Metal gaskets

Claim 1

A GASKET FORMED OF TWO COMPLEMENTARY PLANAR PLIES OF THIN FLEXIBLE RESISTANTLY RESILIENT SHEET METAL HAVING REGISTERING SERVICE OPENING THERETHROUGH, EACH PLY HAVING A PLANAE FLANGE PORTION IMMEDIATELY ADJACENT TO AND SURROUNDING CERTAIN OF SAID SERVICE OPENING AND BENT UP OUT OF THE PLANE OF THE PLY AT AN OBTUSE ANGLE WITH RESPECT TO SUCH PLANE, SAID PLANAR FLANGE PORTIONS OF THE TWO PLIES SURROUNDING SAID SERVICE OPENINGS BEING COMPLEMENTARY AND PROJECTING IN OPPOSITE DIRECTION AWAY FROM THE COMBINED PLANE OF THE PLIES AND TOWARD THE SAID SERVICE OPENINGS, EACH OF SAID FLANGE PORTIONS BEING RESISTINGLY RESILIENT AND YIELDABLE TO BE BROUGHT INTO BACKTO-BACK PLANAR ENGAGEMENT WITH ITS COMPLEMENTARY FLANGE PORTION WITHIN THE COMBINED PLANE OF THE TWO PLIES, A HEAT RESISTANT PLASTIC COATING COVERING THE OPPOSED SURFACES OF THE TWO PLIES, SAID TWO PLIES BEING SECURED TOGETHER BACK-TO-BACK AT SPACED APART POINTS IN PROXIMITY ONLY TO THE OUTER PERMIETER OF THE GASKET SPACED FROM THE PLANAR FLANGE PORTIONS OF THE TWO PLIES, AND SAID TWO PLIES BEING FREE FROM EACH OTHER THROUGHOUT THE ENTIRE AREA THAT INCLUDES THE SERVICE OPENINGS AND THE FLANGE PORTIONS THEREABOUT WITH THE PLANAR FLANGE PORTIONS OF ONE PLY BEING FREE FROM THE COMPLEMENTARY FLANGE PORTIONS OF THE OTHER PLY TO MOVE AND RESPOND INDEPENDENTLY THEREOF AND WITHOUT RESTRAINT BY THE OTHER PLY EXCEPT AS THE SAME IS RESTRAINED BY SAID POINTS OF SECUREMENT OF THE TWO PLIES TOGETHER.