US1700042A - Means for compensating the forces in voltage regulators - Google Patents

Description

Jan. 22, 1929. 1,700,042

H. GROB MEANS FOR COIPENSATING THE FORCES IN VOLTAGE REGULATORS Filed Dec. 16, 1927 en far:

k 4 fine. s hb mg Patented Jan. 22, 1929.

UNITED STATES PATENT OFFICE.

nueo once, or BERLIN, GERMANY.

, Application filed December 16, 1927, Serial No. 240,595, and in Germany December 16, 192 6.'

This invention relates to electrical regulating apparatus and more particularly to such ture or production. Another object is to provide a regulating apparatus in which a pressure responsive variable resistance is employed adapted to permit a convenient, rapid and thoroughly dependable predetermination of .the range and character of operation, as well as of compensation or balancing of the acting forces to be achieved. A.nother object is to provide a regulating apparatus of the above-mentioned character that will be of inexpensive construction, of thoroughly dependable and controllable action, and well adapted to meet the varying conditions met with in the course of manufacture or in the course of actual practical use. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims In the accompanying drawing in which is shown one of-various possible embodiments of my invention, the single figure shows in front elevation, partly in section and partly diagrammatically, an assembled regulating apparatus.

As conducive to a clearer understanding of certain features of this invent-ion, it might be noted at this point that an electric regulating apparatus embodying a pressure responsive resistance device such as a carbon pile, has many desirable advantages, but that certain difficulties are attendant upon the construction and operation of such an apparatus due,

' for example, to the fact that the resistance to compression or the reactive force of the carbon pile increases as the compression of the carbon pile increases in a manner that is not shown at A an electromagnet which may be uniform but varying. In fact, the reactive force first increases gradually as the compression proceeds and thereafter increases more rapidly as the compression advances and approaches a maximum, Ordinarily an elec troniagnet or the like is employed to relieve the pressure on the carbon pile while a spring is employed to compress the carbon pile. The forces of the electromagnet and of the spring, and the reactive force of the carbon pile should be brought into mechanical equilibrium over the entire desired range of compression of the carbon pile.

According to a preferred form of mechanism for achieving quickly such mechanical equilibrium, the spring is arranged to act upon the carbon-pile through a cord, cable or the like, resting against a suitably curved memher, the arrangement being such that by reason of the curved member the distance of the cord from the fulcrum about which the curved element pivots, and hence the lever arm through which the spring and cord act upon the carbon pile, are so changed that for each position of the mechanism the desired equilibrium of the mechanical forces acting is brought about.

This curved element is of peculiar shape due in part to the peculiar variation in the reactive force of the carbon pile; and due to various factors that either cannot be elimi-' natedor cannot be fully controlled such as, for example, variations in thematerials employed, the range of tolerances necessary in manufacture, and the like, it is exceedingly difficult, if not impossible, to employan identically curved element for all of the various regulating devices undergoing manufacture, if these devices are to have uniformly the intended or desired characteristics. Either all of the devices thus manufactured do not have the same characteristics of control or operation in the regulating action or else the individual devices and particularly the curved.

members have to be separately worked up or re-shaped or modified, mainlyby laborious hand methods, in the endeavor to achieve'the intended operating characteristics. One of the dominant aims of thisinvention is to provide a regulating apparatus in which such disadvantages as those immediately above noted are effectively overcome and in a manner thoroughly practical and simple and well adapted to meet the requirements of inexpensive and rapid quantity manufacture.

Referring now to the drawing, there is excited in any suitable manner, as for example by a function of the electrical circuit or conditions to be regulated; b Way of further example the magnet A may e excited by the voltage of, for example, a dynamo so that the regulating apparatus is voltage responsive where the v tage of the dynamo. is intended to be maintained at a constant value. A column or pile composed of carbon disks, shown at E, may be connected in the exciter circuit of the dynamo, in the above-assumed illustration, so that the excitation of the dynamo may be varied in order to control the voltage of the dynamo.

An armature Bis pivoted at K and is thus mounted to be acted upon by the electromagnet AJ A knife edge F is mounted on the armature B and acts upon the free end of the carbon pile E, the other end of which is fixed or anchored in an. suitable manner, as is diaj grammatically s own in the drawing. A spring 0 acts upon the armature B in adirection to oppose the pull on the latter by the magnet A and hence in a direction to apply pressure to the carbon ile E.

As soon as the energization of the magnet A exceeds a predetermined value, for example, exceeds a value corresponding to that of the voltage intended to be maintained constant, the magnet draws the armatureB in counter 'clockwise direction about the pivot K and against the action of the spring C, thus decreasing the pressure on the carbon column or pile E, theresistance of the latter bein accordingly varied. 7

e above action ceases as soon as the voltage value desired to be maintained constant 'isrestored and mechanical equilibriumpf such forces-as the three -hereinabove mentioned is then achieved. Moreover, such equilibrium'shouldbe achieved throughout the intended range of action of'the regulator and hence these forces should be compensated for and balanced throughout the entire operative range of movement of idle armature B.

The armature B will be seen from the drawing 'to'be substantially L-shaped, havingasubstantially upstanding arm or bracket M adjacent thefulcrum point K. Mounted uponthe bracket M isa curved element G,

- more clearly described hereinafter; the element G is provided with two threaded pins L fixed thereto, each passing through an opening in the bracket M and each being provided with nuts 0. Inter osed between the curved element G and the racket M and about the pins L are sprin N.

The element is sha d to provide an outer curved surface (in icated by the righthand curved edge of the member G) against which rests the cord or cable D, the latter being secured at its upper end to the up er end of the curved mem er G'and secured at its lower end to the spring C.

The armature B and hence the curved member G carried by it are fulcrufned at K, the fulcrum point being preferably in the form substantially of a knife edge, as shown in the drawing. The curved surface pro vided by the member G is so shaped that as the latter swings about the pivot K the lever arm through which the spring G 'acts changes curvature of the member G is so chosen that throughout the range of action of the regulator the force exerted by the spring continually counterbalances the pull of the magnet plus the reactive force of the carbon pile. Substantial equilibrium or balance of the parts prevails in each position of the arma- .ture throughout its entire range of movement. The member G is given a curvature appropriate to achieve the aboize-described actions, it being understood that the member G may be made in large quantities and of identical construction and shape throughout,

However, becausev of various factors due, for example, to uncontrollable variations in the material used, non-uniformity of action of the various springs, the magnetic qualities 0 the iron used in the ample such variables as occur within. the range of tolerances necessarily permitted in the construction and manufacture of the various-parts, it is possible. that the member G ssible variation in' Jnagnetic circuit and by way of further exeven though initially carefully predetermined as to curvature, has its action modified by such factors as'above noted by way of-example. Accordingl when the regulating apparatus is assemb ed and-tested or in-.

stalled to give it its intended operating characteristics, these factors are dependably overthe bracket M, the relation of the predetermined curved membervG to the parts with which it coacts. The pins L will be seen to be spaced substantially and by means of the nuts 0 and the coaction therewith of the springs N, an upper point and substantially a lower point of the curved member G (corresponding respectively to the points of attachment of the'pins L come by predetermining', by means of the "manner in which the member G ismounted on and corresponding substantially to the two extremes of the range of operation of the regulator), may be empirically predetermined to achieve file intended force-compensating or equilibrium -establishing action above-described, and if thus two materially spaced points of the curved member G corresponding to two difierent points in the range of action of the apparatus are thus predetermined, it is found that, due to the predetermined curvature of the member G, the remaining points in the range of operation of the apparatus will substantially bring about the intende action of the apparatus. I

Thus, it will be seen that there has been provided in this invention a thoroughly practical and reliable regulating apparatus well adapted to meet the requirements of not only hard practical use but also of inexpensive manufacture on a large scale and that the various variable factors that have to be contended with in the manufacture of such apparatus are reliably overcome in a thoroughly simple and inexpensive and economic manner.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or show'n'in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In electrical regulating apparatus, in combination, a pressure controlled variable resistance element, a coil, a pivoted member acted upon by said coil and mechanically connected to vary the compression of said resistance element, a spring, means connecting said spring to said member and including a flexible cable connecting said spring to said member and a curved element adapted to change the lever arm through which said spring acts as said pivoted member moves about its pivot, and means mounting said curved element upon .said pivoted member and including a pair of devices spaced lengthwise of said curved element, and means for predetermining the displacement of said devices from the 4 fulcrum of said pivoted member.

2. In electrical regulating apparatus, in combination, a pressure controlled variable resistance element, a coil, a pivoted member acted upon by said coil and mechanically connected to vary the compression of saidresistance element, a spring, means connecting said spring to said member and including a flexible cable connecting said spring to said member and a curved element adapted to change the leverarm through which said spring acts as said pivoted member moves about its pivot, means mounting said curved element upon said pivoted member and including an arm on said pivoted member, and means connecting said curved element to said arm at at least two spaced points of said curved element and adapted to permit predetermination of the displacement of one of said points from said arm.

3, In electrical regulating apparatus, in combination, a pressure cont-rolled variable resistance element, a-coil, a pivoted member acted upon by said coil and mechanically connected to vary the compression of said resistance element, a spring, means connecting said spring to said member and including a flexible cable connecting said spring to said member and a curved element adapted to combination, a pressure controlled variable resistance element, a coil, a pivoted member acted upon by said coil and mechanically connected to vary the compression of said resistance element, a spring, means connecting said spring to said member and including a flexible cable connecting said spring to said member and a curved element adapted to change the lever arm through which said spring acts as said pivoted member moves about its pivot, means mounting said curvedelement upon said pivoted member and including an arm on said pivoted member, a plurality of pins on said curved element, and means securing said pins to said arm and adapted to permit adjustment of said pins and hence of said curved element in a direction toward or away from said arm.

5. In electrical regulating apparatus, in cgmbination, a pressure controlled variable resistance element, a coil, a pivoted member acted upon by said coil and mechanically connected to vary the compression of said resistance element, a spring, means connecting said spring to said member and including aflexible cable connecting said spring to said member and a curved element adapted to change the lever arm through which said spring actsas said pivoted member moves about its pivot, means mounting said curved element upon said pivoted member and including an} arm on said pivoted member, a plurality of pins on said curved element, and means in uding spring means for securing sai-d'pins 0 said arm and adapted to permit adjustment of saidlpins'and hence of said curved element in a direction toward or away from said arm.

6. .,In electrical regulating apparatus, in combination, a pressure, controlled variable. resistance element, a coil, a pivoted member acted upon by said coil and mechanically connected to vary the compression of said resistance'element, a spring, means connecting said spring to said member and including a flexible cable connecting said sprlng to said member and a curved element adapted to change the lever arm through which said spring acts as said pivoted member moves about its pivot, and means mounting said curved element upon said pivoted member adapted to permit predetermination of the relation of said curved element to said pivoted member.

7. In' electrical regulating apparatus, in combination, a compressible carbon pile; electromagnetic means for relieving the pressure thereon; spring n'icansacting to increase the pressure on said carbon pile; a member of predetermined curvature for compensating for the variation in the reactive force of said carbon pile; and means mounting said curved member in operative relation to said spring, electromagnetic means, and carbon pile adapted to permit predeterlnination of its relation thereto." p

8. In electrical regulating apparatus, in

combination, a compressible carbon pile, elec troma netic means for relievin the ressure a thereon s rm" means actm to mcrease the i F- pressure on said carbon pile, means including a member of predetermined curvature for changing the lever arm throu h which said spring acts upon said ca rbon-p1le, and means] mounting said curved memberadapted to.per-

mit predetermination of its action in changing the lever arm of the sprin 1 9. In electrical regulating apparatus, in combination, a compressible carbon pile, an electromagnet having apivotedarmature provided with an arm extending substantially at ri ht angles thereto and adjacent j the pivot of said armature, means connecting said armature to said carbon pile to permit change in the pressure on the latter as said Y armature moves, a spring, means connecting said spring to said arm comprising a flexible cable and a member of predetermined sha e movable with said arm and against which said flexible cable rests, said-member being shaped to change the lever arm through which said spring acts, and means mounting said member of predetermined shape on said arm and adapted to permit at will a change in: the displacement of said member relative ber of predetermined sha e movable with said arm and against whic said flexible carblc rests, said member being" shaped to change the lever arm through which said spring acts,

and means at two spaced points for securing said member of predetermined shape to said arm adapted to permit predetermination at "will oft-he displacement individually of said spaced points of said member from the pivot of said armature.

In testimony whereof I have aflixed my signature.

l-IUGO. GROB.

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