Abstract An apparatus for measuring the thickness of travelling sheet materials employs a pair of linear displaceable transducers which are disposed in aligned opposition so their respective sensors contact the opposite side of the sheet material, with the sensors mounted so they can ''''float'''' with the material to compensate for vibration or movement while maintaining a separation equal to its thickness. Each transducer output is the analog of the displacement of its sensor from a zero position and these analogs can be combined to produce a difference output which is directly proportional to the instantaneous material thickness between the two sensors. The output signal can operate a visual display or recorder indicating the thickness dimension of the sheet material at all times.
A floating roller thickness monitoring device for webs of sheet material under transport conditions that cause oscillations in such webs comprising: a caliper frame having spaced extending arms so the distal ends thereof will extend about and below a portion of an edge of a web under transport conditions so such edge will pass continuously therebetween; a base mounting said caliper frame normal to the direction of travel of such edge of the web under transport conditions, said base including releasable catch means operable to allow said caliper frame to swing clear of such edge when such edge exerts a force greater than a predetermined value on any part of said monitoring device; separate mounting means adjacent to said distal end of each of said arms, each said mounting means including micrometer adjusted means; a separate transducer mounted in each of said mounting means in an opposed relationship and adjustable through said micrometer adjusted means, each of said transducers having a linearly movable sensor element oriented in said transducer in aligned opposition with said movable sensor element of said other transducer whereby they reciprocate along on a common axis, each of said sensor elements having a roller at its inboard end with key means operablE to orient said roller to properly track on such edge of a web under transport conditions, each of said sensor elements also having biasing means urging it in the direction of the other sensor element whereby said rollers will positively track on opposite surfaces of said edge between said distal ends of said arms, separate transducer means associated with each of said sensor elements operable to produce an electrical signal proportional to a displacement of its associated sensor element; circuit means connected to said transducer means having a summing circuit operable to add said signals and an averaging circuit operable to average instantaneous outputs from said summing circuit over a settable period of time; and meter means connected to said averaging circuit operable to visually display the average separation of said rollers whereby the average thickness of a web under transport can be continuously monitored and said rollers will be swung free of said web if said web exerts an unduly large force thereon.
Claim 2
Dependent Claim
369 words
A floating roller thickness monitoring device for webs of sheet material under transport conditions that cause oscillations in such webs comprising: a caliper frame having spaced extending arms so the distal ends thereof will extend about and below a portion of an edge of a web under transport conditions so such edge will pass continuously therebetween; a base mounting said caliper frame normal to the direction of travel of such edge of the web under transport conditions, said base including releasable catch means operable to allow said caliper frame to swing clear of such edge when such edge exerts a force greater than a predetermined value on any part of said monitoring device; separate mounting means adjacent to said distal end of each of said arms, each said mounting means including micrometer adjusted means; a separate transducer mounted in each of said mounting means in an opposed relationship and adjustable through said micrometer adjusted means, each of said transducers having a linearly movable sensor element oriented in said transducer in aligned opposition with said movable sensor element of said other transducer whereby they reciprocate along on a common axis, each of said sensor elements having a roller at its inboard end with key means operablE to orient said roller to properly track on such edge of a web under transport conditions, each of said sensor elements also having biasing means urging it in the direction of the other sensor element whereby said rollers will positively track on opposite surfaces of said edge between said distal ends of said arms, separate transducer means associated with each of said sensor elements operable to produce an electrical signal proportional to a displacement of its associated sensor element; circuit means connected to said transducer means having a summing circuit operable to add said signals and an averaging circuit operable to average instantaneous outputs from said summing circuit over a settable period of time; and meter means connected to said averaging circuit operable to visually display the average separation of said rollers whereby the average thickness of a web under transport can be continuously monitored and said rollers will be swung free of said web if said web exerts an unduly large force thereon.