US3757756A - Automatic engine starting system - Google Patents

Abstract

A rotating, spark ignition, gas engine has a starter motor and an ignition magneto. A pneumatic logic system operated by gas responds to a starting impulse to rotate the engine by a gas driven starter until the magneto has an appreciable electrical output, whereupon starting and running gas are, under control of the pneumatic logic system, furnished the engine and the starter is decoupled. The pneumatic logic system discontinues the starting sequence unless the engine properly comes up to minimum running speed.

Description

United States Patent Owyoung et a].

[451 Sept. 11, 1973 Filed:

Assignee:

AUTOMATIC ENGINE STARTING SYSTEM Inventors: Sheldon Owyoung, Oakland;

Maurice H. Lowrey, Pleasanton, both of Calif.

De Laval Turbine California, Inc., Oakland, Calif.

June 21, 1972 Appl. No.: 264,948

[52] US. Cl 123/179 G, 123/179 F, 123/179 B,

290/38, 60/3914 [51] Int. Cl. F02n 17/00, F02n 17/06 [58] Field of Search 123/179 F, 179 G,

[56] References Cited UNITED STATES PATENTS 2,962,597 11/1973 Evans 123/179 B X 3,406,670 10/1968 Hines 123/139 R 3,664,123 5/1972 Zucca et al 123/179 F X 3,573,482 4/1971 Dexter et al.... 123/179 G X 3,587,228 6/1971 Clements..... 123/179 F X 2,741,086 4/1956 Machlanski 60/3914 Primary ExaminerAl Lawrence Smith Assistant ExaminerW. Rutledge, Jr. Attorney-Marcus Lothrop et al.

57 ABSTRACT 12' Claims, ZDrawing Figures 27 29 A c 1 START WW A a B 49 96 [f3- 48 98'- 57 GAS H5 #156 so PSI A42 '59 7 121 is "9 k A43 242 I46 SHUTDOWNS |44 B 221 W 1 l 248 2 B 218 2'9 lszu-H A93 |9| VENT FUEL GAS SUPPLY VENT I19 241 Sept. 11, 1973 United States Patent 1 Owyoung et al.

STARTER ITI AUTOMATIC ENGINE STARTING SYSTEM The invention relates primarily to the matter of automatically, even remotely, starting safely and surely an internal combustion engine, particularly such an engine of relatively large size such as a reciprocating piston, four-stroke cycle, spark-ignited and gas-fired rotary engine coupled to a load; for example, a gas compressor. Such engines are often installed in relatively remote locations without particular supervision, and while they often run for protracted periods after each start they also are dormant from time to time and must be readily started at any time and from any suitable point. Particularly in the environment of a fuel gas pumping plant, it is highly desirable to minimize the amount of electrical gear used in order to avoid danger of explosion or fire. It is also highly desirable that the engine starting be accomplished according to a predetermined program so that the engine can readily be started from its stopped condition, but only when all of the surrounding circumstances are appropriate. Should the engine be subject to a partial load during or shortly after starting, it is often desirable to have some provision for interrupting the starting cycle, should the engine, through some unforeseen circumstance, not start as it normally should.

There are various background considerations or desiderata to be observed in considering the starting of such an engine without an attendant and automatically. For example, it is important that the engine initially be cranked or rotated a number of revolutions with its ignition off and its fuel gas shut off. This is to purge any residual gas which might have remained in the engine after its last operation. Should this not be done, the residual gas may ignite or explode harmfully in the exhaust system, and particularly in the exhaust muffler, during the subsequent starting operation. That is, it is desirable to rotate the engine through sufficient cycles without inducing any new gas flow into the engine and without any spark ignition to pump atmospheric air through the engine to a sufficient extent to drive out ahead of it any accumulated or residual gas. The true starting cycle begins with an engine purged of gas and containing only atmospheric air.

In many engines the ignition timing is such that the ignition spark is initiated before the piston has quite arrived at its extended or top dead center position. Unless the starting inpulse is quite strong, unless the momentum of the engine rotary parts is sufficient in the forward starting direction, an early ignition may drive the engine in the reverse direction, thus inhibiting or precluding proper starting.

In engines deriving their ignition current from an engine-driven electric generator such as a magneto rather than from a separate source such as a battery of a known voltage, it is important that the magneto be rotated at a sufficient rate to ensure sufficient ignition voltage before the electrical current is supplied to the sparkplugs. At slow engine and magneto speeds the resulting magneto voltage, dependent upon speed, may be too low to afford a sufficient spark for proper ignition. When gas is the engine fuel it is important that the gas be available to the engine at or near the designed pressure so that the gas metering mechanism gives a proper mixture for appropriate starting.

It is highly likely that an engine in good repair and with normal automatic supervision of the required factors will unfailingly start. No particular fail-safe mechanism is usually needed. There is a remote possibility that, due to mechanical failure, tampering or the like, the engine may not start as programmed. In some commercial instances this remote possibility can be ignored and no provision made for it. Under other commercial circumstances it is advisable to have an overriding failsafe mechanism. Should the start sequence not develop properly and result in engine starting, the entire sequence is automatically cancelled.

Since in most instances the starter engine or motor (often a gas displacement device) is not designed to be normally connected to the engine, but is temporarily connected thereto only during the engine starting, it is important that the starter or cranking motor be promptly disconnected when the engine starts or shortly thereafter so that there is no damage to the starter and wear of the starting device is not excessive. Furthermore, the fuel supply must be so interrelated with the starting sequence that the relatively small supply of fuel required for starting and initial combustion is augmented at a desired rate so that the engine can, without starving or flooding, come up to its appropriate, governed speed under whatever load is imposed.

It is therefore an object of our invention to provide an automatic engine starting system that takes into account and satisfies all of the requirements set out hereinabove.

Another object of the invention is to provide an automatic engine starting system that operates without any electrical equipment except the magneto normally provided on the engine for ignition purposes.

A further object of the invention is to provide an automatic starting system that for the most part utilizes pneumatic logic elements preferably operated on the same gas that the engine itself utilizes for fuel.

Another object of the invention is to provide an automatic starting system that is generally an improvement over other systems heretofore available.

A further object of the invention is to provide an automatic engine starting system that is substantially foolproof and is fail-safe.

Other objects of the invention together with the foregoing are attained in the embodiment of the invention described in the accompanying description and illus trated in the accomapnying drawings, in which:

FIG. 1A is a diagrammatic showing of the left-hand portion of a schematic layout illustrating the automatic starting system of the invention; and

FIG. 1B is the right-hand diagram of this system, the entire diagram being readily discernible by placing the left-hand edge of FIG. 1B alongside the right-hand edge of FIG. IA to make a complete layout.

In a typical practical example, the engine 6 to be started is one connected to an appropriate load 7 of any suitable sort, such as a gas compressor. The engine is the usual rotary, reciprocating piston, internal combustion engine operating preferably on the four-stroke cycle, utilizing gas as a fuel and employing sparkplugs 8 for ignition. The engine is equipped with an enginedriven, electric generator such as a magneto 9 for furnishing electricity for ignition. The magneto primary is able to produce several hundred volts when the magneto speed is sufficient. The magneto primary voltage varies in a general way with the engine speed. The engine likewise is equipped with a standard speed and load governor 11. This does not take part in the starting cycle, although it does take control of the general operation of the engine. For turning the engine over initially from rest to get it started, there is provided a starter motor or engine 12 operated by gas under pressure, usually some of the gas that is also used as a fuel. Either included with the governor 11 or as a separate device, there is also provided a speed responsive unit 13 able to furnish a pneumatic signal at a predetermined engine speed, usually a mimimum idling or starting speed.

To provide the desired automatic starting function and to take care of various control, supervisory and safety features, there is utilized a pneumatic logic system of the sort shown in the copending application of Ray M. Bacchi entitled Automatic Control System filed Aug. 27, 1970 and bearing Ser. No. 67,540. In the Bacchi application there is a full explanation of the various pneumatic logic units disclosed and utilized herein, and there is shown an engine environment comparable to that discussed herein.

The penumatic logic units utilized can be activated by any appropriate pneumatic fluid, either atmospheric air, special gas or even the same gas that is used as a fuel in the engine.

In the present instance such a pneumatic supply, herein assumed to be fuel gas for convenience and referred to simply as gas, is derived under pressure from an appropriate source 16 and is furnished through a conduit 17 at approximately 60 psi to a group 18 of shut-down devices. These are illustrated diagrammatically and are sensors, as disclosed in the Bacchi application, that monitor various of the operating factors of the engine and sometimes of its connected load 7. For example, one of the sensors is activated when the engine is running, so that no superfluous and perhaps damaging starting sequence can be established under such a condition. Another sensor might have to do with the adequacy of lubrication in the engine or compressor. A third sensor might have to do with the presence of adequate and temperate cooling water. Other sensors may have to do with the presence of appropriate fuel and similar control factors deemed to be important. The various shut-downs are usually connected in a series fashion, so that if any of the monitored conditions for engine operation are not satisfactory, then such shut-downs do not afford a go" signal, but rather they prevent the transmission of operating gas through the conduit 17. If all of the control or shut-down sensors are in proper condition for engine starting, then gas pressure from the conduit 17 is made available in an extension conduit 19 connected to a terminal 21 of a pneumatic logic control board generally designated 22.

Within the terminal board the signalling gas from the terminal 21 arrives at a junction point 23 and from there flows in a branch path 24 to the B port of a notgate 26 and through the then-uninhibited not-gate to an outlet conduit 27 passing through a junction point 28 to an output terminal 29 identified as crank signal". The pressure from the terminal 29 is transmitted through a conduit 31 to a pressure chamber 32 (FIG. 18) effective to shift a control valve 33 against the urgency of a return spring 34 from the pressure position shown in FIG. 18 into the opposite, vent position. In the vent position of the valve 33, gas from the pressure supply 16 is conducted through a pipe 36 into a dead end or stop port 37 in the valve 33, and an atmospheric vent 38 is connected through a duct 39 to a conduit 41 extending through a junction point 42 to the actuator 43 of a cranking valve 44. At this vented stage there is no pressure within the conduit 41, and so none on the valve actuator 43, and hence a return spring 46 maintains the cranking valve 44 in the position shown in FIG. 1B and without activation.

When it is desired to initiate the automatic starting of the engine 6 after the system has been pressurized as indicated in part, then a starter control 47 is activated locally or remotely and this sends a pressure signal through a conduit 48 to a board input terminal 49. From there the signal travels in a conduit 51 to the C port of a set-reset unit 52. The signal emerges from the B port of the set-reset unit 52 and travels through a line 53 to enter the A port ofa memory unit 54. The B port of this unit is supplied with gas from the conduit 24 from ajunction point 56, while the output C port of the memory unit 54 is joined by a duct 57 through a junction point 58 to the A port of the not-gate 26. Receipt of the input signal at the A port of the not-gate 26 inhibits further signal travel from the B port to the C port of the not-gate 26 and through the conduits 27 and 31 vents the chamber 32.

With the pressure exhausted from the chamber 32, the spring 34 shifts the previously venting valve 33 into the supply position shown in FIG. 1B. In this position gas from the supply 16 flows through the conduit 36 and through the valve into the conduit 41, thus pressurizing the actuating chamber 43 of the cranking or relay valve 44 and shifting that valve to supply position against the urgency of the spring 46.

In the supply position of the valve 44, cranking gas is furnished through a conduit 61 past a junction point 62 and past a junction point 63 and then through a pressure regulator 64. The regulated gas travels through a duct 66 and through the shifted valve 44 into a pipe 67 and past a junction point 68 into a delay unit 69. The delay unit includes a restricting orifice 71 shunted by a backflow duct 72 in which a check valve 73 is disposed. This arrangement permits gas flow from left to right in FIG. IB at a very slow or restricted rate but allows gas flow from right to left at a fast rate.

Because of the restriction 71, there is substantial pressure of the signal at the junction point 68. This actuates a chamber 74 to shift a cranking motor engaging valve 76. Against the urgency of a spring 77, the valve is moved from its off position, as shown in FIG. 1B, into its on position. In this latter condition, cranking gas from the junction 63 flows through a connecting duct 78 to ajunction point 79, from whence the flow continues through a line 80 to the starter motor 12. This flow from the engaging valve 76 is only sufficient to cause the starter motor 12 to engage itself with the engine drive mechanism. It does not cause the cranking motor 12 actually to rotate the engine.

The restriction 71 produces some delay in gas flow through the restriction from the junction point 68 into a duct 81 leading through an accumulator 82, affording some further delay. Finally there is sufficient pressure buildup within an actuator 83 on a cranking motor valve 84, a predetermined time after the valve 76 has been actuated, to shift a cranking valve 84 from its off position, shown in FIG. 13, against a spring 86 and into an on position. Gas from the junction point 62 then travels through a conduit 87 and through the valve 84 into a conduit 88 leading to the junction point 79 and furnishes an adequate supply of cranking gas to the now-engaged starter 12 to rotate the starter motor under power so that the engine 6 is revolved at crank ing speed.

Since the initial signal from the unit 47 in the line 51 goes through the set-reset unit 52 and the memory unit 54, the cranking signal, upon occurrence, is automatically latched in, and while it does not require any par ticular duration of signal from the starting mechanism 47, it does continue until some subsequent event. This event can be the lapse of time. The starting signal can be automatically discontinued after a predetermined time; for example, a maximum period of seconds, in practice found to be adequate under all circumstances but not to be excessive.

For this reason, there is provided from the junction point 58 (FIG. 1A) a duct 91 extending to the A port of a timing unit 92, the C port of which is connected by line 93 to the A port of an or-gate 94. The C port of an accumulator 96 is joined at a point 97 to the duct 93. The C port of the or-gate is joined by a duct 98 to the A port of the set-reset unit 52. Thus the same signal at the point 58 that inhibits the not-gate 26 and initiates the cranking cycle just described likewise energizes the set-reset unit 52 and unlatches it. This occurs after a predetermined time established by the timer 92 and the accumulator 96; for example, a period of twenty seconds. Thus, from the initial starting impulse, the engine 6 is cranked for a period not to exceed twenty seconds.

During the initial interval when the starter motor 12 is revolving the engine 6 at av moderate rate, the grounded magneto 9 is likewise being rotated and furnishes an electrical output. The electricity so generated is carried from the magneto 9 through an electrical conductor 101 to a junction point 102, from which a lead 103 extends (through appropriate, standard ignition devices, not shown) ultimately to the sparkplug 8. The magneto primary voltage at relatively low engine cranking speeds is not sufficient to afford spark ignition, although as the engine speed picks up the magneto voltage becomes sufficient to produce an ignition spark.

During cranking, the low voltage current at the junction point 102 is likewise conducted through a lead 104 to a junction point 106, from which another lead 107 extends to a pressure switch 108. This switch includes a switch arm 109 when in closed position, as shown, establishing connection with a lead 111 to a solenoid 112 having a connector 1 13 extending to a ground 114. The solenoid 112 when so energized overcomes a spring 116 and shifts a signal valve 117 from shut to open position. Connected to the inlet of the valve 117 is a conduit 118 extending from the gas junction point 42. In the shut position of the valve shown, there is no communication beyond the valve from the conduit 118, but when the solenoid 112 is energized the valve is shifted and gas under pressure is transmitted through the valve 117 into a signal conduit 119.

The operation in this part of the system is that when the electrical output of the magneto 9 is very small, the valve 117 is spring closed, but when the engine is being cranked at a moderate rate, then sufficient electricity is generated in the magneto 9 to move the valve 117 to open position to furnish a gas pressure signal in the conduit 119. This pressure in the conduit 119 indicates that at least a minimum ignition current is available.

The pressure signal from the conduit 119 appears at a terminal 121 (FIG. 1A) on the board 22 and, through a connector 122, appears at the C port of a set-reset unit 123 after passing a junction point 124. From the B port of the set-reset unit 123 a conduit 126 extends to the A port of a memory unit 127. The B port of this memory unit is joined through a duct 128 to ajunction point 129 connected by a line 131 to the gas supply junction point 23. From the C port of the memory unit 127 flow is through a line 132 to the A port of an andgate 133. The B port of the and-gate 133 is joined to the junction point 129 by a duct 134, and the C port of the and-gate 133 is joined by a line 136 to a junction point 137 having a line 138 going to the B port ofa notgate 139. From the junction point 124 a conduit 141 extends to the A port of the not-gate 139, the C port thereof being connected to a junction point 142.

With this arrangement as so far described, a signal at the input port 121 latches the set-reset unit 123 into an on position, so that a supply of gas at the junction 129 is passed through the memory unit 127 and through the conduit 132 to the and-gate 133, from which flow is to the junction point 137. Flow could be from that point through the not-gate 139 to the junction point 142, except that the same signal at the junction point 121 through the line 141 puts an inhibition on the not-gate 139. At this time there can be no signal at the point 142. However, the junction point 137 is joined by a line 143 to a terminal 144 connected by a conduit 146 to the input side of a flow regulator 147 (FIG. 1B). Like the flow regulator 69, the flow regulator 147 includes a restricted orifice 148 to slow flow therethrough, the orifice being shunted by a line 149 including a check valve 151.

Flow from left to right in the figure may be at a rapid rate since the ball check 151 opens, permitting unrestricted flow. A

However, flow from right to left in the figure is greatly restricted since the check valve 151 closes and the orifice 148 acts as a limiter. There is thus a rapid signal from the conduit 146 that passes the regulator 147 and flows through a duct 152 to an ignition pressure switch 153. This switch is connected to the normally closed switch blade 109. The pressure signal in the conduit 152 indicates that ignition current is available. The pressure in the actuator of the switch 153 opens the blade 109, thus disconnecting the magneto from the solenoid 112.

This does two things. It reduces the electric load on the magneto and immediately affords increased voltage, which allows sparking to begin at the sparkplug 8. It also permits, since the solenoid is now quiescent, the spring 1 16 to shift the valve 1 17 and to vent the conduit 119 from the pressure source through the conduit 118. There is thus an immediate cessation of the pressure signal at the terminal 121. This is reflected through the junction 124 and the line 141 and removes the inhibition from the not-gate 139. correspondingly, the pressure signal from the and-gate 133, already available at the junction point 137, is now permitted to pass from the B port to the C port of the not-gate 139.

The signal is split at this point. Part of it extends from the junction point 142 through a conduit 156 to the A port of a timer 157, the C port of which is joined by a conduit 158 to the B port of the or-gate 94. The timer 157 has a time interval of approximately four seconds, for example. Thus, upon receipt of a signal at the junction 142, the timer 157 is started and after four seconds is effective to transmit a signal through the or-gate 94 to the set-reset unit 52, thus stopping the cranking signal, should this four-second interval cxpire prior to the expiration of thc twenty-second total cranking time permitted by the timer 92.

Another part of the signal distributed from the junction point 142 transmits pressure through an output terminal 159 and through a line 161 to ajunction point 162. From that junctIon point pressure goes through a line 163 to an actuator 164 capable of producing only a partial or minor opening of a main valve 166 normally pressed by a spring 167 into a closed position, as shown. The valve is interposed between a fuel gas supply source 168 connected thereto by a conduit 169 and a line 171 which extends to the gas equipment (not detailed) supplying fuel to the engine 6.

The signal in the line 163 energizes the actuator 164 to move the valve 166 against the spring 167 toward an open position, so that some fuel from the source 168 is supplied through the line 171 to the engine 6. However, the influence of the actuator 164 is able to move the valve 166 only slightly open, so that only sufficient gas is permitted to flow to the engine to permit it initially to fire at a cranking rate or slow speed. A large gas supply which might flood the engine cannot pass through the valve 166 so long as that valve is actuated solely by the actuator 164.

The signal that appears at the junction 162 not only opens the valve 166 slightly for starting combustion in the engine 6, but also has an additional function to set the gas supply system for full-scale operation.

At the very beginning of the starting operation when a signal appears at the junction point 28 (FIG. 1A) and is sent through the line 31 to engage and rotate the cranking motor 12, part of the signal at the point 28 is also conducted through a connector 173 that goes to the A port of an and-gate 174. The signal leaves that gate through the C port into a conductor 176 extending to a junction point 177 from which a conductor 178 takes the signal to the A port of a timing unit 179. From the C port of the timer 179 a conductor 18] extends to the A port of an and-gate 182. The B port of the andgate 174 is connected by a line 183 to the junction point 142, while the B port of the and-gate 182 is connected by a line 184 to the junction point 23.

When the initial starting signal arrives at the junction point 28, the and-gate 174 is partially conditioned and is fully conditioned when the starting fuel gas signal arrives at the point 142. An emitted signal then appears at the junction point 177 and at the timer 179. This has a time period of five seconds, for example. After five seconds the timer signals through the connector 181 to the A port of the and-gate 182. The B port thereof being already connected to the junction point 23, the signal from the timer 179 activates the and-gate 182 through its C port to supply a signal through a line 186 to an output terminal 187. A conduit 188 carries the signal to a junction 189.

From the junction 189 flow is to a pressure controller 191 like the controllers 69 and 147-. The controller 191 contains a restricting orifice 192 and shunting that a check val 7e 193. Flow from the top down in FIG. 1A is relatively slow and is regulated by the choke of the orifice 192, but return flow is rapidly effective to lift the check valve 193. On the downstream side of the controller 191 a conduit 194 extends to a junction point 196, to which an accumulator 197 is joined. The result of this is that there is a slow buildup of pressure at the junction point 196 to the 60 psi operating pressure of the system.

It is usually desired to achieve a buildup of a major fraction of this full system pressure in much less time than it takes with the restriction 192 and the accumulator 197. Consequently, shunting the junction points 189 and 196 there is provided a conduit 201 including a pressure regulator 202 in series with a check valve 203 opening in a direction toward the junction point 196. During the relatively long time it would take pressure passing through the orifice 192 to buildup to maximum, the pressure regulator 202 and check valve 203 permit rapid passage of gas up to a fixed pressure slightly below the maximum system pressure. The system pressure is achieved through the orifice 192 slightly thereafter.

Use of pressure at the junction point 196 is made through a valve 204 affording an interlock. Normally the valve is in an off position, as shown, maintained by a spring 206. When a pressure signal appears at the junction 162, a branch line 207 transmits the same pressure to an actuator 208, which immediately shifts the valve 204 into a communicating position. A line 209 sends the pressure at the junction 196 to an actuator 211 also connected to the fuel gas valve 166. The actuator 211, unlike the actuator 164, is capable of fully opening the fuel gas valve 166. Full valve opening does not take place immediately there is a signal from the and-gate 182 appearing at the point 189. The buildup to system pressure is relatively slow, even though the valve 204 is immediately opened, because of the restriction due to the orifice 192. The actuator 211, therefore, gradually moves the valve 166 from a slightly open or idle, starting position to a full open operating position. The rate of gas valve opening is so regulated that at no time is the engine either starved for fuel or flooded with fuel.

With the arrangement operating as described, therefore, the engine has been started and is operating fully, with future engine operating conditions being controlled by the governor 11 in the usual way and without regard to this starting mechanism. In many installations that alone is entirely adequate, and while the starting of engines of this type is extremely reliable and can generally and from the practical sense be counted upon, there are instances wherein a failure might be possible or in which it is desired to be extremely cautious and safe. Under such circumstances a further check is made to make certain that the engine is actually operating at appropriate speed before the starting program is dismissed.

At the time a signal appears at the junction 177 (FIG. 1A), as part of the signal that starts pressure in the line 186 affording fuel gas for full engine running, a part of the same signal at the junction 177 is transmitted through a conductor 216 to the B port of a not-gate 217, the C port of which is joined by a duct 218 to an output terminal 219. A line 221 connects the terminal 219 to a junction point 222. From this point a line 223 extends to a pressure cell 224 operating the normally open blade 226 of an electric switch 227. This has an electrical connector 228 joined to the point 106, and thus receives electricity from the primary of the magneto 9. From the switch 227 a connector 229 joins to a solenoid 231 connected by a lead 232 through a variable resistor 233 having a conductor 234 leading to ground. A circuit with the magneto is completed when the switch blade 226 is closed.

When the switch blade 226 is open, the solenoid 231 is inactive, so that a spring 236 maintains a signal valve 237 in the position shown in FIG. 1B. This valve 237 is connected to the junction 222 by a conduit 238 in which a restrictive orifice 239 is interposed. The outlet of the valve 237 is through a pipe 241 extending to a terminal 242 (FIG. 1A) on the board 22. The terminal 242 is joined through a conductor 243 to the A port of the set-reset unit 123. What happens is that there is a signal at the junction point 177 (FIG. 1A) that travels through the not-gate 217 in its normally uninhibited condition, that signal arrives at the junction point 222 and through the cell 224 actuates the switch blade 226 to close the switch 227. That operation electrically connects the magneto through the solenoid 231 and the resistor 233 to ground, thus energizing the solenoid and putting some electrical load on the magneto. This is not a great electrical load, however, and although there is a corresponding drop in voltage it is not enough to interfere with satisfactory spark ignition of the engine.

The energized solenoid 231 shifts the valve 237 and blocks the signal in the line 238 from going beyond the valve 237, electrically held in its block position against the spring 236. Should the engine for any reason not come up to a proper initialspeed, the output of the magneto 9 is correspondingly low and is insufficient to energize the solenoid 231. The particular current value corresponding to a chosen engine speed is adjustable by varying the resistor 233. In the event of deficient speed and current, the valve 237 is not shifted from the position shown and, with some delay due to the restriction 239, permits the signal in the line 238 to travel through the conductor 241 and the terminal 242 to the A port of the set-reset unit 123, thus shifting its condition and interrupting the operation of the starting cycle by shutting off all fuel gas through the terminal 159, and the junction 162.

On the engine 6 is a speed sensing unit 13 as previously described and in detail as shown in the aboveidentified Bacchi application. This speed sensing device 13 does not afford any signal whatsoever until the engine 6 is operating at a predetermined speed, which presupposes appropriate starting or idling combustion and ability to continue to higher speeds and loads, if de sired. When the engine after starting achieves a predetermined, arbitrary speed, the speed unit 13 puts out a signal in a conduit 246 to a terminal 247 on the board 22 indicating that the engine has attained an arbitrary speed so that the starting mechanism can relinquish its role and the governor 11 can properly take over. The signal at the terminal 247 is transmitted through a conduit 248 to the A port of the not-gate 217. If the notgate 217 is not inhibited by an appropriate engine speed signal, there would be a continuing unnecessary load imposed on the magneto by the solenoid 231. Such load might prevent adequate ignition at high engine loads. But, on the contrary, if the engine is up to its appropriate governed speed, this proves that the start was successful, and so the speed unit 13 provides a signal at the terminal 247 which inhibits the not-gate 217 and vents the now-unneeded signal from the C port of the not-gate 217 from the junction 222. Consequently, the solenoid 231 is disconnected from the magneto primary by the switch 227 and, also, the signal it might have transmitted is vented.

What is claimed is:

1. An automatic starting system for a rotating engine having a starting motor and having an electric generator rotated by said engine comprising means responsive to a starting impulse for energizing said starting motor to rotate said engine, means for supplying fuel to said engine, a valve for controlling said fuel supplying means, and means responsive to the production by said generator of electricity above a predetermined value for opening said valve.

2. An automatic starting system as in claim 1 in which said engine employs spark ignition and said predetermined value is sufficient toenergize said spark ignition.

3. An automatic starting system as in claim 1 in which said valve has a starting position and a running position and in which said responsive means opens said valve to said starting position in response to said predetermined value and opens said valve to said running position a predetermined time thereafter.

4. An automatic starting system as in claim 3 including means for controlling the rate of opening of said valve between said starting position and said running position.

5. An automatic starting system as in claim 1 including means effective upon receipt of said starting impulse for maintaining the operation of said starting motor energizing means for a predetermined maximum time.

6. An automatic starting system as in claim 1 including means effective upon attainment of electricity production above said predetermined value for interrupting the operation of said starting motor energizing means a predetermined time thereafter.

7. An automatic starting system as in claim 1 including means for inhibiting the opening of said valve.

8. An automatic starting system as in claim 7 including means for delaying the operation of said inhibiting means.

9. An automatic starting system as in claim 7 including means responsive to the rotating speed of said engine above a predetermined minimum speed for preventing the operation of said inhibiting means.

10. An automatic starting system as in claim 1 in which said means responsive to a starting impulse ineludes pneumatic logic units.

11. An automatic starting system as in claim 10 in which said fuel is gas and said pneumatic logic elements are operated by said gas.

12. An automatic starting system as in claim 1 in which said electric generator is a spark ignition magneto for said engine.

n: m t

Claims (12)

1. An automatic starting system for a rotating engine having a starting motor and having an electric generator rotated by said engine comprising means responsive to a starting impulse for energizing said starting motor to rotate said engine, means for supplying fuel to said engine, a valve for controlling said fuel supplying means, and means responsive to the production by said generator of electricity above a predetermined value for opening said valve.

2. An automatic starting system as in claim 1 in which said engine employs spark ignition and said predetermined value is sufficient to energize said spark ignition.

3. An automatic starting system as in claim 1 in which said valve has a starting position and a running position and in which said responsive means opens said valve to said starting position in response to said predetermined value and opens said valve to said running position a predetermined time thereafter.

4. An automatic starting system as in claim 3 including means for controlling the rate of opening of said valve between said starting position and said running position.

5. An automatic starting system as in claim 1 including means effective upon receipt of said starting impulse for maintaining the operation of said starting motor energizing means for a predetermined maximum time.

6. An automatic starting system as in claim 1 including means effective upon attainment of electricity production above said predetermined value for interrupting the operation of said starting motor energizing means a predetermined time thereafter.

7. An automatic starting system as in claim 1 including means for inhibiting the opening of said valve.

8. An automatic starting system as in claim 7 including means for delaying the operation of said inhibiting means.

9. An automatic starting system as in claim 7 including means responsive to the rotating speed of said engine above a predetermined minimum speed for preventing the operation of said inhibiting means.

10. An automatic starting system as in claim 1 in which said means responsive to a starting impulse includes pneumatic logic units.

11. An automatic starting system as in claim 10 in which said fuel is gas and said pneumatic logic elements are operated by said gas.

12. An automatic starting system as in claim 1 in which said electric generator is a spark ignition magneto for said engine.

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