US1353865A - Speed-indicating instrument - Google Patents

Description

W. VAN GUJLDER. SPEED lNDICATfNG HIS APPHCATION FIL TBUMENT.

BHJNEIT, IQIB.

PatentedSept.

UNITED STATES PATENT OFFICE.

WALTER. VAN GUILDER, OF CHICAGO, ILLINOIS, KSSIGNOR TO STEWART-Wm SPEEDOMETER CORPORATION, OF CHICAGO, ILLINOIS, A OORZPURATION-OF VIE- GINIA.

SPE'EBiNDiCATING INSTRUMENT.

Specification of hitters Patent.

Patented Sept. 28, 1920.

Application filed June 1?, 1918. Serial No. 240,555;

To all whom it way concern.

Be it known that I, llhrxrnn VAN Gijmnnu, a citizen of the United States, residing at Chicago, in the county of Cook and the State of Illinois, have invented certain new and useful Improvements in Speed -Irulieutlng Instruments, of which the following is a specification. reference being had to the no (rompanying drawings, forming a part thereof.

The purpose of this invention is to pro vide on improved construction of speed in (lit-rating levioe having the magnet fixeththat is, non-rotating, the rotating element being a multi-polnr armature which may be comparatively light thereby adapting the instrument for indicating the speed of shafts to be rotated by light power, and Whose speed of rotation would be materially reduced by the resistance of n speed indi" eating device hm lug heavy parts to be rotated. It consists in the elements and 'l'en" tures of eonetrurtion shown and (leseril'sed indicated in the claims.

In the drawings:

Figure l is an axial section of an instrument embodying this invention.

Fig. is a front elevation of the some with the cover member removed.

Fig 3 is a section at the line. 3-3, on Fig. l. i

Fig. 4 is a section at the line. 4-4. on

Fig. l.

The inetrument shown in the drawings comprises a casing, l, in which there is supported rigidly n magnet mount, 2, which is made of non-magnetic metal in the general form of a cup having at the top edge or front edge an outwardlyextending flange, a. by which the mount is supported on the casing. The magnet element comprises two semi-annular magnets. 4-. 4, whirh are fitted within the cup-shaped mounzt, being lodged upon the bottom or back diaphragm thereof and against the circular wall, said magnets while culled semi-annular, eing in fact each slightly less than a halt circle. so that when they are positioned are stated in the. cup, two equal inter-polar go is exist. said magnets being placed with t eir poles of fpposite name respectively facing each other at opposite sides of said gaps. Said mount is preferably a casting and formed with inwardly-extending radial projections 22%, from its annular walLventermg the interpolar gaps between the two magnets as stated and thereby further securely position the magnets in the mount. For further securing the magnets in the mount there is 'the opposite side of the magnets from the bottom web of said mounts.- For assembling the parts as described and engaging the annular retaining plate, 5, peri berallv with theoup-shaped mount as described, the retaining plate has any convenient number,as shown, two diametrically opposite each other.0f peripheral projections, 5, and the TnOUIlt has two wrrespondingly situated notches, 2 2. extending in from its open edge a short distance, each connecting with a groove, 2, formed in the inner wall of the cup-ehapedmount; so that said retaining plate may be introduced into position by entering its said projections through suid notches to the bottom thereof, and then rotating the plate to engage the projections with said grooves, as seen in Fig. 2. On the back wall of the case. 1, there is mounted on inunruly-projecting bearing stud, 7, on which there is journaled a gear, 8, which is conveniently retained on the stud by a cap screw. 9. This gear carries a multi-polar nrnmture, 12. at the center of which it is secured to said gear for rotation thereby. As shown. the armature has an even number of poles, equally spaced, so that the relation of the poles to the two diametrically-opposite inter-polar gaps of the magnet are at all times identical; that is to say, the sum of the distances of the armature poles from 17 and 18, there are provided suitable jeweled bearings, 17 and 18, for the op osite ends of the spindle, 16. For the sa e of complactness the dra element of the drag disk is depressed at its central part so that it is secured to its spindle between the planes of the opposite sides of the magnet element, that is to say, in the central space of the annular structure comprising said two semiannular magnets. dial plate, 20, is mounted upon the magnet mount, having a central opening through which the spindle extends for carrying in front of said dial plate an index pointer, 21, mounted on the spindie back of the spindle bearing in the arm, 18. The front of the case may be closed by a cover, 25, comprising a transparent crystal, 26, through which the reading of the instrument may be observed. For rotating the rotatable armature there is jour naled in the case a shaft, 28, havin at its inner end a gear, 27 meshing with t e gear, 8, the outer end of said shaft being ada ted for driving connection in a manner w ich will be understood from the drawings without explanation.

For calibrating the instrument there is mounted in relation to each of the semiannular magnets a shunt terminal pole piece, 3( of soft iron which is conveniently formed angle shaped as seen at Fig. 2, having one flange provided with a slot, 31, by which the pole piece is adjustably mounted upon the ring, 5, by means of a screw, 32. The range of adjustment of the pole piece with respect to the magnet is such as to permit the flange, 33, of the shunt terminal, 30, to project more or less across the inter-polar gap of the magnet, and thereby be ada ted to conduct a larger or'lesser portion '0 the flux across the gap, for diminishing the amount of flux which is diverted by the poles of the rotating multiolar armature through the drag element, t ereby varying the drag eiiect. This, it will be seen, will enable the assembler of the machine to make such adjustment as may be necessary to cause a givcn speed to produce a given indication upon the dial, notwithstanding variution in the strength of the magnets, and variation in the resistance of the biasing spring. That is to say, it facilitates adaptu tion of the biasing spring to the strength of the magnets. by modification of the proportion of the magnet-strength which becomes effective for producing drag.

For the purpose of adopting the instrument to he automatically compensated tortempen ature changes and also to automatically compensate for changes in the magnet strength the interpolar gaps between the magnets, which as stated are in the main occupied by thc substance of the mount, which has the projections, 2, for engaging said intcrpolar gaps to position the magnets fixedly are partly opened by cutting away the material of the mount inangular form as seen at 2, and for each gap there is provided an angular or V-shaped soft iron armature piece, 35, mounted upon one end of the iii-metallic spring carrying arm, 36, the other end of which is secured to the mount, so that said sojt iron armature piece may protrude more or less deeply into the iuterpolar gap according to the curvature of the bimetallic arm which carries the armature, which is effected by the change of temperature. The member of the iii-metallic arm having the higher cocflieient of expansion being on the inner side, as the temperature rises the arm will be straightened with the effect of carrying the armature piece back out of the gap, and when the temperature falls it will be more curved, carrying said armature piece toward or into the gap; which it will be understood will have the client of diverting a larger amount of the magnetic flux from the rotating armature as the temperature falls, and ermitting a larger portion of the flux to be iverted b the rotating armature so as to be out by t e drag element as the temperature rises; thus compensating for the diminution 'of drag which results from the rising temperature and the increase which results from the falling temperature.

The arms, 36, being as stated, s ring arms, are adapted to yieldingly resist t 1e tendency of the V-shapedarmature, 35, to move toward the magnet poles under the attraction of the magnet; and upon any decrease in the magnets strength, the armature piece. 35, will be retracted by the spring arm away from the magnet poles, thereby diminishing the proportion of the magnetic flux passing through said armature piece, 35, and correspondingly increasing the proportion of flux passing through the poles of the revolving armature, 12. Similarly, any increase in the magnets strength causing the armature piece, to approach the magnet poles, diminishing the proportion of flux passing through the revolving armature. It will be understood that these changes of proportion of flux passing through the rcvolving arma ture, correspondingly affects the drag on the drag element, 1!), increasing the drag relatively upon decrease of magnet strength, and decrealing it relatively upon increase of magnet strcngth, thus automatically compensating for such changes in magnet strength.

I have indicated that the devi e liS "'ii7t l has two interpolur gaps and a r tating armature ll l' 'i'idill with an even number of poles; but it Wiil be obvious that the result sought by this feature of The constru tion requires only that the number of armature poles bc a multiple of he numhcr of magnet gaps, there being a plurality of said gaps. The preferred"number of gaps being two, there will be an even number of armature poles, as specifically shown and descri l'Jtt l.

I claim:-

I. In a magncticspccd indicating instrument in combination with a non-rotating magnet; the multi-polar armature device mounted for rotating its polespast the magnet poles; an electrically conductive drag disk positioned and pivotally mounted for oscillation in a plane intermediate the magnet poles and the path of rotation of the armature poles, and means for biasing the disk in respect to the direction of its oscillatory movement; the magnet element comprising a plurality of ei willy-dimensioned magnets each having both its poles in the same plane transverse to the axis of rotation of the. armature device, and the poles of each proximate respectively to the oppositely-named poles of another. for forming in a circle about said axis as many interpolar gaps between poles of opposite names of dit'lcrcnt magnets, as the entire number of magnets of the nu gnet device; the mount for the magnet consisting of a uoirmagnetic substance encompassing and occupying the inter-polar gaps otsaid magnets, and a lateral annular retaining plate at one side of the magnets peripherally engaged with said mount.

2. In the structure defined in claim I. toregoii'ig, the mount having a bayonet-lock slot and the plate having a peripheral projection adapted to he entered through and engaged with said bayonet lock slot by angular movement of the plate, for securing the magnet against disphu-cmci'it of the mount.

3. In a magnetic speed indicating instru ment comprising a fixed magnet element having an interpolar gap,- a revolving interrupted armature. and a drag element intcrmediate the magnet and said armature; a temperature compensating device consisting of a soft iron armature piece and a bi-metallic arm Which carries said armatur' piece on its movable end proximate to the interpolar gap of the magnet for moving it relatively to said gap upon temperature changes deflecting said iii-metallic arm.

4. In a magnetic speed indicating instrunient comprising a fixed magnet element having an interpolar gap, arevolving inter-- rupti-d armature, and a drag clement intermediate the magnet and said armature; a calibrating deviceconsisting of an adjustable pole piece or shunt terminal mounted adjacent to one pole of the magnet and adjustable relatively thereto toward and from the other pole across the interpolar gap.

5. In a magnetic speed indicating instrument such as defined in the last claim foregoing, the magnet element comprising a plurality of arcuate elements positioned in the same plane with substantially equal interpolar gaps, one of the magnet poles at each gap being provided with the adjustable pole terminal or shunt.

6. In a magnetic speed indicating element in combination with a magnet element having an interpolar gap, a temperature compensating element consisting of a soft iron armature and a temperature-responsive carrier for the same mounted at one point fixedly with respect to the magnet and carrying the soft iron armature at a point on said carrier which moves responsively to temperature change and at. a position for moving in one direction toward both magnet pole. and in the opposite direction away from both magnet poles.

T. In a construction such as set out in claim (3 foregoing. the armature carrier being a bi-metallic arm.

8. In a device such as defined in claim 6, the compensating armature carrier being a. bimetallic arm, mounted at one end fixedly with respect to the magnet and carrying the armature at the other end in the plant! of the magnet toward and from the interpolar gap.

9. In a magnetic speed indicating instru ment in combination with a magnet element, a drzu element and a flux deflecting armature tor deflecting the tlux through the drag element. a magnetstrength-change-compensating device comprising a soft iron armature element positioned proximately to the magnet gap and a sprin support for the same mounted for yielting toward both poles in one movement and reacting away from both poles in the opposite movement.

10. In a structure such as defined in claim 9 foregoing, the magnet being fixed and the flux-deflecting armature being multi-polar, positioned laterally with respect to the magnet and rotating, and the compensating armature being carried by the spring support for movement radially toward and away from the interpolar gap of the magnet.

In testimony whereof, I have hereunto set my hand at hicago, Illinois, this 14th day of June, 1918.

- \VALTER VAN (iUILDER.

Images