Mounting arrangement for coil bobbins

Claim 1

IN AN ELECTROMAGNETIC DEVICE, A BOBBIN FORMED OF MOLDED INSULATING MATERIAL HAVING A CYLINDRICAL PORTION WITH A SPOOL HEAD AT EACH END THEREOF FORMING A WINDING SPACE FOR A COIL WINDING, A CYLINDRICAL OPENING EXTENDING THROUGHOUT THE LENGTH OF SAID CYLINDRICAL PORTION AND BEING TAPERED FROM ONE POINT IN THE LENGTH THEREOF TOWARD ONE END THEREOF SO THAT THE OPENING IS SMALLER AT ONE END THAN AT THE OTHER, A MAGNETIC CORE HAVING A THREADED HOLE IN ONE END THEREOF AND A KNURLED PORTION ADJACENT THE OTHER END THEREOF, A HEELPIECE HAVING A BENT UP SECTION AT ONE END THEREOF OF A CERTAIN SUBSTANTIALLY TRIANGULAR SHAPE WITH A CLEARANCE HOLE THEREIN, ONE OF THE SPOOL HEADS OF SAID BOBBIN HAVING A FORMED OUT DEPRESSED PORTION CONFORMING IN SHAPE EXACTLY TO THE SHAPE OF SAID BENT UP SECTION OF THE HEELPIECE, SAID CORE BEING DRIVEN INTO SAID CYLINDRICAL OPENING FROM THE LARGER END THEREOF WITH A FORCE FIT INTO SAID TAPERED PART OF THE OPENING UNTIL THE END OF THE CORE WITH THE THREADED OPENING IS FLUSH WITH THE BOTTOM OF SAID DEPRESSED PORTION, SAID BENT UP SECTION OF SAID HEELPIECE THEN INSERTED INTO SAID DEPRESSED PORTION WITH A SCREW INSERTED THROUGH THE CLEARANCE HOLE IN THE HEELPIECE AND THREADED TIGHTLY INTO THE THREADED HOLE IN THE CORE, SAID CORE, HEELPIECE AND BOBBIN BEING RIGIDLY HELD AGAINST RELATIVE MOVEMENT BY MEANS OF SAID FORCE FIT OF THE CORE AND SAID DEPRESSED PORTION OF THE BOBBIN.