US1575698A - Engine starter - Google Patents

Description

March 9,1926 1,575,698

W. L. MCGRATH 4ENGINE STARTER" FildAugust 2, 1919 2 sheds-sheet 1 yMarch 9, 1926. '1,575,698

w. L. MCGRATH ENGINE STARTER yielding driving connection, and secondtol Patented Mar'. 9, 1926.

UNITED STATE-s 1,575,698 vPATENT OFFICE.

WILLIAM L. MCGRATH, OF ELMIRA, NE-W YORK, ASSIGNOR TO ECLIPSE MACHINE COMPANY, OF ELMIRA. NEW YORK, A CORPORATION O F NEW YORK.`

ENGINE STARTER.

Application led August 2, 1919. Serial No. 314,952:

vsuch as the liy Wheel of the engine to be started. The' object of my invention is to improve andmake practical that type ofK drive in which the automatic shifting move- 'ment of the driving membervor pinion into engagement With the engine member 1s accomplished by the employment of a pair of coacting spiral gears, one of-Which is a driving gear drivenby the starting motor either directly or indirectly, andthe other a driven gear mounted .for axial or longitudinal movement along the driving gear. The particular objects of my invention are first to provide this type of Vdrive with .a

provide the drive with means forl holding the driven'gear in normal position and to prevent re-meshing, which means is also capable of enforcing longitudinal lmovement of such driven gear when being automatical y moved axially or longitudinally.' .Other features of advantage and utility 1n my construction of drive will 'be apparent from the description hereinafter given.

In the drawing Fig. 1 is a sectional elevation of an engine starter embodyingmy in-V vention, thisparticular construction being of the out-board type; Fig. 2l a sectionalelevation on a modiied form of construction illustrating the in-board type; and F ig.v 3 a ldetail view of a modified form.

Referring to 'the particular embodlment of .myl invention as shown in Fig. 1 the electric starting` moto-r indicated at 1 is provided with lan iarmature shaft' 2 bearing in and extended beyond the end plate 3, attached to the motor frame in suitable manner as by bolts 4.' This plate 3 is provided with a laterally projecting-lnackct 5 'teiminating at its outer end in a bearing G and also. constitfuting a partial housing for the drive below.

Upon this extended armature shaft' 2-there is secured a spiral gear 7 which is therefore driven or rotated by the starting motor.

This gear meshes and coat-.ts with a complementary spiral gear S which is mounted loosely and adapted to slide. longitudinally upon a supporting shaft 9. This shaft'is supported at its inner end in the plate 3 and at its outer end in the bearing 6 to which latter it is secured in suitable manner as by .means of the pin 10. The gear 8 is provided with an outwardly extending hub 11 inwhich is mounted the means -for holding the gear .8 inv its normal position axially with respect to its supporting shaft. These means comprise in the present instance a plunger 12 reciprocating through a radial opening in the hub 11 and projected inwardly into the bore of such huband into a circumferential groove 13 in the shaft 9. This plunger is spring pressed by means of the coil spring 14C- bearing at its lower end against a collar lseeured to the .plunger and against a bracket 16 secured to and projecting from the outer face of the gear 8. The groove 13 and the plunger are so located that they coact at the time when the gear 8 is in its normal or home position illustrated in Fig. l. This plunger or spring pin isnot permitted to contact with the bottom of the groove but only With a side` thereof for reasons hereinafter explained. The driving member is'here in the form of a pinion 17 adapted to engage with the teetlrlS of the fiywheel 19 ofthe engine such as'an internal combustion engine. This pinion is loosely mounted on the shaft 9 so as to slide and also rotate thereon.. The shaft ismade of two diameters, the pinion being mounted on'the larger diameter. The pinion is vprovided with an inwardlyextending hub 20 and the two hubs 11 and 20 are operatively connected by a yielding driving connection 'which is here a coiled drive spring 21 Whose opposite ends are secured to said hubs by the anchorV studs 22 and 23 respectively. At. the shoulder24 formed at the junction between the two diameters of the shaft 9 I locate an antivfriction bearing 25 against which the hub result that the gear 8 will be automatically 110 moved along its shaft 9 to the right and the pinion 17 will be correspondingly moved longitudinally and into mesh with the flywheel gear.` then the electric` motor is thus started the acceleration is suoli as to jump the plunger or spring pin out of the groove 13 and permit said longitudinal movementof the parts. llhis longitudinal movement is assured by reason of t-he fact that the plunger l2 is in frictional contact with the surface of the shaft 9 whereby any tendency of the driven gear 8 to rotate is retarded.

-In such eases as might so require means may be provided kon the supporting shaft t) to further accentuate this effect such as the longitudinal corrugation QG as illustrated in Fig. 3.

After the pinion 17 is in mesh with the flywheel gear and its longitudinal move-ment is arrested by Contact of the hub .ll against the bearing 25, the gear 8 will rotate and such rotary motion will be communicated through the drive spring to" such pinion which latter will thereupon rotate the ilyivheel. lVhen the motor starts on its own power the assembly of pinion spring and spiral gear S are of course caused to rotate at a higher rate of speed than they are driven by the driving gear 7 and the demeshing will therefore automatically occur in the usual manner. By the provision of the plunger the gear 8 will be retained in its normal or home position and remeshing is prevented even though the armature and gears continue to rotate. that the plunger does not contact the bottom of the groove but only the side thereof, since contacting with the bottom would tend to resist rotation of the gear 8 and increase the tendency to longitudinal movement, whereas contact with the side of the groove prevents longitudinal movement of the gear on account of its state of rotation.

`In Fig. 2 I have shown a modified form of construction in which the corresponding parts are similarly numbered. In this con. struction the spiral gearing on the gears 7 and 8 run iu an opposite direction` .to that shown in Fig. l with the result that the assembly of driven gear spring and pinion will be automatically moved to the left along the supporting shaft when meshing with the Hywheel gear. This represents the iii-board type of drive inasmuch as the pinion moves inwardly towards the motor when meshing` with the flywheel gear.` In this construction the anti-friction bearing 25 is located at the inner end of the shaft 9 so as to be contacted by the .inner end of the inner side of the gear Fi when in operating position.

I In both forms of Construction, the drive spring permits ofthe relative longitudinal It will be noted movement of the pinion and driven gear which is desirable for meshing purposes.

I claim:

l. An engine starter drive Vcon'iprising a driving spiral gear, a second spiral gear driven thereby, an engine driving member adapted to be moved automatically into operative engagement with a member, of thev engine to be started andto thereupon drivey such engine member, a shaft on which lsaid driven gear and said driving member are loosely mounted, for both rotary and longitudinal movements, a driving connection between said driven gear and said driving member, and means initially tending to hold the pinion against longitudinal movement and thereafter to assure such movement and prevent rotary movement thereof on the shaft.

2. An engine starter drive comprising a driving spiral gear, a second spiral gear drven thereby, an engine driving member adapted to be moved automatically into operative engagement with a member of the engine to be started and to thereupon drivesuch engine member, a shaft on which said driven gear and said driving member are loosely mounted, for both rotary and longitudinal Infovements, a driving Connection between'said driven gear and said driving member, andineans initially tending to hold the pinion against longitudinal movement and thereafter to assure such movement and prevent rotary movement thereof on the shaft, such means consisting of a spring pressed plunger moutned on Athe driven gear and a groove in the shaft adjacent the normal position of the driven gear, the plunger normally being .positioned in the groove but adapted to` frictionally engage the shaft after the driven gear has moved longitudinally.

3. An engine Starter drive comprising a driving spiral gear, a second spiral gear driven thereby and having a hub, an engine driving member adapted tobe moved automatically into operative engagement with a member of the`engine to be started and to thereupon drive such engine 'member a shaft on which said driven gear and said driving member are loosely mounted for both rotary and longitudinal movements, said shaft being of two diameters with a dividing shoulder andv with the driving member on the larger diameter, an anti-.friction bearing at such shoulder against which bearing said gear hub abuts in the driving operation, and yielding driving connection between said driven gear and said driving member.

, WILLIAM L. MoGlL/Vlli.

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