Lamp base and terminal structure

Claim 1

A BASE FOR ATTACHMENT BY BASING CEMENT TO THE OUTER END PORTION OF AN I-SHAPE EXTERNAL PINCH SEAL OF A VITREOUS ENVELOPE OF AN ELECTRIC LAMP DEVICE, SAID BASE COMPRISING AN INSULATOR AND A CUP-LIKE CYLINDRICAL METAL SHELL FOR ACCOMMODATING THE SAID PINCH SEAL PORTION, SAID SHELL HAVING AN I-SHAPED SLOT AT ONE END FOR MAKING A SNUG FIT WITH THE SEAL AND A CYLINDRICAL SIDE WALL HAVING AN INNER DIAMETER CLOSELY APPROACHING THE WIDTH OF THE SEAL, SAID INSULATOR BEING OF GENERALLY CYLINDRICAL SHAPE HAVING AT ONE END A DIAMETRAL SLOT PROVIDING A SEAT FOR THE SEAL, THE SLOTTED END OF THE INSULATOR EXTENDING INTO THE RIM PORTION OF SAID CUP-LIKE SHELL AND DEFINING WITH SAID SHELL A PINCH SEAL AND BASING CEMENT ACCOMMODATING SPACE, SAID INSULATOR HAVING AN OUTWARDLY EXTENDING HOLLOW STEM COMMUNICATING WITH SAID SLOT AND BEING OF REDUCED DIAMETER AND TAPERING AT ITS OUTER END, SAID BASE COMPRISING ALSO A THREADED METAL SHELL CONTACT AFFIXED TO SAID STEM ADJACENT THE SLOTTED END OF THE INSULATOR AND A METAL EYELET CONTACT AFFIXED TO THE SMALLER DIAMETER END OF THE TAPERED PORTION OF THE STEM, THE WALL OF SAID STEM HAVING LEAD-IN WIRE ACCOMMODATING OPENINGS AT SAID CONTACTS.