US2298573A - Electrical contact control device - Google Patents

Description

Oct. 13, 1942. R. .1. LITTLE ELECTRICAL CONTACT CONTROL DEVICE Filed June 21, 1940 Flehl.

1 III INVENTOR RJ, Lil'He,

M12 @Jm HIS ATTORNEY the invention, with Patented Oct. 13, 1942 2,298,573 ELECTRICAL CONTACT CONTROL DEVICE Robert J. Little, Gates, N. Y., Railway Signal Company,

assignor to General Rochester, N. Y.

Application June 21, 1940, Serial No. 341,701

4 Claims.

This invention relates, in general, to contact control devices, and has more particular reference to a quick acting or snap action contact controlling means or particular value for use in connection with railway operation.

In opening and closing electric circuits, and particularly direct current circuits, it is desirable to make and break the circuits rapidly in order to minimize as much as possible the resulting wear and burning of contacts due to the formation of arcs.

With the above and other objects in view, it is proposed, in accordance with this invention, to provide a quick acting means for making and breaking circuits, the quick acting means employing permanent magnets for producing a snap action eilect, whereby to avoid undue friction and wear oi. parts as occurs in connection with spring and elastic means ordinarily employed in this connection.

More specifically, it is proposed to open and close circuit contacts by driving an operating member carrying a magnet which cooperates with another magnet carried by an operated member, with the magnet so arranged as to exert a strong bias on the members involved.

Further objects, purposes and characteristic features will appear as the description progresses, reference being made to the accompanying drawing, showing, solely by way of example, and in no'manner whatsoever in a limiting sense, several forms which the invention can assume. In the drawing;

Fig. 1 is a schematic view of one form of the invention, shown in one its operated positions. Fig. 2 is a schematic view of the same tom 01 invention as that shown in Fig. 1, but with the parts in a different operated position.

Fig. 3 is a schematic view oi a second form oi the parts shown in one operated position.

Fig. 4 is a schematic view of the same form oi."

invention as shown in Fig. 3. but with the parts shown in a different operated position.

Fig. 5 is a schematic view of a third form of the invention.

Fig. 6 is a schematic view of the fourth form 01' the invention.

Referring now to the drawing, and first to Figs. 1 and 2, there is here shown a contact controlling device involving a top plate or support TP, to which are connected movable contact fingers l and 2, carrying contact points 3 and l, for cooperating with fixed contact fingers 6 and t, and l and 8, respectively,

fingers respectively have contact joints 8 and I0, and II and H, as shown in the drawing. The contact fingers can be connected to the top plate in any usual or desired manner, one suitable form being shown in the drawing whereby each contact finger, such as 5, is clamped to the top plate by a through bolt II and nut H, with an angle bracket I! on the underside of the top plate for holding thebolt head I6 against accidental turning. Wire connections can conveniently be made to the upper end of the bolt I3,

The contacts, if desired, instead of merely being pressed against each other, by the magnetic repulsion, can be 01' the spring slip type, wherein a blade is held between two spring members so as to require considerable force to withdraw the blade.

The lower ends or the movable contact fingers l and 2 are connected in any suitable manner, as at It, to a carrier, or operated member, C, whereby to move with the carrier. This carrier is made of any suitable insulating material.

For actuating the carrier, the armature, or operating member, A, is employed, which, as shown in the drawing, is pivoted at I! to a bracket B, connected in any suitable manner to the top plate. The armature A has a slot I8 therein, for receiving an eccentric is, rotating on a center 20 wherebyto shift the armature from one side to the other 01' a pivot i1, to assume the extreme positions shown. respectively, in Figs. 1 and 2. This eccentric I! can be driven in any desired manner, as for example, by a constant speed motor such as disclosed in application Ser. No. 198,928, filed March 30, 1938 in the name of O. S. Field which application became Patent No. 2,206,667 on July 2. 1940.

Carried by the lower end oi armature A is an armature magnet AM, which, in the present form, is shown in the shape of a horseshoe with its poles N and S extending downwardly. This magnet is of the permanent type and is preterably very strong for its size and can be made 01 These fixed contact some suitable alloy such as Alnico. This material has a very high retentivity and retains its magnetism to a strong degree so as to require a very high coercive force to destroy the magnetism.

Supported by the carrier C, is a carrier magnet CM, of a shape like magnet AM, and facing with its pole shoes towardsthe pole shoes 01 the armature masnetAM. This carrier magnet CM is preferably made of the same material, Alnico,

as the armature magnet and has its poles so arranged as to have like poles opposed to the poles doing produces noiri ctio n or, rubbing gf part as usually occurs in snap actionswitches, v {j of the armature magnet, when the armature A is in an intermediate operated position.

It can be seen, with the armature and carrier magnets opposed as described above, that when the armature A is swung from the position shown in Fig. 1, toward the position shown in Fig. 2, to ultimately reach the position indicated in Fig. 1 by the dotted N pole 2|, the-like poles repel each other, and so continue to until these like poles are directly opposed to each other, whereupon added movement of the armature causes the repulsion to operate in the reverse direction, on the carrier magnet, and quickly move the carrier C to its right hand position as shown in Fig. 2 whereby to make up fixed contacts 6 and 8, and break the contacts 5 and I which are made in Fig. 1.

In Fig. 2, in dotted lines, is shown the extreme right-hand position of the south pole S, identified as 22, whereby it can be seen, upon armature A being moved to the right, that the contact pressure between contacts 4 and I2, for example, is increased as the armature approaches the position where its magnet is over the carrier magnet. Upon the two magnets becoming directly opposed, the parts are not biased to either extreme position but upon the slightest further the contacts and the structure be so arranged that the extreme position, as limited by the structure, is reached before this opposite pole opposition position is reached.

'tacts" with avery'i uick snap action and insop,

Ref erring, now to. Figs showing or fajinodified involved wherein the ,annatur erated as "the ebb, vention, and conta contactsff as descr bed this form'bf irive'nti o permanent 'magnets'so that ir e ntary tion is magnet cooperates in the operatiom; .:Eor..-ex-, c i i ;13, aedii sa r e t ee spectively y; the'afr'r'nature andrarrier have." as "adjacent andopposed,-rand.-

their north pol me exer EllC ieOLL-the' perfated ,positions oi the; .carrierq.

ight to t,-

action to 'th rv position? carrier fm'oves, a1

magnets" increases in accordance with well known prin i l s ma net ra io sand-repulse With the cooperation of two poles on each mag .oi Figs 1' r d.;2, itwca-nb e;

,des'cribedabov e, ,as the armature .h w i in-.F e

th wba pm ene. he slightest further; movement the carrier; C is moved-with a3snap*.i

r'se position, to makeup; them this -1Il 1o volve positioning-fine era1,-.;ior,m s;:ofainventionsham g by way of example, and is not inten i1 beineacoveredzby th present Referring'now to Fig. 5 of the drawing there is here shown a slightly modified form of the invention, wherein the carrier C and armature A carried by arms 36 and 31 and pivoted as at H together with the permanent magnets 25 and 26, cooperate in substantially the same manner as described above. The carrier has contacts 21 and 2B, which cooperate with fixed contacts 29 and 30, when moved to the extreme positions. The armature A in this form of invention, is illustrated as being operated from one side to the other by an armature member 31 operating against adjustable stops 32 and 33 and actuated by electromagnetic means such, for example, as described in the patent to O. S. Field, 1,969,065, granted August 7, 1934. This structure referred to is employed to advantage in flashing signals at highway crossings on railways and the present snap action means disclosed can be used to advantage in such connections.

Referring to Fig. 6, there is here shown a further form of the invention wherein magnets 34 and 35 are carried, respectively, by the armature A and carrier C the magnets being of the horseshoe type and positioned at right angles to the plans of the members which carry them instead of in the same plan, as in the case with the forms of Figs. 1, 2 and 5. In this form, the like poles repel eacf. other in the same manner as in the forms previously described, but the structure functions as does the form of Figs. 3 and 4, in that the repulsion of the two magnets continues regardless of the distance the carrier lthough, of course, it diminishes with .as yvell understood by those versed in gpi fartf'it is seen that in this form both poles magnet! effective in producing repulsion ply ne i. eac :inag'n'et, as in the lindi':

bove disclosur asevera the s idefii fidctoibfiillfltffStfltl the contact a angements'riillustrated merely by;, wa y,;-of, example; *andxi 'vari front and-back 'contac tsof zwhatsoevereiii Ta limi tihg sn modifications and alterations as m sirable gfrgmiiztimegx e associated with the operated member, means for moving the operator from one to the other of two extreme positions, a U-shaped magnet carried by the operated member, a U-shaped magnet carried by the operator and positioned to cause its poles to move in close opposition to, but out of contact with, the like poles of the carriermagnet when the-operator is intermediate its extreme positions, whereby to repel the operated member toward one or the other of the two extreme positions when the operator is in the other, or the one, extreme position, the said U-shaped magnets having their poles all in the plane of movement of the said operator.

2. In a contact operating means, an operator, a movable operated member, contacts operatively associated with the operated member, means for moving the operator from one to the other of two extreme positions, a U-shaped magnet carried by the operated member, a U-shaped magnet carried by the operator and positioned to cause its poles to move in close opposition to, but out of contact with, the like poles of the operated member carried magnet when the operator is intermediate its extreme position, whereby to repel the operated member toward one, or the other, of the two extreme positions, with a snap action, when the operator is moved beyond its intermediate position toward the other, or the one, extreme position, and to bias the operated member to the extreme position by both magnetic attraction and repulsion, the said U-shaped magnets having their poles all in the plane of movement of the said operator.

3. In a contact operating means, an operator, a movable operated member, contacts operatively associated with the operated member, means for moving the operator from one to the other of two extreme positions. a U-shaped magnet carried by the operated member, a U-shaped magnet carried by the operator and positioned to cause its poles to move in close opposition to, but out of contact with, the like poles of the operated member carried magnet when the operator is intermediate its extreme positions, whereby to repel the operated member with a snap action toward one, or the other, of the two extreme positions, when the operator is, respectively, moved beyond its intermediate position toward said other, or said one, extreme position, the operator, when moving to either extreme position, thus moving these said poles of its magnet beyond opposition to said like poles of the operated member carried magnet, and means to restrain the operator from moi'ing the poles of its magnet into opposition with opposite poles of the operated member carried magnet.

4. In a contact operating means, an operator, a movable operated member, a substantially frictionless pivot for the operated member comprising an elongated flexible strip fixed to the operated member at one end, and at its other end fixed to a stationary support, contacts oper atively associated with the operated member, means for moving the operator from one to the other of two extreme positions, a U-shaped magnet carried by the operated member, a U-shaped magnet carried by the operator and positioned to cause its poles to move in close opposition to, but out of contact with, the like poles of the operated member magnet when the operator is intermediate its extreme positions, whereby to repel the operated member toward one or the other of the two extreme positions, when the operator is in the other, or the one, extreme position, the said U--shaped magnets having their poles all in the plane of movement of the said operator.

ROBERT J. LITTLE.

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