Patents Examined by Nguyen N. Tran
  • Patent number: 6040648
    Abstract: A spindle motor having a simplified construction with reduced axial and radial deflection while avoiding the half whirl phenomenon includes a motor frame, a rotating shaft supporting a rotor, a stator and stator coil, a permanent magnet opposing the stator, and a liquid dynamic pressure bearing. Magnetic centers of the permanent magnet and stator coil, in the axial direction of the rotating shaft, are substantially matched. The liquid dynamic pressure bearing comprises opposing surfaces of the rotating shaft and the housing. The rotating shaft has a disk-shaped thrust bearing portion disposed in a first portion of a cylindrical hole of the housing, and a radial bearing portion disposed in a second portion of the cylindrical hole. Lubricating oil fills a space between the cylindrical hole and the thrust bearing portion and radial bearing portion, and a presser ring is pressed and fixed into a third portion of the cylindrical hole to seal the bearing.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: March 21, 2000
    Assignee: Seiko Instruments Inc.
    Inventors: Naoki Kawawada, Hiroaki Namiki, Isamu Takehara, Tadao Iwaki, Takashi Ishida, Shinichi Hayashizaki, Hirotada Shimaguchi, Katsushige Konno
  • Patent number: 5744883
    Abstract: A switch lever for use with a centrifugal starting switch of an electric motor. The starting switch has at least one switch contact which is moveable, in response to axial movement of a centrifugal actuator, between a start position in which a starting winding of the motor is energized and a run position in which the starting winding is de-energized. The switch lever of the present invention operatively connects the switch contact with the centrifugal actuator for movement in response thereto. The switch lever has a cam follower at one end which is engageable with an annular actuator collar of the centrifugal actuator. The cam follower includes a contoured rear cam face which prevents the cam follower from becoming "stuck" behind a flat rear surface of the actuator collar during assembly or operation of the motor.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: April 28, 1998
    Assignee: Emerson Electric Co.
    Inventors: William Lewis, Thomas Ottersbach