Browse Prior Art Database

Multistroke Solenoid

IP.com Disclosure Number: IPCOM000080962D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Ecker, ME: AUTHOR

Abstract

Shown is a solenoid which employs a segmented plunger capable of independent and variable-linear displacement of the segments within a common electromagnetic field.

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Multistroke Solenoid

Shown is a solenoid which employs a segmented plunger capable of independent and variable-linear displacement of the segments within a common electromagnetic field.

Fig. 1A illustrates the cross section of a typical tubular solenoid with plunger omitted. Fig. 1B shows an exploded view of a dual-stroke plunger assembly. The plunger segments 1 and 2 are separated by a nonmagnetic material 3 having a slot 4, so as to permit a key (also nonmagnetic and part of item 2) to pass through and engage the slot 5 in segment 1. The slot and key length differential determines the relative displacement of one segment with respect to the other. The relative position of the key with respect to the slot controls delay or lost motion. The coupling of the return spring, not shown, to the appropriate segment will determine segment activity sequence.

A key requirement to the proper and full differential travel between adjacent segments 1 and 2 is adequate flux path isolation. Differential displacement is not possible without the appropriate undercut 6 located in the pole face region of the plunger. The undercuts effectively increase the magnetic reluctance between the segment ends at the pole face. This undercut precludes the shorting of the magnetic flux path of a segment in transit to one fully transferred and having a minimum gap condition.

With the energization of the solenoid field coil, the segments become magnetically polarized and result in repulsive magne...