Apparatus and method for thickness detection

An apparatus for detecting a change in thickness of a strip of material, the strip of material having a first face and a second face opposite of the first face with the thickness of the material disposed therebetween, the apparatus comprising:

• a detection element comprising:
• a light source;
• a light detector;
• and
• an indicator communicably coupled with the light detector;
• a sending cable comprising a plurality of optical fibers each having a first end and a second end and configured for receiving light from the light source and transmitting it toward the strip of material;
• a receiving cable comprising a plurality of optical fibers each having a first end and a second end and configured for receiving a portion of light output by the sending cable and reflected off of the first or second face of the strip of material then transmitting the reflected light to the light detector;
• and
• a housing configured for fixing the second ends of the optical fibers of the sending and receiving cables in spaced, side-by-side relationship with each other in alternating succession, wherein the housing is configured for shaping and focusing light fields extending from the second ends of the optical fibers of the sending cable and receiving fields of the second ends of the optical fibers of the receiving cables, wherein the housing is configured to limit movement of the strip of material toward and away from the second ends of the optical fibers in the direction of the thickness of the strip of material such that an amount of light reflected off of the strip of material into the receiving cable is inversely proportional to the thickness of the strip of material,
• wherein the indicator is configured to automatically actuate from a first state to a second state when the amount of light sent to the light detector is below a threshold of tolerance,
• wherein the optical fibers of the sending cable are divided into a first subset and a second subset and the optical fibers of the receiving cable are divided into a first subset and a second subset,
• wherein the optical fibers of the first subset of the sending cable are arranged in alternating succession with the optical fibers of the first subset of the receiving cable and are configured to direct light onto the first face of the strip of material,
• wherein the optical fibers of the second subset of the sending cable are arranged in alternating succession with the optical fibers of the second subset of the receiving cable and are configured to direct light onto the second face of the strip of material.

A method of determining an increase in the thickness of a strip of material, the method comprising:

• directing light from a first subset of optical fibers of a sending fiber optic cable toward a first face of the strip of material;
• directing light from a second subset of optical fibers of the sending cable toward a second face of the strip of material which is opposite of the first face of the strip of material;
• receiving with a first subset of optical fibers of a receiving fiber optic cable a portion of light reflected off of the first face of the strip of material, wherein the first subset of optical fibers of the receiving cable have ends positioned substantially side-by-side and spaced in alternate succession with ends of the first subset of optical fibers of the sending cable;
• receiving with a second subset of optical fibers of the receiving cable a portion of light reflected off of the second face of the strip of material, wherein the second subset of optical fibers of the receiving cable have ends positioned substantially side-by-side and spaced in alternate succession with ends of the second subset of optical fibers of the sending cable;
• detecting with a light detector a total amount of light received by the first and second subsets of the receiving cable;
• and
• outputting an indicator signal to a user or an automated system if the amount of light detected is below the threshold of tolerance.