US1801385A - Electrical apparatus for therapeutic and other purposes - Google Patents

Description

April 21, 1931 E. J. Rosa 1,801,385

ELECTRICAL APPARATUS FOR THERAPEUTIC AND OTRE R PURPOSES Filed Oct. 14, 1929 4 Sheets-Sheet 1 91 3 I; I H0 INVENTOR.

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E. J. Ross April 21, 1931 ELECTRICAL A PPARATUS FOR THERAPEUTIC AND OTHER PURBOSES- Filed Oct; 14. 1929 4 Sheets-Sheet 2 W =HW a IIIIII'IIIIIIII' IIIIIII'III )IIIII'IIIIIIIIIIIIII .77 Dunn,

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ATTORNEYS.

April 21, 1931. E. J. ROSE 1,301,385

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ELECTRICAL APPARATUS FOR THERAPEUTIC AND OTHER PURPOSES Filed Oct. 14, 1929 4 Sheets-Sheet 4 Pom Ciumcen Swift 3 DouN-E POL: nouuzfunon Rfll TO PATIENTS Swncu INVENTOR. f 090/1 Rose,

ATTORNEYS power currents or Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE EDGAR J. ROSE, OF L08 LNGELES, CALIFORNIA Application filed October 14, 1929. Serial No. 399,463.

This invention relates to improvements in electrical apparatus of the type in which mechanism is provided to modify a basic electrical current such as direct or alternating alvanic or faradic battery currents or ot er currents created by various mechanical and chemical means, and to create in a circuit delivered from this ap aratus sur es and slow waves of variable vo tages and orms which may be used preferabl as therapeutic agents, and may be time to correspond with the actions of the muscles, respiratory action of the human body or other animals. Basic or primary currents employed may be from selected sources or power currents or supplied by special generator or rectifier or battery of cells forming part of the apparatus or machine. These asic currents which are commercially known as direct currents, are referred to in medical practice as galvanic currents. Alternating currents are generally referred to in medical practice as rapid sinusoidal or rapid pulsatory currents. The basic currents may be made to surge in various shaped waves or their directions reversed at predetermined intervals by the mechanism herein described, and the various waves produced will have different characteristics. They may also be controlled by the apparatus as to voltage and amperage, and the direct or pulsatory currents may be modified or unmodified in form.

The apparatus is primarily designed for the production of currents to be used for therapeutic or medical purposes but it will also be understood that the modified currents produced thereby may be employed for other purposes, such as industrial, scientific or other commercial purposes within the scope of the invention as set forth.

An important object of this invention is to'provide for production of electrical current waves which may be made to correspond to the normal or abnormal actions of muscle and generally to produce electrical current waves of various forms or characteristics which are necessary or desirable for therapeutic and medical, as well as other scientific purposes.

Another object of the invention is to provide for production or modification of various forms of current waves without the use of cams, cones, or intermittent Geneva stop mechanism which have heretofore been used for that purpose and have been open to the objection of causing incessant trouble and requiring continual service for maintaining them in operative condition.

Another important object of the invention is to provide for elimination of oscillations when using the apparatus for production of rectified alternating electric currents. Other objects of the invention will appear hereinafter.

The accompanying drawings illustrate embodiments of my invention and referring thereto:

Fig. 1 is a front elevation of the apparatus.

Fig. 2 is a plan view of the apparatus with the cover broken away to show the various electrical devices mounted on the base thereof.

Fig. 3 is a rear elevation of the apparatus shown in Fig. 2.

Fig. 4 is a side elevation of the apparatus shown in Fig. 2, viewed from the left.

Fig. 5 is a rear elevation of the variable speed mechanism.

Fig. 6 is a side elevation of the switching means for changing from alternating to rectified current operation.

Figs. 6 and 6" are detail elevations of cam means for operating such switching means.

Fig. 7 is a section on line 77 in Fig. 6.

Fig.8 is a section on line 8-8 in Fig. 4.

Fig. 9 is a diagram of the circuit connections.

Fig. 10 is a series of diagrams of different wave forms which can be produced by the operation of the apparatus.

The apparatus is preferably mounted in a casing comprising a base 1 and a cover mounted on said base, a part of the electrical apparatus being mounted on the base and some of the electrical devices being preferably mounted on the cover as shown. I have shown as mounted on the base a transformer 4 for furnishing alternating current to the apparatus from a suitable supply line, rectifying means 5, electric swltchmg means 6 for changing from alternating to rectified current and vice versa, automatic current modifying means 7 and an electric motor 8 for operating said automatic current modifying means. The forward portion of the cover means, indicated at 2, is preferably secured in fixed position on the base 1 and various instrumentalities for control of the operation of the apparatus are preferably mounted thereon, the rear portion 3 of the cover member being removably mounted for access to the apparatus.

The switch means 6 may comprise a vertical plate 9 of insulating material mounted on the base 1, for example by bars 10 extending from a frame 11 secured to said base, and four rows or series of switch devices mounted on saidinsulating plate for changing the circuit connections so as to provide for production of either alternating or rectified current. One set of switch devices comprises movable members, indicated at 12, 13, 14 and 15 (see Fig. 6) which are respectively pivoted to the insulating plate 9, for example, one above another, in a vertical row and are connected by an insulating link or bar 16 so as to move in unison. Each of these movable switch members cooperates with fixed contacts as hereinafter described.

A lever 19 mounted to rock on a pivot 19 on a suitable support 20 carries at the outer end of one arm thereof a fork 22 which embraces a pin 23 on the bar 16 so that rocking movement of the lever 19 will move the bar 16 and cause operation of the switch members 12, et cetera, in one direction or the other. Such operation of the rocking lever 19 is effected by cam means (see Figs. 2, 6 and 7) engagmg a pin or roller 24 on one arm of lever 19, said cam means 25 being carried by a shaft 26 mounted in fixed hearings on frame 11. Shaft 26 is operated manually in any suitable manner, for example by means of a gear wheel 28 on said shaft 26 engaged by a gear wheel 29 on a shaft 30 which is mounted in bearings on frame 11. Said gear wheel 29 is also engaged bya pinion 31 on a shaft 32 which is mounted in hearings on frame 11 and extends through the front of the casing of the apparatus, being provided with manual operating means, such as a thumb nut or handle 33' (Figs. 1 and 2).

The cam means 25 may consist of a disc as shown provided with two notches 34 and 35 (see Fig. 6") and with inclined projections or shoulders 34, 34 and 35 35", at either side of the respective notches, adapted to engage the said pin 24 in the rotation of the said disc in one direction or the other so as to force the pin through one or the other of said notches in the disc and turn the lever 19 so as to raise or lower the switch members in connection therewith.

Fixed contacts are provided on insulating plate 9 for cooperation with the movable switch members 12, 13, etc., said contacts being numbered 36 to 42 inclusive.

Another set of switch members 44, 45 and 46 mounted on insulating plate 9 is adapted to cooperate with fixed contacts 47 to 52 inclusive on said insulating plate, said switch members 44, 45 and 46 connected to operate in unison by means of insulating bar 54 carrying a.

pin 55 which is engaged by a fork 56 on a lever 57 pivoted at 58 to a suitable support on the frame 11. A pin or roller 60 on one arm of said lever 57 is engaged by a cam means 61 so as to operate the several switches 44, 45 and 46, the cam means 25 and 61 both mounted on the operating shaft 26 but being arranged in different angular positions thereon so as to operate the respective sets of switches at different angular positions of the shaft. Cain means .61 may consist of adisc having a notch 62 (see Fig. 6) with inclined projections 62 and 62" at opposite sides thereof and adapted to engage the pin or roller 60 .to turn the. lever 51 one way or the other according to the direction of rotation of shaft 26.

I An indicating wheel or drum 64 (see Figs. 2, 3 and 4) is mounted to turn on a shaft 65 on the frame 11 and is operated by suitable means so as to rotate in correspondence with I the rotation of the operating shaft 32, for example, by means of a sprocket chain 66 engaging with sprocket wheels 67 and 68 respectively onthe shaft of said indicating wheel and on a shaft 7 0 mounted in hearings on the frame 11 and connected by gearing 71 and 72 with the shaft 26 aforesaid. Said drum 64 is provided with indicating marks 63 corresponding to the different forms of current to be produced and received through a right opening 81 in the casing means 2.

Means are provided for modifying the current under control of the same handle 33 which operates the switching means aforesaid. For this purpose the shaft 32 may be provided with a crank wheel 69 to which is pivoted at 73 a link member 74 having a pivotal connection 7 5 with the frame 74 of an electric motor 8 mounted to slide on guides 77 carried by the base 1 so that thesaid electric motor may be shifted longitudinally in either direction throughout a definite stroke on said guideways by operation of the handle 33 on sha ft32. A rotary member 78 is mounted to turn in bearing 7 8 on the frame and is connected by suitable speed reducing gearing to the shaft of the motor 8 so as to be rotated by said motor, said gearing being enclosed within the casing at 80 and forming a part of the motor equipment. Said rotary member is provided with a channel member 82extending diametrically with reference to the 'axis of rotation of said member 78 and on each side of such axis A shaft 84 mounted in fixed bearings 85 on the base 1 is provided with an arm 86 carrying a pin or roller 87 adapted to engage in the channel means 82 on the rotary member 78 so as to cause rotation of shaft 84 by rotation of the said rotary member, said means 82 and 87 constituting coupling means connecting members 78 and 84 in such manner as to effect variable speed rotation of the member 84 by constant speed rotation of member 78. A sprocket wheel 88 on shaft 84 is connected by a sprocket chain 89 to a sprocket wheel 90 on a shaft 91 mounted to turn in a frame 92 on the base 1 and forming a part of the current modifying mechanism 7 hereinafter described.

On the frame 92 of the current modifying mechanism is mounted by means of bars 94 an insulatin plate 95 on which is wound a resistance winding 96, this winding consisting of suitably insulated wire, such as enameled wire preferably of high resistant metal and of very small diameter so as to provide the necessary resistance in a single layer wound on the insulating plate 94 aforesaid. The insulation of such resistance wire is removed on the side toward the rotary contact means hereinafter described so as to provide for electrical contact between the resistance wire and movable contact members or brushes 98 and 99 of said rotary contact means which travel over said resistance winding.

The rotary contact or commutator means indicated at 100 consists of a disc carrying the brushes 98 and 99 which are insulated from said disc by means of bushings 101 and are connected respectively (as shown in Fig. 8) to two collector rings 102 and 103 mounted on and insulated from the disc 100. A split contact ring comprising two semicircular sections 104 and 105 is also mounted on and insulated from the disc 100, section 104 being connected to brush 99 (as shown in Fig. 8) and section 105 being without circuit connection. Brushes or contacts 106, 107 and 108 are mounted on and insulated from the frame 92, brushes 106 and 107 being adapted to cooperate respectively with the contact rings 102 and 103 and brush 108 belng adapted to contact with the split contact ring sections 104 and 105.

Means may also be rovided for visually indicating that the evice is functioning properly, said means comprising for example a cam 110 mounted on the shaft 91 of rotary member 100 and adapted to engage contact s rings 112 and 113 which cooperate with xed contacts 114 and 115 to close circuits leading to indicating lamps 116 and 117 mounted on the front of the casing. The respective contact springs 112 and 113 may be provided with insulation indicated at 118 at the points where they are engaged by cam 110 aforesaid.

Various other instrumentalities mounted on the casing for the apparatus, will be refcrred to in connection with the electrical circuit connections, which are shown in Fig. 9. The apparatus is adapted for encrgization from an alternating current service circuit (for example 110 volt) indicated at 120, connectcd through a main switch 119 to the primary winding of transformer 4. This transformer may have two secondary windings 121 and 122. winding 121 being adapted to produce say 110 volts in a main operating circuit and winding 122 being adapted to produce a low votage in an indicating circuit hereinafter described.

The main operating circuit leads from winding 121 by wire 124 to motor 8. From motor 8 a connection 1226 leads to the other side of winding 121. this connection including a variable resistance 128 for regulating f the motor speed, the operating handle for controlling this resistance being mounted on the front of the casing as indicated at 128' in Fig. 1. A connection 127 leads from wire 124 through a resistance to contact 51 for switch 46. and from said switch means a wire 129 leads to switch 14, contact 41 for said switch being connected by wire 130 to one end of the resistance element 96 of the current modifying means. From the other end of resistance element 96 wire 131 leads contact 36 of switch 12 and also by wire 131 to switch 45, the contact 49 thereof being connected by wire 132 to wire 126 aforesaid. and being also connected by wire 133 to switch member 44. It will be noted that contacts 47 and 43 4 shown in Fig. 6 are idle or unconnected contacts and are omitted from Fig. 9. Contacts 40 and 38 are connected as shown in Fig. 9.

A potentiometer 134 is provided, compris- 1' ing resistance or impedance means connected at its ends by wires 135 and 136 respectively to switch members 12 and 13. The operating handle for the potentiometer is mounted on the casing as indicated at 134' in Fig. 1. I.'

From the contact- 37 for switch member 12, a wire 138 leads to a switch 140 whose operating handle is indicated at 140' in Fig. 1. Switch 140 is provided with contacts 141 and 142, contact 141 being connected by wire 14; I

preferably of duplicate construction so as to i provide for rectification of both halves of the alternating current wave. The wires 147 and 148 are connected to the alternating cui= rent input terminals of the rectifier, and the wires 150, 151 are connected to the rectified current output terminals thereof. One side of transformer coil 121 is connected to one input wire 147 of the rectifier, the other input wire 148 being connected to contact 48 for switch 44, said switch having connection by wires 133, 132 and 126 with the other side of the transformer winding 121. One output wire 150 of the rectifier is connected to contact 50 for switch 45. The other output wire 151 of the rectifier is connected through a choke coil 154, wire 152, a double pole switch 155 and 156 and wire 153 to contact 52 for switch 46. Capacities or condensers 158 and 159 may be provided in branches across the rectifier connections for assisting the action of the choke coil in producin a smooth rectified current. A wire 157 leads from wire 151 to a contact 160 for switch arm 156.

The potentiometer 1.34 serves to supply current of any desired voltage to the applicator circuit, one side 161 of such circuit being connected to one end of the potentiometer winding and the other side 162 of said circuit being connected to the movable contact of the potentiometer. The two circuits 161 and 162 may be connected through a pole changing switch 163 and milliammeter174 to the terminals 164 and 165 for making connection to the patient. In Fig. 1, the handle for the pole-changing switch is indicated at 163' and applicators 166 and 167 are shown as connected to the terminals 164 and 165.

The pilot lights 116 and 117 on the casing are connected through wires 168 and 169 to switches 112 and 113 connected by wire 170 to one side of the low voltage 112 of the transformer 4, the other side of each of said pilot lights being connected by wire 171 to switch 15, contact 42 of said switch being connected by wire 172 to the other side of winding 112. The operation is as follows: The primary position of the apparatus is assumed to be that of supplying unmodified alternating current to the patient. In that case the switch means 44, 45 and 46 are in the position shown in Fig.9, but switch means 12. 13, 14 and'15 are in raised position so that switches 12, 13 and 14 connect with contacts 36, 38 and 40 respectively, and switch 15 is out of contact. The current passes from the secondary winding 121 of the transformer 4 through wire 124, resistance 125, wire 127, contact 51, switch 46, wire 129, switch 14, contacts 40 and 38, switch 13 and wire 136 to one side 'of the potentiometer resistance 134. From the other side of the potentiometer the connection is continued through wire 135, switch 12, contact 36, wire 131', switch 45, contact 49 and wires 132 and 126 to the other side of transformer winding 121.

' ing to the voltage of the winding 121 as modified by the resistance 125. The function of the transformer 4 in this case is to apply substantially full line voltage to the apparatus while, removing the apparatus from any ground or main line connection. By means of the potentiometer handle, thepoint of contact with the potentiometer may be varied so as to apply any desired voltage of the applicator circuit 161 and 162 so that in the stated case there is applied to the patient an alternating current (such as represented graphically at a in Fig. 10) of the desired voltage and without any modification by the current modifying means 7, the circuit traced being independent of said current modifying means. This corres onds to one extreme position of the control ing handle 33 and is indicated on the drum 64 by suitable marking, (such as Rapid sinusoidal) which is exposed through the sight opening 81 at this time.

In case a modified current is desired the handle 33 is turned and the shaft 32 thereby operated, and said shaft through the gearing 31, 29 and 28 operates the shaft 26 so as to rotate the cams25 and 61 thereon. At this time the connecting link 74 is at one extreme end of its stroke, the crank wheel 69 being on substantially dead center position so that on the initial movement of the shaft 30 no substantial shiftingof the motor 8 is produced. The position of motor 8 at this time is such that the channel member 82 engages with the means 87 at a point of contact which travels back and forth between the center of rotation of the channel member and one end of said channel member so as to produce an extreme modifying effect as hereinafter, described.

The initial movement of the shaft 30 causes pin or member 24 on lever 19 to pass through the slot 34 in the cam means 25 by the operation of the inclined projection 34 and the inclined face of the slot, so that member 24-passes to the other side of the cam disc 25, and in this operation lever 19 is shifted so as to move the bar 16 and the switches 12, 13, etc., to position shown in Fig. 9. This places the apparatus under control of the current modlfying means, the circuit being traced as follows: from the transformer winding 121 through wire 124 and the connection as traced above to switch 14, thence through contact 41 and wire 130 to resistance winding 96 of the current modifying means and from said winding through wires 131 and 131' to switch 45 and from contact 49 by wires 132 and 126 to the other side of the trans former winding.

The motor 8 is in operation at this time through connection including wire 124, resistance 128 and wire 126, this connection indeed being establishedwhen the main switch 119 is closed irrespective of the operation of the switches 12, 13, etc., but the operation of the motor being without effect when the switches 12, 13, etc., are in initial or raised position as above described. When, however, the switches 12, 13, etc., have been moved to osition shown in Fig. 9, the current modif ying means is connected in the circuit and causes a continual modification or variation of the current by reason of the travel of the brushes 98 and 99 over the resistance wire 96, it being understood that (with the resistance wires extending vertically as shown in Fig. 8) when the brushes are in horizontal position substantially the full voltage applied to the resistance 96 will be taken up by the brushes 98 and 99 and communicated through collector rings 106 and 107 to the potentiometer circuit connections but when the brushes 98 and 99 are in vertical position they will contact with portions of wire 96 which are at zero potential diflerence so that the eflect of rotation of the member 100 is to cause a gradual variation and periodic reversal of the voltage applied to the potentiometer.

If the member 100 is rotated at a uniform rate, the variation of voltage produced thereby Will follow a uniform approximately sinusoidal curve. In the stated position of the parts, however, where the pin 87 is near one outer end of the transverse channel 82 in rotating member 7 8, the effect of uniform rotation of member 78 is to produce a non-uniform rotation of member 86 connected to the modifier disc 100, and the arrangement is assumed to be such'thatthe most rapid motion of member 100 is when it is taking maximum voltage from resistance 95 thereby giving the effect of a sharp peak in the voltage applied to the potentiometer as indicated at 2 in Fig. 10 and the indicator drum '64 is provided with suitable marking to indicate this type of current wave illustrated at b in Fig. 10.

The connection from the brush 98 of the current modifying means is through collector ring 102, brush 106, wire 143, switch 140, wire 138, contact 37, switch 12 and wire 135 to the potentiometer and from the other side of the potentiometer by wire 136, switch 13, contact 39, and wire 145 to brush 107. The mechanical connection by means 88, 89, 90, between rotary member 86 and commutator means 100 is such that the former makes two revolutions for each revolution of the latter, so that the current modifying mechanism effects a complete cycle of speed variation during the period of one-half of a revolution of the rotary contact means. In the'stated position of the control means, the movement of the contact means is rapid during each uarter rotation in which the voltage taken from the resistance means 95 is near a maximum, either positive or negative, and is slow during each quarter rotation when the voltage being taken from the resistance means is near the minimum, therebyproducing the peak effectas stated.

In the rotation of the members 78 and 86, the pin or roller 87 is at certain times in contact with the channel member 82 at a point at or near the center of rotation thereof, and at this time the arm 86 is nearly or quite at rest whereas at other times the pin or roller 87 is in engagement with the channel member 82 near an outer end thereof so that at such times the arm 86 is subject to rapid motion.

By operation of the handle 33, the motor 8 and the rotary member 78 connected thereto may be shifted transversely with relation to the axis of rotation of member 86 so as to decrease the inequality of motion of the arm 86 in the uniform rotation of the member 78, and by this means the peak effect may be reduced as indicated at 0 in Fig. 10.

By a further motion of the operatin handle 33, the axis of rotation of the mem r 78 may be brought into alignment with the axis of rotation of member 86 and the two members 78 and 86 will then rotate in unison and uniformly, producing a sine variation of the sinusoidal alternating current as indicated at d in Fig. 10.

By further operation of the handle 33 the asymmetric action of the channel member 82 with referenceto the pin or roller 87 may be shifted to the other side of the center of ro tation so that the commutator member 100 will move slower at the times when it is taking maximum voltage from the resistance coil 96, and will move more rapidly when the brushes thereon are at minimum potential difference. The effect of this is to produce a dwell or sustained peak effect as indicated at e, the graph f indicating a more prolonged dwell effect and corresponding to the extreme position of the channel members 82 with reference to the pin or roller 87. 6

By operation of the mechanism constituted by members 78, 82, 86 and 57, therefore, the commutator of the current modifying means may be alternately accelerated and retarded so as to produce any desired modification of the current.

In the above described operation, the crank wheel 69 has been moved one half turn in the operation of the handle member 33, producing a complete stroke of the motor carriage in one direction and during this operation the switches have been maintained in position for supplying alternating current to the applicator circuit as above described, subject to modification by the current modifying means.

Further operation of the operating handle 33 will cause cam 25 to cooperate with roller 24 so as to cause cam 61 to cooperate with the pin or roller 60 so as to force the said pin or roller through the slot 62 in said cam and turn lever 57 which operates bar 54 through pin 55 so as to move the switches 44, 45 and 46 to lowered position in which they contact respectively with contacts 48, 50 and 52."

The circuit connection may then'be traced fromone side of windin 121 direct to input wire 147 of the rectifier, and from the other side of Winding 121 throughwire 126,

132 and 133, switch 49 and contact 48 to the a K construction andarrangement of the appaotherinput wire 148 to the rectifier. Rectified current from the rectifier passes through output wire 150, to contact 50, switch 45, wire 131 and 131 to one side of resistance 96, and from the other. side of said resistance by wire 130, contact 41, switch 14, wire 129, switch 46, contact 52, wire 153, switch means 155, 156 (whose uppercontacts are connected by wire 156), wire 152 and choke coil 154 to the other output wire 151 of the rectifier. v V

The effect of these connections is to apply to the potentiometer 134 a rectified current which is subject to almodification by the current modifying means 7 above described. At the initiation of this further movement of the operating handle 33, the crank wheel is just starting on its return movement so that the members 78 and87 are still at relative position corresponding to a sustained peak effect producing current such as indicated bythe graph 9 in Fig. 10 which may be designated on the indicator drum as sustained galvanic or other suitable designation.

In the further movement of the operating handle 33, the asymmetric operation of the rotary means 78 and 87 is reduced as shown at k in Fig 10, and when the axes of rotation are again brought into alignment, a sine variation such as indicated at z in Fig. 10 is produced. Further rotation of the handle 33 produces a peak effect of progressive intensity as indicatedat j and I:. At the end of this return stroke of the motor shifting means, pin 24, passes through slot 35 to the other side of the cam means 25, thus restoring the parts to original position.

By operation of the switch means 155, 156 so as to open connection at 155 and close contact at 156, 160, the choke coil 154 may be cut out, the current passing from contact 160 directly by wire 157 to output wire 151 of the rectifier, with the result that pulsating efl'ect such as indicated in graphs 9 and y" may be produced, it being understood that similar pulsations may be produced in connection with any of the rectified impulses. By shifting switch 140 to contact at 142, the circuit connection may be diverted through wire 144 to brush 108 so as to take off only a half wave at each alternation of the current modifying means, the corresponding graphbeing indicated at g" for one of the rectified wave forms and such half wave impulses may also be produced with pulsations, by cutting out the choke coil. 7

The apparatus described above therefore provides for application to the patientof various forms or modalities of current either alternating or rectified and with various modulations in accordance with the setting of the controlling handle, the character of the currentbeing applied at any time being indicated on the indicator drum. 1

Various modifications may be made in the ratus without departing from my invention, provided that the general principle of operation remains the same. For example, in the mechanism for imparting a variable speed to the current modifying commutator the rotary channel member may be mounted either on the driving member asshown or, by reversal of the construction, the channel member may be mounted on the driven rotary member, suitable modificaitons being made in the operating and indicating means.

Furthermore, while I have described a particular form of current modifying means, it will be understood that I may use any suitable means for establishing moving contact with a resistance means so as to take off a current of continually varying voltage from a supply circuit.

I claim: I

1. In apparatusof the character described, the combination of resistance means, means for applying a definite voltage to said resistance means, contact means mounted to travel over said resistance means to collect current of. varying voltage therefrom, a motor and a variable speed mechanism comprising a rotary driving member operated by said motor, a rotary driven member and variable speed coupling means connecting said rotary driving member and said rotary driven member to operate said rotary driven member at variable speed by constant speed operation of said rotary driving member, in such manner that the speed Variation of the rotary driven member passes through a complete cycle during each rotation of said rotary driven member and means connecting said rotary driven member to said contact means to operate said contact means through a complete cycle of variation during each half rotation of said rotary driven member, so as to effect alternative rapid and slow movement of the contact means in successive 'quarter revolutions of said driven member and thereby cause modification of the current delivered by said contact means. v a.

2. In apparatus of the characterdescribed, current modifying means comprising a modifying resistance winding having an exposed portion, a rotary commutator having contact means adapted to travelv over said exposed portion of the winding and provided with means for delivering current from said contactmeans, means for supplying current to for rotation by said motor at uniform speed, a rotary driven member connected to said rotary contact member to operate the same and means connecting said rotary drivin member and said rotary driven member an comprising a channel means on one of said members and a projection of the other of said members adapted to engage said channel means to effect rotation of the driven member by rotation of the driving member and means for shifting the said motor and driving member transversely to the axis of rotation of said rot: ry driving member to vary the engagement between therotary driving member and the rotary driven member so as to modify the s ed of the driven member in different portions of rotation thereof.

3. Apparatus of the character described, comprising a current modifying resistance means, circuit connections for supplying current to said resistance means, a rotary commutator having two contact means adapted to travel over said resistance means for taking current of variable voltage therefrom, applicator circuit connections adapted to receive current from said travelling contact means, an electric motor, operating circuit connections for said motor, a rotary driving member connected for operation by said motor, a driven member, said driving and driven members being provided with means for interengagement and for varying the point of engagement with reference to the centers of rotation of said members, and manual controlling means and mechanism operated thereby to shift the electric motor in either direction throughout a definite stroke so as to vary the point of engagement of the rotary driving and driven members, and thereby accelerate o'r retard the motion of the commutator to vary the current delivered thereby.

4. An apparatus as set forth in claim 3 and comprising in addition, means in connection with the connections for supplying current to the modifying resistance means, for supplying alternating or direct current alternatively to said resistance means.

5. An apparatus as set forth in claim 3 and comprising in addition, means in connection with the connections for supplying current to the modifying resistance means, for supplying alternating or direct current alternatively to said resistance means, and switch means connected for operation by said manual controlling means, for changing the connections from alternating current to direct currentconnections or vice versa.

6. Apparatus of the character described, comprising alternating current supply connections, a current modifying resistance, a rectifier, switch means for connecting said modifying resistance means to the alternating current supply connections directly or through said rectifier, a rotary commutator cooperating with said resistance means to take therefrom current of a voltage continually varying and reversing with the rotation of said commutator, current delivery circuit connections for delivering current from said commutator, an electric motor connected for operation from said supply connections, manually operated means for shift- 7 Apparatus as set forth in claim 6 and comprising in addition, means including a switch and also including contact means, in connect-ion with said commutator for taking ofi' current in one direction only therefrom.

8. Apparatus as set forth in claim 6 and comprising in addition, a choke coil in the circuit connections of said rectifying means and switch means for placing said choke coil in or out of operative connection.

, 9. In apparatus of the character described, current modifying means comprising a modifying resistance winding having an exposed portion, a rotary commutator having contact means adapted to travel over said exposed portion of the winding and provided with means for delivering current from said contact means, means for supplying current to said resistance winding, applicator circuit connections for receiving current from said current delivering means, and means for operation of said rotary commutator comprising a motor, a rotary member connected for rotation by said motor at uniform speed, a rotary driven member connected to said rotary contact member to operate the same, a coupling means on one of said members extending diametrically thereof and means on the other of said members adapted to engage said coupling means to effect rotation of the driven member by rotation of the driving member and means forshifting the said motor and driving member transversely to the axis of rotation of said rotary driving member to vary the engagement between the coupling means and the means for engaging the same so as to modify the speed of the driven member in different portions of rotation thereof.

10. Apparatus of the character described, comprising a current modifying resistance means, circuit connections for supplying current to said resistance means, contact means adapted to travel over said resistance means for taking current of variable voltage therefrom, rotary operating means for said contact means, applicator circuit connections adapted to receive current from said traveling contact means, an electric motor, operating circuit connections for said motor, a rotary driving member connected for operation by said motor, a rotary driven member connected to operate the rotary operating means for the same contact means, said driving and driven members being provided with means for interengagement and for varying 10 the point of engagement with reference to the centers of rotation of said members, and manual controlling means and mechanism operated thereby to shift said driving member in either direction throughout a definite 'stroke so as to vary the point of engagement of the rotary driving and driven members, and thereby accelerate or retard the motion of the commutator to vary the current delivered thereby.

In testimony whereof I have hereunto subscribed my name this 3d day of October, 1929.

EDGAR J. ROSE.

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