US3573689A - Nonsticking obturator for direct current relays - Google Patents

Abstract

This invention relates to a nonsticking obturator for direct current relays.

Description

United States Patent Inventor Rodney Hayden Wentworth, Ontario, Canada Appl. No. 822,530 Filed May 7, 1969 Patented Apr. 6, 1971 Assignee United-Carr Incorporated Boston, Mass.

NONSTICKING OBTURATOR FOR DIRECT CURRENT RELAYS 1 Claim, 5 Drawing Figs.

U.S. C1 335/196, 335/187 Int. Cl 110111 1/26 Field ofSearch 335/196,

185,187,133, 200; ZOO/166 (B8) [56] References Cited UNITED STATES PATENTS 1,799,651 4/1931 Siegmund 200/166(B8) 2,837,616 6/1958 Jaidinger..... 335/133 3,119,911 1/1964 Cherry..... 335/185 3,158,712 11/1964 Fligue 335/196 FOREIGN PATENTS 535,565 11/1955 Italy 335/200 1,104,895 6/1955 France 200/166(B8) 1,553,062 12/1968 France 200/166(B8) Primary Examiner-Harold Broome Att0rneysPhilip E. Parker, Gordon Needleman, James R.

OConnor, John Todd and Hall and Houghton ABSTRACT: This invention relates to a nonsticking obturator for direct current relays.

Patented April 6, 1971 FIG. PRIOR ART PRIOR ART INVENTOR RODNEY HAYDEN fiMAMW F lG.5

ATTORNEY NONSTICKING OBTURATOR FOR DIRECT CURRENT RELAYS SUMMARY OF THE INVENTION This invention relates to a nonsticking obturator for direct current relays.

It is the main object of the present invention to communicate electrical current to relay contacts of an obturator-type relay to generate magnetic fields at right angles rather than in parallel at the region of the contacts.

It is a further object of the invention to provide for the conduction of electricity in obturator-type relay components associated with the'electrical contacts thereof whereby the electrical fields generated in the region of the contacts are mutually exclusive. I

With the foregoing and other objects in view the invention generally concerns an obturator class of direct current relay having contact members carried by magnetic field generator current conducting magnetizable contact portions and characterized by: structure supporting said portions each relative the other in crosswise positions of minimum interference of magnetic fields generated by currents conducted thereby.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged sectional elevation of an obturator structure of the prior art in the region of the relay contacts indicating the directions'of electrical current upon contact of same;

FIG. 2 is a section on line 2-2 of FIG. 1 and illustrates the generation of magnetic fields by the currents in the prior art structure of FIG. 1, which fields tend to hold the contacts in engagement;

FIG. 3 is the plan view of a pair of contacts and contact arms in an arrangement according to the invention illustrating current directions and generation of magnetic fields in mutually exclusive array;

FIG. 4 is an underside perspective of the contact array of FIG. 3 illustrating a particular form and arrangement of relay contacts especially adapted to accomplish the objects of the invention; and

FIG. 5 is a side elevation of a relay embodying an obturator and contact arrangement of the invention.

DESCRIPTION OF THE EMBODIMENTS In the drawings obturator contact portions 10, 11 of the prior art are shown in FIGS. 1 and 2 having contact members l2, l3 thereon in closed, energized and engaged position with electrical current flowing therethrough in opposite directions of arrows x and y respectively. As shown in FIG. 2 the electrical current directions set up magnetic fields having magnetic flux directions R andT, which being opposite cause such fields to be attractive. Thus even if portions 10, 11 are nonmagnetic, the fields generated will cause the contact members l2, 13 to be held into firm engagement while current is being conducted therethrough. Where, however, the portions 10, 11 are made of a magnetizable material as is desired in the class of obturator with which this invention is concerned, then such portions become magnetized pennanently due to the setting up and collapsing of the magnetic fields R and T progressively during the making and breaking of contacts l2, 13 serving an electrical circuit (not shown). Thus if such obturator is used in a relay form as a buzzer the initial frequency or note will gradually lower in pitch until the contacts finally appear to stick. Such condition is due to permanent magnetism in the portions 10, 11 and is not due to characteristics of contact members l2, 13.

The problem of the prior art described with reference to FIGS. 1 and 2 may be overcome by resorting to the invention disclosed in FIGS. 3, 4, and 5.

In FIG. 3 portions 10a, 11a are shown in plan view wherein one portion is oriented at with respect to the other. More precisely, the contact portions of the obturator are located to conduct electrical current in nonaligned directions .x", y preferably at a maximum angle A of relative orientation of The invention also contemplates a special form of contact member as shown in FIG. 4 wherein semicylindrical or half round contact bars 12b, 13b are mounted crosswise; i.e. at 90 to one another to present their curved 14, 15 surfaces to one another for point contact in the line of action indicated by chain line 16. Such half round contact members with their curved surfaces opposing in crosswise configuration of relative orientation are simple to fabricate and mount on the portions 10b and 11b and engage by a minimum area of contact.

In the assembly shown in FIG. 5 obturator 17 of springlike magnetizable material is clamped by its bottom arm 18 to insulate base l9 by iron core member 20 energizing coil 21 to provide a gap 22 with the free arm 23 thereof presenting a contact portion 24 mounting contact member 25 adapted to engage crosswise disposed contact member 26 on the other contact portion 27, being a stationary flange of rigid standard 28 extending upwardly from base flange 29 fixed to base 19. The stationary flange comprising the other contact portion 27 is disposed at right angles in its current carrying function to the direction of electrical current flow in portion 24 and arm 23 of obturator 17.

It will be apparent that if obturator portions 10 and 11 of FIG. I carried current in the same direction that the contact members would in due course be difficult to bring to closure or engagement because the fields generated would then be in opposing relationship. In the invention the current directions in the two portions are transverse each with respect to the other whereby the respective magnetic fields do not interfere either in an opposing or attracting sense.

Iclaim:

l. A direct current electrical relay comprising an obturator formed of a continuous length of conductive material having a free arcuate portion extending through substantially of are between a free arm portion extending tangentially therefrom and forming a part thereof, and an integral base portion, an electromagnetic coil, the coil assembled under and spaced from the free arm portion, an electrical contact on the free end of the arm portion, and a second electrical contact including a contactportion and support means spaced from and beneath the free end of the arm portion, the contact portion extending transversely across the direction of the free arm portion and the direction of the current in the free arm portion being in transversely relationship to the direction of the current in the contact portion and each contact having an elongated semicylindrical configuration and the contacts being in the same geometric relationship as the free end portion is to the contact portion. I

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UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,573,689 Dated April 6, 1.971

Inventor (5) Rodney Hayden It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Abstract: delete "This invention relates to a nonsti obturator for direct current relays.": insert This is a: obturator having elongated contacts housing axes that are 1' right angle relation to each other. This arrangement will cause the contacts to generate magnetic fields at right ang to each other.

Column 1, line 7, insert An obturator of the class with which this application is concerned is formed of a continuous strip of ferrous material in such manner as to provide in the region of the contact structure of the relax; two parallel spaced apart metal portions one of which is a movable armature portion and another of which is a stationary contact portion. The substantially parallel spa apart armature and contact portions upon communication of electrical current through the contacts causes electrical current to flow in opposite parallel spaced apart direction thereby generating an electrical field causing the contacts be held in the closed position. In result, the relay may operate in somewhat irregular fashion. If components of th obturator in the region near the contacts are formed of fer material an additional condition of permanent magnetism may arise which increases through continued use of the relay. over a period of time a permanent magnetic field may be set causing the contacts to stick and ultimately to remain clos Signed and sealed this 21 th day of August 1971.

(SEAL) Attest:

EDWARD M.FL'ETCHER, JR. Attesting Officer WILLIAM E. SCHUYLER, JR. Commissioner of Patents

Claims (1)

1. A direct current electrical relay comprising an obturator formed of a continuous length of conductive material having a free arcuate portion extending through substantially 180* of arc between a free arm portion extending tangentially therefrom and forming a part thereof, and an integral base portion, an electromagnetic coil, the coil assembled under and spaced from the free arm portion, an electrical contact on the free end of the arm portion, and a second electrical contact including a contact portion and support means spaced from and beneath the free end of the arm portion, the contact portion extending transversely across the direction of the free arm portion and the direction of the current in the free arm portion being in transversely relationship to the direction of the current in the contact portion and each contact having an elongated semicylindrical configuration and the contacts being in the same geometric relationship as the free end portion is to the contact portion.

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