US1883388A

US1883388A - Engine starter

Info

Publication number: US1883388A
Application number: US495901A
Authority: US
Inventors: William L Mcgrath; Maurice P Whitney
Original assignee: Eclipse Machine Co
Current assignee: Eclipse Machine Co
Priority date: 1930-11-15
Filing date: 1930-11-15
Publication date: 1932-10-18
Anticipated expiration: 1949-10-18
Also published as: DE589359C; FR726217A; GB388489A

Description

ENGINE STARTER Filed Nov. 15; 1950 IIIIIIII/I l/VVENTOR William L. McGrath- 11y Maurice P Whiine M J. /z TTOIRNEV Patented Oct. 18, 1932 UNITED STATES PATENT OFFICE WILLIAM L. MCGRATH AND MAURICE P. WHITNEY, OF ELMIRA, NEW YORK, ASSIGNOBS 'I'O ECLIPSE MACHINE COMPANY, OF ELMIRA, NEW YORK, A CORPORATION OF NEW YORK ENGINE STARTER Application filed November 15, 1980. Serial No. 495,901.

This invention relates to engine starters and more particularly to a drive or transmission adapted to automatically connect and disconnect a starting motor from an element, such as the flywheel, of an internal combustion engine to be started.

The invention as herein disclosed is embodied in a drive of the screw-shift type in which a pinion is adapted to be driven by astarting motor, the pinion being automatically traversed into mesh with a flywheel gear by acceleration of the starting motor, and out of mesh therewith when the engine starts.

One object of the present invention is to provide a novel automatic shift which is efficient and powerful but of small overall dimensions.

Another object of the invention is to provide such a drive including a novel and efficient arrangement of yielding elements for insuring meshing and the transmission of cranking torque.

Another object is to provide such a drive including new and improved anti-drift means and positioning means for yieldably maintaining the pinion and the pinion actuating member in their normal positions relative to the engine member.

Further objects and advantages will become apparent to those skilled in this art from the following description taken in connection with the accompanying drawing in which;

Fig. 1 isa side elevation, partly in section, of a preferred form of the present in- I vention;

Fig. 2 is an end view of certain of the parts thereof;

Fig. 3 is a View similar to Fig. 1, showing the parts in cranking position;

Fig. 4 is a view simllar to Fig. 1 showing the positions which the parts would assume if the teeth of the pinion should engage end to end is against the teeth of the engine flywheel;

Fig. 5 is a side elevation partly in section of an actuating member for the pinion; and

Fig. 6 is an end view of the same.

Referring first to Fig. 1 of the drawing, a

An actuating member in the form of a threaded sleeve 17 is provided with splines 18 (Figs. 5 and 6) adapted to engage the splined portion 13 of the shaft, and is counter-bored as indicated at 19 to allow the actuating memher to slide freely over a. considerable part of the smooth portion 11 of the driving shaft as well as the splined portion 13 thereof.

Positioning means for the actuating member in the form of. a heavy compression spring 20 and a light compression spring 21 are mounted on the smooth portion 11 of shaft 10, the heavy spring 20 being adapted to bear against a thrust ring 22 which is seated against the shoulder 12 of shaft 10, and the light spring 21 being adapted to bear against a thrust washer 23 which in turn bears against the end of the actuating member 17. Springs 20 and 21 are both somewhat shorter than the distance between the

thrust members

22 and 23 and spring 21 is arranged to telescope within spring 20. A connecting member in the form of a thimble 24 is arranged between the telescoping portions of

springs

20 and 21, and is provided with an inwardly extending flange 25 adapted to receive the inner end of spring 21, and an outwardly extending flange 26 adapted to form a seat for the free end of spring 20, whereby the two springs are in effect connected end to end.

Thrust member 23 extends radially beyond the spring 21 and is adapted to bear against the end flange 26 of thimble 24 after a predetermined compression of spring 21 so that further motion of thrust member 23 in a direction to compress the springs is resisted directly by the heavy spring without causing further compression of spring 21. The space between flange 25 of thimble 24.- and the thrust ring 22 is arranged to allow for the maximum compression of spring 20.

A stop member in the form of a sleeve 27 is adapted to be mounted on the outer part of the splined portion 13 of shaft 10. Said stop member has an out-turned shoulder 28 at one end adapted to contact and form a stop for the end of actuating member 17, and an inturned flange 29 at its other end adapted to bear on the smooth portion 15 of shaft 10 and seat against the shoulder 14 formed by the end of splined portion 13.

An anti-drift thrust member in the form of an annular Washer 30 is slidably mounted on the stop sleeve 27 and is yieldably maintained against the shoulder 28 of said sleeve by means such asa light compression spring 31. Spring 31 is retained on the sleeve 27 by an abutment member in the form of an annulus 32 seated on the smooth portion 15 of shaft 10, bearing against the flange 29 of sleeve 27 and extending over said sleeve to form an annular recess 33 which is adapted to house the spring 31 when the thrust washer 30 is pressed against the abutment member 32. i

The elements so far described are maintained in assembled position on shaft 10 by suitable means such as a stop nut 34 threaded on the endportion 16 of said shaft and suitably retained thereon as by means of a cotter pin 35 engaging in castellations 36 of said nut.

A drive member which is here shown in the form of a pinion 37 is loosely threaded on the actuating member 17 and adapted to be moved thereby into and out of engagement" with a. member of an engine to be started such as a'fiywheel gear, a portion of which is indicated at 38. Pinion 37 has a hub portion 39 extending laterally therefrom into the plane of the engine member 38 and into proximity to the anti-drift member 30 which is also located in the plane of said engine member. Pinion 37 is thus yieldably prevented from drifting into engagement with the engine member 38 while the engine is running by the anti-drift means comprising the spring 31 and thrust washer 30. Motion of said pinion away from engaging position is limited by the heel 17 (Fig. 5) of thread 17 on actuating member 17, which is adapted to cooperate with a suitable conformation in the end of pinion 37 to form a back stop for said pinion. As illustrated in Fig. 3, the meshing position of pinion 37 is determined by the abutment member 32 which limits the motion of pinion 37 into engagement with the engine member 38.

The thread 17 on actuating member 17 may if desired be formed with apitch which is so low as to be irreversible, so that endwise pressure alone on the pinion is ineffective to move the pinion along the actuating member. This arrangement is advantageous in that it resists any tendency for relative wheel should overrun sufiiciently to cause the pmlon 37 to overrun the actuating membcr 17, it would be the actuating member that would move back and forth in the bore of the pinion, while the latter is held in fully meshed position by virtue of the pressure of spring 20. g

In operation, and starting with the parts as illustrated in F ig. 1, rotation of shaft 10 in a clockwise direction as viewed from the left in Fig. 1 will cause the pinion 37 to be moved to the left by reason of its inertia and its threaded engagement with the actuating member 17. The pinion is thus caused to enter into meshing relation with the engine member 38 until the endwise motion of the pinion is stopped by the abutment member 32.

rotated by pinion 37 and the engine cranked l) thereby. Spring 20 is so designed as to suitably control the. rate of deceleration of the driving shaft 10 so as to efliciently utilize the kinetic energy stored in the armature to as- Leo sist in initiating the rotation of the engine 1.2..

member. 7

When the engine starts, the engine member 38 is accelerated and causes the pinion 37 to overrun the actuating member 17 whereby said actuating member is allowed to return to its normal position under the impulse of

springs

20 and 21 and thereafter pinion 37 is returned to its normal position on said actuating member as defined by the heel 17 of the thread 17', and is retained therein by means of the anti-drift spring 31 and thrust member 30.

In case, during a starting operation, the teeth of the pinion 37 should engage end to end against the teeth of the engine member 38 thus interrupting the motion of the driving member toward meshing position, the actuating member 17 will be moved slightly to the right as shown in Fig. 4 against the resistance of the light compression spring 21. This spring is arranged to be sufiiciently limber so that the engagement of the teeth of

members

37 and 38 is adequately cushioned and is therefore without destructive effeet. As the pressure between the actuating member 17, pinion 37, and engine member 38 builds up during the compression of spring 21, the friction between the actuating member and pinion increases until it exceeds the friction between the pinion and engine member. The pinion thereupon rotates slightly with the actuating member into registering position with the tooth-spaces of the engine member 38. Spring 21 then expands and initiates the meshing engagement of the pinion and engine member. It will be understood that the time interval required to compress the spring 21 is sufiicient to allow this indexing action of the pinion to take place. Further rotation of the driving shaft 10 causes completion of the meshing engage ment and subsequent rotation of the engine member as above described.

It will be noted that during the cranking operation, both of the

light springs

21 and 31 are completely housed, the former being enclosed within ,the thimble 24 and thrust member 23. and the latter between the abutment member 82 and the thrust washer 30,

. whereby it is impossible for centrifugal force to cause deformation of the springs. It will further be noted that the shoulder 28 of stop sleeve 27 is adapted to retaifnthe annular thrust Washer 30 on said, sleeve even though the actuating member 17 and pinion 37 should momentarily back out of contact with said sleeve. Such a condition might possibly occur during handling of the motor and drive assembly, when the spring 21 might be compressed sufficiently to allow the thrust washor 30 to fall back of the end of stop sleeve 27 and lock the pinion in its retracted position. The arrangement of the shoulder 28 is also advantageous in maintaining the wash er 30 on the sleeve 27 during the operation of assembly.

Although but one form of the invention has been shown and described in detail, it will be understood that other embodiments are possible and that changes may be made .in the construction and arrangement of the parts without departing from the spirit of the invention.

Reference will therefore be had to the actuating member toward the engine mem-' ber, and yielding means mounted on said stop for normally maintaining the driving member out of engagement with the engine member.

2. In an engine starter drive, aemember adapted to engage and drive a member of the engine to be started, an actuating mem ber having connections with said driving member whereby relative rotation causes relative translation thereof, yielding means for lightly opposing initial longitudinal movement of the actuating member away from said engine member, yielding means for strongly resisting further such longitudinal movement of the actuating member, means whereby the reaction of said light opposing means is transmitted'through said resisting means While allowing the actuating member to act directly on the resisting means after said initial movement thereof, a stop for limiting longitudinal movement of the actuating member toward the engine member, and yielding means mounted on said stop for normally maintaining the driving member out of engagement with the engine member, said stop having means for retaining said yielding means thereon in all operative positions of the drive.

3. An engine starter drive including a driving shaft, an actuating member mounted thereon for longitudinal movement thereof and rotary movement therewith, a stop sleeve for said actuating member mounted on said shaft, yielding means normally maintaining said actuating member against said stop, a driving member mounted on said actuating member for longitudinal movement thereon to engage a member of the engine to be started, said shaft having an abutment for said driving pinion which is recessed immediately adjacent said sleeve, and a yielding thrust member mounted on said sleeve and interposed between said driving member and said abutment. V

4. An engine starter drive including a driving shaft, an actuating member mounted thereon for longitudinal vmovement thereof and rotary movement therewith, a driving member mounted on said actuating member for rotary movement thereon and therewith and for longitudinal movement into and out of engagement with a member of the engine to be'started, a fixed stop for said actuating member in the plane of said engine member, yielding means for normally maintaining said actuating member against said stop, a yielding anti-drift element for said driving member mounted on said stop in the plane of the engine member, said driving member having a hub extending into proximity to said anti-drift element when said driving member is in its normal inoperative position.

5. An engine starter drive including a driving shaft, an actuating member mounted thereon for longitudinal movement thereof and rotary movement therewith, a stop sleeve for said actuating member mounted on said shaft, a driving member mounted on said actuating member for longitudinal movement thereon and rotary movement therewith to engage and drive amember of the engine to be started, said shaft having an abutment for said driving pinion which is recessed immediately adjacent said sleeve, and a coiled spring encircling said sleeve and interposed between said driving member and the abutment, with the coils at one end received by said annular recess, said spring extending into the plane of the engine member, and said driving member having a hub extending into proximity to the end of said spring when said driving member is in its normal inoperative position.

'6. In an engine starter drive, a driving shaft, a hollow sleeve splined thereon, a driving member threaded on said hollow sleeve and adapted to automatically engage and drive a member of the engine to be started, a stop for limiting movement of' the hollow sleeve toward the engine member," yielding means opposing movement of the hollow sleeve away from the engine member, and yielding means on said stop normally maintaining said driving member out of engagement with said engine member.

7. In an engine starter drive, a driving shaft, a hollow sleeve splined thereon, a driving member threaded on said hollow sleeve and adapted to automatically engage and drive a member of the engine to be started, a stop for limiting movement of the hollow sleeve toward the engine member, yielding aneans opposing movement of the hollow sleeve away from the engine member, an annular member loosely mounted on said stop adapted to engage the driving member, yielding means urging said annular member in a direction to maintain the driving member out of engagement with said engine member, and an abutment for said annular member limiting the engaging movement of said driving member.

8. In anengine starter drive, a driving shaft, a hollow sleeve splined thereon, a driving member threaded on said hollow sleeve and adapted to automatically engage and drive a member of the engine to be started, a. stop for limiting movement of the hollow sleeve toward the engine member, yielding means opposing movement of the hollow sleeve away from the engine member, an annular member loosely mounted on said stop adapted to engage the driving member, yielding means urging said annular member in a direction to maintain the driving member out and adapted to automatically engage and drive a member of the engine to be started, a

stop for limiting movement of the hollow sleeve toward the engine member, yielding means opposing movement of the hollow sleeve away from the engine member, an annularanti-drift member loosely mounted on said stop adapted to engage the driving member, yielding means urging said annular mem ber in a direction to maintain the driving member out of engagement with said engine member, said stop having means for retaining said annular member thereon, and an abutment for said annular member limiting the engaging movement of said driving member.

10. In an engine starter drive, a driving shaft, a threaded sleeve splined thereon, a pinion threaded on the sleeve for longitudinal motion into and out of engagement with a member of the engine to be started, a stop for limiting the engaging movement of the pinion, a light spring and a heavy spring arranged to oppose longitudinal movement of the sleeve away from the engine member, the heavy spring being normally spaced from the sleeve and adapted to engage the same after a predetermined compression of the light spring.

11. In an engine starter drive, a driving shaft, a threaded sleeve splined thereon, a pinion threaded on the sleeve for longitudinal motion into and out of engagement with a member of the engine to be started, a stop for limiting the engaging movement of the pinion, a light spring and a heavy spring arranged to oppose longitudinal movement of the sleeve away from the engine member, said springs being telescoped one within the other, and means to place the spring functionally in series with each other.

12. In an engine starter drive, a driving shaft, a threaded sleeve splined thereon, a

pinion threaded on the sleeve for longitudinal motion into and out of engagement-with a member of the engine to be started, a light spring and a heavy spring arranged to oppose longitudinal movement of the sleeve away from the engine member, said springs being telescoped one within the other, and a thimble located between said springs adapted to connect them end to end and arranged to connect the heavy spring directly With the sleeve after a predetermined compression of th: light spring.

In testimony whereof we have signed this specification.

WILLIAM L. MGGRATH. MAURICE P. WHITNEY.