Patent Publication Number: US-6986419-B2

Title: Reinforcing band for conveyor belts, and conveyor belt using the same

Description:
PRIORITY CLAIM 
   This is a continuation-in-part application of U.S. application Ser. No. 10/312,976, filed Feb. 19, 2003 now U.S. Pat. No. 6,837,366, which is a 35 U.S.C. §371 national phase conversion of International Application No. PCT/JP01/05019, filed Jun. 13, 2001, which claims priority to: Country: Japan, Application No. 2000-193791, Filed: Jun. 28, 2000. 

   BACKGROUND OF THE ART 
   The present invention relates to a reinforcing band for conveyor belts and a conveyor belt using the same. 
   In a tubular belt conveyor in which an endless flat belt is partially wound to form a tube in which loads are put and conveyed, long use decreases the quality of the belt to break the tubular form and cause twisting so as to open a closed portion, so that loads are likely to escape therefrom. 
   To prevent such accident, a known conveyor belt, especially a tubular conveyor belt, includes various cores and reinforcing bands. 
   Canvases are generally used as cores or reinforcing bands in such a known belt. In a known canvas, a weft is meandered to provide lateral elasticity, so that it is likely to deviate in a direction perpendicular to a running direction of the belt when the belt is used, thereby decreasing lateral rigidity of the belt to involve decrease in shape maintenance function. 
   It is suggested that rigid cords such as wires are embedded longitudinally of a belt. If they are embedded longitudinally of the belt, running resistance of the belt is increased when a tension roller runs. If they are embedded transversely of the belt, a number of correction rollers are likely to deviate longitudinally of the belt when they pass. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing disadvantages in the prior art, it is an object to provide a durable reinforcing band of a conveyor belt and a conveyor belt having it, especially a tubular conveyor belt, in which rigid cords are provided transversely of the belt to increase lateral rigidity and shape maintenance capability of the belt and to prevent the rigid cords from deviating longitudinally of the belt. 
   According to the present invention, the foregoing disadvantages are solved below. 
   In a reinforcing band of a conveyor belt, a plurality of rigid cords spaced from each other transversely are woven together with a plurality of warps not to deviate them longitudinally. 
   In manufacturing of the conveyor belt, the reinforcing band is provided longitudinally of the belt, so that a plurality of rigid cords are provided transversely of the belt to increase lateral rigidity and shape maintenance capability of the belt. In addition, the warps are woven with the rigid cords to prevent the rigid cords from deviating longitudinally of the belt when the belt passes on the guide roller. 
   In manufacturing of the tubular conveyor belt, the reinforcing band is provided longitudinally of the belt, so that a plurality of rigid cords are directed transversely of the belt. When the belt is rolled up into a tubular shape, the rigid cords are formed as ribs to keep the tubular shape for a long time and the rigid cores are made to have the same pitch by the warps, thereby preventing the rigid cords from deviating longitudinally of the belt when the belt passes through the correction rollers. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the present invention will become more apparent from the following description with respect to embodiments as shown in accompanying drawings wherein: 
       FIG. 1  is a partially cut-away perspective view of one embodiment of a conveyor belt according to the present invention; 
       FIG. 2  is a partially cut-away perspective view of one embodiment of a tubular conveyor belt according to the present invention; 
       FIG. 3  is a vertical sectional view showing the fabric structure of a reinforcing band of a conveyor belt according to the present invention; 
       FIG. 4  is a vertical sectional view showing another embodiment of the fabric structure of a reinforcing band; 
       FIG. 5  is a perspective view showing one embodiment of how to weave the reinforcing band; 
       FIG. 6  is a vertical sectional view showing that thin rubber layers are formed on the upper and lower surfaces of the reinforcing band; and 
       FIG. 7  is a view as in  FIG. 1 , of another embodiment of a conveyor belt according to the present invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Embodiments of the present invention will be described with respect to accompanying drawings as below. 
     FIG. 1  is a partially cut-away perspective view of an embodiment of a conveyor belt according to the present invention, and  FIG. 2  is a partially cut-away perspective view of another embodiment of a conveyor belt according to the present invention. 
   In belts  1 , 1 ′, on the lower surface of a core  2  in which a plurality of canvases are laminated, a slightly narrower reinforcing band  3  is overlapped. In a tubular belt conveyor in  FIG. 2 , the reinforcing band  3  is supported by a pair of thickness-adjusting breakers  4 , and these elements are surrounded by rubber  5 . 
   In the reinforcing band  3 , a plurality of rigid cords  6  spaced from each other are provided transversely with respect to a longitudinal direction of the belts  1 ,  1 ′, and a plurality of warps are woven with the rigid cords  6  so that the warps are not to move longitudinally. 
   The rigid cords  6  may be made of synthetic fibers, aramid fibers or steel to provide rigidity, flexibility and elasticity enough to keep its shape when the belt  1  is rolled up into a trough or pipe. 
   The warps  7  may be made of synthetic fibers or aramid fibers which have smaller diameter than that of the rigid cord  6 . 
   As shown in  FIG. 3 , the warp  7  is wound on the rigid cord  6  which serves as a weft at an intersection to tie a single knot  8 , or as shown in  FIG. 4 , the rigid cord  6  is held between two knots  9 ,  10  of the warp  7 . 
     FIG. 5  illustrates how to weave the reinforcing band  3  in detail. In this example, a plurality of warps  7  are twisted on rigid cords  6  as wefts by guide bars  11  and hooks  13  with covers  12  so that the rigid cords  6  may be straight lines. 
   By such a fabric structure, each of the rigid cords  6  is prevented from deviating in a longitudinal direction of the reinforcing band  3 . 
     FIG. 6  shows that the reinforcing band  3  formed as above is tightened in a longitudinal direction. Thin band-like rubber layers  14 ,  15  are pressed by two pairs of upper and lower pressing rollers  16 ,  16  and bonded by adhesive (not shown). Each surface of the reinforcing band  3  is covered with the rubber layers  14 ,  15 . Thus, when the core  2  is put on the reinforcing band  3  and held by the rubber layer  15  to form the belts  1 ,  1 ′, the relationship between the rigid cord  6  and the warp  7  is not broken to facilitate manufacturing and improve quality. 
   The formation of the rubber layers  14 ,  15  on each surface of the reinforcing band  3  is not limited to bonding as above, but another way such as vulcanization is also applicable. 
     FIG. 7  shows an embodiment in which the reinforcing band  3  is arranged between a first belt core  2  and a second belt core  2 ′. This provides a symmetrical belt structure in the thickness direction which allows the belt to have uniform strength whether it is rolled-up upwardly or downwardly. A conveyor belt constructed in this manner allows materials to be transported reciprocally in a rolled-up tubular belt. 
   In this embodiment, even if the belt suffers from deterioration or damage on one side, the other side can be used to transport materials in order to prevent the deterioration or damage from becoming worse. Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.