US1331815A - Automatic electric regulating device - Google Patents

Description

A. KAZENMAIER.

AUTOMATIC ELECTRIC REG'ULATING DEVICE.

APPLICATION FILED OCT-23, I918;

Pawn-tad Eebi, 1920.

MMMAVL,.. I 'aNVEN n R nn frnp san -arse AUGUST KAZ ENMAIEB, 0F STUTTGAR GEEK-MANY, BY .EEESIilIJ AS$IG-N- MENTS, 'IO' AMERICAN BOSCH MAGNETO CORPGEJLTIOZEI, QEZIEW "203K, N. Y., A.

QORPDRATION OF NEW YQlZtK.

AUTOMATIGELIJCTBIC ItEG'ULATITUIfi- BET/26E.

Application filed October 28, 3318.

To all whom it may concern:

Be it known that 1, AUGUST ZKAZEHBii-XIER, engineer, a subject of the German Emperor, residing at and whose ost-ollice address is Stuttgart,'Miihlrain 9/ Germany, have invented certain new and useful Improvements in Automatic Electric Regulating Devices; and I do hereby declare the following to be a full, clear, and exact description of invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In known regulators in which the alterable resistance of the exciting circuit of electric machines (dynamos, motors) con sists of a pile of conducting bodies, such as carbon granules for example, which are subjected to differences of mechanical pressure, ilectromagnets have hitherto been employed for moving the plate that bears upon the pile, the armatures of which are separated from the active pole surface of the magnet by an air gap of differing magnitude. V 1th such magnets, the more the armature is attracted, 1; 1e smaller the air gap becomes, and thus the attractive force increases, in accordance with the known law, in a degree inversely proportional to the square of the distance. But the regulating process requires that the attractive force of the armature shall be as nearly as possible propcrtional only to the electric excitation or energization of the magnet and practically independent of other influences, for then only will the pressure exerted upon the pile of g 'anules alter in strict accordance with the fluctuations of the magnitude (potential, current) that is to be regulated. New differenoes of the air gap between the armature and the poleof the electromagnet will,with one and the same degree of change in the value of the electric excitation, gdve rise Speciflcation of Letters Patent.

tance of the armature from its pole differs, the sensitiveness of the regulator will also differ, and the regulating operation is unfavorably affected.

The condition that the pressure exerted upon the pile of granules shall, as far, as possible, depend only on the changes of the magnitude to be regulated, will thus be fuliilled by the electromagnets hitherto employed, only if the surface of the pile of granules is always at oneand the same distance from the pole surface of the magnet; for since the pressure plate is rigidly coupled with the armature, the air gap between the armature and the pole surface can be kept constant in a stable condition of the regulator only if the said distance between the granules and the pole surface remains the same. .Butthis demand is difficult to fulfil, because, in consequence of the vibration of the vehicle in which the machinenitude to be regulated, the granules tend.

to shift their positions and to pile up on one side only. Attem )ts have been made to remove this drawbacl: by subdividing the pile of granules orby similar devices, but a disadvantage of these arrangements is that, in addition to imperfect action, they render the regulator more complicated. The object of this invention is to remove the d awbacks herein before described.

This object is accomplished by arranging the pile of granules with respect to the plate by which they are compressed, in such manner that the plate (in spite of a comparatively large distance of movement, within the known limits between which the core of the solenoid exerts a practically constant attractive force upon the plate) may assume any position with respect to the-pile, without the attractive force of the relay, presuming that its energization remains constant, being changed, so that a change of resistance of the pile of granules is produced which is as nearly as possible magnitude to be regulated.

It is known that. the forces of attraction exerted by an electromagnet or solenoid on Patented Feb. 24, 1&241.

proportional to the i corresponding distances between the center of the solenoid and the core, these distancesv being marked along the ahsciss:3earc repre sented by a curve which ascends from zero to a maximum value and then descends again to zero. This curve has a crest portion, corresponding to a considerable portion of the abscissee, and representing forces of attraction of equal values. Thus throughout a considerable change of the distance between the bearing surface of the pressure member and the fixed solenoid, the attractive force remains practically constant, and no matter whether the pressure member dipping into the pile of granules is located near down to the bottom oi? thegranlule chamber or up on a point of a stacked up pile of granules, the attraction. of the armature and hence the pressure exerted by the said memher is, as nearly as necessary for practical purposes, proportibnal to the degree of magnetization of the solenoid. By the arrangement according; to the invention the pile of granules, assembles around'and beneath the pressure plate, so that the pressure member is in a sense supported by the pile oft granules, or so to speak, floats in the pile. The

pressure plate can be made to assist this action if its dimensions taper away in the direction receding from its-pressing surface,

a pyramid or core form of plate being this specially suitablefor the desired end. By this means, not only an easy trickling down of the granules and a reduction of their friction against the plate is insured, but the additional advantage is obtained that, even when no pressure whatever is exerted by the plate and as long as it is not fully separated from the granules, the electrical resistance of the pile can never become infinitely great, because, on account of the tapering form, portions of the pile of miles always remain in contdct with n.- nle surfaces of the plate, so that the circuit through the pileof granules is never entirely interrupted. This circumstance contributes considerably toward the prevention of spasmodic regulating action.

The invention is illustrated in the accompanying drawing in which Figure l is a known graphical representation of the forces of attraction oia solenoid.

Fig. 2 is a diagrammatic sectional view of a smlenoid and its connections with a dynamo and Fig.6 shows a specific form of magnetic casing enveloping the solenoid.

In Fig. 1 the abscissa 0: represent the distances of the center of gravity of the core of the solenoid from the magnetic center of the solenoid. T he ordinates indicate cor responding attractive forces of the solenoid. In the magnetic center M of the solenoid the force of attraction is zero, and it may be assumed that this force drops again to zero meters when the core has traveled a consideriihle distance away from the solenoid into the position N. Now if the core or armature moves between the points M and N the force of attraction increases as shown by the curve K, until it reaches a maximum and then it drops gradually till itagain reaches the .zero point. it is known that the maximum force is exerted when the armature is approximately in the position shown in Fig. 2. It will be seen that the crest portion of the curve is very fiat, so that the maximum values of the forces of attraction change very little within the limits of movement of the armature, which are described by the distance a This section 0: is therefore used for the travel of the armature. If the magnetization of the coil of the electro-magnet alters, the force of attraction will also change and, if graphically shown, it will, for eg iample, describe the curves K K,, i, but the crest portion of the curve will always be nearly flat, so that the section a will appear as suitable for the various positions of travel of the armature. s

The invention is exemplified in Fig. 2, in which a case is shown of a dynamo driven at varying speeds, and in which the potential oi" the machine is to be regulated so as to be maintained constant; The shunt field winding 5 is therefore connccted to the pressure plate 0. This plate is pressed by a spring (5, that is held by the support 70, against the pile of granules e, which is inclosed in the chamber The bottom of thechamber f is connects by the wire g'to a terminal of the dynamo, the other terminal of the dynamo being connected to the other end of the field winding. The voltage at the machine terminals is applied to, the winding of the solenoid. The pressure plate a is coupled to the core or armature z' by a, rod of such length that the core lies in the zone of the maximum of attractive force 01 the solenoid. When the pressure plate 0 moves up ward the granules trickle or roll down the cone surface of the plate, so that a pileof suliicient thickness will always accumulate on the bottom of the chamber.

The eneral functions of such regulators are so ciently known and. need not be described 'lierein. If the granules pile up in 'any position whatever, the armature will In the"'elaims"the"term' electric "magnitude will vbe used tdtlenote .potential, voltage, current strength etc.

I claim; r

1. An automatic regulator for regulating an electric Inagnitudedepending on an electric machine, comprising a relay with a coil to which said electric magnitude is applied, an alterable resistance consisting of a pile of conducting bodies, and a pressure plate 0 eratively connected to the armature of sai re-.

lay and adapted to press uponsaid ile, said pressure plate tapering upwardly m the pressin surface so as to allow sald conductin 105 81 portions.

2. An automatic regulator for regulating an electric magnitude depending on an electric machine comprising a relay with a 0011 to whichrthe sai plied, an alterable resistance consisting of a surface of the pressure ies'to slide from its upper to the electric magnitude is applate and the said armatuze by w ich the 4 armature is always kept in a zone of approximately constant attractive force, so as to produce alterations of the said resistance practically proportional to the electric magnitude applied to the said coil, the pressure plate tapering upward from the pressing late so as to allow the said granules to sli e from its'upper to its lower portions.

In testimony whereof I aflix my signature in presence of two witnesses. I

I AUGUST KAZENMAIER.

Witnesses: 4

JOHANNES Ennnnme, ADOLF Lnnmm'rz.

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