US1778835A - Induction timing motor - Google Patents

Description

Oct. 21, 1930. A. R. RUTTER 1,778,835

INDUCTION TIMING MOTOR l Filed OC'b. 28, 1926 2 I O .f /2

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'Patented Oct. 21, 1930 UNITED "sT-Arasv PATENT ori-IcaA ARGYLE R. BUTTER, OF FOREST HILLS, PENNSYLVANIA, ASSIGIN'OIB T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA INDUCTION T IMING Moron Application mea october 28, 1926. serial no. 144,770.

My invention relates to inductiontiniing motors usedindemand attachments for inductionwatthour demand meters and more particularly to means for adjusting the intensit-y of electromagnetic iux in the field magnets thereof.

An object of my invention istoprovide means for accurately adjusting the flux in i 'tensity'of theelectromagnetic fields of such" instruments as those above specified.-

Another'object of my invention is to provide adjusting means, of the above indicated character, that shall be easily and siinply made in ield service. so

It is necessary that the timing motors' .used in demand attachments for induction Watthour meters shall rotate at a definite speed, sincea predetermined number of revolutions of the disk of the motor determines the interval of timeduring which certain gears of the mechanism are maintained in engagement. Any deviation in the speed of the disk will cause -a correspondingerror in the demand register. Therefore, I provide means for adjusting the speed of the disk to insure the proper functioning of the demand-indicating device. j

Such adjustment is affected by short-circuiting the magnetic pole elements of theenergizing electromagnet by a magnetic-flux conductor, thereby adjusting the intensity of the electromagnetic field which influences the disk.

In the prior art, the intensity of theelectromagnetic field has been adjusted by varying the quantity of current flowing in the coil of the electromagnet, by means of an adjustable resistor in series therewith. That method of adjustment was less accurate than j the one herein described and had the further disadvantage of requiring the joint between the resistor and a, tap conductor on the coil, to be resoldered every time an-adjustment Wasmade.

In practicing my invention, I provide an adjustable screw'between poles of the electromagnetfor partially vshort-circuiting the electromagnetic field which might influence the disk.

Figure 1 ofthe accompanying drawings', is

Fig. 2 is a side elevational View of the electromagnet structure shown in'F ig. 1. if

A timing induction motor embodying my invention comprises, in general, a magnetizable core member 1, an armature 2, a poten;

tial winding 3, a secondary coil 17, a tertiary coil 4 and a screw 5.

The magnetizable core 1 is constructed of a plurality of laminations having acentral portion 6 and side portions 7 and 8 that are integral with a base portion 9 at one end and spaced apart at their free ends b air-gaps 10 and 11. A slot 12 is provide near-the free end of the central portion 6, and the side portions 7 and 8 are provided with laterally extendingyhorns 13 and 14, respectively. The potential winding 3 is disposed around the central portion 6in rectangular L) windows 15 and 16 in the side portions 7 and 8. A secondary coil 17 surrounds coil 3 4in the rectangular Windows 15 and 16 and is connected Ain series with the tertiary coil 4 and a resistor y19. The tertiary coil 4 is 4disposed around the free ends of portions 6 an 8 and in slot 12.r

The armature 2 is mounted on a 'shaft 18 and is disposed adjacent the ends of portions 6, 7, and 8 in a plane parallel to their faces and separated therefrom by an air-gap.

The screw 5 bridges the air-gap 10 in suitable screw threads, located in the free ends of portions 6 and 7. When turned by means of a slot 20 in the head thereof,'it serves to increase or decrease the length of the fluxshunting path between the lateral areas of the portions 6 and 7, vthereby varying the effective fiux that influences the disc. Y

lhen the winding 3 is operatively connected to an electric circuit (not shown), currents are induced in secondary coil 17 which flow through the tertiary coil 4, setting up 4lines of flux in the core member 1 that emanate from the free ends of the lportions 6, 7 and 8, and traverse the disc orarmature'2 to effect its actuation. A primary adjustment of secure a proper speed of the armature, is made by adjustment of resistor 19 which regulates the quantity of current to .energize coil 4. This primary adjustment is then refined to a high degree of accuracy by varying the lengthV of the screw in contact with the threads set in the lateral areas of portions 6 and 7. By

thus .varying the short-circuited flux to the proper ua'ntity by means of the screw 5, the

speed-o the armature 2 may be very accupreferred form, it will be understood that various modifications may be made without departing .from the spirit and scope of the invention as set forth in the appended claims.k I claim as my invention: l l 1. A timing motor of the induction-meter type 'comprising a three-legged core, the three legs being joined at-the back end"` and separated by gaps at the front end,.the central legl having a slot in its front end forming. two

.central halfpoles,l a single-phase exciting winding tending to give the front end of the central leg a polarity substantially opposite to thatkof the front ends of the other legs, a de-phasin winding embracing the 'front end of one of t couter legs and one of the central half-poles, and a diskarmature pivoted to rotate with its Mface closev to the front ends of said legs, characterized. by a screw-'adjusted magnetic-{iux-varying meansdisposed in one v of the gaps between the front end of the cen-v ral leg and the front end ofone of the side egs. j

2. A timing motor of the induction-meter type comprisinga three-legged core, the three legs belng joined at the back endand separated by gips at the front end, the central leg-having a slot in its front end forming two central half-poles, a single-phase exciting windin disposed on the central leg at a point remove from its front end, a 'secondary winding disposed in transformer relation to the exclting winding, a de-phasin winding embracing the front end of one o the outer l legs and one of the central half-poles, a rheo'- stat connecting the de-phasing winding to `be energlzed from-the secondary winding, and a disk armature pivoted to .rotate with its vface close to the front ends of said'legs,char acterized by a screw-adjusted magnetic-Huxvarying means disposed in one ofthe gaps between the vfront end of the central leg and the front end of one of the side legs.

3. A timing motor of the induction-meter type comprising a three-legged core, the three legs being joined at the back en'd and separated by gaps at the front end, the central leg having a slot in its front end forming two central half-poles, a single-phase exciting Winding tending to give the front end of the legs being joined at the back end and sepa- *l rated by gaps at the front end, the central leg having a slot in its front end forming two central halfpoles, a single-phase exciting winding disposed on the central-leg at a point removed from its front end, a secondary Wiuding disposed in transformer relation to the exciting winding, a de-phasing winding embracing the front end of one of the outer legs and one of the central half-poles, a rheostat connecting the de-phasing winding to-be energized from the secondary'winding', and a disk armature pivoted to rotate with itsface close to the front ends of said legs, characterized by a magnetizable screw fitted laterally and adjustably into the gap between the front end of the central leg and the other one of the outer legs.

In testimony whereof, I have hereunto subscribed my name this l26th day of October,

l ARGYLE R'. BUTTER.

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