Vacuum operated switch construction

Claim 1

A VACUUM OPERATED SWITCH COMPRISING THREE ELECTRICALLY INSULATING RIGID CASING MEANS ARRANGED IN ALIGNED RELATION AND DEFINING A COMPARTMENT BETWEEN EACH PAIR OF ADJACENT CASING MEANS, A PAIR OF FLEXIBLE DIAPHRAGMS RESPECTIVELY DISPOSED BETWEEN EACH PAIR OF ADJACENT CASING MEANS A DIVIDING SAID COMPARTMENTS INTO FOUR CHAMBERS, SAID DIAPHRAGMS RESPECTIVELY BEING ELECTRICALLY CONDUCTIVE AND CARRYING SWITCH CONTACTS RESPECTIVELY DISPOSED IN TWO OF SAID CHAMBERS, EACH DIAPHRAGM HAVING AN OUTWARDLY EXTENDING PERIPHERAL PROJECTION, SAID CASING MEANS HAVING PASSAGE MEANS RESPECTIVELY LEADING TO SAID TWO CHAMBERS AND BEING ADAPTED TO BE INTERCONNECTED TO A VACUUM SOURCE, SAID CASING MEANS CARRYING SWITCH CONTACTS RESPECTIVELY DISPOSED IN SAID TWO CHAMBERS, AND TERMINAL MEANS ELECTRICALLY AND RESPECTIVELY INTERCONNECTED TO SAID SWITCH CONTACTS AND BEING ADAPTED TO BE CONNECTED TO LEADS EXTERIORLY OF SAID CASING MEANS, TWO OF SAID TERMINAL MEANS BEING RESPECTIVELY SECURED TO SAID PROJECTIONS OF SAID DIAPHRAGMS AT POINTS INTERMEDIATE THE INNER AND OUTER SURFACES OF SAID CASING MEANS BY OVERLAPPING SAID PERIPHERAL PORTIONS AND HAVING FASTENING MEANS DIRECTLY FASTENING SAID OVERLAPPING PORTIONS TOGETHER.