US2054387A - Engine starting mechanism - Google Patents

Description

p 1936- R. M. NARDONE 2,054,387

ENGINE STARTING MECHANISM Original Filed May 26, 1930 Z'mventor omeo /7. Nara 077a Patented Sept. 15, 1936 UNITED STATES ENGINE STARTING MECHANISM Romeo Nardone, East Orange, N. J., assignor to Eclipse Aviation Corporation, East Orange, N. J a corporation of New Jersey Application May 26, 1930, Serial No. 455,816 Renewed August 10, 1934 9 Claims.

This invention relates to starters for internal combustion engines and more particularly tostarters of. the inertiatype;

One of the objects (if the present invention is to provide a simple, novel and reliable starter for internal combustion engines in which the starting operation is performed by the application to a rotatable member of the engine of energy which has been previously accumulated and stored in a rotatable inertia member of the starting apparatus.

Another object is to provide an engine starter of the inertia type in which novel actuating means are employed for rotating the inertia member and storing energy therein.

A further object is to provide an inertia starter which is characterized by the use of a fluid under pressure for actuating the inertia member of, the

starting mechanism.

Another object is to provide an engine starter of the type embodying an inertia member and actuating means for storing energy therein, in which the source of energy thus stored is an explosive cartridge.

A still further object is to provide an engine starter of the inertia type whichis characterized by the provision .of novel, fluid pressure operated, actuating means for rotating and storing energy in the inertia member in which the fluid pressure is generated by an automatic cartridge exploding mechanism.

These and other objects will appear more fully in the detailed description of the invention which follows. Although only one embodiment of the present invention is illustrated in the accompanying drawing, it is to be expressly understood that the drawing is for the purpose of illustration only and is not to be construed as'a limitation of the scope of the invention, reference being had for this purpose to the appended claims.

In the drawing:

Fig. 1 is a side view partly in section of one embodiment of the present invention;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; and v Fig. 3 is a plan view partly in section taken on line 33 of Fig. 1.

Referring now to the drawing wherein like reference characters indicate like parts throughout the several views, the embodiment of the present invention shown in Fig. 1 comprises a rotatable inertia member, novel means for actuating the inertia member including a fluid pressure engine.

and automatic pistol means for producing the fluid pressure therefor, and means including a gear train and drive for transmitting the energy stored in the inertiamember to a member of the engine to be started. The inertia member and energy transmitting means are housed in a'casing 4 of suitable form, having a flange 5 which 5 is removably secured to a portion of the engine casing 6 by any suitable means such as bolts 1.

Casing 4 is irregularly shaped and, as indicated in Fig. 1, comprises two approximately cylindrical contiguous portions. The upper portion pro- 10 vides a housing and bearing for a rotatable inertia member 8, preferably in the form of a flywheel, which is rigidly secured as by a key 9 and lock nut ill to a short shaft ll, said shaft being suitably journaled in casing 4 by means of. a bear- 1:; ing boss l2 and ball bearings l3. A pinion I4 is formed on the extremity of shaft ll opposite to the flywheel 8, the teeth of said pinion termiriating adjacent the ball races of bearings 13 and an annular retaining ring l5 secured to boss l2 as by screws 16 to hold said bearings and shaft in their proper operative positions within the casing. Flywheel 8 is preferably of small size and light weight, and is adapted for rotation at very high speed, the energy stored in the rapidly rotating flywheel being transmitted preferably through a train of reduction gearing and a yieldable driving connection to a member of the engine to be started. In the form shown, pinion l4 which is formed integrally with the outer end of shaft I l meshes with a gear I! which is rotatably mounted as by-means of a roller bearing l8 on a stub shaft l9 which is suitably journaled in a portion of easing 4. The hub of gear I1 is provided with gear teeth constituting a pinion 2G which meshes with a large external gear 2i having a hub 22 which is suitably supported on a hollow shaft 23 in a manner to be hereinafter described. I-lub 22 of gear 2| is also provided with gear teeth constituting a pinion 24 'whichin turn 40 meshes with a plurality of planetary gears 25, preferably three in number, one of which is shown in section in Fig. 1. These planetary gears are rotatably mounted on the outer face of a barrel shaped member 26 which is rotatable within casing 4 in the portion adjacent engine casing 6, the bearings for the planetary gears comprising ball bearings 21 surrounding sleeves 28 which are countersunk into the face of barrel 26 and secured thereto as by screws 29. An annular retaining 5 to casing 4 by any suitable means including a dowel pin 32 which is inserted in corresponding recesses in casing 4 and gear 3| for the purpose of absorbing the thrust developed by the meshing of planetary gears with the stationary internal gear 3|.

The rotation of flywheel 8 may thus be transmitted through a reduction gear train constituted by pinion ,I4, gear i'l, pinion 26, gear 2|, pinion 24, planetary gears 25, and ring gear 3| to the barrel 26. The rotation of the barrel 26 is in turn suitably transmitted, preferably through a yieldable driving connection, to a clutch jaw 33 which is adapted to be shifted axially into driving engagement with and to crank a corresponding clutch jaw 34 formed on a member of the engine to be started. In the I form shown, an interiorly threaded nut 35 is positioned inbarrel 26 and is drivably connected therewith by means of a friction clutch comprising a plurality of friction discs 36, alternate discs being splined to the interior surface of barrel 26 and to the exterior surface of nut 35. The discs 36 are held between an outer spacing ring 31 which is interposed between the outermost disc and the inner face of barrel 26, and an inner spacing ring 38 which is interposed between the innermost disc and a collar 39 formed on the nut 35.

Discs 36 are resiliently urged into frictional engagement. with one another by means of a plurality of coil springs 46 which bear at their inner ends against a plate 4| adjacent collar 39 and spacing ring 36, and exert their thrust against a nut 42 which is threaded into the outer end of barrel 26, and which provides a means for adjusting the torque transmission limit of the friction clutch. If desired, an annular ring 43 provided with a plurality of studs 44 may be employed to maintain springs in spaced relation within the barrel.

A short screw shaft 45 is positioned withinnut 35 and is exteriorly threaded to engage the threads formed in the interior of the nut, while the outer end of said screw shaft is splined to engage the interiorly splined hub 46 of clutch law 33. Any rotation of barrel 26 will therefore be transmitted through the friction clutch to nut 35 and thence by means of screw shaft 45 to clutch jaw 33.

Suitable means are also provided for moving the driving clutch jaw 33 into engagement with engine clutch jaw 34, and in the form shown comprises a rod 41 which extends centrally through screw shaft 45 and clutch jaw 33, and is provided' on its inner end with a nut 46 which limits the inward movement of clutch jaw 33. A coil spring 49 is provided surrounding rod 41 at its inner end and interposed between the outer face of clutch jaw.33 and the bottom of a recess formed in the inner end of screw shaft 45, for the purpose of yieldingly urging the clutch jaw inward. Rod 41 is also provided with a shoulder 56 engaging the outer end of screw shaft 45, so that when said rod is pushed toward the left as viewed in Fig. 1 by means hereinafter described,' the threaded engagement between shaft 45 and nut 35 causes said shaft to move toward the left, compressing spring 49 and resiliently urging clutch jaw 33 into engagement with clutch jaw 34. A nut 5| is provided on the outer end of screw shaft '45 and is adapted to abut a shoulder formed on the interior of nut 35 for the purpose of limiting the inward movement of screw shaft 45. When the engine to be started starts under its own power, clutch jaw 34 overruns clutch jaw 33 and the inclined faces of the teeth of said jaws are effective to' force clutcli'jaw 33 outwardly, or to the right as seen in Fig. 1, out of engagement with clutch jaw 34 and to restore the apparatus to the position shown in the draw- 5 ing. a

Although any suitable means, either manually or automatically operated, may be employed for moving rod 41 for the purpose of engaging driving clutch jaw 33 with the engineclutch jaw 34, 10 it is preferable to employ automatic means for thispurpose which are so designed as to be operable only when the flywheel 8 has reached a predetermined speed of rotation thereby insuring that a sufficient supply of energy has been stored 5 in the inertia member for the starting operation. In the form shown in the drawing, the automatic means comprises a governor mechanism operated by centrifugal force and drivably connected with flywheel 8 for actuation thereby. Re- 20 ferring now to Figs. 1 and 3, a shaft 53 is rotat-' ably journaled in the lower portion of casing 4 and is provided with a pinion 54 formed integral therewith which meshes with gear 2| thereby providing a driving connection for shaft 53 from 25 flywheel 8 through pinion L4, gear l1, pinion 29, gear 2|; and pinion 54. Shaft 53 is provided with astraight splined portion 55 on which is .mounted the correspondingly splined hub 56 of a plate 51, said hub seating against a shoulder 58 3 formed by one side of pinion 54. A plate 59 which is mounted on the hub- 56 and is suitably secured to plate 51, as by means of -a rivet or rivets 60, is provided with diametrically opposite. extensions in which are formed elongated slots 35 6|. Another portion of shaft 53 adjacent the straight splined portion 55 is provided with curved splines or threads 62 on which is positioned a correspondingly splined or threaded hub 63 having a flange or collar 64 formed on its 40 outer end, and a circular flange or plate 65 adjacent its inner end. A pair of similar irregularly shaped flyweights 66, provided with forked or bifurcated ends 61 and 68, are each pivoted at diametrically opposite points to the flange 65,by 45 suitable means such as pins 69 extending through the bifurcations 6| and preferably riveted in the flange 65. Pins 10 extend through and are preferably riveted in the bifurcations 66 of each of members 66, and said members 66 are resiliently 50 held inwardly close to the shaft 53 by means of coil springs H, each extending from a pin 10 of one member 66 to a pivot pin 69 of the other member 66. Flyweights 66 are positioned intermediate the flange 65 and plate 51, and each fly- 55 weight is provided adjacent the center of its outer periphery with a hole or opening 12 in each of which is positioned one end of a pin 13, the other end of each pin 13 engaging in the slot 6| in the plate 56. Pin 13 normally rests in the 60 inner end of slot 6|, and the plate 59, flyweights 66, and the member 63 and its flange 64 normally, rotate together as a unit with the shaft 53. When the speed of rotation of shaft 53 becomes sufficiently great, as determinedby the speed of flywheel 8, so that the tension of springs II is overcome and the flyweights 66 move radially outward, pins 13 moving outwardly in slots 61, relative rotation is produced between member 63 and plates 51 and 59, that is, between member 70 63 and shaft 53, and the splines or threads 62 cause member 63 to move longitudinally to the right as viewed inFigs. 1 and 3 toward the end of shaft 53.

This longitudinal displacement of the member 75 arm of lever 14 is provided with an elongated slot 18 which is engaged by a pin 18 secured in any suitable manner as by riveting to the outer end of the enlarged portion of rod 41. When the shaft 53 reaches a predetermined speed of rotation, which is directly proportional to the speed of flywheel 8, the flyweights 66 move radially outward, and member 63 moves longitudinally to the right as viewed in-Figs. 1 and 3, andthrough the medium of collar 11 and the bifurcated portion of lever 14 rotates said lever about itspivot which by means of the pin and slot connection shown at 18, 18 moves rod 41 longitudinally to the left thereby moving clutch jaw 33 into engagement with clutch jaw 34, as previously described. After the engine has started under its own power and the flywheel 8 has slowed down,

'flyweights 68 will be drawn in toward shaft 53 by springs 1| thereby drawing member 63 to the left and returning rod 41 and clutch jaw 33 to their original disengaged position by the action of flange 64 on the bifurcated portion of lever 14. A spring (not shown) is also preferably provided around shaft 14 which acts in a wellknown manner to resiliently urge lever 14 toward its normal position as shown in Fig. 1.

Referring now to the means for actuating and storing energy in flywheel 8 of the starting mechanism above described, it is desirable that such actuating means be not only simple and efflcient in operation, but also that it be reliable under all conditions of operation. It is preferable that such means be entirely independent of any extraneous source of energy such as an electric battery or a supply of compressed air, and accordingly the present embodiment discloses the use of a double acting fluid pressure engine, the motive fluid for which is generated by an automatic pistol means producing a succession of explosions which is drivably connected with the flywheel 8 through a suitable train of reduction' and also through a one-way driving flywheel may be driven by the engine but energy cannot be transmitted from the flywheel back to the engine. In the form shown, a single cylinder double acting fluid pressure engine is employed which is housed and supported in a suitable casing which is secured to main casing 4 in any preferred manner. .A cylinder block 8| provided with the usual fluid passages 82 and 83 and exhaust passage 84 is removably secured to casingflfl by any suitable means such as screws 85. A piston 86 having a rigid piston rod 81 reciprocates in cylinder 8|, the piston rod 81 extending downwardly through the upper portion of casing 80 through a stufling box 88 into a crank case 88 wherein the lower end -of piston rod 81 is drivably connected to the upper end 80 of a connecting rod 8| by means of the usual wrist pin 82. Connecting rod 8| is secured in any suitable manner to a crank pin 83 which forms an integral portion of a crank shaft 84 rotatably supported in bearings formed in casing 80. The inner end of crank shaft 84 extends within main casing 4 and is provided with a gearing, connection so. that the As shown in the drawing, a-

shaft 84 of the pinion 85 secured thereto by any suitable means such as a double-D 86 and a slotted lock nut 81, said pinion 85 meshing with a similar pinionv 88 which is formed integral with the outer end of hollow shaft 23, previously referred to.

Shaft 23, which is rotatably supported within casing 4 by means of ball bearings 88, retained in a suitable boss I00 by means of an. annular recess plate I02 and a lock nut and washer I03, and by a bushing IOI positioned within the face of barrel member 26, is adapted to transmit the rotation of crank shaft 84 of the fluid pressure engine to the flywheel 8 through a suitable train of reduction gearing and through a one-way driving connection. In the form shown, the train of reduction gearing comprises a portion of the gear train previously described as forming the driving connection between flywheel 8 and barrel member 26, namely gear 2|, pinion 20, gear I1 and pinion I4, while the one-way driving connection is constituted by a roller clutch interposed between a portion of shaft 23 and the hub 22 of gear 2|. This roller clutch, which is shown more clearly in Fig. 2, is of the usual type and comprises a plurality of elongated rollers I04 which are held between the inner surface of hub 22 of gear 2| and the outer surface of a portion of shaft 23 intermediate its ends in which there are provided a plurality of grooves I05 in which the'rollers I04 rest. Each groove I05 is so shaped as to provide a deep portion and a shallow portion, the respective depths being such that when the rollers I04 are in the deep portion of grooves I05, hub 22 may rotate freelyabout shaft toward the shallow end of the grooves they become tightly wedged between hub 22 and shaft 23 and form a driving connection therebetween. The normal position of rollers I04 when both shaft 23 and hub 22 are at rest is as shown in Fig. let the deep ends of grooves I05, and in this position rollers I04 are resiliently urged outward into frictional engagement with the interior of hub 22 by means of small coil springs I06 which are contained in suitable recesses I01 formed in shaft 23. The direction of rotation of both shaft 23 and hub 22 is clockwise as viewed in Fig. 2 so that, with both members at rest, if shaft 23 is started rotating due to its engagement with crank fluid pressure engine, rollers I04 will tend to move out of the deep portion of groove I05 and to be wedged between shaft 23 and hub 22 thereby forming a driving connection between these members which is adapted to transmit torque 4 When shaft 23 is stopped, or the speedof flywheel 8 becomes such that the speed of rotation of hub 22 is greater than that of shaft 23, rollers I04 will again be moved to the deep ends of grooves I05'and hub 22 will rotate freely about shaft 23 upon rollers I04 as its bearings. Rotation of crank shaft 84 can therefore be transmitted to flywheel 8 through shaft 23, the roller clutch and the reduction gearing, but due to the overrunning action of the clutch, rotation of flywheel 8 cannot be transmitted in the reverse force for the fluid pressure engine employed in the starter herein disclosed. As shown in Fig. 1, the automatic pistol means, which, by firing a succession of explosive cartridges generates a sup- 23, but when they are moved from'crank shaft 84 to flywheel 8.

I ply of high pressure fluid, is the same mechanism which is disclosed in Patent No. 1,572,998 issued to Rex Harris on February 16, 1926, and for that reason has not been shown nor described in detail herein. In general, however, the automatic pistol mechanism, indicated generally by reference character I08, comprises a magazine containing a plurality of explosive cartridges, a cartridge chamber, a barrel containing a bore, and firing and cartridge ejecting means, all of which are automatically actuated by means of an operating bracket member I09 which is given a reciprocating movement by a cam H driven by the crank shaft 94 of the fluid pressure engine through a suitable train of reduction gearing. In the form shown, the outer end of crank shaft 94 is provided witha pinion III secured thereto in any suitable manner as by means of a double-D 'H2 and a lock nut I I3, said pinion meshing with a plurality of planetary gears H4, preferably three in number, which in turn engage a stationary internal ring gear H secured to casing 80 by any suitable means such as screws H6.

which are held by means of a retaining plate I24 and screws I25 within a boss I26 formed in a cover plate I21 which is secured to casing 80 by any suitable means such as bolts I28. The outer end of shaft I22 extends beyond cover plate I21 and is provided adjacent its extremity with a cam H0 which is drivably secured thereto by any suitable means such as a key I30 which is formed integral with a collar I3I on shaft I 22 against which cam H0 is held by a nut I32. A roller I33 rotatably supported withinthe lower bifurcated portion of bracket operating member I09 bears upon cam H0 and, as the latter rotates, transmits a reciprocating'motion to member I00. A spring I34 is provided which bears against the upper end of member I09 thereby tending to maintain roller I33 in operative rela-,

tion with cam I I0 at all times. The reciprocating motion of operating member I09 is transmitted through suitable mechanism as described in Pat-- ent 1,572,998, so as to automaticallyperform the functions of loading, cocking, firing and ejecting the fired cartridges from the automatic pistol mechanism above described. a

The fluid under pressure which is generatedv by the automatic pistol mechanism I08 is supplied through a passage I35 to the valve chest I36 of the fluid. pressure engine from whence it is admitted to cylinder 8I at,th proper time by means of fluid passages 82 and wand a slide valve I31 of the usual D-type employed in double-acting engines. Valve I31 is operated in proper relation to piston 86 by any suitable means such as that shown herein which comprises a yoke I38 encircling a portion of valve I31, said yoke'having a stem I39 the lower end of which is threaded into the upper end of a'sleeve I43, the latter having a bifurcation-in which a rod I40 is pivotally connected by pin 144. The opposite endof the rod I40 is provided with a yoke portion Ill encirclinga cam I42 formed on crank shaft 94. Cam I42 is so shaped with respect to the position of crank pin 93 of the crank shaft 94 that slide valve I31 will be operated in the well-known manner so as to properly distribute the fluid under pressure to cylinder 8I for the purpose of operating the fluid pressure engine.

Describing now the operation of the present invention, it will beassumed that all parts of the starter mechanism are at rest and in the positions shown in Fig. 1. A supply of cartridges having been loaded in the magazine of the pistol mechanism and the firing device looked, as described in Patent No. 1,572,998, the fluid pressure engine is next placed in proper starting condition by rotating crank shaft 94 until a firing position of the piston mechanism is reached when piston 86 will be at one end of its stroke and one of the fiuid supply passages 82 or 83 will be in full communication with valve chest I36. Suitable means are provided for accomplishing this preliminary step in the starting operation which, in the form shown, comprise a pair of bayonet slots I45 formed in the hollow outer end of shaft I22 which are adapted to receive the lugs of an ordinary hand crank. A suitable indicator such as a pointer I46 which is held on shaft I22 between cam H0 and nut I32 is also provided to show when the starter parts are in proper position for starting.

The pistol mechanism is then unlocked and fired as described in PatentNo. 1,572,998 and the explosion of the cartridge generates a fiuid under high pressure which passes through passage I35 to valve chest I36 and thence to cylinder 8I of the fiuid pressure engine and the latter is started. It will be understood that from this time on until either all the cartridges contained in the magazine of the automatic pistol means are exhausted, or-until the pistol means is rendered in operative by the operator, successive. explosions will be automatically produced by therotation of crank shaft 94 which is transmitted through the reduction gearing and cam H0 to the pistol operating member I09. Flywheel 8 is then rotated and energy is stored therein due to the driving connection between crank shaft 94 of the fiuid pressure engine and shaft II of the flywheel, as previously described. Driving clutch jaw 33 is also rotated by crank shaft 94 during the acceleration period of flywheel 8 through the engagement of pinion 24 formed on the hub 22 of gear 2I with planetary gears 25. I Flywheel 8 continues to be accelerated byv the torque of crank shaft 84 until it reaches a. speed at which it tends to drive gear 2| faster than the latteris driven by shaft 23 through the roller clutch, at which time the overrunning action of saidclutch takes place and gear 2| rotates freely up'on' shaft 23. At this time, driving clutch, member 33 also ceases to be driven by crank shaft 84 and receives its rotation from flywheel 8. At the same time the rotation of fiywheel8 is being transmitted through gear 2| and pinion 54 to governor shaft 53, and, as previously described, when the speed of rotation of flywheel 8' reaches 3a predetermined amount, flywei'ghts 66 of the governor mechanism fly out from shaft 53 and, through member 63 and lever 14 cause rod 41 to be moved to been stored in the rapidly rotating fiywheel 8.

When the engine to be started starts under" its ,own power, clutch jaw 34 overrides the teeth of clutch jaw 33 and due to their inclined surfaces forces Jaw 33 back out of engagement. Should a backfire occur during the starting operation, the friction \clutch comprising friction discs 36 will operate to allow relative movement between the interiorly threaded nut 35 and driving barrel 26 thereby protecting the parts of the starter from injury. After the engine to be started is operating under its own power, the automatic pistol means may be rendered inoperative by the operator, if it has not already ceased t6 function due to exhaustion of the supply of cartridges. The fluid pressure engine will also cease to operate when the pistol mechanism is stopped, and as the flywheel 8 runs down, rod 41 will be fully withdrawn as previously described and all parts will be returned to their original positions as indicated in Fig. 1.

There is thus provided by the present inventionan inertia starter which is simple and rugged in construction and particularly reliable in operation due to the provision of novel'means for which are entirely selfcontained and which do not depend upon extraneous sources for their motive power. The inertia member of the starting mechanism disclosed in the present invention is adapted to be accelerated by a novel type of fluid pressure engine through suitable gearing-and a one-way actuating said starter clutch which allows torque to be transmitted from the fluid pressure engine to the inertia member but prevents its transmission in the opposite direction. The fluid pressure engine does not require the installation of an air compressor or other similar equipment for supplying a fluid under pressure, but is provided with an automatic pistol mechanism for this purpose, which, by the firing of successive explosive cartridges, generates a sufficient supply of fluid under pressure for operation of the fluid pressure engine, which feature makes this starter particularly well adapted for airplane usage. disclosed is also provided with means for automati'cally engaging the starter clutch jaw with a member of the engine to be started when the inertia member of the starting mechanism has reached a predetermined speed of rotation which assures that a sufficient supply of energy has been stored therein for the starting operation.

It will be obvious that the invention is not limited to the specific forms described and illustrated in the drawing, but is capable of a variety of mechanical embodiments. For instance, any suitable fluid pressure engine may be substituted for the one disclosed herein, and any suitable automatic pistol means might be substituted for that shown by the Harris patent.

It will also be understood that manual means may be employed for actuating rod 41 and causing engagement of the starter clutch jaw with that of the engine to be started. Various other features, which will now appear to those skilled in the art, may be made in the form, details of construction, and arrangement of the parts without departing from the spirit of 'the invention.

What is claimed is:

1. Engine starting mechanism including an inertia member rotatable at high speed, an engine engaging member movable into engaging position after acceleration of said inertia member to high speed, actuating means for said inertia member including a crankshaft having a gear train at each end thereof, means including a roller clutch for connecting one of said gear trains with said inertia member to accelerate the latter, means for liberating energy from an explosive 'charge to rotate said crankshaft, and means driven from charge, such transfer of energy erate said inertia member sufficiently to operate The starter herein to said inertia member, and means connected with the opposite end of said crankshaft for liberating additional energy to continue the rotation of said crankshaft and thereby accelerate said inertia member.

3. Engine starting mechanism including an inertia member rotatable at high speed, a crankshaft, a cartridge firing mechanism, a cylinder adapted to receive the expanding gases generated by the firing of a cartridge in said mechanism, a piston in said cylinder operativelyiconnected with said crankshaft, means connected with one end of said crankshaft to transfer energy to said inertia member,.and means connected with the opposite end of said crankshaft for actuating said cartridge firing mechanism to liberate additional energy to continue the rotation of said crankshaft and thereby accelerate said inertia member.

4. Engine starting mechanism including an inertia member, an engine engaging member, a gear train connecting said members, an explosive charge receiving chamber, means for firing a. charge in said chamber, means including a portion of said gear train for transferring to said inertia member the energy liberated from the fired acting to accelsaid engine engaging member, and means for providing a one-way driving connection between said last named portion of said gear train and said inertia member.

5. Engine starting mechanism including an inertia member, an engine engaging member, a gear train connecting said members, an explosive charge receiving chamber, means for firing a charge in said chamber, means including a portion of said gear train for transferring to said inertia member the energy liberated from the firing charge, such transfer of energy acting to accelerate said inertia member sufficiently to operate said engine engaging member, means for providing a one-way driving connection between said last named portion of said gear train and said inertia member, and means movable axially and centrally of said one-way driving connectionto move said engine engaging member into engine engaging position.

6. Engine starting mechanism including an inertia member rotatable at high speed, an engine engaging member tion after acceleration of said inertia member to high speed, an explosive charge receiving chamber, means for firing a charge insaid chamber,

movable into engaging posi- '7. Engine starting mechanism including an inertia member rotatable at high speed, an engine engaging member movable into 'engaging position after acceleration of said inertia member to. high speed, means for firing an explosive charge to liberate energy for storage in said inertia member to accelerate the latter, and means rotatable with said inertia member to cause a second explotional energy for storage in said inertia member.

8. Engine starting mechanism including an inertia member rotatable at high speed, an engine engaging member movable into engaging position after acceleration of said inertia member to high speed, means for firing an explosive charge to liberate energy for storage in said inertia member to accelerate the latter, means rotatable with said inertia member to cause a second explosive charge to be fired and thereby liberate additional energy for storage in said inertia member, and means for subsequently transmitting the energy thus stored in said inertia member to the engine.

9. Engine starting mechanism including an in- 7 2,054,887 sive charge to be fired and thereby liberate addiertia member rotatable at high speed, an engine engagingmember movable into engaging position after acceleration of said inertia member to high speed, means for firing an explosive charge to liberate energy for storage in said inertia mem-'- ber to accelerate thelatter, means rotatable with said inertia member to cause a second explosive charge to be fired and thereby liberate additional energy for storage in said inertia member, and means including a one-way clutch interposed between said firing means and said inertia member for limiting theamount of energy transferable to said inertia member.

ROMEO M. NARDONE.

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