(19)
(11) EP 0 438 321 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
05.08.1992 Bulletin 1992/32

(43) Date of publication A2:
24.07.1991 Bulletin 1991/30

(21) Application number: 91300423.0

(22) Date of filing: 18.01.1991
(51) International Patent Classification (IPC)5: H01H 3/16, H01H 21/28
(84) Designated Contracting States:
DE ES FR GB IT

(30) Priority: 19.01.1990 JP 3125/90 U
10.09.1990 JP 237239/90

(71) Applicant: OMRON CORPORATION
Kyoto 616 (JP)

(72) Inventors:
  • Maeda, Masayuki
    Nagaokakyo-city, Kyoto (JP)
  • Niwa, Takashi
    Saga, Ukyo-ku, Kyoto (JP)
  • Kitamura, Takao
    Kurayoshi-city, Tottori (JP)
  • Maeta, Kazuo
    Touhaku-gun, Tottori (JP)
  • Yamane, Norihito
    Kurayoshi-city, Tottori (JP)
  • Morisawa, Tatsuhide
    Saihaku-gun, Tottori (JP)

(74) Representative: Calderbank, Thomas Roger et al
MEWBURN ELLIS York House 23 Kingsway
London WC2B 6HP
London WC2B 6HP (GB)


(56) References cited: : 
   
       


    (54) A limit switch and a method for manufacture of a rotary shaft for the limit switch


    (57) The invention relates to a limit switch comprising a housing, a switch element contained in the housing, a rotary shaft, a journal means supporting the rotary shaft, a roller lever secured to one end of the rotary shaft for driving the shaft, a cam portion formed at the other end of the rotary shaft and a plunger and an auxiliary plunger through which the switch element is driven by the cam portion, improvements wherein the rotary shaft has a grease reservoir means axially disposed at its periphery to lubricate sliding surfaces of the rotary shaft and journal means. The invention further provides a method of manufacturing a limit switch rotary shaft which comprises die-casting a rotary shaft using a split die consisting of an upper segment and a lower segment which are configured to form a couple of axially extending plane areas to serve as grease reservoirs along their parting line and a multiplicity of minute hills and valleys for improved lubrication on the peripheral surface of the rotary shaft.






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