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Dual Rate Magnet Return Spring

IP.com Disclosure Number: IPCOM000052926D
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Bryant, KM: AUTHOR [+2]

Abstract

When a magnet is energized to pull the armature 12 into engagement with yoke 14, extension spring 10 is tensioned to provide a restoring force. Under normal circumstances residual magnetism between the armature 12 and yoke 14 will cause the armature to remain sealed for a short period of time after the relaxation of the magnetic field. Then and only then, after the residual magnetism has diminished, will the force of spring 10 be sufficient to break the seal and allow armature 12 to restore. A technique for overcoming this residual magnetism and to improve the drop time is disclosed in Figs. 1 and 2.

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Dual Rate Magnet Return Spring

When a magnet is energized to pull the armature 12 into engagement with yoke 14, extension spring 10 is tensioned to provide a restoring force. Under normal circumstances residual magnetism between the armature 12 and yoke 14 will cause the armature to remain sealed for a short period of time after the relaxation of the magnetic field. Then and only then, after the residual magnetism has diminished, will the force of spring 10 be sufficient to break the seal and allow armature 12 to restore. A technique for overcoming this residual magnetism and to improve the drop time is disclosed in Figs. 1 and 2.

Fig. 1 shows a compression spring 16 which will be compressed by the sealing of armature 12 against yoke 14. As the magnetic field is relaxed spring 16 will exert a force upward breaking the seal between armature 12 and yoke 14 thereby allowing restore spring 10 to quickly drop the armature.

An alternative technique (Fig. 2) is to use a material to form a residual gap in the form of a cantilevered spring or beam. Cantilevered beam 18 may be of a nonmetallic nonmagnetic material such as rubber, or may be a spring which will act to separate the armature 12 from yoke 14, thereby allowing a rapid response to the release of armature 12 by spring 10. Spring 10 may then be a relatively low spring constant member inasmuch as it will be assisted by either compression spring 16 or beam 18 to allow a rapid drop time.

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