US2622701A - Engine starter - Google Patents

Description

Dec. 23, 1952 B. H. KELLOGG ET AL ENGINE STARTER 2 SHEETS-SHEET 1 Filed April 10, 1950 ow mv mm INVENTORS BRUCE H. KELL066 D M COL/N R006 PATENT AGEN H m-H..P

n Mn 6 n mm mv mm mm V mm 1952 B. H. KELLOGG EIAL 01 ENGINE STARTER Filed April 10, 1950 2 SHEETS-SHEET 2 INVENTORS BRUfiE H. KELLOGG BY KJ FKZZZZLJ/ PATENT AGE Patented Dec. 23, 1952 ENGINE STARTER Bruce H. Kellogg, Los Gates, and Golin D Mur- (loch, SanJose', Calif.; Helen Johnson Kellogg administratrix of said Bruce H. Kellogg, de-

ceased Application April 1-0, 1950, Serial No. 154,986

2 Claims.

Our invention relates to engine starters and is directed more particularly tov devices for facilitating the hand crankingv of small internal combustion engines such as, for example, those. employed in model airplanes.

The starting of small internal combustion engines is usually accomplished by the operator using his fingers to turn the propeller as rapidly as possible through part oi. an engine revolution with a quick flipping action. However, the normal operating speeds of such engines are so high relative to the cranking speeds. obtainable by direct n'ianual means that manual cranking is not conducive to reliable starting As an additional disadvantage manual cranking as described above has a tendency to place unwarranted loads on the engine supporting means. Moreover, should the engine start as a. result of the described manipulation the following. propeller blade may strike the operators finger and inflict a painful injury before he has the opportunity to withdraw his finger from the plane of rotation of the propeller.

An object oi the present invention is to provide a safe, simple and dependable hand starter for small internal combustion engines.

Another object of. the invention is to provide a starter for small internal. combustion engines which can be operated without manual contact with the moving parts of the engine.

Yet another object of the invention is to'provide an improved model engine starter which eliminates the imposing. of stresses other than starting torque on the engine during starting Furthermore, it is an object. of our invention to provide an engine starter of the type referred to that is ineffective to stall the engine once it has started, even though it may remain coupled to the engine.

Still another object. of the invention is to provide an engine starter, of the type referred to, that may remain coupled to the: engine: after the has started operation, without danger to the operators hand or the implement itselt.

These other objectsv of our invention will be apparent from the following description of the accompanying drawings which illustrate certain preferred embodiments thereof and wherein Figure l is a fragmentary longitudinal section through a model engine starter embodying our invention;

Figure 2 is a perspective view of some of the components forming part of the device illustrated in Figure 1;

Figure 3 is a elevation of one of the components illustn ted in Figure 2;

Fig its 4, 5, 6A and. 8B show coupling means employed to apply the rotary power of the implement illustrated in Figure r to the crank shaft of engines;

Figure 7 is a fragmentary elevation of the engine starter shown in Figure 1 illustrating the preferred method. of gripping and manipulating said device when applying it to the crank shaft of an engine.

Referring first to Figure 1, the implement of our invention comprises a tubular housing 29 within which is coaxially arranged a longitu clinal shaft 2! that is suitably journalled in a ball bearing 22-. Coiled around said shaft is a spring 23 in which the power required for crank" ing an engine may be stored and which is shown to have a right hand. helix. The right endv of said spring is bent to form a tang 26, which is fitted into a longitudinal slot 25 provided in an annular adapter 26 that is pinned to the tubular housing 2*] as shown at 2?. Said adapter 26 may have a tubular extension 23 of somewhat reduced diameter that fits into the interior of, and sup ports the spring 23 to maintain said spring in a properly centered position coaxial with the tubular housing 20. The left end of spring 23 is likewise formed into. a tang, shown at 29, which is received. in a longitudinal slot 36 provided in another annular adapter element 3i which is of such diameter as to be freely rotatable within the tubular housing 23 and which is firmly mounted upon the. aforementioned shaft 2 l. Said adapter element 3! may also be provided with a centering extension 32 that extends into the interior of and supports the helical spring 23 at the left end thereof.

In accordance with our invention means are provided that may be engaged with the shaft 2! for the purpose of turning said shaft in a manner that will wind the spring 23. For this purpose the right hand end of shaft N is designed to be of angular cross-sectional contour to form a key, such as the hexagonal key 33, shown in Figure 1, and a bushing 34 located within and pinned to the tubular housing 20 near the right end thereof is arranged to slideably support another shaft 3% in axial alignment with the previously described shaft 23. The left end of said shaft 35 is extended to form a head "it within which is formed a socket 37 of a shape and size adapted to receive and engage the key 33. The right hand end of the shaft 35 is formed into a threaded tenon 33 that engages a correspondingly threaded bore 38 provided in the center of a cap it which is arranged to telescope over the open right hand end of the tubular housing 25!. Said cap 49 may be provided with a cross piece 4! that extends diametrically through a suitable transverse bore provided in said cap and which may be held in position by the threaded tenon 38, as shown An expansion spring 53 coiled about the shaft 35 is interposed between the right face of the aforementioned stationary bushing at and the inner end wall of the cap and urges said cap and,

3 hence, said shaft 35 into an extreme right position as determined by abutment of head 36 against the left face of the stationary bushing 34; in said extreme right position of the shaft 35 the head 35 is axially spaced from the key 33 at the right hand end of the main shaft 23. Thus, ordinarily the shafts 23 and 35 are disengaged from one another, but when the operator presses the cap 48 against the tubular housing 20, as he Will normally do when gripping the tubular housing 26 with one hand and said cap 40 with the other hand, the shaft 35 is pushed deeper into the housing 26 so that its socket 31 engages the key 33 whereupon the shafts 2| and 35 are operatively connected. Thereafter, by turning the cap in clockwise direction the spring 23 may effectively be wound. On the other hand, whenever the operator releases the cap 45, the spring 43 restores said cap to its rightmost position and in this manner disengages the winding shaft 35 from the main shaft 2|. In the preferred embodiment of the invention, as illustrated in the accompanying drawings, where the power storage spring has a right hand helix and is wound by turning the shafts 2| and 35 in clockwise direction, as pointed out above, the restore spring 43 is shown as having a left handhelix to cause the ends of said spring to trail on the right surface of the bushing 34 and the inner surface of the cap 40,

respectively, whenever the cap 40 is turned to wind the power spring 23. This renders the winding operation smooth, since it prevents the ends of the restore spring from catching on the adjacent surfaces whenever the cap is turned in clockwise direction.

Means are provided in accordance with the invention which are automatically effective to retain the spring 23 in wound-up condition whenever the operator releases the cap 45 and which may yet be readily unlatched to fully release the power stored in said spring 23 whenever the implement is applied to an engine for the purpose of cranking the same. To this end a sleeve 45 is arranged coaxially around the front end of the main shaft 2|. Said sleeve is of somewhat smaller diameter than the interior of the tubular housing 20 and has a forwardly projecting portion 46 of reduced diameter that is journalled in a ball bearing 4! which is provided within the housing 23 near its forward end. Notches 49 are cut into the shoulder over which the sleeve 45 is reduced to the diameter of its forward extension 46 (Figures 2 and 3) and said notches may be engaged by a stud 52 that extends through a longitudinal slot 53 provided in the tubular housing 20. Said stud 52 is mounted in the wall of a bullet-shaped open-ended cap 54 which is slipped over and slideably engages the forward end of said tubular housing 2 0. Whenever the shaft 2 is turned by appropriate manipulation of cap 40 to Wind the spring 23 with a view of storing up the power required for cranking an engine, the cap 54 should first be moved to the right of the position shown in Figure 1 so that the stud 52 may engage one of the notches 49 in the sleeve 45 and in this manner lock said sleeve against rotary movement. Interposed between the sleeve 45 and the forward end of the shaft 2| are means that permit said shaft to turn freely in clockwise direction in which it winds the spring 23, yet are automatically effective to lock said shaft to said sleeve 45 whenever the shaft tends to move in counterclockwise direction which would unwind the spring 23, so that said shaft is unable to follow the urge of spring 23, whenever the stud 52 engages one of the notches 49.

For this purpose a helical spring 55 coiled around the forward end of the main shaft 2| in a direction opposite to the power storage spring 23 is arranged within the interior of the aforementioned sleeve 45. The left end of said spring 55 is free and may glide along the inner surface formed by the shoulder 50 of said sleeve 45 while its right hand end is bent to form a radially extending tang 56 (Figure 2) that is anchored in a radially extending aperture 51 provided in a forwardly directed tubular extension 58 of the previously described adapter element 3|. Said extension 58 is of a reduced diameter as compared with the main body of the adapter element 3| to fit loosely into the open end of the sleeve 45, and is, in turn, reduced in diameter at the point of aperture 51 to form a centering projection 59 that fits into and supports the right end of the spring 55. The shoulder 60 formed by said last mentioned reduction in the diameter of the adapter 3| is preferably designed to follow the course of a convolution of spring 55, as best shown in Figure 2, so as to provide perfect abutment for the right end of said spring. Said spring 55 is arranged to have a slight interference fit with the bore 45a of sleeve 45, when there is no torque applied to said spring tending to rotate it within the sleeve 45.

Whenever the main shaft 2| is turned in clockwise direction (as viewed from the right or rear end of the implement) to wind the power storage spring 23, said shaft applies a winding torque to the right end of the spring 55 which causes said spring to contract in diameter so that it will freely rotate within the bore 45a. Thus, the shaft 2| may freely be turned in clockwise direction to wind the power storage spring 23, though the sleeve 45 may securely be locked against rotary movement by engagement of stud 52 in any of the notches 49. However, whenever the operator releases the cap 40 to change his grip or to move the cross handle 4| to a new position for more convenient manipulation thereof, and the power storage spring 23 endeavors to unwind itself and turn the main shaft 2| in counterclockwise direction, the counterclockwise torque applied to the right end of the spring 55 by the edge 60a in the convoluted shoulder 60 of the adapter 3| causes said spring 55 to expand in diameter so that its convolutions press against and clutch the interior wall of the sleeve 45. This establishes positive operative connection between the main shaft 2| and the sleeve 45 and since the sleeve 45 is positively restrained from rotary movement by the stud 52, the main shaft 2| is unable to follow the unwinding effort of the power storage spring 23 so that the power stored in said spring by previous manipulation of the cap 40 is retained even though the operator may have released the handle 4|. However, when the stud 52 is withdrawn from whatever notch 49 it may engage at the moment, by pushing the cap 54 in forward direction, the power storage spring 23 is free to unwind itself and will rapidly turn the shaft 2|, the adapter element 3|, the clutching spring 55 and the clutch sleeve 45 in counterclockwise direction until it has released the power previously stored therein.

To apply the rapid rotary motion of the clutch sleeve 45 to an engine for the purpose of cranking said engine, a chucking element 65 may be suitably secured to the front end of said clutch sleeve, such as by means of a screw bolt 66, as

5. shown in Figure 1. said chucking element may be of socket shape with suitable notches 61a and 61b arranged in its outer edge 68, as shown in Figure 4., which notches are adapted to receive corresponding lugs or blocks 69a and 6% provided along the inner cylindrical surface of an adapter washer 10 that may be secured to the crank shaft of an engine by keying, clamping, splining or the like. The inner diameter of said adapter washer is preferably only slightly larger than the outer diameter of the chucking element so as to act as a guide which insures concentrical alignment of said chucking element with the engine shaft whenever the notches of the former are brought into engagement with the blocks of the adapter washer 10.

In the event that the implement of our invention is to be employed for cranking the engines of model airplanes which frequently have crank shafts that end in stream-lined spinners, such as shown at H in Figure 5, a special adapter element may have to be fitted into the described chucking element 65 to effectively apply the rotary motion of the starter to said spinners. Having specific reference to Figure 5, said adapter element may have the form of a cup 12 made of elastic material such as rubber, which possesses a stem-shaped pilot member 13 that fits snugly into the hollow interior of the chucking element 65 (Figure 4) and which is provided with outwardly extending lugs 14'that fit into the notches 61a and 67b in the outer edge 68 of said chucking element 65. Near its outer edge the inner surface of said cup 72 may be provided with numerous ribs 15 the ridges of which are arranged to converge toward the bottom of the cup, as shown, and which are brought into contact with the surface of the spinner H and firmly grip said spinner whenever the chucking element 65 is turned.

Still another manner in which operative connection may be established between the chucking element of our implement and the crank shaft of an engine is illustrated in Figures 6A and 6B. In the embodiments illustrated in said figures the head I! of the bolt 66, which secures the chucking element to the tubular extension 46 of the clutch sleeve 45, is designed to form a depression 18 within which is received the inner end of a key bar 1'9 that may be of hexagonal cross-sectional contour, as shown. Said key bar is firmly held within the interior of the chucking element 65 by forcing a tubular sleeve 80 of resilient material, such as rubber, into the space between the key andthe inner surface of the chucking ele ment. The projecting end of said key may be brought into engagement with a socket 8! of corresponding cross-sectional contour that may be secured to the end of an engine crank shaft 82. In arrangements of this type metal to metal contact between the chucking element 65 and the adapter socket 8| may easily be precluded by extending the spacer sleeve 80 outwardly beyond the outer edge of the chucking element, as shown at 83 in both Figures 6A and GB. To maintain substantially coaxial alignment between the adapter socket 8| and the key bar 19 when disengaging said bar from the rotating crank shaft after the engine has been started, the socket dl may have a smooth cylindrical surface near its outer end, as shown at 84 in Figure 6A or the outer end of the key [9 may be formed in the manner of a smooth cylindrical projection, as shown at 85 in Figure 6B. 7

In practical performance the operator shifts the front cap 54 of the described implement to the right, as viewedin Figure's' l and- 7, to-engagethe' stud 52 inone of the notches 49 provided in the shoulder 50 of the clutch sleeve 45. To render the described shifting operation smooth and also to exclude moisture and other foreign matter from the interior of the described implement, felt liners 9| and 92' may be interposed between cap 54 and housing 20 and chucking element 65, respectively, as shown in'Figure 1. With the clutch sleeve 45 locked against rotary motion by stud 52 the operator grips the cross piece 4| of the rear cap 40 with his right hand while holding the body 20 of the implement with his left hand and pushes the named elements together to cause engagement ofkey 33 in socket 31. Having thus established operative connection between the shafts 35 and 2i, he turns the cap in clockwise direction, as viewed from the rear of the implement, to wind the power storage spring 23. Clockwise rotation of shaft 2| is effective to exert a winding torque upon the clutching spring causing said right end of the clutching spring 55 which ex-' pands in consequence thereof and clutches the inner surface of the sleeve 45; and since the latter is locked against rotary movement by the stud 52, as previously pointed out, the adapter 3| is unable to yield to the unwinding effort of the power storage spring 23 so that said spring is positively retained in wound condition, After the power storage spring 23 has been fully wound in the described manner the implement is ready for use. The operator may now grip the implement with his right hand in the manner illustrated in Figure"! and bring its chucking element into proper engagement with a suitable adapter washer secured to the crank shaft of an engine as previously explained in connection with Figures 4, 5, 6A and 6B. Thereupon he presses with his thumb against the edge of cap 54, as shown in Figure 7, to shift said cap forwardly relative to the tubular housing 20. In this manner the stud 52 is withdrawn from whatever notch 49 in clutch sleeve 45 it engaged at the time; and with the clutch sleeve thus released for rotary motion the power storage spring 23 is free to unwind itself and, through the expanded coupling spring 55, turns the sleeve 45 and the chucking element 65 rapidly in counterclockwise direction until the available energy in spring 23 is sufficiently spent so that rotation ceases. Since the restore spring 43' at the rear end of the implement disengaged the winding shaft 35 from the shaft 2| directly after the operator released the cap 4! the described rotation of the adapter 3! remains withouteffect upon the cap 40 so that there is no possibility for the operator to come to harm by blows from the ends of the cross-piece 4i.

To facilitate disengagement of the stud 52 from the notches 49 and reduce the physical effort on the operators part to release the power stored in spring 23, the surfaces 48a of the notches 49 that are normally contacted by the stud 52 are preferably inclined at an angle which tends to thrust the stud out of the notches, as shown in Figures 2 and 3. In said figures the clockwise edges of said notches diverge in outward direction from the opposite edges thereof and thus facilitates disengagement of the stud 52 from said notches whenever counterclockwise torque is applied to the sleeve 45.

Whenever the engine starts operating under its own power as a result of the described application of our engine starter, the operator simply withdraws the implement in axial direction from the crank shaft of the engine without exposing his fingers at any time to the danger of being struck by moving parts of the engine, such as the propeller blades of model airplane engines. However, when an engine starts operating under its own power, some time will usually elapse before the implement is fully disengaged from the rotating crank shaft. The engine may, therefore, rotate the chucking element 65 beyond the point at which the power spring 23 is completely unwound. In the case of small engines this may cause the engine to stall since small engines do not, as a rule, develop sufficient power to wind the spring 23 backwards. On the other hand, in the case of larger engines that develop sufficient power to wind the spring 23 backwards, such an occurrence may not only harm the spring by winding it in the reverse direction but may cause said spring to grip and turn the tube which would jolt the operators hand. The implement of our invention is of such construction that it may remain coupled to an operating engine without danger of stalling the engine and without doing harm to the power storage spring or the operators hand.

Having reference t Figure 1, whenever an operating engine has turned the chucking element 65 and the adapter 3| to a point where the power storage spring 23 is completely unwound and further rotation of said adapter 3| would wind said spring in the reverse direction, the resistance offered by said spring 23 to further rotation of the adapter 31 exerts a clockwise torque upon the right end of the clutching spring 55 as said spring is rotated in counterclockwise direction with the clutch sleeve 45 by operation of the started engine. This torque tends to wind up the spring 55 and thus reduces its outside diameter so that the driving connection established by said spring in expanded condition between the clutch sleeve 45 and the main shaft 2| is abolished. Hence, the chucking element 65 and the clutch sleeve 45 may continue to rotate in counter-clockwise direction for an indefinite number of revolutions while exerting only a slight frictionally developed torque upon the power storage spring 23 through the clutch spring 55 and the adapter 3|, which torque is neither harmful to said spring nor dangerous t the operators hand.

While we have explained our invention with the aid of an exemplary embodiment thereof, it will be understood that we do not wish to be limited to the constructional details illustrated or described which may be departed from without departing from the scope and spirit of our invention. Thus, While we have shown both, the clutching spring 55 and the inner bore of the sleeve 45 as of cylindrical shape, the slight interference fit between said elements as required in accordance with our invention may be established by making the bore of sleeve 45 of cylindrioal shape while making the spring 55 of hell shape, or vice versa by retaining the cylindrical shape of the spring while making the bore of 8. the sleeve of conical shape. In fact, it will be readily apparent to those skilled in the art that over-running clutches other than the one constituted by the above described elements 3|, 55 and 45 may be employed in the instrument of our invention without departing from the scope and spirit thereof. Also, while in the described embodiment of our invention the helices of the springs 23, 43 and 55 have been chosen with a view of providing an instrument that will start an engine which operates in counterclockwise direction it will be obvious to those skilled in the art that an implement adapted to start an engine which operates in clockwise direction may be provided by the simple expedient of reversing the direction of the helix of said springs.

We claim:

1. An engine starter for cranking miniature engines, such as model airplane engines. comprising a tubular housing having a longitudinal slot provided near its front end, a shaft rotatably mounted and extending concentrically within said housing, a power storage spring coiled around said shaft and having its ends supported from said shaft and said housing, respectively, a chucking element rotatably mounted in coaxial alignment with said shaft at the front end thereof, a clutch sleeve rigidly connected to said chucking element and arranged around the front end of said shaft, said sleeve having a plurality of forwardly opening notches provided circumferentially around its outer surface, a clutching spring coiled around the front end of said shaft and having a slight interference fit with said sleeve, one end of said clutching spring being connected to said shaft in a manner effective to exert an unwinding torque upon said clutching spring whenever said shaft is turned in a direction unwinding said power storage spring, and t exert a winding torque upon said clutching spring whenever said shaft is turned in a direction effective to Wind said power storage spring, a cap slideably engaging the front end of said housing, a stud mounted in said cap and extending through said slot, said cap being movable from a first position wherein said stud engages one of said notches to a second position wherein said stud stands clear of said notches, and manually operable means for turning said shaft arranged at the rear end of said shaft.

2. An implement according to claim 1 wherein said notches have outwardly diverging edges to facilitate disengagement of said stud when said cap is moved from said first to said second position BRUCE H. KELLOGG. COLIN D. MURDOCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,337,113 Bond Apr. 13, 1920 1,620,998 Clark Mar. 15, 1927 1,646,427 Skidmore Oct. 25, 1927 1,936,554 Lansing Nov. 21, 1933 2,043,695 Brownlee June 9, 1936 2,146,764 Ricefleld Feb. 14, 1939 2,385,963 Beard Oct. 2, 1945 2,419,045 Whittaker Apr. 15, 1947 2,461,784 Streed Feb. 15, 1949 2,516,269 Starkey July 25, 1950

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