US1790271A

US1790271A - Magnet and relay

Info

Publication number: US1790271A
Application number: US364727A
Authority: US
Inventors: Haroutiun K Kouyoumjian
Original assignee: Ward Leonard Electric Co
Current assignee: Ward Leonard Electric Co
Priority date: 1929-05-21
Filing date: 1929-05-21
Publication date: 1931-01-27
Anticipated expiration: 1948-01-27

Description

Jan. 27, 1931. H...K. KOUYOUMJIAN 1,790,271

MAGNET AND RELAY Filed May 21. 1929 T T M T5 =12.

MW Wiz ATTO EY Patented Jan. 27, 1931 UNITED STATES PATENT OFFICE HAROUTIUN K. KOUYOUMJ'IAN, F PROVIDENCE, RHODE ISLAND, ASSIGNOR TO WAREZ? LEONARD ELECTRIC COMPANY, A CORPORATION OF NEW YORK MAGNET AND RELAY Application filed May 21,

This invention relates to magnets and restantially constant magnetic influence on the movable part of the magnet, regardless of commercial variations in the supply voltage, or such undesirable changes in voltage as may be due to the character of the apparatus. The invention is also adapted to, control the magnetic influence upon the movable part of the magnet, if desired, in such a manner that instead of maintaining the mag netic influence substantially constant, the same may be caused to strengthen upon decrease in supply Voltage, or otherivise'serve to fulfill any required conditions in control ofthe eflective flux of the magnet upon variations in the supply of current thereto.

There are many cases in the various uses and applications ofmagnets and relays Where difliculties arise which result in undesired, or unexpected, action of the magnet, or relay, due to changes which cannot easily be controlled. For example, if a magnet is supposedto act only upon absence of exciting current, or interruption of the exciting current, it will often be found that the relay has acted when not intended, due to increased drop in the line wires, increased resistance, abnormal drop in the voltage of the source, such as occurs when a battery approaches the discharged condition, and various other conditions may result in the action of the ma at when not desired.

The main ob ect of the present invention is to overcome undesired operation ofv-the magnet, or relay, under various conditions, such as above referred to, and also to insure that when the movable element of the device is in its attracted or unattracted position, it

will dependably remain there. Another obcontrolled by the movable element .0 the ct when in any position, and not be subject to varying pressures, or force, such as to cause variable pressures between contacts, uncertainty or hesitancy in operation, chattering and the like. Another object is to accomplish the desired results by a simple form of apparatus which may be convenientlyand economically manufactured, and a form of the main winding 4.

Ordinarily, the number of turns in the 1929. Serial No. 364,727.

structure that will be durable and reliable in long continued use and one which avoids the use of movable parts in securing the desired results. Another object is to provide a form of construction which is applicablejfor use with alternating or direct current as the exciting energy; @ther objects and advantages will be understood from the following do scripticn and accompanying drawings.

7 Fig. 1 is a diagram illustrating one embod-- iment of the invention; and Figs. 2, 3 and 4; are similar diagrams of modified forms.

- Referring to Fig. 1, the iron or steel core,

which should, of course, be laminatedwhen used for alternating currents, is shown having a main portion 1 from which extends two legs 2 connected at their ends by a cross-piece 3, although the latter may sometimes be omitted. A main exciting winding 4 envelope the portion 1 of the core, and upon the leg 2 is another exciting winding 5 which is cumulative in its action with reference to the winding 4. On the leg 2 is another exciting winding 6, but the direction of the turns thereon is such as to tend to set up a magnetic flux in opposition to that of winding 6 will be less than that in the winding 5, but it'will, of course, be understood that the number of turns, proportions of the parts and relationship between the parts will e designed such as to suit particular requirements.

The movable element 7 of the magnet is shown pivoted at 7' and carrying insulated contactors 8, 8 adapted to engage the fixed contacts 9 in one 'tion or theother. Obviously, the mova 1e element or annature of the magnet and the contacts engaged thereby may be made in any way desired to secure the particular purposes of control. In Fi 1, the lon arrows indicate an assumed rection of t e magnetic flux due to the main windin 4, the short full line arrow the direction of ux due to the winding 5, and the short dotted line arrowthe direction of flux tending to be set up b the winding 6.

The source of energy is in 'cated at S, and

. First, assume that the supply voltage to direct or alternating current. The cumulative winding 5 is connected across the line in series with the Winding 6, although in some cases these coils may be connected in multiple with each other. connected across the line through a portion of the winding 6, but it may be connected directly across the line, or to include all or a portion of the winding 6 in series. When alternating current is used, it is desirable to connect this main winding in series with at least a portion of the winding 6, so as to reduce the watt-less current and improve the controlling eifect.

Assuming that the direction of the current in the windings at the moment considered to be such as indicated by the arrows in Fig. 1, the action which occurs to give a substantially'constant effective flux and a substantially constant force exerted by the magnet, will be understood from the following.

which the-windings of the magnet is subjected, to increase somewhat above the normal amount. Ordinarily, this would cause the pull, or attractive force, of the magnet to increase. With thisinvention, however, an increase in the supply voltage and current in the windings tends to cause an increasein flux due to the increased current in the winding 4, and also in the cumulative winding 5, but the core of the winding 5, under normal conditions, is worked at or j us't below the knee of the saturation, or permeability, curve.

Thus, the increase of flux in the leg 2 is not in proportion to the increase in current, because the magnetization is on, or above, the knee of the saturation curve. The effect on leg 2' however, is quite difierent, because the flux ensit in this le is made such that it is worked low the cc of the saturation curve, or on the so-called straight portion.

,' Increase of current in the winding 6 thus increases the opposing magneto-motive force and tends to decrease the flux in the leg 2. This offsets, or cancels, the efiect of the at-' tempted increase in flux due to the

windings

4 and 5 in the magnet. The parts, may, of

' course, be pro ortioned such that the result,

upon increase 1n sup ly voltage, is to have no efi'ect upon the res tant flux whichis' efiective in holding or attracting the movable element of the magnet. Evidently, the windings and parts can e so proportioned that an increase in supply voltage would ive an actual decrease in the attractive or pulling effect of the magnet, or an increased pull, if'desired.

Similarly, when the supply voltage drops below the normal amount, the decreased current in the

windings

4 and 5 tends to correspondingly decrease the attractive power of themagnet, but the decreased current in winding 6 causes a decrease in its opposing magneto-motive force and as the leg 2' is worked below the knee of the curve, it permits The main winding 4 is the flux in this leg to increase to such an extent that it oflsets the decreased eifectof the windings 4 and- 5, resulting in no substantial change in the attractive power of the magnet.

, Obviously, depending upon the relative numattractive power of the-magnet remains unchanged, regardless of variations in the suppl voltage of a character which should not afl ect the operation of the magnet, or relay. Of course, if the magnet, or relay, is to be operated when the exciting current attains a certain predetermined amount, or drops to a certain predetermined amount, the magnet will be designed to operate upon the occurrence of such changes and will, of course, prevent any operation, or substantial change in condition, unless such predetermined limits are reached. v r

In the form shown in Fig. 2, the form of the magnet is such as to give a return magnetic path through the part 10 extending from the upper part of the magnet and the part 10' extending to the armature 7, as distinguished from a return air path of the form shown in Fig. 1. The upper portion of the core within the-main winding 4' in Fig. 2 is made smaller than that in Fi 1, which has the advantage of economy in t e size and cost of the main winding 4. Also, the cross-piece at the lower ends ofthe

legs

2, 2 is formed with a projecting ortion 3' which tends to 4b, a cumulative winding 5a and 5b, and "an o posing winding 6a and 66, respectively.

T e armature 7a carries the flux between the poles and is adapted to be pivoted at "7 b on any suitable support and may becaused to give any desired control to arts connected therewithf The general pat of the flux is indicated by the long arrows, the direction of theflux due to the cumulative windings 5a and 5b is indicated by the short fullline arrows, and the direction of the flux tending to be set up the windings 6a and 6b is indicated by the dotted line'arrows. The main exciting windings 4m and 4?) are shown connected in series with each other and in series with one of the opposing windings 60 across the line; but the main windings may be connected in parallel with each other and connected directly across the line, or throughany portion of the windings 6a and 6b. The operation is similar to that described with reference to Fig. 1, the regulating action occurring in each of the two portions each of which comprise the two legs of Flg. 1. In some cases, sufficiently good results might be obtained by applying cumulative and opposing windings to one portion only of the d0uble-pole magnet, but in'that case the regulation will not be as close as that which may be secured by the form shown in Fig. 3.

Fig. 4 shows a form similar to that of Fig. 3, except that the core of the magnet is considerably shortened and the two main windings 4a and 4b of Fig. 3 are merged into a single winding 40 applied to the portion of the core extending directly between the twopole portions.

In some cases, the main exciting winding may be superimposed over the cumulative and opposing windings, although in that case the results, if close regulation be desired, will not be so satisfactory as when the main exciting winding or windings are located on other portions of the core. It will be understood that various modifications may be made in the form and construction of the magnet, or relay, to suit particular requirements, without departing from the scope of the in vention; and that the forms indicated and the explanations thereof are for general guidance in incorporating the invention in magnets of other forms which may be desirable for special purposes and for securing desired controlling efiects.

I claim:

1. A magnet having a core with at least two legs, a main excitingwinding on the core, a cumulatively acting winding on one leg and an opposing winding on another leg.

2. A magnet having a core with a main portion and at least two legs extending therefrom towards the movable element of the magnet, a main exciting winding on the main portion, a cumulatively acting winding on.

-' two legs joined together at their ends, a main exciting winding on the core, and an oppos-- ingwinding on one of the legs.

LA magnet having a core comprising two legs joined together at their ends, a main exciting winding on the core, a cumulatively acting winding on one of the legs, and an opposing winding on the other of said legs.

. 5. A magnet having a core, an armature, said core having two branch portions for conducting the flux of the co.e in parallel paths to the armature, a main winding on the core, and a winding on one of said branch portions opposing the main winding.

6. A magnet having a core, an armature,

said core having two branch portions for conducting the flux of the core in parallel paths to the armature, a main winding on the core, a cumulatively acting winding on one of said branch portions, and an opposing winding on another of said branch portions.

7 A magnet having a core, a movable element, said core having two branch portions for conducting the flux of the core in parallel paths to said element, a main winding on the core, a cumulatively acting winding on one of said branch portions, and an opposing winding on another of said branch portions, said portions being adjacent to each other and to the movable element of the magnet.

8. A magnet having a core forming two poles, an armature, said two poles being in proximity to the armature and at least one of said poles having two branch portions for conducting the flux of the, core in parallel paths to the armature. a main winding on the core, and an opposing winding on one of said branch portions.

9. A magnet having a core forming two poles, an armature, said two poles being in proximity to the armature and at least one of said poles having two branch portions for conducting the flux of the core in parallel paths to the armature, a main winding on the core, a cumulatively acting winding on one of saidbranch portions, and an opposing winding on another of said branch portions.

HAROUTIUN K. KOUYOUMJIAN.