US1875192A - Starter and re-starter for engines - Google Patents

Description

Aug. 30, 1932 L. H. MIDDLETON 1,875,192

STARTER AND RESTARTER FOR ENGINES Filed May 13, 1932 Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE LESLIE H. MIDDLETON, OF ADRIAN, MICHIGAN, ASSIGNOR TO SCHWARZE ELECTRIC COMPANY, OF ADRIAN, MICHIGAN, A CORPORATION OF MICHIGAN STARTER AND IRE-STARTER FOR ENGINES Application filed Kay 13, 1932. Serial No. 611,095.

This invention relates to control connections.

This invention has utility when incorpo rated in electrical connections, especially for effecting starting and automatic re-starting of prime movers as internal combustion engines, having electric starting motors, for operating motor vehicles.

Referring to the drawing:

Fig. 1 is a fragmentary view of a motor vehicle having an embodiment of the invention incorporated therewith, parts being broken away;

Fig. 2 is a wiring diagram with associated mechanical connections for the starter and re-starter of Fig. 1; and

Fig. 3 is a detail view of the plunger.

Motor vehicle 1 is shown provided with internal combustion engine 2, generator 3, starting motor 4, and starter drive connection 5. The operator of the vehicle at the operators station adjacent the steering wheel, to start the internal combustion engine 2 may insert ignition key 6 and turn such in barrel or chamber 7 The motor vehicle 1 has storage battery 8 provided with ground connection 9. From the storage battery 8 there is conductor 10 to contact 11 at the barrel 7. Turning of the key 6 outs in circuit for cur rent flow into conductor 12 to ignition coil 13, distributor 14 having communication to spark plugs 15. The generator 3 has thereon switch device 16 open at non-operative or non-generating condition of the generator 3, so that there may not be leakage from the battery 8 through conductor 17 and the switch 16 by way of conductor 18, brush 19 through the armature of the generator 3 to opposite brush 20 and conductor 21 therefrom to ground.

Upon starting of the idle generator 3 from the brush 19, there is energizing of coil 22 effecting closing of the switch 16 so that current flow may be to the battery 8 for charging thereof.

Starter motor 4 for turning the crank shaft at the engine 2, has the starting of such motor effected through conductor 23 from the battery 8 past starter switch 24 and conductor 25, extending directly to this motor 4. The

opposite side of this motor 4 has conductor 26 to ground in completing the starting circuit. The switch 24 of the starter motor is normzally maintained in open position by spring Under the invention of this disclosure there is, independent of the ignition circuit and independent of the ignition switch 11, switch 28 operable simultaneously with the switch 11, making connection from the line 18 to conductor line 29 extending to coil 30 through asymmetric cell 31, say of cupric oxide, for normal low resistance flow of current by line 32, through brush 19, to the armature of the idle generator 3 to the brush 20, and from the brush 20 to ground. This is a one-way flow circuit involving the plurality of cells 8 at the energy source and in series therewith the asymmetric cell 31 effective as an electromotive force dam or rectifier against flow of current from the generator 3 to the coil 30 by way of the line 32. In the design of this coil and cell feature of control for the starting switch, such circuit may carry, say 5 amperes with the resistance of .5 ohms, which under Ohms law computes for a voltage drop of say two and one-half volts at the coil 30, of .2 ohms for drop of one-half volt at the cell 31, and say of .4 ohms for drop of two volts through the idle armature at the generator.

With this coil 30 energized, stem 33 of the electro-ma'gnet is pulled against the resistance of the spring 27, closin the switch 24 and starting the motor 4. n pulling this switch 24 to closed position, adjustable stem 34 may vary the air gap so that the amount of pull necessary may be adjusted. This regulation is desirably one which, in the starting operation of the engine 2, has a slight holding action. The engine 2 is shown as provided with intake manifold 35 from which extends suction duct 36 to chamber 37 having therein flexible diaphragm 38 connected to the stem 33, to oppose the action of the coil 30 upon the reduction of pressure in the chamber 37.

The adjustment of the opposing means 34 may be such that in the starting speeds, wherein the vacuum in the chamber 37 may not be in excess of 7 inches, there is not an opening of the switch 24. However, as the ignition system is effective for producing firing in the motor 2, the speed of the motor at once jumps to, say 200 R. P. M., with the suction in the chamber 37 increased to approximately l4 inches of mercury. This at once pulls, say in the region of 11 pounds, upon the stem 33 for a quick snap opening of the starter switch 24 precluding arcing. The motor 4 is accordingly at once cut out as soon as the engine 2 starts firing. This speed of the engine at once picks up, operating the generator 3 to produce current for charging the battery 8. This charging current effects, through the coil 22, closing of the switch 16 and charging of the battery 8 occurs, as well as supply of current for the ignition system by way of conductor 10, switch 11, and conductor 12.

Without intervention of any switch means in this starter and re-starter circuit or any mechanical moving part, there is avoidance of current consumption in the coil 30, for this generator 3 upon starting to rotate establishes opposition to current flow even before generation therein and develops electromotive force in the conductors 18, 32, which opposes the flow from the battery 8 through the coil 30 and the cell 31. This opposition arising from rotation of the armature of the generator so reduces the total current flow through the coil 30 as to render such ineffective before excitation produces electromotive force from the generator in the conductors 18, 32, which is intercepted by the asymmetric cell 31. The cupric oxide rectifier, may reduce the current flow to such an extent that the electrical loss is negligible and is not of a character to heat the coil 30. In fact, this may be more or less the action of a check valve at this cell 31 serving as a dam against electric current flow by way of conductors 18, 32, past this cell 31.

It is thus apparent that during generator effectiveness, there is not electrical opposition to the vacuum opened switch 24 being retained open by the vacuum. However, as the engine 2 becomes stalled the generator 3 discontinues pumping of electric current charge to the battery 8 as well as discontinues opposing electromotive force counter to that from the conductor line 29 and in the coil 30. At this inactive position for the generator 3 and when the switch 16 is opened, the generator as a generator is thus out-ofcircuit with the storage battery, and as a non-generator the original starter circuit is effective to energize the coil 30. This energizing of the coil 30 may not be simultaneous with the stopping of the generator 3, but is retarded due to the leakage or slowness with which the intake 35 loses its negative pressure.

This means that there is normally a lapse of several seconds or an appreciable time interval from the actual stopping of the engine 2 and the generator 3 before the coil 30 may be efi'ective against what was the reduced pressure in the chamber 37. This time lag insures against cutting in of the starting motor 4 while the engine 2 is running. However, as this pressure drop which is below the idling speed for the engine 2, allows the coil 30 to close the switch 24, there is an automatic re-starting of the motor 4 for again putting the gas engine 2 in its driving connection effectiveness. The engine 2 may have an idling speed of around 350 R. P. M. However, in order that there may be a factor in the control, the suction effectiveness may be adjusted around that which is held at 200 R. P. M., this adjustment being due to the adjusting means 34.

It is accordingly seen that in the device of this disclosure, there is, independent of additional contacts or additonal switch means, the simple device of a coil and cell effective for closing the starter switch 24 and the release which may be effective by the spring 27, but herein shown as effected for snap action by the motor suction action upon diaphragm 38.

As the generator 3 is becoming effective to produce charging current for the battery, its resistance in the circuit for the coil 30 graduall increases somewhat along the line of a sine curve. This initial resistance may be .3 ohms at zero speed, or even .4 ohms as hereinbefore pointed out, and increases on the approximating of the sine curve to the point where the generator becomes effective and at which latter point, the resistance may be considered infinity. There is practical value in this interval for speeding up of the generator as increasing the resistance in this current for the coil 30, in that the current in the coil 30 has a gradual tapering off and there is thus avoided any counter-electromotive force kick. In the usual type of generators for automobiles, such may take 4% amperes at starting and consume about 2 amperes in getting up to speed. There is then a tapering off as the generator approaches 625 R. P. M. The armature resistance of the generator at idle positon, as hereinbefore indicated, is .3 ohms. As the armature is cranked or starts to rotate, this resistance is quickly built up to 1.05 ohms. As the speed 610 R. P. M. is reached, this resistance may be considered as approaching infinity. At 620 R. P. M. excitation may begin, while at 625 R. I. M., generation may be effective at 6 volts.

In the selection of the rectifier of copper oxide herein, such may have 3. volt drop as low as of a volt and an internal resistance of .150 ohms. Furthermore, it has a rectifying ability which may remain approximately constant during the normal life of an automobile. In the event of reverse current, the flow is checked to .125 watt. At 6 volts from the generator 3, it thus appears there is much less than .1 ampere of current.

The coil 22 is of a greater resistance than the resistance through the generator 3. This coil 22 does not become effective until there is the increased voltage as from the generator which is sufiicient to pull in the switch 16 to closed position. As so pulled in, line 18 has its connection through series coil 39 and the contact or switch 16 to the line 17. Such series coil is now effective for holding in this switch 16 to the closed position to which it has been pulled by the coil 22. r

The starting motor 4 may in practice be eflective, say through the mechanical or inertia drive 5 to effect rotation of the crank shaft forthe engine 2 at say 60 It. P. M. This preliminary or starting is not sufiicient to effect pulling of any considerable vacuum in the chamber 37. In fact, at the intake 35 such vacuum may only approximate, say 7 inches. However, as the firing of the engine 2 begins, say even as to three or four strokes, this pressure drop in the chamber 37 may be to as much as 14 inches. When this stem 33 has once been pulled, the operation of the engine, say at as low as 170 R. P. M. is sufiicient to maintain a vacuum in the chamber 37 to hold this switch 24 open.

The generator 3 attains its generating properties say at 600 R. P. M. This would mean that below such speed, the cell 31 would be in this series circuit to permit flow for energizing the coil 30. There may be control for adjusting the delay to a shorter interval for the coil 30 to respond in pulling the switch contacts 24 into closed position. This release for the intake pressure drop may be, as herein shown, by way of minute port 40 from the chamber 37 through this stem 33. This small leakage shortens the interval for pressure return to the chamber 37 upon stopping of the motor 2 and thus allows the coil 30 to take hold with less time lag.

In automobiles as now generally in use, the resistance of the generators through the brushes, say from the line 18 through the brushes 19, 20, may be .38 ohms. Under these circumstances as the generator speed approaches 650 R. P. M., the current opposition to flow in the line 32 has reached practically infinity, or at a speed slightly above this generating speed.

In the event the series control circuit 29, 30, 31, 32, be for 2.5 amperes and with'the generator drop .38 ohms, the gap in the sole noid between the stem 33 and the adjusting means 34 may be g of an inch. Adjustment of this pull may be varied by the variation in the clearances between stems 33 and 34. When this distance is zero, the pull may be 15.6 pounds; and when the gap is .0195 the pull may be 6.27 pounds; when .039 inch,

.34 pound; when .078 inch, .171 pound; when 4 inch, it is a fraction of an ounce.

In the pulling of the terminal 24 to seating position, this is yieldably effected for spring 41 about the stem 33 compensates for snug seating of this switch member 24. A satis factory pull at the air gap has been found in the range of 3 ounces for the adjustment of the means 34.

Importance attaches herein to the relation of the coil 30 as really a current coil, and not a voltage coil. Its relatively low resistance renders it non-responsive to low current. There is thus provided a safe-guard utility for this coil 30, even were the electric valve device 31 omitted. This rectifier 31 defeats reverse flow, but as well cooperates in the control circuit effectiveness at the cranking condition developing at the generator 3. Supplementing these and capable of independent action is the pneumatic snap-out from the engine intake effectiveness at the firing action of the engine 2.

What is claimed and it is desired to secure by Letters Patent is:

1. For an internal combustion engine installation embodying an engine having an intake, an electric energy source, a motor, a generator, means for rendering impotent a flow of current from the energy source to the generator reversely to the direction of flow of generator charging current to the energy source, a switch for cutting in the motor to start the engine, engine operated opening means from the intake for the switch, an electric closer for the switch in series with the generator, and asymmetric cell means in said circuit to prevent current generated by the generator being effective on said electric closer.

2. For an internal combustion engine installation embodying an engine, an electric energy source, a motor, a generator, a cutout for the generator, a switch for cutting in the motor to start the engine, and a control circuit connected across the cut-out and including a coil for operating the switch and an asymmetric cell in said control circuit.

3. For an internal combustion engine installation embodying an engine, an electric energy source, a motor, a generator, a cut-out for the generator, a switch for cutting in the motor to start the engine, and a control circuit connected across the cut-out, said control circuit having therein a coil for operating the switch and a copper oxide rectifier.

4. For an internal combustion engine installation embodying an engine having an intake, an electric energy source, a motor, a generator, a cut-out for the generator, a switch for cutting in the motor to start the engine, a control circuit connected across the cut-out, said control circuit embodying a coil for closing the switch, and an asymmetric cell, and a suction device from the intake for opening the switch.

5. For an internal combustion engine installation embodying an engine having an intake, an electric energy source, a motor, a generator, a cut-out for the generator, a switch for cutting in the motor to start the engine, a control circuit connected across the cut-out, said control circuit including a coil for closing the switch, and an asymmetric cell, a suction device from the intake for opening the switch, there being adjustable means for modifying the operation of said switch.

6. For an internal combustion engine installation embodying an engine, an electric energy source, a motor, a generator, a cutout for the generator, a switch for cutting in the motor to start the engine, and a control circuit connected across the cut-out, said control circuit having therein a coil to. operating the switch and means operatively responsive to the electrical condition of said circuit for precluding reverse current flow from the generator becoming effective for operating the switch through said coil.

7. For an internal combustion engine installation embodying an engine having an intake, and electric energy source, a motor, a generator, a cut-out for the generator, a switch for cutting in the motor to start the engine, and a control circuit connected across the cut-out, said control circuit having therein a coil for closing the switch and means operatively responsive to the electrical condition of said circuit for precluding reverse current flow from the generator becoming effective for operating the switch through said coil, and a suction device from the intake for opening said switch.

In witness whereof I afiix my signature.

LESLIE H. MIDDLETON.

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