US2321388A - Engine starter - Google Patents

Description

June 8, 1943. B. w. JONES ENGINE STARTER Filed Jan. 27, 1942 Patented June 8, 1943 i ENGINE STARTER Burr W. Jones, Elmira Heights, N. Y., assigner to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application January 27, 1942, Serial No. 428,350

' member I2 whichrmay be a portion of the housing 7 Claims.4

The present invention relates to engine starter gearing and more particularly to a detent for ensuring traversal of a starter pinion into mesh with a member of an engine to be started.

In those forms of starter drive involving a pinion arranged to be traversed into engagement with an engine gear by a threaded `connection with the starting motor, some form of detent is sometimes desirable for temporarily resisting rotation` of the. pinion to ensure its traversal. I Y It isranobject of the present invention to provide a novel detent for a starter pinion which is mechanically actuated as an incident to the operation of the starter switch.

Itis another object to provide such a device which is arranged to cause the detentto engage the pinion momentarily concurrently with closure ofthe starting switch. 'l

It is another objectto'provide such a device in which the detent is retracte'dfrom the pinion 'as a consequence of nal movement of the'switchclosing means. Y ','It is another object to provide such a device in.l which the detent is thereafter held retracted until after release and re-actuation of the starting switch. y "Further objects and advantageswill be lapparent from the following description taken in connection vwith the *accompanying drawing, -in Wmch't-- Fig. l is a semi-diagrammatic illustration cfa starting system embodying the present invention, showing the starting switch and detent. actuating means in side elevation partlybroken awayand in section; lr v Fig.2 is a similar view of the switch and detent mechanism showing theparts in thepositions assumed when the starting switch is closed and the detent ready to trip; Y

Fig. 3 is a similar view showing the positions 5 of the parts during the cranking operation of the engine, and

Fig. 4 is a detail of the detent and pinion in end elevation.

In Fig. 1 of the drawing there is illustrated a starting circuit including a battery I grounded at 2 and connected by a lead 3 to a starting switch indicated generally by numeral 4. The switch is connected by a lead 5 to a starting motorSM which is grounded at 6 to complete the starting circuit. Switch 4 comprises a casing 1 in which stationary insulated contacts 8 and 9 are xed in any suitable manner, and which casing is mounted of the starting motor.

A houow plunger ls is sndabiy mounted inthe sleeve I I and has pivoted thereon at its lower end,

as indicated at I4', a curved detentmembe'r I5 which extends withinthe housing I2 adjacent a starting pinion I6, threaded on a screw shaft I1 adapted to be rotated by the starting motor SM. The detent I5 is formed .as shown`- in Fig. 4 so as to be engageable between the teeth of the pinion I5 to resist rotation thereof and hence assure its traversal into operative position upon initialrotation of the screw shaft'I'I. f

Plunger I3 is normally maintained in retracted position as illustrated in Fig. 1 by means of a spring I8, and means are .provided for manually as by means of a threaded sleeve I I on a housing projecting the plunger to cause engagement of the detent I5 with the pinion I6, in the form of a push rod I9 coupled to the plunger I3 as indicated at 2l and having a push button 'or knob 2 2 fixed thereon at its upper fend asfshownjat' 23 and eX- tending outside thecasingfl for convenient manipulation by the operator.- j I A switch member 24 is slidably mounted on the push rod I9 in position to engage and connect the contacts and 9 of the starting switch when the push rod is depressed,[ Asuch engagement being maintained while ,permitting further travel of the, push rod by'virtue pf anspring 25 bearing on the contact 2,4 and against a shoulder 25 on the knob22. 'K L According tothe present invention means are provided for causing the detent' I5 to be retracted kfrom thev pinion I6 as `a consequence to nal downward movement of the plunger I3 after Closure of the starting switch, and for thereafter Vmaintaining ,the detent retracted until after release and re-actuation of the starting switch.

YA s Vhere shown this,A isaccomplishedv by forming'fa flattened Surfa e 2l Onthe upperend 0f the detent I5, and providing a thrust block 28 slidably mounted within the hollow plunger I3 and pressed into engagement with the upper end of the detent by means of a spring 28. The attened surface 21 is so located, as shown, that when the detent is in idle position the block 28 bears on the round portion of the detent and frictionally resists pivotal movement of the detent around its mounting pin I4. After initial pivotal movement has taken place, however, as illustrated in Fig. 2, the block 28 cooperates with the flattened surface 2l to cause further rotation of the detent and consequent withdrawal of the detent from the pinion.

In operation, starting with the parts in position as illustrated in Fig. 1, depression of the knob 22 by the operator causes the detent I5 to be moved into engagement with the pinion I6 and then causes contact 24 of the starting switch to engage the xed contacts 8 and 9 thus completing the starting circuit. The consequent rotation of the starting motor while the detent resists rotation of the pinion causes the pinion to be traversed into operative position. The further depression ofA the knob 22 by the operator causes the detent I to bottom on the root diam;

eter of the pinion, and since its translatory movement is then obstructed, it is caused to turn on the pivot I4 into the position shown in Fig. 2. The plunger 28 then cooperates with the flat sur-` face 21 of the detent to move the detent out of engagement with the pinion as shown in Fig. 3 where it is held during the cranking operation.

When the engine starts, release of the knob 22 by the operator permits the springs I8 and25 to return the parts to their idle'pfo'sitions.Y Since the upper end of the detent I5 isshape'd tofconform with the opening in the lower end of the sleeve II, the final return movement of the plunger I3 causes the detent tobe rotated by its engagement with *said sleeve into its normal position as shown in Fig. 1.

Rotation of the plunger and detent aboutV the axis of 'the plunger is preferably prevented by any `suitable means such as a pin 30 slidably mounted in a slot 3| in sleeve II so Vas to spline the plunger within said sleeve.

It will be noted by reference to Fig. 4 of the drawing that the contour of the detent is such that the teeth of the pinion will exert acamming force thereon when the pinion isvpositively rotated by the starting motor during the cranking operation. If thedepression Vof the knob 22 by the operator is so slow that the pinion reaches its operative position before the plunger I3 is completely depressed, the pinion will therefore simply cam the detent out from 1 between its teeth, and retraction of the detent by the block 28 will'then take place in the usual manner. v Although but one embodiment of the invention has been described and shown in detail, it will be understood that other embodimentsY aepo'ssible and that various changes may be Amad'efin the 'design and arrangement of the parts `without departing from thev spirit of the invention as defined in the claims appended hereto.

What is claimed is: y Y

1.. In an engine starter a starting circuit including a motor and a starting switch, a screw shaft driven by the starting motor, a "pinion having a `threaded connection with the Vscrew shaft, a detent for the lpinion, and means 'for closing the starting switch and concurrently moving the detent into engagmentwith the pinion, said means including means v vher'eby movea pinion, means actuating the pinion from the .motor to engage and drive a member of an engine to be started, actuating means for the ment thereof beyond the switch-closing position causes retraction of the detent from the pinion,

2. A starting system as set forth in claim 1 in which the retracting means for the detent holds said detent out of engagement with the pinion during the cranking operation and during the opening of the starting switch. v

3; A starting system as set forth in claim 1 in which the detent is of such a contour that the teeth of the pinion will engage and cam the detent away from the pinion when the pinion is positively rotated by the motor.

4. In an engine starting system a starting circuit including a. fmotor and a starting switch,

switch, means movably carried by the actuating means for momentarily engaging the pinion to resist rotation -the-reofy'lan'd means responsive to relative' movement betvvenltne .actuating means.

and 'the pinion-'engaging means "for retractng the pinion-engaginglmeans.

5. In an engine'st ,a'r'tingv system a 'startingcircuit including a 'motor 'and a starting Asivitchya. pinion having a threaded 'Connection With'thmotor and movable thereby to .engage-and drive a member of an engine to 'be started,` actuating means for the switch, af detent carried by the switch-actuating means' and yn'ovable thereon into` and Yout of Operativep'sitioh; -iens responsive to iinal closing movement of thesis/itchiactuating means 4for mvin'gthe deterti'tf operative position, and means responsive ftonal opening movement of theswitcheactuating mafrlsY ior returning the detent to joperative@position on saidactuating means. p j Y 6. As an articleof manufacturega swithn'and pinion Vdetentunit forengine startersvincluding a casing having 'switch contacts fixed therein; a plunger movably mounted in the'casingfa contact carried by the plunger 'and movable therewith to engage the Xe 'contact'sfa tet mounted on the plunger 'for pivotal movement into and out ofl operative position,` said detent having an arcuate suriace'and -a flat surface, and yielding means jengaging the arcuate Vsurface'ei the detent for frictionally holding the detentrn operative position and arranged -to cooperate with the flat surface Lof the detent-torotate the detent jto inoperative position when its movemen withtheplun'geris obstructed. 7. A switch and detent unit as set forthin' claim 6 including yfi'irther, means `for `returning the detent to operativelpositon'With-respt 360' the plunger vresponsive to switch-opening rx'i'v'c'ement of the plunger.

' Brian w. .iones

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