Method For Applying Cardboard Reinforcements Onto A Paper Web Or The Like

Abstract

Method for gluing reinforcing strips, such as cardboard, onto a web of paper in order to form reinforced handle portions in shopping bags, where a roll of cardboard pulled in by rollers is perforated transversely of the web at predetermined desired distances from one another to form a blank unit with a plurality of blanks which are fed to a segment roller that applies the blanks in spaced relation to glue-bearing areas on a continuously moving web of paper which operates at the same velocity as the segment roller and where any desired number of blanks may be cut and transferred to the web.

Description

BACKGROUND OF THE INVENTION

The invention relates to the manufacture of paper articles, such as paper bags and shopping bags. More in particular, the invention concerns a method and apparatus for applying cardboard reinforcements onto paper sections or blanks on a paper web or the like. This method is of particular significance in the production of shopping bags. It has been found to be advantageous to make the cardboard reinforcements for punching the handles not from a continuous reinforcing paper but to make the reinforcements for hand grips on the web from which the shopping bag is made from individual cardboard cuts which are to be applied onto the web in spaced relationship.

Heretofore it was conventional for such purposes to arrange a suitable number of gluing devices corresponding to the number of cardboard sections to be applied to the web, which then glued the proper number of cardboard sections onto the travelling web. It has been proposed in accordance with German Pat. No. 1,074,961 to provide cutouts at the cutting location of a cardboard web in order to facilitate the tearing. Such a procedure has also been proposed in connection with the scoring lines of shopping bags, i.e., where the hand grip disposition is to be made, but in this case the still remaining cardboard pieces are so stiff that it is not possible to insure satisfactory folding.

SUMMARY OF THE INVENTION

The invention is based on the problem of providing a possibility of separating any desired amount of cutting sections from a single cardboard web and to combine these sections individually at a predetermined distance from one another with the running web, for example a paper web. In addition this combining of the individual cardboard sections with the running web is to be effected by introducing only a single glue applicating device. If the problem in accordance with the invention is solved, an essential simplification of the machine for carrying out this method will be attained, because in that case only a single roll is required for the cardboard reinforcements and also only a single glue applicating device for applying these cardboard sections onto the moving web.

It may be necessary to have four cardboard cutouts for a single shopping bag, which are torn off as a unit from the moving cardboard web. This cardboard section is provided with transverse perforations before tearing, and this section which may be defined as a partial cut unit in this case comprises four perforated individual parts. This partial cut unit can be accelerated to a speed that is greater than the feeding velocity of the cardboard web. However, the advancing speed of the partial cut unit provided in this sense in accordance with the invention is selected to be slower than the advancing speed, for example, of the paper web onto which the reinforcing strips are to be glued. This partial cut unit with the transverse perforations that are already applied to it is subsequently fed to a second tearing device which runs at the speed of the paper web. In this connection the individual cardboard sections are separated from the partial cut unit one after the other and combined with the paper web at the predetermined distance from one another while using a glue-applicating device. Due to the difference of the velocity between the running paper web and the accelerated individual cardboard strips, the spacing between the individual cardboard strips, for example on the paper web, is achieved .

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and details of the invention will become apparent from the following description of the embodiments illustrated in the drawings, in which

FIG. 1 is a side view of a device for gluing cardboard stiffeners onto a work material web,

FIG. 2 shows the cardboard reinforcing blanks in multiples of four applied to the web of material,

FIG. 3 shows a folded shopping bag with glued-on reinforcing strips,

FIG. 4 shows the same operation as in accordance with FIG. 3 with cut blanks in three parts,

FIG. 5 is a folded shopping bag in accordance with FIG. 4,

FIG. 6 shows a cardboard web with cut blanks in two parts, and

FIG. 7 shows a shopping bag made from the cut blanks in accordance with FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

The web 1 of reinforcing or stiffening material, i.e., a more or less stiff cardboard web, is pulled from a roll (not shown) by the pair of pulling rollers 2, 3 and is perforated by the bottom cutter 4 and the top cutters 5, 6 cooperating therewith to form a predetermined number of partial cuts or sections of predetermined length. The feeding velocity of the rollers 2, 3 is determined by the change gear 7 which is seated on a shaft that is driven by the machine and makes one revolution per bag.

The perforated cardboard section is then torn off by the pair of tearing rollers 8, 9 and advanced to the transport rollers 10, 11 and 12, 13. These rollers operate at the same velocity as the tearing rollers 8, 9, and they are connected by suitable toothed gears. The shaft 14 also operates at a speed of one revolution per bag and carries the eccentrics 15. Levers 16 with eccentric rollers 17 are disposed upon eccentric 15, and the eccentric rollers 17 are linked with lug bars 18, 19 to levers 20, 21. These levers effect the pivoting of the pair of tearing rollers 8, 9 and of pair of transport rollers 10, 11. As soon as the predetermined number of preperforated cardboard cuts or sections has passed the cutter station, the tearing rollers 8, 9 engage and accelerate the number of the cardboard strips to their velocity while at the same time also, the transport rollers 10, 11 are seated or engaged. This number of the cardboard strips which are advanced more rapidly and which are perforated may be defined as a partial cut section unit.

The shaft 14 drives the drive wheel of the segment shaft 24 by way of intermediate gears 22, 23. On this segment shaft 24 segments 25 are mounted which operate at the same feeding speed as the paper web 26. In addition a toothed gear 27 is secured to the segment shaft 24 which drives the lower transport roller 10 by way of toothed gears 28, 29.

Owing to the smaller circle of the gear 27, the transport shafts and the tearing rollers 8, 9 run at a slower speed than the running paper web 26. As soon as the perforated cardboard sections arrive in the region of the segments 25 they are united with the paper web 26 which previously had applied to it a suitable coating of glue at station 36. Since the roller with the segments 25 and the roller 34 for the web 26 operate at a greater speed than transport rollers 10, 11, these elements constitute a second tearing station.

The tearing means for each piece of cardboard of a partial section is formed by segment shaft 24 that carries segments 25 in cooperation with the guide roller 34 for the paper web located below it. The tearing rollers 8 and 9 operate in a manner that for the purpose of tearing the partial sections they are disposed on the section located on the section before the last perforation so that the tearing occurs at the last perforation. The partial sections are subdivided into individual sections in the same manner. The individual cut which is disposed forward in the direction of transport is accelerated by the velocity of the segments 25 which travel at the speed of the paper web, while the next following cut is held to the speed of rollers 12 and 13 rotating at lower speed. Thus there is only one perforation between the tearing elements where the tear can take place.

FIG. 2 illustrates a cut section or blank having four cardboard cuts, and the subsequent separating line of the paper web blank is indicated by line 30.

FIG. 3 shows a folded bag in accordance with FIG. 2, and the subsequent folding line is indicated at line 31. The cardboard blanks 1 and 1c and 1a and 1b are now registering and are provided with hand grip cutouts 32, 33.

FIGS. 4 and 5 show a running paper web 26 with the subsequent cutting line 30 and the folding line 31. In this instance only three cardboard blanks 1a, 1b, 1c have been glued on, while later in the finished bag the cut 30 is taken through the center of the cardboard blank 1b and thus divides it in two parts.

The punching of the hand grip cutout 32 is made in the cardboard blanks 1a and 1c, while only a flap 33 is punched into the cardboard blank 1b.

FIGS. 6 and 7 show the gluing of two cardboard blanks 1a and 1b where these two blanks are of different width. This different width is obtained in that the second perforating cutter 6 is disposed at a different distance from the perforating cutter 5. Inasmuch as in this case a double flap is formed with respect to the folding line 31, the cutting line 30 results in three cardboard blanks of equal width.

In accordance with the invention the number of cardboard blanks or paper blanks to be glued on may be varied as desired, and besides it is possible by utilizing suitable gearing to make the distances between the individual parts or blanks as large or as small as desired. Thus it is possible to provide a stepless or continuous control transmission 35 for adjusting to different intermediate velocities, in which connection the intermediate velocity is derived from the main segment shaft 24.

The invention has been described with reference to the embodiments illustrated, and what it is desired to protect by letters patent of the United States is set forth in the appended claims.

Claims

I claim:

1. Method of gluing reinforcing strips onto a moving paper web or the like in spaced relation to one another, said method comprising the steps of feeding a web of reinforcing material such as cardboard to the pulling rollers of the apparatus, providing perforations in the continuously running reinforcing web transversely of the reinforcing web at predetermined desired distances from one another, tearing the desired number of reinforcing strips from the reinforcing web thus prepared at a first tearing station while only one perforation is located between the tearing elements of said first station at a feeding velocity greater than that of the reinforcing web, but lower than the velocity of the paper web onto which the reinforcing strips are to be glued, and feeding the perforated and still connected reinforcing strips to a second tearing station which operates at the velocity of the paper web, and while only one perforation is located between the tearing elements of the second tearing station and the reinforcing strips are retarded, then combines the reinforcing strips spaced at a desired distance from one another with the paper web while only one glue-applying device is employed.