Method of manufacturing commutator

• US 3,958,326 A
• Filed: 01/14/1975
• Issued: 05/25/1976
• Est. Priority Date: 03/13/1974
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Kobayashi, Toshihiro, Matsumoto, Kazuo
• Primary Examiner(s): Hall, Carl E.
• Application Number:
  US05/540,797
• Time in Patent Office: 497 Days
• Field of Search: 29/597, 29/418, 310/235, 310/236, 310/42
• US Class Current: 29/597
• CPC Class Codes: H01R 43/08 in which segments are not separated until after assembly
• CPC Class Codes: Y10T 29/49011 Commutator or slip ring assembly
• CPC Class Codes: Y10T 29/49799 Providing transitory integral holding or handling portion

Abstract

A method of manufacturing a commutator whereby first, a straight length of copper metal is formed into a circular commutator blank with a parallel space formed by both ends of the straight length of metal; second, the commutator blank is positioned on a lower die of an extrusion press machine in order that the parallel space of the commutator blank is aligned with a plane on which one of cutting edges of a mandrel of the extrusion press machine is placed; third, the commutator blank is extruded to form a segment ring having parallel gaps inside the segment and bridging portions formed across the outer ends of the gaps, whereby the parallel space is elongated along one of the bridging portions; fourth, the segment ring is molded with an insulating material; finally, the outer surface of the segment ring is cut to remove the bridging portions, thereby to complete the commutator.

Claims

1. A method of manufacturing a commutator comprising the steps of;

preparing a straight length of metal with two ends, each end having a first and second tapered portion;

forming said straight length of metal into a circular commutator blank, said two ends being positioned adjacent each other, thereby to form a parallel space by said first tapered portions spaced in parallel with each other and to form a locating portion by said second tapered portions;

inserting said circular commutator blank into an extrusion press having an upper and a lower die and a mandrel;

locating said locating portion of said circular commutator blank on a projection provided on said lower die, thereby to locate said parallel space in a plane in which one of a plurality of cutting edges of said mandrel is placed;

extruding said circular commutator blank, thereby to elongate the metal of said blank to form a segment ring including a flanged portion and a plurality of gaps on the inside thereof and bridging portions formed across the outer ends of said gaps, said parallel space being elongated and positioned along a line of one of said bridging portions;

cutting radially said flanged portion, thereby to divide same into individual flanged segments;

molding said segment ring with an insulating material; and

cutting the outer peripheral surface of said segment ring to remove said bridging portions thereby to complete a commutator.

2. A method of manufacturing a commutator comprising the steps of;

preparing a straight length of metal with tapered ends;

forming a locating portion on said straight length of metal;

forming said straight length of metal into a circular commutator blank, said ends being positioned adjacent and spaced in parallel with each other, thereby to form a parallel space;

inserting said circular commutator blank into an extrusion press;

locating said parallel space of said circular commutator blank by said locating portion in a plane in which one of a plurality of cutting edges of a mandrel of said extrusion press is placed;

extruding said circular commutator blank, thereby to elongate the metal thereof to form a segment ring including a plurality of parallel gaps on the inside thereof and bridging portions formed across the outer ends of said gaps, said parallel space being elongated and positioned along a line of one of said bridging portions;

molding said segment ring with an insulating material; and

cutting the outer peripheral surface of said segment ring to remove said bridging portions, thereby to complete a commutator.

3. A method of manufacturing a commutator comprising the steps of;

preparing a straight length of metal with tapered ends;

forming said straight length of metal into a circular commutator blank, said ends being positioned adjacent and spaced in parallel with each other, thereby to form a parallel space;

forming a locating portion on said circular commutator blank;

inserting said circular commutator blank into an extrusion press;

locating said parallel space of said circular commutator blank by said locating portion in a plane in which one of a plurality of cutting edges of a mandrel of said extrusion press is placed;

extruding said circular commutator blank, thereby to elongate the metal thereof and to form a segment ring including a plurality of parallel gaps on the inside thereof and bridging portions formed across the outer ends of said gaps, said parallel space being elongated and positioned along a line of one of said bridging portions;

molding said segment ring with an insulating material; and

cutting the outer peripheral surface of said segment ring to remove said bridging portions, thereby to complete a commutator.

4. A method of manufacturing a commutator comprising the steps of:

preparing a straight length of metal with tapered ends;

forming said straight length of metal into a circular commutator blank, said ends being positioned adjacent and spaced in parallel with each other, thereby to form a parallel space;

forming a locating portion at said parallel space of said circular commutator blank;

inserting said circular commutator blank into an extrusion press;

locating said parallel space of said circular commutator blank by said locating portion in a plane in which one of a plurality of cutting edges of a mandrel of said extrusion press is placed;

extruding said circular commutator blank, thereby to elongate the metal thereof and form a segment ring including a plurality of parallel gaps on the inside thereof and bridging portions formed across the outer ends of said gaps, said parallel space being elongated and positioned along a line of one of said bridging portions;

molding said segment ring with an insulating material; and

cutting the outer peripheral surface of said segment ring to remove said bridging portions, thereby to complete a commutator.

5. A method of manufacturing a commutator comprising the steps of;

preparing a straight length of metal with two ends;

forming said straight length of metal with first tapered portions at both ends;

forming said straight length of metal with a second tapered portion at one of said two ends;

forming said straight length of metal into a circular commutator blank, said two ends being positioned adjacent each other, thereby to form a parallel space by said first tapered portions spaced in parallel with each other and to form a locating portion by said second tapered portion;

inserting said circular commutator blank into an extrusion press;

locating said parallel space of said circular commutator blank by said locating portion in a plane in which one of a plurality of cutting edges of a mandrel of said extrusion press is placed;

extruding said circular commutator blank, thereby to elongate the metal thereof and form a segment ring including a plurality of parallel gaps on the inside thereof and bridging portions formed across the outer ends of said gaps, said parallel space being elongated and positioned along a line of one of said bridging portions;

molding said segment ring with an insulating material;

cutting the outer peripheral surface of said segment ring to remove said bridging portions, thereby to complete a commutator.

6. A method of manufacturing a commutator comprising the steps of;

preparing a straight length of metal with tapered ends;

forming said straight length of metal into a circular commutator blank, said ends being positioned adjacent and spaced in parallel with each other thereby to form a parallel space;

inserting said circular commutator blank into an extrusion press;

locating said parallel space of said circular commutator blank in a plane in which one of a plurality of cutting edges of a mandrel of said extrusion press is placed;

extruding said circular commutator blank, thereby to elongate the metal thereof and form a segment ring including a plurality of parallel gaps on the inside thereof and bridging portions formed across the outer ends of said gaps, said parallel space being elongated and positioned along a line of one of said bridging portions;

molding said segment ring with an insulating material; and

cutting the outer peripheral surface of said segment ring to remove said bridging portions, thereby to complete a commutator.