing of the fold and for the gumming of the bottom flap must likewise be given a special form of construction in the case of the manufacture of bags. Whereas in the manufacture of envelopes these rollers are traversed by the completed envelopes namely in such a way that the fold edge of the closure flap which lies uppermost runs up against the rollers and that t e side flaps are furthermore secured agains displacement by the gummin of the bottom flap, in the case of bags the folli edges of the loose closure flap and the bottom flap which is folded over, but not yet finally glued, impinge vertically against the rollers n and in consequence thereof, in case of the employment of ordinary cylindrical rollers, displacements of the flaps resulting in the production of double folds might easily occur. This danger is present all the more since, with a view to the gumming of the bottom flap that is to be performed, the rollers n must not be firmly in contact with their counter-cylinder n, but must rather, in conformity with the thickness of the paper, be placed a slight distance away from the latter. Consequently they must receive from each arriving workpiece a new impetus to rotation, but at least be brought again to their proper speed of rotation. The impact that occurs in this process aids the above-mentioned detrimental effect with respect to the displacement of the flaps and the production of double folds. Accord-. ing to this invention there are employed instead of ordinary cylindrical rollers, rollers which have a narrow cylindrical running-surface 51; adjacent to this they have a slightly conical portion 62 and next to this again a cylindrical portion 63 (Fi s. 15 and 16). The cylindrical runnin -surface 51 rests permanently upon the counter-cylinder n, and the rollers n are so adjusted that the fold edges of the bottom flap and closure flop, according to the thickness of the paper in each case, project more or less into the conical portion 62, for which circumstance the amount of the pressure necessary in the cylindrical portion 63 for the gumming is determinative. Grooves 64 which extend circumferentially and longitudinally in the latter prevent a displacement and squeezing-out of the gum at the pressing into contact of the bottom fiapby means of the roller 72 of theside in question of the blank.

The now completed bag runs, in the same Way as the envelope, in well-known manner between the conveyor wheels 20 and their counter-rollers 20, by which it is introduced into the space 65 between the conveyor wheels 20 and the curved guides 21 which are located around them. Here one of the three pairs of cams 22 which are attached to the conveyor wheels 20 seize it at its rear edge and push it through the space 65 until its rear edge has reached the level of the delivery table 66. Atthis moment it is pushed away from the pair of cams 22 by a swinging arm 67 or some other device and is laid against the rear surface of a second pair of conveyor wheels 68, of wellknown construction, which have a wormlike action and which add it, as the last piece at any particular time, to the delivery stack 23.

The rapid conversion of the machine from the manufacture of envelopes to the manufacture of bags or vice versa is ensured from the fact that a great part of the mechanism provided for the production of bags may be retained without modification also for envelopes. These are: the rotatin suction valve .27, the segment 36 of the cylin er (1, the construction of the cylinder 2" with the cross-bar 48 and the segments 49 and 50, and that of the cylinder 2' as a suction cylinder. Accordingly all that remains is the changing of the suction device 2 and the throwing into or out of operation of the folding mechanism, viz: 40 for the reopening of the folded-over and pressed bottom flap and closure flap in the case of bags. and of the mechanism 18, 19 for the final closing of these flaps, as well as, finally, the changing of the gummers 11. These alterations, to which there must further be added only the simple adjustment opera tions-universally necessary also in case the type of blank remains the same-for the transition from one size to another, impart to the machine that unrestricted high efiiciency for the manufacture of bags by which it is characterized to a noteworthy extent in its employment for the manufacture of envelopes.

We claim:

1. A method for the manufacture of fiat bags or other similar articles of the character described, which comprises moving the blank in a direction parallel to the bottom fold and to the closure-flap fold, then creasing the two side folds, then while conveying the blanks folding over, and re-opening the bottom flap and closure-flap, then applying the gum to the bottom flap and one side flap, then folding and gumming the side flaps, and finally refolding and gumming the bottom flap and re-folding the closure flap.

2; A method for the manufacture of flat bags, which comprises moving the blank in a direction parallel to the bottom fold and to the closure-flap fold, then straightening the blank, then creasing the two side folds, then folding over, pressing and subsequently rel-opening the bottom flap and, closure-flap,

then applying the gum to the bottom flap and one side flap, then folding and gumming the side flaps, and finally refolding and gumming the bottom flap and re-folding the closure flap.

3. A method for the manufacture of flat bags, which comprises drawing the blank from a stack, in a direction parallel to the bottom fold and to the closure-flap fold, then straightening the blank, then creasing the two side folds, then folding over, pressing and subsequently re-opening the bottom flap and the closure-flap, then applying gum to the bottom flap and to one side flap, then folding and gumming the side flaps and reversing the blank, re-folding and gumming the bottom flap, then re-folding the closure flap, and finally delivering the completed bag.

4. A cylinder folding-machine for the selective manufacture of envelopes or flat bags comprising elements which serve to form the side folds in the case of bags and to form the folds of the bottom and closure flaps in the case of envelopes, and means for the adjustment of saidelements to change from one class of goods to the other.

5. A cylinder folding-machine for the selective manufacture of envelopes or flat bags comprising rotary creasing means which serve to crease the side folds in the case of bags and to crease the folds of the bottom flap and the closure flap in the case of envelopes, and adjusting mechanism for adapting said means to suit either class of goods.

6. A cylinder folding-machine for the se-- lective manufacture of envelopes or flat bags,

comprising means for forming the bottom flap and closure-flap in the case of bags and which serve to form the side flaps in the case ,in the case of bags and the bottom and closure flaps in the case of envelopes, means for forming the bottom flap and closure-flap in the case of bags and the side flaps in the case of envelopes, means for the application of gum to the bottom flap and to one of the side flaps in the case of bags, and to the bottom flap only in the case of envelopes, and variable means for the adjustment of the machine to suit one or other of said goods.

8. A cylinder folding-machine for the manufacture of flat bags, comprising a suction device for the separation of the lowest blank from a stack, a suction surface in such device, two fiutings of arcuate cross-section intersecting each other at right-angles in said surface, and a separate suction opening in each fiuting, one of which fiutings extends in the direction ofthe path of the blank and the other perpendicular thereto, to cause the blank to bend'in two opposite directions.

9. A cylinder folding-machine for the manufacture of flat bags, comprising a suction device for the separation of the lowest blank from a stack, a suction surface in such device, two flutings intersecting each other in said surface, one of which flutings extends in the direction of the path of the blank and the other substantially perpendicular thereto, suction apertures so distributed in the fiutings that at least one aperture is located, close to the front edge of the blank, in the middle of the fiuting that is situated in the direction of the path of the blank and the others on both sides thereof at the lowest point of the other fluting.

10. A cylinder folding-machine for the selective manufacture of envelopes or flat bags, comprising a suction device for the separation of the lowest blank from the stack, a suction shaft for said device, a junction piece connected with the suction source, a sleeve located between the shaft and the junction piece and moved in unison with the blank, an aperture in said sleeve, a slit in said shaft and a groove in said junction piece, the slit and groove both registering with said aperture to supply suction tothe device.

11. A cylinder folding-machine for the manufacture of flat bags comprising straight ening means for the blank, a rotary member for withdrawing the blank from the straightening means, and means carried by the cylin der to eflect the conveyanceof the blank until engaged by said straightening means.

12. A cylinder folding-machine for the selective manufacture of envelopes or fiat bags comprising straightening fingers for the blank, a cylinder for withdrawing the blank from the straightening lingers, and a segment carried by the cylinder to effect the conveyance of the blank until engaged by said straightening fingers, in the manufacture of bags.

13. A cylinder folding-machine for the manufacture of fiat bags comprising means for the creasing of the bottom flap and closure flap of the bag, and a pair of curving fold guides for reopening the bottom flap and closure-flap.

14. A cylinder folding-machine for the selective manufacture of envelopes or fiat bags comprising pressure means for the creasing of the bottom flap and closure-flap in the manufacture of bags, and a pair of curving fold guides for opening the said bottom flap and closure-flap.

15. A cylinder folding-machine for the selective manufacture of envelopes or fiat bags comprising a cylinder for the creasing of the first longitudinal fold in the case of a bag blank, a longitudinal cross-bar carried by the cylinder and extending the full length thereof for the creasing of said longitudinal fold, and two pairs of segments embodied in said cylinder, one of which pairs is stationary, while the other may be turned on the cylinder axis and displaced in the longitudinal direction of this axis.

16. A cylinder foldinganachine for the manufacture of flat bags comprising two cylinders, a common cylinder cooperating with said cylinders and serving therewith for the performance of the two longitudinal foldings, and suction means embodied in the common cylinder for the forward conveyance of the blank from the first to the second of said two cylinders.

17. A cylinder folding-machine for the manufacture of flat bags comprising a lower cylinder, two upper cylinders serving for the performance of the two longitudinal foldings, and suction means embodied in the lower cylinder for the forward conveyance of the blank from the first upper cylinder to thesecond.

18. A cylinder folding-machine for the selective manufacture of envelopes or flat bags of the character described comprising two adjacent cylinders, a hollow cylinder cooperating with both said cylinders to serve in the case of bag blanks for the performance of the two longitudinal foldings, and suction means embodied in the hollow cylinder for holding the side flap of the blank and ensuring forward conveyance of the blank from one to the other of said adjacent cylinders.

19. A cylinder folding-machine for the selectivemanufacture of envelopes or fiat bags comprising a hollow lower cylinder, two upper cylinders serving in the case of bag blanks for the performance of the two longitudinal foldings, and suction means embodied in the lower cylinder for holding the side flap of the'blank and ensuring forward conveyance of the blank from the first upper cylinder to the second.

20. A cylinder folding-machine for the selective manufacture of envelopes or fiat bagsv comprising finishing means for effecting the final folding in the manufacture of envelopes, conveyor wheels for the delivery of the envelopes, sloping means comprising pairs of rollers located between said finishing means and said wheels, and folding and closing mechanism embodied in said sloping means for closing the bottom flap and closure flap in the case of bag blanks.

21. A cylinder folding-machine for the selective manufacture of envelopes or fiat bags face, an adjacent conical portion on said roller and a second cylindrical portion adjacent to said conical portion and having,

grooves which extend circumferentially and in the longitudinal direction. In testimony whereof we have signed our names to this specification.

ALFRED WINKLER. MAX DUNNEBIER.

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