US2631207A - Balanced relay armature operated switch - Google Patents

Description

' w. H. KUNTZ BALANCED RELAY ARMATURE OPERATED swncn March 10, 1953 2 SHEETS-SHEET 1 Filed March 22, 1950 o x I INVHVTOR. g 20 Z.

March 10, 1953 w. H. KUNTZ 3 BALANCED RELAY ARMATURE OPERATED SWITCH Filed March 22, 1950 2 $HEETSSHEET 2 46 if 53 21 i i v .5. +661 i 6& 4 72 26 Ilmllll I INVENTOR.

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Patented Mar. 10, 1953 BALANCED RELAY ARMATURE OPERATED SWITCH William H. Kuntz, Grand Rapids, Mich., assignor, by mesne assignments, to AMI Incorporated, a corporation of Delaware Application March 22, 1950, Serial No. 151,179

4 Claims. 1

The present invention relates to electrical relays. It is the primary aim of the invention to provide a relay of the type wherein the armature contacts close only momentarily, in which the time interval through which the contacts stay closed is controlled with split-second accuracy, so that the interval for which the contacts close is almost absolutely uniform, irrespective of Wide variations in the duration or potential of the electrical pulse employed to energize the relay winding.

When conventional relays are energized by a momentary electrical pulse, it has been found that the interval of time over which the contacts remain closed varies widely, particularly when the relays are energized by alternating current. It is believed that while various factors may contribute to this result, it is primarily due to the fact that, since the circuit throughrthe relay winding may be closed at any point in the voltage curve of the alternating current cycle, the instantaneous voltage applied to the winding may vary from zero as the current source reverses polarity, to a maximum as it reaches a peak of its voltage curve. Obviously the various potentials which may thus be imposed on the winding by random closing of the energizing circuit at various points of the voltage curve of the current supply will bring about varying characteristics of performance of the armature. For example, consider the effect of momentarily energizing a relay winding from a 115-v. A. C. supply. In such a supply, the actual voltage at any given instant reaches zero at the end and center of each cycle, and rises to a maximum of something-in the range of 160-v. at the peaks of the voltage curve. Thus, if the relay winding is designed for proper operation on the root mean square voltage of 110-120, it will function normally only if the circuit is closed during the portion of the voltage curve at which such voltage prevails, and will be insufficiently energized if the circuit is closed as the instantaneous voltage passes through zero, or over-energized if the circuit is closed when the instantaneous voltage is at its maximum. In actual tests, it has been learned that some high grade conventional relays, when energized momentarily from such an A. C. supply, will show a surprising lack of uniformity as to the time interval over which their contacts stay closed. In fact, it has been found that the time interval may vary from as little as .0001 of a second to about 1 cycles; that is, about -of a second. In many types of equipment, this erratic performance introduces serious functional difficulties, and it is accordingly the primary object of the present invention to provide a momentary closing relay which is suitable for use on alternating as well as direct current, wherein the armature contacts are held closed for a fixed interval of split second uniformity, irrespective of whether the energizing pulse to the actuating winding begins at the zero, peak, or some intermediate portion of the voltage curve.

It is a further object of the invention to provide an electrical relay wherein this result is inherent in the design and construction of the mechanical structure of th relay itself, so that it is not dependent on auxiliary governors or controls, and so that it closes for a uniform interval irrespective of whether it is actuated by its own winding or moved by some other mechanism, as by the armature of an interlocking relay. According to the present teaching, this object is accomplished by a relay in which the armature is stabilized to accomplish the uniformity of function set out above by simple mechanical means requiring no additional electrical circuits or timing devices.

A still further object of the invention resides in the provision of a stabilizing armature for a relay, wherein a pivoted armature of conventional design is provided with a stabilizing weight, supported on the opposite side of said pivot on the free end of a resilient spring, and provided with limit stops which permit relative movement of the weight and spring in one direction from their position of rest, and prevent such movement in the opposite direction. It has been learned that very precise control of the movement of the armature contacts may be obtained by this expedient.

A further object of the invention is the provision of a stabilized armature having the functional characteristics outlined above, wherein the principal mass of the stabilizing weight is in substantially the same plane and on the opposite side of the armature pivot from the principal mass of the remainder of the armature, so that the stabilizing weight not only serves to cause the armature contacts to close for a uniform split second interval of time, but also functions as an armature counterweight to prevent accidental functioning of the contacts as a result of jolts, jars or physical impacts accidentally or deliberately imposed upon the relay. This is of particular advantage in relays designed for use in the control circuits of coin-operated machines, to prevent persons from beating the machine by jolting or jarring it in such a manner as to momentarily close the contacts of a relay in the credit circuit.

Further objects of the invention will appear in the following specification, taken in connection with the drawings thereof, in which the teachings of the invention are disclosed in a preferred embodiment as applied to a relay of the interlocking armature type.

In the drawings:

Figure 1 is a front elevational view of an interlocking relay constructed in accordance with the present teachings, the armatures of the relay winding being shown in interlocked position, the relay including breaker contacts on the auxiliary armature through which the circuit of the main relay winding is completed, so that the energizing pulse is automatically interrupted after a momentary duration;

Figure 2 is a front elevational View similar to Figure 1, but with the parts in the changed position which they assume after the main winding has been energized and at the instant that the armature moves to close its contacts and close the external circuit of the device;

Figure 3 is a schematic wiring diagram or the relay, the armatures thereof being illustrated in the position the parts are shown in Figure 1;

Figure 4 is a front elevational view of the relay similar to Figures 1 and 2, but with the armatures shown in unlocked position;

Figure 5 is a plan sectional View, taken substantially on the plane of the line 5-5 of Figure 4; and

Figure 6 is an end elevational view.

The relay here disclosed is shown as including a flat mounting bracket l0 having a top flange H and a bottom flange l2, with the relay frame (generally designated as l3) mounted on the bracket by a pair of machine screws l4. These screws pass through spaced openings in the bracket l0 and are threaded into a pair of spaced ear portions lb of the relay frame (Figure 6). This frame, consisting of a stamping of magnetically permeable material such as iron or soft steel, is shaped to include a flat base It in which the iron cores I1 and [8 of the windings l9 and 23 are mounted. The winding i3 may be termed the main relay winding, and the winding 26 is the auxiliary winding thereof. The opposite ends of the base l6 are bent upwardly to form arm portions 2| and 22 which are provided with brackets 23 and 24 having ear portions 25 and 23 to support the pivots 21 and 28 of the relay armatures. The brackets 23 and 24 may be secured to the arm portions 2! and 22 in convenient manner, but as shown, they are held by the machine screws 29 and 30.

The pivot 28 supports the armature of the auxiliary winding 26. This armature, which is generally designated as 3|, comprises a magnetic slug 32 extending inwardly from the pivot 28, which is also of magnetically permeable material, so that the slug is positioned directly above the upper end or pole portion 33 of the core IS. The slug 32 is held away from the pole piece 33 by a light coil spring 34, which is attached to the lower end of a right angled tensioning bracket 35 fixed to the slug 32 by a pair of machine screws 35. This bracket also includes a downwardly bent locking portion 37, which engages a similar portion on the main armature of the unit. The auxiliary armature 3| also includes a spring contact blade 33 mounted between insulating strips 33 secured to the slug 32 by screws 40. The blade 38 has a movablecontact 4! at its free end, which is adapted to engage a fixed contact 42 carried on an insulating strip 43 secured to an ear 44 of the frame by screws 45.

The main armature of the relay, generally designated as 46, is mounted on the pivot 2? in a manner similar to but oppositely oriented from the armature 3|. The main armature MS has a magnetic slug 4'! extending from the. upper end of the arm 2| across the pole piece 45' of the winding 19 and carries an angle bracket 49 extending downwardly alongside the member 2!. This bracket supports one end of the tension spring 34, which is also secured to the bracket 35 so that both armatures are spring biased into open position by the same spring. The angle bracket 43 is secured to the slug 4'? by machine screws 53 and is provided with a downwardly extending portion 51 at its end terminating in a locking hook 52 which engages and coacts with the locking portion 31 of the armature 3|. The armature 46 also carries a spring contact blade 53 which is mounted on insulating strips 55 secured to the slug by screws. 55. This contact blade has a moving contact 56 at its free end in a position to engage a fixed contact 51 secured at the upper end of an insulating strip 58 mounted on an ear .59 of the frame by a pair of screws 66'.

The several parts of the unit are so shaped and proportioned that when in the locked position of Figure 1, the bracket 43 of the main armature 43 contacts the lower end of the supporting bracket 2| at BI and limits the action of the spring 34 so as to hold the slugs! well above the pole piece 58 and hold the contacts 5651 open. In this position, the contacts ll-42 are held closed by the locking hook portion 52 of the armature 46, which engages the locking portion 37 of the armature 3!, so that the slug 32 is held in depressed position and the spring 34 held partially extended.

In this form of the invention, the circuit through the main winding I9 is extended through the contacts 41-42,, so that whenever this winding is energized, its armature will move downwardly to the position of Figure 2, and in so doing, will release the locking armature 3| to permit it to break the contacts 4! and 42: and interrupt the current fiow through the main winding (Figure 4). The contacts 56-5l are provided to control an external circuit, while the auxiliary winding 26 is energized from a separate source.

The several parts of the relay as thus far described may be more or less conventional in design and construction, and are illustrated in the present application primarily for the purpose of showing the environment in which structural features of this invention find their greatest usefulness. It has been mentioned, however, that it is the primary purpose of the present invention to provide means whereby the contacts of the main relay armature (that is, the contacts 56 and Si of the present disclosure) are mechanically stabilized so that they close for almost precisely the same time interval on each actuation of the armature, irrespective of variable factors such as variable duration of the energizing current or varying potentials thereof. To this end, the relay armature is provided with a stabilizing weight S5, which as illustrated is in the form of a T- shaped slug (Figure 6) shown as including an enlarged head portion 63 and a downwardly depending stem Bl. The stem 67 is pierced to accommodate a pair of machine screws 58 by which the slug is secured to the depending free end 69' of a resilient spring 70, which has its opposite end ailixed to the armature by the screw 56. The spring is a thin metal strip and is biased toward the armature bracket, so that itsfree end tends to urge the end of the lowermost screw 68 into light pressure contact with the bracket 49 at the point H. The spring 10 thus forms ashiftable mounting on which the slug 65 is carried, and is biased to exert a few grams of pressure against the bracket 49 at this point, H, so that it normally holds the screw in contact therewith. Thus, the bracket acts as stop means carried by the armature to limit the inward swinging movement of the slug stem 61 toward the bracket, but the free end 69 of the spring is resilient enough so that it may flex outwardly. Thus, when the winding I9 is energized to actuate the armature and close the contacts 56 and '51, the inertia of the slug 65, which tends to continue its motion after the armature slug 4'! strikes the pole 48, will flex the spring and allow it to swing outwardly to a position such as illustrated in Figure 2.

The efi'ect of this stabilizing weight and spring is to cause the contacts 56 and 51 to stay closed for almost precisely the same interval on each successive actuation, irrespective of variations in the energizing current. That is, when the parts are in the position shown in Figure 1 and the winding I9 is energized, the entire armature tends to pivot in a clockwise direction around the pivot 21. At this time, since the screws 68 are contacting the bracket 49 at II, the parts will all move in unison. After the contacts 56-51 engage, however, and when the slug 4'! strikes the pole piece 48, the motion of the slug and angle bracket will be interrupted, but the inertia of the stabilizing weight 65 will cause it to swing outwardly as in Figure 2. In this position it imposes a flexing action on the free end 69 of the spring, and it has been found that as a result of this action, the interval before the contacts 56-5| disengage is maintained at an almost absolutely uniform value. In this respect, the stabilizing mass and spring appear to normalize the movement of the armature and to prevent improper contact timing, irrespective of whether the cause of such timing arises from weak actuation of the winding or from overactuation, which brings about objectionable rebound in conventional devices.

In the form of the invention illustrated in the drawings hereof, the T-shaped stabilizing weight 65 is positioned so that its principal mass is on the opposite side of the pivot 21 from the principal mass of the remaining parts of the armature, and is substantially in the same plane as the armature slug 41. By this expedient, the weight 65 serves not only as a contact stabilizing weight to control the timing of the closing movements of the contacts 56-5'|, but also functions as an armature counterbalance to prevent physical impacts from causing the contacts to close. This is of considerable importance in controls of instruments such as mechanical phonographs, etc., where the relays are employed in the credit circuits of the device, since it prevents persons from cheating the machine by shaking, jolting or jarring it to close the contacts of the relays in the credit circuits. In

view of this function of the weight 65, a similarly shaped counterweight 12 is mounted on the bracket 35 of the locking armature 3|, but since there is no need of accurately controlling the closing movements of the contacts associated 6 with this armature, the weight is mounted directly on the bracket rather than being provided with the yieldable supporting spring.

From the foregoing, it should be apparent that the tendencies of a conventional relay toward erratic performance as a result of variations in the actuating pulse may be overcome in a very simple, direct and, straightforward manner by the provision of a relatively simple stabilizing mechanism attached to the armature of the relay itself and requiring no external controls, regulators, or additional electrical parts. Moreover, this stabilizer may be so designed, as in the present disclosure, so that in addition to holding the contacts closed for the precise regulated interval desired, it functions a an instrumentality to prevent the contacts of the relay from closing due to accidental jolts and jars or to deliberate impacts on the relay mounting. These functions are accomplished, moreover, by a device of extreme mechanical simplicity, which is entirely automatic in its functioning and requires no additional power or separate source of energy.

The preferred embodiment of the invention has been illustrated and described in detail herein, but it is recognized that various modifications and variations thereof may be made without sacrifice of all of the advantages of this structure and without deviation from the inventive concept here disclosed. It is accordingly pointed out that the inventive thought is not limited to the precise form of the invention shown, but extends to any variation or modification thereof within the terms of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by United States Letters Patent is:

1. In an electrical relay, an electrical winding and a magnetic core having a pole portion at one end, with an external magnetic circuit comprising a magnetically permeable member having a base extending outwardly from th core at the end remote from the pole having an arm extending alongside the winding to a point adjacent the pole portion thereof; a magnetic armature for said relay mounted on a pivot adjacent said arm and extending across said pole portion, an electrical contact carried by said armature, means normally biasing said armature to an inoperative position, and a sp g havin one end affixed to the armature and the other end free, an armature counterbalancing and stabilizing weight carried on the free end of said spring on the opposite side of said pivot from said armature, and stop means carried by said armature between the weight and said arm to limit the movement of said weight relative to said armature in one direction, said spring means carrying said weight normally urging said weight into engagement with said stop means whereby movement of said armature and contact upon operation of said electrical winding occurs within a predetermined time interval and the armature is substantially unaffected by shocks.

2. In an electrical relay, an electrical winding and a magnetic core having a pole portion at one end, with an external magnetic circuit comprising a magnetically permeable member having a base extending outwardly from the core at the end remote from the pole having an arm extending alongside the winding to a point adjacent the pole portion thereof; a magnetic armature for said relay mounted on a pivot adjacent said arm and extending across s'aidpole portion, an electrical contact carried by said armature, means normally biasing said armature to an inoperative position, and a spring havin one end afiixed to the armature and the other end free, an armature counterbalancing and stabilizing weight carried on the free end of said spring on theopposite side of said pivot from said armature, said weight having its principal mass substantially in the same plane as said armature and on the opposite side of said pivot from said armature, and stop means carried by said armature between the weight and said arm to limit the movement of said weight relative to said armature in one direction, said spring means carrying said weight normally urging said weight into engagement with said stop means whereby movement of said armature and contact upon operation of said electrical winding occurs within a predetermined time interval and the armature is substantially unaffected by shocks.

3. An electrical relay armature, means for energizin and pivoting said armature about a pivot, means normally biasing said armature to an inoperative position, a spring having one end aiTXed to said armature and the other end free, an armature counterbalancing and stabilizing Weight carried on the free end of said spring on the opposite side of said pivot from said armature, and stop means carried by said armature to limit the movement of said weight relative to said armature in one direction, said spring means, which is positioned between said weight and stop means, normally urging said weight into engagement with said stop means whereby movement of said armature upon'energization occurs within a predetermined time interval and the armature is substantially unaffected by shocks.

4. An electrical relay armature, means for energizing and pivoting said armature about a piv- 0t, means normally biasing said armature to an inoperative position, a spring having one end afiixed to said armature and the other end f an armature counterbalancing and stabilizing weight carried on the free end'of said spring on the opposite side of said pivot from said armature, said weight having its principal mass substantially in the same plane as said armature and on the opposite side of said pivot from said armature, and stop means carried by said armature to limit the movement of said weight relative to said armature in one direction, said spring means, which is positioned between said weight and stop means, normally urging said weight into engagement with said stop means whereby movement of said armature upon energization occurs within a predetermined time interval and the armature is substantially unaffected by shocks.

WILLIAM H. KUNTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,014,257 Rosenqvist Jan. 9, 1912 1,151,720 Ruddick Aug. 31, 1915 1,162,571 Chubb Nov. 30, 1915 1,190,588 Rogers July 11, 1916 1,222,257 Auth Apr. 10, 1917 1,316,983 Thompson Sept. 23, 1919 1,462,860 Hunt July 24, 1923 2,155,052 Byland Apr. 18, 1939 2,180,539 Miller Nov. 21, 1939 2,195,041 Von Schlippe Mar. 26, 1940 2,265,297 Little Dec. 9, 1941 2,277,111 Johnson Mar. 24, 1942 2,362,855 Stimson Nov. 14, 1944 2,394,601 Fiehl Feb. 12, 1946 FOREIGN PATENTS Number Country Date 341,221 Great Britain Jan. 15, 1931

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