US1433833A - mcgrath - Google Patents

Description

W. L. MCGBAT ENGINE STARTER.

APPLICATION FILED WAR. 1. 1919.

Patented Oct. 31, 1922.

2 SHEETSSHEET 1 w. L. McGRATH. ENGINE STARTER.

APPLICATION FILED MAR. 1,19I9- Patented Oct. 31, 1922.

2 SHEETS SHEET 2| JAQ,

Patented Oct. 31, 1922. I 1,433,833 UNITED STATES PATENT OFFICE.

WILLIAM L. MCGRATH, OF ELMIRA, NEW YORK, ASSIG'NOR TO ECLIPSE MACHINE COMPANY, OF ELMIRA, NEW YORK, A CORPORATION OF NE\V YORK.

ENGINE STARTER.

Application filed March 1, 1919. Serial No. 279,982.

To allevizowz-it may concern: starting motor A, a driving head 2 secured Be it known that I, VVILLIAM L. Mcto the. outer end of the driving shaft, :1

GRATH, a citizen of the United States, residcoiled driving spring secured to a screw ing at Elmira. in the county of Chemung' shaft 4: which is in the form of a hollow 5 and State of New York, have invented cersleeve mounted on the driving shaft, a p1ni tain new and useful Improvements in Enion screw threaded. upon the screw threads gine Starters, of which the following is :i l of such shaft and adapted to mesh with specification. the teeth (3 of the lily wheel 6 or otherengine luv invention relates to starters for interdriven member.

10 nal combustion engines or the like, and the The stop nut 7 instead of being an ordi- 6 particular object thereof is to improve the nary collar secured to one end of a screw drive or transmission thereof. The drive shaftto form an abutment or stop for the with which my invention is concerned is pinion is provided with a cylindrical exof the automatic screw shaft type charactertension 7 projecting towards the pinion.

ized by a rotatable screw shaft driven by This stop nut is secured to the screw shaft 70 a starting motor and having screw-threaded .in any suitable manner as by means of thereon a pinion adapted to be automatically threading. The pinion is provided with :1 advanced into mesh with an engine driven central bore which is screw-threaded for member such as the fly wheel, by the rotation a portion of its length to loosely fit the of such screw shaft. This pinion loosely screw threads on the shaft, and is counter 75 threaded upon the screw shaft so that it will bored at 5 for a portion of its length, not be inclined to bind thereon at the time which counterbore is of a diameter to rather when the pinion is to be rotarily idle and accurately fit the cylindrical extension for to be advanced longitudinally as abov the purpose of centering the pinion at the 2 stated. When the pinion is in full mesh will: end of its longitudinal movement for mesht0 the fly wheel it is desirable that such pinion ing, and also of Running a solid and conshall be accurately centered on the. shaft and tiinuous support for such pinion during its shall be firmly supported thereby, in order rotation when driving the fly wheel. By to properly mesh with the fly wheel and preference the outer corner of the cylindrialso to avoid noise during their rotary movecal extension is inclined or beveled at 7 L- ment as well as to prevent wear between the to assist the pinion in the centering operapinion and the screw shaft. According to tion. The relative length of this extension my present invention I attain this object and counter-bore are such that at the end ofv by providing at one end of the screw shaft its longitudinal movement to the left the end a part (integral or separate from the shaft) of the pinion will abut against the annular 90 which accurately fits a plain counterborod shoulder 7 of the stop nut which thus re- )ortion of the central bore of the pinion. ceives all of the stopping contact and pros The invention may be embodied in different sure of the pinion.

forms of constructions, several of which are According to the modification shown in herein shown and described. Fig. 5, the centering means is an integral i" In the drawin Fig. l is a sectional plan part of the screw shaft itself, comprising of a starter inclu ing a drive embodying my plain portion 49 of suitable diameter which invention; Figs. 2 and 3 sections on the means the same or larger diameter than the line 2--2, 33 of Fig. 1; 4: a detail outside diameter of the screw threads l,

view in elevation of the stop nut and sleeve but, in the present instance, of slightly and a portion of the screw shaft; Figs. 5', larger diameter. The counterbore 5 of the (3 and 7 detail sections of modifications of pinion fits over this portion 49 in the same the same general type; Fig. 8 a sectional way and with the same results as in the case elevation of a modification of another type, of the other form of construction. In this 50 and Fig. 9 a section on the line 99 of construction, the stop shoulder 4. is integral Fig. 8. with. the shaft but obviously be formed Referring to the embodiment of my invenby a separate nut, like nut 7 as shown in tion as shown in Figs. 1 to 4, the drive llllli Fig. 6. In Fig. 7 I have shown another tinted comprises a driving shaft 1 which modification ol thc same general type as may be the extended armature shail of a above described but difiering from that of 1.

Fig. l in that the stop nut 8 is of plain form. The centering and supporting means is a plain ring 9 interposed between said nut and the end of the screw threads at. This particular construction has the advantage of economy and facility in manufacture inasmuch as the ring, being separate, can be separately machined or ground and treated.

By means oi: my invention 1 am enabled to obtain the advantage of a loose fit be ween the threads of the screw shaft and the pinion and to provide for .;he proper positioning and support of such pinion during the time when it is in driving: operation.

in l 8 and I have shown a modified construction of? a somewhat diilerent type ot drive according); to which the pinion is not sciew-threaded on a shaft but controlled in its operation by a nut or control member which is screw-threaded onto such shaft. lleierring to .l ig. S, the motor has an. extended. armature shaft which consists of a plain portion 10 and a screw-threeded portion 1.1. The pinion 12 slides on said. plain portion and is controlled by the nut 13 which is screw-threaded on said, screw shaft and is connected. to the pinion by the driving spring let. i

' As shown the pinion does not fit the outer end oi the plain portion of the shaft with any accuracy or closeness but has a loose fit therewith when in its. normal or home position thereby leaving an annular space 17 be tween the pinion and the shaft 10, as illustrated. However, the inner portion o't this shaft is slightly enlarged in diameter and carefully machined so that the pinion here will. fit accurately thereon when it is in mesh with the fly wheel. This enlarged portion is indicated at 10 and the result thereof is substantially the same with respect to the action of this pinion as inrespect to the pinions oil? the previously described constructions.

I claim:

1. In an engine starter a drive or transmission including a screw shaft a driving member scrcw-threaded thereon iior longitudinal movement along the shaft to engage a member oi the engine to be started, and a stop nut secured to the screw shaft and having an extension projecting; towards the driving men'iber, which latter has a countew bore adapted to lit upon. such. extension.

2. In an engine starter, a drive or trans mission including :1 screw shaft. a driving:

member screw-threeded thereon itor loniritudinal movement along the shai l; to engage u member 01 the engine to be sinrted. and a stop nut secured to the screw shziitt and he inn i1 cylindrical extension ol' less dimneter than the nut. such driving member having: :1 counteirbore adapted to [it upon the sleeve.

in an engine starter, a drive or transmission including :i screw shaft, a drivimz member screw-tlneaded thereon :tor longitudinal movement along the shaft to engage a n'ieinber oi the engine to be started, and a stop nut secured to the screw shaft end having an extension projecting towards the driving member which has a counterbore adapted to [it upon such extension, the outer corner oi said extension being shaped to insure centering; oi the driving; member.

at. In an engine starter, a drive or-trans mission including;- a screw shaft. a driving; member screw threaded thereon for longitudinal IDUYQHlQH Z along the shaft to engage a member oi the engine to be started, and a stop nut secured to the screw shaft and having an extension projecting towards the driving member, which has a countei'bore adapted to fit such extension, said counterbore heir longer than the entensicn to permit the driving);' member to abut the stop nut itself. I

ll lz ihliih'l L. lvioGl-iilti.

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