Conveyor belt apparatus

Claim 2

Apparatus for detecting cracks in a conveyor belt comprising rubber magnets coupled to a conveyor belt, magnetically conducting means coupled to the conveyor belt and covering said rubber magnets to effectively magnetically short circuit said rubbEr magnets; and detector means adjacent the belt for detecting the external magnetic field generated by said rubber magnets.

Claim 3

Apparatus for detecting cracks in a conveyor belt comprising magnetic means coupled to a conveyor belt, magnetically conducting means coupled to the conveyor belt and associated with said magnetic means to effectively magnetically short circuit said magnetic means; and detector means adjacent the belt for detecting the external magnetic field generated by said magnetic means, wherein said magnetic means are comprised of a mixture of rubber and ferrite materials, and said magnetically conducting means is of an iron material.

Claim 4

Apparatus for detecting cracks in a conveyor belt comprising magnetic means coupled to a conveyor belt, magnetically conducting means coupled to the conveyor belt and associated with said magnetic means to effectively magnetically short circuit said magnetic means; and detector means adjacent the belt for detecting the external magnetic field generated by said magnetic means, wherein said magnetic means are comprised of a mixture of rubber and ferrite materials, and said magnetically conducting means is of an iron material.

Claim 5

Apparatus as in claim 2 wherein said magnetic means are comprised of a plurality of individual magnets transversely positioned with respect to the belt and longitudinally spaced from each other, and said magnetically conducting means are comprised of a plurality of individual magnetic plates each positioned over one of said magnets.

Claim 6

Apparatus as in claim 3 wherein said magnets and plates are embedded within the belt.

Claim 7

Apparatus as in claim 3 wherein each of said individual magnets and magnetic plates associated therewith are further comprised of elements thereof arranged in staggered relationship wherein adjacent ones of said elements are longitudinally spaced and transversely overlapped.

Claim 8

Apparatus as in claim 5 wherein said staggered relationship forms a zigzag arrangement.

Claim 9

Apparatus as in claim 5 wherein said staggered relationship forms a stepwise arrangement.

Claim 10

Apparatus as in claim 3 wherein said detector means is positioned transversely with respect to the belt.

Claim 11

Apparatus as in claim 3 wherein the width of each of said magnetic plates is less than twenty millimeters. The thickness of said magnetic plate is between 0.3 mm and 1.5 mm and the length of said plates is less than 185 mm plus 335 times the thickness thereof.

Claim 12

Apparatus as in claim 2 wherein said detector means comprises first and second detectors positioned colinearly and transverse to the belt, each producing a signal proportional to the magnetic field detected, and comparison means for comparing the signals from said detectors and producing an output when said signals are unequal.

Claim 13

Apparatus as in claim 2 wherein said detector means comprises first and second auxiliary detectors positioned colinearly and transverse to the belt and each producing an auxiliary signal upon detecting a magnetic field, first and second main detectors positioned colinearly transverse to the belt and longitudinally spaced from said auxiliary detectors and each producing a main signal proportional to the magnetic field detected, and comparison means for comparing said main signals and producing an output related to the difference of said main signals only when said auxiliary signals are simultaneously produced.

Claim 14

Apparatus as in claim 11 wherein said comparison means further comprises: first gating means producing an output at the simultaneous occurrence of said auxiliary signals, multivibrator means actuated by said first gating output and producing an enabling signal, difference detection means for obtaining the difference between said main signals and producing a difference signal, second gating means enabled by said enabling signal to pass said difference signal, and an output control circuit triggered by the differnce signal from said gating means and providing a detection output.

Claim 15

Apparatus as in claim 11 wherein said comparison means further comprises: first and second multivibrator means each triggered respectively by the outputs of said first and second auxiliary detectors and producing respectively a first and second inhibit pulse, pulse generating means producing a pulse output, first and second gating means for passing said pulse output in the absence of said respective first and second inhibit pulses, first and seCond modulating means receiving said pulse output respectively from said first and second gating means and respectively modulating thereon said main signals, first and second filter means receiving the modulated signals and each producing a pulse signal related to the modulated signal and a detection signal related to the modulating signal, difference detection means for producing a difference signal related to the differene between the detection signals from said first and second filter means, pulse detection means for comparing the pulse signals from said first and second filter means and producing a disabling signal, third gating means for passing said difference signal in the absence of said disabling signal, and output control means triggered by the difference signal from said third gating means and providing a detection output.

Claim 16

In a conveyor belt system comprising a conveyor belt, pulley means and driving means apparatus for detecting cracks in said belt, said apparatus comprising: rubber magnets coupled to said belt, magnetically conducting means coupled to the conveyor belt and covering said rubber magnets to effectively magnetically short circuit said rubber magnets, and detector means adjacent the belt for detecting the external magnetic field generated by said magnetic means and stopping said driving means.

Claim 17

In a conveyor belt system comprising a conveyor belt, pulley means and driving means apparatus for detecting cracks in said belt, said apparatus comprising: rubber magnets coupled to said belt, magnetically conducting means coupled to the conveyor belt and covering said rubber magnets to effectively magnetically short circuit said rubber magnets, and detector means adjacent the belt for detecting the external magnetic field generated by said magnetic means and stopping said driving means.