US3418609A - Square obturator - Google Patents

Description

Dec. 24, 1968 R. HAYDEN SQUARE OBTURATOR Filed April 17, 1967 INVENTOR RODNEY HAYDEN United States Patent 3,418,609 SQUARE OBTURATOR Rodney Hayden, Stoney Creek, Ontario, Canada, assignor, by mesne assignments, to United-Carr Incorporated, Boston, Mass., a corporation of Delaware Filed Apr. 17, 1967, Ser. No. 631,527 Claims priority, application Canada, Feb. 28, 1967,

83,944 6 Claims. (Cl. 335-203) ABSTRACT OF THE DISCLOSURE A square obturator primarily for use in an electric relay formed from a continuous strip of low carbon steel having a projecting tongue which carries a contact, and so constructed that it can be easily adjusted accurately and then set to hold this adjustment after the manufacture of the relay.

Background of the invention An obturator is included in an electric relay to control the gap across a pair of contacts. Thus a part of the obturator may constitute the armature of the relay. It has been the practice for manufacturers of these devices to provide various set screw arrangements for controlling the gap across the contacts. Such arrangements have been recognized as being undesirable because of the manufacturing costs involved.

It has been proposed to provide an obturator of the type noted including a fixed base and a movable top piece spaced from the base and joined thereto by an arcuate back that is designed and constructed to maintain the contacts in a desired spaced relation. However, considerable difficulty has been experienced in imparting the required physical properties to the arcuate back piece and particularly in accurately achieving the necessary curvature thereof.

Summary of the invention With these conditions in mind the present invention has in view, as its foremost objective, the provision of an obturator of the character noted which is essentially of rectangular shape. More in detail the invention provides an obturator comprising a front vertical wall, a flat base integrally joined to the front wall by a bend, a substantially straight rear wall integrally joined to the base by a bend, and a fiat top wall integrally joined to the upper edge of the rear wall and extending over the upper edge of the front wall from which it is spaced at an appropriate distance. This top wall carries a forwardly projecting tongue which in turn carries one of the contacts aforesaid.

The top wall is movable because of the flexibility of the bends at the upper and lower edges of the rear wall and, due to the elastic nature of the material from which the obturator is produced, will always exhibit a tendency to return to a normal position to properly correlate the contact on the projecting tongue with respect to a complemental contact mounted on the same panel which carries the obturator.

The top wall of the obturator constitutes the armature of the relay and is moved under the influence of the coil thereof. One important object of the invention is to provide highly simplified means for limiting movement of the armature. Downward movement is limited by the upper edge of the front wall and upward movement by a detent in the form of a flange on a tab that extends upwardly from the front wall through an aperture formed in the top wall.

It is evident that the bends at the edges of the rear 3,418,609 Patented Dec. 24, 1968 wall determine the normal position of the top wall and are susceptible of production by conventional manufacturing processes to accurately position the top wall with respect to the base.

It may be deemed desirable to confine the flexing of the bends to a single bend at either edge of the rear wall to achieve more accurate positioning of the top wall. This may be accomplished by striking one or more kerf-like deformations in either bend whereby a rigid relation between the rear wall and the other element at the bend is established.

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 drawing.

Brief description 0 the drawing FIG. 1 is a perspective of an electric relay including a rectangular obturator designed in accordance with the precepts of this invention;

FIG. 2 is a perspective of a modified form of obturator per se; and

FIG. 3 is a perspective of still another modification.

Description of the preferred embodiment Referring now to the drawing, wherein like reference characters denote corresponding parts and first more particularly to FIG. 1 an electric relay is therein identified in its entirety by the reference character R. It includes a panel 10 which ordinarily is of insulating material.

Formed in the panel 10 is a slot 11 and passing therethrough is a strip conductor 12 which is bent over the upper face of the panel 10 as indicated at 13 with the bent portion 13 being anchored to the panel 10 as depicted at 14. Upstanding from the portion 13 is a leg 15 and secured to the upper end thereof is a carrier 16 provided on its upper face with a contact 17.

An obturator is referred to in its entirety by the reference character 0. It is made of a continuous strip of spring metal of a low carbon ferrous material of high hardness. A good example of such a material is low carbon steel, especially 1010 tin plate rolled to one quarter hard width and thickness and having a Rockwell hardness of about 52.

The obturator 0 comprises a front wall 18 to the lower edge of which is integrally joined a base 19. Upstanding from the rear edge of the base 19 is a rear wall 20 which is integrally connected to the base 19 by a bend 21. A top wall 22 is integrally joined to the upper edge of the rear wall 20 by a bend 23. This top wall 22 extends over the top edge of the front wall 18 from which it is spaced a distance that is accurately predetermined for the particular relay into which it is to be installed.

The top wall 22 has a front edge 24 and formed in the top wall 22 and spaced from this front edge 24 is an aperture 25. Forwardly of the recess 25 is a tongue 26 which carries a contact 27 on its underface. Extending upwardly from the upper edge of the front wall 18 with which it is integrally formed, and through the aperture 25 is a tab 28 the upper end portion of which is turned forwardly to form a detent in the form of flange 29.

The coil of the relay is identified at 31 and is shown a being positioned within the obturator on the base 19 with its core 30 being spaced from the top wall 22 which constitutes the armature of the relay.

When the coil 31 is energized the armature 22 is pulled downwardly causing the contact 27 to engage the contact 17. Such engagement may be accompanied by a slight flexing of the tongue 26 but any undue bending is inhibited 3 by engagement of the top wall 22 with the upper edge of the front wall 18.

When the coil 31 is de-ener-gized the elastic qualities of the metal from which the obturator is formed, and particularly at the bends 21 and 23 will cause the armature 22 to move upwardly into its normal open position in which the contacts 17 and 27 are spaced. Such upward movement is limited by the detent 29.

Should it be desired to confine the flexing action to the bend 23 and establish a substantially rigid relation between the base 19 and rear wall 20 resort may be had to the modification illustrated in FIG. 2. In this embodiment the bend 21 is shown as being deformed to provide kerf-like formations 32 which are struck from the metal of the bend and adjacent wall portions. These deformations materially impair the flexible property of the bend 21 and establish a rigid relation between base 19 and wall 20.

Likewise if it is desired to confine the flexing to the bend 21 and establish a rigid relation between the rear wall 20 and top wall 22 the construction depicted in FIG. 3 may be employed. In this form of the invention kerf-like deformations 33 are struck from the bend 23.

While a preferred specific embodiment of the invention is hereinbefore set forth it is to be clearly understood that the invention is not to be limited to the exact constructions, mechanisms and devices illustrated and described because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

I claim:

1. For use in an electric relay including a panel of insulating material a fixed contact mounted on the panel and a coil, a substantially rectangularly shaped obturator mounted on said panel and receiving said coil, said obturator being fashioned from a continuous strip of low carbon steel and comprising: a front wall having an from said front wall by a bend; a top wall constituting an armature for said coil and integrally joined to the upper edge of said rear wall by a bend, said top wall extending over said coil and the upper edge of said front wall in spaced relation with respect thereto; a tongue carried by said top wall and extending forwardly thereof; a contact on the underface of said tongue and in spaced relation to said first mentioned contact with which it is adapted to engage; said top wall being formed with an aperture adjacent to the front edge thereof; a tab on said front wall passing through said aperture; and a detent carried by said tab and adapted for engagement by said tongue to limit upward movement thereof, said bends being adapted to flex when said coil is energized to move said armature and bring said contacts into engagement and return the armature to its normal condition when the coil is de-energized under the influence of the elastic property of the steel from which said obturator is made.

2. The obturator of claim 1 in which the tongue is integral with the top wall and the tab is integral with the front wall.

3. The obturator of claim 1 in which the detent takes the form of a flange bent from and integral with the tab.

4. The electric relay of claim 1 together with a metallic plate that is interposed between said base and the upper face of said panel.

5. The obturator of claim 1 in which one of said bends is deformed to provide a kerf-like deformation which imparts rigidity to the bend.

6. The obturator of claim 1 in which one of said bends is deformed to provide spaced kerf-like deformations which rigidify the bend.

References Cited UNITED STATES PATENTS 3,308,407 3/1967 Lake 335-203 3,340,487 9/1967 Gruner 335-203 BERNARD A. GILHEANY, Primary Examiner.

H. BROOME, Assistant Examiner.

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