Measuring apparatus and method for determining the duration of the application of pressure in a rotary press

Claim 1

APPARATUS FOR MEASURING THE DURATION OF THE APPLICATION OF PRESSURE TO A PAPERMAKER''S FELT AS IT PASSES THROUGH THE NIP BETWEEN TWO ROLLERS COMPRISING, IN COMBINATION, AN ELONGATED SUBSTANTIALLY FLAT ENVELOPE OF FLEXIBLE DIELECTRIC MATERIAL, A FIRST AND A SECOND ELECTRICALLY CONDUCTIVE SWITCH ELEMENT POSITIONED IN SPACED RELATIONSHIP WITH EACH OTHER WITHIN SAID ENVELOPE, EACH OF SAID SWITCH ELEMENTS HAVING SPACED-APART CONTACT PORTIONS THEREON, INSULATING MEANS INTERPOSED BETWEEN THE CONTACT PORTIONS ON ONE OF SAID SWITCH ELEMENTS AND THOSE ON THE OTHER OF SAID SWITCH ELEMENT, SAID INSULATING MEANS INCLUDING A PAIR OF SPACED APERTURES TO ENABLE MOVEMENT OF THE CONTACT PORTIONS ON ONE OF SAID SWITCH ELEMENTS INTO SEQUENTIAL ENGAGEMENT WITH CORRESPONDING CONTACT PORTIONS ON THE OTHER SAID SWITCH ELEMENT IN RESPONSE TO THE APPLICATION OF PRESSURE GREATER THAN A PREDETERMINED PRESSURE TO SAID ENVELOPE, MEANS FOR ADVANCING SAID ENVELOPE AND SAID PAPERMAKERS'' FELT THROUGH THE NIP BETWEEN SAID ROLLERS TO MOVE CORRESPONDING CONTACT PORTIONS INTO AND OUT OF ENGAGEMENT WITH EACH OTHER, EACH OF THE CONTACT PORTIONS ON SAID ONE SWITCH ELEMENT ENGAGING THE CORRESPONDING CONTACT PORTION ON SAID OTHER SWITCH ELEMENT AT A PARTICULAR, DISCRETE POINT, MEANS RELEASABLY CONNECTED TO SAID SWITCH ELEMENTS FOR SUPPLYING AND ALTERNATING CURRENT SIGNAL THERETO, AND MEANS CONNECTED IN SERIES WITH SAID SWITCH ELEMENTS FOR DETECTING CHANGES IN THE AMPLITUDE OF SAID SIGNAL, TO ENABLE MEASUREMENT OF THE TIME AT LEAST ONE PAIR OF CORRESPONDING CONTACT PORTIONS ARE IN ENGAGEMENT AND THE TIME BETWEEN THE ENGAGEMENT OF SUCCESSIVE PAIRS OF CORRESPONDING CONTACT PORTIONS.