Mpc Products Corporation

David J Treadwell

Richard K Carlson

Gary A Sparks

Jerry D Hielkman

A solenoid has a multistage telescoping plunger which together produce a single stroke. Each plunger stage has a separate air gap individually associated therewith. As the first air gap closes responsive to movement of a first telescoping plunger stage, a portion of the stator becomes magnetically saturated; however, magnetic material has moved with the first plunger stage in order to bridge the saturated position which switches the flux path to a second air gap via a second of the telescoping plunger stages. An advantage is that the solenoid has a long stroke with a high pulling force on both the initial and the final ends of a continuous stroke formed by the separate movements of the first and second plunger stages.

Solenoid having multistage plunger

A detent assembly and control lever assembly in which the tactile resistance to movement at the detent, and in the overall movement of the control arm, are concurrently increased or decreased. The apparatus, in one embodiment, includes a control lever arm assembly, a variable resistance detent assembly, and a control lever friction assembly whose movement is linked to that of the detent assembly.

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Crystal Lake, IL, United States of America

David J Treadwell