US3457533A - Force transfer electrical relay - Google Patents

Description

y 19691 Rmo. WHITAKER 3,457,533

FORCE TRANSFER ELECTRICAL RELAY Filed Dec. 5, 1966 FIG. I I I FIGQ 32 zg fie a, fizz-#20 m 133 ll! lfl 14 28 ll \2 /I4 FIG. 4 Alb;

United States Patent Office 3,457,533 Patented July 22, 1969 3,457,533 FORCE TRANSFER ELECTRICAL RELAY Ranald 0. Whitaker, 3145 N. Delaware, Indianapolis, Ind. 46205 Filed Dec. 5, 1966, Ser. No. 599,037 Int. Cl. H01h 3/00 U.S. Cl. 335-192 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to electrical relays of the type used in electrical appliances such as remote controls for TV receivers. More particularly it relates to the spring arrangement which returns the armature to open position.

In accordance with the invention, a leaf spring fixed to the free end of the armature touches at its tip a stop fixed to the frame. The stop is so placed that it tends to hold the armature in open position. Activation of the magnet moves the armature to close position. During closure a portion of the spring between the stop and the armature comes against a contact fixed to the frame. Flexure of the spring causes its tip to lift from the stop. That portion of the magnet pull which would have ben delivered to the stop is transferred to the contact.

The action cited above is in marked contrast to that of the conventional relay. In the conventional relay a counter spring tends to open the contact at all times. Part of the pull of the magnet is used to overcome this counter spring. There is no transfer of pull to the contact.

Since current carrying capacity of a pair of contacts is a function of the force with which the contacts are pressed together, it follows that a relay built according to the present invention can carry a greater current than a conventional relay.

Accordingly it is the object of this invention to provide a relay which for a given primary power can control a greater secondary current.

A detailed explanation of the invention will be given referring to the drawings, in which:

FIG. 1 is an elevation view of a relay constructed in accordance with the present invention.

FIG. 2 is an elevation view of a conventional relay.

FIG. 3 is a partial elevation view of a relay fabricated in accordance with a modification of the present invention.

FIG. 4 is a partial elevation view of a relay fabricated in accordance with a second modification of the present invention.

FIG. 5 is an elevation view of a relay fabricated in accordance with a second configuration of the present invention.

Referring to FIG. 1, an electromagnet 2 having a polepiece 4 is fixed to frame 6. A pin 8 in frame 6 serves as a pivot for armature 10. A leaf spring 12 is fixed at the farther end of armature 10. Fixed to spring 12 is bar 13. Endpiece 14 of electrically insulating material is fixed to frame 6. Bar 13 rests against stop 16 which caps endpiece 14. An electrical terminal 18 is fixed to endpiece 14. A contact 20 is fixed at its tip directly opposite to contact 22 fixed to bar 13. FIG. 1 shows the parts in the position they would assume before the magnet is activated. When magnet 2 is activated, armature 10 closes and comes to rest against polepiece 4. As the left end of spring 12 moves downward, contact 22 closes against contact 20. Flexure of spring 12 attending further movement of armature 10 downward lifts tip 24 from stop 16.

The above action is to be contrasted with the action of the conventional relay of FIG. 2. In this conventional relay armature 10 extends to the left. Spring 28 biases armature 10 in the counter-clockwise direction. Stop 26 fixed to endpiece 14 holds armature 10 in position. Activation of magnet 2 causes armature 10 to rotate clockwise about pin 8 until contact 22 comes to rest against contact 20 carried on terminal 18. It is apparent that a portion of the magnet pull is at all times used to overcome spring 28.

Numerous variations of the invention are possible. In the structure of FIG. 1, gravity may be relied upon to keep armature 10 in position shown during periods when the magnet is not activated. Tension spring 33 fixed t0 armature 10 at point 32 and to frame 6 at point 34 may be eliminated. It follows that the relay will not operate properly when oriented so that gravity acts to open the relay. This restriction may be removed by the structure of FIG. 3. Upper stop 30 fixed to endpiece 14 limits the upward motion of armature 10. Spring 33 may be replaced by a coil spring installed about pin 8. It may also be replaced by a leaf spring between armature 10 and frame 6 and biased to rotate armature 10 in the clockwise direction.

It is apparent that force developed on bar 13 as a result of such spring will be transferred to contact 22 when magnet 2 is activated. Consequently both magnet 2 and this spring pull on the contact when the magnet is activated.

In the variation of FIG. 4, a contact 40 is placed on endpiece 14. A second contact 42 is placed on spring 12 opposite contact 40. Closure of the relay causes separation of these contacts as spring 12 flexes after engagement of contacts 20 and 22. The resultant unit is a singlepole double-throw relay.

In another variation bar 13 is omitted and spring 12 is extended to stop 16. A small reduction in cost is realized. Performance is slightly impaired.

Another variation is indicated in FIG. 5. Spring 12 is fixed to endpiece 14. Tension spring 33 biases armature 10 toward closed position. Spring 12 acting through stop 16 holds armature 10 in open position prior to activation of magnet 2. When magnet 2 is activated, armature 10 moves toward closure. Contact 22 fixed to armature 10 closes to contact 20 on spring 12. Further movement of armature 10 causes flexure of spring 12 which in turn causes stop 16 to lift from armature 10. Spring 33 augments the pull of magnet 2 in closing contact 22 to contact 20. Consequently this structure is equally effective in achieving the object of the invention as was the structure of FIG. 1.

It is apparent that parts may be so chosen that the torque developed on armature 10 by spring 33 may be much greater than the torque developed by magnet 2 when activated. The greater the torque due to spring 33, the greater the force on stop 16 must be. Activation of magnet 2 serves to switch this force from stop 16 to contact 20. The present invention serves as a force switch. The force it switches may be several times the force developed by the magnet itself.

Additional contacts may be added to provide any of the multiple variations of conventional relays.

The following are claimed:

1. An electrically operated relay comprising:

a frame;

a magnet fixed to said frame;

an armature connected to said frame and adapted to be moved relative to said frame when said magnet is activated;

means including a first spring fixed to the free end of said armature;

a stop fixed to said frame and spaced from said magnet, said stop being positioned to intercept said means and hold said armature in open position when said magnet is in deenergized state; and

at least one electrical contact pair, the first contact of each pair being positioned on said means between said stop and said magnet, the second contact of each pair being connected to said frame between said stop and said magnet and in alignment with each first contact;

said contact pairs closing on partial closure of said armature; and

moved relative to said frame when said magnet is activated;

means including a first spring spaced from said magnet and fixed to said frame;

at least one electrical contact pair, the first contact of each pair being positioned on said means and the second contact of each pair on said armature;

a stop fixed to said means between said first contact pair and said magnet and positioned to intercept said armature and hold said armature in open position when said magnet is in a deenergized state;

said contact pairs closing on partial closure of said armature; and

said first spring being adapted to flex and disengage said stop from said armature upon further closing of said armature.

4. An electrically operated relay as in claim 3 and having a second spring connected between said armature sald first Sprmg bemg adapted to flex and ms and said frame, biasing said armature toward closed posiengage said stop upon further closing of said armatrue. 20 tion 2. An electrically operated relay as in claim 1 and References Clted having a second spring connected between said armature UNITED STATES PATENTS and said frame, biasing said armature toward closed posi- 1,531,347 4/ 1922 Rhodes 335--276 XR tion. 25 2,795,669 6/1957 Campbell 335-124 3. An electrically operated relay comprising: ,259,812 7/ 1966 ONeil 335266 a frame;

BERNARD A. GILHEANY, Primary Examiner D. M. MORGAN, Assistant Examiner a magnet fixed to said frame; an armature connected to said frame and adapted to be

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