US1716389A - A cobpobation of delax - Google Patents

Description

- .Filed March 12, 1924 2 Sheets-Sheet Z IUEHZ'Ff- June 11 1929. T 1,716,389

' ELEQTRICAL APPARATUS Filed March 12,1924 2 Sheets-Sheet 2 fnueztzlar' Patented June 11, 1929.

UNITED STATES PATENT OFFICE.

FRANK F. STARR, OF DAYTON, OHIO, ASSIGNOB TO DELCO LIGHT COMPANY, 01: DAY- TON, OHIO, A CORPORATION OF DELAW'ARE.

ELECTRICAL APPARATUS.-

Application filed March 12, 1924. Serial No. 698,777.

The present invention relates to electrical generating and supply systems including an engine and a dynamo which is adapted to function either as a motor to crank the engine or as a generator driven by the engine, and more particularly the invention relates to the control of the electrical circuits.

The present invention is an improvement of the electrical system shown in the copending application of Kettering and Federle filed Sept. 23, 1922, Serial No. 589,991, (Docket 17 2) and an improvement of the controller shown in the copending application of Federle filed October 3, 1922, Serial No. 592,155 (Docket 174). In those applications and in the present application, there is disclosed a dynamo having series and shunt field windings, the series winding being effective only when the dynamo functions as a motor to provide a heavy torque for engine cranking, said winding being rendered inoperative after the engine becomes self operative and drives the dynamo as a generator. A controller is provided having series and shunt magnet windings. During the cranking operation, these windings oppose one another and, during the generating operation, assist one another whereby respectively to render the series winding of the dynamo effective during cranking operation and ineffective during generating operation. Through other instrumentalities this controller functions to interrupt the cranking circuit when the engine does not start within a reasonable time. During generating operation, if the engine stops, the controller operates by reason of the reversal of current in the series magnet winding to interrupt the cranking circuit.

It is one of the objects of the present invention to improve the electrical system disclosed in said applications whereby to increase the reliability of said system in performing the operations herein referred to, regardless of the size of engine and the amount of cranking current required, and regardless of whether the speed of the engine is initially limited by a governor such as a governor responsive to current consumption. A further object is to improve the type of controller disclosed in the Federle application so as to secure greater reliability particularly in respect to assuring that when the controller contacts are once actuated to open or closed'position, these contacts will remain in the required position.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a side elevational view of my 1111' proved controllert Fig. 2 is a sectional view taken on the line 22 of Fig. 1, showing contacts of the con troller open. 1 I

- Fig. 3 is a sectional view similar to that of Fig. 2 with the contacts of the controller closed; and

Fig. 4 is a diagrammatic view of an improved battery charging system, showing the persent type of controller applied thereto.

In the drawings, the controller may be termed a relay 20 supported by a plate 21, and including a C-shaped magnetizable frame 22, suitably held upon the plate 21. Frame 22 carries a bolt 23 and a non-magnetizable tube 25 which supports magnet winding 26, having a relatively largenumber of turns of fine wire. Tube 25 also supports a magnet winding 28 of fewer turns of relatively coarse wire. Bolt 23 terminates above the lower end of magnet winding 26. The tube 25 provides a guide for a magnetizable plunger 30 and is connected with a non-magnetizable threaded rod 31 which carries nuts 32, 33, 34, and a nonmagnetizable weight 35. A lever 37 is provided having ears 38 by which said lever is pivotally mounted on the fulcrum pin 39 se-. cured to the plate 21. Rod 31 passes through lever 37. Nuts 33 and 32 are located on one side of the lever and nuts 34 and weight'35 on the other. p

WVinding 28 is connected at one end with terminal 40 grounded at frame 22 and at the other end with terminal 41; one end of the winding 26 is connected with terminal 40 and the other end of said winding is connected to terminal 43. Terminals 41, 42, and 43 extend through plate 21 and are insulated therefrom. Terminal 42 supports a contact 45 adapted to be engaged by contact 46 carried by one end of the lever 37. Lever 37 carries at its other end a weight 48 secured thereon by screws 49. lVeight 48 normally tends to overbalance the lever 37 to maintain contact 46 in engagement with contact 45. The weight of the plunger 30 plus that of weight 35 is suficient to overbalance the weight 48 and when the plunger is released from its attracted position. The downward movement of lever 37 is limited by an adjusting screw 50 locked in position by a lock nut 51, said lever 37 abutting the head of said screw and thereby limiting the movement thereof.

The present invention is particularly applicable to battery charging systems, such as that illustrated in Fig. 4. While the present invention is susceptible to other applications, this particular use will serve as an example to explain its operation more clearly.

Referring to Fig. 4, is a dynamo which is driven as a generator by engine 61 and is connected in circuit with a storage battery 62 to charge the latter. Dynamo 60 includes a shunt field winding 63 connected across brushes 64 and 65 and a series field winding 66. The control elements for controlling the electrical connections between the dynamo 60 and the battery 62 include a starting switch relay 68 and a starting switch 69, the present improved relay 20 which functions as a load switch relay, a load switch 70, a cranking cutout 71 and an ampere-hour meter 72.

The starting switch relay 68 includes an arn'iature 74 connected with wire 75 adapted to en gage a contact 76 which in turn is connected with a wire 77. Armature 74 is adapted to be attracted, so as to engage contact 76, by high resistance windings 7 9 which is connected at one end to wire 80 and at the other end by wire 7 8 to wire 93; said armature is also adapted to be attracted by a high resistance winding 81 connected at one end with wire 82 and at the other end to wire 78, and by series winding 83 connected at one end to wire 84 and at the other end to wire 85.

The starting switch 69 includes an armature 87 which is connected to a wire 88 and is adapted. to engage contacts 89 and 90. Armature 87 is raised into engagement with the contacts 89 and 90 by winding 92 connected at one end with wire 93 and at the other end to wire 94. Contacts 89 and 90 are connected with wires 95 and 93, respectively.

The load switch relay connections are as follows: Terminal 40 is connected to wire 84; terminal 41 is connected to Wire 97; terminal 43 is connected to wire 88; terminal 42 carrying contact 45 is connected with a wire 98 and the frame 22 is connected to wire 84 by ter- .1ninal40.

The load switch includes an armature 101 connected with a wire 102 to which wire 80 is connected. Armature 101 carries a contact 103 which is arranged to engage contacts 104 and 105 when the armature is in its unattracted position. Contacts 104 and 105 are connected, respectively, to a wire 95 and a wire 106. WVhen the armature 101 is in its attracted position, it engages contacts 107 and 109 connected respectively with wire 108 and the wire 95. The load switch also includes a winding 111 which when energized will attract armature 101.

The cranking cutout 71 includes a nonconducting base 113 which carries a bi-metal blade 114 and a pivotally mounted lever 115 carrying the contact 116 which is arranged to engage a contact 117 carried by the base 113. A spring 118 normally tends to rotate lever 115 to separate contact 116 from 117. The blade 114 forms a latch for lever 115 and normally maintains the contacts in engagement. The blade 114 will bow upwardly when heated to release lever 115. Blade 114 is arranged to be heated by heating coil 120 connected at one end by a wire 121 to wire 106 and at the other end to wire 75.

The incoming fuel to the internal combustion engine is heated by heating coil 123 located within the engine intake and is connected to wires 84 and 106.

An ampere-hour meter 72 is located in the battery charge circuit, it being connected to wire 84 and by wire 124 to the negative side of battery 62. The ampere-hour meter 72 measures quantity of current passing to and from the battery. An indicator hand 125 is carried by shaft 126 which is actuated by the meter 72. Shaft 126 also carries a lever 127. Lever 127 is rotatably mounted on the shaft 126 and carries at its end studs 128 and 129 which are arranged to be engaged by the hand 125. Meter 72 carries a lever 130 carrying contact 131 which is connected to wire 82 and is arranged to engage a contact 132 connected with wire 84. Lever 130 is connected with a spring 134 which in turn is connected to stud 129. During battery discharge the hand 125 moves in a clockwise direction and engages stud 129, and after the battery has been discharged to a predetermined state, hand 125 will have moved the lever 127 far enough to actuate lever 130 whereby contact 131 ongages contact 132. While the battery is being charged the hand 125 moves in the opposite direction and by engaging stud 128 will cause the separation of contact 131 from contact 132.

Operation of the plant.

When the battery 62 has been discharged to such a state that contact 131 engages contact 132, a circuit will be completed to winding 81 of relay 68 as follows: Battery 62, wire 93, wire 78, winding 81, wire 82, contacts 131, 132, meter terminal for wire 84, ampere-hour meter 72, wire 124 to the other side of the battery. Energization of winding 81 will cause armature 74 to engage contact 76 to establish the following circuit: wire 93, starting switch winding 92, wire 94, contacts 117 and 116, lever 115, Wire 77, contact 76, armature 74, wire 75, wire 84 on the other side of the line. WVhen the winding 92 is energized, contacts 89 and 90 are closed by armature 87 to establish the following cranking circuit: wire 93, contacts 90 and 89, wire 95, a wire 140, series field winding 66, wire 108a to dynamo brush then through dynamo to brush 64, wire 97, relay winding 28, wire 84 to the negative side of the battery. Since shunt field winding 63 is connected across brushes 64 and 65, the dynamo will function as a compound wound motor to drive engine 61. WVhen armature 87 engages contact 90, a circuit is also complete to the shunt winding 26 of relay 20 by wire 88 which is connected with the armature 87 and terminal 43. During the cranking operation the direction of current flow in winding 28 causes a magneto motive force to be created which opposes the magneto motive force of shunt winding 26 whereby the armature 46 will not be attracted.

When the engine 61 becomes self operative and drives the dynamo as a generator at a speed sufficient so that the voltage of the dynamo exceeds that of the battery, there will be a reversal of current in winding 28 which will produce a magneto motive force which will assist the magneto motive force of shunt winding 26 and when substantially one ampere of generating current passes through winding 28 the accumulative motive force of both windings is sufficient to raise the plunger 30 to cause contact 46 to engage contact 45 whereby winding 111 of load switch 7 0 is on ergized as follows ire 95 on the positive side winding 111, wire 98, contacts 45 and 46,.frame 22, to wire 84 on the negative side. WVhen winding 111 is attracted contact 103 will separate from contacts 104 and 105 and armature 101 will engage contacts 107 and 109 to short circuit the series lield winding 66 of dynamo 60 by wire 108. The dynamo will then function as a shunt wound generator to charge the storage battery.

During the cranking operation before contact 103 is separated from contacts 104 and 105, a circuit is complete to the fuel heating coil 123 over the circuit including wire 93, contacts 90 and 89, wire 95 contacts 104, 103, 105, wire 106, heating coil 123, wire 122 to the negative side of the battery. A circuit is also completed to cranking cutout heating coil 120 which circuit includes awire 121 con nected to wire 106, heating coil 120, wire to the negative side of the battery. If the plant does not start within a reasonable time, the blade 114, being heated by wire 120, will release lever 115 to separate contact 116 from 117 to interrupt the circuit to winding 92 of starting switch 69 to break the cranking circuit at contacts 89 and 90.

A work circuit, for supplying small current such as lights or the like, is connected across the battery and includes a wire 142 connected to wire 93, lights 143, and Wire 85, starting switch series windings 83 and wire 84 which is connected to the other side of the battery. hen there is an excess demand in the lighting circuit, sufficient ampere turns will be produced by the winding 83 to close the armature 74 to start the plant automatically as was previously described.

Another work circuit for translating devices which consume a relatively large amount of current is provided which is connected to wire 102 on the positive side of the system, and, by wire 85 on the negative side. This work circuit is herein'termed power circuit which is herein shown as being adapted to supply current to a motor 145 adapted to be controlledby switch 146. The dynamo mustfunction as a generator before sufficient current is supplied to the power circuit for operating same.

The plant can also be automatically started by the switching on of the device in the power circuit. Byfclosing switch 146 a circuit is complete for the starting switch relay winding 79 as follows: battery 62, wires 93 and 78, winding 79, wires and 102, motor 145, switch 146, wire 85, a winding 150, relay winding 83 of starting switch relay 68, to wire 84 on the other side of the battery. The high resistance winding 79 limits the amount of current and the motor will not operate. Energization of winding 79 will cause the attraction of armature 74 to complete the automatic starting operation.

Operative current for the motor 145 is not supplied thereto until the plant is self operated, that is, after the load switch 70 has been closed. The operating circuit for the motor 145 is completed as follows: positive generator brush 65, wire 106, contact 107, armature 101, wire 102, motor 145, switch 146, Wire'85, winding 150, series winding 83, wire 84, series winding 28 of relay 20, wire 97 to nega tive generator brush 64. The armature 74 of relay 68 will then be held in close position by the series winding 83.

The generator output is controlled by throttle governor 148 including a solenoid plunger 149 and a winding 150 located in the circuit 85. It will be noted that coil 150 is not located in the battery charging circuit and during the battery charging operation, and if there is no demand in excess of the certain amount in the work circuits, the output of the generator is substantially constant,

(approximately 15 amperes).' The throttle valve is constructed so that substantially 15 amperes of current are necessary in the coil 150 before the throttle is actuated to increase the speed of the engine. Therefore, if a device or devices are connected in the lighting or power circuit and are consuming less than 15 amperes, the generator output is not increased and the battery will only receive current to the amount of the difference between that consumed in the light and power circuit and the amount generated.

If the current demand in the work circuit exceeds the battery charging rate (approxi mately 15 amperes) the throttle will be opened accordingly and the battery will float on the line, receiving only, if any, a small amount of current.

It, when the battery becomes fully charged and there still exists a demand in the work circuits for current in excess of a certain amount (approximately 12 amperes) the plant will continue to operate, the starting switch relay of armature 7 4: being held closed by the winding 83. However, if this demand ceases, the plant will stop automatically.

If the battery is fully charged and there is such a demand on the work circuit as to maintain the plant operative, the work circuit will consume substantially the entire output of the generator and the battery floats on the line. The purpose of placing the throttle control winding 150 in the work circuit and constructing a throttle valve so that the speed of the plant is not changed until the required load is supplied to the work circuit will be apparent when considering same being applied to a system as is herein described in which it is desirable to maintain the plant operative for supplying current to the work circuit even though the battery is charged. If the battery becomes fully charged and if less current is being consumed in the work circuits than approximately twelve amperes, the plant will stop due to the falling out of armature 741- of relay 68. However, if the work circuits are consuming enough current to maintain armature 74 closed, the plant will remain operative. The throttle valve regulates the speed of the engine and likewise the generator output so that the current output is substantially equal to the demand in the work circuits, and therefore the fully charged battery will receive only a small amount, if any, current.

If during the generator operation the engine 61 ceases to function properly due for instance to the lack of fuel, there will be a reversal of current in the circuit between the dynamo and battery and likewise in the series winding 28 of load switch relay 20, and when the discharge from the battery amounts to approximately 6 amperes the plunger 30 will fall out and move contact 46 out of engagement with contact 45 to interrupt the circuit to winding 111 of load switch 70. The arma ture 101 of load switch will then fall out to reconnect the heating coil 120 of cranking cutout 71, and at the same time establish the cranking circuit including the series field winding 63. The engine cranking operation will continue until the bi-metal blade 11a has bowed upwardly sufficiently to release lever 115 and separate contact 116 from 117 to thereby interrupt the cranking circuit at contact 89 and 90 by interrupting the circuit to the starting switch winding 92.

The present invention can be used advantageously with internal combustion engine plants wherein the engine cranking current is relatively small. As an illustration, one specification is given.

Let the minimum engine cranking current be 9 or 10 amperes at 32 volts. The series winding 28 of relay 20 which is responsive to battery charge and discharge carries this current. One condition placed upon this relay 20 is that its contacts must not close when 10 amperes or more battery discharge current is flowing through winding 28, as during that period when the engine is moved from a static position, at which time a relatively large amount of current is consumed by the dynamo 60. The relay 20 must be constructed to open its contacts in response to a battery discharge current which is less than 9 amperes (that which is required for cranking) by a safe margin in order to allow for the possibility that the battery discharge during cranking would not amount to 9 ampercs. This is important when it is considered that the relay 20, by permitting its contacts to open serves to cause the load switch 70 to permit closing of the circuit to the heating coil 120 of the cranking cutout 71, and that said cutout 71 will cause the switch 69 to disconnect the cranking circuit when the battery discharge exceeds a certain amount. Since, after the plunger 30 has once been attracted, it requires less ampere turns in the shunt winding 26 to maintain the plunger in the raised position than is necessary for lift-v ing same to this position, due to the decrease in the air gap between the plunger 30 and the core or bolt 23, and since as will be explained later, itis desirable to attract the plunger when approximately one ampere of current is being generated, it requires approximately 6 amperes battery discharge current opposing the magnetic effect of shunt winding 26 before the ampere turns within the shunt are reduced sufliciently to release the plunger 30.

The contacts of relay 20 should close when the generator current is small because, before the load switch 70 closes to change the characteristics of the dynamo from a differential compound generator to a shunt generator, the dynamo output is limited by the bucking series field. The dynamo speed is also limited by the engine throttle governor. It is therefore desirable that the relay contacts close when one ampere of current is generated in order that, as soon as possible after the engine becomes self operative, the characteristics of the dynamo will be changed by the load switch 70 to a shunt generator and its gener ating output will be increased.

The circuits are such that all of this one ampere passes through the relay winding 28. None is diverted for other purposes since heating coils 120 and 123 are supplied with current from the battery. This circuit arrangement is advantageous in order that the load switch relay contacts will close at the governed engine speed: but somewhat disadvantageous at, the time when the relay con tacts open.. 1 p 7 Assume that the engine becomes inoperative due to the lack of fuel; As the engine speed decreases, the charging current falls to zero and the discharge increases to approximately 6 amperes when the contacts of relay 20open to cause the load switch 7 0 to open to prevent battery discharge to the power circuit and to cause the cranking cut-out heating coil 120 to become operative to efiect the interruption of the cranking circuit. Before the contacts of relay (20) open, the dynamo will operate as a shunt wound motor. Since the shunt field alone is operative, the field will berelatively weak and the motor will operate at a relatively high speed. When the contacts of relay 20 open to cause the load switch to change the characteristics of the dynamo-from a shunt motor to an accumulativecompound motor, the G. E. M. F. of the dynamo will be relatively great for an in stant. Since none of the momentary current is diverted into coils 120 or 123 and all must pass through coil winding 28 of relay 20, there is a tendency for the contacts to close again to cause the load switch 70 to interrupt the circuit to the cranking cutout coil 120 and to change the characteristics of the dynamo back to a simple shunt motor. Were it not for certain constructions to be described, this v ating and storage system, of a dynamo adapted to functlon as a motor or as a generator,

cycle of operation might be repeated indefinitely, that is, the. contact 4:6 would moveup and down into engagement intermittently instead of remaining down to maintain the relay contacts open.

Therefore another condition is imposed upon relay 20; and that is the relay 20 must not close its contacts by reason of the momentary high G. E. M. F. of the dynamo when operating as an accumulative compound motor at the speed referred to; i

Therefore the relay 20 is so constructed that the contacts 45 and 46 are not separated to interrupt the circuit to the load switch winding 111 until the speed of the engine has decreased to such an amount that the current value in coil 28, when the series field is rendered operative, will not create sufficient ampere turns to reconnect said contacts. To accomplish this result the plunger 30 is provided with a loss motion connection with the lever 37, that is, the plunger 30 and weight 35 can fall a substantial distance before the nut 33-carried thereby will engage the lever 37 to actuate same. The weight 48 maintains contact 46 closed with contact 45 while the plunger is falling out; however, after the current in winding 28 decreases to a certain,

amount, the weight of the plunger 30. and

weight 35 is sufficient to overcome the weight 48 whereby the contacts are separated. The adjustment of the nuts is such that the plunger 30 will fall to such a distance before the contactsare open that the gap between the plunger and the core 23 is such that the momentary efl'ectiveness of the shunt winding 26,

ating and storage system, of a dynamo adapted to function as amotor with certain field characteristics or as a generator with different field characteristics, a. prime mover connected therewith, a storage battery adapted to be connected with the dynamo, andconctrol means for putting the prime mover in operat1on to drive the dynamo as a generator,

said control means including a relay winding, a relatlvelyheavy current consuming device connected to the battery at a point between the battery and said winding, a switch for changing the characteristics of the dynamo and for rendering said device inoperative,

said relay being responsive to operation of the engine for actuating said switch.

2. The combination, in an electric genersaid dynamo having a plurality of characteristics, a storage battery, a circuit adapted to connect the battery with thedynamo, conadapted to change said characteristics of said dynamo, the current flow in said circuit be ing afiected by the change of the dynamo characteristics, said relay winding being as-. sociated with the connecting circuit and adapted to be affected by the change in current flow and adapted whenso aiiected to tend to actuate said contacts to rechange the characteristics of said dynamo, saidrelay including means for preventing the actuation of the said contacts to rechange the said dynamo characteristics. v

3. The combination, in an electric generatingandstorage system, of a dynamo adapted to function as a motor oras a generator, said dynamo having a plurality of field circuits wherebyit operates with diiferent characteristics; a storagebattery; circuitconnection between the battery and dynamo; control means for connecting the dynamo with the battery, said control means including a relay having a winding, contacts controlled by said relay for controlling the field circuits whereby the characteristics of said dynamo are changed, the current flow in said circuit connections being affected by the change of dynamo characteristics, said relay winding'being associated with the connecting circuit and adapted to be affected by the change in current flow and adapted when so affected to tend to actuate said contacts to rechange the characteristics of said dynamo, said relay including means for preventmg the actuation of said contacts to rechange the said dynamo characteristics.

4. The combination, in an electric generating and storage system, of a dynamo adapted to function as a motor or as a generator,

said dynamo having a shunt field circuit and a series field circuit whereby it operates with different characteristics; a storage battery; circuit connections between the battery and dynamo; control means for connecting the dynamo with the battery; said control means including a relay having a winding and contacts controlled by said winding for rendering the series field circuit effective whereby the characteristics of said dynamo are changed from shunt to series and shunt, the current flow in said circuit connections being aifected by the change of dynamo characteristics, said relay winding being associated with the connecting circuit and adapted to be affected by the change in current flow and adapted when so affected to tend to actuate said contacts to rechange the characteristics of said dynamo from series and shunt to shunt characteristics, said relay including means for preventing the actuations of said contacts to rechange said dynamo characteristics.

5. The combination, in an electric generating and storage system, of a dynamo adapted to function as a motor or as a generator, said dynamo having a plurality of characteristics, a storage battery, a circuit adapted to connect the battery with the dynamo, control means for connecting the dynamo with the battery and for changing the characteristics of the dynamo when said dynamo functions as a motor, including, a relay having a windduring a certain movement of said magnetic element.

6. In an electrical generating system, the combination with a dynamo adapted to 11110 tion as a motor having a plurality of characpreventing the operation of the switch until the element is in a stable position.-

7.- In an electrical generating system, the combination with a dynamo adapted to function as a motor and having a plurality of field circuits for operating same with diiferent characteristics; ofa source of current; a circuit adapted to connect the dynamo with said source of current, the current in said circuit being affected by a change of dynamo characteristics; control means for changing the characteristics of the dynamo, said control means including a relay having a Winding in the connecting circuit, a magnetic element actuated by said winding, a switch actuated by the element and adapted to control said field circuits, and means for preventing the operation of the switch until the element is in a stable position.

8. In an electrical generating system, the

' combination with a dynamo adapted to function as a motor having a plurality of characteristics; of a source of current; a circuit adapted to connect the dynamo with said source of current, the current in said circuit beingaffected by a change of dynamo characteristics; control means for changing the characteristics of the dynamo, said control means including a relay having a winding in the connecting circuit, a magnetic element actuated by said winding, a switch actuated by the element and adapted to change the characteristics of the dynamo, alost motion connect-ion between said switch and element, and means for maintaining said switch in its initial position during a certain movement of said element.

9. The combination, in an electric generating and storage system, of a prlme mover supplying current to the battery during generating operation, the current value in said circuit being affected by a change of field circuits of the dynamo; and control means for controlling the battery, and dynamo connection including a relay winding connected in said circuit, a magneteleinent actuated by said winding, a switch actuated by the element and adapted to control the field circuits of the dynamo to change the characteristics thereof, and means for preventing the operation of the switch until said element is in a stable position.

In testimony whereof I hereto aflix my signature.

FRANK F. STARR.

Images