Title:
Two-stage starter control
United States Patent 2178098


Abstract:
The present invention relates to a two-stage starter control for heavy duty internal combustion engines and more particularly to a device for ensuring engagement of starter gear 3 drives prior to the application of the full battery voltage to the starting motor. In the operation of starter...



Inventors:
Elkin, Manuel H.
Application Number:
US23283238A
Publication Date:
10/31/1939
Filing Date:
10/01/1938
Assignee:
BENDIX AVIAT CORP
Primary Class:
International Classes:
F02N11/08
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Description:

The present invention relates to a two-stage starter control for heavy duty internal combustion engines and more particularly to a device for ensuring engagement of starter gear 3 drives prior to the application of the full battery voltage to the starting motor.

In the operation of starter drives of the larger and heavier types used to crank large internal combustion engines such as Diesel engines, it is customary to use large starting motors actuated by 12, 24 or even 30 volt batteries. If the full battery voltage is applied to such starting motors before the drive gearing is fully meshed, heavy shock loads are imposed on the parts which ne1i cessitate the use of more expensive types of drive gearing than might otherwise be used.

It is an object of the present invention to provide a novel starter control which initially energizes the starting circuit at a reduced voltage, and after the gearing is meshed, applies the full voltage to the starting circuit.

It is another object to provide such a device which automatically introduces a time delay between energization of the starting circuit at low B voltage and the application of the full voltage thereto, said time delay being sufficient to insure the full engagement of the drive gearing prior to the application of the high voltage to the starting motor.

It is a further object to provide such a device which is readily adaptable for use in connection with a manually operated sa starting switch.

It is another object to provide such a device in which the time delay is at all times effective to W6 protect the drive irrespective of erratic and repeated actuation of the manual switch.

It is another object to provide such a device which is simple and economical in construction and efficient and reliable in operation. Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which: Fig. 1 is a semi-diagrammatic representation of a starter control embodying a preferred form of the invention, showing the parts in their normal or idle position; and Fig. 2 is a similar view of a second embodiment of the invention showing the parts 'in cranking position.

In Fig. 1 of the drawing there is illustrated an engine starting system comprising a starting circuit including a battery I, a starting motor SM, a manually operable starting switch 2, and 65 a resistor 3, said elements all being connected in series as indicated whereby closure of the starting switch 2 causes energization of the starting motor from the battery by a voltage reduced by the voltage drop through the resistor 3. One side of the starting motor and one side of the battery are grounded as indicated at 10.

A switch 4 is provided for bridging the resistor 3 in order to apply the. full battery voltage to the motor, and electromagnetic means for closing the bridging switch are provided including an electromagnet 5 connected at one end by a lead 6 to the starting switch 2, and at the other end by a lead 7 to a fixed contact 8. A movable contact c is mounted on a pendulum formed by a spring strip I I fixedly mounted and grounded at one end as indicated at 12 and having at its free end a weight member or bob 13.

Means are provided for normally holding the movable contact 9 out of engagement with fixed contact 8 in the form of a lever 14 pivoted at 15 and urged by a spring 6 into emengagement with a stop 17, in which position a roller 18 on the end of thedever engages the. bob 13 of pendulum Si and deflects the pendulum so as to maintain contacts 8, 9 open. Means for moving the lever 14 into inoperative position while at the same time setting the pendulum II into vibration, is provided in the form of an electromagnet 19 connected at one end by a lead 21 to the lead 6 coming from the starting switch 2 and grounded at the other end as indicated at 22. Coil 19 is arranged to attract a magnetic plunger 23 which is connected as indicated at 24 to operate the lever 14.

In the operation of the device, starting with the parts in the positions illustrated in Fig. 1, closure of the starting switch 2 completes the starting circuit through the resistor 3 whereby .the starting motor is energized at low voltage to engage its gearing with a member of the engine to be started. It will be understood that any usual or preferred form of automatically engaging starter drive may be employed such, for instance, as.that shown in the patent to Douglas 2,071,028, and illustration thereof is deemed unnecessary.

Closure of the starting switch 2 also completes the circuit through lead 21 and coil 19 to the ground whereby the plunger 23 is attracted, swinging the lever 14 out of engagement with the bob 13 of pendulum i I and setting the pendulum in vibration with the assistance of the wedge-shaped projection on the bob 13. After a predetermined period of vibration, the contact 9 comes to rest against the contact 8, whereupon the control circuit is completed through lead 6, coil 5, contacts 8, 9 and grounds 12 and '10 whereby the switch 4 is closed, shunting out the resistor 3 and applying full battery voltage to the starting motor to crank the engine. When the engine starts, opening of the starting switch 2 by the operator causes all the parts to return to their idle positions.

It will readily be seen that due to the arrangement of the coil 5 of electromagnetic switch 4 and coil 19 of the time delay mechanism under the control of the starting switch 2, the starting system is always completely under the control of the operator. However, since the lever 14 Is actuated by the spring 16 to open contacts 8, 1 immediately upon deenergization of coil II, and these contacts cannot reclose thereafter until after the time delay caused by the vibration of the pendulum II, it is clear that the time delay is always effective to prevent premature closure of the bridging switch 4 irrespective of intermittent or erratic operation of the starting switch 2.

The starting switch 2 may be of any preferred character, and may be electromagnetically operated from a distance if desired. Such an arrangement is illustrated in Fig. 2 in which the starting switch 2 is operated by an electromagnet 25 connected at one end by a lead 21 to the battery and at its other end by a lead 27 to a control switch 28, closure of which completes a ground connection at 29.

It will be understood that the present disclosure is not exclusive, and that various changes may be made in the design and arrangements of 31 the parts illustrated without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is: 1. In an engine starting system, a starting circult including a battery, a motor, a starting switch for energizing the motor from the battery, and a resistor in series with the switch and motor for reducing the voltage of the battery initially applied to the motor, a switch for bridging said resistor to apply the full battery voltage to the motor, electromagnetic means for closing said bridging switch comprising a control circuit including a coil and a pair of normally open contacts in series with the starting switch and battery, and electromagnetic means also in series with the starting switch and battery for closing said contacts a predetermined time after the closure of said starting switch.

2. In an engine starting system, a starting circult including a battery, a motor, a starting switch for energizing the motor from the battery, and a resistor in series with the switch and motor for reducing the voltage of the battery initially applied to the motor, a switch for bridging said resistor to apply the full battery voltage to the motor, electromagnetic means for closing said bridging switch comprising a control circult including a coil and a pair of contacts in series with the starting switch and battery, means normally holding said contacts open, electromagnetic means for actuating the holding means to permit the contacts to close, and means for vibrating said contacts a predetermined time before effective engagement thereof.

3. In an engine starting system, a starting circuit including a battery, a motor, a starting switch for energizing the motor from the battery, and a resistor in series with the switch and motor for reducing the voltage of the battery initially applied to the motor, a switch for bridging said resistor to apply the full battery voltage to the motor, electromagnetic means for closing said bridging switch comprising a control circuit including a coil and a pair of contacts in series with the starting switch and battery, a yielding pendulous member carrying one of said contacts and permitting movement thereof into and out of engagement with the other'contact, a pivoted lever, yielding, means for moving said lever to engage and deflect the pendulum to open the contacts, and means including an qlectromagnetic coil in series with the starting switch for moving said lever out of engagement with the pendulum, said lever and pendulum having means cooperating to set the pendulum in vibration when the lever is disengaged therefrom.

4. In a two-stage control system for engine starters, a starting circuit including a battery, a motor, a manually operable starting switch for connecting the battery to the motor, and a resistor for reducing the voltage of the battery initially applied to the motor through said starting switch, an electromagnetic switch for bridging said resistor to apply full battery voltage to the motor, a circuit for closing said electromagnetic switch including the battery, the starting switch and a pair of contacts spring-biased to closed position, means normally holding said contacts open, electromagnetic means energized gg by closure of the starting switch for rendering said holding means inoperative, and means delaying effective closure of the contacts for a predetermined time.

MANUEL H. ELKIN.