US1952645A

US1952645A - Starter gearing

Info

Publication number: US1952645A
Application number: US606743A
Authority: US
Inventors: Maurice P Whitney
Original assignee: Eclipse Machine Co
Current assignee: Eclipse Machine Co
Priority date: 1932-04-21
Filing date: 1932-04-21
Publication date: 1934-03-27
Anticipated expiration: 1951-03-27

Description

March 27, 1934.

M. P. WHITNEY 1,952,645

STARTER GEARING Filed April 21, 1932 2 Sheets-Sheet 1 I 11v VENTOR fi m Es: v r B Y 6 M A TTORNEY March 27, 1934. p. wHlTNEY I 1,952,645

STARTER GEARING Q Filed April 21, 1932 2 Sheets-Sheet 2 3% 4 (NVENTOR Tflaur' Pw/u'tney hV/rmsssx [0d] I A OR/VEY Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE STARTER GEARING Application April 21, 1932, Serial No. 606,743

18 Claims.

The present invention relates to starter gearing. and more particularly to a starter drive of the type in which a pinion is automatically traversed into and out of engagement with an engine member.

The development of small bore multi-cylinder automotive engines and of lower car bodies and engine mountings have contributed to the tendency to decrease the size of engine flywheels. At

the same time the high compression ratios now used require high cranking torque so that if a small starting motor is to be used, a high gear reduction to the engine flywheel is necessary.

It is an object of the present invention to provide a novel drive of this type which is small and compact and permits the use of a starter pinion of small diameter whereby a suitable gear reduction may be used with a small flywheel gear.

Another object is to provide such a device 'in- 0 cluding a yielding driving connection which is small and light in construction while being amply strong to transmit the required torque.

Another object is to provide such a device embodying novel provisions for enforcing meshing of the pinion with the flywheel gear in case a. tooth of the pinion should abut end to end with a tooth of the gear.

A further object is to provide such a device embodying novel provisions for preventing rebounding of the pinion toward the engine gear when it is thrown out of mesh as the engine starts.

Another object is to provide such a device having novel provisions for preventing the pinion from drifting away from its idle position while the engine is running.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a. side elevation partly in section of a preferred embodiment of the invention showing the parts in normal or idle position;

Fig. 2 is a similar view showing the parts in driving position;

Fig. 3 is a similar view showing the parts in the positions assumed when a pinion tooth abuts tooth of the flywheel gear;

Fig. 4 is a side elevation partly in section of a hollow screw shaft to be attached to a power 50 shaft;

Fig. 5 is a similar view of a nut member to threaded thereon;

Fig. 6 is an end view of the nut member shown in Fig. 5;

Fig. 7 is a side elevation partly in section of a nut member to be threaded on the first nut member;

Fig. 8 is an end view of the second nut member;

Fig. 9 is a detail of a spring member operative to insure initial threaded engagement of the screw shaft and first nut member; and

Fig. 10 is a section of said spring member taken substantially on the line 1010 of Fig. 9.

Referring first to Fig. 1 of the drawings, there is illustrated an engine starter drive including a power shaft 1 which may be the extended armature shaft of a starting motor not shown. A driving member in the form of a pinion 2 is journalled on the power shaft 1 with freedom for longitudinal movement into and out of meshing engagement with a member of an engine to be startedsuch as a flywheel gear 3.

Means are provided for traversing the pinion 2 into and out of engagement with the engine gear 3 and for rotating said pinion including two inclined connections in series. The first inclined connection includes a hollow shaft 4' provided with threads 5 for a portion of its length (Fig.

4) suitably fixed to the power shaft 1 as by means of the key 6 and a stud 7 threaded into a collar 8 mounted on the, end of the screw shaft; and a nut member 9 mounted on the hollow shaft 4 and provided with internal threads 11- adapted to cooperate with the threads 5 on said shaft. Stop means in the form of shoulders 12 are provided on said shaft for limiting longitudinal motion of the nut member 9 thereon in one direction, and the collar 8"serves to limit motion thereof in the opposite direction. The threads 5 terminate a sufficient distance from the collar 8 to allow the nut to run off said threads and rotate freely on the smooth portion of shaft 4 adjacent the collar 8.

Means are provided for normally retaining the nut 9 in its idle position on said smooth portion of shaft 4 as indicated in Fig. 1. As there shown, this means takes the form of a light spring 13 arranged to hear at one end against said nut member and at the other end against an abutment ring 14 seated against a shoulder 15 adja- 10o cent the end of the shaft 4. The

shoulders

12 and 15 on shaft 4 are preferably provided by forming said shaft with stepped portions as indicated in dotted lines in Fig.- 4 before the threads 5 are hobbed on said shaft.

The second inclined connection includes a second nut member 16 arranged to be threaded on the first nut member with a comparatively steeply pitched thread as best shown in Figs. 5 and 7, the external threadon the nut 9 being indicated 110 at 17 and the internal thread in the nut 16 being indicated at 18.

In order to complete the traversing and rotating connection between the shaft 1 and pinion 2, nut member 16 is slidably mounted in a barrel or shell member 19 as by means of radial lugs 21 on said nut member engaging the slots 22 of said shell; and the shell 19 is fixed to the pinion 2 at one end as by means of inwardly extending lugs 23 adapted to fit between the rear ends of the pinion teeth and suitably held in position as by spinning over the hubof the pinion as indicated at 24. The opposite end of the shell 19 is closed by means of a cap 25 threaded thereto as indicated at 26 and forming an abutment for the

nut members

9 and 16.

Means are provided for cooperating with the second inclined connection to provide a yielding driving connection to the pinion in the form of a spring 27 hearing against the nut member 16 at one end and against the front end 28 of the shell 19, whereby the shifting movement of said second inclined connection is yieldably limited and said nut member is normally retained at the rearward limit of its travel in the shell 19 against the cap 25. A cushioning element 29 may be provided within the cap 25 if so desired in order to render the operation of the device more quiet.

Means are provided for ensuring engagement of the shifting connection on actuation of the power shaft by urging the inner nut member 9 into initial engagement with the threads 5. As here shown, this means is in the form of an elastic spider 31 (Figs. 9 and 10) which is arranged to be loosely mounted on the shaft 4 within the shell 19 adjacent the end of the hollow shaft 4. The spider 31 is provided with resilient arms 32 adapted to bear against the end 28 of the shell 19 when the parts are in idle position as shown in Fig. 1 and thereby cause the cap 25 of said shell to urge the nut member 9 against the ends of the threads 5.

In the operation of the device, starting with the parts in the positions shown in Fig. 1, rotation of the power shaft 1 in the direction of the arrow causes the inner nut member 9 to enter the threads 5 on the hollow shaft 4 and to be traversed thereby by reason of its inertia and the inertia of the parts associated therewith, until the end of said nut member engages the stop shoulders 12 on said shaft. The entire pinion assembly including the

nut members

9 and 16, the shell 19 and pinion 2 is thus shifted longitudinally until the pinion 2 is meshed with the flywheel gear 3, this meshing position being defined by the shoulders 12 on the hollow shaft 4 as illustrated in Fig. 2. Further rotation of the power shaft 1 is transmitted directly to the inner nut member 9 and through the

inclined connection

17, 18 to the outer nut member 16. The spring member 27 cooperates with said inclined connection to form a yielding driving connection with the pinion through the

splined connection

21, 22 to the shell 19 fixed to said pinion, whereby the engine member 3 is rotated to crank the engine.

When the engine starts, the acceleration of the flywheel gear 3 is transmitted to the pinion 2 causing the

nut members

16 and 9 to overrun the hollow shaft 4. whereby'the nut member 9 is traversed back to its idle position, carrying the pinion assembly therewith by virtue of its engagement with the cap 25. When the nut 9 reaches its idle position it runs off the ends of the threads 5, thereupon rotating freely on the smooth portion of the shaft 4. Rebounding of the pinion toward the engine gear by reason of impact when thrown out of mesh therewith is thus efiectively prevented. The

engaging surfaces

33 and 34 on said nut member and on the collar 8 are preferably inclined at such an angle as to create suitable friction upon the engagement thereof to dissipate the momentum of the pinion assembly. When the spinning of the pinion assembly has ceased, the spider 31 functions to hold the nut member 9 against the ends of the threads 5 and causes proper engagement with said threads upon actuation of the power shaft 1 as previously described.

If during the meshing movement of the pinion 2 a tooth thereof should abut end to end with a tooth of the flywheel gear 3, longitudinal movement of the pinion 2 and outer nut member 16 is obstructed. Under these circumstances further longitudinal movement of the inner nut member 9 causes the second inclined connection to cooperate with the shell 19 to provide means for indexing the pinion. In this operation the outer nut member 16 is rotated slightly due to the

high pitch threads

17, 18 and this rotation is transmitted through the shell 19 to index the pinion 2 into proper registry with the teeth of the flywheel gear, whereupon meshing and cranking take place as usual.

It will be noted that during this indexing action, the pinion 2 is pressed against the flywheel gear 3 by the spring 27 which is compressed by the longitudinal component of the forces applied to the outer nut member 16 from the inner nut 9 as indicated in Fig. 3. This compression of the spring 27 causes the pinion 2 to be snapped into initial engagement with the flywheel gear as soon as proper registry takes place, whereby the possibility of a milling action of the pinion teeth on the flywheel gear is prevented. It will be noted that by reason of the steep inclination of the

outer threads

17, 18, the indexing action as above descr bed will take place without the necessity of building up a heavy longitudinal pressure. It W111 also be understood that this same feature allows the use of a comparatively small and light spring 27 since the longitudinal component of the cranking torque transmitted through said inclined connection is comparatively small.

Although but one embodiment of this inven t10n has been shown and described in detail, it will be understood that various changes may be made in the construction and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an engine starter drive a power shaft, a driving member, means for shifting and rotating said driving member from said shaft including a first inclined-connection, a second inclined connection including longitudinally movable members between the driving member and the first inclined connection, and means whereby obstruction of the longitudinal movement of the driving member during the shifting movement of the first inclined connection causes relative movement of the elements of said second inclined connection to index the driving member.

2. In an engine starter, drive, a power shaft, a driving member, means for shifting and rotating said driving member from said shaft including a first inclined connection, a second inclined connection including a pair of longitudinally movable elements in series therewith, and means connecting one of the elements of said second inclined connection to said driving member whereby obstruction of the meshing movement of the driving member restricts the longitudinal movement of said element, and further shifting movement of the cooperating element of the second inclined connection by the first inclined connection causes indexing of thefirst mentioned element and said driving member.

3. In an engine starter drive, a power shaft, a driving member slidably journalled thereon and means for traversing and rotating said driving member from said shaft including a member connected with said shaft for automatic traversal thereon toward a member of an engine to be started, a second member so connected with said first member that relative longitudinal movement causes relative rotation therebetween, means connecting said driving member to said second member for rotation therewith and yielding means for opposing relative longitudinal movement of said second member and driving member.

4. In an engine starter drive, a power shaft, a driving member journalled thereon, means for automatically traversing the driving member into and out of engagement with a member of an engine to be started including an inclined connection of relatively low pitch and a yielding driving connection for rotating the pinion from the shaft including an inclined connection of relatively high pitch.

5. In an engine starter drive, a power shaft, a driving member journalled thereon, means for automatically traversing the driving member into and out of engagement with a member of an engine to be started including an inclined connection of relatively low pitch and means for positively limiting relative longitudinal movement of the parts thereof in the engaging direction, and a yielding driving connection for rotating the pinion from the shaft including an inclined connection of relatively high pitch and means for yieldingly limiting relative longitudinal movement of the parts thereof in the'driving direc-' tion.

6. In an engine starter drive, a power shaft, a driving member slidably journalled thereon and means for traversing and rotating said driving member from said shaft including a nut member having a threaded connection with said shaft of a relatively low pitch, a second nut member having a threaded connection to the first nut member of relatively high pitch, and means for transmitting longitudinal movement and rotary movement from the second nut member to said driving member.

7. In an engine starter drive, a power shaft, 9.

'- driving member slidably journalled thereon and means for traversing and rotating -said driving member from said shaft including a nut member having a threaded connection with said shaft of a relatively low pitch and a stop for positively limiting longitudinal movement of the nut on said shaft in one direction, a second nut member having a threaded connection to the first nut member of relatively high pitch and yielding means for opposing longitudinal movement of said second nut on the first nut.

8. In an engine starter drive, a power shaft, a driving member, means for shifting said driving member into and out of engagement with an engine member and for rotating said driving member to crank said engine including/two inclined connections in series, one of said connec-- tions operating through the other connection to shift the driving member and being automatically disconnectable to allow the driving member to overrun.

9. In an engine starter drive, a power shaft, a driving member, means for shifting said driving member into and out of engagement with an engine member and for rotating said driving member to crank said engine including two inclined connections in series, one of said connections operating through the other connection to shift the driving member and being automatically disconnectable to allow the driving member to overrun and means for insuring reengagement of said shifting connection on reactuation of the power shaft.

10. In an engine starter drive, a power shaft, a driving member, means for shifting said driving member into and out of engagement with an engine member and for rotating said driving member to crank said engine including two inclined connections in series, one of said connections operating through the other connection to shift the driving member and being automatically disconnectable to allow the drivingmember to overrun and resilient means cooperating with said other inclined connection to form a yielding driving connection to said driving member.

11. An engine starter drive including a shaft, a pinion mounted thereon for movement into and out of mesh with an engine gear, a member having a splined connection with the pinion, yielding means for transmitting meshing movement from said member to said pinion, a cooperating member having an inclined connection with said first member such that relative longitudinal movement causes relative rotation therebetween, means for moving said cooperating member longitudinally in a direction to mesh the pinion and for thereafter rotating the same, said yielding means cooperating with said inclined connection to form a yielding driving connection for said pinion.

12. An engine starter drive including a shaft, a pinion'mounted thereon for movement into and out of mesh with an engine gear, a member having a splined connection with the pinion, a yielding means for transmitting meshing movement from said member to said pinion, a cooperating member having an inclined connection with said first member such that relative longitudinal movement causes relative rotation therebetween, means for moving said cooperating member longitudinally in a direction to mesh the pinion and for thereafter rotating the same, said yielding means cooperating with said inclined connection to form a yielding driving connection from said pinion, said inclined connection being so formed that obstruction of the meshing movement of the pinion causes the second member to rotate the first member while pressing it longitudinally against said yielding means.

13. In an engine starter drive, a power shaft, a pinion, means for shifting said pinion into and out of mesh with an engine gear and for rotating said pinion to crank said engine including a nut member having a threaded connection to said shaft, a second member having an inclined connection with the nut member of a comparatively high pitch, a shifting and driving connection between said second member and said pinion, said nut member being arranged to shift the second member to move the pinion into and out of mesh with the engine gear and to rotate said second member to index said pinion by virtue I 14. In an engine starter drive, a power shaft, a pinion, means for shifting said pinion into and out of mesh with an engine gear, andfor rotating said pinion to crank said engine including a nut member having a threaded connection to said shaft, a second member having an inclined connection with the nut member of a comparatively high pitch, a shifting and driving connection between said second member and said pinion, said nut member being arranged to shift the second member to move the pinion into and out of mesh with the engine gear and to rotate said second member to index said pinion by virtue of said inclined connection in case of tooth abutment between said pinion and gear, said nut member being arranged to run off its threaded connection and allow the pinion to overrun after being returned to its idle position.

15. In an engine starter drive, a power shaft, a pinion journalled directly thereon and adapted to engage and drive a gear of an engine to be started, means actuated by said power member for shifting said pinion into driving position and thereafter forming a positive rotary connection in the line of drive'to said pinion, said shifting and connecting means including means interposed between the positive rotary connection and the pinion for indexing said pinion in case of tooth abutment with the engine gear, and means cooperating with said indexing means to form a yielding rotary connection in said line of drive.

16. An engine starter drive including a power shaft, a pinion freely journalled thereon for longitudinal movement into and out of mesh with an engine gear, a nut having a threaded connection with said shaft, a shifting and driving connection from said nut to said pinion, means limiting the travel of said nut in a direction to mem the pinion, said threaded connection terminating at a point just short of the idle position of said nut, and yielding means urging said nut into initial threaded relation with said shaft.

17. An engine starter drive including a power shaft, a pinion freely journalled thereon for longitudinal movement into and out of mesh with an engine gear, a nut having a threaded connection with said shaft, a shifting and driving connection from said nut to said pinion, means limiting the travel of said nut in a direction to mesh the pinion, said shifting and driving connection including a second nut member threaded to the first nut member with a relatively high pitch thread whereby longitudinal movement of the first nut member relatively thereto causes indexing of said second nut and pinion. I

18. An engine starter drive including a power shaft, a pinion freely journalled thereon for longitudinal movement into and out of mesh with an engine gear, a nut having'a threaded connection with said shaft, a shifting and driving connection from said nut to said pinion, means limiting the travel of said nut in a direction to mesh the pinion, said shifting and driving connection including a second nut member threaded to the first nut member with a relatively high pitch thread, and means for yieldingly resisting longitudinal movement of the second nut member when the pinion is in driving position and cooperating therewith to form a yielding driving connection for the pinion.

MAURICE P. WHITNEY.