Title:
Electromagnet
United States Patent 2098926


Abstract:
This invention relates to electromagnetic apparatus and is more particularly directed to an electromagnet or circuit breaker having means for controlling the flow of electrical energy. The invention embraces the provision of means to compensate for temperature changes affecting the electromagnetic...



Inventors:
Schneider, William G.
Application Number:
US70949134A
Publication Date:
11/09/1937
Filing Date:
02/02/1934
Assignee:
ELECTRIC AUTO LITE CO
Primary Class:
Other Classes:
335/273, 335/276
International Classes:
H01H50/60
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Description:

This invention relates to electromagnetic apparatus and is more particularly directed to an electromagnet or circuit breaker having means for controlling the flow of electrical energy. The invention embraces the provision of means to compensate for temperature changes affecting the electromagnetic device.

The invention contemplates means to position a member with respect to forces tending to move said member, said means including at least two parallel forces, one of which is substantially constant, the other variable, the combined action of which varies the effectiveness of the forces tending to move said member.

An object of the invention resides in the provision of a bimetallic hinge for the armature arrangement.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which: Figure 1 is an isometric view of a circuit breaker which incorporates the invention; Figure 2 is a side view of the device shown in Figure 1; Figure 3 is a side view of the armature of the device shown in Figure 1; Figure 4 is a bottom view of the elements shown in Figure 3; Figure 5 is an isometric view of the hinge element forming part of the invention.

Though I have shown a form of the invention as incorporated for use in a circuit breaker for controlling the current of automotive vehicle generators it is to be understood that I contemplate the use of this invention wherever it may be found to have utility.

Referring more particularly to Figures 1 and 2 of the drawing, the electromagnet or circuit breaker of the invention is provided with a base plate or member 10 suitably secured to a bracket or support 12 by means such as rivets 14. Insulating material preferably in the form of a sheet 16 is positioned between the plate 10 and a yoke member 18 which in turn embraces the regulator winding or coil 20, wound upon a core 21. Removably secured to one leg 22 of the yoke 18 is an armature or movable contact carrying member 24 shown in detail in Figures 3 and 4.

At one end of the armature 24 is positioned a contact element 26 adapted to intermittently engage a stationary or fixed contact element 28 carried by a bracket 30 the legs 32 of which are riveted or otherwise secured to the plate 10. The legs 32 may be bent as at 33 to vary the position of the contact element 28 with respect to the armature 24 and movable contact 26.

The armature 24 is provided at one end with an extension 34 recessed as at 36 for engagement with one end of a coil spring 38. The other end of the spring 38 is secured to a hooked end portion 39 of a support or bracket 40 to resiliently hold the armature away from the core 21 and thus, in the form illustrated, separate the contacts 26 and 28, it being understood that spring 38 may also be utilized to close the contacts if desired. The bracket 40 serves to adjustably support the armature 24 upon yoke 18 through the medium of a hinge element 42. Hinge 42 may be of the form shown in Figure 5, and is preferably formed of a metal having resilient characteristics, thus providing a flexible connection between the fixed support 40 and the armature 24. The hinge 42 is provided with a plurality of extensions 44 having openings 46 therein to receive securing means such as rivets 48, serving to secure the hinge to bracket 40. Openings 50 substantially parallel to openings 46 are also provided in the hinge 42 to secure the latter to the armature 24 by means such as rivets 52. By the arrangement shown the armature is positioned with respect to the coil 20, core 21 and bracket 30 so that the contacts 26 and 28 are intermittently engageable upon flexure of the hinge element 42 when the coil 20 is energized. As a means to adjust the bracket 40 with respect to the leg 22 of yoke 18, the bracket is provided with a slotted opening 41 which accommodates the shank of a screw 43 threadedly engaging the leg 22. Thus the bracket 40 is movable within the limits of the slot 41, and as the bracket 40 carries the hinge 42 the latter is adjustable with respect to the core 21 and may be maintained in tight engagement with the leg 22. The other leg 23 of yoke 18 supports a positioning or stop member 54 having armature engaging portions 56. The member 54 is projected through an enlarged portion 58 of an opening 60 in the armature 24 and bent to engage the armature at the portions adjacent the opening 60. By this arrangement, separation of the contact points 26 and 28 is limited, and may be adjusted as desired by changing the position of the extensions 56 of stop member 54. In devices of this character, temperature changes affect the action of the electromagnet materially due to the fact that such changes affect the resistance of the coil and thus the voltage required to energize the coil to attract the armature varies. As it is desirable that the armature be attracted when a given voltage is applied to the terminals, the hinge member 42 of suitable bimetal or thermometal has been provided to automatically compensate for such temperature changes. The bimetal hinge serves to compensate for both atmospheric and winding temperatures by flexing in response to either, to vary the force required to move the armature toward the coil, due to the fact that the hinge 62 will, upon temperature change tend to overcome or increase the effective action of spring 38. Thus temperature changes which have heretofore been detrimental to effective operation of such devices are compensated for by utilizing a thermo-responsive force in parallel with the spring 38 to modify its effectiveness.

In operation, the parts being adjusted to normal atmospheric temperature, the armature is held in predetermined position with respect to the coil, and, in the form shown, in engagement with the stop member d , in response to the substantially constant force or tension of spring 30.

When a given voltage is applied to the terminals the armature is attracted toward the coil and the relative position of contacts 20 and 28 varied.

However, should the temperature of the device rise above normal from an increase of either atmospheric or winding temperature, the hinge 42 compensates for such increase in temperature by flexure in response to such temperature which decreases the force required to close the contacts, by decreasing the effective action of spring 38, or should the temperature of the device go below normal from a decrease of the atmospheric or winding temperature, the hinge a% compensates for such decrease by fiexure in response thereto, by increasing the effective action of spring 30. In certain instances it may be desired that the re46 verse effect take place, namely that the hinge increase the effective action of the spring upon decreased temperature and vice versa, and this may be accomplished by a reversal of the elements or the use of a hinge having different thermo-responsive characteristics.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrated merely, the invention comprehending all variations thereof.

What I claim is: 1. In a device of the character disclosed, the combination of a magnetic core; an energizing coil thereon; a magnetic member having portions extending across one end of said core and along opposite sides thereof; a movable armature coacting with said core and substantially bridging the side portions of said magnetic member; a 56 bracket having a slot therein and a lateral end projecting portion; a thermo-responsive member secured at one end to said bracket and at the other end to said armature acting as a hinge for connecting said bracket to said armature; a coil spring secured at one end to said armature and at its other end to the lateral projecting portion of said bracket; and means on one side portion of said magnetic member cooperating with the slot in said bracket for adjustably securing said bracket to one of the side portions of sgid _magnetic member and thereby adjustably positioning the armature with respect to said core, the thermo-responsive hinge being arranged to move the armature with respect to said core upon variations of temperature to compensate for changes in the electrical resistance of the coil.

2. In a device of the character disclosed, the combination of an electro-magnet having an energizing coil; an armature for said electro-magnet; a bracket; spring means located between one end of said armature and one end of said bracket; a thermo-responsive means acting as a hinge located between said armature and the other end of said bracket to vary the effect of said spring means on said armature upon increasing tenperature.

3. In a device of the character disclosed, a base; an electro-magnet including a U-shaped yoke carried by said base; a movable armature for said electro-magnet; means for supporting said armature including a bi-metallic element; a bracket, said bi-metallic element being carried by said bracket; spring means connecting said armature and said bracket, said bracket having a slot formed therein; and means including a screw passing through said slot and cooperating with said yoke member for adjusting the position of the armature bimetallic element, spring means and bracket with respect to the electro-magnet.

4. In a device of the character disclosed the combination of an electro-magnet; a movable armature; a support for said armature; a contact on said armature; an opening in said armature; a relatively stationary contact cooperating with the armature contact and mounted for adjustment relative thereto; means carried by the electromagnet extending through the opening in said armature for adjusting the separation between said armature and said electro-magnet; spring means located between said armature and said support, said resilient means tending to separate said contacts; and a thermo-responsive hinge connecting said armature to said support tending to move said armature with respect to said electro-magnet upon variations in temperature. 5. In an electric relay the combination of an electro-magnet; a bracket; an armature; a thermo-responsive hinge connecting one end of said armature to said bracket; a spring having one end connected to said bracket and the other end to said armature; and means coacting with said bracket for adjustably positioning said armature coacting spring and bracket with respect to said electro-magnet.

6. In a device of the character disclosed, the combination of a magnetic core; an energizing coil thereon; a magnetic member having portions extending across one end of said core and along opposite sides thereof; a movable armature adjacent to the other end of said core and substantially bridging the side portions of said magnetic 44member, said armature provided with an opening; a bracket having a slot therein and a lateral end projecting portion; a thermo-responsive member secured at one end to said bracket and at the other end to said armature acting as a hinge for connecting said bracket to said armature; a coil spring secured at one end to said armature and at its other end to the lateral projecting portion of said bracket; means cooperating with -the slot in said bracket for adjustably securing said bracket to one of the side portions of said magnetic member for changing the parts carSried by said bracket including the armature with respect to said core, the thermo-responsive means being arranged to move the armature with respect to said core upon variations of temperature to compensate for changes in the electrical resistance of the coil; and means fixed to the other side portion of said magnetizable member having a portion projecting through said armature opening providing an adjustable stop for limiting the air gap of said armature away from said core caused by said spring.

7. In an electric relay the combination of an electro-magnet; a bracket; an armature; a thermo-responsive hinge connecting one end of said armature to said bracket; means for adjustably positioning said armature elements connected thereto and bracket with respect to said electromagnet including a slot formed on said bracket and a member passing therethrough and carried by said electro-magnet; and a coil spring having one end connected to said bracket and the other end to a portion of said armature for opposing movement of said armature toward said electro-magnet when the latter is locked in adjusted position.

WILLIAM 0. SCHNEIDER.