IE74197B1

IE74197B1 - Improvements to bag making apparatus

Info

Publication number: IE74197B1
Application number: IE150591A
Authority: IE
Inventors: Austin Brady
Original assignee: Mach & Graphic Consultants Lim
Priority date: 1991-05-03
Filing date: 1991-05-03
Publication date: 1997-07-16
Also published as: BE1003294A6; IE911505A1; GB9209644D0; GB2255310A; GB2255310B

Abstract

Apparatus for making elongate bags from a roll of paper includes a longitudinal adhesive applicator 10, a paper folding stage 50 for folding the paper to a tubular form, a tube cutter 70, a transverse adhesive applicator 100 and a bag pick-up belt delivery system. During operation of the apparatus the bag pick-up delivery system runs at a speed greater than the cycle speed of the other integers of the apparatus. In this way, a completed bag is effectively removed from the apparatus at a high speed when the end of the bag is closed by the transverse adhesive applicator 100, thereby allowing the end of the following bag to be closed and thus enabling bags of considerable length to be produced.

Description

IMPROVEMENTS TO BAG MAKING APPARATUS The present invention relates to apparatus for making * bags, in particular elongate, paper bags.

The conventional system for the manufacture of bags uses the formation of a tube from a roll of material, e.g. paper. The paper is provided with a longitudinal application of adhesive, which when the material is folded retains the material in a tube. The pasted tube of material is then advanced to the cutting stage where the tube of material is cut into lengths. The cutting operation is usually performed using a beater which is a flail-like cutter which comes from underneath the tube of material and cuts its against a cutting blade. The end of each tube is then folded and pasted to form a bag. The completed bags are removed from the apparatus by means of a rotary cylinder which is provided with two or more sets of grippers spaced equidistantly about the circumference of the cylinder. The maximum length of bag which can be delivered using a rotary cylinder is half the circumference of the cylinder. Thus to produce a bag of 1.25 m (49) long, it would be necessary to have a rotary delivery cylinder having a diameter of at least 800 mm (31). Rotary delivery cylinders are extremely intricate and expensive pieces of apparatus as there are many moving parts located within the cylinder.

The present invention provides apparatus for making elongate bags from a roll of material, comprising the following integers, namely, unrolling means for unrolling a strip of material from the roll, tube forming means for , forming the strip into a tube, adhesive application means 741 97 - 2 for applying at least one seam of adhesive along an overlapping edge of the tube, roller means for applying pressure to the overlapping edges of the tube, cutting means for cutting the elongate tube of material into lengths, closing means for closing one end of each length of tube so as to form a bag and a bag pick-up mechanism for removing the completed bag from the apparatus, characterised in that the bag pick-up mechanism is operable to run at a speed which is effective to move a bag away from the apparatus at a speed greater than that at which the subsequent bag arrives, whereby a completed bag may be removed from the apparatus at the greater speed when the end of the bag is closed, thereby allowing the end of the following bag to be closed and thus enabling bags of considerable length to be produced.

Advantageously, the bag pick-up mechanism includes a pick-up belt and a variable speed motor operable to drive the pick-up belt so that the speed of the pick up belt can be adjusted to the optimum speed for a particular length of bag.

Conveniently, the cutting means includes two lengths of tube with a pair of beater blades provided on a beater wheel, so that one complete revolution of the beater wheel cuts two lengths of tube and in which the end closing means includes a pasting cylinder operable to go through two revolutions for every revolution of the beater wheel.

Preferably, bag overlapping means are provided between the cutting means and the end closing means and most preferably, the bag overlapping means includes retaining rollers operable to engage the bags and disengage from contact with the bags by means of at least one cam and cam follower, the lift of the cam being determined by the thickness of the overlapping bags.

Advantageously, the adhesive application means includes a longitudinal adhesive applicator which comprises a tray for adhesive, an adhesive pick-up wheel rotatable within the tray, an intermediate wheel engagable with the pick-up wheel so as to crush any non-liquid adhesive and an application disc engagable with the pick-up wheel, the application disc having one more rings about its circumference, the or each ring being contactable with the sheet of material so as to apply one or more longitudinal seams of adhesive thereto.

Conveniently, the tube forming means includes a gusset forming section, a final folding section and one or more draw rollers for drawing the formed tube of material through said sections.

Preferably, the end closing means includes a transverse adhesive applicator, comprising a folding blade and a pasting blade both of which are mounted on a rotatable shaft, and a tray for adhesive, an adhesive pick-up wheel rotatable within the tray, an intermediate wheel engagable with the pick-up wheel so as to crush any non-liquid adhesive and a pasting wheel engagable with the pick-up wheel and the pasting blade, whereby adhesive is transferred from the pasting wheel to the pasting blade to provide a transverse seam of adhesive to close the end of the bag.

The present invention also provides a method of making Figure 2 elongate bags from a roll of material, comprising unrolling a strip of material from the roll, forming the strip into a tube, applying at least one seam of adhesive along an overlapping edge of the tube, applying pressure to the overlapping edges of the tube, cutting the elongate tube of material into lengths, one end of each length of tube so as to form a bag and removing the completed bag from the apparatus, characterised by removing the bag by a bag pick-up mechanism which is operable to run at a speed which is effective to move a bag away from the apparatus at a speed greater than that at which the subsequent bag arrives, whereby a completed bag may be removed from the apparatus at the greater speed when the end of the bag is closed, thereby allowing the end of the following bag to be closed and thus enabling bags of considerable length to be produced.

The invention will hereinafter be particularly described with reference to the accompanying drawings, which show by way of example only one embodiment of bag making apparatus according to the invention. In the drawings: Figure 1 is a simplified side view of the rear section of the apparatus which includes an adhesive applicator for the longitudinal bag seam; Figures 1A and 1B are respectively, a side view and a perspective view of the adhesive applicator of Figure 1; is a simplified side view of the front section of the apparatus which includes the paper folding stages, the paper cutting stage and an adhesive applicator for the transverse bag seam; Figure 3 is a perspective view of a portion of the paper cutting stage and the transverse bag seam adhesive applicator; Figure 4 is a perspective view of a portion of the bag removal belts which are located at the front section of the apparatus; Figure 5 is a perspective view from the rear of the apparatus of the transverse bag seam adhesive applicator; Figures 5A and 5B are two perspective views from the rear of the apparatus of the transverse bag seam adhesive applicator; Figure 5C is a perspective view from the front of the apparatus of the transverse bag seam adhesive applicator; and Figure 6 is a perspective view from the front of a portion of the mechanism of the paper cutting stage.

Referring to the drawings, the apparatus for making bags includes a longitudinal adhesive applicator 10, a paper folding stage 50, a tube cutter 70, a transverse adhesive applicator 100, and a pick up belt delivery system 140.

The bags are manufactured from paper A which is unwound from the roll B through a printer C which prints the required markings on the paper. After the printing stage, the paper A is fed through the longitudinal adhesive applicator 10 where two longitudinal seams of adhesive D are applied to the paper. The adhesive is retained in a tray 11 in which is rotatably mounted a pick up wheel 12. The adhesive is then transferred to an intermediate wheel 13 before it is transferred to an applicator disc 14. Any lumps that may be in the adhesive are crushed between the pick up wheel 12 and the intermediate wheel 13 thus ensuring that the application disc 14 applies an even supply of adhesive to the paper A. A block of lubricating wax 15 is located at the adhesive applicator 10 and applies lubrication to the paper thus improving the efficiency of the subsequent operations which are shown in simplified format in Figure 2.

The paper folding stage 50 is in two sections, the gussett forming section 51 and the final folding section 52. The sheet of paper is drawn through this stage by three draw rollers 53. By having the folding operation in two sections, the draw on the rollers 53 is considerably reduced.

The formed tube now advances to the bag cutter 70 where the tube is cut into bag lengths by a beater (not shown). Two beater blades are attached to the rotating wheel of the beater, so that in one complete revolution of the beater wheel, two bags are cut.

Retaining rollers 72 (Figure 6) are provided at the bag cutter stage and these rollers 72 are activated to grip the tube during the cutting operation. At this stage in the manufacturing operation, there is an overlap between the cut tube and the uncut tube. Therefore the cam 74 gives an increased clearance to the rollers 72 to enable the double thickness of tube to pass beneath the rollers. The rollers 72 are moved by means of the arm 75 which is pivotable on shaft 76. The end of the arm 75 remote from the rollers is provided with a cam follower 78 which is engaged by the cam 74.

After the tube is cut, it is transferred from the tube cutter 70 to the transverse adhesive applicator 100 by transfer belts 102. The distance between the tube cutter 70 and the adhesive applicator 100 is increased to a distance greater than the length of tube by means of extension members 80. Referring to Figure, 5A, 5B, and 5C, the adhesive applicator 100 includes a folding blade 104 and a pasting blade 106 both of which are mounted on a rotating shaft 107. The pasting blade 106 picks up adhesive from a pasting wheel 108 which in turn picks it up from an intermediate roller 110 which picks up the adhesive from the pick up roller 112 which picks it up from the tray 113. Any lumps in the adhesive are crushed between the wheel 108, and the rollers 110 and 112.

After the end of a bag is folded and adhesive is applied by the adhesive applicator 100, the completed bag is removed from that section of the apparatus by the pick up belts 141, 142 of the delivery system 140. The pick up belts 141,142 transport the completed bags at a speed which is considerably greater than the operating speed of the rest of the apparatus, thus enabling the following tube to be folded and pasted. The pick up belts 141,142 transfer the completed bags under the table 143 around a large diameter wheel (not shown) and deliver the bags in a stack S on the table 143. The belts 141,142 are driven by a variable speed motor (not shown), so that the speed may be varied to deliver the optimum output for the length of bag being manufactured.

By modifying the apparatus as described above, it is possible to manufacture a wide variety of high quality elongate bags at a comparatively low capital cost.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the appended claims.

Claims

CLAIMS:

1. Apparatus for making elongate bags from a roll of material, comprising the following integers, namely, unrolling means for unrolling a strip of material from the roll, tube forming means for forming the strip into a tube, adhesive application means for applying at least one seam of adhesive along an overlapping edge of the tube, roller means for applying pressure to the overlapping edges of the tube, cutting means for cutting the elongate tube of material into lengths, closing means for closing one end of each length of tube so as to form a bag and a bag pick-up mechanism for removing the completed bag from the apparatus, characterised in that the bag pick-up mechanism is operable to run at a speed which is effective to move a bag away from the apparatus at a speed greater than that at which the subsequent bag arrives, whereby a completed bag may be removed from the apparatus at the greater speed when the end of the bag is closed, thereby allowing the end of the following bag to be closed and thus enabling bags of considerable length to be produced.

2. Bag making apparatus as claimed in Claim 1, in which the bag pick-up mechanism includes a pick-up belt and a variable speed motor operable to drive the pick-up belt so that the speed of the pick up belt can be adjusted to the optimum speed for a particular length of bag.

3. Bag making apparatus as claimed in Claim 1 or Claim 2, in which the cutting means includes two beater blades provided on a beater wheel, so that one complete revolution of the beater wheel cuts two bags and in which the end closing means includes a pasting cylinder operable to go through two revolutions for every revolution of the beater wheel.

4. Bag making apparatus as claimed in any one of the 5 preceding claims, in which bag overlapping means are provided between the cutting means and the end closing means.

5. Bag making apparatus as claimed in Claim 4, in which 10 the bag overlapping means includes retaining rollers operable to engage the bags and disengage from contact with the bags by means of at least one cam and cam follower, the lift of the cam being determined by the thickness of the overlapping bags.

6. Bag making apparatus according to any one of the preceding claims, in which the adhesive application means includes a longitudinal adhesive applicator which comprises a tray for adhesive, an adhesive pick-up wheel 20 rotatable within the tray, an intermediate wheel engagable with the pick-up wheel so as to crush any non-liquid adhesive and an application disc engagable with the pick-up wheel, the application disc having one more rings about its circumference, the or each ring being 25 contactable with the sheet of material so as to apply one or more longitudinal seams of adhesive thereto.

7. Bag making apparatus as claimed in any one of the preceding claims, in which the tube forming means includes 30 a gusset forming section, a final folding section and one or more draw rollers for drawing the formed tube of material through said sections. ♦

8. Bag making apparatus as claimed in any one of the preceding claims, in which the end closing means includes a transverse adhesive applicator, comprising a folding blade and a pasting blade both of which are mounted on a rotatable shaft, and a tray for adhesive, an adhesive pick-up wheel rotatable within the tray, an intermediate wheel engagable with the pick-up wheel so as to crush any non-liquid adhesive and a pasting wheel engagable with the pick-up wheel and the pasting blade, whereby adhesive is transferred from the pasting wheel to the pasting blade to provide a transverse seam of adhesive to close the end of the bag.

9. Bag making apparatus substantially as herein described with reference to and as shown in the accompanying drawings .

10. Elongate bags whenever manufactured by apparatus as claimed in any one of the preceding claims.

11. A method of making elongate bags from a roll of material, comprising unrolling a strip of material from the roll, forming the strip into a tube, applying at least one seam of adhesive along an overlapping edge of the tube, applying pressure to the overlapping edges of the tube, cutting the elongate tube of material into lengths, closing one end of each length of tube so as to form a bag and removing the completed bag from the apparatus, characterised by removing the bag by a bag pick-up mechanism which is operable to run at a speed greater than the cycle speed of other integers of the apparatus, whereby a completed bag may be removed from the apparatus at a high speed when the end of the bag is closed, thereby allowing the end of the following bag to be closed and thus enabling bags of considerable length to be produced.

12. A method of making elongate bags as claimed in Claim 11, including adjusting the speed of the bag pick-up mechanism to the optimum speed for a particular length of bag.

13. A method of making elongate bags as claimed in Claim 11 or Claim 12, including cutting two lengths of tube with a pair of beater blades provided on a beater wheel, so that one complete revolution of the beater wheel cuts two lengths of tube and including operating a pasting cylinder to go through two revolutions for every revolution of the beater wheel so as to close the end of two tubes during every revolution of the beater wheel.

14. A method of making elongate bags as claimed in any one of Claims 11 to 13, including overlapping the bags which are positioned after cutting the tubes prior to closing the ends thereof.

15. A method of making elongate bags as claimed in any one of Claims 11 to 14, including forming the tube by firstly forming a gusset and then folding the formed gusset to form a tube and drawing the formed tube through the gusset forming section and final folding section.

16. A method of making elongate bags according to Claim 11, substantially as herein described with reference to the accompanying drawings.

17. Elongate bags whenever made by a method in any one of Claims 11 to 16.