Electric lamp base end structure

Claim 1

AN ELECTRIC LAMP COMPRISING A SEALED TUBULAR GLASS ENVELOPE PROVIDED AT ITS OPPOSITE ENDS WITH PROTRUDING FLAT STEM PRESS PORTIONS DISPOSED IN A COMMON PLANE, EACH OF SAID FLAT STEM PRESS PORTIONS HAVING SHALLOW INDENTATIONS IN ITS OPPOSITE FLAT SIDES FORMING SHARP LATERAL SHOULDERS ON THE RESPECTIVE STEM PRESS PORTIONS FACING INWARDLY OF THE ENVELOPE, LEAD-IN WIRES SEALED THROUGH RESPECTIVE ONES OF SAID STEM PRESS PORTIONS AND EXTENDING INTO SAID ENVELOPE, A FILAMENT DISPOSED WITHIN SAID ENVELOPE AND CONNECTED AT ITS OPPOSITE ENDS TO SAID LEAD-IN WIRES, SAID LEAD-IN WIRES PROTRUDING ENDWISE FROM SAID STEM PRESS PORTIONS AND BEING BENT AROUND THE OUTER ENDS THEREOF TO EXTEND ALONGSIDE ONE OF THEIR FLAT SIDES AND ACROSS THE RESPECTIVE INDENTATION THEREIN, AND HOLLOW METAL BASE SHELLS MOUNTED ON AND ENCLOSING THE RESPECTIVE STEM PRESS PORTIONS AND HAVING FLAT SIDE PORTIONS CORRESPONDING TO AND DISPOSED CLOSELY ALONGSIDE THE FLAT SIDES OF THE STEM PRESS PORTIONS, EACH OF THE FLAT SIDE PORTIONS OF SAID BASE SHELLS BEING PROVIDED WITH AN INWARD SPRING TONGUE PORTION PRESSED OUT THEREFROM AND HAVING ITS FREE END SNAP-CAUGHT WITHIN THE RESPECTIVE INDENTATION IN THE STEM PRESS BEHIND THE SAID LATERAL SHOULDER THEREOF TO LOCK THE BASE SHELL SECURELY IN PLACE ON THE STEM PRESS AGAINST ENDWISE REMOVAL THEREFROM, ONE OF THE SAID SPRING TONGUES OF EACH BASE SHELL RESILIENTLY CLAMPING THE RESPECTIVE LEAD-IN WIRE FIRMLY AGAISNT THE BOTTOM OF THE INDENTATION IN THE RESPECTIVE STEM PRESS PORTION TO THEREBY FORM A GOOD ELECTRICAL CONNECTION WITH SAID LEAD-IN WIRE.