WO1989008059A1

WO1989008059A1 - Strengthener for cylindrical items

Info

Publication number: WO1989008059A1
Application number: PCT/FI1989/000036
Authority: WO
Inventors: Bo-Erik Lindewald; Arto Halle
Original assignee: Pacwire Oy Ab
Priority date: 1988-03-01
Filing date: 1989-02-28
Publication date: 1989-09-08
Also published as: SE8902877D0; SE8902877L; SE500797C2; AU3203389A

Abstract

The invention relates to a method and device for strengthening the cylindrical item, especially, for strengthening a paper roll. According to the invention an essentially tube shaped bag closed on its both ends (2a, 2b) and equipped with an inflation valve (3) is placed into the cylindrical item in order to press the outer surface of the bag (1) against the inner surface of the cylindrical item.

Description

STRENGTHENER FOR CYLINDRICAL ITEMS

Big paper rolls and other similarily shaped items made of other materials are handled with tools that grip the item in the axial direction.

In such cases, for instance, both ends of the core of a paper roll are protected by using conically shaped props. Nevertheless, the grippers of the lifting device often press the roll with a force that is too strong and is uneven against the inner surface of the roll. This results that the middle part of the roll can be pressed together. This method does not work satisfactorily despite of the fact that it is quite expensive. Besides that the conical core protectors are very expensive and the high labour costs are involved, too.

Huge cylindrical items which are extremely long are often transported axial-horizontally. Therefore, the cylindrically shaped items will be deformed by their own weight or by chocks during transportation.

Another alternative to using grippers to be pressed against paper roll is to use the vacuum lifting method. This method makes it safe to lift the items by a device which creates a vacuum in the other end of the roll. The disadvantages of this method are high costs and that the specially designed devices are needed. Furthermore, this method is quite slow.

Another method for moving cylindrical items is described in U.S. Patent No. 4.173.368 and FI Patent No. 47333. In those patent publications there are described such gripping apparates which by air pressure frictionally grip the interior surface of a cylindrical item during lifting or handling. Upon removal of the air pressure cylindrical item is released. Neither of these two apparates described solves the problem how to protect the cylindrical items during transportation and warehousing. These apparatus are meant only to be used in lifting devices.

The purpose of the present invention is to solve the problem described above.

The invention is essentially described in attached claims and drawings.

In order to reinforce a cylindrical item, for example a paper roll or the like, a tubular bag which is closed at both ends, is placed into the cylindrical item. To the other end of the bag a inflation valve is attached. The size of the bag is dimensioned to cause a pressure against the inner surface of the cylinder when it has been inflated with a pressure of 0.1 - 2.0 bar, preferably 0.5 bar. This pressure will be directed evenly against the whole inner surface of the cylinder, or at least against the major part of the inner surface.

In the attached drawings in Fig. 1 is a reference numeral 1 is the outer surface of the bag pressing against the inner surface of the cylindrical item or items, for instance a paper roll or similar. Numerals 2a and 2b are the ends of the bag, respectively, and numeral 3 is the inflation valve.

In Fig. 2 it is showed schematically how by means of the invention the invention is used besides to reinforce the cylindrical items, it is also used to unitize (to hold together) for example three cylindrical items which are piled on each other. These three cylindrical items can also lie down horizontally one by one. By varying the dimensions of the bag the invention can be applied to such cylindrical items whose wall is essentially thinner than for example that of paper rolls. This can be applied for instance when an unprotected plastic tube becomes flat by the outer pressure.

Another application is that the bag is fitted to fill wholly and air tightly the inside of the-cylinder. In this application no additional packings are needed for using this method. This also saves time as the evacuation time of the hole is much more faster.

According to the description and the patent claims the bag can be formed according to special needs, the material can be varied according to special needs and the dimensions can be varied to fit to the particular cylindrical item which shall be strengthened, for instance, a paper roll or like.

Claims

1. A method developed to strengthen a cylindrical item during warehousing and handling, c h a r a c t e r i z e d in that an expanding closed room which leaves as an organic part of the item is placed into the cylindrical item, having a suitable pressure.

2. A method to strengthen a cylindrical item as claimed in claim 1 c h a r a c t e r i z e d in that a bag made of an air tight and flexible material placed into the cylindrical item, which when inflated has a slightly bigger diameter than the inner diameter of the cylindrical item, that the bag is inflated with gas at a pressure of 0.1 - 2.0 bar, preferably 0.5 bar and that the inflation of gas is done in order to cause the bag to be pressed against the inner wall of the cylindrical item and to strengthen both the tensile and pressure strength of the item.

3. A method as claimed in claims 1 and 2, c h a r a c t e r ! z e d in that a strengthener of cylindrical items which is pressed against the whole inner surface of the cylindrical item or at least against a considerably large part of the inner surface thereof.

4. A method as claimed in claims 1 and 2, c h a r-a c t e r i z e d in that the method is used for strengthening pipes or items of a similar shape.

5. A strengthener of cylindrical items as claimed in claims 1 and 2, c h a r a c t e r i z e d in that it is made of an air tight material such as plastic, fabric, rubber or a combination of fabric and plastic or fabric or similar.

6. A strengthener of cylindrical items as claimed in claim 5, c h a r a c t e r i z e d in that it can be used to unitize one or several cylindrical items when it strengthens the items both horizontally and vertically.

7. A strengthener of cylindrical items as claimed in claims 5 and 6, c h a r a c t e r i z e d in that it can be made either at the length corresponding that of the cylindrical item or at the total length corresponding that of the several cylindrical items to be unitized.

8. A strengthener of cylindrical items as claimed in claims 5, 6 and 7, c h a r a c t e r i z e d in that the diameter of the bag is the same or slightly bigger than the inner diameter of the item to be strengthened.

9. A strengthener of cylindrical items as claimed in claims 5, 6, 7 and 8, c h a r a c t e r i z e d in that an inflation valve (3) for inflation of gas is attached to the streghthener.