US1531351A - Starting crank - Google Patents

Description

March 31, 1925.

G. G. SMIT?,

STARTING CRANK Ellelhlgay 2. 1923 Patented Mar. 3l, 1925.

c UNITED STATES PATENT oFF Ica.; l

` STABTDQ'G CRANE.

Application led Hay 2, 19.23. Serial No. 633,163.

To all 'whom it concern:

Be it known that I, GEORGE a citizen of the United States Franklin, in the county of Southampton, in the State vof Vir ima', have invented a certain new and use l Starting Crank, of which the followin is a specification.

The invention r atcs to certain new and useful improvements in starting cranksof that particular type wherein is embodied safety features for reventing injury tc the user under kickback action of the engine.

In ex lesive engines, upon actuation of the cran ing device adapted to cause rota tion of the engine shaft to reciprocate the engine piston .for the purpose of drawing into the cylinders and compressin therein the combustible mixture to effect t e initial explosion and start of operation of the engine, it is a common experience, from one cause or another, for a. reverse action of the crank shaft to occur when initial explosion takes place, which causes a severe backward force to be exerted upon-the arm of the operator which is apt to cause serious injury. I f

It is therefore the ob'ect of my invention -to provide a cranking evicye of the character stated and -in the structure of which is included .sa-fet means whereby this kickback actionvo the engine shaft may take place without any jurious effect whatever upon the arm of the operator.

With the above and other ob'ects in view that will hereinafter ap ear t e invention resides in those novel dgtails of construction, combination of and arrangement of parts, .all of which will be first fully described and particularl pointed out in the appended claims and ilustrated in the ac- G Samia, residing at :companying drawing in which:

Figure 1 is a cross section taken through the crank portion of my device and looking in the direction of the engine shaft. e

'Figure 24 is a central longitudinal section 'of my device, a portion of an engine shaft bein indicated 1n dot and dash lines and the ocking key being'shown retracted in dotted lines. A

Figure 3 is a. detail cross section 'taken on the line 3 3 of Figure 2.

' Figure 4 is a detail perspective view illus trat' the ratchet w eel member and the cam hed thereto..

lshaft of `usual crank pin 2.

`the engine shaft (when in its Figure 5 is .a detail perspectiveview of the Il locking key member.

vIn tie drawing, 1 indicates. the en any conventional type of com iistion engine and which is provided with th'e In the practical embodiment of my invention I provide a crank handle member 3 which is provided, integral therewith, with a crank portion 4 in the nature of a; cylindrical shaft, in longitudinal alignment with t5 operative position) and which has its end bifurcated as at 5. A stop lug 6 is secured within the inner end of the bifurcation 5 by cross pins as shown, and the said stop lug proyecta 'I0 from the said bifurcation in a manner and for a purpose soon to be described.

Loosely mountedu on the crank portion 4, to be freely rotatagle thereon, I rovide a ratchet wheel 'Z' which is adapted) to be 75 positioned closely adjacent the stop lug 6. A cam member 8 is secured to the ratchet wheel 7, as by the use of screws 9, or made integral with the ratchet wheel, and the Said cam member' includes a heel portion 'l0 80 adi pted to be normally held against the sto lug 6 by a light tension spring 11 secur to the posts 12 and 13 of the stop and the cam member respectively. The cam member also includes a cam face 14, the purpose of as which will presently appear. Loosely mounted upon the end of the crank portion 4,. to freely rotate thereupon at intervals, I provide a crank hub y15` and the said hub is adapted to lie closely adj cent the ratchet wheel 7 to be held fromlo gitudinal removal from the crank portion, 4 thereby and by reason of the retainin' plate 16 Secured to the end of the vcran'- portion 4 by the screws 17 as shown. rlhe it crank hub 15 includes a cranking extension 18 secured thereto in any desired manner, or formedintegral therewith, and the' said cranking extension is provided with the usual o positely dislpsed crank grooves 19 100 adapted) to engage t e crank pin 2 of the en lne shaft during the cranking operation'. etweeuthe outer bifurcated end-'ofthe crank portion 4 I mount a locking key meinber 21 pivoted on a cross pin 22 and which 106 is'provided with a key ortionfor engi!k inge keyway 2O form inthe crank u `15 a cutout portion 23 to accommodate rotation of the ratchet Wheel 7, and a key head 24 having a bevelled face 25 adapted to be in position for being engaged at times, by the cam face 14, in a manner and for the purposes soon to be described.

A. spring l26, secured in any approved inanner within the bifurcation 5, acts to hold the locking keyV member outwardly in locking relation with the key-way 20 in the crank hub 15.

Pivotallymounted upon a bracket 27, secured to the engine supporting frame in any approved manner and 1n position for properly engaging with the ratchet Wheel 7, l

rovide a check pawl 28 which is adapted to be held in engagement with the beforementioned ratchet wheel by a spring 29.

By reason of the foregoing it wiltbe readily a parent that by applying m improved cran ing device to the e ine s aft oi the engine adapted to be cranked in the usual manner and by applying rotary motion of the said crankin a clockwise direction, the key member 21 being in enga ement with the keyway 2O of the crank hu 15, the desired rotary motion will be imparted to 'the ting rotation of engine shaft, y

Thus far the action of my device is exactly the same as though the crank handle, the crank portion and hub were all one part as is the case ,in the common crank handle.

Therefor, it is understood that in this normal position of .my invention the back check pawl 28 is in engagement with'the ratchet wheel 7 and in a manner for permitthe cam member in a clockiWise direction. This rotation of the ratchet wheel in the clockwise direction, during the cranking action, is effected by the engagement of the stop luv' 6 with the heel portion 10 of the cam mem er.

Whenever a kick-back action of the engine shafttakes place the back check pawl 28 immediately acts to prevent counter-clockwise rotation of the loosely mounted ratchet wheel PLand, as the crank tends to turn in such counterclockwise direction by reason of the ke and keyway connection 20-21 between t e crank portion 4 and the crank hub 15, such rotary motion of the crank portion 4, relative to the now stationary position 'of the ratchet wheel 7, `causes the lug 6 to leave the heel portion 10 of the cam member, against the action of the spring 11, and with the effect of causing the cam face 14 of the said lcam member 8 to engage thebevelled face 25 of the key head 24 to remove the key 21 from the reyway 2() to thus permit free rotation of the hub 15 upon the crank portion 4.

This action, of releasing the crank hub 15 from the key locked condition with the crank portion 4, is instantaneous in its action so that the said crank hub 15 may freely "rotate, under action of the kick-back of the meneer engine shaft without in any manner effecting the crank portion or the arm of the operator en aging the handle portion 3. It will be rea il understood that the spring connection 26 etween the lug 6 and the com member 8 will bring those parts to normal position after the arts have functioned to pro-erly provide or the kick-back action, so t at the parte may be again returned to normal position for another cranking operation.

While i have shown and described a ractical embodiment or my invention I esire to have it understood that such changes in the details of construction and arran ment of parts may be made as Will be desired to A adapt the invention to other uses than those described herein and which come within the sco e oi the appended claims.

rom the tore oing description, taken in connection with t e accompan ing drawing, it is believed that the novel stalls of construction, the operation and advantages of my invention will be readily ap arent to those skilled in the art to which t e invention relates., I

What li claim is: i

1. A readil removably mountable device of the class escribed comprising; a crank member including a handle portion and a binrcated crank portion; a hub loosely mounted on the crank portion having an extension for engaging the engine shaft and an internal key-way; a retainer plate secured to the bifnrcated crank portion to engage the hub; a stop lug secured in the biurcation of the crank portion; a ratchet wheel loosely mounted on the crank portion, a cam member carried by the ratchet wheel and havin an inwardly directed cam face and a stoptlieel; a sprin for normally holding the cam member heein engagement with the stop lug; a key member pivoted in the bifurcation of the crank portion and having a key portion for engaging the hub keyway, a recess for straddllng the ratchet wheel and a bevelled head to be acted on by the cam face; a spring normally forcing the key member to the hub engaging positlon; and;

a spring pavvl for acting on the ratchet Wheei to prevent back rotation thereof.

2. A. readil removably mountable device of the class escribed comprising; a crank member including a handle portion and a biturcated crank portion; a hub loosely mounted on the crank portion having an extension 'engaging the engine shaft and an internal keyway; a retainer plate secured to the bifurcated crank portion to engage the hub; a stop lug secured in the bifurcation of the crank portion; a ratchet wheel loosely 'mounted on the crankportion; a cam member carried by the ratchet Wheel and having an inwardly directed cam face and a stop heel; a spring for normally holding the cam member heel in engagement with the stop spring pawl for acting on the ratchet wheel lug; a key member plvoted in the bifurcato .prevent back rotation thereof; and a 1oy tion of the crank portion and having a key bracket carrying the pawl and having a portion for engaging thc hub keyway, a stop Egrtion preventing movement of the' 5 recess for straddling the ratchet wheel and pawl` ,youd the depth 0f the ratchet Wheel a bevelled head t0 be acted on by the cam teeth. face; a spring normally forcing the key member to the hub engaging position; a GEORGE GREGORY SMITH.

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