US1695353A - Electrical generating system - Google Patents

Description

De.1s,1928. .1,695,353 F. F. STARR ELECTRI CAL GENERATI'NG SYSTEM Filed Nov. 16, 1925 Patented Dec. 18, 1928.

UNITEDI STATES PATENT oFFlcE. f

FRANK F. STARR, OF DAYTON,` OHIO, ASSIGNOR TO DELCO-LIGHT COMPANY, OF DAYTON,

OHIO, A CORPORATION OF DELAWARE.

ELECTRICAL GENERATING SYSTEM.

Application tiled November 16, 1925.

This invention relates to electrical generating systems and more particularly to the type of system which includes an internalcombustion engine for operating a dynamoelectric machine which is used as a motor with battery current for starting the engine, and when driven by the engine, as a. generator for charging the battery and supplying electrical lighting and power circuits.

One `of the objects of the present invention is to provide for starting the plant easily when there is a demand for current. This is accomplished in the present apparatus by a controller responsive to engine temperature for automatically causing the engine to opcrate before its ten'iperature is reduced to such a low' value, as in cold weather, that it would be diflicult to start the engine. The engine is stopped automatically after it has warmed to suoli a degree that a substantial period will elapse be'lore the engine temperature is reduced to a low value, requiring the engine to be started again. Apparatus rcsponsive to epgine temperatures is provided for controlling the carburetor in order to provide a rich fuel mixture for starting and to reduce the richness of the mixture as the engine becomes warmer. One of the novel features of the invention is the use of a single thermostatic element in heat-receiving relation to the engine for actuating the controller and carburetor-controlling apparatus.

A further object of the inventiony is to provide a system ol controlling/fi primemover dynamoplantso that it will be started automatically in response to a certain low degree of engine temperature, or in response to a certain demand in one work circuit, or' in response to a certain excess demand in another work circuit, and so that the plant will be stopped when these current demands cease, but i-nfany event providing for stopping the engine only after the engine temperature has reached a certain relatively high degree.

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

In the drawings:

The single figure is a wiring diagram showing one form of the invention.

Referring to the drawing', 10 designates an Serial No. 69,311.

internal-combustion engine which drives a dynan'io-electric machine l1 through any suitable mechanical drive such as pulleys 12 and 13 and belt 14. Dynamo 11 includes a shunt field winding 15 and series field winding 16, the latter being used when the dynamo functions as a motor to start the engine.

Dynamo 11 is used to supply current for charging a storage battery 17 or for operating electric lamps 18 or electric motors 19. Ignition for the engine is provided by ignition coil 20 having a primary winding 21 which is connected in series with battery 17 and a timer 22 which is operated by the engine. Coil Q0 includes a secondary23 which is connccted with an engine spark plug 24.

The engine 10 has a carburetor 25 provided with an air inlet port .26 controlled by a plate valve 27 which is adjusted by a bimetallic thermostat blade 28 having its fixed end in good thermal contact with the engine cylinder or cylinder head. A bracket 30 carrying stops 3l` and 32 operates a snap switch 33 which isl diagrammatically represented by levers 3l and pivoted at 36 and connected by a spring 37. Lever 34 is movable between stops 34"* Vand 34h, and lever 35 is movable between a contact 38 and a stop 39. Lever 34 is in the path of movement of stops 31 and 32.

As the engine temperature decreases, the thermostat will bow upwardly, as viewed in the drawing, to close the air port 26 and to cause the lever to engage the contact 38 when a predetermined low temperature is reached. By means of automatic apparatus, to be described, the engine will be started. The closing of air port 26 causes the carburetor to be choked and the engine primed. The temperature at which the switch 35-38 is closed may be below the normal low temperature to which the plant is subjected, but is not so low a degree that the-engine can-be started only with dilliculty, if at all.

As the engine o crates, its temperature increases to cause t e blade 28 to bow downwardly to decrease the richness of the fuel mixture gradually from a starting mixture, to a normal running mixture, and also to open the switch 33 bythe engagement of stop 31 with lever 34 when a certain relatively high engine ktemperature has been reached. By means to be described, the opening of switch 33 will cause the plant to stop, unless meanwhile a demand for current has arisen.

The present invention, therefore, provides for the eontrc if the engine carburetor and the control ot starting and stopping the plant by a single thermostat located in thermal contact with engine parts.

The invention is adapted for use with various automatic starting and stopping systems tor prime-mover-dynamo plants. Such a system is disclosed in the copending application of Kettering Se Federle. Serial No. 589.991, liled September 23, 1922, and includes a starting switch relay 40 which functions in response to a certain demand for current to cause a starting switch to connect the battery 17 with dynamo 11 to operate the latter as a motor to crank the engine. After the engine becomes self-operative and drives the dynamo 11 as a generator, and when a certain amount. of current is generated, a load switch relay 8O will operate to cause the load switch to connect the dynamo in such a manner as to supply the current demanded. `When the demand ceases, the ignition circuit will be interrupted, the engine will stop and the dynamo will be automatically disconnected from the battery and other translation devices. In case the engine tails to start. within a certain time, the cranking cut-out will operate to interrupt the ignition circuit and to interrupt the circuit between the battery and dynamo so that the dynamo cannot function as a motor. In this manner. undue discharge to the storage battery is prevented if the engine fails to start.

The starting switch relay 40 includes a winding 41 which may be connected withthe battery 17 by a switch including a stationary contact 42 connected by wire 43 with coil 41 and a movable contact 41 operated by a lever 45 and connected by wire 46 with battery 17. By means well known to those skilled in the art, an ampere-hour meter 48 causes contacts-d2 and 14 to be separated when the battery has been discharged a certain amount, and to be engaged after the battery has been charged a certain amount. Ampere-hour meter 4.8 is connected by wire 19 with the battery 17, and is connected with a wire 5() leading to the dynamo 11 I The winding 41 may be connected with the. battery 17 by the closing ot contacts 35 and 38. Contact 35 is connected by wire 51 and wire 46 with battery 17; and Contact 3S is connected by wire 52 and wired?) with coil s1 when the magnet coil 11 is connected with the battery 17,I and an armature 56 will be attracted to connect switch contacts 57 and 59. rthis operation will eiect the operation of the starting switch 70 in a manner to be described.

The relay l0 includes other magnet coils which are capable of attracting the armature 56. @ne of these coils is designated by numeral 59 and is connected with wire 50 and with wire 60 to which the lights 18 are also connected. lhen there is demand for lighting current in excess of a certain amount, the magnet coil 59 will be energized sullicient ly to attract armature 56 into circuit-closing position.

The starting switch relay 40 includes still another magnet coil 61 which when energized will cause movement of the armature 56 to connect contacts 57 and 58. Coil 61 is responsive to the closing ot' one of the switches 19a located adjacent a motor 19 or other translation device and connected with a wire 62 which is a part ot the power circuit including the motor 19. The other end of the magnet coil 61 is connected with a wire 63 which is connected with the battery 17 through wires 51 and 46.

The starting switch 7 O includes a magnet coil 71 which is energized by the connections ot contacts 57 and 58 by the armature 56. lVhen energized coil 71 attracts an armature P2 into position lor connecting contacts 73 and 7l. One, end ot coil 71 is connected with wire 63 and the other end with a wire 75 leading to a terminal of the cranking cut.- out 110. The contact 73 is connected with a wire 76 leading to one of the contacts of load switch relay 80. The contact 7l is connected with wire 77 leading to a dynamo brush 7 S. The pivot point of the armature 72 is connected by wire 79 with the load switch relay 80. i

The load switch relay S0 includes magnet trame 81 supporting a stationary core 82 and an armature 83 pivoted at S1. Armature 83 is connected with a plunger 85 which extends within a magnet winding 86 and partway within a magnet winding 87 which surrounds the core 82. `Winding S6 is connected with wire 79 and with wire 50. vinding 87 is connected with a contact. S8 which is connected by wire 76 with contact 73 of the starting switch 70. The other end ot winding 87 is connected with wire S9 which is connected with one end of the series field winding 16 ofthe generator 11. For a more detailet description of the starting switch relay, reference is made to the copendingapplication-of Joseph C. Feder-lc. Serial No. 592.155, filed october a, 1922.

The load switch 90 includes a magnet coil 91 having one end connected with wire 63 and the other end with the frame 81 of the starting switch relay 80, and thus with the armature 83. The engagement ot' the armature 83 with the contact 88 will cause the winding 91 to be energized to attract an armature 92 into a position for connecting the wire 62 attached to the armature 92 with a contact 93 and a contact 94. Contact 91 is connected with wire 63 and the contact 93 is connected by wire 95 with the dynamo brush 96. As shown in Fig. 1, the shunt lield 15 is connected between the wires 95 and 77, and one end of the series field is connected with wire contacts 93 and 94; and as contact 97, insulatingly mounted on the armature 92, engages contacts 98 and 99. Contact 98 is connected by wire 100 with a terminal of the cranking cut-out 110. The contact 99 is connected by wire 101 with wire 63.

One end of the ignition coil primary 21 is connected by wire 102 with wire 89 and the other end is connected by wires 103 with timer 2 2, which in turn is connected by wire 104 with wire 75. y i

The cranking cut-out includes a base 111 which insulatingly supports a bimetallic thermostat blade 112 iixed at 113 and provided with latch hook 114`tor engagement with a latch lever 115 insulatingly supported by the base 111 and urged clockwise by a spring 116. Blade 112 is connected by wire 117 with contact 58 and is surrounded by a heating coil 118 connected with contact 57 and with a contact 119 adapted to be engaged by a contact 120 insulated from lever 115 and connected with wire 100. y lVire 75 is connected with lever 115.

Mode of operation. Normally, the armature 56 is out of engagement with-the contacts 57 and 58; the

armature 72 of the starting switch 70 is out of engagement with the contacts 7 3 and 74: the armature 92 of the load switch 90 is out of engagement with the contacts 93 and 94, and contact. 97 cbnn'ects contacts 98 and 99;`and the. armature 88 of the load switch relay 80 is out of engagement with contact 88.

When there is a demand for current in the lighting circuit includingr lamps 18 in excess of a certain amount, the winding 59 will receive current from the battery to `cause it to be energized to attract the armature 56 in position for connecting contacts'57 and 58.

The plant may be started automatically by the demand' for current by the battery 17. As

previously explained, when the battery is dis-v charged toa certain extent, the. contacts 42 and 44 will be closed to connect the winding 41 with the battery. vWhen this occurs, the armature 56 will be attracted to connect contacts 57 and 58. -Y f TheA closing of a switch in 19" of the power circuit will cause the winding 61 to be connected with the battery and the armature 56 to move into the position shown.

The closing of contacts 35 and 38 will connect coil 41 with the battery and cause armature 56 to be moved into the position shown.

Whenever the armature 56 connects the contacts 57 and 58,.,the magnet coil 71 of the starting switch 7() will be connected with the battery to the following circuit: battery 17, wire 49, meter 48, wire 50, wire 139, wire 188, armature 56, contact 58, wire 117,

thermostat 112, lever 115, wire 75, coil 71, wire 63, back to battery 17. The armature 72 is, therefore, moved to connect the wire 79 with contacts 73 and 74. The following cranking circuitis, therefore, established: battery 17, wire 49, meter 48, wire 50, magnet coil 86, wire 79, armature 7.2, contact 74. wire 77, dynamo brush 78, through the armature to dynamo brush 96, wire 95, series winding 16, wire 89, wire 63 back to battery 17. The

shunt field winding is also connected with the battery. The dynamo also operates as a compound motor to vcrank the engine. ln case the engine becomes self-operative within reasonable time, the cranking cut-out 110 will remain as shown in Fig. 1.

During the change of status of dynamo '11 from a motor to a generator, the current in the winding 86 will be reduced and then will reverse in direction. At a predetermined low value of current discharged from the battery through thewinding 86, the winding 87 will be able to attractthe armature 83 into position for engaging the contact 88. lVhen this occurs, the winding 91 will be venergized to move the armature92 into the position shown in Fig. 1. This will cause the series field 16 to be short-circuited and the status of the dynamo to be changed from' differential compound to simple shunt. Therefore, the voltage of the generator will suddenly be in-` creased. Movement ot armature 92 causes the generator to be connected with the wire 62 which leads tothe power circuit including the motors 19, and also breaks connection of the contacts 98 and 99 and. therefore, interrupts the circuit of the heating coil 118. In this system the connection of the generator with the power circuit is withheld until after the engine has become self-operative and the generator has attained a voltage sullicient 'for the generator to supply the needed current to the power circuit.

The cessation of demand in the power circuit, or decreaseA in demand for lighting current belowa certain amount will cause the armature 56 to be released provided the winding 41 is not energized at this time. However, if this winding 41 be energized by the closing of contacts 42 and 44, the plant will continue to operate until the battery has reached a. predetermined high state of charge. Also, if the winding 41 has been energized by the closing of contacts 35 and 88the engine will remain operative until a certain high, enginetemperature has been reached. When the contacts 57 and 58 are disconnected, the ignition circuit is interrupted .and also the circuit of the starting switch coil 71. Therefore, the engine will stop and the dynamo will be disconnected from the battery and all of the control mechanism restored to the normal condition referred to In case the engine does not become selfopera-tive within a. reasonable period lof till cranking, the thermostat blade 112 will bend upwardly to cause the interruption of the circuit of the starting switch coil 71, the ignition circuit and the circuit of the heating coil 118, thereby preventing further discharge of the battery to start the engine.

While the form of embodiment ot the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

That is claimed is as follows:

l. A power plant comprising, in combination, an internal-combustion engine, means for controlling the fuel mixture proportions oi the engine. means for starting the engine, and a thermostat in thermal relation to the engine for controlling both said means.

2. A power plant comprising, in combination, an internal-combustion engine, means for controlling the fuel mixture proportions of the engine, and apparatus for starting and stopping the engine and including a single thermostat in thermal relation to the engine for causing the engine to be started at a certain low engine temperature and to cause the fuel mixture to be relatively rich at starting, or causing the fuel mixture to become leaner as the engine temperature increases, and then for causing the engine to stop when the engine temperature increases to a certain degrec.

3. A power plant comprising, in combination, an internal-combustion engine, and a single temperature responsive means for controlling the engine fuel mixture proportions and for causing the engine to start and stop automatically in response to engine temperature.

4. A power plant comprising, in combination, an internal-combustion engine, means including a valve for controlling the engine fuel mixture proportions, apparatus for causing the engine to start and stop automatically and including an electric circuit. and circuitcontrolling switch, and a thermostat in thermal relation to t-he engine for causing the switch to move into one of its circuit-controlling positions to start the engine at a certain low engine temperature, and to operate said valve so that a rich fuel mixture will be provided for starting and so that the mixture will become leaner as the engine temperature increases, and then for causing the switch to move into another circuit-controlling position to stop the engine at a certain high temperature of the engine.

5. A power plant comprising, in combination, an internal-combustion engine, means for starting the engine, and a. single thermostat for varying the fuel mixture proportions ofthe engine in accordance with the temperature of the engine and for rendering the starting meansV operative when the temperature of the engine falls to a certain degree.

6. A power plant comprising, in con'ibination, an internal-combustion engine, and a single thermostat for varying the fuel mixture proportions of the engine and for rendering the engine inoperative when the temperature thereof increases to acertain degree.

In testimony whereof I hereto ailix my signature.

' FRANK F. STARR.

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