Stretchable belt conveyor system and belt construction

Claim 2

A stretchable conveyor belt comprising an elongated body of elastomeric material adapted for installation on a conveyor having a belt path of a predetermined length, said belt having a length in the molded condition of not more than 95 percent of said predetermined length of said belt path, a reinforcing layer in said belt, said layer containing longitudinally extending reinforcing cords, said longitudinally extend-ing reinforcing cords having a crimped configuration in the molded condition of said belt to provide for stretching of the belt at least 5 percent during installation, said longitudinally extending reinforcing cords being substantially straightened in response to stretching of said belt to said predetermined length of said belt path upon installation on said conveyor and then having a high resistance to further elongation of the belt.

Claim 3

A stretchable conveyor belt according to claim 1 wherein said reinforcing layer includes trans-verse cords, said longitudinally extending reinforcing cords being woven between said transverse cords in the molded condition and said transverse cords being displaced by the straightening of said longitudinally extending reinforcing cords upon elongation of said belt for installation on said conveyor.

Claim 4

A stretchable conveyor belt according to claim 2 wherein said transverse cords are in substan-tially the same plane in the molded condition of the belt and at least some of said cords are displaced out of said plane by the straightening of said longitudinally extending reinforcing cords.

Claim 5

A stretchable conveyor belt according to claim 3 wherein said reinforcing layer includes longitu-dinally extending positioning cords for locating said longitudinally extending reinforcing cords in the molded condition of said belt and said positioning cords having a breaking point less than the breaking point of said reinforcing cords permitting the displace-ment of said transverse cords by said longitudinally extending reinforcing cords in response to stretching of said belt in an amount exceeding the breaking point of said positioning cords and below the breaking point of said reinforcing cords so that said reinforcing cords may be substantially straightened out after installation of the belt on the conveyor.

Claim 6

A stretchable conveyor belt according to claim 4 wherein said reinforcing layer is of square woven fabric.

Claim 7

A conveyor belt according to claim 4 wherein said longitudinally extending reinforcing cords are of high strength polyester having a high modulus of elasticity and spaced at about sixteen ends per inch, said positioning cords being of low strength nylon or cotton with a maximum 6 percent elongation and a breaking strength of not more than one hundred pounds per inch of the layer with said transverse cords being of polyester fill material spaced at about seven ends per inch.

Claim 8

A conveyor belt according to claim 4 wherein said longitudinally extending positioning cords are stretched beyond the breaking point at not more than 6 percent elongation of the belt.

Claim 9

A load-carrying belt conveyor system comprising support rollers positioned at longitudinally spaced-apart locations on said system defining a belt path, said belt path having a predetermined length, a stretchable molded conveyor belt of elastomeric material installed on said system along said belt path, said belt having a length in the molded condition of not more than 95 percent of said predetermined length of said belt path, a reinforcing layer in said belt, said layer containing longitudinally extending reinforcing cords, said longitudinally extending reinforcing cords having a crimped configuration in the molded condition of said belt to provide for stretching of the belt at least 5 percent during installation, said longitudinally extending reinforcing cords being substantially straightened in response to stretching of said belt to said predeter-mined length of said belt path upon installation on said conveyor system and then having a high resistance to further elongation of the belt.

Claim 10

A load-carrying belt conveyor system comprising support rollers positioned at longitudinally spaced-apart locations on said system defining a belt path, said belt path having a predetermined length, a stretchable molded conveyor belt of elastomeric material installed on said system along said belt path, said belt having a length in the molded condition of not more than 95 percent of said predetermined length of said belt path, a reinforcing layer in said belt, said layer containing longitudinally extending reinforcing cords, said longitudinally extending reinforcing cords having a crimped configuration in the molded condition of said belt to provide for stretching of the belt at least 5 percent during installation, said longitudinally extending reinforcing cords being substantially straightened in response to stretching of said belt to said predeter-mined length of said belt path upon installation on said conveyor system and then having a high resistance to further elongation of the belt.

Claim 11

A load carrying belt conveyor system according to claim 8 wherein said reinforcing layer of said conveyor belt contains spaced-apart transverse cords, said longitudinally extending reinforcing cords being woven between said transverse cords in the molded condition and said transverse cords being displaced by the straightening of said longitudinally extending reinforcing cords upon elongation of said belt after installation on said conveyor.

Claim 12

A load carrying belt conveyor system according to claim 9 wherein said transverse cords of said conveyor belt are in substantially the same plane in the molded condition of the belt and at least some of said transverse cords are displaced from said plane by the straightening of said longitudinally extending reinforcing cords.

Claim 13

A load carrying belt conveyor system according to claim 10 wherein said reinforcing layer of said belt contains longitudinally extending position-ing cords for locating said longitudinally extending reinforcing cords in the molded condition of said belt and said positioning cords having a breaking point less than the breaking point of said reinforcing cords for permitting the displacement of said transverse cords by stretching said belt beyond the breaking point of said positioning cords but below the breaking point of said reinforcing cords prior to or during installation of the belt on said conveyor so that said reinforcing cords will be substantially straightened out after installation of the belt on the conveyor.