US1932979A - Automatic starting mechanism - Google Patents

Description

Oct. 31,1933. P, H, MAU-RER I AUTOMATIC STARTING MECHANISM Filed Jan. 26. 1932 INVENTOR PM H. w BY ,J m

7A ORNEY Patented a. 31, 1933 PATENT OFFICE I 1,932,979 AUTOMATIC STARTING MECHANISM Paul H. Maurer, Elmira, N. Y., assignor to Eclipse I Machine'Company, Elmira, N. Y., a corporation of New York Application January 26, 1932. Serial No. 589,037

6 Claims.

circuit breaking means.-

In the operation of automatic starting mechanisms which depend on electro-magnetic means energized from the starting battery for controlling the breaking of the starting circuit, it has-been found that the performance of such means depends to a considerable degree on the condition of the battery. In particular, appreciable variations have been observed in the performance of such means when the battery is nearlyexhausted from the action when the battery is fully charged.

It is an object ,of the present invention to provide a novel automatic starting mechanism which is reliable and uniform in its action regardless of variations in operative conditions.

It is another object to provide such a device which embodies provisions for preventing variations in battery conditions from affecting the operation thereof.

It is a further object to provide such a device which embodies an automatic regulating element which counteracts the effect of'variations in battery voltage.

Further objects and advantages will be apparent to those skilled in this art from the following description taken in connection with the accompanying drawing which illustrates semidiagrammaticallya preferred embodiment of the invention.

Referring to the drawing, there is illustrated an electrical starting system for an internal combustion engine, not shown, including a battery 1, grounded at 2, connected by a lead 3 to an automatic starting mechanism indicated generally by numeral 4. The automatic starting mechanism comprises a magnetic starting switch 5 which is connected through a sin le turn coil 6 and a lead '7 to .a starting motor SM, said motor being grounded at 8 to complete the starting circuit.

The starting switch 5 is adapted to be operated by a solenoid coil 9 which is energized by a control circuit from battery 1 including battery lead 3, ignition switch 11, leads 12 and 13, fixed contact 14 and movable contact 15 mounted on ,a spring stripl6 which is grounded at 17 to complete the control circuit. Contact 15 is normally maintained in engagement with fixed contact 14 by the spring strip 16, but is arranged to be moved out of engagement therewith by means of a lever 18. Said lever'is pivoted at 19 and is operated by a plunger 21 to engage a weight member 22 on the end of the spring strip 16, and bend said strip backward. Plunger 21 is normally maintained in its upper position as illustrated by 9 suitable means such as a spring 23, and its position is controlled by the action of the single turn coil 6 which tends to hold the plunger in its upper position, and'by two solenoid coils, a voltage coil 24 and a generator coil 25 which when energized attract the plunger downwardly.

Voltage coil 24 is connected by a lead 26 to the starting motor side of the starting switch 5, and is grounded at 27 whereby closure of the starting switch causes energization of the coil from the battery 1. Generator coil25 is connected by a lead 28 to the generator G and is also grounded at 2'7 whereby self-operation of the engine causes the generator to energize coil .25 toretain plunger 21 in its lower position. L

In the operation of the automatic starting mechanism as so far described, closure of the ignition switch 11 closes the control circuit, causing energization of solenoid 9 which closes the starting switch 5, completing the starting circuit and causing the engine' to be cranked. At this time, the voltage coil 24 is energized but isunable to pull the plunger 21 downwardly by reason of the magnetic effect of the heavy cranking current which traverses the single turn coil 6. 35 When the engine starts, however, the release "of the cranking load causes a large reduction in the current traversing the single turn coil 6 whereby the magnetic effect is weakened sufliciently to allow the voltage coil 24 to draw the plunger 21 9 downward. This-causes lever 18 to engage and bend backward the spring strip 16 thereby opening contacts 14, .15 and breaking the control circuit. The self-operation of the engine causes the generator G to pick up and energize the holding coil 25 whereby the plunger 21 is maintained in its lower position with contacts 14, 15 open as long as the engine is in operation. I

It has'been' found in the operation of devices of this character that, in certain installations, the latitude of adjustment of the balance between the single turn coil 6 and the voltage coil 24 is comparatively narrow and that the voltage coil 24 is affected by the condition of the battery to a greater degree than the current coil 6. In other words, even though the battery is in a comparatively low state of charge, the cranking current will not be greatly reduced from the cranking current 'with a fully charged battery, but the voltage of. the battery during cranking will be very considerably lower when the battery is nearly discharged, than the cranking voltage when the battery is fully charged. The result is that an automatic starting device which has been adjusted to function properly with a fully charged battery may not disengage when the engine starts it the battery is nearly discharged, since the voltage coil 24 is too weak to pull down the plunger 21 against the efiect of the current coil 6, so that the motor spins continuously until the ignition switch is opened.

On the other hand, a device which is adjusted for a condition of low battery charge may, when used with a fully charged. battery, cause interrupted cranking to occur. That is, after the first rush of current through the starting circuit in breaking the engine loose, the voltage coil 24 may pull the plunger 21 down even though the starting motor is cranking the engine; whereupon the starting switch 5 will be opened, voltage coil 24 deenergized, and the operation repeated.

, In order to avoid both these possibilities and to stabilize the action 01 the coil 24 regardless of the condition of the battery 1 within normal operating limits, according" to the present invention, an automatic regulating device 29 is placed in series with the voltage coil 24. This automatic regulating device is preferably as indicated in the form 01' a constant current device of the type which permits a certain fixed current flow therethrough but interposes an increasing resistance in the circuit when the voltage applied thereto is increased, whereby the current is maintained substantially constant regardless of normal variations in the voltage applied thereto.

As here illustrated, this device comprises a resistance wire 31 of material having a high positlve temperature coeflicient such as iron, sealed in a suitable tube or capsule 32 in'an inert atmosphere such as hydrogen or helium. Such a device may readily be designed to transmit a suitable current tor actuating the voltage coil 24 without causing appreciable heating of the wire 31 but so proportioned that an increase in voltage applied to the circuit will cause the wire 31 to heat up and prevent more than the desired amount of current from passing therethrough.

In the operation of this device, the automatic starting mechanism is adjusted for the desired operation with respect to the control of plunger 21 with the minimum voltage of battery 1 which 7 may be encountered in service. Satisfactory operation of the device under all circumstances is then assured by the controlling element 29 since increase in voltage of the battery 1 is automatically off-set by the increase in resistance of said controlling element whereby the voltage coil 24 al ways acts in a uniform manner.

Although but one form of the invention has been shown and described in detail. it will be understood that various changes may be made in the construction and arrangements of the parts and certain of the elements may be used without others thereof without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:-

1. In combination with a starting mechanism for internal combustion engines including a battery, a motor, and a starting switch, manually controlled means for causing closure of the starting switch, electro-magnetic means for causing said switch to be opened when the engine starts, and means for causing a substantially uniform operation of said electro-magnetic means regardless of variations in the voltage applied thereto.

2. In combination with a starting mechanism for internal combustion engines including a battery, a motor, and a starting switch, manually controlled means for causing closure of the starting switch, electro-magnetic means for causing said switch to be opened when the engine starts, and means for maintaining a substantially constant flux density in said electro-magnetic means regardless of normal variations in the voltage applied thereto.

3. In combination with a starting mechanism for internal combustion engines including a battery, a motor, and a switch, electro-magnetic means for opening said switch, and means for maintaining the flux of said electromagnetic means substantially uniform regardless of normal variations in the voltage of the battery.

4. In combination with a starting mechanism for internal combustion engines including a source of current supply, a motor, and a switch. electro-magnetic means for opening said switch, and means for maintaining the current flow through said electro-magnetic means substantially uniform regardless of fluctuations in the electromotive force of the current supply.

5. An'automatic starting mechanism for internal combustion engines including a source of current supply, a motor and a starting switch, electro-magnetic means energized by closure of said switch for causing said switch to be opened when the engine starts, and an automatic variable resistance in said circuit with said electromagnetic means for maintaining the current flow therethrough substantially constant.

6. A starting system for internal combustion engines including a battery, a starting motor, and a magnetic starting switch, means for closing said switch in case of engine stall, means energized by closure of the starting switch and controlled by the starting current for maintaining said switch closed until the engine starts means energized by closure of the starting switch and controlled by the battery voltage for opening said switch when the engine starts, and means for maintaininguniform operation of the voltage controlled means regardless of normal variations in the voltage of the battery.

PAUL H. MAURER.

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