US1235162A - Engine-starting motor. - Google Patents

Description

SAMUEL W.' RUSHMORE, OF PLAINFIELD, NEW JERSEY.

ENGINE-STARTING Moron.

Specication of Letters Patent. i Patented July 31, 1917,

Application filed September 27, 1912. Serial No. 722,629.

To all whom t may concern.'

Be it known that I, SAMUEL WILLIS RUSH- MORE, a citizen of the United States, residing at Plaineld, in the county of Union and `State of New Jersey, have invented new and useful Improvements in Engine-Starting Motors, of which the following isa specification.

This invention is an improved engine star ter for internal combustion engines and is of that type in which an axially movable gear .is brought into mesh with an engine fly-wheel to transmit power to the latter and 'tc the engine for starting the engine, and is automatically moved axially out of mesh when the engine takes up its cycle of operation.

The invention resides primarily in themeans for automatically effecting this engagement and disengagement and the main objects of my invention are to render such engagement and disengagement more reliable, positive and instantaneous and without the use of gear-shift levers, ratchet clutches, etc., which, with the necessary interlocking connections, involves considerable complication and expense. My novel arrangement results in a considerable saving in weight, space required and electrical energy.

As one important feature of the invention, the shiftable pinion is pulled endwise into mesh by electro-magnetic action resulting from the closing of the circuitpf the electric motor employed to rotategsaiid'pinion.

By Imeans of this arrangement, the faster driving of the armature'when`the engine takes up its cycle of operation results in an increase in the counter-electromotive force and a decrease in the endwise magnetic pull which permits a spring or other means to return the pinion to its normal disengaged position. As a simple and effective means for accomplishing this, I preferably connect the pinion directly to the armature shaft and permit the shaft and armature to slide endwise within the field of the electricmotor.

As a further important feature, I employ helical gears, the inclination of the gear teeth being such that the end thrust thereon tends to hold the axially movable gear in mesh when it is rotated to drive the engine and shifts or aids in shifting it out of mesh when it is rotated by the engine when the latter takes up its cycle of operation.

In the accompanying drawings which show a preferred and desirable embodiment of my invention the parts are designated by similar characters in both of the figures which illustrates my invention diagrammatically and of which Figure 1 shows the normal disengaged position of the parts when the motor is inactive and Fig. 2 shows the parts in the position of engagement to start the engine when the motor is ener' gized.

In the figures A indicates an electric motor having series wound field oles 2 and 8. 4 is an armature having an e ongated shaft 4 running in bearings 5 and 6. 7 is a helical gear or pinion on the end of the armature shaft and adapted to engage with the helical gear teeth 8 cut in the rim of the engine fiy wheel 9. 10 is a coiled spring in a bearing bracket 11 attached to the bearing 6 and adapted (as it is compressed between the bracket end and the end of the shaft) to force the armature endwise out of the field a sufficient distance to throw the pinion 7 out of engagement with the fly wheelv gear 8. 12 is an elongated commutator having brushes 14, 15. 16 is a storage battery, 17 a circuit closing switch and 18 .and 19 are connections arranged to place the battery in series with the brushes, armature and field windings.

It will be seen that so long as the switch 17 is open the coil spring 10 will force the armature 4 endwise out of line with the field poles 2 and 3 so that the gears 7 and 8 will be out of engagement as shown in Fig. 1.

Upon closing the switch 17, as shown in Fig. 2, a heavy current will at first flow from the battery through the armature and field coils, thus powerfully magnetizing the field poles and causing the latter to exert a powerful horizontal attraction or pull on the armature 4. While in the displaced position shown in Fig. 1 the field will not exert its maximum rotative effect upon the armature which will thus at first be moved rapidly in an axial direction, but with less than maximum rotative effort owing to the then reduced area of the effective magnetic eld.

The rotation being in the same direction as which the field exerts upon the armature to draw it into its normal running position in ilo line with the field magnet poles and it will then exert its maximum torque to start the engine. Of course the spring will always exert a pressure and the armature can never reach exact alinement; at very least there will always be a slightV displacement diiiicult to be shown in the drawing.

After the first few explosions in the engine cylinders the fly wheel will gain in speed and drive the armature until the speed of the latter becomes so high that its counter electromotive force will so diminish the current passing through the motor that there will not be suiiicient magnetic attraction to hold the armature against the pressure of the spring 10 and the added outward thrust due to the angularity of the helical gear teeth when the motor is driven by the engine. As will be understood the` end thrust due to the angularity of the teeth is then reversed and the pinion underthe influence of the spring and of the inclined teeth will be moved horizontally out of engagement with the iiy wheel gear after which the operator opens the switch 17 and the motor comes to rest in position shown in Fig. 1. This helical form of teeth is in some cases desirable but is not essential to the.

successful-operation of the invention.

It will thus be seen that I have avoided the use of all gear shifting mechanism and that by the simple closing of the switch the armature is automatically thrown into engagement with the gear on the engine wheel and after coming into full engagement the maximum effort will be imparted to the` wheel to cause it to revolve. rihe particular arrangement is desirable for the reason given but it will be understood that my device is subject to various modifications without departing from the spirit of the invention.

Having described my invention, 1 claim.

1. An engine starting electric motor comprising a field magnet and an armature axially movable with respect to the eld and normaliy displaced but adapted to be brought into driving relationwith a device to be started thereby, an automatic means for restoring the movable armature to its normal displaced position, said means being dependent upon the increased counterelectromotive force developed when the speed is increased through starting of the device.

2. An apparatus of the class described comprising in combination, an engine starting electric motor comprising a field magnet and an armature axially movable with respect to said field and adapted to be brought into driving relation with adevice to be started thereby, together with means for restoring the armature to its normal displaced position when the motor has reached a predetermined speed.

3. In an apparatus of the class described when excited by the normal working current and to overcome the attraction of the field upon the armature when the current is reduced by action of the increased counterelectromotive force due to increased speed of the motor when-the starting of the device is effected.

4:. An electric starting motor comprising afield magnet and an armature arranged to have considerable axial movement within the field, in combination with means for engaging the motor with the device to be started through the agency of the axial movement of the armature and to be actuated by the motor current, and being so arranged that after the device has reached a predetermined speed the resultant decrease in the current passing through the motor will cause the automatic disengagement of the motor from the device.

5. An electric starting motor comprising a field magnet and an armature arranged to have considerable axial movement within the field, in combination with helical gears for engaging the motor with the device to be started through the agency of the axial movement of the armature and to be actuated by the motor current, and being so arranged that after the device has reached al predetermined speed the resultant decrease in the current passing through the motor will cause the automatic disengagement of the motor from the device.

6. In starting gearing for automobiles the combination of helical gear adapted to mesh with'each other and transmit motion from a starting motor to the automobile engine, one of said gears being shiftable axially out of operative position by the end thrust so 'i caused by the helical form of the gear teeth 1s frutas@ Y.7aiallrrelatreitthe @engagement therewith Vof the gear teeth beingsuchr-fthtsftm endA isrotated' by the starting motor and will in ,th

ggearinr fo automobiles Ceai'bmaaon zheircaingamaadapted an.

mesh withreach other and transmielimotibn:

fand the inclinato thrust thereon tendsltligolld.theaxially mov able gear whenlit?Zisirotatedrbyithe starting motor in engagement with the other gear and will shift it out of engagement therewith when it is rotated by the engine, and means vfor shifting said axially movable gear into engagement with'the other gear at will.

'9. In an apparatus of the class described, in combination, an internal combustion engine, an electric motor, a'helical gear operatively connected to said engine, a second helical gear adapted to mesh with said irst gear and normally disposed offset in an axial direction from its meshing position, and means for moving said second gear endwise into mesh with said first gear, said means comprising an endwise movable member coaxial with said motor and secured. to said second gear, said member being moved endwise solely by solenoid action when said motor is energized, said gears being automatically disengaged as the motor ceases to drive the engine when the starting of the engine has been effected.

10. In apparatus of the class described, the combination of an internal combustion engine, an electric motor, a helical gear operatively connected to said engine, a second helical gear adapted to mesh with said first gear and normally disposed offset in an axial direction from its meshing position, and means for moving saidl second gear into mesh by solenoid action upon the closing of the motor circuit and the starting of the motor, the pitch of the gear teeth being such that the axial thrust thereon hold the shiftable gear in operative position when it is rotated by the starting motor and will shift it into inoperative position when it is rotated by the engine. Y

1l. In an apparatus ofthe class described, the combination of an internal combustion engine, an electric motor, a source of power, circuit connections whereby said motor may be energized from said source of power, a helical gear connected to said engine, a helical gear connected to said motor and normally oii'set in an axial direction from meshing position, means adapted to automatically move saidsecond gear axially into driving engagement with said rst gear byy if itlintefinoperative;*position when rit yz-gtheengmaraudimeansiforfshifts ovableigear t safidncireu will tend toto mesh?- pull upon the closing of it; cennectipnsmthe freturn axial @second Y.gear beinaseted he restrictionpf` the (magnetic, pull,

an axial magnetic ter-electrqmotiyeg-force the; @malsaine been @A131 blues/trui? e Sad l" i ,-1231 appar Athe c om riallatalidirist stevent position, a shaft for'rotating v'said second gear, a source of current, and electro-magnetic means adapted when energized to move said second gear axially into mesh with said rst gear and to rotate said shaft, the return axial movement of said' second gear being effected upon the starting o'f the engine under its own power by the combined actions of decreased axial pull of said electro-magnetic means due to increased counter-electromotive force, the axial thrust of said helical gears and the tension of said springs.

13. Starting mechanism for internal combustion engines, including, in combination, helical gears adapted to mesh with each other and transmit motion from a starting motor to the engine, one of said gears being movable axially relative to the other into and out of engagement therewith, and the inclination of the gear teeth being such that the end thrust thereon tends to hold the axially movable gear in engagement with the other gear when it is rotated by the starting motor and will shift it,.out of engagement therewith when it is rotated by the engine, and means for automatically and electrically shifting said axially movable gear into engagement with the other gear upon the energizing of the motor. 14. In an apparatus of the class described 1n gine, an electric motor, a source of current, means for energizing said motor from said source of current, a gear operatively connected to said engine, a second gear adapted with said first gear and normally disposedyset in an axial direction from its meshing position, andmeans comprising a longitudinally movable shaft upon which said second gear is mounted, actuated by the motor in starting to move said second gear by said longitudinal movement in an axial direction into mesh -with said first gear to effect driving connection between said motor and said engine,said last mentioned means being adapted to automatically disengave the gears as the motor ceases to drive tlie engine, due to the increased counter-electro motive'force of the motor when the starting of the engine has been effected.

*11oI combination, an internal combustion en- `With Sald rst gear and normally disposed,`

Y 1 oset in an axialdirection from 4its meshing jf" '*position7 *and-F means i `10mounted'ffor rotary/aand'longitudinal move- "mprisingl a shaft,

' two y subscribing Witnesses. "'`{ment/,"Y adapted to automatically-move saidV i @second gear? larifaxial f' direction into' meslrl Y"fwith"Said.;fiit gar5'said' means being actuated by vthe lnovementof thearmature of said motor due to its attraction by theeld 15 magnet, and adapted to automatlcally dis- 1 engage the gearupon the decrease 1n pull of said field magnets due 'to thev increased counter-electromotive `force ofthe motor 4 *When the startinglof the engine has been 29 eected.

` In `testimony whereof I have signed my name tothis specification in the presence of K SAMUELNV. RUSHMORE. `VyVitness'es:

ZR. MILLWARD, ff

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