Laminated solenoid plunger for solenoid assembly

• US 7,414,504 B2
• Filed: 06/14/2006
• Issued: 08/19/2008
• Est. Priority Date: 06/14/2006
• Status: Expired due to Fees

• Current Assignee: Datacard Corp. (Entrust Corp.)
• Original Assignee: Datacard Corp. (Entrust Corp.)
• Inventors: Johnson, Peter E., Lundstrom, Robert W.
• Primary Examiner(s): Enad; Elvin
• Assistant Examiner(s): Musleh; Mohamad A
• Application Number:
  US11/452,534
• Publication Number:
  US 20070290779A1
• Time in Patent Office: 797 Days
• Field of Search: 335/214, 335/220, 335/224, 335/251, 335/255, 335/257, 335/259, 335/263, 335/264, 335/298
• US Class Current: 335/255
• CPC Class Codes: B41J 3/385 of plates, e.g. metal plates, plastic cards
• CPC Class Codes: B44B 5/0061 characterised by the power drive
• CPC Class Codes: H01F 2007/086 Structural details of the armature
• CPC Class Codes: H01F 7/1623 Armatures having T-form
• CPC Class Codes: H01F 7/1638 Armatures not entering the winding

Abstract

A solenoid plunger for use in solenoid driven multi-line embossing systems is constructed of magnetic steel laminations that are attached to a center block which is machined to mount a solenoid shaft and anti-rotate pins. The laminations are attached to the center block with screws and vacuum epoxy glued for a very high cycle life. The laminated steel construction dramatically reduces eddy currents, which allows the magnetic field to rise and fall much more quickly than a conventional steel plunger. It also increases the magnetic force in the solenoid. This reduction in solenoid plunger eddy currents and increase of magnetic force in the solenoid structure itself operates to increase embosser throughput. The laminated steel construction further reduces embosser solenoid heating which also contributes to improved embossing control.

Claims

1. A solenoid plunger plate, comprising:

first and second laminated stacks, each stack having a plurality of alignment cavities, each alignment cavity configured for receiving an alignment mechanism there through, wherein laminations within each stack are abutting adjacent laminations;

a center block having a plurality of alignment cavities, each alignment cavity configured to receive an alignment mechanism, the center block disposed between the first and second laminated stacks;

a clamp having a plurality of alignment cavities and configured to receive the first and second laminated stacks and the center block therein; and

a plurality of alignment mechanisms, each alignment mechanism being inserted into a respective clamp alignment cavity, a corresponding first stack alignment cavity, a corresponding second stack alignment cavity and a corresponding center block alignment cavity and configured to tighten the clamp against the first and second laminated stacks and the center block, wherein the first and second laminated stacks, center block and clamp together are aligned to provide a substantially flat face portion of the solenoid plunger plate.

2. The solenoid plunger plate according to claim 1, further comprising a solenoid shaft mounted to the substantially flat face portion of the center block in a direction perpendicular to the substantially flat face portion of the solenoid plunger plate to formulate a solenoid plunger.

3. The solenoid plunger plate according to claim 1, further comprising a plurality of anti-rotate pins mounted to the substantially flat face portion of the center block in a direction perpendicular to the substantially flat face portion of the solenoid plunger plate.

4. The solenoid plunger plate according to claim 1, wherein the first and second laminated stacks are comprised of steel.

5. The solenoid plunger plate according to claim 1, wherein the first and second laminated stacks are comprised of sintered material.

6. The solenoid plunger plate according to claim 1, wherein the first and second laminated stack laminations are welded to the adjacent laminations in at least one spot between each lamination.

7. The solenoid plunger plate according to claim 1, wherein the alignment mechanism comprises a screw.

8. The solenoid plunger plate according to claim 1, wherein the alignment mechanism comprises a nut and a bolt.

9. The solenoid plunger plate according to claim 1, further comprising vacuum applied epoxy glue that is vacuum applied to each alignment mechanism.

10. A solenoid plunger plate, comprising:

first and second laminated stacks, each stack having a plurality of alignment cavities, each alignment cavity configured for receiving an alignment mechanism there through, wherein laminations within each stack are abutting adjacent laminations;

a center block having a plurality of alignment cavities, each alignment cavity configured to receive an alignment mechanism, the center block disposed between the first and second laminated stacks;

a plurality of alignment mechanisms, each alignment mechanism being inserted into a respective first stack alignment cavity, a corresponding second stack alignment cavity and a corresponding center block alignment cavity and configured to secure the first and second laminated stacks against the center block, wherein the first and second laminated stacks and the center block together are aligned to provide a substantially flat face portion of the solenoid plunger plate; and

a round solenoid shaft mounted to the center block so that the shaft extends therefrom in a direction perpendicular to the substantially flat face portion of the solenoid plunger plate to formulate a solenoid plunger.

11. The solenoid plunger plate according to claim 10, further comprising a plurality of anti-rotate pins mounted to the center block so that the pins extend in a direction perpendicular to the substantially flat face portion of the solenoid plunger plate.

12. The solenoid plunger plate according to claim 10, wherein the first and second laminated stacks are comprised of steel.

13. The solenoid plunger plate according to claim 10, wherein the first and second laminated stacks are comprised of sintered material.

14. The solenoid plunger plate according to claim 10, wherein the laminations of the first and second laminated stacks are welded to adjacent laminations in at least one spot between each lamination.

15. The solenoid plunger plate according to claim 10, wherein the alignment mechanism comprises a screw.

16. The solenoid plunger plate according to claim 10, wherein the alignment mechanism comprises a nut and a bolt.

17. The solenoid plunger plate according to claim 10, further comprising vacuum applied epoxy glue that is vacuum applied to each alignment mechanism.

18. The solenoid plunger plate according to claim 10, wherein each lamination comprises a cold rolled grain oriented steel lamination having an electrically insulating coating encapsulating each lamination surface.