US1124630A - Dynamo-electric machine. - Google Patents

Description

H. LIPPELT.

DYNAMO ELECTRIC MACHINE.

APPLlGATIoN FILED omas, 1909.

Patented Jan. 12, 1915.

5 SHEETS-SHEET 1.

w 5 w M 3 I.. w MUI Mln .Mv Ilumwlllku n. n .un n x Wl n .HT .U n 5 .a -m 3 l Q @9i/humaan THE NoRRls PETERS C0.. PHOTO-LITHO WASHrNn'r'nNV D. cA

H. LIPPELT.

DYNAMO ELECTRIC MACHINE.

APPLIOATIOH FILED 00T.13, 1909.

1,124,630. Patented Ja11.12,1915.

5 SHEETS-SHEET 2.

fly/JMW] WMMV THE MORRIS PETERS Co.. PHUTCI-LITHO., WASHINGTON, Dv Cv H. LIPPELT.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED OGT.13, 1909. 1,124,630. Patented Jan.12,1915.

5 SHEETSSHEET 3.

@13 abbo/(Meg 62X) ift/mmf JM THE NORRIS PETERS CO.. PHOTO-LITHQ, WASHINGIUN. n. c.

H. LIPPELT.

DYNAMO BLEGTRIG MACHINE.

APPLICATION FILED 0GT.-13, 1909. 1,124,630.

Patented J an. 12, 1915.

5 SHEETS-SHEET 4.

THE MORRIS PETERS Co., PHDTGLITHO WASHIN'G TON, D C.

H. LIPPELT.

DYNAMC ELECTRIC MACHINE.

APPLICATION FILED 00T.13, 1909.

1,124,630. Patented Jan. 12, 1915.

5 SHEETS-SHEET 6.

THE MORRIS PETERS CD.. PHOTO-LITHO.. WASH'NOTON, D. c

STATES PATENT OFFICE.

HANS LIPPELT, OF NEW YORK, N. Y.

DYNAMIC-ELECTRIC MACHINE.

Application led October 13, 1909.

To all whom t may concern Be it known that I, HANS LIPPELT, a citizen of the German Empire, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful .improvements in Dynamo-Electric Machines, of which the following` is a speciiication.

lily invention relates to dynamo-electric machines; and consists in improvements in the machines and described in my prior U. S. Patents Nos. 756,793 and 919,60i. ln these patents l have described a dynamo electric machine having an armature of the open-coil type with commutator and brushes to maintain each armature winding in circuit while cutting the flux of the field poles, and in which the iield is arranged to induce a substantially uniform voltage in the armature conductors as they pass the field poles, both under load and at no load. An attempt is made, also to provide a sparkless commutation.

The present invention relates to improvements in such machines, and particularly to means for producing a more effective commutation, sparking being entirely obviated at all loads.

The nature of my invention will be best understood when described in connection with the accompanying drawings, in whichH Figure l shows diagrammatically an end view of the machine designed in accordance with my aforesaid invention, both armature and field being developed along a straight line. Fig. 2 shows a diagrammatic plan view of the armature, which as well as the windings and the commutator are developed on av plane surface. Figs. 3 to 6 are explanatory diagrams. Fig. 7 is a diagram of the induced voltages in the armature conductors of a generator, and Fig. 8 is a diagram of the induced voltages in the armature conductors of a motor. Fig. 9 is an explanatory diagram of the electrical changes occurring during the starting of a motor. 10 is a plan View of the armature of a motor constructed according to the present invention and developed on a plane surface. Fig. ll is a diagrammatic, fragmentary view illustrating the method and means of Specification of Letters Patent.

Patented Jan. 12, 1915.

serial NQ. 522,422.

connection between the armature circuit, commutator and terminals of the new machine. F ig. 12 shows a diagrammatic plan view of the armature, the winding, the commutator and the accessories of the improved machine developed on a plane surface. Figs. 13 to 15 show diagrammatically end views, developed along a straight line, of various main and auxiliary fields that may be employed in my improved machine. Fig. 16 is a longitudinal section of a machine constructed according to the present invention, and which may be run either as a dynamo or as a motor; and Fig. 17 is a similar view of a dynamotor.

Similar characters of reference designate corresponding parts throughout the several views.

To a better understanding of the present invention a brief description of the operation of the machines set forth in the aforesaid patents will be given, reference being had to Figs. 1 to 3 of the drawings. 19 designates an armature, considered stationary; and 20 a rotating field, the poles N and S of same being numbered 21 to 28. 21 to 26 are the main field poles and are unevenly spaced, the center lines according to an equal spacing being drawn to show the uneven pole pitch. The poles 27 and 28 are auxiliary poles inserted into the spaces left by the main poles, 27 being bifurcated but in its action may be considered as a single pole. The machine itself is to be considered as a six pole machine. The magnetizing winding 29 and the direction of current in the same is shown in the conventional manner, and the winding may be series, shunt or both. In addition to this winding 29, the auxiliary poles as well as such main poles which are displaced from their normal position, because of the uneven pole-pitch, are further provided with an auxiliary winding 30. It will be noted from the direction of current set forth that this auxiliary magnetization increases the main magnetization of certain of these poles and diminishes that of others. As more fully set forth in the aforesaid patents, the purpose of this arrangement is to neutralize the effect of the armature reaction and to produce a field-that is to say an E. M. F. curve whichiunderall loads is for the greater part horizontal (see E0, Fig. 3). The'armature 19, plan of which is shown in Fig. 2, is, for the sake of example, provided with four windings which are completed through brushes 35 and commutator 36 to four armature circuits 31-31, 32-32, 33-33, and 34-34- The winding is shown in Fig. 2 and resembles an open, multipliase winding, whose 3600 Wmdmg plJUCh*the number of poles' or a multiple of the same. In case of an even multiple, the ends of such conductors as are projecting from opposite ends of the armature core should be connected; and the end connections should run along a noninductive path. Special conditions, however, may require special end connections. By means of the rotating field 20, alternate electro-motive forces are induced in the armature windings, and in such a manner that always in at least three armature windings the same or nearly the ysame electro-motive forces exist.` The armature circuits thus energized are periodically connected in parallel through brushes 35 and a commutator 3G, Fig. 2, the current 'being delivered to the terminals 37 and 38 of the machine through suitable collector rings 39 and 40. The direction of the current in the armature circuits is indicated in the conventional inanner, Fig. l. The commutator 36 consists, for the six pole machine 'under consideration, of six segments 41, 42, 43, 44, 45, and 46 arranged in two rows 'of three segments each, the segments 41, 42 and 43 being negative and the remaining segments 44, 45 and 46 positive. The segments of :same polarity are connected to each other and withv corresponding collector rings 39 and 40. The position of the brushes is arranged to correspond with the position of the windings, in such a manner, that only when a winding is effectively vitalized through the induction of a field pole the respective brushes slide on a commutator segment. The armature circuits deliver power only so long as they are connected with the commutator segments, and thereby with the line. lIn the case of a dynamo, current is delivered from the collector rings; and in the case of a motor, it is delivered thereto. l

The electrical changes occurring within the armature circuits, in the case of a dyname, may be studied and discussed in connection with the explanatory diagram shown in Fig. 3, the arrow designating the relative motion of the armature with respect to the field magnets.` E Eo designates one-half of a waveof electro-motive force, P the constant terminal voltage,`I the current strength witha Ymaximum value Io, and r the resistance (assumed constant) of an armature-Circuit. betweenthe .noi-nts at .which it is connected in parallel with the other armature circuits. Ir represents then the ohmic drop in the armature circuit, and the curve I for the current is made to coincide therewith by assuming the proper scale. Beginning at the left side of the diagram, the E. M. F. existing in the armature circuit is zero, and at the position Q it has risen to the terminal voltage P. At about this time the brushes 35 make contact with the proper commutator segments of commutator 36 and the armature circuit is placed in action. Because of the further increase in the E. M. F. to the value of E0, a gradually increasing current I is developed.k In consequence of the self-induction of the armature circuit this current does not rise in a straight line but approaches an asymptote, which asymptote has the same inclination to the zero line as the line E. After the E. M. F. has attained its maximum value E0, the current curve I reverses its direction of curvature and attains after some delay its maximum value I0. At the points B, the E. M. F. and the current begin to decrease again, the E. M. F., however, more rapidly than the current which is again delayed owing to self-induction. At D, the E. M. F. has fallen to a value equal to the terminal voltage P, the difference being therefore zero. The current, however, has still an appreciable value which becomes Zero only at F. If the armature circuit be now switched out no sparking will occur since the current therein is at this instant equal to zero. As is apparent from the current curve, the current in the vicinity of its zero lvalue varies rapidly, and in consequence of which a faulty brush adjustment even to a comparatively small degree renders a spark unavoidable. Should the disconnection occur too late, a powerful spark is developed which strongly affects the brushes. A premature disconnection, also, causes the development of a spark, which, however, is soon extinguished and only slightly affects the brushes. This sparking, however, indicates a technical imperfection, and it is one of the objects of the present invention to improve such machines in this respect, obviating the sparking entirely. Other means having the same end in view are known but are based on a transformer action. Such means, however, are unsatisfactory in that they operate properly only at a particular speed of the machine and which speed cannot be high because, in consequence of the magnetic inertia of the transformer, the said transformer is not capable of responding to the numerous switching operations of short duration of the commutator. My invention consists essentially in employing means which will not possess these disadvantages, and -which will operatev without-fail at allspeeds 'ofthe machine. Such means are found in the electrical Condenser which is connected with an armature circuit shortly before the same is cut out or in. In going in, the circuit will thereby be precharged with current. For this purpose condensers 49 and 50 are provided and which are cut into the two branches 31 and 31', etc., of the armature circuits as follows-reference being had to Figs. 11 and 12. I also provide auxiliary commutator segments 51, 52, 53, 54, 55 and 56 which are comparatively narrow and are insulated from the corresponding main commutator segments 41, 42, 43, 44, 45 and 46 by small strips of insulating material, the segments 51, 52, and 53 being at the right of the corresponding negative segments 41, 42, and 43, while the segments 54, 55 and 56 are at the left of the corresponding positive segments 44, 45 and 46. For high voltages it is advisable to arrange all positive segments on one ring and all negative segments on another ring, as shown, in order to secure good insulation. The segments 51, 52 and 53 which are of the same polarityT (negative) are connected to one another, and likewise the positive segments 54, 55 and 56. The segments thus connected are then connected through suitable resistances 57 and 58 respectively to one side of the condensers 49 and 50 respectively. The other sides of the condensers are connected respectively to the terminals 37 and 38.

l'n addition to the armature circuits 31-31, 32h32', 33 33, and 34--34 which are connected through the brushes with the commutator 36, shunts 61-61, 62-62, 63?-63, and 64-64 may be provided. These shunts are then connected respectively to the corresponding branches of said armature circuits and are arranged to be connected to the commutator 36 through suit-able brushes 65, which as well as the brushes are of sufficient width to span the insulating spaces between main and auxiliar)v segments of the commutator. Resistances 66-66, 6T-67, 68-68, and 69-69 are inserted in the corresponding shunts. The arrangement of the brushes is such that for each end of each armature circuit a set of four brushes is provided, there being two adjacent brushes of slight angular difference in position for each polarity see Fig. 11), and the connections for each set of brushes being crosswise. Through the arrangement above set forth, the connection of each end of each armature circuit to the con'nnutator is in one case direct, and in the other through a resistance. The brushes 65 are in advance of the brushes 35 going in the direction from an auxiliary commutator segment to a main connnutator segment. 1n the position shown (Fig. 11) the current, for example, will How from one end 31 of the armature winding 31-31, through the shunt 61 and its resistance 66 and the brush 65, to the commutator segment 44, and then to the terminal 38. rllhe branch 31 also connects through brush with the auxiliary segment 54, and thence through the resistance 58 and condenser 50 to the terminal 33 The resistances 66 and are thus connected in parallel. The return circuit is from the terminal 37 directly to the commutator segment 41 and through brush to the other branch 31 of the armature circuit 31-31. No appreciable current will iiov.' through the resistance 66 of the shunt 61 as the conductor in parallel therewith has very little resistance'. 1f the brushes are now assumed displaced somewhat toward ing, and `back through the resistance 66 of shunt 61, through brush 65 to auxiliary segment the resistance 58, condenser 50 to the terminal rhe armature circuit 31-31, the condenser 50, and the resistances 53 and 66 are thus connected in series. lf the brushes be moved still farther in the same direction, the armature circuit 31-31 is completely disconnected from the commutator and thereby from the line. Had the brushes been shifted in the opposite direction and had the connections made at the other ends of the cominutator segments been investigated, it would have been found that lirst resistance 57 and condenser 49 would have been connected in parallel with resistance 66. Further displacement would have placed the armature circuit, shortly before the disconnection of the same from the comniutator 36, in series with the condenser 49 and the resistances 5T and 66. The arrangement affords, therefore, the same succession of connect-ions for both directions of revolution. F or such armature windings are going into circuit, the succession of connections is of course the reverse, that is to sav the series connection is first made of the resistances 57 or and 66 or 66 and the ri-ondensers 4i? or 50, and then the parallel connection of resistance 5T and condenser il) with resistance 66: or, resistance 5S and condenser 56, with resistance 66, and finally tbe direct connection of armature circuit through the main segments of the commutator to the terminals (omitting the said resistances). The increase of resistance, therefore, does not take place suddenly, but sten by step (gradually).

The electrical changes occurring in the armature circuits under the conditions above set forthv are indicated for a dynamo in Fig. 4. For the sake of simplicity it is at present to be assumed that the resistances 57, 58 are zero and the entire branches 61, 61 are omitted; and their purpose will hereinafter be set forth. Referring to Figs. 4 and 11, let it be now assumed that the iield and the commutator, (Fig. 1l) rotate to the left, and that the armature and brushes are stationary. This condition characterizes circuit 31-31 as an ingoing circuit. soon as the segment 54 has moved under a brush 35, the position of armature winding 31-31, with reference to the field, corresponds to the position Q, Fig. 4. One branch of the circuit 31-31 will be connected with the segment 54 and in series with the condenser 50, while the other is connected through the segment 4l directly to the terminal 37. The current will therefore rise rapidly because of the capacity of the condenser 50. The ohmic drop curve Ir (representing also current I) is shown between the lines Q and S, the current striving asymptotically to a constant positive limit. As soon as the E. M. F. attains the value E0 and remains constant, the curve I changes,'striving very rapidly but asymptotically to a zero value. It is therefore necessary to disconnect the armature circuit 31-31 from the condenserI 50 as soon as, or shortly before, the E. M. F. attains its maximum value E0. The armature circuit is then already energized and may immediately begin its work in full measure, effecting thereby a greater output than un der the conditions set forth in Fig. 3. At the position B, the current I begins to drop, as shown, between B and I) in the same manner as the similar curve shown in Fig. 3. At the position D, Fig. 4, the condenser 49 is to be introduced, that is, for example, before the E. M. F. curve E had dropped to the value P. The form of the curve I will therefore change, striving rapidly and asymptotically to a constant negative limit. This is a decided advantage over the condition set forth in Fig. 3 wherein the current continually decreases (in an algebraic sense). For the sake of completeness the tension at the condenser is shown by the curve e, Fig. 4. The disconnection of the armature circuit should again be made, as in the case set forth in Fig. 3, just before the position F where the current becomes zero. The above set forth negative limit of the current is proportional to the trigonometric tangent of the angle of inclination of the line E. If now E, during this period of switching out, be maintained substantially constant (horizontal), Fig. 5, the negative limit of the current thereby becomes zero. In other words, the current I is forced to a rapid striving toward zero as its limiting value. ,Y It -is not necessary, however, that for this purpose the said horizontal portion of said machine.

of the curve E should coincide with the line P. Since the current comparatively long before reaching F attains a value which practically equals zero, there remains a large margin for the accomplishment of discone nection, that is to say, an exact setting of the brushes is not necessary. Attention is particularly directed to the fact that with the aforesaid arrangement, the potential e of the condenser approaches a constant final limit, while the current approaches zero.

It is thereby immaterial whether the horizontal value of E (Fig. 5) is greater, equal to, or smaller than the value of P. Thus, the operation is independent of E-P. Since E and, with dynamos, P is dependent upon the speed of the machine, the commutation is also independent of the speed Vith other arrangements in which a transformer is utilized instead of the condenser, the potential due to self-induction would become zero, but the current would approach a constant value. This latter would only then become zero when the horizontal portion of E would coincide exactly with the terminal voltage P, (Fi-P20) which is a difiicult condition to obtain with variable load.

In employing a condenser as above described, there is only one, easily fulfilled requirement. If, as above, 7' is the resistance in ohms in the armature circuit, L the. @ifeative coefcient of self-induction (difference between its own self-induction and the mutual induction of the other circuits) in henries, and C the capacity of the condenser in farads then- In order that the condenser be not required to have too high a capacity, the resistance i' of the armature circuit must be suiiiciently increased during the switching period. For this purpose the above described resistances 57, 5S and 66', 66, etc., are provided and are arranged, as explained, to be introduced step by step into the armature circuit before and simultaneously with the introduction of the condenser. The arrangement is such, also, that the condenser during the step by step introduction of the resistance prevents the formation of a spark, and likewise during the step by step disconnection of the resistance at the beginning of the working period of the armature circuit. Brush 35 should then run off segment 54 before brush 65 runs onto segment 54, Fig. 11, or segment 56, Fig. l2, and the resistance 66 only will be in series with armature winding 3l-31. At the next instant brush'65 will Contact both segments 54 and 44, Fig. l1, or 56 and 46,-'Figf12 '-(thus also discharging condenser` from 'previous charge) and will then contact 54 or 56 only.

rIhe amount of resistance for the three stages is then as follows: position shown 66 in parallel with 58 and 50 (less ohms than 66) 35 off 5-1; (66 alone); 65 on 54 or 456-66 and 58 in series (more ohms than 66). To determine these values of resistance it is to be noted that, although the actual resistance of the condenser is infinite, yet the same acts as a short circuit when not charged (resistance Zero) hence, only the values of resistances 57 and 58 are to be considered. After the condenser is fully charged it sets up a counter voltage acting as an infinite resistance and permitting no current to flow. The introduction of the resistance, also has a favorable action in reducing the strength of the current. The diagrams, Figs. el, and 6, retain their significance for the varying resistances, but the scale for the current is to be changed to correspond to the changed resistance. In many cases it is possible to do without the resistances 57, 58, for example, if the resistances 66, 66 suffice. If the above conditiona T C be not fulfilled, the electric current will be subject to damped oscillations.

Fig. 6 shows the electrical conditions for a motor, and in which, as is well known, the E. M. F. of the armature circuit is less than the terminal voltage. The current has naturally the opposite direction to that existing in a dynamo, as is shown in Fig. 8.

For the production of E. M. F. curves, which after a short slope again follow a definite horizontal course, flat curves EE, as shown in Figs. 8 and 4i are presumed. Their production and maintenance under all loads has been previously set forth. Through additional induction, these fiat curves are altered at the ends in the desired manner. Fig. 7 shows the original flat curve Fm for a dynamo, the additional curves of induction z and the resulting curve EE0. Since the machines in general are to be adapted to both directions of revolution, a curve of induction is provided also at the left side of the curve. For the relative motion of the armature with respect to the field as indicated by the arrow, this is the beginning of the working period; and the supplementary induction strengthens at this place the original E. M. F. while at the other end it weakens the same. lVith a change of direction of revolution, the effect is reversed automatically. Fig. 8 shows the electrical condition for an electric motor. In Figs. 7 and 8, E0 and P are represented by the distance between positive and negative values. It is, however, sufficient to refer to the half-wave only, if the scale of ordinates be reduced one-half (twice the number of division lines for the same length).

In the case where the machine is run as a motor, at the beginning of the starting period the inductive effect of the eld is zero, the E. M. F. is Zero, and the terminal voltage is equal to the drop in voltage, reference being had to Fig. 9. In switching in a circuit between a main segment of one polarity and an auxiliary segment of opposite polarity, the current will rapidly rise on account of the condenser and then again diminish. Yet, even at moderate speed and with sufiiciently high resistances (57, 58 and 86, 86, etc., Figs. ll and l2), the position S which designates the passing over to the main segv ment adjacent to the auxiliary segment, will be reached at such time that the current is impeded in its complete decrease and instead is sustained now from the driving source of current charging over the main segments. A premature decrease of current, however, would not signify anything detrimental. After the connection to the main segments, the armature circuit will do constant work until it has passed the position B and has reached the position D. At this moment the condenser is connected into series with the same and thereupon the current in the armature circuit is forced to a tendency to rapidly attain the Zero value, so that a sparkless disconnection may take place before the position F is reached.

In order to provide sufficient resistance in the armature circuit for the support of the commutation it is advisable to locate the starting resistance, not outside of the armature, but within the armature winding as shown in Fig. l0. Adjustable starting resistances 7l, 72, 73 and 7i are introduced into the corresponding armature winding sii-ar, :a2-3e@ 33 33', en ar, as Shown in Fig. 10 and are jointly and gradually cut out of circuit in the same degree as the speed of the motor increases, until they are finally completely cut. out. Of course, this arrangement is suitable, also, for the control of the speed.

It is known that a condenser requires time to absorb electricity, even though it be extremely short, and that this time is lengthened by the introduction of resistance into the circuit. Should the machine run slowly, or at moderate speed, the condenser during the switching out period even with the large resistance 7 of the armature circuit will sufficiently quickly render the current zero. At high speed, however, it is advisable to assist the condenser by means of additional induction. The available time for extinguishing the current decreases at such increased speed, but the induction increases correspondingly and thus works in harmony. lilith the switching in of an armature circuit the additional induction operates in a similar manner to accelerate the current development. In a similar manner it may be shown that the additional induction, also with'dynamos, supports the commutation. As a more satisfactory means for providing such supplementary induction and to obtain the desired E. M. F. curves I have designed the means shown in Figs. 12 to 16, Fig. 16 representing upper part of a complete machine. The armature 19 is stationary; and the field 20 rotating, as in the device shown in Figs. 1 and 2. In addition to the said field and'armature, a small auxiliary armature S0 and an auxiliary field 81 are provided. The armature is constructed in the same manner and wound similarly to the armature 19 only its axial length is considerably less, and its windings 76-76, 77- 77', f8-78, 79-79 are connected in series with the circuits 31-31, 32-32, 33-33r and 311-34 respectively (Fig. 12). While the main armature 19 is absolutely stationary, the auxiliary armature 80 is circularly adjustable, Fig. 16, as by sliding in guides 82, and locked by suitable bolts 83. The setting is done once for all, the adjustment being such that the additional inductions to be provided are introduced at the desired time, for example as set forth in Figs. 7 and 8. The connections from armature to terminals are the same as have already been explained, but because of better design the separation of the adjacent brushes is increased angularly by double the normal pole-pitch, Fig. 12, or a multiple of the double pole-pitch. In other words the displacement has been made to the next segment of same polarity. Within the main armature 19 rotates the magnetic field 20 Figs. 13, 14 and 15 as in the machine illustrated in Figs. 1 and 2. The pole distribution of the main field, however, need not be uneven as set forth in Figs. 13 and 14, but the poles of the main field may be uniformly distributed as in Fig. 15, the compensation for armature reaction and the lvarious additional inductions being provided entirely by the auxiliary field 81whose poles are arranged accordingly. As shown in Figs. 13 and 14, the compensation for armature reaction is provided practically entirely by the main field, the supplementary inductions being furnished by the auxiliary field. The auxiliary field 81 is much smaller than the main field 20 and rotates within the auxiliary armature 80, and should be designed to take care of the armature reaction and supplementary inductions not furnished by the main eld. The pole-pitch, the size of the poles, and the magnetic polarities are so chosen that the supplementary induction provides the desired changes, satisfying, for example curve z, Figs. 7 and 8. Exciting windings 8S are provided for these poles, but the current therein need not necessarily be proportional to the armature current. However, in many cases it will be convenient to utilize the armature current for the excitation so that a reversal of the direction of revolution of the armature will cause the polarities of the field to be reversed. Instead of making the auxiliary armature 80, Fig. 16, adjustable as above set forth, the magnetic field 31 may be arranged to be adjusted. This arrangement will be especially desirable when the armature rotates and the field is stationary. In a machine thus constructed with auxiliary armature and field, the capacity of the auxiliary armature and field need be hardly more than a few per cent. of the entire capacity of the said machine. In thus employing auxiliary armature and auxiliary field, a decided advantage is obtained in that the same may be controlled independently of the main field and of the main armature, thus affording for the purpose of regulation the entire ranges of magnetic strength of said field magnets. If the regulation were to take place in the main field magnets, only a fraction of the latters magnetic strength would be available and the adjustment of exciting current would therefore have to be more delicate.

In the case of a dynamotor Fig. 17, in addition to the main armature provided with the dynamo winding and a motor winding 91, two auxiliary armatures 93 and 94-1 and two corresponding auxiliary fields 95 and 96 are required. The auxiliary system 93, 95 serves for the dynamo, and the system 94, 96 for the motor. Corresponding sets of accessories and connections to the terminals are of course necessary, the designation for the dynamo side being the same as used throughout the drawing, while those of the motor sides are primed.

In some cases it is possible to dispense with one or the other of the means hereinbefore set forth. For example, since the maximum value E0 is substantially uniform (horizontal) it is possible in certain cases to carry out the disconnection of the armature circuits without first diminishing the maximum value. The auxiliary armature and its field will then become unnecessary and may be dispensed with. It will also be apparent that the step by step increase or decrease of the E. M. F. as shown in Figs. 7 and 8 may be made to take place gradually, care being taken, only, that it remains constant during the cutting out of the armature circuit. The extinction of the current may be accomplished solely by the introduction of resistance, by means of supplementary induction, or both.

It is understood that the invention is applicable to multi-polar or bi-polar machines. I also do not wish to restrict myself to the specific manner shown of connecting the armature windings, resistances and condensers with the terminals, except as limited by the appended claims.

In conclusion, it is to be noted that the desired results herein set forth are attained by means of a process which consists in producing within the armature windings electro-dynamic cycles. Each cycle consists iin-(ll a state of idleness during which .voltage exists but no power' is generated in,

, a part-p 2 receiver (condenser), and the remainder transformed into heat (Pr) and dissipated. (Q to S, Fig. 4). The duration of this period may be aifected strongly by the gradient of the E. M. F. Anch-(3) the windings enter upon a state of useful power development. ln general, all of this power is discharged into the line circuit, with the exception of the heat loss. (S to B, Fig. Finally, (l)-a state of decline is reached, during which power is still being produced. At the beginning of this period this power and a part of the magnetic energy stored up during the second period above set forth, is discharged to the line. (B to D, Figs. 4 and 5). rllhereafter, the power further producedl and the remainder of the stored up energy are diverted into a suitable receiver, such as a condenser, D to F, Fig. l). rlhe power and the 'magnetic energy stored up in the windings may be rapidly consumed by maintaining a special gradient of the F. M. F., i'iZ.-i'ececli1ig Fi. M. F. State (l) will soon be reached, and the cycle com` pleted. During the whole electro-dynamic cycle the inducing magnetic linx, especially also its gradient and the so-called constants of the circuit are regulated to best suit the working conditions, as for instance, varia tions of power and energy may be accelerated in order to reach limit values of current by. maintaining magnetic flux and its induced E. M. F. at special gradient. By constants of the circuit is ordinarily understood the values of resistance, capacity, conductance, inductance, time constant (in exponential function )is discharged into a eg), etc. These constants might more properly be called the characteristics of the circuit, and changing the characteristic means-adding or taking away resistance, capacity, etc. It is obvious that the effect ot the change of some of the characteristics of the circuit may be obtained also by corresponding changes of the motive force (E. M. F.) through superposed inductions, viz: an addition of resistance may be taken care of by induction in a direction opposite to the flow of current.

I claim l. In a dynamo electric machine: the combination with a field, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits at predetermined periods.

2. In a dynamo electric machine: the combination with a field, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits shortly before the same are disconnected from the terminals of the machine.

ln a dynamo electric machine: the combination with a field, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of a condenser, and means to introduce the condenser into the armature circuits shortly before the same are disconnected from the terminals of the machine; and means to disconnect the condenser shortly after it is introduced into the armature circuits.

4. In a dynamo electric machine: the combination with a iield, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits shortly before the same are connected to and shortly before they are disconnected from the terminals of the machine; and means to disconnect a condenser shortly after it is introduced into the armature circuits.

5. In a dynamo electric machine: the combination w'th a iield, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits at predetermined periods; and one or more resistances, and means to introduce resistance into the armature circuits at predetermined periods.

6. n a dynamo electric machine: the combination with a iield, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits at predetermined periods; and one or more resistances, and means to introduce resistance in series with the armature circuits prior to a series introduction of the condenser.

7 In a dynamo electric machine: the combination with a field, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of one or more condensers, and one or more resistances; and means to first introduce resistance in series with the armature circuits, and then simultaneously introduce additional resistance and a condenser in series with said first resistance.

S. In a dynamo electric machine: the combination with a field, an armature having windings of the open-coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of one or more condensers, and one or more resistances; and means to gradually introduce resistance into the armature circuits at predetermined periods, and to introduce a condenser into the armature circuits at predetermined periods.

9. In a dynamo electric machine: the combination with a field, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of one or more condensers, and one or more resistances; and means to introduce resistance and a condenser simultaneously into circuit with an armature winding prior to cutting the whole into the line circuit and to disconneet the condenser and resistance at a predetermined instant, and, prior to cutting the said winding out of the line circuit, to introduce resistance in series with said armature winding and then additional resistance and a condenser in series with said resista-nce, and finally to open the connections made.

10. In an electric motor: the combination with a field, an armature having windings of the open-coil type, and a suitable commuA tator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of controlling resistance, and means to connect said resistance to the armature windings on the armature side of the commutator.

11. In an electric motor: the combination with a field, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; one or more condensers, and means to introduce a condenser into the armature circuits at predetermined periods;

ducing a magnetic field, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; `of one or more condensers, and means to introduce a' condenser into the armature circuits at predetermined periods; one or more resistances, and means to introduce resistance into the armature circuits at predetermined periods; and means to induce suitable, supplementary electro-motive forces in the armature circuits at predetermined periods.

13. In a dynamo electric machine: the combination with suitable means for producing al magnetic iield, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits at predetermined periods; one or more resistances, and means to introduce resistance into the armature circuits at predetermined periods; and adjustable means to induce suitable, supplementary electro-'motive forces in the armature circuits at predetermined periods.

14. In a dynamo electric machine: the

' combination with suitable means for producing a magnetic ield, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain each armature winding in circuit during predetermined periods; of one or more condensers, and means to introduce a condenser into the armature circuits at predetermined periods; one or more resistances, and means to introduce resistance into the armature circuits at predetermined periods; and suitable means for producing an auxiliary magnetic field, and an auxiliary armature having windings of the open coil type in series with the corresponding windings of the said main armature to superpose suitable electro-motiye forces upon the electrocombination with suitable means for producing a main magnetic field, a main armature and suitable windings, and a suitable commutator and brushes, ot an auxiliary armaand suitable windings for said auxilarmature, and suitable means for proan auxiliary magnetic ield having Aly spaced and unequally excited poles. Tn a dynamo electric machine: the combination with suitable means for producing a magnetic iield, ,an armature having wir li s the open coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers; and means to introduce a condenser into the armature circuits at predetermined periods; and means to maintain the electro-motive torce induced in the armature windings substantially uniform during the period of switching out of an a ri Aa ture circuit.

18. ln a dynamo electric machine: the combination with suitable means 'for producing a magnetic field, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers adapted to be introduced into the armature circuits, and means to induc suitable, supplementary electro-motive forces in the armature circuits at predetermined periods.

ln a dynamo electric machine: the com Jination with suitable means for producmagnetic field, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; of one or more condensers adapted to be introduced into the armature circuits, suitable means for producing an auxiliary magnetic field, and an auxiliary armature having windings oi' the open coil type in series with the corresponding windings of the said main armat to superpose suitable electro-motive Uure forces upon the electro-motive forces of the main armature windings.

20, ln a dynamo electric machine: the combination with suitable means for producing a magnetic field, an armature having iindings of the open coil type, a commutator having two rows ci segments, the one row being positive and the other negative, and suitable brushes to bear upon said segments; of one or more eondensers, and means to introduce a condenser into the armature circuits at predetermined periods.

2l. ln a dynamo electric machine: the combination with suitable means for producing a magnetic lield, an armature having windings oi the open coil type, a commutator having positive and negative main segments, auxiliary segments adjacent to said main segments, suitable brushes to bear upon said main and auxiliary segments, and intermediate connections; ot one or more condensers adapted to be introduced into the armature circuits at predetermined periods and to be discharged by the commutator brushes.

22. ln a dynamo electric machine: the combination with suitable means for producing a magnetic iield, an armature having windings of the open coil type, a commutator having positive and negative main segments; adapted to be connected to said armature windings; shunt circuits to parts of the armature circuits, resistance included in each of said shunt circuits, auxiliary segments adjacent to said main commutator segments, suitable brushes to bear upon said main and auxiliary segments, and intermediate connections; of one or more condensers adapted to be introduced into the armature circuits at predetermined periods and to be discharged by the commutator brushes.

Q3. In a dynamo electric machine: the combination with suitable means for producing a magnetic field, an armature havingv windings of the open coil type, a commutator having positive and negative main segments adapted to be connected to said armature windings, shunt circuits to parts of the armature circuits, resistance included in each ot said shunt circuits, auxiliary segments adjacent to said main commutator segments, suitable brushes to bear upon said main and auxiliary segments, and intermediate connections; of one or more condensers, adapted to be introduced into the armature circuits at predetermined periods and to be discharged by the commutator brushes; and means to induce suitable, supplementary electro-n'iotire forces in the armature circuits at predetermined periods.

24e. ln a dynamo electric machine: the combination with suitable means for producing a magnetic field, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during predetermined periods; ot one or more condensers and one or more resistances; and means to introduce resistance into outgoing armature circuits, and to shunt additional resistance and a condenser thereto, and shortly thereafter place the latter two in series with the former.

25. ln a dynamo electric machine: the combination with suitable means for producing a magnetic lield, an armature having windings of the open coil type, and a suitable commutator and brushes arranged to maintain the armature windings in circuit during` predetermined periods; ot' one or more condensers and one or more resistances; and means to introduce into ingoing New York and State of New York this 12 day of Get. A. D. 1909.

HANS LIPPELT.

armature circuits resistance and a condenser in series, and then shunt part of the resistance to the remainder of the resistance and to the condenser; and means to effect seid Connections in the reverse order for outgoing circuits.

Signed at New York in the county of Witnesses:

LAURA E. SMITH, FREDK F. SGHUETZ.

Copies o! this patent may be obtained for ve cents each, by addressing the Commissioner of Patents.

Washington, D. C.

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