US1500781A - Safety device for engine cranking - Google Patents

Description

July 8, 1924'. 1,500,781

F. E. TURNER SAFETY DEVICE FOR ENGINE CRANKING Filed Jan. 29 1923 INVENTOR. Francis E. Turner ATTORNEY Patented July 8, 1924.

FRANCIS E. TURNER, F CRESCENT CITY, CALIFORNIA.

SAFETY DEVICE FOR ENGINE CRANKING.

Application filed January 29, 1923.

,To all whom it may concern:

and useful Improvements in Safety Devices for Engine Oranking; and I do declare the following to be a full, clear, and enact description of the same, reference belng had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application.

This invention relates to improvements in safety devices for use in connection with the cranking of-gas engines by hand, an opera- .tion which must still be done with the engines of most automobiles of a certain popular make.

The principal object of my invention isto. provide a means for preventing a reverse rotation from the normal of the crankshaft of the engine, due to what is commonly known as backfiring, from being imparted to the cranking handle, which is of course in operative connection with the crankshaft duringthe cranking operation.

Such a sudden reversal of movement as takes place with a backfire, if transmitted to the cranking handle, is very often the cause of broken arms and other accidents, and the purpose of my device is to eliminate .suc unfortunate occurrences. v V

Another object of my invention is to provide a device for the purpose which may be very easily applied to the car, with only the alteration of a singleoriginal part or its replacement by another made especially, being necessary.

A further object of the invention is to producea simple and inexpensive device and yet one which will be exceedingly eflective for the purposes for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of.

the following specification and claims.

In the drawings similar characters of ref erence indicate corresponding parts in the several views.

I Fig. 1 is a fragmentary outline of the front of an automobile, showing my .improved safety device installed thereon.

Fig. 2 is an enlarged sectional elevation of the device and cranking apparatus, detached and showing the same in the normal cranking position.

tate

Serial .No. 615,560.

F 3 is a similar view, showingthe-posie tioning of the parts aftera-Tkickback of theshaft has taken place.

Referring now more particularlyto the characters of reference on thedrawings, the

numeral 1 denotes the usual transverse spring supportmg member of thelcar, which supports the front spring 2,, U-clips 3 being employed to bind the spring and support together, the clipsalso securing a bearing member. l'in which the cranking shaft ,5; is slidably andturnably journaled.

This shaft as usual, carries onits inner end a notched member 6 adapted to 'be placed into detachable engagement with a transverse pin 7 on the outer end of the engine crank shaft 8.

Theouter end of theshaft is threaded righthand for a certain distance as shown at 9, and threaded onto this portion is a ratchet wheel 10 engaged by ,a pawl 11 pivoted on a plate 12 mounted inconnection with the member 4 and one of the clips 3, the ratchets and pawl beingso disposed that the wheel may turn freely a clockwise direction but is held from rotation in the opposite direction.

The usual spring 13 is placed about the shaft between the members land 10, and acts to move the shaft 5 away from the shaft 8.

Placed snugly on said shaft 5 outwardly of the member 10 is a thin narrow ring 14 and outwardly of the ring the upper end 15 of the cranking-handle member 17 is threaded on to the shaft. 7

A retaining nut 17 is screwed on to the outer end of said shaft 5, being held against movement by any suitable means, this nut acting to prevent removal of the handle member.

In the operative positions of the parts the handle member 15 is snug against the outer nut 17, the ring 14.. is snug-against the opposite face of the handle member, while the ratchet wheel 10 is snug against the opposite face of the ring, leaving a certain number of the threads 9 unoccupied beyond the wheel 10, or towardthe bearing l.

If then the handle is rotated inthe customary clockwise orright hand direction,

its tendency is to move along the shaft, following the threads. This, however, it cannot do owing to the member 10 in its path of movement, this member, besides being a ratchet wheel, is in efiect a lock or stop nut, keeping the handle member in said members,

definitely apart, and yet has such a small bearing surface that any tendency of the *would not of course turn.

This undesired result is preventedby the interposition of the narrow ring 14 between which holds the two nut 10 to turn on'the shaft is eliminated,

and it then performs its function as a stop to prevent similar movement of the handle member. The result therefore, is that the shaft 5 is turned, and the member 10 turns with it without moving along said shaft, the pawl 11 offering no resistance to move- .ment of the wheel 10 in that direction.

' If however the shaft 5 kicks back, the

member 10 is immediately prevented from turning back with the shaft by reason of the pawl 11, the result being that the member 10 is caused to move along the shaft in the i only direction which the cut of the threads 9 will permit, which is away from the ring 1 1 and handle portion 15. 'i

This of course effectively breaks the seal or flOCk' between the above named three members, leaving the handle member, which is still grasped by the hand of the operator and thus resists being turned backwards, free to also move along the shaft with the tendency to so move imparted thereto by the backward rotation of the shaft, instead of its turning with the shaft and possibly breaking the arm of the operator.

After such a back-kick, the members 10 and 1.5 should be retracted to the original positions as described hereinbefore, before again starting cranking operations.

From the foregoing description it will be readily seen that I have produced such a -device as substantially fulfills the objects of the invention as set forth herein.

l/Vlnle thls specificat on sets forth indetail the present and preferred col'lstruction of the' device, still in practice such deviations fromsuch detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful and desire to cure by Letters Patent is:

1. A safety cranking device for gas engines comprising ashaft adapted to be operatively connected to thecrank shaft of 'tation thereof, a

the engine, the outer end of said shaft being threaded in the direction of normal rocrank-handle member threaded on to said shaft, a stop member threaded on to the shaft inwardly of the handle member, said stop member beins. normally positioned to prevent movement of the handle member along the shaft in that direction, and means preventing rotation of the stop member with the shaft other than in the direction of normal rotation of the latter, whereby when a reverse-direction movement is imparted to the shaft the stop will be automatically caused to move along the shaft and away from the handle member.

2. A safety cranking device for gas engines comprising a shaft adapted to be operatively connected to the crankshaft of the engine, the outerend of said shaft being threaded in the direction of normal rotation thereof, a crank-handle member threaded on to said shaft, a stop member threaded on to the shaft inwardly of the handle member, and free to rotate with the shaft only in the direction of normal rotation of the latter, and means on the shaft between the handle and stop member for preventing longitudinal movement" of the handle member on the shaft and for pre- 7 venting the turning of the two together 011 the shaft;

3. A safety cranking device for gas engines comprising a shaft adapted to be operatively connected to the crankshaft of the engine, the outer end of said shaft being threaded in the direction of normal rotation thereof, a crank-handle member thread ed onto'said shaft, a stop member threaded on to the shaft inwardly of the handle member, and free to rotate with the shaft only in the direction of normal rotation of thelattcr, and a spacer ring having relatively small bearing area fitted on the shaft between the stop and handle members.

f. A safety cranking device for gas engines having a shaft adapted to be operatively engaged with the crank-shaft of the engine, comprising a handle member threaded onto said shaft, the threads running in the direction of normal rotation of the/shaft, a stop member threaded onto the shaft inwar lly of the handle member, ratchetteeth cut in the periphery of said stop member, a fixed pawl engaging the same, and a spacer ring having relatively small bearing area fitted on the shaft between the stop and handle members.

In testimony whereof I affix my signature.

FRANCIS E. TURNER.

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