US3149621A

US3149621A - Turning device for rotatable shafts

Info

Publication number: US3149621A
Application number: US62567A
Authority: US
Inventors: Earl E Bailey
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-10-14
Filing date: 1960-10-14
Publication date: 1964-09-22
Anticipated expiration: 1981-09-22

Description

Sept. 22, 1964 lE. E. BAILEY vTURNING DEVICE FOR ROTATABLE sHAFTs Filed Oct. 14, 1960 5 Sheets-Sheet 1 [ar/ f. a//ey /fw M INVENTOR.

Wam/W Wfw Sept. 22, 1964 EYE. BAILEY 3,149,621

` TURNING DEVICE AFOR ROTATABLE SHAFTS Filed Oct. 14, 1960 5 Sheets-Sheet 2 ff/ f. 50//95/ INVENTOR.

Sept. 22, 1964 E. E. BAILEY TURNING DEVICE FORROTATABLE sHAFTs 5 sheets-sheet s v Filed Oct. 14, 1960 [of/ f. 9a/Vey IN V EN TOR.

sept. 2,2, 1964 E. Bamm 35149521 TURNING DEVICE vFOR ROTAT'ABLE sHAFTs Filed ont. 14, lsaeoA v 5' sheet'ssneet 4 i faf/ f. Sai/ey INVENToR.

Sept. 2 2, 1964 E. E. BAILEY 3,149,621

TURNING DEVICE FOR ROTATABLE sHAFTs Filed oct. 14, 1960 5 Sheets-Sheet 5 faf/ f. 9a/Vey INVENTOR United States Patent O 3,l49,621 TURNING DEVICE FR RGTATABLE SHAFTS Earl E. Bailey, 814 Lyngrove Drive, Houston, Tex. Filed Oct. 14, 1960, Ser. No. 62,567 l2 Claims. (Cl. 123 i.79)

This invention relates to a turning device for a rotatable shaft and, more particularly to a spring starting mechanism for an internal combustion motor of the type having a rotatable shaft which may be utilized to spin the motor and start it in operation.

Many internal combustion engines of a low horsepower output are equipped with a standard hand-operated pull cord by means of which an operator spins the motor shaft to start the engine. The hand-operated pull cord has many disadvantages, which have inspired devices that may be secured to the engine to start same as a substitute for the hand-operated pull cord. ln general, these mechanisms are of the type having a spring which may be wound to a desired tension and then released to spin the motor shaft to start the engine. At the present time these mechanisms have met with a favorable reception by users of small internal combustion engines; however, even these mechanisms have certain disadvantages. The most major one is that the spring must be reset manually.

A number of mechanisms featuring a spring which may be wound and selectively released to spin the motor shaft to start an engine have been proposed, which also include some means of using the engine after it is operating to rewind the spring. complex mechanical elements which were found necessary to automatically control the resetting of the spring after it has been utilized to start the engine. The automatic control is usually provided by a timing device that determines the number of turns the spring is wound. ln general, the spring starting mechanisms having automatic resetting features have required a plurality of shafts or their equivalents with the result that the mechanism was complex mechanically and diticult to manufacture economically. These features prevented their acceptance by users of the internal combustion engine as a substitute for the type of spring starting mechanisms having manual spring resetting features. An additional disadvantage resides in that the resetting of the spring in such mechanisms is not a positive operation, i.e., the drive connecting means with which the winding mechanism was connected to the engine shaft did not positively engage or disengage and resulted in chattering of clutch members, or the like, and naturally resulted in accelerated wear and destruction of such drive connecting means.

The above defects have, in general, limited the known spring starting mechanisms to those in which the spring isrewound manually and therefore usable only on small internal combustion engines.

It is therefore an object of the present invention to provide a mechanical turning device for a rotatable shaft that is simple to operate, durable, compact and inexpensive to construct, and that is especially suited for use in starting internal combustion engines, large or small.

Another object is to provide a satisfactory spring starting mechanism for internal combustion engines, which after being set can be operated to start such engine and after the engine is operating through movement of the spring to be automatically reset for future use.

A further object is to provide a spring starting mechanism for internal combustion engines that is positive in its operation, both in starting such engine and after the engine is operating in the automatic resetting of the spring for future use.

Another further object is to provide in spring starting mechanisms fulfilling the preceding objects, a means These mechanisms have featured fairly lCC whereby the spring may be reset manually should the engine fail to start.

Another object is to provide a spring starting mechanism for internal combustion engines in accordance with the preceding objects that is easily attachable to existing internal combustion engines and does not require permanent structural modilications of such engines.

These and other objects of the invention will become apparent from the following description when read in conjunction with the accompanying drawings in which:

FIG. l is a side elevational View of a rotary type lawn mower on which the turning device of the present invention is mounted;

FIG. 2 is enlarged side elevational view partially in section showing the turning device of FIG. 1 in greater detail;

FIG. 3 is a sectional View taken along 3 3 of FIG. 2;

FlG. 4 is a sectional View similar to FlG. 3 showing the operating plunger in spring locking position.

FIG. 5 is a partial sectional view taken along line 5 5 of FIG. 3;

FIG. 6 is a partial sectional view taken along line 6 6 of FIG. 3;

FIG. 7 is a partial sectional View taken along line 7 7 of FIG. 3;

FIG. 8 is a partial sectional view taken along line 8 8 of FIG. `3;

FIG. 9 is a partial sectional view taken along line 9 9 of FIG. 3;

FIG. 10 is a partial sectional view taken along line N il of FIG. 3;

FIG. ll is a partial sectional view taken along line ll-li of FIG. 3;

FIG. l2 is a sectional view taken along line 12-12 of FIG. 2;

FIG. 13 is a sectional view taken along line 13a-13 of FIG. 2; and

FIG. 14 is an exploded perspective view illustrating the snap action means of the present invention and the clutch shifting fork that engages and disengages the clutch parts.

For the purpose of describing the present invention, the turning device will be illustrated and described in conjunction with its use for rotating the crankshaft of an internal combustion engine of the type commonly used onrotary lawn mowers, such as illustrated in FIG. l. It is to be understood, however, that the turning device may be used to rotate the rotatable shafts of other types of devices where it is desired to use the turning device to initially rotate a rotatable shaft and after the shaft is rotating due to some other power source, to use the shaft to restore the turning device to a condition whereby it may be used again.

For convenience in the description of the present invention, the turning device will be described as being comprises of Four Basic Elements, all of which, however, are combined into a unitary device. These elements are:

(l) A spring case stationary with respect to the rotatably mounted a spring shaft about which a spring is positioned within the case and arranged so that the spring may unwind to rotate the spring shaft in one direction and rotation of the shaft in the other direction will rewind said spring, and means connected to the spring shaft whereby a driving connection may be made between the spring shaft and rotatable shaft for rotating the last-mentioned shaft in said one direction;

(2) A rewinding means connected to the spring shaft for rotating the spring shaft in a direction reverse to said one direction to wind the spring;

(3) A clutch means interposed between the rewinding means and the rotatable shaft whereby it maybe engaged to provide a drive connection between the rewinding amasar means and the rotatable shaft so that the spring may be rewound; and l (4) A clutch engaging means connected to the spring intermediate its ends and adapted to engage and disengage such clutch means in response to movement of the spring as its tension is changed during winding and unwinding, whereby the clutch engagement means will automatically engage the clutch means as the spring is unwound so as to effect a rewinding of the spring, and will automatically disengage the clutch means as the spring becomes nearly fully wound. Tl e basic elements will be described in their above-listed order for convenience and in an effort to provide a more clear description of the present invention.

Reference is now had to FIG. 1 of the drawings wherein, for the purposes of illustration, there is shown a preferred embodiment of the present invention secured to a rotary lawn mower 2li powered by an internal combus tion engine 2l of the conventional design. T he engine 2i has a vertically disposed crankshaft ZZ at one end of which is secured a blade 235 with the turning mechanism of the present invention, generally designated by numeral 24', secured to its other end. The turning device 124 is supported in operable position with respect to the engine 21 by means of legs 27 or the like on the metal dust cover Z of mower Ztl. rl`he legs 27 may be secured to the turning mechanism and the dust cover 25 in any convenient manner.

Basic Element (1 Referring to FG. 3, a more detailed description of the preferred embodiment of the turning mechanism Zd of FIG. 1 will be given. The Easic Element (1) of the turning mechanism 241 is comprised of 26 which is mounted stationary with respect to the engine mount by means of legs 27, as has heretofore been described. A spring shaft 29 is rotatably mounted within the case in any convenient manner and extends therefrom. In the embodiment specifically illustrated, t te shaft is rotatably mounted by a bearing which is provided by an annular recess 2,912 formed within shaft 29 into which is received an inwardly projecting portion 26a of case 26. A spring 28 is operably positioned within case 26 and extends about spring shaft 29. The spring 23 has one of its ends secured to case 2e and the other end is secured to spring shaft 29 in any convenient manner. The spring 28 is arranged in such a manner that when it is wound it can rotate the spring shaft Z9 in one direction and when the shaft 29 is rotated in the opposite direction the spring 28 will be rewound or reset. For descriptive purposes the said one direction will be a countercloekwise direction of rotation of shaft 29 when viewed in the relationship shown in FIG. 11.

A locking means is provided whereby the spring shaft 29 may be held stationary with respect to case 26 so that the spring may be wound and held under tension in this position until it is desired to be released and rotate the spring shaft in said one direction. This locking means is provided in the illustrative embodiment by the arrangement of an operating plunger Si) which extends axially into spring shaft 29. A knob 31 is secured to the eX- posed extremity of plunger 3@ to facilitate it being easily grasped by the hand of the operator. An annular groove 32 is provided adjacent the inner extremity of plunger 3ft. A plurality of balls 34 are mounted in a passageway 33 extending radially outwardly through spring shaft 29 so that when plunger 36 is moved downwardly as viewed in FIG. 3 balls 34 will move radially inwardly due to the tapering surface 32a until they seat in groove 32. When the plunger is moved upwardly as viewed in FIG. 4 due to the bias of spring 36, the balls are forced radially outwardly by tapering surface 32a so that they will assume the position shown in FIG. 4 and can engage recess 35 in a second internal gear wheel di?. Internal gear wheel 40 is provided with means to prevent it from being rotated in said one direction by the spring shaft 29 and thereby locking the spring shaft relative to the case. Thus, when the plunger is depressed to the position shown in FIG. 3, balls 34 recede into groove 32 and thereby free spring shaft Z9 so that it may rotate in said one direction due to the tension of the spring and when the plunger 3Q is returned by spring 3f: to the position shown in FIG. 4, spring shaft ZE' is locked relative to the case and movement in said one direction cannot result.

Once the operating plunger 3% is depressed, it Vmay be released but will not return to its upward position because the balls 34 will not be displaced outwardly sufficiently to engage recess 35 in member 46 until the speed at which shaft 29 is rotating decreases and approaches the speed at which second internal gear wheel 4t) is rotating. lt is only under such conditions that spring 36 can urge plunger upwardly with sufcient bias that tapered surface 32u can cam balls 34 into recess 35 thereby locking shaft 29 to internal gear wheel rihis, of course, locks shaft 29 and gear it? together without a great deal of strain being exerted on balls 3e or recess 35, and avoids having to hold plunger Si@ down throughout the starting cycl A means by which a driving connection is made between the spring and rotatable shafts whereby the spring shaft rotate the rotatable shaft in said one direction is provided by means of a cylindrical housing 37 which is reieasabiy secured to shaft 22 by means of nut 38 so that the housing 37 is carried on engine shaft 22.. A plurality of pawls 33"? are pivotally mounted within housing 37. rfhe extremity of spring shaft Zi? adjacent the engine shaft 22 is provided with a notched surface 29a so as to form a rachet wherein the pawls 39 may engage. This is most clearly shown in FIG. 11. The pawls 39 are resiliently urged by springs 3% into engagement with the rachet surface 29a of shaft Z9. This arrangement of the pawls 39 permits the shaft 29 to turn the crank shaft 2E in said one direction and will permit the pawls to be disengaged from shaft 29 after the engine is operating under its own power. The pawls of course will be forced outwardly out of disengagement with shaft 29 under such conditions. This arrangement provides an effective drive connection so that the spring shaft may rotate the rotatable shaft in said one direction but not in the reverse direction. Th resilient means or springs 39a will force the pawls 39 into engagement with shaft Z9 whereby a condition exists so that shaft 29 may rotate shaft 22 upon the engine 2i being stopped.

rThe engine is started when the spring is wound and under tension and the spring shaft 29 is locked to second internal gear wheel 40. It is started by depressing plunger 3b so that balls 34 recede into groove 32. thereby unlocking shaft 2.9 from gear wheel 4@ whereby shaft 29 is rotated by spring 23 in said one direction. Such rotation is transmitted to shaft 22 through the drive connection means comprised by pawls 39 in cylindrical housing 37 engaging the ratchet surface 29a of shaft 29. This arrangement of the shaft 29 with respect to shaft 22 in the first element is of particular utility in this invention as it is most desirable to rotate shaft 22 by means of shaft 2i at the highest possible rotary speed in order to be able to successfully start even the most balky internal combustion engines with which it is used. Thus, such a direct transmission of torque from the spring 29 to shaft 22 is achieved. Other means for locking shaft 29 relative to case 26 and for providing a drive connection between spring shaft 29 and crankshaft 22 may also be used, as will be apparent to a person skilled in the art.

lt is seen that this arrangement of the case and spring shaft 29 permits the spring shaft to extend outwardly from only one side of the case 26 and thereby provide a more compact unit than otherwise possible.

Basic Element (2) The Basic Element (2) of the turning device of the present invention is a rewinding means which s connected to the spring shaft whereby the spring shaft may be rotated in a direction reverse to said one direction of rotation, whereby the spring may be rewound. It is preferable that the speed of rotation at which the spring shaft 29 is rotated in a direction to wind the spring 28 is at a greatly reduced rate relative to the speed of rotation at which the rotatable shaft 22 is operating under normal conditions. Such an arrangement provides several advantages, one of which is that there is less loading on the engine during rewinding of the spring and also that there is less danger of breaking the spring when it is rewound at a relatively low rate of speed. The rewinding means is selectively connected to the shaft 22 by means of clutch means interposed therebetween, which will be more fully described hereafter, so that power may be transmitted from the rotatable shaft 22 to the rewinding means.

Referring more particularly to FIGS. 3 and 4, the rewinding means in the embodiment specifically illustrated is shown as an epicyclic gear train which is mounted on the shaft 29. This arrangement provides an extremely compact turning device and avoids using a plurality of shafts to support the rewinding means as was commonly used in earlier known devices. This gear train comprises a plurality of external and internal gear wheels, and eccentric hubs mounted on shaft 29. This train comprises a first eccentric hub il rotatably mounted on shaft 29 and connected to the clutch means whereby power from shaft 22 may be selectively transmitted to rotate the eccentric hub il on shaft 29. A first internal gear wheel 42 is rotatably mounted on the first eccentric hub 4l and is provided with overlying teeth which mesh with the teeth of a first external gear whee 43 that is rotatably mounted on shaft 29. First external gear wheel t3 is provided with a second eccentric hub 134i on which is rotatably mounted a second external gear wheel 45. A second internal gear wheel dil is rotatably mounted on shaft 29 and is provided with overlying teeth which intermesh with the teeth of second external gear wheel 45. Means are provided to prevent the rst internal gear wheel 42 and the second external gear wheel 45 from rotating about the spring shaft 29 in said one direction and take the form of dogs i5 and 47. The first internal gear wheel 42 is provided with one more tooth than the first external gear wheel 43 and the second external gear wheel 45' is provided with one less tooth than internal gear wheel dit. With this tooth arrangement and holding the rst internal gear wheel 42 and second external gear wheel 4S from rotating about the spring shaft, the direction of rotationof the spring shaft 22 is reversed so that the spring shaft 2i? will be rotated in a direction reverse to the said first direction of rotation and the speed at which it is rotated is reduced. This result is obtained because the clutch parts rotate in the same direction as shaft 22, and drive the hub 41 to rotate in said one direction. This rotation of hub 4l causes the first internal gear wheel d2 to oscillate thereon since it is held against rotation in said one direction. This can be readily seen by reference to FIG. 9. The oscillation of first internal gear wheel 42 will rotate the said first external gear wheel 43 in a direction reverse to the said one direction due to the difference in number of teeth on the respective members and because rst internal gear wheel 42 is held against angular rotation as can be seen in FIG. 8. Rotation of first external gear wheel 43 on shaft 29 causes the second eccentric hub d4 to oscillate the second external gear wheel 45 thereon because second external gear wheel 45 is held against rotation by dog 47 as is shown in FGS. 6 and 7. The oscillation of second external gear wheel 45 will rotate second internal gear wheel 4i? in a direction reverse to said one direction at a reduced rate of rotation. This arrangement, of course, results in rotation of the spring shaft 29 at a greatly reduced angular rotation and in a direction opposite to said first direction at which engine shaft 22 is operating to thereby rewind the spring 28. It is, of course, obvious to those skilled in the art that other methods may be used whereby the direction of rotation between shaft 22 and spring 29 may be reversed and also if desired, that the relative speeds of rotation be greatly reduced. Of course, during rewinding the operating plunger 30 is in the position shown in FIG. 4 whereby the shaft 29 is locked to second pinion 4G.

A manual rewinding means is provided to reset the spring 255 and takes the form of a handle 48 as shown in FIG. l0 which is rotatably mounted upon a circular hub portion 42a of first internal gear wheel 42. This arrangement permits the handle to be moved back and forth Within its limits of travel between the support members 27. A dog 49 is carried on handle t8 in any convenient manner such as by a stud 55, and engages the teeth of second external gear wheel 45. Thus, from FIG. 9 it can be readily seen that operation of the handle in a reciprocal manner will result in dog 49 engaging the teeth of second external gear wheel 45 and rotating it, second internal gear wheel 46' and sha t 29 in a direction reverse to said one direction, thereby rewinding the spring 28.

0f course, the rewinding of the spring 28 is accomplished `through the assistance of the rotational speed reduction provided by second external gear wheel 45 and second internal gear wheel 40 as part of the epicyclic gear train and reduces the effort required to rewind the spring 28 manually. This arrangement permits the turning device to be used with internal combustion engines of a rather large horsepower capacity.

Such an arrangement of the epicyclic gear train provides a very convenient method of reversing the direction of the rotation of the shaft 22 whereby the spring shaft 29 may be rotated inthe proper direction to rewind the spring and also reducing the speed at which it is wound and is one of the important features of the present invention.

Basic Element (3) The clutch means whereby the rewinding means is connected to the shaft 22 is the Basic Element (3) of the present invention and is comprised of

clutch parts

51 and 52 having complementary ratchet-like facings 53, which when engaged, will transmit power between such parts. A rst clutch part 52 is carried on cylindrical housing 37 and a second clutch part 5l is rotatably mounted on spring shaft 29 and is adapted to move to and from first clutch part 52. The clutch parts 5l and 52 are shown in engagement in FIG. 4. In FTG. 3, clutch part 51 is shown disengaged from clutch part 52. It is obvious from the structure provided that when these clutch parts are engaged a driving connection is produced between the rotatable shaft and the rewinding means whereby power may be transmited therebetween.

Basic Element (4) A clutch engaging means is the Basic Element (4) of the present invention and is used to engage and disengage the second clutch part 5l from the first clutch part 52. The clutch engaging means is connected to the spring intermediate its ends and is adapted to engage and disengage the clutch parts in response to movement of the spring as its tension is changed during winding and unwinding whereby said clutch engaging means will engage the clutch parts Sil and 52 as the spring 28 is unwound and will disengage the clutch parts as the spring is wound.

This is an important feature of the preesnt invention since n the rewinding of the spring is controlled by the spring itself and not by Itiming devices which were heretofore required. The clutch engaging means is comprised of a shifting fork 54 which is pivotally mounted on case 26 and is provided with a semicircular portion 55 having guide members 56 mounted thereon which are adapted to engage an annular groove 57 formed in clutch part 51. A shifting fork control rod 55 is `connected to shifting forli 54. The shifting control rod S3, at a position remote from the fork S4, is loosely disposed in a slot 59h in the edge of a disc 59, which disc is pivotally mounted to case 26 by means of stud du. By reference to FlGS. l2 and 13 it will appear that upon rotation of the disc 59 clockwise, the portion of rod 5S within the sm'd slot 5911 will be engaged by the lower side of the slot. The rod being restricted by the pivotal mounting of the fork 5d to a swinging movement about said pivotal mounting in a plane at right angles to said mounting, the portion of said rod in said slot will be moved radially toward the shaft Referring to FlG. 2, it will be seen that this movement will result in counterclockwise movement of the forli 5d and engagement of clutch parts 5l and 52. Rotation of the disc 59 counterclockwise will produce the opposite effect and disengage clutch parts 5l and 52. A pin 6l is secured to spring 25 intermediate its ends and extends out of case 2o through an opening 62 provided therein (see FIGS. 2 and l2). As can best be seen in FIG. 14, pin 6l is received in notch 59a in disc Si), whereas control rod 5? is received in notch 5%. It is evident that the spring will move as it is wound or unwound; therefore, its movement is applied to circular disc 59 to rotate it counterclockwise or clockwise by means of pin dl winch moves with a substantial component radially inwardly or outwardly of the shaft Z9 in response thereto and thereby moves control rod 5d, causing shifting fori( 5d to pivot and move clutch part Si to and from engagement with `clutch part 52. Thus, with the spring fully wound the shifting forli assumes the position shown in FlGS. 2 and 5. As the spring is unwound, the disc 55'* is moved in a clockwise direction as seen in FGS. l2 and 13 to the position shown in FlGS. 4, l2 and 13, which results in shifting forli 5d being moved by control rod Sti counterclocitwise on its pivotal mounting as seen in FlG. 2 to a position whereby clutch part 5i is engaged with clutch part 52. Thus, it can be seen that the movement of the spring ZS as it unwinds and winds causes and is responsible for the action of the shifting fork 5d in moving clutch part 5l into and out of engage- Preferably, pin 6l ist secured to spring ZS adjacent its end that is secured to case Z6. Such an arrangement is advantageous in that the outer extremity of the spring has much greater and faster movement during its initial unwinding than dotthe other positions of the spring, especially those that are secured to spring shaft 29. Thus, only a relatively minor unwinding of the spring need occur to result in the engagement of the clutch part 5l. and 52 with a sudden or snap action, which, of course, results in a very positive engagement of the clutch parts 5l and 52, and th reby prevents chattering about their ratchet faces 53. rEhe spring shaft 29 is unlocked from second internal gear wheel dit when the sp'ing 28 is unwinding and therefore the winding means, comprised of the epicyclic gear train heretofore described, is free to rotate on shaft 29 and therefore may be considered freewheeling so that its inertia is extremely low. Therefore, clutch member Si may be engaged with clutch part 52 to drive the rewinding means even though the turning mechanism is in the process of rotating shaft E?. Vin said one direction to start the engine. Upon the engineV starting, the shaft Z2 is, of course, operated by the power of the engine and results in the pawls 39 being forced away from engagement with the shaft 29, which allows the spring shaft 29 to rotate freely thereby unwinding the spring 2S. When the speed of shaft 29 is only slightly different from the speed of the second internal gear wheel di, of the rewinding means, balls 3d will lock shaft 25 to second internal gear wheel di?, as has heretofore been described. As clutch parts 5l and SZ are engaged under these conditions, the power of shaft 22 will be applied through the rewinding means, which reverses the direcment with clutch part 52 through the mechanism of disc rase i tion of rotation and reduces the speed of rotation, to spring shaft 7&9 so as to rewind spring 23.

As spring 2d is being rewound, the pin 6l carried by the spring is being moved radially inward toward shaft 29, as viewed in PEG. l2, and moves circular disc 59 in a counter clockwise direction, causing shifting rod 58'to move the shifting fork 54 in a direction whereby clutch part 51 is disengaged from clutch part 52. However, during rewinding the movement of the outer extremity of the spring is much slower than it is during unwinding, and, therefore, there is a tendency for the ratchet face 53 of clutch parts 5i and 5?. to chatter as the spring approaches its desired tension. To prevent such undesired chattering of the clutch parts 5l and 52, a snap action means is connected to the clutch means whereby the disengagement of tlic second clutch part 5l from the first clutch part 52 is restrained until a predetermined amount of tension has been stored in spring 28 and applied to the snap action means to overcome the restraining effect, at which time clutch par-t 5l is freed to move rather suddenly and results in a snap action movement of the shifting fork 5ft to disengage clutch part 5l from clutch part 52.

The snap action means can best be seen in FlGS. l2, 13 and 14. The snap action means is provided by one or more balls 63 which were carried in openings 6d in disc 59 engaging recesses in case Z6. A spring plate 65 is provided to ress balls 63 against the case 26 with a pre-selected desired degree of bias that is determined by how tightly stud 6@ is tightened against case 26. The case is provided with one or more recesses 66 (shown in FlG. l2 wherein plate 65 and disc 553 are broken away to expose same) in its surface wherein balls 63 may be received when the shifting fork 54 has engaged clutch parts 5l and d?, and the disc 59 is moved to a counter clockwise position by pin 6l as the spring is unwound. lt is evident that this is a simple detent means which will result in disc 59 being restrained from moving in a clockwise direction due toV engagement of ball 63 with recess 66 until the tension of the spring 28 as it is rewound increases and can overcome the restraining effect created by the biasing of ball 63 into recess 66 by spring plate 65. Upon such occurrence, the disc 59 is free to move with great suddenness or with a snap action, thereby allowing shifting forli Sd to disengage clutch part 5l from clutch part 52 with a snap action.

@ther recesses may be provided in cover 2e whereby the engagement of the clutch parts may be effected with a snap action as the spring is unwound where the pin di is connected to the spring Z3 at positions intermediate its ends and other than adiacent its end secured to case 26. The snap action mechanism may talee other forms than that specicaliy illustrated herein, such that a snap action movement is produced in either engagement or disengagenent of the clutch parts, or in both functions.

The turning device operates in the following manner. With the spring unwound and the engine 2l inoperative, theV handle this rocked to rotate second external gear wheel d5, second internal gear wheel dil and spring shaft 2S to rewind the spring 28 to any desired initial tension.

With the spring rewound, plunger 3i? is depressed and released whereon shaft 2g is freed to be rotated very quiclily by spring 2S. Rotation of shaft Z9 is transmitted to engine shaft 22 and usually results in engine 2l being started. Should the engine fail toA start, the spring may be readily rewound by means of handle 48. Once the engine has started, power is transmitted from shaft 22 to the ret/vinding means and the plunger 36 returns to its original position which results in shaft 29 being rotated in a proper direction to rewind the spring. Upon the spring being rewound, the clutch means are disengaged with a snap action and the turning device is ready for the next cycle of starting engine 2l. The rewinding of the spring is completely automatic when the engine starts.

The turning device of the present invention can be readily installed on existing devices as is apparent from the drawings and the description herein.

Thus, there has been provided herein a novel turning device for a rotatable shaft in which the spring is wound and unwound from the same end and which utilizes a single spring shaft extending from only one side of the case which houses the spring. The rewinding means for restoring the spring to a wound condition is simple yet compact and eicient. Further, the functioning of the rewinding means is controlled by the movement of the spring as its tension is changed during winding and unwinding, thus completely dispensing with any complex timing device such as heretofore required to control the rewinding of the spring. If desired, snap action means are provided to prevent the clutch means used to transmit power to the rewinding means from being damaged through a lack of positive engagement and disengagement.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the device.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed l. A turning device for a rotatable shaft comprising, an anchor with respect to which said shaft is rotatable, a spring shaft rotatably mounted with respect to said anchor, a spring positioned and extending about the spring shaft having one end attached to the spring shaft and the other end secured to the anchor, the spring when wound adapted to rotate the spring shaft in one direction, means by which a driving connection is made between the spring shaft and such rotatable shaft for rotating the last-mentioned shaft in said one direction, rewinding means connected to the spring shaft for rotating the spring shaft in a direction reverse to said one direction to wind said spring, clutch means interposedbetween said rewinding means and the rotatable shaft, said clutch means when engaged providing a drive connection between said rewinding means and the rotatable shaft, and clutch engaging means connected to the spring intermediate its ends and adapted to engage and disengage said clutch means in response to movement of the spring as its tension is changed during winding and unwinding whereby said clutch engaging means engages said clutch means as the spring is unwound and disengages said clutch means as the spring is wound.

2. A turning device as in claim 1, wherein said clutch engaging means is connected to the spring adjacent the end of the spring secured -to the case.

3. A turning device for a rotatable shaft comprising an anchor with respect to which said shaft is rotatable, a spring shaft rotatably mounted with respect to said anchor, a spring positioned and extending about the spring shaft having one end attached to the spring shaft and the other end secured to the anchor, the spring when wound adapated to rotate the spring shaft in one direction, means by which a driving connection is made between the spring shaft and such rotatable shaft for rotating the lastmentioned shaft in said one direction, rewinding means connected to the spring shaft for rotating the spring shaft in a direction reverse to said one direction to wind said spring, clutch means interposed between said rewinding means and said rotatable shaft, said clutch means when engaged providing a drive connection between said rewinding means and therotatable shaft, clutch engaging means connected to the spring intermediate its ends and adapted to engage and disengage said clutch means in response to movement of the spring as its tension is changed during winding and unwinding, and a snap action means connected to the clutch means for restraining disengagement of said clutch means until its restraining action is overcome by spring tension whereby said clutch engaging means disengages said clutch means with a snap action upon the tension of the spring increasing sufficiently to overcome the restraining action of said snap action means as the spring is wound.

4. A turning device as in claim 3, wherein said clutch engaging means is connected to the spring adjacent the end of the spring secured to the case.

5. A turning device as in claim 3 wherein said snap action means comprises a detent means to restrain engagement of the clutch engaging means until its restraining action is overcome by a predetermined increase in tension of the spring whereby the detent means releases thereby permitting engagement of the clutch means with a snap action.

6. A turning device for a rotatable shaft comprising, a case stationary with respect to said rotatable shaft, a spring shaft rotatably mounted in the case and extending therefrom, a spring positioned within the case and extending about the spring shaft having one end attached to the spring shaft and the other end secured -to the case, the spring when wound adapted to rotate the spring shaft in one direction, means by which a driving connection is made between the spring shaft and such rotatable shaft for rotating the last-mentioned shaft in said one direction, rewinding means connected to the spring shaft for rotating the spring shaft in a direction reverse to said one direction to Wind said spring, clutch means interposed between said rewinding means and the rotatable shaft, said clutch means when engaged providing a drive connection between said rewinding means and the rotatable shaft, clutch engaging means connected to the spring intermediate its ends and adapted to engage and disengage said clutch means in response to movement of the sping as its tension is changed during winding and unwinding whereby said clutch engaging means engages said clutch means as the spring is unwound and disengages said clutch means as the spring is wound, and a snap action means connected to the clutch means for restraining the engagement and disengagement of the clutch means until such restraining action is overcome by spring tension whereby said clutch engaging means engages the clutch means with a snap action upon the tension of the spring decreasing suiciently -to overcome such restraining effect as the spring is unwound and disengages the clutch means with a snap action upon the tension of the spring increasing sufficiently to overcome the restraining effect of the snap action means as the spring is Wound.

7. A turning device as in claim 6 wherein said clutch engaging means is connected to the spring adjacent the end of the spring secured to the case.

8. A turning device as in claim 6 wherein said snap action means comprises a detent means to restrain engagement of the clutch engaging means until its restraining action is overcome by a predetermined increase in tension of the spring whereby the detent means releases thereby permitting engagement of the clutch means with a snap action.

9. A turning device for a rotatable shaft comprising a case stationary with respect to said rotatable shaft, a spring shaft rotatably mounted in the case and extending therefrom, a spring positioned within the case and extending about the spring shaft having one end attached to the spring shaft and the other end secured to the case, the spring when Wound adapted to rotate the spring shaft in one direction, means by which a driving connection is made between the spring shaft and such rotatable shaft afi/rasoi for rotating the last-mentioned shaft in said one direction, rewinding means connected to the spring shaft for rotating the spring shaft in a direction reverse to said one direction to Wind said spring, clutch means interposed between said rewinding means and said rotatable shaft when engaged to transmit power from the rotatable shaft to the rewinding means, said clutch means comprising a first clutch part carried by the rotatabie shaft, and a second clutch part rotatably mounted on said spring shaft, said second clutch part being slidably mounted on said spring shaft for movement to and from said first clutch part; clutch engaging means comprising a shifting fork pivotally mounted on the case and adapted to move said second clutch part, and said shifting fork connected .to the spring adjacent the end of the spring secured to the case and adapted to move said second clutch part into and out of engagement with said first clutch part in response to movement of the spring as its tension is changed during winding and unwinding, a snap action means connected to the clutch means for restraining movement of said second clutch part out of engagement with said first clutch part until its restraining action is overcome by spring tension, whereby the shifting fork moves the second clutch part into engagement with the first ciutch part upon the tension of the spring decreasing as the spring is unwound and moves the second clutch part out of engagement with the first 'clutch part with a snap action upon the tension of the spring increasing sufficiently to overcome the restraining action of said snap action means upon the spring being wound.

10. A turning device as in claim 9 wherein said re- Winding means is an epicyclic gear train which comprises, a first eccentric hub carried by said second clutch part, a rst pinion rotatably mounted on said ecentric hub, a first wheel rotatably mounted on the spring shaft and adjacent to said first pinion and having teeth intermeshed therewith, said first wheel having at least one tooth less than said first pinion, a second eccentric hub carried by said first wheel, a second wheel rotatably mounted on said eccentric hub of said first Wheel, a second pinion carried by said spring shaft adjacent to said second wheel and teeth intermeshed therewith, said second pinion having at least one tooth more than said second wheel, means to prevent the first pinion and second wheel from rotating about the spring shaft, rotation of the second clutch part in said one direction causing said first pinion to oscillate on the first eccentric hub and thereby said first pinion driving said first wheel in a reverse direction to said one direction at a reduced angular rotation, rotation of said first wheel causing said second Wheel to oscillate on the second eccentric hub and thereby said second wheel driving said second pinion at a reduced angular rotation to rotate the spring shaft and wind the spring.

11. A turning device as in claim 9 wherein said snap action means comprising, a movable member connected to said clutch means and adapted to be moved to a first position when the second clutch part is disengaged from the first clutch part and to a second position when the clutch parts are engaged, a stationary member that is stationary with respect to said movable member, detent means carried by one of the members and detent receiving means carried by the other of said members, said detent and detent receiving means engaging when the movable member is in said second position and thereby restraining movement of said movable member to the first position until the tension of the spring increases sufiiciently upon the spring being wound to overcome such restraining action whereby said movable member is moved from the second position to the first posi-tion with a snap action.

l2. A turning device for a rotatable shaft comprising an anchor with respect to which such shaft is rotatable, a spring shaft rotatably mounted with respect to said anchor, a spring having one part secured to the spring shaft and another to the anchor, the spring when wound adapted to rotate the spring shaft in one direction, means by which a driving connection is made between the spring shaft and such rotatable shaft for rotating the lastmentioned shaft in said one direction, rewinding means connected to the spring shaft for rotating the spring shaft in a direction reverse to said one direction to wind said spring, clutch means interposed between said rewinding means and the rotatable shaft, said clutch means when engaged providing a driving connection between said rewinding means and the rotatable shaft, clutch engaging means connected to said clutch and positioned to be acted upon by said spring in proportion to the degree of winding thereof for engaging and disengaging the clutch when said spring' has been wound to a predetermined degree, and snap action means connected to the clutch means for resisting disengagement thereof until its resisting action is overcome by the increasing tension of said spring as it becomes more fully wound.

References Cited in the file of this patent UNITED STATES PATENTS 2,642,841 Harmon June 2, 1936 2,804,173 De Millar Aug. 27, 1957 2,919,770 Roggendorff Ian. 5, 1960 2,987,057 Kopp June 6, 1961 3,010,443 Lyvers Nov. 28, 1961 3,032,024 Furlong May 1, 1962

Claims

1. A TURNING DEVICE FOR A ROTATABLE SHAFT COMPRISING, AN ANCHOR WITH RESPECT TO WHICH SAID SHAFT IS ROTATABLE, A SPRING SHAFT ROTATABLY MOUNTED WITH RESPECT TO SAID ANCHOR, A SPRING POSITIONED AND EXTENDING ABOUT THE SPRING SHAFT HAVING ONE END ATTACHED TO THE SPRING SHAFT AND THE OTHER END SECURED TO THE ANCHOR, THE SPRING WHEN WOUND ADAPTED TO ROTATE THE SPRING SHAFT IN ONE DIRECTION, MEANS BY WHICH A DRIVING CONNECTION IS MADE BETWEEN THE SPRING SHAFT AND SUCH ROTATABLE SHAFT FOR ROTATING THE LAST-MENTIONED SHAFT IN SAID ONE DIRECTION, REWINDING MEANS CONNECTED TO THE SPRING SHAFT FOR ROTATING THE SPRING SHAFT IN A DIRECTION REVERSE TO SAID ONE DIRECTION TO WIND SAID SPRING, CLUTCH MEANS INTERPOSED BETWEEN SAID REWINDING MEANS AND THE ROTATABLE SHAFT, SAID CLUTCH MEANS WHEN ENGAGED PROVIDING A DRIVE CONNECTION BETWEEN SAID REWINDING MEANS AND THE ROTATABLE SHAFT, AND CLUTCH ENGAGING MEANS CONNECTED TO THE SPRING INTERMEDIATE ITS ENDS AND ADAPTED TO ENGAGE AND DISENGAGE SAID CLUTCH MEANS IN RESPONSE TO MOVEMENT OF THE SPRING AS ITS TENSION IS CHANGED DURING WINDING AND UNWINDING WHEREBY SAID CLUTCH ENGAGING MEANS ENGAGES SAID CLUTCH MEANS AS THE SPRING IS UNWOUND AND DISENGAGES SAID CLUTCH MEANS AS THE SPRING IS WOUND.