Metal working – Method of mechanical manufacture – Combined manufacture including applying or shaping of fluent...
Reexamination Certificate
1997-03-28
2001-02-06
Echols, P. W. (Department: 3726)
Metal working
Method of mechanical manufacture
Combined manufacture including applying or shaping of fluent...
C082S169000, C269S048100, C279S002010, C083S054000
Reexamination Certificate
active
06182349
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for producing a seamless metallic belt, which is capable of use as a belt for a conveyor.
2. Description of the Related Art
Conventionally, an endless metallic belt, which is formed out of thin-plane shaped metallic material, is used for a belt of a conveyor.
This type of endless metallic belt is used for a belt for molding a synthetic resin film, a synthetic resin sheet, a synthetic resin board or the like. Particularly, a mirror belt finished to a mirror surface is used for producing an optical film, sheet, board or the like, that requires a very smooth surface.
As material of the aforementioned endless metallic belt, various metals are properly used especially, stainless material (SUS) inhabiting a generation of a rust and so on is heavily used for the mirror finished belt in order that evenness of the surface is not impaired.
The aforementioned endless metallic belts are produced with, for example by, a method in which a metallic plate processed by metal rolling is to be a banded shape and the endless belt is resulted by welding both of the ends of the banded metallic plate in another method in which a metallic pipe is formed, by metal rolling and the thin endless belt is resulted by enlarging the diameter of a loop of the metallic pipe, and so on. The endless belt produced with metal rolling is called as a seamless metallic belt or the like in view of no joint line like end-welding.
In the aforementioned conventional producing method, however, the following disadvantages are listed. Disadvantages of the producing method with end-welding for the banded metallic plate.
In the producing method with end-welding for the banded metallic plate, the mechanical strength of a welded portion is reduced to approximately 50-70% as compared with another portions of the main body. Thereby allowing disadvantages in which the welded portion becomes expanded (necking) with the use, and further, degradation, weld crack, rupture and so on easily appear by repeatedly bending.
In order to ensure long-lasting use of the endless belt with end-welding, it is required that the diameter of rollers run thereon with the endless belt is defined as more than 1,000 times of the thickness of the endless belt, curvature radius is defined to be larger so as not to concentrate large force on the welded portion, and so on. As a result, a disadvantage in which a device using the endless belt is not allowed to be small sized.
On the endless belt with end-welding, the welded portion becomes changed as compared with another portions of the main body and brought about necking over time even on the mirror finished belt, resulting in a disadvantage of faulty appearance, such as optical anisotropy and the like.
Disadvantages of the producing method with pipe metal rolling
In the producing method with pipe-metal rolling, there is a disadvantage of need of a large special apparatus in the manufacture.
In view of manufacturing with metal rolling of the pipe, there is a disadvantage in which it is difficult that the dimemsional accuracy of the thickness of the belt and the like is increased, particularly, it is seriously difficult that all the circumferential length of the belt is produced in high accuracy.
It is an object of the present invention to provide a method for producing a seamless metallic belt without a welded line and capable of being easily produced in high accuracy.
SUMMARY OF THE INVENTION
The present invention is a method for producing a seamless endless metallic belt formed out of thin-plane shaped metallic material, which is characterized by the step of cutting an outer circumferential face of a seamless belt material to create a thickness of the belt as a whole.
In the present invention as described above, the belt material is made thinner by cutting the outer circumference of the metal-made belt material of a pipe-shape or the like, thus obtaining an endless belt.
The endless belt is a seamless belt, because there is no seam on the original belt material.
In the process the outer circumference of the belt material is rotating-cut while the inner circumference is retained in a perfect circle or in similar ways, thereby allowing thickness to be controlled with high accuracy.
The circumferential length of the seamless belt has a dependence on the whole circumferential length of the belt material with high accuracy in the stage of the belt material. The inner circumferential length of the belt material is precisely found by cutting the inner circumferential face of the belt material. Therefore, the whole circumferential length of the seamless belt is also controlled with high accuracy.
In view of above description, the seamless metallic belt having an accurate thickness and along its complete circumferential length without a seam is obtained.
When the belt material is cut, it is advisable to place the belt material on an outer circumference of a core shaped so that the outer circumference is a tubular face and the outer diameter is a predetermined length smaller than the inner diameter of the belt material. The core is thermally expanded to cause an inner circumference of the belt material to contact the outer circumference of the core with pressure. Then, the outer circumferential face of the belt material is cut to create the constant thickness of the belt as a whole while the above process is maintained. Finally, the belt material is removed from the core by cooling and shrinking the core after the cutting process.
As a result, the belt material of a predetermined length can be certainly held by using the thermal expansion and shrinkage of the core (namely, “tight-fit”).
Insofar as the core is formed from a homogeneous material to have the outer circumference in the shape of a perfect circle with high accuracy, the roundness of the outer circumferential face is maintained even when the core thermally expands.
This allows the inner circumference of the belt to be maintained in the perfect circle with high accuracy in the process that the belt material is cut, the structure and the placing process to be simple, and the accurate thickness to be achieved.
It is advisable that the material used to form the belt is any one of stainless steel, carbon steel, precipitation hardening type steel and titanium alloy.
When the above materials are used as the required high-function belt, effect of the present invention sufficiently comes into play.
It is advisable that the belt material is initially shaped by using any one of the following processes extrusion molding, pultrusion molding, casting, centrifugal casting and forging.
In view of the aforementioned processes, the even belt material without any seam on the whole circumference can be obtained, thus further improving quality of the seamless metallic belt produced by using the present invention.
It is advisable that the belt material has a thickness from 50 micron to 2 mm after the cutting process.
REFERENCES:
patent: 1332592 (1920-03-01), Baker
patent: 3685475 (1972-08-01), Banks, Jr.
patent: 3986654 (1976-10-01), Hart et al.
patent: 57-163750 (1982-10-01), None
patent: 61-180631 (1986-08-01), None
patent: 6-50391 (1994-02-01), None
Patent Abstracts of Japan. vol. 013, No. 399 JP 01-142021, Jun. 2, 1989 (1 page).
Patent Abstracts of Japan. vol. 006, No. 186 JP 57-101615, Jun. 24, 1982 (1 page).
Fujii Atsushi
Funaki Akira
Matsuzawa Kouzaburo
Echols P. W.
Flynn ,Thiel, Boutell & Tanis, P.C.
Idemitsu Petrochemical Co. Ltd.
LandOfFree
Method for producing a seamless metallic belt does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing a seamless metallic belt, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing a seamless metallic belt will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2558994