US2778228A

US2778228A - Engine starter drive

Info

Publication number: US2778228A
Application number: US447343A
Authority: US
Inventors: Paul L Schneider; William H Taylor
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1954-08-02
Filing date: 1954-08-02
Publication date: 1957-01-22
Anticipated expiration: 1974-01-22

Description

Jan. 22, 1957 P. l.. scHNElbER ET AL 2,778,228

ENGINE STARTER DRIVE l Filed Aug. 2, 1954 2 Sheets-Sheet 1 @ZM 1%@ ATTORNEY Jan. 22, 1957 P. l.. SCHNEIDER ET AL 2,778,228

ENGINE STARTER DRIVE 2 Sheets-Shee' 2 Filed Aug. 2, 1 954 INVENToRs PAUL L. 5c///\/E/DE/Ql By WILLIAM/v. 72H/012 m ATTORNEY United States Patent O ENGINE STARTER DRIVE Paul L. Schneider and William H. Taylor, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 2, 1954, Serial No. 447,343 7 Claims. (Cl. 74-7) This invention relates to engine starter drives of the type wherein rotation of the starting motor shaft effects the meshing of the motor driven pinion with the engine ywheel gear and in which the pinion is automatically demeshed from the flywheel gear when the engine becomes self operative.

In starting devices of this character the pinion is sometimes demeshed when it is not desirable as in the case of a false start, when the engine makes a few turns but does not continue to run. In such event the engine can not be restarted until the starting motor has come to rest, which is, of course, objectionable.

The primary object of the present invention is to provide novel and improved means for preventing demeshing of the pinion in case of a false start and to hold the pinion in gear engaging position until the engine is fully self operative, so as to prevent the necessity of opening the starter switch and waiting for the starting motor to come to rest before repeating the starting operation.

Further objects and advantages of the present invention will be `apparent from the folowing description, reference being had to the accompanying drawings, wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

Fig. l is a side elevation partly in vertical section of a starting motor and associated drive embodying the present invention.

Fig. 2 is a vertical section on the line 2-2 of Fig. l.

Fig. 3 is a vertical section on the line 3-3 of Fig. 1.

Fig. 4 is a fragmentary plan View partly in section of a detail of construction.

Fig. 5 is a detail plan view of a part of sleeve 18.

Figs. 6 and 7 are views similar to Figs. 3 and 4, respectively, of a modied form of the invention.

The starting motor and drive is of much the same type as shown in the patent to Schneider Re. 23,359, April 17, 1951, and this -device may be termed an improvement on that shown in such patent. Referring to the drawings and particularly Fig. l, a housing 2 supports a motor field frame 4 and the housing is either integral with or connected to an extension 6 in the end of which one end of the motor shaft 8 is rotatably supported, the other end of the shaft being supported in the end frame 10 which is secured to the right end of frame 4. The motor shaft 8 rotates a llywheel 12 through the medium of pinion which is automatically moved into engagement with the ywheel gear and connected in driving relation With the motor shaft by a starter drive device which will now be described and which is designated in general by the numeral 16.

A sleeve 18 is supported on the motor shaft and is secured thereto by a pin 20 which extends through holes in the sleeve and an enlarged part 22 of the sleeve. Surrounding the part 22 is a ring 24 through which the pin 20 also extends and a retaining wire 26 positioned in a groove in the ring holds the pin in place. the left from the ring 24 is a stop lug 28 integral with` the Extending to j 2,778,228 Patented Jan. 22, 1957 ring and this lug cooperates with a corresponding lug (not shown) which extends to the right from a sleeve 30, which is supported on the -sleeve 18, to determine thev normal, initial position of the parts. The stop lug which extends from the sleeve 30 is normally held against the lug 28 by a torsion spring 32 which surrounds the sleeve 18 and which has one end connected in any suitable way with the ring 24 and the other with sleeve 30. This spring will rotate the sleeve 30 so that normally the partsy are in the position shown and the stop lugs are in engage-v ment with each other.

The sleeve 30 has internal threads 34 which engage external threads 36 on the sleeve 18 so that relative rotary motion between the two sleeves in one directionv will cause the sleeve 30 to move axially toward the left to engage the pinion with the flywheel gear and in the: other direction will cause the sleeve 30 to move to the right to effect disengagement of the pinion and gear.

Positioned immediately to the left of the sleeve 30 is` another sleeve 40, the right end of which is normally in engagement with the left end of sleeve 30, which 'has a reduced end 42 extending into the sleeve 40, the internal a ring 46 which ts around the left end of the sleeve i0v and has inwardly projecting splines 48 which extend into the spaces between the teeth of the pinion 14. The pinion is slidable and rotatable on the shaft 8 and has a sleeve 5d extending to the right, the outer diameter of which is substantially the same as the inner diameter of a flange 52 which projects inwardly from the inner wall of sleeve 4t) and which surrounds the sleeve 50. Extending fromy the pinion teeth to this ange and lying between the inside of sleeve 40 and outer surface of sleeve 56 is a space 53 in which is positioned a compression spring S4 which tends to move the pinion to the left relative to the sleeve 40 but this movement is limited by a stop wire 56 received in a groove adjacent the end of sleeve 50.

The spring 54 normally retains the parts in the position shown in Fig. l but if, when the pinion is moved to the left to engage the flywheel, the teeth abut those of the flywheel the spring 54 will yield, the sleeve 4d will continue to move toward thev left until rotary movement of the pinion takes place. As such movement begins the teeth are brought into proper alignment and the spring will snap the pinion into proper meshing position as soon` as this takes place.

When axial movement of sleeve 30 on sleeve 13 stops, as the pinion is moved to its gear engaging position the sleeve 30 will rotate with sleeve 18, but in order to rotate the pinion rotary movement of sleeve 40, which drives the pinion through the medium of splines 48, must be etected. With the parts in the position shown in Fig. l rotation of sleeve 30 does not effect rotation of sleeve '10 and a clutch is providedy to eiect driving engagement between

sleeves

30 and 40 after the pinion has moved into proper driving relation with the flywheel gear and its axial movement to the left has stopped.

The pinion is moved to the left, to the dotted line posi-- tion of Fig. l where its axial movement is stopped by a` stop washer 60 tted on the shaft 8 adjacent a stop washer 62 positionedin a groove 64. The washer 62 is really two half washers held together by a clamping washer 66 in the manner described in the aforementioned patent to Schneider, the construction being the same as that of the patent. After the pinion reaches this position, or in the event of tooth abutment, the clutch becomes effective to couple the sleeve 30 to sleeve 40 to effect rotation of the pinion.

This driving clutch includes a torque transmitting springl 70 whichsurrounds theouter surfaces of sleeves 30 and-40 with one end of theA spring engaging the right end of the ring 46, as seen in Fig. 1, and the other end of such spring engaging a shoulder at the left end` of an outwardly extending flange 72., which is integral with the sleeve 30 and ,is formed at thelrightenddof the smaller diametered portion 31` of such sleeve. The spring is retained endwise by a cylindrical cover 74 which has an inwardly extending flange 76 at one end engagingthe ring 46 ,andA a similarflange 78 at the opposite `end engaging in a groove 80 formed in the outer surface ofthe ilange 72. Afterthepinion has reached its properengaging .position or in the event that its movement to the left is stopped by tooth abutment the sleeve 30 will rotate and cause the turns of the spring to grip the outer Surface of sleeve 40 and the reduced part `31` of sleeve 30, so that rotation of sleeve 40 and the pinion is effected, producing rotation of gear 12`to start the engine.

The mechanism so far described is substantially the sameas that disclosed yin the above mentioned Schneider patent.

When the engine isstarted and becomes self operative,

as the result o f rotation of gear 12 by pinion 14, it tends to drive` the pinion faster than it can be driven by the starting motor and the pinion is automatically disengaged from they gear 12 due to the threaded connection between the sleeves 13 and 30, the action being substantially the reverse of that which takes place when the pinion is moved into driving engagement with the gear 12. This action is aided by spring 32 which has been additionally stressed when, the pinion is engaged,

As already stated, if an engine does not remain self operative after it first res but makes a false start, the pinion will sometimes be disengaged from gear 12 before the engine stopsvand if this occurs it is necessary to wait until the starting motor stops running before the engine can be restarted, which is objectionable. In order to eliminate this diiiiculty devices have been provided. which are designed to prevent disengagement of the pinion from theengine gear in the event of a false start and to maintain the pinion in engaged position until the engine becomes fully self operative. Such a device is shown in the above mentioned patent to Schneider. This is the detent plunger 90 carried by the sleeve comparable to sleeve 30 and which, when the pinion is advancedto gear engaging position, drops into a sort of notch or flattened surface formed on the threadedpart of sleeve which corresponds to applicants sleeve 18. The detent is held in this position by a spring which is supposed to be overcomepby centrifugal force after the engine becomes self` operative. This willreflect release of the pinion and it will be moved back to its normal position as previously described. However, it has been found that sometimes the centrifugal force becomes sufficient to release the detent on a false start, and the device disclosed herein is designed to prevent any release of the pinion until the.

engine is fully self operative `and to make it impossible to effect release of the pinion in the event of a false start.

According to the present invention a spring held detent similar to that of the aforementioned patent is employed and it cooperates with a notch or iiattened surface on the threaded part of the sleeve 18, but the action of the detent is entirely different, being positively held in engagement with said notch until the starter switch is opened.

The detent is designated 90 and is slidable in a cylindrical opening in sleeve 30 normal to the axis thereof as indicated in Fig. 1. The detent is urged toward the periphery of sleeve 18 by a spring 92 which is received in a Cylindrical rcess in, the .detent plunger and has one ,ends engagingthe bottomI of the recess AWhile the 4, other engages a ring assembly, designated in its entirety as 96, which surrounds the sleeve 30 and the detent, having a notch 98 into which the detent extends.

In order to latch the pinion in its gear engaging position spring 92 moves the detent into a notch 99 formed on the surface of sleeve 18 as shown in Fig. 2.

The ring assembly 96vcomprises three annular rings or

Washers

100, 102 andliwhich have a tight lit on the peripheral surface of the sleeve 30 and the notch 98 is formed in all of these rings. A fourth ring 106 .is positioued adjacent the ring 104 and this ring has aviiange 10S extending therefrom, which surrounds the

rings

100, 102 and 104, as indicated in Fig. l, while tangs 110, bent inwardly from this ange hold the ring assembly together, but not tightly enough to prevent relative movement of rotation between the ring 106 and the other three rings of the assembly. It is also desirable that the flange 108 lits loosely enough on the outer circumference of the

rings

100, 102 and 104 which it surrounds to permit the ring 106 to move readily with respect to the other three rings and for the same reason the inner diameter of the ring 106 should be such that the ring is freely movable on sleeve 30.

The ring 106 has a notch 112 into which the detent 90" extendsas indicated in Fig. 3 and at one side of this notch the side wall is cut away adjacent the inner circumference of the ring to form a latching shoulder 114,' as shown in Fig. 3. This shoulder is designed to hold the detent in its latching position as Ilong as the circuit of the starting motor remains closed, so as to preventrelease of the detent upon false starts and to this end `the disengagement of the shoulder 114 from the detent is controlled by the operation of the starting motor switch ina manner which will be more fully described later. It should be particularly noted that with the parts in the position shown in Figs. l and 3 the shoulder can not'I engage the end of the detent as the latter is further from the axis of the motor shaft than the shoulder, but when the detent drops into the notch 99, as in Fig. 2, the outer end of the detent moves toward the motor shaft far enough for the shoulder 114 to move over the end of the detent to hold it in the Fig. 2 position, until released by opening of the control switch for the starting motor.

The engagement and disengagement of shoulder 114 with the end of detent is effected in the following manner. The ring 106 not only has the notch 114 yformed therein, but also has a notch 116 into which a pin 11S extends, the

notches

114 and 116 being considerably wider than the detent 90 and -pin 118, respectively, so that ring106 can have considerable rotary movement relative to both the detent and pin. The pin 118 extends through the notch `116 and through openings inthe three

rings

100, 102 and 104, in which it is secured in any suit-f able way. One end of a torsion spring 120 is looped around a groove 122 in the pin. This spring extends entirely around the sleeve 30 and the other end ofthe spring is bent in a direction normal to the exis of the motor shaft, as indicated at 124, and such end of the spring extends through a hole in a laterally oiset tang 126 extending to the right of ring 106 as viewed inrFig.

l. The spring normally tends to move the ring 106 in the direction ofthe arrow -in Fig. 3 and whenever the detent 90l is moved to the Fig. 2 position, which occurs when the pinion is fully meshed with the ywheel gear, the ring will be so moved and the shoulder 114 will engage-the outer end of the detent as previously described. The ring 106 will remain in this position until lthe starting motor switch is opened and the opening of this switch will effect reverse movement of the ring 106 and release of the detent.

As shown herein the starter switch is a magnetic switch which ispositioned in a housing 130 having a projectingange 132 which is secured by screws, or in any suitable way, to a flattened mounting surface 134 formed on the upper sideof the housing 2 and surrounding an opening,

136. The switch comprises two

xed contacts

138 and 140 supported by the wall of the housing 130 and suitably insulated therefrom. These contacts are connected with

binding posts

142 and 144 respectively to which conducting cables leading to the conventional storage battery are adapted to be connected. These contacts are adapted to be engaged by a movable contact 146 carried by and suitably insulated from the armature 148 of an electromagnet having a winding 150 the energization of which is effected by a manually operable control switch, not shown. A spring 152 normally holds the switch open, this spring being overcome by the force of the magnet when energized and moving the parts to the position shown in Fig. l as soon as the magnet is deenergized. The specific construction of the starter switch forms no part of the present invention so it is deemed unnecessary to describe it in greater detail herein and the control of the magnet may be entirely conventional as by a separate plunger or by the ignition.

The armature 148 of the switch operating magnet has an extension 154 which slides in an opening in the plate 156 positioned adjacent the lower end of the housing 130 and at the bottom of this extension is an enlarged head 158 the lower surface of which is liat and which will engage the peripheral surface of flange 108 when the switch is open and the armature in the Fig. 1 position to act as a brake and retard rotary movement of ring 106. This head may be metal or its surface may be of some suitable non-metallic brake material.

As already stated, when the shoulder 114 is in engagement with the outer end of the detent the pinion is latched in its proper gear engaging position and it will remain so locked until the above described starter switch is opened. When this takes place the armature will move downwardly, the head 158 will engage the flange 108, which is moved axially to a position in alignment with the armature when the pinion is moved to gear engaging position. This will oppose the movement of ring 106, so that the balance of the ring assembly 96 and the detent 90 will move in the direction of the arrow in Fig. 3, relatively to ring 106, moving the detent out of engagement with the shoulder 114 and centrifugal force will then release the detent from notch 99 in sleeve 18, thus permitting disengagement of the pinion from the engine gear.

The starter switch can be maintained in closed position by the operator until the engine has become fully and permanently self operative and disengagement of the pinion from the engine gear will be positively prevented until this occurs.

In Figs. 6 and 7 a device is shown which is a modified form of the device previously described and which, instead of employing a positive latch for the detent such as the shoulder 114, utilizes a spring in addition to spring 92 of suflcient strength to prevent any possible movement of the detent in response to centrifugal force until the pinion reaches a speed that would never be attained in a false start and which spring is engaged with and disengaged from die end of the detent in the same way as the shoulder 114.

As shown in Figs. 6 and 7 the structure is just the same as that which has previously been described except the shoulder 114 is omitted and, instead, the ring 106 has a cutout tang 160 extending laterally therefrom and to the right, as seen in Fig. 1. Secured on top of this tang by welding or in any other suitable way is a flat spring 162 which extends substantially parallel to the ring assembly 96 from the tang to a point adjacent notch 112 where a toe 164, which lies at substantially 90 to the main part of the spring, projects into the notch 112 and alongside the detent 90, the notch 98 in the

several rings

100, 102 and 104, being widened in the modified form of the device su'iciently'to receive the toe as shown in Fig. 7. This spring, like shoulder 114, can not engage the outer end of the detent unless it is in its Fig. 2 position but as soon as` the detent assumes such position the ring 106 is moved so that the toe 164 engages the detent and it is not moved out of engagement therewith until the brake member acts on the flange 108 as previously described.

The only difference in function between this form of the device and that previously described is that in the modified form the detent is not positively latched, but the spring 162 exerts so great a force that the detent could not be lreleased until the spring is disengaged therefrom unless a speed of approximately 4000 or more R. P. M. is attained, at which the centrifugal force might be effective to overcome the force of the spring. This, however, is a speed greater than is ever attained during a false start, and it will be understood that in any installation a spring is used which is of sulicient strength to prevent release at any speed which could possibly be reached before the engine becomes fully and permanently self operative.

While the forms of embodiment of the invention as herein disclosed constitute preferred forms, it is to be understood that vother forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

l. Engine starting apparatus comprising an electric starting motor, a pinion rotatable thereby to crank the engine, means for moving the pinion into and out of engagement with a gear of the engine to be started and for operatively coupling the motor and pinion to cause the pinion to be rotated by said motor, said last named means including a helically splined sleeve rotatable with the motor shaft and having a notch formed therein, a second sleeve which is rotatable on the rst sleeve to move the pinion into engagement with the engine gear but rotatable therewith after the pinion is in engaging position to effect rotation of the engine gear, a spring biased detent carried by the second sleeve movable into engagement with said notch when the pinion is fully engaged with the engine gear to hold the pinion in gear engaging position, a latch member rotatively movable into engagement with the detent when the latter engages the notch to hold the detent in such position, and means for moving the latch out of engagement with the detent when the starting motor is deenergized.

2. Engine starting apparatus comprising an electric starting motor, a pinion rotatable thereby to crank the engine, means for moving the pinion into and out of engagement with a Ivgear of the engine to be started and for operatively coupling the motor Iand pinion to cause the pinion to be rotated by said motor, said last named means including a helioally splined sleeve rotatable with the motor shaft and having a notch formed therein, a second sleeve which is rotatable on the first sleeve to move the pinion into engagement with the engine gear but rotatable therewith after the pin-ion is in engaging positionv .to effect rotation of the engine gear, a spring biased detent carried by the second sleeve and radially movable in said sleeve into engagement with said notch when the pinion is fully engaged with the engine gear to hold the pinion in gear engaging position, a latch member movable into engagement with the detent when the latter engages the notch to hold the detent in such position, a

switch for controlling operation of the starting motor hav-ing a contact movable to different positions to open and close the starting motor circuit, a movable member `supporting said contact and movable -to a position to elfect disengagement tof said latch member from the detent when said m-ovable member is moved to position to open the control switch.

3. Engine starting apparatus comprising an electric starting motor, ya pinion rotatable thereby to crank the engine, means for moving the pinion into and out of engagement with 'a gear of the engine to be started and for operatively coupling the motor and pinion to cause the pinion to'b-e rotated by said motor, said last named means including a helically splined'sleeve rotatable with the'fmotor shaft land having a notch formed therein, a Second sleeve which is rota-table on the rst sleeve to move the pinion into engagement with the engine gear but rotatable therewith after the pinion is in enga-ging position to effect rotation of the engine gear, a spring biased detent carried by the second sleeve `movable into engagement with said notch when the pinionY is fully engaged with 'the engine gear to hold the pinion in gear engaging position, a latch supporting member carried by the second sleeve, rotatable therewith and also rotatable thereon, means for rotating said latch member rela tive to said sleeve and detent and into engagement with the detentwhen the latter engages the notch so as to hold the detent in such position, and means movable into engagement with the latch supporting member when the starting motor is deenerg-ized to oppose rotation of the -latch member in order .to disengagev the latch member from said detent when the engine becomes se'lf'opera tive.

4. Engine star-ting apparatus comprising an electric starting motor, a pinion rotatable thereby to crank the engine, means for moving the pinion into and out of engagement with a gear of the engine to be started and for operatively coupling the motor and pinion to cause the pinion to be rotated by said motor, said last named means including 'l helically splined sleeve rotatable with the motor shaft `and having a notch formed therein, a second sleeve which -is rotatable on the first sleeve to move the pinion into engagement with the engine gear but rotatable therewith after the pinion is in engaging position to eiect rotation of the engine gear, a spring biased detent carried by the second sleeve movable into engagement with said notch when the pinion is fully engaged with the engine gear vto hold the pinion in gear engaging position, a latch supporting member carried by the second sleeve, rotatable therewith and also rotatable thereon, means for rotating saidlatc-h member relative to said sleeve and detent and into engagement with the detent when the latter engages the notch so as to hold the detent in such position, a switch for controlling operation of the starting motor having a con-tact movable to different positions to open and close the starting motor circuit, ya movable member supporting said contact and movable to a position to engage -the latch member and 'oppose lrotation thereof when moved to open the control switch in order to eiect disengagement of .the latch member from the notch when the starting motor is deeuergized.

5. Engine starting apparatus comprising an electric starting motor, a pinion rotatable thereby :to crank the engine, means for moving the pinion into and out of engagement with 'a gear of the lengine to be started and for operatively coupling Ithe motor and pinion to cause the pinion to be rotated by said motor, said last named means including a helically splined sleeve rotatable with .the motor shaft and having a notch formed therein, a second sleeve which is rotatable on the first sleeve to move the pinion into engagement with the enginegear but rotatable therewith after the pinion is in engaging position to eifect rotation of the engine gear, a spring biased detent carried by the second sleeve movable into engagement with said notch when the pinion is fully engaged with the engine gear to hold the pinion in gear engaging position, a latch supporting member carried by the second sleeve, `rotatable therewith and .also `rotatable thereon, means for rotating said latch member relative to said sleeve and detent and into engagement with the detent when the latter engages the notch so 'as to hold the detent in such position, said latch member being resilient and effective to hold the detent in engagement with the notch until the engine is operating `at ya predetermined speed, and means movable into engagement with the latch supporting member when the starting motor is deenergized to oppose rotation of the latch member and effect disengagement lthereof from said detent so as .to permit disengagement of the detent from the notch when the engine is operating at a speed less than saidpredetermined speed.

6. Engine starting apparatus comprising an electric starting motor, a pinion rotatable thereby to crank the engine, means for moving the pinion into and out of engagement with a gear of the engine to be started and for operatively coupling the motor and pinion to cause the pinion to be rotated by said motor, said last named means including a helically splined sleeve rotatable with the motor shaft and having a notch formed therein, a second sleeve which is rotatable on the first sleeve to move the pinion into engagement with the engine gear but rotatable therewth after the pinion is in engaginsY position to effect rotation of the engine gear, a spring biased detent movable in response to centrifugal force and carried by the second sleeve movable into engagement with said notch when the pinion is fully engaged with the engine gear to hold the pinion in gear engaging position, a latch supporting member carried by the second sleeve, rotatable therewith and also rotatable thereon, means for rotating said latch member relative to said sleeve and into engagement with the detent when the latter engages the notch so as to hold the detent in such position against said centrifugal force, said latch member being resilient and effective to hold the detent in engagement with the notch until theV engine is operating at a predetermined speed, means movable into engagement with the latch supporting member when the starting motor is deenergized to oppose rotation of the latch member and effect disengagement thereof from said detent so as to permit disengagement of the detent from the notch when the engine is operating at a speed less than said predetermined. speed, a switch for controlling operation of the starting motor having Xed and movable contacts, and a member supported on the movable contact and movable into engagement with the latch supporting member when the switch is opened to efect disengagement of the latch member from the detent when the starting motor is deenergized.

7. Engine starting apparatus comprising an electric starting motor, a pinion rotatable thereby to crank the engine, means for moving the pinion into and out of engagement with a gear of the engine to be started and for operatively coupling the motor and pinion to cause the pinion to be rotated by said motor, said last named means including a helically splined sleeve rotatable with the motor shaft and having a notch formed therein, a second sleeve which is rotatable on the rst sleeve to move the pinion into engagement with the engine gear but rotatable therewith after the pinion is in engaging position to effect rotation of the engine gear, a spring biased detent movable in response to centrifugal force carried by the second sleeve movable into engagement with said notch when the pinion is fully engaged with the engine gear to hold the pinion in gear engaging position, a latch supporting member carried by the second sleeve, rotatable therewith and also rotatable thereon, means for rotating said latch member relative to said sleeve and into engagement with the detent when the latter engages the notch so as to hold the detent in such position against said centrifugal force, said latch member being resilient and effective to hold the detent in engagement with the notch until the engine is operating at a predetermined speed, means movable into engagement with the latch supporting member when the starting motor is deenergized to oppose rotation of the latch member and effect disengagement thereof from said detent so as to permit disengagement of the detent from the notch when the engine is operating at a speed less than said predetermined speed, a switch for controlling operation of the starting motor having fixed and movable contacts and including a rod connected at one end to said movable contact, said rod being movable in a di- 9 10 rection normal to the axis of the motor shaft and effective References Cited in the Ele of this patent when moved toward said shaft to open the starter switch, UNITED STATES PATENTS the opposite end of said rod being brought into engagement with the latch supporting member by such move- 2394690 Hod Feb' 12 1946 ment to oppose rotation of the last named member and 5 2'397033 Miller Mar' 19 1946 disengage the latch when the starting motor is deener- 2441772 Mluer May 18 1948 gized.