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Patent Searching and Data


Title:
METHOD FOR MANUFACTURING A CONVEYOR APPARATUS AND A CONVEYOR APPARATUS MANUFACTURED BY THE METHOD
Document Type and Number:
WIPO Patent Application WO/2009/101248
Kind Code:
A1
Abstract:
The invention relates to a method for manufacturing a conveyor apparatus, a conveyor screw, in which method at least one object longitudinally hollow and open in both ends is formed in order to achieve a threaded surface on the inner surface of the object and/or on the outer surface of the object. According to the method round at least one object (1,21,42,56), longitudinally hollow and open at least in one end, it is installed at least one-piece mould (2,22,41,53), which is shaped as a holding surface of a desired threaded surface and that it is led into the object (1,21,42,56) rounded by the mould (2,22,41,53) material, wherein it is created pressure, and by means of the pressure it is achieved a threaded surface (12, 13,32,44,57), which can be utilized in transportation of material from one position to each other.

Inventors:
TORVINEN TERHO (FI)
TUOMI JUKKA (FI)
AUTERO MARKKU (FI)
Application Number:
PCT/FI2009/050100
Publication Date:
August 20, 2009
Filing Date:
February 09, 2009
Export Citation:
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Assignee:
OUTOKUMPU OY (FI)
TORVINEN TERHO (FI)
TUOMI JUKKA (FI)
AUTERO MARKKU (FI)
International Classes:
B21D26/02; B65G33/12
Foreign References:
US6497030B12002-12-24
AT384966B1988-02-10
DE19724623A11998-01-02
US6176114B12001-01-23
JP2001010713A2001-01-16
JPH04272001A1992-09-28
US6497030B12002-12-24
Other References:
See also references of EP 2242594A4
Attorney, Agent or Firm:
OUTOKUMPU OYJ, LEGAL AFFAIRS AND IPR (Espoo, FI)
Download PDF:
Claims:
CLAIMS

1. Method for manufacturing a conveyor apparatus, a conveyor screw, in which method at least one object longitudinally hollow and open in both ends is formed in order to achieve a threaded surface on the inner surface of the object and/or on the outer surface of the object, characterized in that round at least one object (1 ,21 ,42,56), longitudinally hollow and open at least in one end, it is installed at least one-piece mould (2,22,41 ,53), which is shaped as a holding surface of a desired threaded surface and that it is led into the object (1 ,21 ,42,56) rounded by the mould (2,22,41 ,53) material, wherein it is created pressure, and by means of the pressure it is achieved a threaded surface (12,13,32,44,57), which can be utilized in transportation of material from one position to each other.

2. Method according to the claim 1 , characterized in that material led into the object (1 ,21 ,42,56) rounded by a mould (2,22,41 ,53) is liquid.

3. Method according to the claim 2, characterized in that material led into the object (1 ,21 ,42,56) rounded by a mould (2,22,41 ,53) is water.

4. Method according to the claim 1 , characterized in that material led into the object (1 ,21 ,42,56) rounded by a mould (2,22,41 ,53) is elastomer.

5. Method according to any of the preceding claims, characterized in that in connection with forming of a threaded surface (12,13,32,44,57) at least one control tube (15,16,52) to be joined with the conveyor apparatus (8,28,43,51 ) is joined with the threaded surface (12,13,32,44,57).

6. Conveyor apparatus, a conveyor screw, manufactured by the method of claim 1 , characterized in that the conveyor apparatus (8,28,43,51 ) contains at least one threaded surface (12,13,32,44,57) and at least one control tube (15,16,52).

7. Conveyor apparatus according to the claim 6, characterized in that the control tube (15,16,52) of material is on the surface essentially straight.

8. Conveyor apparatus according to the claim 6, characterized in that the control tube (15,16,52) of material is on the surface essentially threaded.

9. Conveyor apparatus according to the claim 6, characterized in that the thread pitch of the threaded surface (12,13,32,44,57) in the conveyor apparatus (8,28,43,51 ) contains an essentially plane-like bottom surface, an essentially plane-like top surface and a wall connecting the bottom surface and the top surface and perpendicular to the bottom surface and the top surface.

10. Conveyor apparatus according to any of the preceding claims 6 - 9, characterized in that the thread pitch of the threaded surface (12,13,32,44,57) in the conveyor apparatus (8,28,43,51 ) contains convex surfaces joined to each other, in which case the arched part of the surfaces forms the bottom of a threaded surface and the contact points of two adjacent arched parts form the top point of the threaded surface.

11. Conveyor apparatus according to any of the preceding claims 6 - 9, characterized in that the thread pitches in the threaded surface (12,13,32,44,57) are formed at an essentially equal distance from each other.

12. Conveyor apparatus according to any of the preceding claims 6 - 9, characterized in that the thread pitches in the threaded surface

(12,13,32,44,57) diverge from each other when viewing in the moving direction of the conveyor apparatus.

13. Conveyor apparatus according to any of the preceding claims 6 - 9, characterized in that the thread pitches in the threaded surface

(12,13,32,44,57) converge to each other when viewing in the moving direction of the conveyor apparatus.

14. Conveyor apparatus according to any of the preceding claims 6 - 9, characterized in that in the conveyor apparatus (8,28,43,51 ) two materials are transported essentially simultaneously.

15. Conveyor apparatus according to any of the preceding claims 6 - 9, characterized in that the longitudinal cross section of the conveyor screw in the conveyor apparatus (8,28,43,51 ) is conical.

Description:

METHOD FOR MANUFACTURING A CONVEYOR APPARATUS AND A CONVEYORAPPARATUS MANUFACTURED BYTHE METHOD

This invention relates to a method for manufacturing a conveyor apparatus, a conveyor screw and to a conveyor apparatus, a conveyor screw manufactured by the method, in which method hydroforming is utilized.

Hydraulic forming or hydroforming is forming of a plate, closed object or a tube by using static liquid pressure. As liquid it can be an emulsion of water or oil. The liquid pressure is usually in an order of 3000 - 5000 bar. Elastomers can also be used in the hydroforming. Hydroforming gives freedoms for the design of the object to be formed, it can save tool costs and refrain welding joints. Typical products made by hydroforming are complicated tube objects.

From the US patent 6,497,030 it is known a manufacturing method using hydroforming for a cooperating lead screw and sleeve mechanism adapting the rotating movement linearly. In the method an inner sleeve, an intermediate sleeve, and an outer sleeve are positioned within each other concentrically and these sleeves are expanded by hydroforming so, that an outer thread is formed on the inner sleeve and an inner thread is formed in the outer sleeve. According to the method, the intermediate sleeve is removed after hydroforming for instance by melting or leaching. The space between the inner sleeve and the outer sleeve allows free mutual rotation of the sleeves in order to ensure smooth rotation of the screw. According the US patent 6,497,030 the inner sleeve and the outer sleeve can be hydroformed also separately.

The screw and sleeve mechanism manufacture according to the US patent 6,497,030 is objected only to transmit and adapt rotation movement to rectilinear movement. Thus strain caused by the movement is aligned only to the screw and the sleeve.

The object of the present invention is to achieve a method to manufacture from a tubular object using hydroforming a conveyor apparatus, a conveyor screw, which threaded surface positioning on the outer surface and/or on the inner surface is utilized to convey material from one position to another. The invention also relates to a conveyor apparatus, a conveyor screw manufactured by the method. The essential features of the invention are enlisted in the appended claims.

To the conveyor apparatus, conveyor screw in accordance with the invention it is created at least one threaded surface, which makes possible to convey material, by hydroforming at least one longitudinally hollow and at least from one end, advantageously from both ends open object, in which case it is created to the hydroformed hollow object a threaded surface either on the inner surface of the hollow object or on the outer surface of the hollow object. As one alternative embodiment for the conveyor screw in accordance with the invention it is also that the threaded surface is created both on the inner surface of the hollow object and on the outer surface of the hollow object. According to the invention the hollow object to be utilized is essentially tubular, in which case the outer diameter and the inner diameter of the object for the whole length of the object are kept essentially unchanged, or the outer diameter and the inner diameter of the object are linearly changed for the whole length of the object, in which case the longitudinal cross section of the object is conical.

According to the invention, by hydroforming at least two initially essentially hollow objects, hydroforming in order to create a threaded surface can be carried out for the objects either simultaneously or separately for each object.

The threaded surfaces for two separate objects can be in the desired moving direction of material either parallel or divergent. After hydroforming the parts having a threaded surface can be, when desired, installed concentrically within each other. At least when utilizing in the conveyor screw in accordance with the invention one threaded surface it can be joined to the threaded surface mechanically in the longitudinal direction of the threaded surface

advantageously at least one external part for conveying material advantageously.

The shape of thread in the threaded surface of the conveyor apparatus created by hydroforming according to the invention contains in one preferred embodiment an essentially plane-like bottom surface, an essentially plane-like top surface and a wall, which is connective for the bottom surface and the top surface and which is perpendicular to both the bottom surface and the top surface. The contact points between the wall and the thread surfaces are advantageously provided with bevellings and/or roundings. The shape of thread in the threaded surface according to the invention can also contain concave or respectively convex surfaces joined to each other, in which case the arched part of the surfaces form the bottom of the threaded surface and the contact points of two adjacent arched parts form the top point of the threaded surface. One threaded surface according to the invention can have shapes of thread different from each other.

In the threaded surface of the conveyor apparatus according to the invention the thread pitches are advantageously formed at an essentially equal distance from each other. The thread pitches depending on the material to be conveyed in the conveyor apparatus according to the invention can be formed to each other also so that the thread pitches either diverge or converge to each other when viewing from the moving direction of the conveyor apparatus. According to the invention, in the same part having the threaded surface it can be both thread pitches formed at equal distances, thread pitches diverging from each other and thread pitches converging to each other. The part having the thread surface according to the invention can also contain parts joined to each other, in which parts one part has thread pitches at equal distances, one part has thread pitches diverging from each other and one part has thread pitches converging to each other. The part having the thread surface according to the invention can also be such that the part having the threaded surface has both thread pitches at equal distances to each other and thread pitches diverging from each other

or both thread pitches diverging from each other and thread pitches converging to each other or both thread pitches converging to each other and thread pitches at equal distances. The thread pitches at equal distances, the thread pitches diverging from each other and thread pitches converging to each other can from the thread pitch of view be either similar to each other or different from each other depending on the material to be conveyed and on the treatment stage of material.

When utilizing in the conveyor apparatus according to the invention an object having a linearly changing diameter or an object, where the thread pitch varies between the separate parts of the conveyor apparatus it is achieved acceleration or deceleration in the transport speed of the material to be conveyed depending on that whether the diameter of the conveyor apparatus or thread pitch of the conveyor apparatus is enlarged or diminished when viewing in the moving direction of the conveyor apparatus. Further, if in the conveyor screw having a shape of an object with a changing diameter it is conveyed material, which volume can change during the conveyance, the pressure/tightness of material is increased or decreased depending on that in which course the diameter of the object is changed in relation with the moving direction of the material. Further, when it is utilized in the material conveyance according to the invention an object having linearly changing diameter, the axial adjustment of the conveyor screw or the tightness of the conveyor screw to the object having a linearly changing diameter can be both adjusted and repaired too big clearances caused by wear for instance between the conveyor apparatus and the cover object surrounding the conveyor apparatus by changing the position of the object having the linearly changing diameter.

The invention is described in more details in the following referring to the enclosed drawings, wherein Fig. 1 illustrates one preferred embodiment of the invention partly cut, in a schematic side view,

Fig. 2 illustrates a conveyor apparatus and external parts joined to the conveyor apparatus created by means of the arrangement in Fig. 1 in a schematic and partly cut side view,

Fig. 3 illustrates one another preferred embodiment of the invention partly cut, 5 in a schematic side view,

Fig. 4 illustrates a conveyor apparatus and external parts joined to the conveyor apparatus created by means of the arrangement in Fig. 3 in a schematic and partly cut side view,

Fig. 5 illustrates still one another preferred embodiment of the invention partly 10 cut, in a schematic side view,

Fig. 6 illustrates a conveyor apparatus and external parts joined to the conveyor apparatus created by means of the arrangement in Fig. 5 in a schematic and partly cut side view,

Fig. 7 illustrates one another preferred embodiment of the invention partly cut, 15 in a schematic side view,

Fig. 8 illustrates a conveyor apparatus and external parts joined to the conveyor apparatus created by means of the arrangement in Fig. 1 in a schematic and partly cut side view.

20 According to Figs. 1 and 2 a tubular object 1 is installed into a mould 2 having a hollow and circular interior so that the tubular object 1 is supported by the supporting members 5 and 6, which are installed outside the mould 2 in the vicinity of the ends 3 and 4 of the tubular object. The inner surface 7 of the mould 2 is shaped in a desired shape of thread for a conveyor screw 8 created

25 by the method according to the invention. The end 3 of the tubular object is connected to the inlet connector 9 through which it is led into the interior of the tubular object 1 liquid required in hydroforming, water. The opposite end 4 of the tubular object is connected to an outlet connector 10, through which water led into the interior of the tubular object 1 can be removed. The outlet connector

30 10 is provided with a stopper member for preventing the removal of water during hydroforming.

In order to hydroform the tubular object 1 it is led into the object 1 water, whereto it is created pressure and by means of pressure the tubular object 1 is shaped into a shape of the mould 2, in which case it is formed to the object both a threaded outer surface 12 and a threaded inner surface 13. In a stage after hydroforming the object 14 having the threaded outer surface and the threaded inner surface is pushed into a ring-like opening formed by two concentrically installed objects 15 and 16, in which case the object 14 having the threaded outer surface and the threaded inner surface can be mechanically fixed with the objects 15 and 16. Thus it is created a conveyor screw 8 according to the invention, with which screw it is possible to convey material in two separate thread planes.

In the embodiment according to Figs. 3 and 4 a tubular object 21 is installed into a mould 22 having a hollow and circular interior in the longitudinal direction so that the tubular object 21 is supported by the supporting members 25 and 26, which are installed outside the mould 22 in the vicinity of the ends 23 and 24 of the tubular object. The conical inner surface 27 of the mould 22 is shaped into a desired shape of thread for a conveyor screw 28 created by the method of the invention. The end 23 of the tubular object is connected to the inlet connector 29, through which it is led elastomer required in hydroforming into the tubular object 21. The opposite end 24 of the tubular object is connected to the outlet connector 30, through which elastomer led into the tubular object can be essentially removed. The outlet connector 30 is provided with a stopper member for preventing the removal of elastomer during hydroforming.

When manufacturing a conveyor screw in accordance with the invention it is created pressure into elastomer in a tubular object 21 , and elastomer is expanded and achieves forming of the tubular object 21 against a wall of a mould 22, in which case a desired threaded surface 32 is formed on the inner surface and the outer surface of the tubular object 21 , which threaded surface is conical in the longitudinal direction of the conveyor screw 28. After achieving the conveyor screw 28 the pressure targeted to elastomer is reduced and

elastomer is returned into the original shape when reducing pressure, in which case elastomer can be removed from the interior of the conveyor screw 28. To the conveyor screw 28 in accordance with the invention it is joined, when needed, at least one control tube 34 of material for controlling material to be conveyed on the outer surface of the conveyor screw 28 at least on the starting end of the moving direction of the conveyor screw 28.

In the embodiment according to Figs. 5 and 6 it is essentially used a structure solution illustrated in the embodiment according to Figs. 1 and 2 despite the fact that the shape of the mould 41 has been changed so that it is achieved by means of the mould 41 an essentially outwards convex threaded surface for a tubular object 42, which surface is used for a conveyor screw 43 of Fig. 6. The conveyor screw 43 of Fig. 6 is created so that the shape of the mould 41 is changed so that it is achieved an outwards convex thread surface 44 for the tubular object 42.

According to Figs. 7 and 8 it is essentially used a structure solution in accordance with Figs. 1 and 2 in order to join during hydroforming to each other a conveyor screw 51 and a joined control tube 52 when a tubular object 56 is hydroformed. When compared with Fig. 1 a mould 53 is two-piece so that it is installed between the parts 54 and 55 of the mould a control tube 52. The part 54 of the mould is shaped so that it is achieved by means of the mould part in connection with hydroforming a threaded surface 57 for the conveyor screw 51. The part 55 of the mould forms a support surface for the control tube 52 in connection with hydroforming, in which case the threaded surface 57 of the conveyor screw 51 and the control tube 52 is fastened to each other as illustrated in Fig. 8.