Conveyors: power-driven – Conveyor section – Endless conveyor
Reexamination Certificate
1998-12-14
2001-07-17
Hess, Douglas (Department: 2167)
Conveyors: power-driven
Conveyor section
Endless conveyor
C198S957000
Reexamination Certificate
active
06260692
ABSTRACT:
TECHNICAL FIELD
This invention relates to a conveyor belt reinforced by a synthetic fiber woven fabric. More particularly, the present invention relates to a conveyor belt which exhibits a small elongation in the course of its use for an extended period and is hardly damaged by foreign matters caught between pullies and a conveyor belt.
BACKGROUND ART
Woven fabrics of a nylon fiber or a polyester fiber have been used in the past as a reinforcing layer of conveyor belts.
However, the conveyor belt of this kind is likely to be damaged due to abnormal deformation that occurs when foreign matters such as a cake adhering to pullies and falling transported materials are caught between the pullies and the conveyor belt. Even though abnormal deformation is not of the level which directly results in the damage of the belt, repetition of such abnormal deformation lowers the strength of the belt due to its fatigue and consequently, the conveyor belt cannot withstand an extended use.
In the conveyor belt of this kind, elongation occurs in a longitudinal direction of the belt in the course of use of the belt, and the belt is elongated as a whole. In such a case, the length of the conveyor machine must be regulated by adjusting the stroke of a take-up device disposed in front, or at the back, of the belt conveyor machine. As this elongation proceeds further and the stroke of the take-up device cannot absorb the elongation any longer, the belt must be cut short.
Consequently, the inventors of the present invention have examined from various aspects the damage and fatigue of the conveyor belt resulting from the abnormal deformation that occurs when any foreign matters are caught between the pullies and the conveyor belt, and means for reducing the elongation of the belt that occurs in the course of use. As a result, the present inventors have found it effective to increase, as much as possible, elongation at break of a synthetic fiber woven fabric constituting a reinforcing layer of a conveyor belt in the belt longitudinal direction to cope with the breakage and the fatigue of the belt resulting from abnormal deformation, and to reduce, as much as possible, the elongation of the synthetic fiber woven fabric in the belt longitudinal direction during its use to cope with the elongation of the belt.
DISCLOSURE OF INVENTION
The present invention is completed to solve these problems of the prior art and aims at providing a conveyor belt which is difficult to be damaged even when any foreign matters are caught between pullies and a conveyor belt and which exhibits a small elongation of a belt during the use of the belt.
According to the present invention, damage and the drop of the strength hardly occur even when foreign matters such as the cake adhering to the pullies and the falling transported materials are caught between the pullies and the conveyor belt, the conveyor belt can be used for a long time, the elongation of the entire belt is small, the adjustment of the machine length is not much required and hence, the cutting-short operation of the belt is hardly necessary, and the stroke of the take-up device can be reduced. Further, the number of workers and the cost for maintenance and inspection can be reduced.
In a conveyor belt having a reinforcing layer of a synthetic fiber woven fabric embedded between an upper surface cover and a lower surface cover, the object of the present invention described above can be accomplished by a synthetic fiber woven fabric characterized in that an elongation at break of the synthetic fiber woven fabric in a belt longitudinal direction is at least 25% and an elongation at a load 10% of guarantee strength is not greater than 1.5%.
Yarns of a high elongation polyester or high elongation nylon having an elongation at break of at least 25% can be used as warps of the synthetic fiber woven fabric.
A woven fabric formed by alternately arranging one to three warps of a polyester fiber and one to three warps of a nylon fiber can be used as the synthetic fiber woven fabric described above. In this case, the elongation at break of the warps may be less than 25%.
Mix-twisted yarns of the polyester fiber and the nylon fiber can be used as the warps of the synthetic fiber woven fabric described above. A polyester having a high or normal elongation and a nylon having a high or normal elongation can be used as the fiber material in this case.
The yarns used for the synthetic fiber woven fabric are used preferably after they are treated with an adhesive solution, and the temperature of the adhesive solution for the warps in this case is preferably not lower than 200° C. The tension applied to the yarns at the time of the adhesive solution treatment, that is, a set tension, is preferably small, for example, 0.2 g/denires, and may be zero, too.
A woven fabric having a structure in which the warps and the wefts are linearly arranged and are woven by entwining them by twining yarns, that is, a so-called “unicorn fabric”, is suitable for the synthetic fiber woven fabric described above. Further, the synthetic fiber woven fabric is preferably a tyre fabric of synthetic fibers.
REFERENCES:
patent: 4154335 (1979-05-01), Burnett et al.
patent: 4226417 (1980-10-01), Camilleri
patent: 4243714 (1981-01-01), Vanassche et al.
patent: 4302197 (1981-11-01), Kimura et al.
patent: 4305433 (1981-12-01), Vanassache et al.
patent: 4449627 (1984-05-01), Kell
patent: 4504258 (1985-03-01), Tanaka et al.
patent: 4518647 (1985-05-01), Morrison
patent: 4526637 (1985-07-01), Long
patent: 4533420 (1985-08-01), Wetzel
patent: 4547422 (1985-10-01), Oliver et al.
patent: 4650068 (1987-03-01), Vanassche et al.
patent: 4682973 (1987-07-01), Fujita et al.
patent: 4823942 (1989-04-01), Martin et al.
patent: 5002178 (1991-03-01), Yamada
patent: 5004098 (1991-04-01), Marshall
patent: 5062924 (1991-11-01), McCarten
patent: 5326411 (1994-07-01), Arnold
patent: 5422165 (1995-06-01), Arnold
patent: 5460261 (1995-10-01), Kusel et al.
patent: 5595284 (1997-01-01), Takahashi et al.
patent: 5609242 (1997-03-01), Hutchins et al.
patent: 5685417 (1997-11-01), Hasegawa et al.
patent: PCT/JP97/01587 (1998-12-01), None
Fukuchi Yoshimitsu
Katsumata Shinichi
Mori Kojiro
Sashide Kazuo
Shimotashiro Yuji
Arent Fox Kintner & Plotkin & Kahn, PLLC
Hess Douglas
Yokohama Rubber Co., Ltd
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