US2425562A - Relay with adjustable armature mounting - Google Patents

Description

Aug. 12, F X. REES RELAY WITH ADJUSTABLE ARMATURE MOUNTING Filed March 29 1944 ||V I 41| ii llllhl Illnm IIIIII FIG. I I Hlllllll FIG.. 10.

Patented Aug. 12, 1947 RELAY WITH ADJUSTABLE ARMATURE MOUNTING Frank X. Rees, Chili, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application March 29, 1944, Serial No. 528,556

(Cl. F75- 345) 4 Claims. l

This invention relates in general to relays oi the electromagnet type, and has more particular reference to an improved form of code following relay, adapted more particularly for use in connection with railway operation.

The relay of the present invention is an iniprovement in the form of relay disclosed in the Field application, Ser No. 351,003, iiled August 3, 1940, now Patent No. 2,360,664, dated October 17, 1944, for Relay.

In the operation of relays of the type to which the present invention relates, there is a tendency upon movable contacts striking against iixed contacts, to vibrate and bounce for a short period of time, during which time the control circuits are not effectively made, and during which time -there is excessive arcing at the contacts and burning of the points. This is particularly the case if the contacts carry heavy currents and the relay is energized at a low level in the interest of economy in operating costs. As a result, this faulty type of operation materially decreases the useful life of the relay contacts and reduces the efficiency and economy of operation and maintenance.

With the above and other considerations in mind, it is proposed in accordance with this invention, to provide a relay in whi-ch these defects are very largely obviated.

One of the objects of the present invention is to produce a relay wherein the movable contacts do not bounce or vibrate on the iix contacts, whereby to vastly improve the operating characteristics of relays of this type.

Another object of the present invention is to produce an improved, yet simple, form of adjusting means for the air gap between the armature and certain of its cooperating pole pieces.

Further objects, purposes and characteristic features of this invention will appear as the description progresses, reference being made to the accompanying drawings showing, solely by Way of example, and in no manner whatsoever in a limiting sense, one form `which the invention can assume. In the drawings- Fig. l is a fragmentary sectional view, with parts shown in elevation, of a relay constructed in accordance with the present invention.

Fig. 2 is a fragmentary view of a detail of construction.

Fig. 3 is a fragmentary view, with parts shown in section, of air gap adjusting means.

Figs. 4-9 are fragmentary views showing various operative positions of the relay contacts.

Fig. is a View showing operative charac,-

teristics of a relay in accordance with this invention.

Fig. 11 is a view showing oscillograins of current conditions in a conventional relay and in a relay in accordance with the present invention.

Referring now to the drawings, a fragmentary portion of a relay, in accordance with this invention, is shown in Fig. l. Only such parts of the relay will be described as are necessary for a complete understanding of this invention. The velay is shown as of the polar neutral type, but aan, of course, be of any other type, and is biased by spring means to make up its back contacts, whereby it responds only to current of a particular polarity, to move its movable contact iingers so as to make up its front points. This operation is the same as set forth in the Field application, above referred to. A y

The relay includes a top plate TP, on which are supported the electromagnetic operating means I2 and I3, and the permanent magnet operating means III. The relay includes an armature I5, cooperating with the electromagnet pole pieces I6 and II, and the permanent inagnet pole pieces or shoes, I8 and I9. The armature rocks on a bearing comprising a hardened bearing block 20, extending across the permanent magnet pole shoes and received in slots in the shoes, as shown at 2| and 22 (Fig. 3). Between the block 20 and the armature, and received in a V-shaped slot in the armature, is a cylindrical pivot rod 24.

The armature is shown in its spring biased position, that is, rocked clockwise so as to bear against the electromagnet pole shoe II by adjustable spring bias means `53 and 54. The armature is supported by a spring supporting means 25, suitably carried by, and adjustable on, a support arm 26, carried by the top plate.

Connected to, and carried by, the armature is an operating arm 21, having one end fastened to the armature, as by bolts 28 and 29. The operating arm 2l terminates, at its outer end, in a tong-like jaw having an upper portion 30, and a lower portion BI, which jaw receives, and holds in compressed, pretension fashion, spaced contact ngers 32 and 33.

These contact fingers 32 and 33 constitute rnovable ngers which are operated by the jaw portions 30 and 3|, by means ofthe armature of the relay, and cooperate with Xed contact lingers 35 and 36. The contact ngers 35 and 3E carry contact points 31 and 33, and are backed up by `adjusting screws 39 and 40 carried by stiff, absolutely rigid arms 42 and 43, whereby to make the back contacts absolutely lixed and unyelding when the movable contacts strike them.

The movable contact fingers 32 and 33 are made of relatively thin, light springy material, are relatively short in length, and are connected at one end, as at 45, to a short light spring member 46, which, together with arms 42 and 43, are carried by a contact block 41, connected as by screws 48, to a bracket 49, supported from the top plate as by bolts B.

As shown in the drawings, the movable contact fingers 32 and 33, carry contact points 5l and 52, for cooperating, respectively, with the fixed contact points 31 and 38.

The armature is biased to its deenergized, or non-operative polarity position, by the means 53 and 54. Thus, the relay, as shown in Fig. l, can be considered to be making up its back points, in which condition the movable contact point 5I, is in contact with the fixed contact point 31.

Means are provided, in accordance with this invention, to readily adjust the polar air gap between the armature and the permanent magnet pole shoes. The permanent magnets, as I4, are each received in a socket member, 56, which constitutes the permanent magnet pole shoes I8, and is bolted to the top plate, as by means 51, as clearly shown in Fig. 1-

The permanent magnet, as I4, is received in a socket 58 in this receiving member, and is held against becoming loose by a spring locking means 59, as shown in detail in Fig. 2. This spring locking means 59 comprises a flat central portion with upturned ends 60 and 6l, drilled as at 82 and 63, to receive the ends of the permanent magnets. When the parts are assembled the upsprung ends 60 and 6I are sprung, as shown in Fig. 1, between each permanent magnet and its receiving socket, and thus the spring operates to hold the two permanent magnets in xed position and free from all vibration and play.

Extending from the lower face of each receiving socket, as the socket 58, is a drilled hole, which receives a threaded adjusting screw 64, which bears at its lower end against one end of the pivot bearing bar 20. This screw and the corresponding one in the other socket, can be moved in` wardly or outwardly to position the bearing bar 2U a greater or lesser distance from the lower face of the permanent magnet pole shoes, whereby to vary the gap between the armature and the permanent magnet pole shoes. The adjusting screws, as 64, are held in adjusted position by set screws, as 66.

From the above description it can be seen that very rigid and quite immovable back and front xed contact fingers and contact points are provided for cooperation with movable contact fingers which are relatively short and light. Hence, in making Contact with either of the iixed contact points, there is but little energy in the movable lingers to tend to produce vibration, or bouncing, with respect to the Iixed contact points. Furthermore, the armature, with its operating arm 21 for operating the movable contact lingers, does not carry the movable contact iingers, and hence the mass of the armature is not involved in tending to produce any bouncing, or vibration, upon making up of front, or back, points.

In Figs. 4-9 are shown various operative positions of the contacts of this invention, and it may be helpful to consider them somewhat in detail.

In Fig. 4, the movable contact fingers are shown separate, and entirely free, from the, operating arm 21. It can be seen that they are formed to have a natural bias to position them in a widely spaced relation, of an extent considerably greater than the spacing between the jaw parts 33 and 3|. Thus, when these movable fingers are pressed towards each other so as to be received in the operating jaw parts, as shown in Fig. 5, there is a very considerable amount of trapped tension or pretension. This condition is shown in Fig. 5, and the operating arm 21 is shown in its position half-way between full deenergized, and energized, positions.

In Fig. 6 is shown the position of the contacts, and associated parts, when the operating arm 21 has moved the movable contact fingers so as to pass just very slightly beyond the point wherc the movable point 5| touches the fixed point 3'! and thus to transfer the trapped tension in the movable linger 32, to contact pressure between the two Contact points in contact with each other.

In Fig. 7 the parts are shown in the positions they assume when the back Contact is fully made up. It can be seen that the operating arm 21 has moved somewhat further than as shown in Fig. 6, and that the upward jaw part 33, which in Fig. 6 is still in contact with its movable contact finger 32, is now spaced therefrom (Fig. 7), whereby to, in eirect, largely separate the mass of the armature from contributing to any tendency for the contact points to vibrate or bounce. Also, further contact pressure has been developed.

In Fig. 8, the parts are shown in the positions assumed in moving from fully making up its back point, as shown in Fig. 7, to having just made up its front point. This corresponds to the showing in Fig. 6.

In Fig. 9 the parts are shown in the positions assumed when the front point is fully made up, and full contact pressure is realized; and this corresponds to the showing in Fig. 7, where the back point is fully made up and full contact pressure is realized.

In Fig. 10 is a diagrammatic showing of the above described operative characteristics of the contacts of this invention. Represented along the horizontal axis AT, is armature travel, while represented along the vertical axis CP, is contact pressure. As seen by the curves in this figure, the contact pressure is at a maximum at the armature position b, which is the position of the armature when the back contact is fully made up, as for instance, in the condition shown in Fig. 7. As the contact lingers move toward making up the front contact, and just before they break contact with the back contact, the contact pressure is as shown at 68, and is the pressure produced by the trapped tension in contact finger 32, and as can be seen, is about one-half of what the pressure is when the points are fully made up.

Upon a very slight further movement toward the front contact making position, the pressure on the back point falls to Zero, as represented at B8. The condition when neither xed contact point is made up, and the movable fingers are intermediate the front and back fixed contact points, is represented in Fig. 10 at the zero portion 'l0 of the curve. The contact pressure curve 1l, for the front points, is identical with the one just described. This portion 1l has a portion made up by the trapped tension, and a further portion made up by further armature travel.

Referring now to Fig. 11, there are here shown two oscillograms, the lower of which represents contact current conditions in an improved relay in accordance with the present invention, while the upper represents the corresponding characteristics in a conventional type of relay. Such relay is one in which the contact ngers are carried by the armature, and in which there is no pretension or trapped tension in the contact fingers.

Referring iirst to the upper oscillogram, the tracing '12, is produced by an alternating current of 60 cycles and furnishes a suitable scale for reading elapsed time. The other tracing in this oscillogram represents the amount of current flowing through a movable contact point, and hence is a measure, under fixed conditions of voltage, etc., of the resistance between the movable contact point and its fixed point. The portions 13 of the curve indicates that the contacts are fully open and no current flows through the movable contact point. In other words, there is a sufficient gap, as when the contact points are open to prevent all current flow. The portion 14 of the curve represents current flow at its highest level, and thus represents the condition with the contacts fully made up, and with full pressure. In the conventional relay, on making up a movable point with a fixed point, there is considerable vibration and bouncing for a considerable period of time. During this time the resistance across the points varies widely from the minimum, when the contact pressure is fully established, to a resistance equal substantially to that when the contacts are fully open.

In the oscillogram, the portion 'l5 of the curve, comprising a series of vertical lines arranged closely side by side, and connecting the lower and upper lines 13 and le, indicates that, for a period of time, the contact point resistance varies back and forth from a maximum to a minimum. After this, as represented b-y the portion 'i6 of the curve, the resistance uctuates considerably, but within narrower limits than earlier, and changes, over a period of two or three cycles of the 60 cycle current, from a minimum resistance, to a very substantially increased resistance.

As a result, it can be seen from this oscillogram that, upon making up a movable contact with a iiXed contact (in the conventional relay), the circuits thus controlled, are not properly closed for a considerable period of time at the beginning of the circuit closed period, and that during this time a very considerable amount of sparking and .burning and even mechanical wear, of the contact points, necessarily takes place.

Referring now to the lower oscillogram, the 60 cycle timing tracing is represented at 11, the maximum level of current flow is represented at '58, and the period of Zero current now is represented at 19. It can be seen from this oscillogram that no current flows when the contacts are open and that, upon the movable contact touching the iixed contact, the circuit is at once closed with the minimum resistance, so that, for the entire period of contact closed condition, current flows in the circuit at a uniform, and the highest, level. As a result, substantially all arcing and burning of contacts, and mechanical wear of the same, is obviated, and the relay is much longer lived, and more dependable. Also, the circuits controlled, as, particularly, in the case of a relay following a relatively fast code, are controlled much more accurately and dependably.

Thus, in applicants relay, unlike the conventional relay, there is no tendency, during mid i the order of about .013".

stroke and at the time contact is made, to vibrate or whip, because of the fingers being held, with trapped tension, in the operator.

Also, the anvil effect, i. e., the tendency for the finger to bounce 01T of the fixed contact so generally present in conventional constructions, is largely eliminated in applicants relay, due to the high degree of trapped tension in comparison with the small mass of the moving parts involved.

While the proportions, and relative amounts of movement, of the various parts oithis relay, can be varied within any reasonable limits, without departing from the spirit of the present invention, it should be understood that the construction described above, and the relative lightness of the iingers, and amounts of trapped tension, and movements, are to a large extent an essential part of the present invention. While not restricting the invention to any particular set of values, one set which has been found in actual practice, to work outI to distinct advantage, may well be given. It is a relay constructed in accordance with this particular set of values, that produced the oscillograph readings shown in the lower oscillogram of Fig. l1.

In this relay, the full contact finger pressure is 55 grams, while the trapped tension is 30 grams. The travel from full contact pressure to trapped tension pressure, that is, on Fig. l0, the horizontally measured distance from the point b to the point 63, is .025, and the movement, measured horizontally from the point 08, to the point @9, is something less than .001. rEhe movement over the period where Zero pressure exists, is in The spacing between the movable contact fingers 32 and 33, when they are open, as in Fig. 4, is about .110 while, when they are compressed so as to be received in operator 2l, but still out of contact with either front or back fixed contacts, as in Fig. 5, the spacing etween the fingers is about .070.

As indicated above, the relay of this invention is particularly adapted to be used to follow coded current, often times of a high rate, and to be energized from a track circuitl Thus, under varying Weather conditions, the level of energy applied to the relay, and depended upon to produce proper relay operation, will vary widely from time to time. Furthermore, the utmost economy in energy consumption is sought.

Under conditions such as outlined above, the usual and conventional relay is often rather unsatisfactory, and is particularly so when the level of energization falls to its minimum. Under such conditions and requirements, however, relays constructed in accordance with this invention, perform in a most satisfactory manner, and thus solve the very difficult problem of providing a relay of satisfactory operative characteristics, even when employed so as to effect the maximum of economy in energy consumption, and under conditions of widely varying degrees of energization,

The novel bearing structure illustrated more particularly in Figs. l and 3 is claimed herein whereas the novel non-bounce contact structure is claimed in divisional application, Ser. No. 646.632, iled February 9, 1946.

The above rather specific description of one form which the present invention can assume, is given solely by way of example, and is not intended, in any manner whatsoever, in a limiting sense. It is to be understood that various modifications, adaptations and alterations may, from time to time, be applied to meet the requirements of practice, Iwithout in any manner departing 7 from the spirit or scope of the invention, except as may be limited by the appended claims.

What I claim is:

l. In relays, in combination, a top plate, a pole piece extending through and fastened to the plate, a faced pole shoe on one end of the pole piece, a core receiving socket in the other end of the pole piece, a receiving slot in the face of the shoe, a pivot bearing bar slidable in the slot, a threaded opening connecting the bottom of the socket to the base of the slot, and an adjusting screw in the opening and bearing against the bar.

2. In relays, in combination, a top plate, two spaced pole pieces each extending through and fastened to the plate, a faced pole shoe on one end of each pole piece, a core receiving socket in the other end of each pole piece, aligned receiving slots in the faces of the shoes, an elongated pivot bearing bar extending across the pole shoes and slidably received in the slot, a threaded opening connecting the bottom of each socket to the base of its slot, an adjusting screw in each Opening and bearing against the bar, and a set screw for fixing the adjusted position of each adjusting screw.

3. In relays, in combination, a top plate, two spaced pole pieces extending through and fastened to the plate, a pole shoe on one end of each piece, a core receiving socket in the other end of each piece, aligned receiving slots in the faces of the slices, an elongated pivot bearing bar slidable in the slots, a threaded opening connecting the bottom of each socket with the base of its slot, an adjusting screw in each opening and bearing against the bar, a core received in each socket and having a shoulder for limiting its projection into the socket, means for holding the cores in their sockets, and spring bias means for holding the cores tight and including an elongated plate like member of spring material extending from one core to the other and having its ends positioned between the core shoulders and the pole shoes, each said end having an opening to allow the core to pass therethrough and being bent at an angle to the plane of the body of the plate like member.

4. In relays, in combination, a top plate, two spaced pole pieces each extending through and fastened to the plate, a faced pole shoe on one end of each pole piece, a core receiving socket in the other end of each pole piece, aligned receiving slots in the faces of the shoes, an elongated pivot bearing bar extending across the pole shoes and slidably received in the slot, a threaded opening connecting the bottom of each socket to the base of its slot, and an adjusting screw in each opening and bearing against the bar.

FRANK X. REES.

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

UNITED STATES PATENTS

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