US1705252A - Starter for engines - Google Patents

Description

March 12, 1929. M. B. JACKSON STARTER FOR ENGINES 4 Sheets-Sheet Filed Dec. 10, 1926 W Z m V. 0 R EV m mm wfiww a MR 0 o mw m w O Q w @w Q. WW 0 m h w M 0 an N \X Q M fi FEE:

March 12, 1929. M. B. JACKSON 1,705,252

STARTER FOR ENGINES Filed Dec. 10, 1926 4 Sheets-Sheet 3 QNN QVN \N. Q I a e3 m.

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Mud! 1929- M. B. JACKSON STARTER FOR ENGINES Filed Dec. 10, 1926 4 Sheets-Sheet 3 QNN March 12, 1929. B, JACKSON s'rmrna FOR suenms Filed Dec. 10, 1926 4 Sheets-@heet 4 simww Patented Mar. 12, 1929.

UNITED STATES MAUNSELL BOWERS JAGKSON, OF TORONTO, ONTARIO, CANADA.

STARTER FOR. ENGINES.

Application filed December 10, 1926.

This invention relates to starters for internal combustion engines of the type employing a motor driven pinion adapted to be axially moved into meshing engagement with a gear of the engine and adapted to be automatically de-meshed when the engine starts and my object to provide simple and ellicient means for causing such axial movement of the pinion and for causing a rotary movement thereof as may bc necessary to aline it with the gear without damaging the teeth of the pinion or gear. Another object is to devise means for using parts of the motor as a switch so that the motor may be energized, without the use of a separate switch, when the pinion is meshed with the gear.

I attain my objects by means of the constructions briefly described as follows. On an axially movable member. which may be a shaft or a sleeve on a shaft, is mounted the pinion. The pinion adapted to be carried by the axially movable member towards the engine gear and into mesh therewith if the teeth on the pinion are in alinement with the spaces between the teeth on. the gear. If the pinion teeth meet end to end with the gear teeth the axial movement of the pinion will be temporarily stopped but the axial movement of the member will continue and this movement is adapted to cause the pinion to be rotated relative to the member until its teeth clear the teeth of the gear. The axial n'iovement of the pinion is then continued until it in meshing engagement with the gear. The member may be axially moved either manually by manually operable means, or automatically by means of a shaft having the member threaded thereon. The constructions are hereinafter described more fully and illustrated in the accompanying drawin gs in which Fig. 1 is a longitudinal section of my starter showing the parts thereof in their normal or inoperative position;

2 a section showing the parts in their operative positions;

Fig. 3 a section showing the parts as they are positioned after the engine has started and before the operator has removed his foot from the starter plunger;

Fig. 4 a section of a modified form of the starter showing the parts thereof in their inoperative position;

Fig. 5 a sectional detail of some of the parts shown in Fig. 4, the full lines indicating the Serial No. 153,846.

operative position of these parts and the dotted lines indicating the position of the pinion after the engine has started;

Fig. 6 a longitudinal section of a second modified form of the starter showing the parts thereof in their inoperative ositions;

Fig. 7 a sectional detail of some 0 the parts shown in Fig. 6 the full lines indicating the operative position of these parts and the dotted lines indicating the position of the pinion after the engine has started;

Fig. 8 a cross section on the line 88 in Fig. 7;

Fig. 9 a longitudinal section of a third modified form of my invention in which the member is threaded on the shaft, the parts being shown in their inoperative positions;

Fig. 10 a section similar to Fig. 9 showing the parts in their operative positions; and

Fig. 11 a sectional detail of some of the parts shown in Figs. 9 and 10 showing the position of the pinion after it has been demeshed by the gear and its axial movement stopped.

1n the drawings like numerals of reference indicate corresponding parts in the different figures.

Referring to Figs. 1 2 and 3, 1 is an electric motor provided with an extended armature shaft 2 having long pitched threads 3 formed thereon. The opposite ends of the shaft are slidably mounted in bearings 4i and 5. which are formed on or carried by the motor housing 6, so that the shaft may be axially moved. A collar 16 having a groove formed. therein is secured to the threaded end of the shaft :2.

A. lever 12 journalled on a stud 13 is adapted to be rocked by any suitable manually operable mechanism such as the foot pedal or plunger 14. The end of the lever remote from the foot pedal is pivotally connected with a rod 8 which provided with a forked arm 15 that is adapted to be received in the groove in the collar 16. The rod is slidably mounted in a bearing 10 carried by a housing 11. A spring 17 connected With the lever 12 and a suitable stationary part such as the housing 11 tends to maintain the armature shaft in its normal or inoperative position as shown in Fig. 1. In this position the commutator 18 on the armature shaft is out of engagement with the spring pressed brushes 19 whereby the circuit 20 for supplying energy to the motor 1 is open.

A pinion 21, threaded on the shaft threads 3, is adapted to be moved, as hereinafter described, into mesh with a gear 22 connected with the fly wheel of an engine (not shown). The axial movement of the pinion relative to the shaft in one direction is limited by a shoulder 23 carried by or formed on the shaft and in the opposite direction by the collar 16. A stationary abutment 24; is adapted to prevent the pinion from being carried along with the shaft 2 when the latter is permitted to move to its normal position.

Assuming the parts are positioned in their normal positions as indicated in Fig. 1, the mode of operation is as follows. The operator depresses the plunger 14 and rocks the lever 12 which axially moves the shaft 2 against the tension of the spring 17. The threads 3 engage the threads of the pinion 21 and carry the latter along with the shaft towards the engine gear 22. If the teeth on the pinion are in alinement with the spaces between the gear teeth the pinion will be meshed with the gear, and the commutator 18 will engage the brushes 19 to close the circuit 20 and thus energize the motor to rotate the gear. The axial movement of the shaft in its operative position is limited by a shoulder 25 formed on or carried by the rod 8 which is adapted to engage the housing 10' to prevent the brushes or their springs from being damaged.

Should the teeth of thepinion and gear meet end to end when the pinion is being axially moved into mesh with the gear, the axial movement of the pinion will be stopped. This does not interfere with the continuous axial movement of the shaft which movement causes the threads 3, as they are passed through the pinion, to rotate the latter until its teeth clear the gear teeth. The threads 3 then carry the pinion axially into meshing engagement with the gear which engagement temporarily prevents the pinion from rotating with the shaft when the commutator engages the brushes to energize the motor. l/Vhen the shaft is rotated the threads 3 cause the pinion tobe moved axially to mesh it fully with the gear. This movement is limited by the shoulder which causes the pinion to be rotated with the shaft to drive the gear. The driving or operative position of the parts is shown in Fig. 2.

When the engine is started the pinion is automatically d'e-meshed in the usual'man ner. This. movement of the pinion is shown in Fig. 3. and is limited by the collar 16 which has been moved with the shaft to a position in front of the abutment 24. This arrangement prevents the pinion, when it is being d e-meshed, from engaging the solid abutment which would have a tendency to cause the pinion to rebound therefrom.

The spring 17 returns the shaft to its inoperative position and thus opens the motor circuit 20 when the operator removes his foot from the pedal 14. lVhen the shaft is being returned, the return movement of the pinion is limited by the stationary abutment 24 as hereinbefore described. The spring also tends to hold the shoulder 23 in engagement with the pinion to limit the movement'of the latter in one direction and the movement of the pinion in theothcr direction is limited by the stationary abutment 24:, whereby the pinion is prevented from. contacting accidentally with the gear, while the engine is running, as shown in Fig. 1.

In t and 5 the armature shaft 2 of the motor 1 provided with a gear 26 which is constantly meshed by a gear 27 that is secured to an axially movablecountershaft 28. The latter is journalled in the bearings 4t and 5 and is provided with threads 3 and with shoulders 23 and 25 formed on opposite sides of a collar secured to the countershaft. A grooved collar 16 secured to the countershaft is engaged by the pins 15 on the manually operable lever 12; A spring 17 tends to hold the parts in their inoperative position as shown in Fig. 1. When the lever 12* is rocked by the manually operable plunger 14; the countershaft is axially moved to mesh the pinion 21 with the engine gear 22 in the same manner as the hereinbefore described meshing of the pinion 21 and gear 22. As the shoulder 25 nears the bearing 1*, the lever 12 is adapted to operate a spring pressed contact 29 of an ordinary plunger type switch to move it to close the starter motor circuit. The full lines in Fig. 5 indicate the driving or operative position of the parts, the movement thereof toward this position being limited by the spring pressed contact 29. The dotted lines in Fig. 5 indicate the d'e-ineshed position of the pinion in engagement with the collar 1 6 after the engine has started and before the operatorhas removed his foot from the plunger 14*. The pinion 21 normally held between the shoulder 28 and the stationary abutment 24? by means of the spring 17 which is connected with the lever 12 and a stationary part 11.

The second modification of my starter shown in Figs. 6, 7 and 8 employs the same principle of meshing the pinion 21 with the gear 22 as that previously described for meshing the pinions'21 and 21 with the gears 22 and 22" respectively. In this case the threads 3' are formed on an axially movable sleeve 28 which is provided with straight splines 30 slidable in keyways 31 formed in the armature shaft 2 which is driven by the motor 1*. The shoulders 25" and 23" are formed on opposite sides of a collar secured to the sleeve 28* and the abutment 24 is formed as an annular plate removably carried by means of screws 32 on the part 11. Vhen the plunger 14 depressed the pins 15", which engage the collar 16, move the sleeve axially of the shaft 2 to cause the threads 3 to carry the pinion towards the engine gear. The threads then rotate the pinion if necessary and then again axially move it into meshing engagement with the gear. The lever l2 operates the switch 29 to rotate the shaft and sleeve whereby the threi'ids 3 fully mesh the pinion and gear and then form a drive connection between the sleeve and the pinion when the latter engages the shoulder 23.

In Figs. 9, 10 and 11 the starter is of the in ertia type and the sleeve 28 is threaded on the threads or spiral splines 33 formed on the armature shaft 2. To enable a small sized pinion 21 to be used, the sleeve is provided with an extension mounted in a bearing 10 carried by the part 11. On the extension of the sleeve 28" are formed the threads 3 and the shoulder 23. The pin 21, threaded on the threads 3?, is normally in engagement with the abutment 24.", and is normally engaged by the shoulder 23" as in the previously described. arrangements of my starter.

Assuming the parts are in their normal or inoperative positions as shown in Fig. 9, the mode of operation is as follows. lVhen the operator closes the normally open switch 29 the motor is energized which causes the shaft 2" and threads 33 to rotate. The inertia of the sleeve 28 permits the shaft to rotate relative to it so that the sleeve is fed or axially moved along the rotating shaft 2 and the iii pinion 21 is carried towards the engine gear 22. The axial movement of the sleeve is continuous, until the bottom of the threaded recess in the sleeve engages the end of the shaft 2 to establish a rotary driving connection between these parts. teeth happen to be alined with the spaces be tween the gear teeth, the pinion will be axially moved or carried along by the threads 3 into mesh with the gear. If the pinion teeth abut the gear teeth, the axial movement of the pinion will be stopped. to permit the threads 3, as they pass through the pinion, to rotate it until its teeth clear the gear teeth. Thethreads 3 then carry the pinion axially again into meshing engagement with the gear and, when the rotary drive connection between the shaft and the sleeve is formed, the said threads cause the pinion to be threaded along the sleeve into engagement with the shoulder 23 to form a drive connection between the sleeve and the pinion as shown in Fig. 10.

The pinion is thus driven to drive the gear and when the engine is started the speed of the pinion relative to the speed of the shaft 2 is increased which causes the pinion and sleeve to be threaded along the threads 33 to return these parts to their normal position. Should the increased speed of the pinion cause it to be threaded along the threads 3 to de-mesh it from the gear, the axial part of this return movement of the pinion will be If the pinion stopped by a collar 34 carried by the extension of the sleeve 28 and the momentum of the pinion will be resolved into a rotary movement which will cause the sleeve 28 to be re tated at a greater speed than the speed of the shaft 2 whereby the sleeve will be returned to its normal position.

Referring again to Figs. 1, 2 and 3 it has been found in practice that if the pinion be engaged directly with a flat surfaced annular abutment 24, it has a tendency to remain in engagement with the abutment curing the next movement of the member 2 towards its operative position. To overcome this objectionable feature I may provide a two-piece washer 7 which is clamped by a light spring coil 9 on the threads 3. This washer is located behind the pinion, and normally between the pinion and the stationary abutment 24. While the spring ensures that the washer will move with the member, it also permits the washer to move with. the pinion relative to the member. Other ways of overcoming the above objectionable feature are by having a fairly tight fit between the threads of the pinion and thoseof the member and by forn'iing studs or projections 35 on the abutment as shown in Fig. 6. To prevent the armature shaft from spinning after the commutator 18 has been withdrawn from the brushes 19, a brake shoe 37 carried by the armature shalt 2 is adapted to engage a stationary brake ring 36.

It will be distinctly understood that the rin member in the claims is intended '1, include the axially movalile shafts 2 and 25?. and the axially movable Slfitflt 28 and 1 52, In all the arrangements of the rarter met anisrn, the member is carried substantially parallclto and in spaced relationship a" h the teeth of the gear and the axial movement of the member is continuous whether the pinion has to be rotated or not before it is meshed with the gear. hen the axial newment imparted by the threads 3, 3, 3 or to its pinion is resolved into a rotary n'ioveinent, these long pitched threads have no tendency to cause the pinion teeth to dig into tli teeth.

The reason for this that the th '1 s 3 are merely passed through the pinion to retate it instead of forming a rotary nection with the rotating screw shad as in the case of the hereinbcfore known inertia. starters of the Bendix type.

Vb at I claim is 1. An engine starter including an axially movable rotatable member; manually operable means adapted to move the member axially; a pinion adapted to be meshed with the gear of an engine to be started, the pinion being threaded on the said member, the thread being adapted to cause the pinion to be axially moved with the member to mesh the pinion with the gear and adapted to cause the pinion to be rotated during the axial movement of the member if the teeth on the pinion meet end to end with the teeth on the gear, the thread also being adapted to cause the pinion to be de-meshed automatically when it is driven by the engine gear; means adapted to limit the return axial movement of the pinion when it is (lo-meshed; and a stationary abi ment adapted to prevent the pinion from being carried along with the member when the latter is moved to its normal position. i

2. An engine starter including an axially movable rotatable member; manually operable means adapted to move the member axially; a pinion adapted to be meshed with a gear of an engine to be started; moans ineluding inclined plane connections between the member and the pinion, whereby the pinion is caused to be movec axially with the member to mesh the pinion with the engine gear and is causedto be rotated if the pinion teeth meet end to end with the teeth of the engine gear, the inclined plane connections also being adapted to cause the pinion to be de-meshed automatically when it is driven by the engine gear; a part carried by the member and adapted to limit the deshing movement of the pinion; and a sta onary abutment adapted to prevent the pinion from being carried along with the member when the latter moves to its normal position.

3. An engine starter including an ax lly movable rotatable member; means adapted to move the member axially; a pinion adapted to be meshed with a gear of an engine to l e started; means including inclined plane connections between the men her and the pinion, whereby the pinion is caused to be moved axially with the member to mesh the pinion with the engine gear and is caused to be rotated if the pinion teeth meet end to end with the teeth of the engine gear, the inclined plane connections also being adapted to cause the pinion to be de-meshed automatically when the engine starts; stationary means adaptedto limit the axial movement of the pinion in one direction to normally position the pinion at a predetermined distance from the gear; a shoulder on the member adapted to engage the side of the pinion remote from the said stationary means; and a spring tending to move the member axially to bring the shoulder into engagement with the pinion.

4. Engine starter apparatus comprising in combination, a motor provided with brushes; an axially movable armature shaft provided with a commutator normally out of engagement with the brushes; a pinion threaded on the shaft and adapted to be meshed with a gear of an engine to be started; and manually operable means adapted to move the shaft axially to carry the pinion into meshing engagement with the gear, the thread being adapted to rotate the pinion until its teeth clear the gear teeth should the pinion teeth meet end to end with the gear teeth, the said movement of the shaft being adapted to move the commutator into engagement with the brushes when the pinion is in meshing enga ement with the gear.

he starts apparatus comprising in tion a motor provided with brushes; i ially movable armature shaft provided wit '1 a commutator normally out of engagement with the brushes; a pinion threaded on the shaft and adaptel to be meshed with a gear of an engine to be started; manually operable means adapted to move the shaft axially to carry the pinion into meshing engagement with the gear, the thread being adapted to rotate the pinion until its teeth clear the teeth should the pinion teeth meetend to end with the gear teeth, the said movement of the shaft being adapted to move the commutator into e agement with the brushes when the pinion is in meshing engagement with the gear; and means ten ding to hold the commutater and the pinion out of engagement with the brushes a u the gen r respectively.

6, An engine starter including an axially movab e rotatable member; means adapted to more the member axially; a pinion adapted to be meshed with a gear of an engine to be started; means including inclined plane connections between the member and the pinion, whereby the pinion is caused to be moved axially with the member to mesh the pinion with the engine gear and is caused to be rotatod it the pinion teeth meet end to end with the teeth of the engine gear, the inclined plane connections also being adapted to cause the pinion to be de-meshed automatically when the engine starts a stationary abutment adapted to prevent the pinion from being carried along "it-.1 the member when the latter moves to its normal position; and a spring clamp carried by the memberand located between the pinion and the abutment to ensure the movement of the pinion towards the gear with the member and to permit the tie-moshing of the pinion.

Signed at Toronto, Canada, this 7th day of December, 1926. I

MAUNSELL B. JACKSON.

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