USRE14733E - Electric meter - Google Patents

Description

Reissued Oct. 7, 1919.

' J. L. AXEN.

' ELECTRIC METER.

APPLICATION FILED JUNE 14, I919.

2 SHEETSSHEET l.

J. L'. AXEN. ELECTRIC METER. APPLICATION FILED JUNE 14, I919. Reissued Oct. 7, 1919. 14,733,

2 SHEETSSHEET 2.

' Q Muowwtoz xvi/ Mano I M %13 z Y'UNITED STATES PATEN OFFICE.

Tom: L. AXEN, or DETROIT, MICHIGAN, ss'srenoa To NATIONAL GAUGE & EQUIPMENT comm, or LA cnossn, wrscoivsm, A CORPORATION or WISCONSIN.

ELECTRIC METER.

Specification of Beissued Letters Patent. Reissu-ed Oct, 1919,

orlirlnal No. 1,247,818, dated November 27, 1917, Serial No. 148,814, filed February 13,- 1917. Application for w reissue filed June 14, 1919. Serial No. 304,825. I

rent, as when the instrument is in a short circuit, will not have any permanent effect or influence on the normal resident polarity of the interrelated parts.

An object of my invention is to provide a simple, effective and permanent means for calibrating the instrument. 1

Other and further objects -of my invention will become readily apparent to persons skilled in the art from a consideration of the following description when taken in conjunction with the drawings, 'wherein- Figure 1 is a front elevation of the instrument.

Fig. 2 is an enlarged front elevation of the instrument with the dial removed.

Fig. 3 is a sectional view taken on line 33 of Fig. 1.

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3 showing the instrument with the casing removed.

Fig.5 is a sectional view taken on line 55 of 'Fig. 3.

. In the accompanying illustrative embodiment of my invention I have shown an ammeter for measuring and indicating the direction of an eleetriccurrent.

The instrument illustrated is of the polarity indicating type wherein the needle or index is normally poised in' the'center or zero point of the scale, to be deflected to' one side or the other of the scale depending upon the direction of current flow, the amount of deflection in either direction indicating the amount of current passing through the instrument.

Instruments of this ty e, wherein the index needle is poised or in uctively influenced by an adjacent permanent ma et have always heretofore been open to t e danger of demagnetization of the permanent magnet or reversal of its polarity dueto the magnetic efiects produced by an abnormal current flowing through the instrument coil in excess of its intended capacity. The efl'ect of such an occurrence is to destroy the stability and calibration of the instrument and to impair or minimize its usefulness.

In my improved construction I provide a permanent magnet to inductively influence or poise the needle but instead of placing it in close proximity to the currentcarrying coil, as is usual in instruments of this character, I have located it as far away therefrom as environments will, permit, and be yond the efleotive reacting field that may be produced by an excessive current flowing through the coil. To each pole of the permanent magnet I attach relatively small thin or attenuated strips of cast iron or other permeable material, of low magnetic retentiveness, the strips possessing considerable magnetic reluctance owing to their length and relatively small cross section. The magnetic flux through these relatively thin long pole pieces is suflicient for the desired purpose but they interpose too much magnetic resistance, between the coil and the permanent magnet to permit suificient flow of magnetism from the coil to the permanent magnet to de-magnetize the same or reverse its polarity.

A main feature of the-invention is in the employment of a permanent magnet in such spaced relation to the current carrying memher and with such conductors extending from the magnet to a point adjacent the current carryin member and so arranged as to per mit su cient flux to flow from the magnet, but prevent an excessive flow from the said coil to the permanent magnet. The method' employed to protectthe permanent magnet is not by varying the magnetic field out is founded upon the proper location of the magnet and the diverting of an' excessive flow of magnetism by means interposed between the magnet and the current carrying member.

Referring now to the specific embodiment of my invention which I have illustrated for the purpose of complete disclosure, the numeral 10 indicates a cup shaped casing having at its front a flange 11 for attachment to an instrument board, the opening in the I to . flange 11 being overlaid b a glass 12. Telescopingwit'hin the rear the casing 10is a cup shaped base member-13, the peripheral flange 14 of which is secured to the casing 10 by means of the screws 15. The instrument parts are all carried by the base 13 so that when removed fromthe casing all of theinstrument parts are open for inspection or repair. 2 1

The movable parts of the indicator are carried on a stafi 16 journaled at its upper end in a bearing 17 carried at the a ex of a I V-shaped bar 18, the outer ends of w 'ch are. fastened by screws 19 to the vertical posts20 J cast'inte with the base 13. Thedial or face 21 o the instrument is secured by means of screws 22 to the wings 23 formed integral 5 with the V-shaped bar 18. The needle orpointer 24 is secured as at 25 near the upper 20. end of the 'stafi beneath the dial andpro ects through a small arcuate opening 26 therein for presentation at the outer face of the dial, the pointer cooperating with the arcuate scale indicated at 27.

The lower end of the stafi 16 sets in the adjustable bearing 28 carriedin the bottom 'wall of the base 13 and lying at the apex of a fan shaped recess or air chamber 29 bounded by the walls 30 which extend to the peripheral wall .14 of the base. -A cover plate 31 overlies the fan shaped recess and v1s secured in position by means of a screw 32. A blade or vane 33 is mounted upon the lower end portion'of the staff 16 and is of a size but slightly less than the transverse area of the recess. This blade operating within the closed chamber serves as a dampener, rendering the instrument practi- "-call deadbeat and insuring asteady, even rea ing.

, A short diamond shaped armature 34 of magnetic material is mounted on the shaft between the cover plate 31 and the needle" mounting 25" and is influenced by a current carrying coil which comprises a flat strip of metal indicated in general by the. numeral 35. The coilfi terminals' 36, 37, project I through the rear wall of the basev 13 and aresecured at their inner ends to the opposite I ends '38, 39.-of the coil 35. As heretofore stated the coil comprises a flat'strip of metal and extends from one end 38 upwardly as at 40 into a plane arallel with the armaone end 40 to a oint 41 beyond the opposite end of'the need e, where it is bent upwardly Y as at 42 and then backwardl as at-43 parallel with the first leg but a ove the armature. At the opposite end of the leg 43 it is again bent downwardly, as at 44, and .is

I proximately"midwaybetween' the armature V nd the lower course of 'the- .coilv and then extends outwardly away from the coil as at .165 46 terminating as at 39 where it is connected tom wall of thebase. H p fed at theside of the base 0 posite to the armature 34 and coil 35 an is positioned returned upon itself as at 45- in a plane a p-.

to theterminal 37 The three layers of the coil are erforated as at 35 to permit the passage t erethrough of the staff 16.

A short bar 47 of permanently magnetized 7 metal is bent in an arc to conform to the cur- 70 vature of the periphery of the base and is secured at its opposite ends: by screws 48 upon the posts 49- cast: integral with the bot- The magnet is mountjust as close to the farthest edge ofthe-in: strument base. as the environments will permit. From the poles 50,51 of the magnet I have extended thin strips of cast iron or similar permeable materlal of low magnetic retentiveness, their ends being connected "directly to the magnet-47 by means of the magnet mountiii screws 48. These strips 52 extend from t e poles of the magnet up- '85 wardly and .away from the poles into a plane a short distance above the upper course 43 of the coil 35. Theextreme ends 53 of" the strips 52 are bent' inwardly toward the shaft so as to lie above) the armature 34 at opposite sides of the staif. The ends are layer of coil 35 is of such size and sha e that-,.

the armature 34 may be inserted t said top layer flat-wise;

Havlng thus described my invention, what rough I claim is 1. An electric. current indicator comprising acurrent carrying member, a member susceptibleto magnetic influence associated therewith, said members. being relatively movable, a erm'an'ent magnet positioned re' mote from ire current carrying member, and relatively attenuate pole pieces extending from the poles of the magnet into the field of influen'ce of said currentcarrying member and incapable of transmitting 'suflicient magnetic flux from said member to reverse the polarity of the magnet. him 34 and below t e same extendmg'from .2. An electric current. indicator eompris--. 1 ing' a movable member susceptible to mag-' netic influence, a current carrying conductor associated therewith, a permanent magnet positioned remote from the conductor, and

metallic strips of small cross section extendmg from the-polesof the magnet into close proxlm lty tothe-movable member and incapable-of transmitting sufficient magnetic 'flux' from .said conductor to reverse the j polarity of the magnet.

3; An lectric current indicator compris-hlso ing a movable member of magnetic material, an electrical conductor associated therewith, a permanent magnetpositioned remote from the coil, and metal pole ieces of .low mag-' netic retentiveness exten ing from the poles of themagnet into close proximity tolthe' ;-mov'able -memb'er-and incapable of transwith, anindicator, carried by the movable"- member, a permanent ma I mitting' suifi'cient magnetic flux from saidconducto'r reverse thepolarity of. the magnet. a

ber of magnetic vmaterial associated thereet mounted at a point remote from the 0011, and attenuated .pole pieces extendin of the base and mounted at the side oppo- 'site to'the magnetic member, and thin strips of magnetic material of small cross section close proximity to t e movable member and incapable of transmitting sufficient ma etic flux from the coil to reverse the polarity of the magnet. 1 5. An electr'iccurrent indicator compris ing a current carrying coil, a movable member of magnetic material positioned adjar cent the coil, an indicator carried by the movable member, a permanent magnet mounted"v at a oint remote from the coil,

and metallic p0 e pieces of low magnetic re.'

tentiveness and small cross section, extending from the magnet into close roximity to the movable member and in'capa 1c of trans mitting -sufiicient magnetic flux from the coil toreverse the polarity of the magnet.

6. An electric current indicator compris-- ing a base, a ma etic member pivoted near one side thereoi a current carrying coil associated'therewith, a permanent magnet mounted onthe base at the side opposite'to' the ma etic member, and thin strips of magnetic material of small cross section extending from the poles of the permanent magnet into'close proximity to the magnetic member and incapable of transmitting suflicient magnetic flux from the coil to reverse the polarity of the magnet.

7 Ali electric current indicator comprismg a clrcular base, a magnetic member p1v otedanear one slde thereof, a current carrying coil associated therewith, a short bar of permanently magnetized metal curved to a conform to the; curvature of the periphery extending from the poles of the permanent magnet into close proximity to the magnetic member and incapable of transmitting suite cient magnetic flux from the coil toreverse the polarity of themagnet.

ing a movable magnetic member, an electrica conductor 'associatedtherew th, a per-'- larity of the magnet.., f

' 9. ,An electric current indicator compris-' electric current indicator compris ing a current carrying coil, a movable mem-- from the magnet .into

8. An electric current'indicator compris- -manent magnet, and flexible pole pieces extending from ,the poles of the'magnet into close proximity tothe magnetic member and incapable of transmitting .suflicient magreverse'the po-f ing a current carrying member, a member- Susceptible; to magnetic influence'associated thegewith, said members being relatively mo able, a permanent magnet and flexible polepieces extending from the oles of the magnetinto close proximity to t e members.

10, In a current indicating device, .the'

combination of acurrent carrying member with a member associated therewith, said" membersbeing relatively movable, a erma nent magnet, a flux conducting mem' er for carrying a directin flux from said permanent magnet to sai second member so proportioned as to -limit effectively the passage to the magnet of demagnetizing flux ltgo the current of the first mentioned mem- 11. In a current indicating device, the

due

combination of a current carrying member with a member associated therewith, said members being relatively movable, a perma nent magnet, adjustable flux conducting members for carrying a; directing flux from said permanent magnet to said second men-- tioned member so proportioned as to limit efi'ectively. the passage to the magnet of demagnetizing flux 1n the various positionsassumed by said flux conducting members dueto the first mentioned member.

12. In a current indicating device, the combination of a current carryin'gmember with a member associated therewith, said -members bein relatively movable, a permanent magnet, uxconductingmembers capable of adjustment in two directions carrying magnetic flux so proportioned as to limit efiec tively the passage to the magnet of demagnetizing flux in the various p0 sitions assumed by said flux conducting members.

13. In a current indicating device, the combinatiom of a current carrying member with a member associated therewith, said members being relatively movable, a ermanent magnet, a flux conducting mem r 'for carrying a directin flux from saidpermanent magnet to sail? second member so proportloned and placed as to prevent a-detr-imental'amountoffiux to as to'said magnet due to the current 0 said. first mentioned member.

Signed-at La Crosse, Wisconsin, this 5th day of June, 1919.

' JOHN L. AXEN.

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