(19)
(11) EP 0 019 472 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
07.01.1981 Bulletin 1981/01

(43) Date of publication A2:
26.11.1980 Bulletin 1980/24

(21) Application number: 80301610

(22) Date of filing: 16.05.1980
(84) Designated Contracting States:
AT BE CH DE FR IT LI LU NL SE

(30) Priority: 18.05.1979 GB 7917477

(71) Applicant: FRANKLIN & FREEMAN (LONDON) LIMITED
 ()

(72) Inventors:
  • Newman, William
     ()
  • Peall, Alfred John
     ()

   


(54) Method and apparatus for making commutator shells, commutator shells made thereby, and commutators and rotating electric machines incorporating such shells


(57) Shells for commutators are made by performing a number of forming operations on stock metal strip before the strip is cut into lengths and rolled into a cylinder. A roller (14) forms parallel transverse grooves (18) and ribs (19) in one side of the strip. Punches (26) cut slots (27) in alignment with the grooves (18) to form fingers along one edge of the strip. Knives (32) skive underthe ribs (19) to form anchors (41). Then the strip is cropped into lengths by a punch (43), bent into a cylinder by a two-stage press and forced through a tapered sizing die (61). All operations are performed in automatic sequence on a multi-stage slide press machine.






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