DK177251B1

DK177251B1 - An expandable shaft

Info

Publication number: DK177251B1
Application number: DKPA200900083A
Authority: DK
Inventors: Karsten Oredsen Weber
Original assignee: Lindale Produkter Karsten Oredsen Weber
Priority date: 2009-01-20
Filing date: 2009-01-20
Publication date: 2012-08-13
Also published as: CN102292276B; EP2389332A1; EP2389332B1; US20120018565A1; CN102292276A; DK200900083A; WO2010083830A1

Abstract

The present invention relates to an expandable shaft (1) for insertion into a core, the cx pandable shaft have a longitudinal extension and comprising: - a profile (4), which extends in the longitudinal direetion of the shaft, the profile tom prising a plurality of longitudinal grooves; - infiatable and expandab chambers which are adapted to be arranged in the grooves; - gripping means (3) which are arranged in connection to the expandab chamber, the gripping means being adapted to radial movement between a first position and a sec- ond position in view of an expansion of the infiatable and expandable chamber so that the gripping means (3) are movable in a radial direction between a first position and a second position depending on an expansion of the expandable chamber wherein - an outer cylindrical tube is arranged outside the profile (4), the outer cylindrical tube comprising a plurality ofopenings, and wherein the gripping means (3) are aligned with the openings of the tube so that the gripping means can project through and be yond the tube in a radial direetion of the shaft during the expansion of the expand able chamber.

Description

DK 177251 B1

AN EXPANDABLE SHAFT INTRODUCTION

5 The present invention relates to an expandable shaft for rotatably supporting tubular cores of rolls of material which have to be supported during winding or unwinding processes.

The material could be paper but could also be other types of web material such as textiles, metal, plastic films, foils, tapes etc. The expandable shaft for insertion into a core is of the type having a longitudinal extension and comprising a profile, which extends in the 10 longitudinal direction of the shaft, the profile comprises a plurality of longitudinal grooves, inflatable and expandable chambers which are adapted to be arranged in the grooves and gripping means which are arranged in connection to the inflatable and expandable chambers, the gripping means being adapted to radial movement between a first position and a second position in view of an expansion of the inflatable and expandable 15 chambers so that the gripping means are movable in a radial direction between a first position and a second position depending on an expansion of the expandable chambers.

The gripping means are a type of locking-release means which can be pushed into contact with the inside of a core of a roll to be winding in such a way that the core is maintained 20 in the same position on the shaft during the winding process. The gripping means are holding the core in position by pressing the gripping means on or into the inside of the core.

BACKGROUND OF THE INVENTION 25

Expandable shafts for rotatably supporting heavy large-dimension rolls are well known. Expanding of the shafts is usually done with pure mechanical forces or with fluid pressure which most often is pneumatic, since air under pressure is normally available in manufacturing plants. The shaft according to the invention is of the fluid pressure type.

30 US patent 3,053,467 discloses one type of fluid pressure expandable shafts, where the shaft has a hollow shaft with an outer cylindrical shell comprising multiple radial open- 2 DK 177251 B1 ings forming a symmetrical pattern there over, a series of individual T-sectioned gripping members lying in the respective openings, an inflatable chamber in the form of a centrally placed elongated annular chamber being in connection with the gripping member.

When the annular chamber inflates the gripping members are deformed outwardly and 5 into engagement with a core.

This type is also known from patent application US-A-4,461,430, DE-A1- 195 24 489 and DE-U1- 295 10 88 3.

10 The above-described expandable shaft suffers from the disadvantages that all the gripping members are individually in connection with the surface of the annular inflated chamber.

If the gripping elements do not have equal stiffness in all radial directions, it will lead to wobble during winding. The wobble during winding result in a winding where the edges of the rewinded material will not be exactly perpendicular to the axis of the core and fur-15 thermore the wobbling produces imbalance in the mechanical parts and causes wear down of the shaft, bearings and connected parts. The wobbling during winding can also result in poor or useless products. For example, if the shaft is used in printing works the wobbling can result in bad prints. The annular inflated chamber is liable to be damaged, and is often burst. When the air is discharged from the inflatable chamber the latter is 20 deformed, as a result of which the gripping member may drop in the hollow shaft. In such a case, because of the internal structure of the shaft it is difficult to repair the shaft at the working site and the shaft has to be returned to the manufacturer.

Furthermore this type has the problem that great external forces are applied to the annular inflatable chamber and the chamber may be moved laterally.

25 The annular inflatable chamber with only one air bag further tends to expand the core into an out-of round condition, and grind off material from the inner side of the core.

Another type of expanding shaft is the profile type where the shaft has a polygonal form and the surface of the shaft is provided with angularly equidistant longitudinal recesses of 30 quadrangular shape, carrying one or more air chambers which on expanding cause pins to move radially and lock the shaft against the core of the roll, these pins being positioned 3 DK 177251 B1 on the air chambers. This type of shaft is known from, for instance, US-A-5 681 007 and DE-A-44 39 035.

Because of their polygonal form and the recesses, this type of expanding profile shaft 5 have to be manufactured of materials of high mechanical strength and rigidity. These types of shafts are often made of extruded aluminium. Extruded aluminium profile shafts do not always have enough mechanical strength and are vulnerable to stroke and relatively expensive to produce. If the shaft needs both good centring and high strength at the same time, the shafts are often made of milled steel and are very expensive to produce.

10 Steel shafts furthermore have a considerable weight and demand extra and more expensive handling tools during the mounting and dismounting process.

Besides, because of the outer form, these types of shafts are vulnerable to stroke in connection with replacement of the cores. Damage to the profile can result in sharp comers 15 and consequently in puncturing of the air chamber and vulnerable end pieces.

US-A-3,552,672 discloses a drive spindle with inflatable hoses arranged in notches in the spindle surface. Longitudinal rails of sheet metal are interconnected by means of welded spots and are attached to the surface by means of rivets.

20

This type of spindles is relatively unflexible and with relatively low strength, especially bending strength.

Thus, there is a need for providing a flexible solution to the above-mentioned disadvan-25 tages and to provide an expandable shaft with increased bending strength and at the same time to reduce costs and total weight.

DESCRIPTION OF THE INVENTION

30 An object of the present invention is to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an ex- 4 DK 177251 B1 pandable shaft with increased bending strength and at the same time reduce costs and total weight.

It is also important that the core does not move axially on the shaft during winding, oth-5 erwise the edges of the rewound paper will not be exactly perpendicular to the axis of the core.

It is also an object of the present invention to provide a shaft that is simple in construction, inexpensive to manufacture, and easy to disassemble for maintenance and repair.

10

Still another object of the invention is to provide a shaft that has a minimum number of different parts, to reduce number and cost of spare parts.

The above objects, together with numerous other objects, advantages and features, which 15 will become evident from the below description, are accomplished by a solution in accor dance with the present invention in that the expanding shaft comprising an outer, continuous cylindrical tube without joints which is arranged outside the profile, the outer continuous cylindrical tube without joints comprises a plurality of openings, and the gripping means are aligned with the openings in the tube so that the gripping means can 20 project through and beyond the tube in a radial direction of the shaft during the expansion of the expandable chamber.

Shafts comprising an outer continuous cylindrical tubular structure without joints increase the rigidity and strength and in particular provide maximum resistance to bending 25 stress. With the increase of the strength from the outer continuous cylindrical tube without joints it will now be possible to use a cheaper and lighter profile. In total an expandable shaft comprising an outer continuous cylindrical tube without joints reduces the weight, the cost and increases the bending stress to which the shafts are inevitably subjected during rotation. The added strength furthermore increases the lifetime of the shaft.

30

According to one embodiment of the invention, the profile may have at least three longitudinal grooves. Three or more longitudinal grooves will enable the gripping means to 5 DK 177251 B1 support the core in at least three different places and thereby obtain a centring of the expandable shaft.

A preferred shaft according to the invention has a profile with three longitudinal grooves 5 which gives the best centring of the expandable shaft.

The expandable shaft may comprise a profile with three or six longitudinal grooves, the grooves preferable being arranged with an angle of 120° or 60°, respectively, between them. When the profile comprises 6 longitudinal grooves the inflatable chamber can be 10 inflated sequentially.

According to one embodiment the gripping means may extend in the longitudinal direction of the shaft or in a tangential direction. When gripping means extend in the tangential direction of the shaft they will provide uniform support to the core around a major 15 part of the circumference.

In an embodiment of the invention the shaft may comprise rails arranged in the grooves between the expandable chambers and the gripping means. The rails protect the inflatable chambers and contribute to a simple construction. In a further embodiment according to 20 the invention the gripping means may be connected to the rails.

In an embodiment according to the invention one or more elastic or spring members are arranged in connection with the rails, the elastic or spring members being adapted to force the rails into the grooves when the chambers are deflated. The elastic or spring 25 members can be a spring, an elastic bending, an O-ring, a rubber band or the like.

In an embodiment according to the invention the profile may be divided into a plurality of modules. In this way the profile can easily be manufactured in many different lengths.

30 In still a further embodiment the modules may be formed with depressions for the gripping means. Two modules can be put together and gripping means may extend partly over two modules.

6 DK 177251 B1

The expandable chambers may be expanded by pneumatic, since air under pressure is normally available in manufacturing plants.

5 Method for expanding an expandable shaft. The method comprising the steps of: placing the expandable shaft into a core, connecting an inflatable medium to the shaft, and - expanding the expandable chambers via the inflatable medium, so that the gripping means are moved radially outwards against an inner surface of the core, whereby the 10 shaft is aligned inside the core so that the core is fixated and held.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its many advantages will be described in more detail below with refer-15 ence to the accompanying schematic drawings, which for the purpose of illustration show some embodiments and in which:

Fig. 1 Illustrates schematically a perspective view of an embodiment where the gripping means extend in the longitudinal direction of the shaft and with the gripping 20 means in the first position.

Fig. 2 Illustrates schematically the embodiment of Fig. 1 with the gripping means in the second position.

25 Fig. 3 Illustrates schematically a perspective view of another embodiment where the gripping means extend in a tangential direction of the shaft with the gripping means in the first position.

Fig. 4 Illustrates schematically the embodiment of Fig. 3 with the gripping means in the 30 second position.

7 DK 177251 B1

Fig. 5 Illustrates schematically a perspective view of the embodiment of Fig. 4 where the outer continuous cylindrical tube without joints has been removed.

Fig. 6 Illustrates schematically the embodiment of Fig. 3, and Fig. 6(A) is a cross sec-5 tional view along line A-A of Fig. 6, and Fig. 6 (B) is a cross sectional view along line B-B of Fig. 6.

Fig. 7 Illustrates schematically a perspective view of an embodiment where the profile is divided into a plurality of modules.

10

Fig. 8 Illustrates schematically a perspective view of the inflation parts.

Fig. 9 Illustrates schematically the inflation distribution part of Fig. 8, and Fig. 9(A) is a cross sectional view along line A-A of Fig. 9, and Fig. 9(B) is a perspective view 15 of the inflation distribution part.

All the figures are highly schematic and not necessarily to scale, and they show only parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.

20

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

The invention will be more concretely described with reference to its preferred embodiment shown in the accompanying figures. In those figures, reference numeral 1 desig-25 nates the expandable shaft according to the invention. The expandable shaft 1 has an outer continuous cylindrical tube without joints 2 comprising a plurality of openings wherein gripping means 3 are aligned. The gripping means 3 can project through and beyond the tube in a radial direction of the shaft. The gripping means 3 are adapted to radial movement between a first position and a second position depending on not disclosed inflatable 30 chambers. In Fig. 1 the gripping means 3 are elongated in the longitudinal direction of the shaft 1 and with the gripping means 3 in the first position. During expansion of the not disclosed inflatable chambers the gripping means 3 will move from the first position to a 8 DK 177251 B1 second position beyond the outer continuous cylindrical tube without joints 2 as disclosed in Fig. 2. In the second position the gripping means 3 will be in contact with the inside of a core of a roll to be winding in such a way that the core is maintained in the same position on the shaft during the winding process. The gripping means 3 are holding the core 5 in position by pressing the gripping means 3 on or into the inside of the core. On the surface the gripping means 3 can furthermore be coated with an elastic material, or it can have a sticky surface, thereby securing a good grip on the interior face of the core without damaging it. In some situations it can be desirable that the gripping means 3 project into the inside of the core. In this case, the gripping means 3 can have a surface with one or 10 more spikes. The gripping means are uniformly placed on the shaft and a uniform pres sure exerted simultaneously thereon by the inflatable chambers. Hereby it will be apparent that the shaft will centre itself in the core as its overall diameter is increased by inflation of the chambers.

15 Fig. 3 discloses an embodiment of the invention where the gripping means 3 extend in a tangential direction of the shaft 1. The gripping means 3 are in the first position. Fig. 4 discloses the same shaft 1 as in Fig. 3, but here with the gripping means 3 in the second position.

20 Fig. 3 and Fig. 4 disclose the gripping means 3 without any surface. From the figures it is possible to see how the gripping means 3 can be replaced from the outside of the shaft 1 without dismounting the shaft 1.

Fig. 5 discloses an embodiment of the shaft 1 with tangential gripping means 3 where the 25 outer continuous cylindrical tube without joints 2 has been removed. In this embodiment the profile 4 has three grooves (in the perspective view only one groove is visible). The gripping means 3 are connected to rails 6 and the rails 6 are placed in the grooves. Upon inflating of the expandable chambers, not visible, the rails 6 with the connected gripping means 3 will move radially in the grooves and the gripping means 3 will be pushed 30 through and beyond the openings in the outer continuous cylindrical tube without joints, not shown.

9 DK 177251 B1

When the winding process is finished the core of the roll is removed from the expanding shaft 1 by deflation of the expanding chambers 7 whereby the pressure from the gripping means 3 on the inside surface of the core will stop and the gravitational effect will push the rails 6 with the gripping means 3 into the grooves. The gripping means 3 on the ven-5 tral side will still stretch beyond the openings in the outer continuous cylindrical tube without joints 2, but without any pressing forces it is therefore easy to remove the roll from the shaft 1. When the shaft 1 has to be placed in a new roll to be winded, the gripping means 3 on the ventral side still stretch beyond the openings in the outer continuous cylindrical tube without joints 2. Even though there are no pressure on these gripping 10 means 3, they can in some situation still complicate the replacement. One or more elastic or spring members 5 can be placed around or partly around the gripping means 3 or, as disclosed in Fig. 5, around the rails 6 will automatically also draw the gripping means 3 on the ventral side into the grooves. The elastic or spring member 5 can be made in any suitable form and material for instance a metal or plastic spring or a rubber band or elas-15 tic O-ring. When the expandable chamber is inflated, the elastic or spring means will open or stretch, and when the expandable chamber is deflated the elastic or spring means will contract and all the gripping means will be drawn into the grooves.

Fig. 6 discloses the embodiment of Fig. 5 including the outer continuous cylindrical tube 20 without joints 2, Fig. 6(A) discloses the cross sectional view along line A-A of Fig. 6, and Fig. 6(B) discloses a cross sectional view along line B-B of Fig. 6. The line A-A divides the shaft 1 opposite a spring member 5, the line B-B divides the shaft throughout the gripping means 3. The cross sectional view in Fig. 6(A) discloses an embodiment, where a spring member 5 is placed partly around the profile 4 and the rails 6 to automatically 25 draw the gripping means into the grooves when the expanding chambers 7 are deflated.

The number of elastic or spring members 5 per shaft depends on the length of the shaft.

The cross sectional view in Fig. 6(B) discloses the gripping means 3 drawn into the grooves also on the ventral side, because of the spring member 5 as disclosed in Fig.

6(A).

30

Fig. 7 discloses a perspective view of an embodiment of the invention where the outer continuous cylindrical tube without joints 2 is disclosed with openings in the outer cylin- 10 DK 177251 B1 drical tube. The profile 4 is built up in modules and has in this embodiment six longitudinal grooves 9. The gripping means 3 are arranged to be shifted hereby the gripping means 3 are in contact with substantially the entire circumferential face of the shaft and thereby secure a good grip on the interior face of a core without deforming or damaging same.

5 The modules can be formed with depressions 10 for the gripping means 3. The depressions 10 are formed such that two modules put together form space for a gripping means 3. The profile 4 may be formed by one single module assembled by alternating the profile modules between a reflection and a 60° rotation.

10 Fig. 8 discloses an embodiment where the shaft is divided into an inflation inlet part 11, a distribution part 12 and a shaft part 13. The distribution part 12 is disclosed in Fig. 9, and Fig. 9(A) is a cross-sectional view along line A-A of Fig. 9. The distribution part 12 is furthermore disclosed in perspective view in Fig. 9(B). Air inflates the expandable chambers 7 through the inlet valve 14 and via the distribution part 12. The distribution part 12 15 distributes the air into the tube inlet 15. In the disclosed embodiment the air is distributed into three tube inlets 15 according to a profile with three grooves with three inflatable chambers. The inflation may be provided in one or both ends of the shafts 1. A preferred embodiment is an embodiment where the expandable chambers have the form of tube pieces and are expanded by air from one or both ends of the tube pieces. Prior art often 20 uses a closed tube with a hole for inflation in the longitudinal side. Use of a tube piece according to the invention instead is a cheap solution without need for preparing a hole, tightening and further fittings.

The outer continuous cylindrical tube without joints may be manufactured of any sturdy 25 material, for example iron, steel, aluminium or other suitable materials.

The profile may be manufactured by an extrusion or casting process. A preferred material is plastic easy to process, relatively cheap and with low density.

30 Although the invention above has been described in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modi- 11 DK 177251 B1 fications are conceivable without departing from the invention as defined by the following claims.

Claims

An expandable shaft (1) for insertion into a core, wherein the expandable shaft has a longitudinal extension and comprises: 5. a profile (4) extending longitudinally of the shaft and comprising a plurality of longitudinal grooves (9); inflatable and expandable chambers (7) which can be placed in the grooves (9); gripping means (3) disposed in connection with the chambers (7) and prepared to perform a radial movement between a first position and a second position in accordance with an expansion of the inflatable and expandable chambers so that the gripping means (3) are movable in a radial direction between a first position and a second position depending on an extension of the expandable chambers (7), characterized by - an external, unbroken, cylindrical tube without joints (2) is arranged outside the profile and comprises a number of openings, and whereby the gripping means (3) are aligned with the openings of the tube, so that the gripping means can project through and beyond the tube in a radial direction of the shaft during the expansion of the expandable chambers.

A shaft (1) according to claim 1, characterized in that the profile comprises at least three longitudinal grooves (9).

A shaft (1) according to claim 2, characterized in that the profile comprises three or six longitudinal grooves (9), wherein the grooves are preferably arranged at an angle of 25 or 120 ° or 60 °, respectively.

A shaft (1) according to any one of the preceding claims, characterized in that the gripping means (3) extend in the longitudinal direction of the shaft.

A shaft (1) according to any one of claims 1-3, characterized in that the gripping means (3) extend in the tangential direction of the shaft. -2 - DK 177251 B1

A shaft (1) according to any one of the preceding claims, characterized in that rails (6) are arranged in the grooves (9) between the expandable chambers (7) and the gripping means (3).

A shaft (1) according to claim 6, characterized in that the gripping means (3) are connected to the rails (6).

A shaft (1) according to claim 6 or 7, characterized in that one or more elastic or resilient elements (5) are arranged in connection with the rails, 10 whereby the elastic or resilient elements are prepared to force the rails in. in the grooves when the air is taken out of the chambers.

A shaft (1) according to claim 8, characterized in that the element (5) is a spring, an elastic bend, an O-ring, a rubber band or the like. 15

A shaft (1) according to any one of the preceding claims, characterized in that the profile is divided into a number of modules.

A shaft (1) according to claim 10, characterized in that the gripping means (3) partially extend over two modules. DK 177251 B1 l / 7 2v \ Fig.2 2/7 DK 177251 B1 2 \ @i