US3308305A - Automatic starter for prime movers - Google Patents

Description

March 7, 1967 A. c. MORSE, JR 3,308,305

AUTOMATIC STARTER FOR PRIME MOVERS Filed Aug. 25, 1964 2 Sheets-Sheet 1 INVENTOR. Hg- Ari/Yul C. Morse Jr:

United States Patent C) 3,308,305 AUTOMATIC STARTER FOR PRIME MOVERS Arthur C. Morse, Jr., Topeka, Kans., assignor to Electronic Development Mfg. Corp., Holton, Kaus., a corporation of Iowa Filed Aug. 25, 1964, Ser. No. 391,948 8 Claims. (Cl. 29038) This invention relates to improvements in apparatus for automatically starting prime movers, particularly diesel engines.

Many systems have heretofore been proposed for automatically starting internal combustion engines. The apparatuses involved, however, have presented numerous disadvantages including unreliability, cumbersome size, and needless complexity. Additionally, in the case of engine starters for motor vehicles, previous automatic starter systems have not provided a flexible arrangement for preventing excessive discharge of the vehicle battery if the engine fails to start.

Although adapted for a wide number of applications, automatic starters are particularly useful in the trucking industry where large transport vehicles are employed. Such vehicles are generally diesel-powered and, in cold climates, require periodic starting to maintain proper engine block temperature. If the temperature of a diesel engine is permitted to fall to a low value, starting is quite difiicult and time-consuming. While the driver of the vehicle is resting over night, the temperature of the engine block of the vehicle parked outside will easily drop to a temperature preventing ready starting during wintertime in the northern sections of the United States and in Canada.

It has been found that optimum engine heat may be maintained if the engine is periodically started during the night and allowed to operate for a short period. In the case of diesel engines, hourly starting is preferable, the motor being allowed to run for approximately 20 minutes. For gasoline engines, however, restarting at intervals of approximately three hours is usually sufiicient. Manifestly, the starting of diesels is a more severe problem since this type of engine relies strictly on internal compression heat for ignition.

It is requisite that means be provided to limit the cranking time of the engine or excessive discharge of the vehicle battery will occur. If the engine fails to start during one attempt, it is evident that starting will likely not occur during a subsequent attempt. Therefore, additional current drain would be prevented if the automatic starting apparatus were not allowed to again attempt engine starting after a failure occurs.

It is, therefore, the primary object of this invention to provide a flexible automatic starter for prime movers which will eliminate the excessive drain on the power source in the event that the prime mover fails to start.

Another important object of the instant invention is to provide improved arrangements of high reliability for intermittently cranking the prime mover during the starting period.

Still another important object of the instant invention is to provide automatic starting circuitry of flexible design adaptable for use with both gasoline and diesel vehicle engines, and also gasoline or jet aircraft engines.

Other objects will become apparent as the following description proceeds.

In the drawings:

FIGURE 1 is an electrical schematic diagram of one embodiment of the apparatus;

FIG. 2 is an electrical schematic diagram of another embodiment of the apparatus;

FIG. 3 is an electrical schematic diagram of still another embodiment of the apparatus;

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FIG. 4 is an electrical schematic diagram of circuitry for modifying either of the embodiments of FIGS. 1-3 for use in the starting of diesel engines having fuel cutoff solenoids; and

FIG. 5 is an electrical schematic diagram showing an alternative arrangement for controlling operation of the starting apparatus.

Referring to FIGURE 1, apparatus is there shown including a timer 10, a latch relay 12, a normally closed time delay tube 14, a single-pole, double-throw time delay tube 16, a normally open time delay tube 18 and a relay 20. Relay 20 has a coil 20a and a pair of switches 20b and 20c, the former being normally open while the latter is normally closed. The movable poles of the switches are connected by line 22 to a terminal 24 which is adapted for coupling with a direct current power source (no-t shown). A line 26 connects the stationary contact of switch 20b with a starter solenoid 28 through a normally closed vacuum switch or oil pressure switch 30. Line 32 is used to connect the stationary contact of switch 200 with vehicle accessories such as the heater, line 32 having a normally open vacuum dashpot operated switch or oil pressure switch 34 connected in series therewith. It should be understood that the ground notation is used to indicate the other terminal of the power source of opposite polarity to terminal 24.

Timer 10 is a conventional clock control device for closing an electric circuit at predetermined times. The circuit here involved is from terminal 36 and along lead 38 through timer 10 to junction point 40. Terminal 3-6 is adapted to be connected to the same terminal of a power source as terminal 24.

Latch relay '12 includes a reset coil 42, a pair of normally closed contacts 44', a latch coil 46, a pair of normally open contacts 48, and a conventional latching arrangement 50. Latch relay 12 is of the single-pole, doublethrow type, the latch arrangement 50 being illustrated schematically only.

Time delay tube 18 comprises a heater element 52 and a pair of normally open contacts 54. The left-hand contact 54, as viewed in FIG. 1, is interconnected with coil 46 by lead 56. Theother contact 54 and one electrical side of heater 52 are connected by lead 58 to junction point 40. This junction point, in turn, is connected to the left-hand contact 44 by lead 60'. A normally closed vacuum or oil pressure switch 62 is connected in series with lead 58.

A manually operable reset switch 64 is connected in series with a lead 66 which interconnects coil 42 with lead 38 and terminal 36. A lead 68 bypasses switch 64, connecting one of the contacts 48 directly with lead 66, lead 38, and terminal 36. An incandescent lamp 70 is connected between ground and the other contact 48. It should be noted that a line 72 extends from junction point 40 and may be used to energize the ignition coil of a gasoline engine or the solenoid of a fuel supply valve of a diesel engine. A diode 73 is interposed in series with line 72 to block current flow from the power source to junction point 40 when the engine is started in the conventional manner.

The remaining components of FIG. 1, delay tubes 14 and 16, are interposed between the right-hand contact 44 and relay coil 26a. Tube 14 comprises a heater 74 and a pair of normally closed contacts 76, the left-hand contact 76 and one electrical side of heater 74 being connected with the right-hand contact 44 by lead 78. Tube 16 has a heater 80 and three contacts 82, 84 and 86, contacts 82 and 86 being fixed, while contact 84 is movable. Thus, the contact arrangement of tube 16 is of the single pole, double-throw type, the movable pole or contact 84 being connected with the right-hand contact 76 by lead 88. Contact 82 and one electrical side of 3 heater 80 are interconnected, contact 86 being connected by lead 90 to relay coil 2011. It should be understood that the return connections for the power circuits to solenoid 28, relay coil a, coils 42 and 46, and heaters 52, 74 and 80 are designated by the ground symbol.

Before proceeding with a description of the circuitry shown in the remaining figures, it is instructive to first discuss the operation of the FIG. 1 embodiment. The circuit of FIG. 1 has been described as a starting circuit for the engine of a motor vehicle, but it should be understood that the same is equally useful in the starting of stationary prime movers, either gasoline or diesel, or in the starting of aircraft engines. In the case of jet aircraft engines, the starting solenoid 28 would necessarily be replaced by the jet engine igniter.

When the apparatus is employed as an engine starter for a motor vehicle, the size of the components makes it a compact package capable of being mounted beneath the dashboard. In this manner, timer 10 is readily accessible and may be adjusted or set as desired. Terminals 24 and 36 may be connected with one electrical side of the vehicle battery, the return path for the current being through the vehicle chassis.

Other necessary connections include the connecting of the apparatus to the starter solenoid 28 by line 26, the

- heater or other accessories to be operated by line 32,

and the ignition system or fuel solenoid by line 72. It should be understood that line 72 would serve as a bypass around the normal, key-operated ignition switch when the starter circuitry is used on a vehicle having a gasolinepowered engine, but would energize the fuel solenoid in the case of diesel-powered vehicles. Furthermore, it should be noted that some diesel engines do not use a solenoid valve for supplying fuel to the cylinders but, instead, automatically pump fuel from the supply during cranking. In using the apparatus with diesel engines so equipped, line 72 would be eliminated and circuitry added to the apparatus to operate the solenoid valve which is employed with diesels of this type for cutting off the fuel supply when it is desired to stop the engine. Such additional circuitry appears in FIG. 4 and will be described hereinafter.

As another alternative, line 32 to the accessories may be omitted if heater operation is not desired while the engine is being operated. Line 32, and the normally open switch 34 coupled therein, would normally be omitted when the apparatus is used in the starting of diesel engine, since the engine would be maintained in at least a semi-heated state at all times. Thus, heat for the cab of the vehicle would be readily available when desired without excessive warm-up.

Each of the normally closed switches and 62 may comprise a conventional vacuum switch utilizing a pneumatic piston and cylinder assembly, when the starting apparatus is employed with gasoline engines. Since normally open vacuum switches of this type are presently not readily available commercially, the normally open switch 34 may consist of a unit comprising a vacuum dashpot operably coupled with a movable pole which is normally disengaged from an associated contact. The dashpot and cylinders are operably coupled with the intake manifold of the engine so as to be responsive to starting of the engine. Manifestly, when starting occurs, the pressure within the manifold is reduced below atmospheric pressure causing operation of the switches in a manner well known in the art. In diesel engine applications, these pressure-responsive devices are replaced by oil pressure sensitive switches which are responsive to the presence or lack of oil pressure in the lubrication lines of the diesel engine. Here again, engine operation establishes pressure in the lines causing operation of the switches to close or open the same as the case may be.

, In operation, timer It is set to close the electric circuit along lead 38 at the desired times. As discussed hereinabove, this would normally be once every hour for a period of approximately '20 minutes in the case of diesel engines, and once every 3 hours for a period of approximately 20 minutes in the case of gasoline-powered engines. At the desired time, the normally open switch of timer 1t) closes and current is made available to the heater 74 of tube 14 by way of a circuit through junction point 40, lead 60, closed contacts 44, and lead 78.

Tube 14 is a thermal relay which, after heater 74 is energized for a given time, will open its contacts 76 and maintain the same in open condition until subsequent cooling of heater 74. Tube 14 limits the period of time that the apparatus will intermittently crank the engine and, for this purpose, a thermal relay tube having a delay time of approximately 45 seconds is preferred.

During the 45 second interval prior to opening of contacts 76, current flows along lead 88 to contact 84 of tube 16, and thence through contact 82 to heater 80. Tube 16 is also a thermal relay but is of the single-pole, of heater 88 for a selected time (preferably approximately 5 seconds) causes the movable contact 84 to shift into engagement with stationary contact 86, thereby routing current from lead 88 through lead 90 to relay coil 20a. For a tube 16 having approximately a 5 second heating time, contact 84 will remain in engagement with contact 86 for a somewhat longer period, approximately 7 to 10 seconds, depending on tube design.

From the foregoing it is evident that relay coil 20 will be alternately energized and de-energized during the 45 second period prior to opening of contacts 76. When the relay is energized, a power circuit is created from terminal 24 along line 22 to the now closed switch 20b, and hence along line 26 to the starter solenoid 28 through the normally closed switch 30. Manifestly, this effects cranking of the engine, such cranking continuing intermittently until starting is effected, whereupon switch 30 opens under the effect of vacuum in the intake manifold or increase in oil pressure to break the power circuit to the starter solenoid. Starting of the engine should occur prior to the expiration of the 45 second period, in which case relay 20 will continue to operate but will be ineffective since switch 30 will now be open. After the 45 seconds has elapsed and contacts 76 open, the relay stays in its normal condition an shown, and power is made available to the accessories if desired. This circuit is: created from terminal 24, through line 22 to switch 200, and along line 32 to the accessories through the now closed manifold pressure or oil pressure responsive switch 34.

During the time that relay 20 is being pulsed by the action of relay tube 16, it should be noted that power is continuously made available to the ignition coil or fuel supply solenoid by way of a circuit from terminal 36, along lead 38 to junction point 40, and then along line 72 to the ignition system or solenoid. Current for the pulsing and timing apparatus described above, however, fiows through the normally closed contacts of the latch relay 12. Thus, operation of the pulsing circuitry is controllable by the latch relay which functions in a manner to be now described in the event that the engine fails to start.

From junction point 40, a circuit is made to the heater 52 of relay tube 18 by way of lead 58, the latter having a normally closed vacuum or oil pressure switch 62 interposed in series therewith. Thus, heater 52 is energized immediately upon operation of the internal switch of timer 10, the heating time of tube 18 being equal to that of tube 14, or 45 seconds in the instant example. The contacts 54 of this tube are normally open so that, at the end of the 45 second interval, contacts 54 will close to effect energization of relay coil 46 by way of lead 56, the latter forming a control connection for latch relay 12.

Since the engine responsive switch 62 is normally closed, energization of relay coil 46 will not occur if engine starting is effected prior to the expiration of the 45 second period. However, if the engine fails to start,

switch 62 remains closed and coil 46 is energized, thereby closing contacts 48 and opening contacts 44. This breaks power circuit to the relay pulsing circuitry and maintains this circuit open due to the action of the latch arrangement 50. Thus, subsequent opening of the switch of timer and re-closing thereof at a later time will have no effect on starter operation since contacts 44 will be locked open. This positively prevents continued cranking of the engine which would only serve to discharge the vehicle battery, since the engine is not likely to start at a later time if it fails to start earlier. This is especially important when the apparatus is being utilized to periodically start a truck motor while the driver is resting over night since by morning battery drain would likely be so excessive that selflstarting would be impossible. As a matter of interest, in the starting of diesel engines, ap-

proximately 17 minutes running time is required to replace the charge lost in the battery during one starting operation.

The incandescent lamp 70 is preferably mounted where it may be readily viewed by the driver since illumination of this lamp indicates that the latch relay 12 has operated and that the vehicle engine has failed to start. When this is seen by the driver and it is desired to return the apparatus to normal, reset switch 64 is momentarily closed thereby energizing coil 42 to return the contacts 44 and 48 to their normal positions as shown. It should be understood that a variety of conventional and commerically available latch relays are suitable for use with the instant invention; therefore, the structural details of relay 12 will not be discussed in this specification.

Referring to FIG. 2, it may be seen that a number of components there shown are identical to the components illustrated in FIG. 1, like reference characters denoting components of identical structure and function. The sole difference between FIG. 2 and FIG. 1 is in the means employed to pulse the relay coil a. In the FIG. 2 embodiment, current flows from junction point 40, upon operation of timer 10, along lead 60 to contacts 44, along lead 78 to contacts 76, and then through lead 92 to alow r.p.m. electric motor 94.

The output shaft 96 of motor 94 has a cam 98 rigidly aflixed thereto, cam 98 serving to close and then release a normally open cam switch 100. A lead 102 interconnects lead 92 with relay coil 20a through cam switch 100; thus, intermittent opening and closing of switch 100 by came 98 pulses relay coil 20a to repeatedly shift switches 20b and 20a in the same manner as described above for FIG. 1. Cam 98 is configured in accordance with the speed of rotation of shaft 96 to open and close switch 100 at the desired time intervals.

With reference to FIG. 3, the same components common to FIGS. 1 and 2 are also there shown, the only difference between FIG. 3 and FIG. 1 again being in the means utilized to pulse the relay coil 20a. This means includes a unijunction transistor oscillator 104 having an emitter 104a and bases 10412 and 104a, and a PNP amplifier 106 having an emitter 106a, a base 106b, and a collector 1060. A capacitor 108 interconnects emitter 104a and base 106b, a pair of resistors 110 and 112 being connected in -a series loop with capacitor 108. A lead 114 connects the common ends of resistors 110 and 112 with base 104]).

Relay coil 20a is coupled in the collector circuit of transistor 106 by leads 116 and 118, the latter lead joining with lead 114 at the common point of resistors 110 and 112. The pulsing circuitry is switched off by the action of contacts 76 as in the circuits of FIGS. 1 and 2, interconnection of contacts 76 and the pulsing circuit being effected by a lead 120 coupled with the base 1041) of the unijunction transistor 104. Base 1040 and emitter 106a are maintained at ground potential.

In the operation of the transistor circuitry, the unijunction transistor 104 oscillates, the length of time for the o cycle (coil 28 de-energized) of the oscillation being determined by the value of resistor 112. The length of the cranking interval or on cycle of the startersolenoid 28 is determined by the value of resistor 110. A pulse is delivered from transistor 104 during the on cycle, the pulse being amplified by transistor 106 and then applied to relay coil 20a through its collector circuit.

An arrangement is shown in FIG. 4 for use in the starting of diesel engines which utilize a solenoid valve as a fuel cutoff means. As discussed hereinabove, line 72 is no longer needed since such engines pump fuel from the supply upon cranking thereof. A timer 122 is shown in FIG. 4 having a pair of switching terminals 124 and 126, the latter terminal being connected to a switching circuit comprising a delay relay tube 128 and an electromechanical relay 130. Timer 122 is connected in either of the circuits of FIGS. 1, 2 and 3 substituting timer 122 for timer 10 and connecting lead 38 thereto in the manner shown. Thus, engagement of the timer switch element with switching terminal 124 corresponds to the on position of the timer and energizes the pulsing circuitry for relay 20. At the close of the running period for the engine, the internal switch of timer 122 closes a circuit through terminal 126 as shown to energize heater 132 of tube 128. This tube has a pair of normally closed contacts 134 which open after a preselected time period, preferably approximately 45 seconds. Before the contacts open, coil a of relay 130 is energized, closing its associated normally open switch 13011. This completes a circuit from lead 136, which may be connected with terminal 36, through switch 13% to the solenoid 138 of a solenoid-operated fuel cutoff valve 140. After 45 seconds of operation, the motor has ceased running and contacts 134 open to permit restarting of the motor at a later time when time 122 once again closes the circuit through lead 38.

FIG. 5 shows another alternative arrangement for use in place of timer 10. A temperature responsive switch 142 is shown operably associated with a bimetallic strip 144 which is in thermal contact with the engine (not shown). The bimetallic strip 144 is arranged to maintain switch 142 open when the engine heat is above a predetermined level. However, when the engine heat falls below this level, switch 142 closes, energizing the coil 146a of an electromechanical relay 146. This, in turn, closes a normally open relay switch 1461; to complete the circuit through lead 38 and energize the motor starting circuitry.

It will be appreciated, of course, that in the modification of FIG. 5, the apparatus is no longer time-responsive but is, instead, strictly temperature-responsive. This modification has application in certain instances where absolute temperature control of the engine is the primary consideration rather than the interval of running time thereof or the degree of battery drain.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. For use with a prime mover provided with electrically responsive starting means, apparatus for automatically intermittently energizing the starting means and for preventing subsequent operation thereof by the apparatus in the event that the prime mover fails to start, said apparatus including:

terminal means adapted for coupling with a source of electrical energy;

a power circuit coupled with said terminal means and adapted for coupling with said starting means for supplying current to the latter;

electrically responsive switching means coupled in said power circuit and having a first operational state for permitting current flow therein and a second, normal operational state preventing said flow;

circuit means intercoupling said switching means and said terminal means, and including a switching device for controlling operation of said circuit means, and means for repeatedly changing the operational state Z of said switching means in response to the operation of said circuit means, said switching device having a closed position for permitting current flow in said circuit means to place the same in operation, and an open position preventing current flow therein; control means coupled with said circuit means for rendering the latter inoperative, independently of the action of said switching device, after a predetermined time interval of operation of the circuit means, and including resettable switching structure for preventing further operation thereof by said switching device upon expiration of said interval; and means responsive to operation of said prime mover and coupled with said control means for rendering the latter inoperative upon starting of the prime mover, whereby to prevent operation of the control means if the prime mover starts within said time interval; said circuit means further including time delay means, normally permitting operation of said state changing means, for disabling the latter in response to current flow in the circuit means for a preselected period of time substantially equal to said predetermined time interval, said time delay means returning to its normal condition in response to operation of said switching device to place the latter in the open position thereof, whereby subsequent closing of the switching device again renders the statechanging means operable if starting of the prime mover has previously been effected prior to the expiration of said predetermined time interval.

2. The invention of claim 1, wherein said switching structure includes a latch relay having a relay coil, a pair of normally closed contacts movable to an open position in response to energization of said coil and coupled in series with said circuit, and means releasably maintaining said contacts in said open position upon movement thereto, said control means further including means coupled with said coil for applying excitation thereto in response to operation of the circuit means for said time interval.

3. The invention of claim 1, wherein said prime mover is provided with electrically responsive fuel cutoff means, and wherein is provided a switching circuit adapted to be coupled with said fuel cutoff means, said switching device being coupled with said switching circuit for controlling the latter to effect energization of the fuel cutoff means upon operation of the switching device to render the circuit means inoperative, said switching circuit including time delay means responsive to current flow therein for interrupting the switching circuit after a predetermined period of time, whereby the fuel cutoff means is energized for said period of time to cease operation of the prime mover.

4. The invention of claim I, wherein said switching device comprises timer means for rendering said circuit means operative at preselected times spaced apart by periods determined by the operating characteristics of the prime mover, whereby the latter is intermittently started as long as the circuit means is never operated longer than said predetermined time interval.

5. For use with a prime mover provided with electrically responsive starting means, apparatus for automatically intermittently energizing the starting means and for preventing subsequent operation thereof by the apparatus in the event that the prime mover fails to start, said apparat'us including:

terminal means adapted for coupling with a source of electrical energy;

a power circuit coupled with said terminal means and adapted for coupling with said starting means for supplying current to the latter;

electrically responsive switching means coupled in said power circuit and having a first operational state for permitting current flow therein and a second, normal operational state preventing said flow;

a cam switch;

a cam operably associated with said cam switch;

electrically responsive means coupled with said cam for driving the latter to intermittently operate the cam switch;

first circuit means coupling said drive means with said terminal means for supplying electrical energy to the drive means, said first circuit means including a switching device for controlling current flow therein;

second circuit means coupling said cam switch in series between said first circuit means and said switching means whereby, upon operation of the drive means, the operational state of the switching means is repeatedly changed;

control means coupled with said first circuit means for rendering the latter inoperative, independently of the action of said switching device, after a predetermined time interval of current flow therein, and including resettable switching structure for preventing further operation of the first circuit means by said switching device upon expiration of said interval; and

means responsive to operation of said prime mover and coupled with said control means for rendering the latter inoperative upon starting of the prime mover, whereby to prevent operation of the control means if the prime mover starts Within said time interval;

said first circuit means further including time delay means, normally permitting operation of said drive means, for disabling the latter in response to current flow in the first circuit means for a preselected period of time substantially equal to said predetermined time interval, said time delay means returning to its normal condition in response to operation of said switching device to place the latter in the open position thereof, whereby subsequent closing of the switching device again renders the drive means operable if starting of the prime mover has previously been effected prior to the expiration of said predetermined time interval.

6. For use with a prime mover provided with electrically responsive starting means, apparatus for automatically intermittently energizing the starting means including:

a first, relatively high current supply terminal adapted for coupling with a source of electrical energy; 1 i

a power circuit connected to said first terminal and adapted for coupling with said starting means for supplying current to the latter;

switching means coupled in said power circuit and having a first operational state for permitting current flow therein and a second, normal operational state preventing said flow,

said switching means being provided with electrically responsive operating means for effecting a change-ofstate of the switching means from said second to said first state thereof in response to relatively low current electrical excitation;

at second, relatively low current supply terminal adapted for coupling with said energy source;

a low current control circuit independentof said power circuit and interconnecting said operating means and said second terminal, said circuit including a timer for controlling current flow therein, and means for alternately energizing and de-energizing said operating means in response to current flow in said circuit, wehereby components of the circuit are not subjected to heavy currents required for cranking of the prime mover,

said timer including a switching device having a closed position for permitting current flow in said circuit and an open position preventing current flow therein, and means for operating the device to place the same in its closed position for a predetermined time interval representing the desired running time of the prime mover,

said circuit further including time delay means, normally permitting operation of said operating means, for disabling the latter in response to current fio-w in the circuit for a preselected period of time representing the total cranking time of the prime mover, said time delay means returning to its normal condition in response to operation of said switching device to place the latter in the open position thereof, Whereby subsequent closing of the switching device again effects operation of said energizing and de-energizing means to r e-crank the prime mover.

7. For use with a prime mover provided with electrically responsive starting means and electricall responsive fuel cutoff means, apparatus for automatically intermittently energizing the starting means and for preventing subsequent operation thereof by the apparatus, in the event that the prime mover fails to start, said apparatus including: 3

terminal means adapted for coupling with a source of electrical energy;

a power circuit coupled with said terminal means and adapted for coupling with said starting means for supplying current to the latter;

electrically responsive switching means coupled in said power circuit and having a first operational state for permitting current flow therein and a second, normal operational state preventing said flow;

circuit means intercoupling said switching means and said terminal means, and including a switching device for controlling operation of said circuit means, and means for repeatedly changing the operational state of said switching means in response to the operation of said circuit means;

control means coupled with said circuit means for rendering the latter inoperative, independently of the action of said switching device, after a predetermined time interval of operation of the circuit means, and including resett able switching structure for preventing further operation thereof by said switching device upon expiration of said interval;

means responsive to operation of said prime mover and coupled with said control means for rendering the latter inoperative upon starting of the prime mover, whereby to prevent operation of the control means if the prime mover starts within said time interval; and v a switching circuit adapted to be coupled with said fuel cutoff means,

said switching device being coupled with said switching circuit for controlling the latter to effect energization of the fuel cutoff means upon operation of the switching device to render the circuit means inoperative,

said switching circuit including time delay means responsive to current flow therein for interrupting the switching circuit after a predetermined period of time, whereby the fuel cutoff means is energized for said period of time to cease operation of the prime mover, thereby permit-ting re-starting of the prime mover subsequent to the expiration of said time period.

8. For use with a prime mover provided with electri cally responsive starting means and electrically responsive fuel cutoff means, apparatus for automatically intermittently energizing the starting means including:

terminal means adapted for coupling with a source of electrical energy;

a power circuit coupled with said terminal means and adapted for coupling with said starting means for supplying current to the latter:

electrically responsive switching means coupled in said power circuit and having a first operational state for permitting current flow therein and a second, normal operational state preventing said flow;

circuit means intercoupling said switching means and said terminal means, and including a switching device for controlling operation of said circuit means, and means for repeatedly changing the operational state of said switching means in response to the operation of said circuit means; and

a switching circuit adapted to be coupled with said fuel cutoff means,

said switching device being coupled with said switching circuit for controlling the latter to eifect energization of the fuel cutoff means upon operation of the switching device to render the circuit means inoperative,

said switching circuit including time delay means responsive to current flow therein for interrupting the switching circuit after a predetermined period of time, whereby the fuel cutoff means is energized for said period of time to cease operation of the prime mover, thereby permitting re-starting of the prime mover subsequent to expiration of said time period.

References Cited by the Examiner UNITED STATES PATENTS ORIS L. RADER, Primary Examiner. G. SIMMONS, Assistant Examiner.

Claims (1)

1. FOR USE WITH A PRIME MOVER PROVIDED WITH ELECTRICALLY RESPONSIVE STARTING MEANS, APPARATUS FOR AUTOMATICALLY INTERMITTENTLY ENERGIZING THE STARTING MEANS AND FOR PREVENTING SUBSEQUENT OPERATION THEREOF BY THE APPARATUS IN THE EVENT THAT THE PRIME MOVER FAILS TO START, SAID APPARATUS INCLUDING: TERMINAL MEANS ADAPTED FOR COUPLING WITH A SOURCE OF ELECTRICAL ENERGY; A POWER CIRCUIT COUPLED WITH SAID TERMINAL MEANS AND ADAPTED FOR COUPLING WITH SAID STARTING MEANS FOR SUPPLYING CURRENT TO THE LATTER; ELECTRICALLY RESPONSIVE SWITCHING MEANS COUPLED IN SAID POWER CIRCUIT AND HAVING A FIRST OPERATIONAL STATE FOR PERMITTING CURRENT FLOW THEREIN AND A SECOND, NORMAL OPERATIONAL STATE PREVENTING SAID FLOW; CIRCUIT MEANS INTERCOUPLING SAID SWITCHING MEANS AND SAID TERMINAL MEANS, AND INCLUDING A SWITCHING DEVICE FOR CONTROLLING OPERATION OF SAID CIRCUIT MEANS, AND MEANS FOR REPEATEDLY CHANGING THE OPERATIONAL STATE OF SAID SWITCHING MEANS IN RESPONSE TO THE OPERATION OF SAID CIRCUIT MEANS, SAID SWITCHING DEVICE HAVING A CLOSED POSITION FOR PERMITTING CURRENT FLOW IN SAID CIRCUIT MEANS TO PLACE THE SAME IN OPERATION, AND AN OPEN POSITION PREVENTING CURRENT FLOW THEREIN; CONTROL MEANS COUPLED WITH SAID CIRCUIT MEANS FOR RENDERING THE LATTER INOPERATIVE, INDEPENDENTLY OF THE ACTION OF SAID SWITCHING DEVICE, AFTER A PREDETERMINED TIME INTERVAL OF OPERATION TO THE CIRCUIT MEANS, AND INCLUDING RESETTABLE SWITCHING STRUCTURE FOR PREVENTING FURTHER OPERATION THEREOF BY SAID SWITCHING DEVICE UPON EXPIRATION OF SAID INTERVAL; AND MEANS RESPONSIVE TO OPERATION OF SAID PRIME MOVER AND COUPLED WITH SAID CONTROL MEANS FOR RENDERING THE LATTER INOPERATIVE UPON STARTING OF THE PRIME MOVER, WHEREBY TO PREVENT OPERATION OF THE CONTROL MEANS IF THE PRIME MOVER STARTS WITHIN SAID TIME INTERVAL; SAID CIRCUIT MEANS FURTHER INCLUDING TIME DELAY MEANS, NORMALLY PERMITTING OPERATION OF SAID STATE CHANGING MEANS, FOR DISABLING THE LATTER IN RESPONSE TO CURRENT FLOW IN THE CIRCUIT MEANS FOR A PRESELECTED PERIOD OF TIME SUBSTANTIALLY EQUAL TO SAID PREDETERMINED TIME INTERVAL, SAID TIME DELAY MEANS RETURNING TO ITS NORMAL CONDITION IN RESPONSE TO OPERATION OF SAID SWITCHING DEVICE TO PLACE THE LATTER IN THE OPEN POSITION THEREOF, WHEREBY SUBSEQUENT CLOSING OF THE SWITCHING DEVICE AGAIN RENDERS THE STATECHANGING MEANS OPERABLE IF STARTING OF THE PRIME MOVER HAS PREVIOUSLY BEEN EFFECTED PRIOR TO THE EXPIRATION OF SAID PREDETERMINED TIME INTERVAL.

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