ELECTRICAL RELAY WITH MAGNETIC ARMATURE RETENTION MEANS

• US 3,656,073 A
• Filed: 09/25/1970
• Issued: 04/11/1972
• Est. Priority Date: 09/25/1970
• Status: Expired due to Term

• Current Assignee: Arthur Eastman Wood, Ralph Edward Marvin, Ralston Everett Bates
• Original Assignee: Arthur Eastman Wood, Ralph Edward Marvin, Ralston Everett Bates
• Inventors: Wood, Arthur Eastman, Marvin, Ralph Edward, Bates, Ralston Everett
• Primary Examiner(s): Broome, Harold
• Application Number:
  US05/075,541
• Time in Patent Office: 564 Days
• Field of Search: 335/170,179,124,203,79,229,253
• US Class Current: 335/179
• CPC Class Codes: H01H 50/42 Auxiliary magnetic circuits, e.g. for maintaining armature in, or returning armature to, position of rest, for damping or accelerating movement

Abstract

A miniature electric relay is disclosed which includes a header member made of magnetic material. A small permanent magnet is mounted on the header member immediately under the armature such that when the armature is in its de-energized position, one end thereof contacts the permanent magnet and thus completes a low reluctance magnetic circuit having no air gaps therein. When the coil of the relay is energized, the weak strength of the permanent magnet is easily overcome by the magnetic field established by the electric coil and the armature is rotated to cause contact actuation in the usual manner. Once the end of the armature is removed from the permanent magnet and an appreciable air gap exists, the permanent magnet is of sufficiently small strength to cause no appreciable forces on the armature, and thus the presence of the permanent magnet does not require an appreciable stronger coil to overcome its effect. A conventional return spring is provided to return the armature to its deenergized position once the coil is de-energized.

Claims

1. An electrical header assembly, a magnet actuation assembly and a magnetic armature retention assembly;

2. said electrical header assembly comprising;

a. a support header member constructed of magnetic material and having a plurality of contact pins extending therethrough b. a stationary electrical contact connected to one of said contact pins;

c. a movable electrical contact having its first end connected to another one of said contact pins and having its other end positioned adjacent to said stationary contact and normally not contacting said stationary contact;

3. said magnetic actuation assembly comprising;

a. a magnetic frame including a pole piece and at least two legs;

b. a magnetic core having a first and second end, said first end being attached to said frame and said second end being spaced from said pole piece;

c. a coil, said coil being mounted around said core;

d. an armature having a first and second end;

e. means for mounting said armature for rotation about an axis of rotation adjacent to said second end of said core;

said armature being rotatable between a first position in which said first end of said armature is in contact with said pole piece of said frame and a second position in which said first end is spaced from said pole piece, thereby providing a first magnetic circuit comprising said core, said pole piece and said first end of said armature in which magnetic flux is established when said coil is energized;

4. said magnetic circuit assembly being mounted to said electrical header assembly by attaching said legs of said frame to said support header Member so that said movable electrical contact is in the path of rotation of said second end of said armature such that when said armature is in its first position, said second end of said armature moves said movable electrical contact into contact with said stationary contact;

5. said magnetic armature retention assembly comprising a permanent magnet mounted on said support header member beneath said first end of said armature such that said first end of said armature contacts said permanent magnet when said armature is in its second position, thereby providing a second magnetic circuit comprising said permanent magnet, said first end of said armature, said core, said legs of said magnetic frame and said support header member in which magnetic flux is established by said permanent magnet; and

6. biasing means for urging said armature into its second position when said coil is de-energized.

2. The electrical relay of claim 1 in which the polarity of said permanent magnet and said coil are selected such that the flux established in said first end of said armature by said coil is of opposite polarity to the flux established in said first end of said armature by said permanent magnet.

3. said magnetic actuation assembly comprising:

a. a magnetic frame including a pole piece and at least two legs;

b. a magnetic core having a first and second end, said first end being attached to said frame and said second end being spaced from said pole piece;

c. a coil, said coil being mounted around said core;

d. an armature having a first and second end;

e. means for mounting said armature for rotation about an axis of rotation adjacent to said second end of said core;

said armature being rotatable between a first position in which said first end of said armature is in contact with said pole piece of said frame and a second position in which said first end is spaced from said pole piece, thereby providing a first magnetic circuit comprising said core, said pole piece and said first end of said armature in which magnetic flux is established when said coil is energized;

4. The electrical relay of claim 3 which further includes slits in said first end of said armature to facilitate adjusting said armature relative to said pole piece when said first end contacts said permanent magnet whenever said armature is in its second position.

5. said magnetic armature retention assembly comprising a permanent magnet mounted on said support header member beneath said first end of said armature such that said first end of said armature contacts said permanent magnet when said armature is in its second position, thereby providing a second magnetic circuit comprising said permanent magnet, said first end of said armature, said core, said legs of said magnetic frame and said support header member in which magnetic flux is established by said permanent magnet;

and

6. The electrical relay of claim 5 in which said biasing means for urging said armature into its second position comprises a return spring member having one end attached to said support header member and having its other end contacting said second end of said armature.