3789285 is referenced by 50 patents and cites 3 patents.

The position control system using magnetic force, in which at least one pole of an electromagnet is opposed to a magnetic substance of a controlled object through an air gap therebetween so that a magnetic circuit including the magnetic substance, the air gap and the electromagnet is provided. The width of the air gap is preset to a value more than a predetermined width when the control current is zero. The controlled object is supported by at least one spring so as to be movable along a direction in which the magnetic force functions between the electromagnet and the magnetic substance. The control current of the electromagnet is controlled for adjusting the magnetic force and also a width of the air gap so as to obtain a desired position of the controlled object along the above mentioned direction. The magnetic flux density of the magnetic circuit substantially saturates at a condition where the air gap reaches a predetermined distance, while an elastic force of the spring is balanced with the magnetic force within the elastic region of the spring at the above-mentioned condition to avoid mutual collision between the controlled object and the electromagnet. The above mentioned principle can be modified for performing two or three dimensional control and rotation control for the controlled object.

Title
Position control system using magnetic force
Application Number
05/238,051
Publication Number
3789285
Application Date
March 27, 1972
Publication Date
January 29, 1974
Inventor
Nishizawa Junichi
Agent
Lobato Emmanuel J
Burns Robert E
Assignee
Handotai Kenkyu
IPC
G05b 11/00
G05D 03/18
G05D 03/14
G05D 03/20
G05B 19/39
G05B 19/19
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