US3436701A - Unitary armature relay having constant actuating time and method - Google Patents

Description

April 1, 1969 RELAY HAVING CONSTANT ACTUATING TIME AND METHOD R. HAYDEN 3,436,701 UNITARY ARMATURE Filed April 14, 1967 23 a: S 3o 27 v 29 f H? FIG 2 0/ 28 l9 s N N 9 FIG 3 29 V 3Q lF-o lo H s 32 33 |9 2e 22 N 35' 30 T I6 x INVENTOR RODNEY HAYDEN United States Patent Claims priority, application Canada, Feb. 28, 1967, 983,946 Int. Cl. H01h 9/00, 50/18 U.S. Cl. 335-203 3 Claims ABSTRACT OF THE DISCLOSURE A relay having a unitary armature which is adapted to be connected to a direct current source. The armature is of a ferrous metal that is capable of being magnetized and includes a movable end which carries a contact and a detent spaced from and limiting movement of said end with a direct current passing through the contact, the movable end of the armature is constituted a magnetic pole and the detent an opposite pole. Thus magnetic properties are generated which, under certain conditions tend to cause the movable armature end to stick to the detent.

Background of the invention While a relay of the type with which this invention is concerned may function properly under some loads, such as one or two lamps when the load is increased, as by the addition of one or more lamps, the current through the armature will increase to such an extent as to create magnetism in the armature which will impai the operation of the movable contact by creating a tendency for it to quickly part from the detent, thu interfering with separation in the intended time. This results in destroying the sensitivity of the frequency provided by the relay.

Summary of the invention With this condition in mind, the invention has, as an object, the provision of a relay including a current carrying armature and a coil having a core with the armature and coil being related to neutralize any magnetism in the armature when a direct current flows therethrough in a prescribed direction.

Thus, with the movable arm of the armature constituted a north pole for the residual magnetism created by the current, the current is passed through the coil in the direction to constitute the end of the core adjacent to the movable arm a north pole. The magnetism of the coil is much greater than the residual magnetism in the armature which it overcomes and causes the contacts to engage and at the same time neutralizes any magnetism which may have been created in the armature.

Various other more detailed objects and advantages of the invention, such as arise in connection with carrying out the above noted ideas in a practical embodiment, will in part become apparent, and in part be hereinafter stated, as the description of the invention proceeds.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawings.

Brief description of the drawing 'FIG. 1 is a perspective of an obturato included in flasher systems and is representative of the condition with no current applied;

"FIG. 2 is a perspective similar to FIG. 1 depicting the condition which obtain when current flows through the coil in the wrong direction:

3,436,701 Patented Apr. 1, 1969 Description of the preferred embodiments Referring now to the drawing, and first more particularly to FIG. 5 a battery is shown at 10. A strip of conducting metal is indicated at 11. This strip is comparable of the strip constituting the armature of the relay of this invention. A line 12 connects the positive side of the battery 10 with the end 13 of the strip 11. Another line 14 connects the negative side of the battery 10 with the end 15 of the strip 11.

With direct current flowing from the battery 10 in the direction of the arrows appearing on lines 12 and 14 the strip 11 is magnetized and the end '13 is the south pole of the magnet and the end 15 the north pole.

Referring now to FIG. 1 an obturator is therein illustrated and identified in its entirety by the reference character 0. It comprises an armature in the form of an integral continuous ferrous strip comprising an end wall 16, a base 17, a curved or arcuate end wall 18 and a movable top piece 19. The latter extends outwardly over the top edge 21 of end Wall 16 from which it is spaced and projecting outwardly from the movable top piece 19 is a tongue 22. Carried on the underface of the latter is a contact 23. The top piece 19 is formed with an aperture 24 and passing therethrough is a narrow strip 25 which upstands from the edge 21 of front wall 16. The strip 2'5 is bent over to provide a detent 26 that is positioned over the tongue 22 in narrowly spaced, substantially parallel relation thereto. This spacing ha been exaggerated in the showings of the drawings to the end of clarifying illustration.

A core 27 upstands from the base '17 and its upper end 28 is normally spaced from the underside of the top piece 19. A coil 29 is wound about the core 27 and included in an appropriate circuit, such as that of a flasher, a will be later described.

Referring now to FIG. 2 the condition which is created when a direct current is passed through the coil 29 in the wrong direction will be described. A fixed contact 30 is shown as spaced below the movable contact 23 with which it co-operates.

With direct current passing through the armature, as through base 17, curved end wall 18, and top piece 19, the latter is magnetized and the end portion thereof, including the tongue 22 is constituted the north pole and the detent 26 the south pole. With current passing through the coil 29 in the direction of the arrows the core 27 is magnetized with the end 28 becoming the south pole. Thus top piece 19 is drawn downwardly towards the core and the tongue 22 is correspondingly moved to bring the contact 23 into engagement with the fixed contact 30. However, in achieving this engagement of the contacts the tongue 22 must be separated from the detent 26 with the separation being resisted by the residual magnetism.

As opposite poles attract when the current is interrupted any residual magnetism in the top piece 19 and tongue 22 is effective to tend to hold the detent and tongue together and retard separation. It has been found that this difficulty is not so apparent when the load of the circuit is small, say for instance a single lamp. But when the load is increased, as by adding one or more lamps to the circuit the resulting increase in current is reflected in an increase in the armature magnetism which causes the core to achieve the separation more quickly than in the cases of lesser current.

FIG. 3 depicts the correct direction of current flow and the condition created thereby. The only change over FIG. 2 is that current flows through the coil 29 in a direction opposite tothe direction of FIG. 2. This causes the end 28 of core 27 to become a north pole.

While like poles repel the magnitude of the magnetism of coil 27 and core 29 is so great as compared to any residual magnetism in the top piece 19 therelay functions in the manner intended as described above because the residual magnetism in piece 19 is overcome. At the same time any magnetism in top piece 19 is neutralized by the magnetism of core 27.

Referring now to FIG. 4 a typical flasher circuit including the relay of this invention will be described. Thus a battery 31 is grounded at 32, as to the chassis of the vehicle in which the flasher is installed. A resistor 33 is connected to the battery 31 by a line including a control switch 34. A bus line 35 is connected to the other end of the resistor at junction 36. One side of a capacitor 37 is connected to junction 36 and a line 38 extends from the other side. The coil 29 is connected between the ends of lines 35 and 38.

A line 39 extends from the line 38 to a lamp load represented at 40. The fixed contact 30 is connected to the line 39 at 41. Another line 42 extends from the battery side of the resistor 33 to the armature to which it is connected as at 43.

From the foregoing it is apparent that if the relay is to function with the uniformity of frequency required current must pass through the coil 29 in the proper direction. As a test to determine this factor the relay is first used in a circuit with a load of say one lamp. The frequency of operation for a prescribed period is noted. A second lamp is added which increases the current. If the frequency now increases it indicates that the current is While preferred specific embodiments of the invention are hereinbefore set forth it is to be clearly understood that the invention is not to be limited to the exact constructions, mechanisms and designs illustrated and described because various modifications of these details may be provded in putting the invention into practice within the purview of the appended claims.

I claim:

1. For use in a circuit providing an intermittent current of constant frequency, a unitary armature relay comprising an armature in the form of an integral strip of ferrous metal through which a direct current passes, said strip providing an end wall having an upper free edge, an extension of said wall beyond said edge and having a bent portion constituting a detent; a base integrally joined to the lower edge of said end wall; a second end wall integrally joined to said base; a movable top piece integrally joined free edge, being formed with an aperture through which said extension passes, a tongue extending from said top piece beneath said detent in operative relation thereto, a contact carried by said tongue; said direct current passing through said strip imparting megnetism thereto and op posite polarity to said tongue and detent; a core positioned between said base and top piece and having an up per end normally spaced from said top piece; and a coil disposed about said core and having a direct current passing therethrough in a direction imparting the same polarity to said core end as that which obtains in said top piece.

2. The unitary armature relay of claim 1 in which the second end wall is curved.

3. The unitary armature relay of claim 1 in which the top piece and upper core end are both north poles.

References Cited UNITED STATES PATENTS 2,890,308 6/1959 Debrey 335163 3,128,357 4/1964 Hartig 335 3,223,861 12/1965 Steiner 335250 3,295,023 12/1966 Peras 335-207 3,308,407 3/1967 Lake 335203 BERNARD A. GILHEANY, Primary Examiner.

H. BROOME, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,436,701 April 1 1969 Rodney Hayden It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 15, "of should read to Column 4, line 6, "provded' should read provided line 17, after "joined" insert to said second end wall at one end and extending over said Signed and sealed this 21st day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

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