US1329152A - Starting mechanism for internal-combustion engines - Google Patents

Description

H. R. EVAN VLECK.

STARTING MECHANISM FOR INTERNAL COMBUSTION ENGINES. APPLICATION FILED DEC. 12, 1911.

1,329, 1 52, Patented Jan. 27, 1920.

* UNITED STATES PATENT OFFICE.

HORACE RUSS VAN vLE'cK, 0E MONTCLAIR, NEW JERSEY, ASSIGNOR TO THE MOTOR- comraEssoa COMPANY, A CORPORATION 01* DELAWARE.

STARTING MECHANISM FOR INTERNAL-COMBUSTIQN IElIlq'GrIlZNES.v

To all whom it may concern:

Be it known that I, HORACE Russ V m. VLECK, a citizen of theUnited States, reading at Montclair, in thev county of Essex, State of New Jersey, have invented certain new and useful Improvements in Starting Mechanism for Internal-Combustion Engines; and I do hereby declare the followmg to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make andusethe same.

This invention relates tostarting mechanism for internal combustion enginesand Particularly for engines of-large size rotat ing normally at relatively high speed.

Internal combustion engines oflarge size rotating normally at relatively high speed and provided with an engine-driven magneto to supply the ignition current have heretofore been provided with starting mechanism, either electric or pneumatic, but such starting. mechanisms have frequently been" ineffective for the reason that within the limits of size imposed by weight and other onsiderations, they are capable of rotating he' engine shaft at only a very low speed. At such low 'speed, the magneto driven by the engine shaft and designed for normal operation at the normal high speed of the engine shaft is not rotated at a high enough speed to furnish the spark or the requisite hot spark. For this reason internal combustion engines of large size, such, for instance, as those employed on aeroplanes, have here- .tofore been provided with a manually operated magneto for use when starting, in addition to the engine-driven service magneto, usedduring normal operation. When this second hand-operated starting magneto has been provided, the practice has been to turn the engine shaft by hand, as by applying force to the blades of the ropeller driven by the engine, until the com ustible mixture has been drawn into all of the cylinders and thento turn the manually operated magneto rapidly by hand. This hand-actuated magneto is connected to the distributer employed in connection with the engine-driven magneto and through this distributer the current from the hand-actuated. magneto is carried to the spark plug of the cylinder whose piston is in the position appropriate for starting the engine by an explosion of the combustible gas in that cylinder.

Specification of Letters Patent. Patented J an. 27, 1920. Application filed December 12, 1917. Serial No. 206,745.

The present invention relates to starting mechanism of this type wherein a magneto is provided for use during starting in addithe shaft of the starting motor rotates at a speed several times that of the engine shaft, but notwithstanding this higher speed of the shaft of the starting motor during the startin operation, it may be desirable tohave the circuits of the starting magneto different from those of the service magneto in such a way as to produce the necessary hot spark at the lower speed.

Withsuch a starting mechanism, a much greater degree of reliability can be obtained in the starting of internal combustion engines of large size. The success of the starting-operation is not dependent upon the explosion of the combustible gas in a single cylinder for the reason that the rotation of the engine shaft and the operation of the starting magneto take place together and may ,cover a period of several revolutions of the engine shaft.

The invention may be employed in combination with'starting mechanisms of various types, as for instance, those employing either an electric or a pneumatic motor, the distinguishing characteristic of the invention I being that a starting magneto is employed in be connected to the starting motor compressor through an automatic one-way clutch' whereby the magneto is actuated only when motor mechanism is used as a compressor without harm to any of the parts.

One form in which the invention maybe employed is illustrated in the accompanying drawings showing a starting mechanism of the pneumatic type, but it will be understood that the invention is not limited to its use in connection with such a starting mechanism except as may be indicated in the claims appended hereto. In these drawings, Figure 1 is a diagrammatic view of an internal combustion engine and the starting mechanism employed therewith; Fig. 2 is a sectional elevation of the starting mechanism; and Fig. 3 is a detail view indicating a. slight modification of the construction shown in Fig. 2.

Referring to these drawings, 4 indicates 'an internal combustion engine of any suitable type having an engine shaft 5. A magneto 6 is suitably mounted upon the easi g ofthe engine and is connected by gears 7 in the usual manner to the engine shaft 5 so that it will be driven by the engine. The invention would ordinarily be employed in connection with internal combustion engines of large size rotating at relatively high speed such as those employed on aero planes, and the magneto 6 for such use would be specially designed to give a hot spark when driven at a speed corresponding to the high normal speed of the engine. The starting mechanism includes a motor 8 having a shaft 9, and this shaft is connected by any suitable gearing to the shaft 5 of the engine. In the present instance the shafts 5 and 9 are shown as provided with sprocket wheels on which a chain 10 runs. This gearing is proportioned for a substantial speed reduction from the shaft 9 to the shaft 5, such for instance,as a reduction from 7 to 1, whereby a motor 8 of relatively small size will be capable of starting the rotation of the engine shaft against thesubstantial resistance incident to starting the engine. When the motor 8 is operating at its normal speed and driving the engine shaft 5 at a speed which is very low c0mpared to the speed of rotation of the shaft 5 during normal operation of the engine, the magneto 6 geared to and driven by the engine shaft is rotated at such a low that it is not capable of generating a currentof a voltage sufficiently high. to insure that the engine will pick up and start operation under its own power. For this reason a second magneto 11 is provided for use in starting and is connected to the startspeed eeann;

rent of the magneto 6 is distributed to the spark plugs of the several cylinders of the engine 4. During the starting operation, the shaft 9 of the starting motor rotates at a speed which is so high relatively to the speed of the engine shaft 5 that a magneto 11 which is a duplicate of the magneto 6 would probably suffice to supply the necessaryhot spark for starting operation of the engine; however, as this magneto 11 is used only when startin the engine, it may be of small size and designed for meeting the condi tions incident to starting, that is, its electric circuits may be so proportioned that at the normal speed of rotation of the starting motor 8, the magneto 11 will supply the requisite hot spark at the spark plugs.

Fig. 2 shows a starting motor 8 of the pneumatic type, preferably one which is convertible so as to serve both as a motor and as a compression. The cylinders 14 have pistons therein which are connected by rods 15 to the crank shaft'9. In alinement with this shaft is a shaft 16 which is the engine shaft or is connected to the engine shaft by any suitable gearing. On one end of shaft 9 is a gear 17, the end of which formed to constitute one member of a clutch. The other member 18 of this clutch is splined on the shaft 16 so as to slide axially thereon into and out of engagement with the clutch member 17. Clutch.

member 18 is moved upon shaft 16 by a, 'lever 19 connected to a piston 20 in a cylinder 21. Air may be admitted to the cylinder 2]. by a valve 22 to move the piston. 20 and clutch member 18 in one direction, and this movement is efl'ected against the tension of a spring 23 which moves the piston and clutch member in the opposite direction when air is permitted to escape from cylinder 21.

A counter-shaft 24 mounted in the casing of the starting motor carries a gear 25, which,.through an idler 26, meshes with the gear '17. Shaft 24 also carries an axially movable gear 27 adapted to mesh with a gear 28 formed on the clutch member, 18. Shaft 24 has a spiral thread 29 thereon which is received in a spiral gearing on the interior of the hub of gear 27.

When it is desired to start the engine, air under pressure is admitted to the cylinders 14 of the starting motor and causes thesha ft 9 thereof to rotate. This drives enema 24 through the gears 17 26 and 25, and the spiral thread 29 on shaft 24 moves gear 27, axially until it comes into mesh with gear 28 and thus drives the shaft 16 which is connected to the engine shaft. After the engine has been started, the supply of air to the cylinders 14 is discontinued. When it is desired to compress air in the storage tank, the connection from the cylinders 14 to the tankis open and air is admitted by valve 22 to the cylinder 21. Thismoves the piston 20 and lever 19 so as to move the clutch member 18 into engagement with the clutch member 17. This connects the shaft 16 which is connnected to the engine shaft in driving relation to the shaft 9 so as to op erate the starting motor asa compressor.

The starting magneto 11 is mounted upon the casing of the starting motor.. The shaft 9 of the starting motor is extended through an opening of the casing and is connected to the shaft of the magneto 11. Leakage of lubricating oil from the casing through the opening through which shaft 9 extends is prevented by a washer 30 held against the side of the casing by a spring 31.

In the construction shown in Fig. 2, thestarting magneto 11 is rotated both when the starting mechanism is operating as a motor and when it is operating as a compressor. If desired, an automatic one-way clutch may be interposed between the end of shaft 9 and the shaft of the starting magneto 11, as indicated at 32 in Fig. 3, so that the magneto 11 will be driven only when the starting mechanism is operating as a motor.

In the foregoing, the preferred embodiment of the invention has been described, but it will be understood that the invention may be embodied in other 'forms. For instance, the current from the starting magneto may be utilized in starting in a different way; it may be supplied to a second set of spark plugs without passing through the distributer of the service magneto or it may be supplied to one winding of the service magneto so as to utilize the windings of that magneto as a step-up transformer.

The convertible pneumatic motor compressor above described operates in one direction as a motor and in the other direction as a compressor. When an electric starting motor is employed, this rotates in the same direction as a motor and as a generator storing electrical energy in the battery.

Therefore, with an electric starting motor,

the automatic one-way clutch indicated in Fig, 3 as connecting the starting motor to the starting magneto, would not suffice to allow the magneto to remain idle when-op.- erating the starting device by the engine to store energy; instead, the connection from the starting motor to the starting magneto would be electridally controlled and dependent on the direction of flow of current in the starting motor circuit so that when operating the starting device as a generator, the starting magneto would remain at rest.

1. The combination with an internal combustion engine having a magneto geared to shaft is driven by the starting'lnotor; substantially as described.

2. The combination with an internal combustion engine having a magneto geared thereto and driven thereby for supplying ignition current during normal operation of the engine, of a starting motor geared to the engine shaft through speed reducing gearing for starting the engine in operation by rotating the engine shaft at a low speed relatively to the speed of the starting motor until the engine begins to operate under its own power, and a starting magneto electrically connected to the ignition circuit of the engine and connected to the shaft of the starting motor so as to be driven by the starting motor at the speed of the latter during the starting operation when the engine shaft is being driven by the starting motor; substantially as described.

3. The combination with an internal combustion engine having a magneto geared thereto for supplying ignition current during normal operation of the engine, of a convertible pneumatic motor compressor, speed-reducing gearing connecting the shaft of the motor compressor to the engine shaft, a starting magneto connected mechanically to the shaft of the motor compressor so as to be driven thereby and connected electrically to the ignition circuit of the engine, and an automatic one-way clutch in the connection from the motor compressor shaft to the shaft of the starting magneto whereby the starting magneto is driven only when the motor compressor is operating as amotor; substantially as described.

4. The combination with an internal combustion engine having a service magneto geared thereto and driven thereby for supplying ignition current during normal operation of the engine, of a starting motor geared to the engine shaft through speed-reducing gearing for starting the engine in operation by rotating the engine shaft at a low speed relatively to the speed of the starting motor until the engine begins to operate under its own power, a starting magneto and connections through which the starting magneto is actuated when the motor shaft is rotated to start operation of the engine, the gearing being such that during the starting operation the shaft of the starting magneto is driven at substantially higher speed than the shaft of the service magneto so as to supply the requisite spark during the relatively slow rotation of the engine shaft; substantially as described.

5. The combination with an internal combustion engine having a service magneto geared thereto and driven thereby for supplying ignition current during normal operation of the engine, of a starting device geared to the engine shaft through speedreducing gearing for starting the engine in operation by rotating the engine shaft at a low speed relatively to the speed of the starting device until the engine begins to operate under its own power, said starting device being adapted to be driven by the engine to store energy, a startingmagneto adapted to be connected to said starting device to be operated thereby during the starting operation and connected electrically to an ignition circuit of the engine, and automatic means for connecting the starting magneto to the starting device when the latter is operated to start the engine and for'disconnecting the startin magneto from the starting device when the'latter is operated by the engine to store energy; substantially as described.

6. The cbmbination with an internal com bustion engine and a service magneto coupled to supply ignition current thereto during normal running, or a power-actuated starting mechanism connected with the engine shaft for rotating it at a speed which is relatively low as compared with the speed of the starting mechanism until the engine commences to operate under its own power, and a starting magneto connected electrically with the engine and mechanically with the starting mechanism so as to be positively driven by and at the same speed as the starting mechanism in order to supply the requi site spark to the engine during the time that the latter is being driven by the starting mechanism; substantially as described.

7. The combination with an internal combustion engine and a service magneto coupled to supply ignition current thereto during normal running, of a device adapted to be connected to the engine shaft to rotate the same and thereby start the engine, a starting magneto for supplying ignition current to the engine during the starting operation, and a driving train connecting the starting device with the engine shaft and comprising an element which is shiftable bodily in one direction to complete the train and in the opposite direction to interrupt the train; substantially as described.

8. The combination with an internal combustion engine and a service magneto coupled to supply ignition current thereto during normal running, of a device adapted to be connected to the engine shaft to rotate the same and thereby start the engine, said start.- ing device being adapted to be driven by the engine to store energy, a starting magneto for supplying ignition current to the engine during the starting operation, and a driving train connecting the starting device with the engine shaft and comprising "a ear which is automatically moved in one direction to complete the train when the starting device is operated to start the engine, and is automatically moved in the other direction to interrupt the train when the starting device is operated by the engine to store energy; substantially as described.

9. The combination with an internal combustion engine and a service magneto coupled to supply ignition current thereto during normal running, of a device adapted to be connected to. the engine shaft to rotate the same and thereby start the engine, said starting device being adapted to be driven by the engine to store energy, a starting magneto for supplying ignition current to the engine during the starting operation, and a driving train connecting the starting device with the engine shaft and comprising an element which automatically completes the train when the starting device is operated to start the engine and which automatically interrupts the train when the starting device is operated by the engine to store energy; substantially as described.

In testimony whereof I afix my signature.

HORACE RUSS VAN VLECK.

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