Method of making tape-heads

Claim 1

THE METHOD OF MANUFACTURE OF A TAPE-HEAD HAVING AT LEAST TWO ELECTRO-MAGNETS COMPRISING PERFORMING IN THE ORDER CLAIMED, THE STEPS OF; PROVIDING TWO GROUPS OF POLE ELEMENTS AND TWO FIXTURE PLATES, EACH POLE ELEMENT COMPRISING A METAL STRIP AND EACH FIXTURE PLATE BEING OF FLAT RECTANGULAR FORM HAVING RECESSES IN ONE LONGITUDINAL EDGE, BENDING ONE END OF EACH POLE FACE ELEMENT AT RIGHT ANGLES TO FORM A POLE FACE LUG, RIGIDLY FIXING THE ONE SET OF ENDS OF THE POLE ELEMENTS OF EACH GROUP TO A FIXTURE PLATE, BY SECURING SAID POLE FACE LUGS IN SAID RECESSES IN THE FIXTURE PLATE SO THAT EACH POLE ELEMENT EXTENDS IN A PLANE WHICH IS SUBSTANTIALLY PARALLEL TO THE PLANE OF ITS ASSOCIATED FIXTURE PLATE, MACHINING ONE FACE OF EACH FIXTURE PLATE TO PROVIDE ACCURATELY FLAT SURFACES, PROVIDING A SET OF GAP SPACER ELEMENTS, FORMING A SUBASSEMBLY BY ASSEMBLING TOGETHER THE TWO FIXTURE PLATES AND ATTACHED POLE ELEMENTS WITH THE GAP SPACER ELEMENTS INTERPOSED BETWEEN THE FIXTURE PLATES AND THE MACHINED FLAT SURFACES OF THE FIXTURE PLATES IN ENGAGEMENT, PROVIDING A HOUSING MEMBER OF U SHAPE, THE BASE OF THE U BEING OF OUTWARDLY CONVEX FORM TO CONSTITUTE THE FRONT FACE OF THE TAPE-HEAD AND HAVING AN OPENING THEREIN, ATTACHING THE SAID SUB-ASSEMBLY TO THE HOUSING MEMBER SO THAT THE POLE ELEMENTS ARE LOCATED WITHIN THE HOUSING MEMBER AND THE FIXTURE PLATES ARE LOCATED OUTSIDE THE FRONT FACE OF THE HOUSING MEMBER, WITH EDGE PORTIONS OF THE FIXTURE PLATES ENGAGING IN SAID OPENING, PROVIDING A SCREENING PLATE ASSEMBLY OF AT LEAST ONE SCREENING PLATE, ASSEMBLING SAID SCREENING PLATE ASSEMBLY INTO THE HOUSING MEMBER TO LIE IN BETWEEN THE PAIRS OF POLE ELEMENTS WITH THE FRONT EDGES OF THE SCREENING ASSEMBLY ENGAGING THROUGH SAID OPENING IN THE FRONT FACE OF THE HOUSING MEMBER, RIGIDLY HOLDING IN THE FRONT FACE OF BINATION OF HOUSING MEMBER, SAID SUB-ASSEMBLY AND SCREENING PLATE ASSEMBLY, AND MACHINING AWAY THE MATERIAL OF THE FIXTURE PLATES AND SCREENING ASSEMBLY PROJECTING FROM THE FRONT FACE OF THE HOUSING MEMBER TO LEAVE EXPOSED POLE FACES AT THE ENDS OF THE POLE ELEMENTS FLUSH WITH THE FRONT FACE OF THE HOUSING MEMBER, PROVIDING BOTTINS HAVING WINDINGS THEREON, INSERTING ONE BOBBIN OVER EACH POLE ELEMENT WITHIN THE HOUSING MEMBER, PROVIDING LAMINATIONS FOR EACH BOBBIN, INSERTING LAMINATIONS WITHIN THE BOBBINS TO LIE ON OPPOSITE SIDES OF EACH POLE ELEMENT WITHIN A BOBBIN, BENDING THE PROJECTING ENDS OF THE LAMINATIONS INWARDS TOWARDS ONE ANOTHER AND INTERENGAGING SAME TO FORM THE COMPLETE CORES OF THE SEPARATE ELECTROMAGNETS, PROVIDING A CONTAINER HAVING AN OPEN MOUTH, A BASE, AND A PLASTICS MOULDING HAVING TERMINAL CONNECTIONS LOCATED IN SAID BASE, AND INSERTING SAID HOUSING MEMBER INTO SAID CONTAINER THROUGH SAID OPEN MOUTH AND CONNECTING THE WINDINGS ON THE BOBBINS TO SAID TERMINAL CONNECTIONS.