Pneumatic thickness sensor head

Claim 1

A pneumatic sensor head for monitoring the thickness of a continuously moving sheet of material passing therethrough, comprising: a. first and second blocks having respective first and second aligned nozzles separated by a distance sufficient to receive the sheet of material passing therethrough; b. means for admitting pressurized fluid to said first and second nozzles to sense an average variation in the back pressure therefrom proportional to a change in the thickness of the sheet of material being monitored; c. a plurality of removable stacked laminated sheets positioned between said first and second blocks for adjusting the distance between said first and second nozzles, whereby to enable optimum operation of said sensor head over wide variations in nominal thicknesses of monitored sheets of material, each of said laminated sheets having a hole therethrough in alignment with the hole in an adjacent one of said laminated sheets to form a passageway therein; and d. said admitting means comprising passageway means within said first block, passageway means and a port within said second block and said passageway formed within said stacked laminated sheets, said passageway within said first block being fluidically connected between said first nozzle and said passageway formed within said stacked laminated sheets, and said passageway means within said second block being fluidically connected to said second nozzle, said port and said passageway formed within said stacked laminated sheets.