US Patent: 4,771,358 - Magnetic chuck controller


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US Patent: 4,771,358

Magnetic chuck controller

Patentee:

Alan R. Millner (exact or similar names) - Lexington, MA

USPTO Classifications:

361/145, 361/149, 361/190, 361/205

Tool Categories:

metalworking machines : grinders : magnetic chucks

work holding : magnetic chucks

Assignees:

Walker Magnetics Group, Inc. - Worcester, MA

Manufacturer:

Walker Magnetics Group, Inc. - Worcester, MA

Witnesses:

Unknown

Patent Dates:
Applied:	Nov. 09, 1987
Granted:	Sep. 13, 1988

Patent Pictures:

USPTO (New site tip)
Google Patents
Report data errors or omissions to steward Jeff Joslin
Vintage Machinery entry for O. S. Walker & Co.

Description:

Electromagnetic chuck that is controlled by semiconductors. The controller includes a demagnetizing sequence that briefly reverses the current to remove residual magnetism. Feedback circuitry is used to provide effective demagnetizing across a wide variety of workpiece sizes and geometries while also avoiding current spikes that can damage the semiconductors.

This patent number is listed in a 1995 Walker Magnetic Chucks catalog, for their Electromagnetic Chuck Controls, available for their MSD ("Interloc") series of electromagnetic chucks.