US3565050A

US3565050A - Recoil type of internal combustion engine starter

Info

Publication number: US3565050A
Application number: US825240A
Authority: US
Inventors: Paul J Clymer; Neill C Woelffer
Original assignee: Jacobsen Manufacturing Co
Current assignee: Jacobsen Manufacturing Co
Priority date: 1969-05-16
Filing date: 1969-05-16
Publication date: 1971-02-23
Anticipated expiration: 1988-02-23

Abstract

A recoil type of internal combustion engine starter having a rope-pull type of pulley and a recoil spring. A pawl is pivotally mounted on the pulley to extend therefrom and engage a member on the engine shaft for starting the engine. A lever is movable relative to the pulley and engages the pawl to extend the pawl from the pulley in the starting action, and the lever permits the pawl to be retracted, irrespective of the position of the lever. The lever also serves to hold the pawl in the retracted position so that it will not become inadvertently engaged with the member on the engine shaft.

Description

PATENTEDEBNIQH 3.5651350 INVENTORS: NE/LL C. WOELFFER PAUL J. CLVMER United States Patent Inventors Appl. No. Filed Patented Assignee RECOIL TYPE OF INTERNAL COMBUSTION ENGINE STARTER 16 Claims, 7 Drawing Figs.

U.S. Cl. 123/185 Int. Cl. F02n l/00 Field of Search 123/185 (O1), 185 (B), 185 (8-1), 185 (C) Primary ExaminerMark M. Newman Assistant Examiner-Ronald B. Cox AttorneyArthur J. I-Iansmann ABSTRACT: A recoil type of internal combustion engine starter having a rope-pull type of pulley and a recoil spring. A pawl is pivotally mounted on the pulley to extend therefrom and engage a member on the engine shaft for starting the engine. A lever is movable relative to the pulley and engages the pawl to extendthe pawl from the pulley in the starting action, and the lever permits the pawl to be retracted, irrespective of the position of the lever. The lever also serves to hold the pawl in the retracted position so that it will not become inadvertently engaged with the member on the engine shaft.

. RECOIL TYPE OF INTERNAL COMBUSTION ENGINE STARTER This in starting small gasoline engines used in powering lawn mowers, garden tractors, snow throwers, and like powered tools. r

BACKGROUND OF THE INVENTION Recoil types of engine starters are known in many different forms. These starters use ropes trained on pulleys for rotating the engine shaft in the starting process. Also, recoil springs are connected to the pulleys for rewinding the rope when the operator has released the rope after giving it a starting pull. Further, the prior art starters utilize pawls or the like for drivingly connecting the pulley to the engine shaft through intervening means. These pawls can pivot away from the pulley and into engagement with the shaft means, and they again then retract into the pulley when the starting pull is completed or when the engine is running. One such prior art starter is shown in U.S. Pat. No. 3,366,099. That patent shows a pulley with a pivotal pawl, and it shows a lever or like member for controlling the-pivot of the pawl to move the pawl into and out of engagement with the means on the engine shaft. However, the pawl is under full control of the lever, since one position of the lever causes the pawl to be retracted onto the pulley, and another position of the lever causes the pawl to beextended from the pulley. That is, in either position of the lever, the

pawl occupies its corresponding position. This is somewhat of a problem, since, when the engine is running, it is desired that the pawl be in the retracted position. However, if the lever were in the wrong position, the pawl would be extended, rather than retracted, and then starter orengine damage could result. Further, the prior art starters utilizing pawls have not been effective in retaining the pawl in the retracted position, and, in fact, they have not always been effective in extending the pawl each time the starter rope is pulled. These aforementioned problems are not necessarily related to the said patent, but they are and can be a problem relative to other starters using pawls.

It is a general object of the presentinvention to improve upon starters of the type mentioned. More specifically, it is the object of this invention to provide a pawl-type starter wherein the pawl is retained in its retracted position, even though the operating conditions and the engine vibration may tend to move the pawl to its extended position from the pulley. Further, the present invention provides a pawl-type starter wherein the pawl is effectively extended each time the starter rope is pulled, to induce the desired rotation of the engine shaft in the starting process.

Another important object of the present invention is to provide a pawl-type starter wherein the pawl will engage the engine only once each time the starter rope is pulled. Thus, even while the engine is running, a pull on the rope could extend the pawl into contact with the member on the engine shaft. However, the pawl will then be retracted by being overrun by the engine shaft member, and continuance of the pull on the rope will not again extend the pawl. This inadvertent pulling of the starter rope, while the engine is running, will not cause damage to the starter or the engine.

Still another feature of this invention is to provide a pawltype starter wherein the pawl is controlled by the lever, and the lever is limited in its movement, with such limitation being independent of the pawl itself. This feature avoids the inadvertent extension of the pawl from the pulley, it permits the pawl to retract into the pulley when the engine is running, and it precludes the inadvertent positioning of the lever.

A further feature of the present starter is in connection with the efficiency and reliability of the starter which is arranged to have the cooling air passing through the starter, but the usual dust and dirt carried by the engine cooling air is not permitted to reach the pawl or other critical operating parts of the starter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a preferred embodiment of this invention, and with the view being taken along the line 1-1 of FIG. 2.

FIG. 2 is a bottom plan view of a portion of FIG. 1.

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 1.

FIG. 4 is a perspective view of a fragment of the pulley in FIG. 1.

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4.

FIG. 6 is a perspective view of the pawl in FIG. 1.

FIG. 7 is a perspective view of the lever in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the engine shaft 10 having a fan 11 rotatable with the shaft 10 and carrying fan blades 12. An enclosure 13 extends around the fan 11, and a perforated piece 14 extends over the enclosure 13 and permits air to pass through the piece 14 which has air passage openings 16. Thus, the enclosure 13 has several spokes 15 which permit the air to pass downwardly through the starter and past the fan blades 12, and such spokes and such construction of the enclosure 13 are like that shown in US. Pat. No. 3,366,099. So cooling air enters the enclosure 13 through the openings 16 and flows into the member 13 and down to the fan blades 12, as shown by the arrows A. r

The enclosure 13 provides a mounting for a journal 17 adjacent the upper end of the shaft 10. A pulley 18 is rotatable on the journal 17, and a retainer member 19 and a snap ring 21 flank the pulley 18 to axially secure it relative to the shaft 10. A recoil spring 22 and a recoil spring housing 23 are located between the pulley 18 and the snap ring 21, and it will be understood that the recoil spring housing 23 is fixed with the nonrotatable sleeve or journal 17, such as shown by the interlocking ear 24 extending on the spring housing 23 in FIG. 2.

It will also be understood that the inner end of the coil spring 22 is anchored to the pulley 18, such as at the location 26, and the outer end of the coil spring 22 is anchored with the spring housing 23. Therefore, upon rotation of the pulley 18, the spring housing 23 remains in a fixed position but the coil spring 22 becomes wound so that upon release of the rotating force on the pulley 18, the recoil spring 22 will rewind the pulley 18. That is, a rope 27 is trained around the pulley 18 for the initial rotation of the pulley- 18 in starting the engine, all in a conventional manner and as more fully shown in said patent. Release of the pull on the rope 27 permits the recoil spring 22 to reverse the rotation of the pulley l8 and thereby rewind the rope 27 onto the pulley 18, as desired.

The improvement features of this invention reside in the provision of a pawl 28 and a control member or lever 29. The pawl 28 is pivotally received in a pocket 31 in the pulley 18 and on the under surface of the pulley 18. The pawl has a flat or planar side 32, and the opposite side of the pawl 28 has two angled surfaces 33 and 34. The pawl also has a flat surface 36 intermediate the flat surfaces 33 and 34. Further, the pawl has two ears or trunnions 37 which extend to opposite sides of the pawl.

The pulley pocket 31 has a main section 38 and it has two shoulders or surfaces 39. Further, the pocket has an inclined surface 41 and it has two additional shoulders 42, as best seen in FIG. 4. FIG. 1 shows that the bottom surfaces 43 of the trunnions 37 extend below the bottom surface 44 of the pulley 18. Also, the trunnion top surfaces 46 rest in abutment with the pocket shoulders 39 when the trunnion bottom surfaces 43 are below the plane of the pulley bottom surface 44. This therefore permits the lever 29 to be in contact with the trunnion bottom surfaces 43 when the pawl is pivotally extended as shown in FIGS. 1 and 3. The lever 29 therefore holds the pawl 28 securely in the pulley pocket 31, and the pawl can bear against the pocket walls 47 and 48, of FIG. 3, when the pawl is in driving engagement with the fan blade 12.

In the pivotally retracted position of the pawl 28, the pawl planar side 32 rests along the pocket inclined surface 41, as indicated by the dotted lines in FIG. 3. This permits the pawl to be clear of the fan blades 12, such as when the engine is running. Also, it will be understood that if the pawl 28 were extended in its full line position of FIG. 3 and the fan blade 12 were rotating in the conventional direction of rotation shown by the arrow B, then the blade would simply cause the pawl 28 to pivot to its parked or inoperative position shown by the dotted lines in FIG. 3, and there would be no damage to any parts.

FIGS. 2 and 7 show that the lever 29 includes an opening 49 which is large enough to permit the pivot of the pawl regardless of the position of the lever 29. The lever opening 49 is defined by lever portions 51 and 52 which are joined by a ramp portion 53. A;s Also, the lever 29 has a tang 54 which extends into a slot 56 formed in the pulley 18. The tang 54 and slot 56 limit the movement of the lever 29 relative to the pulley 18. Therefore, the pawl 28 is always under control by the lever 29 so that the pawl 28 will not fall from the pulley 18, but the lever 29 is limited in movement in both directions by virtue of the tang 54 and slot 56. The lever 29 is therefore centered with the sleeve 17 in that it has a ring 57 extending around the shaft and the shaft journal 17. The snap ring 21 holds the lever tab 63 snugly against the bottom surface 58 of the spring housing 23. FIGS. 1 and 2 further show that the spring housing surface 58 has ramps 59 spaced around the axis of the journal 17 and four such ramps are shown in FIG. 2. One side 61 of each ramp 59 has a gradual offset from the surface 58, while the ramp other side or edge 62 has a more abrupt offset from the surface 58. Also, it will be seen that the lever ring 57 has a tab 63 extending to a position of overlying the ramps 59, as shown in FIGS. 1 and 2.

With this arrangement, the pull on the rope 27 will cause the pulley 18 to rotate, and this will also cause the lever 29 to rotate since the lever ramp or offset portion 53 is in tight abutment with the corners 64 of the pawl trunnions 37, and this is when the pawl 28 is in the parked or dotted position of FIG. 3. The pulley 18 and lever 29 continue to rotate together in the direction of the arrow C in FIG. 2, until the lever tab 63 engages the ramp edge 62. At that point, the lever 29 is retarded in its rotation, and continued rotation of the pulley 18 causes the pawl 28 to pivot to its extended position of engagement with the fan blades 12. The lever 29 is of a spring material, and it therefore keeps snug contact with the pawl trunnion comers 64 to induce the pivot of the pawl as mentioned, and the lever 29 also remains in snug contact with the pawl trunnions 37 when the pawl is extended, all as shown in FIGS. 1, 2, and 3.

It should now be appreciated that if the fan blades 12 were to rotate faster than the rotation of the pulley 18, the blades would simply strike the extended pawl 28 and pivot the pawl to its parked position, since the lever 29 would permit the pawl to pivot upwardly without damage to any parts.

When the operator releases the rope 27, the recoil spring 22 causes the rewinding action mentioned. This again causes the lever 29 to rotate relative to the spring housing surface 58, but this time the rotation is opposite to the direction C, and therefore the tab 63 approaches the ramps 59 from the side designated 61. This arrangement permits the recoiled spring to easily rewind the rope 27 since the tab 63 does not present any restraining force in that it is moving over the very slight incline from the side 61 of the ramps 59. Nevertheless, the rewinding action causes the lever 29 to move relative to the pulley 18 so that the lever tang 54 moves from the one end of the slot 56, as shown in FIG. 2, and to the opposite end of the slot 56. The lever 29 is then in position to again pivot the pawl 28 outwardly when the rope 27 is again pulled. In the retracted position of the pawl, it will again be understood that the trunnions 37 are dimensioned so that they are in firm abutment with the shoulder 39 and they are also in firm abutment with the lever, so the pawl cannot fall into engagement with the fan blades 12. However, as mentioned, even if the pawl did become extended while the engine was running, the fan blades 12 would simply strike the pawl and cause it to return to its parked or retracted position. Therefore, in the pawl extended position, the trunnion surfaces 46 are in contact with the pocket surfaces 39, and in the pawl retracted position, the rounded trunnion surfaces 66 are in contact with the pocket surfaces 39.

It will therefore also be understood that the lever offset pot" tions 53 nest with the trunnion surfaces 64 to have a positive pivotal action of the pawl, as mentioned. Further, the lever 29 is not dependent upon the pawl 28 for correct positioning of the lever 29 since the lever 29 is located by means of the lever tang 54 and the pulley slot 56, rather than by limited movement through contact with the pawl 28. Still further, the pulley 18 provides the blind pocket 31 for the pawl 28 so that the pulley encloses the pawl 28 on the side which is upstream with respect to the flow of cooling air indicated by arrows A. This means that the pawl 28 and the pulley pocket 31 are protected against dust and dirt which would normally be carried by the cooling air. Also, the lever 29 is in a position to have its tab 63 on a ramp 59 when the starter is reset and ready for another starting action. Such position would be slightly off from the position shown in FIG. 2 and the tab 63 would actually be approximately centered with the ramp 59. This means that the lever 29 is held in a firm sprung position so that it firmly holds the pawl 28 in the parked or inoperative position. Also, the lever 29 is of a spring material, and its ring 57 is sprung by being slightly bent along the diametrical line 67 so that the ring 57 presents its apex at the line 67 adjacent the snap ring 21 and a ring 57 is therefore constantly urged toward the housing surface 58 to have the lever portions 51 and 52 constantly in firm contact with the pawl trunnions 37. That is, the lever 29 is sprung so that it is urged upwardly in FIG. 1, and it therefore takes up any clearance in the axial dimensions of the parts along the journal 17, and the lever always holds the pawl firmly upwardly to have the trunnions 37 in firm contact with the pocket surfaces 39, at all times.

Also, when the pawl is retracted, the trunnions are in contact with the shoulders 42, so the pawl is again held on the pulley. Tab 63 has an offset downtumed portion 68 for case of sliding movement onto and in contact with the ramp 59.

We claim:

1. A recoil type of internal combustion engine starter, comprising a rotatably mounted shaft, a pulley rotatable relative to said shaft, a rope on said pulley for rotating said pulley upon pulling on said rope, a recoil spring connected to said pulley for rotating said pulley to rewind said rope onto said pulley,

means on said shaft for transmitting a force of rotation to said shaft, a pawl pivotally mounted on said pulley to be retracted thereon and to also be extended therefrom into engagement with said means for transmitting the rotation of said pulley to said shaft through said means, a lever frictionally actuated by said pulley and movable relative to said pulley and said pawl and into a pawl actuating position for effecting the extended movement of said pawl when said pulley is rotated by a pull on said rope, said lever being in frictional contact with said pawl in the pawl actuating position of said lever, and said pawl being clear of said lever for pivot of said pawl to the retracted position on said pulley irrespective of the position of said lever.

2. The subject matter of claim 1, wherein said pawl includes trunnions on opposite sides thereof, said lever includes a portion in overlying contact with each of said trunnions for retaining said pawl on said pulley.

3. The subject matter of claim 2, wherein said pulley includes a pocket for receiving said pawl, surfaces on said pulley in abutment with said trunnions for pivotally retaining said pawl in conjunction with said lever portions.

4. The subject matter of claim 3, wherein said pulley includes a portion extending fully across said pocket on the side thereof opposite from the direction of the extension of said pawl from said pulley, for enclosing said side of said pocket to protect said pocket from the entrance of dirt.

5. The subject matter of claim 3, wherein saidlever includes angulated surfaceson said portions for engagement with said trunnions and for pivoting of said pawl upon movement of said lever.

6. The subject matter of claim wherein said trunnions and said surfaces are mutually angulated to nest portions of said trunnions with said angulated surfaces to alternately hold said pawl pivotally retracted on said pulley and topivot said pawl to the extended position when said lever moves over said pawl for extending said pawl.

7. The subject matter of claim 6, wherein said lever is of spring material for yieldingly urging against said trunnions and for releasing said pawl for pivot of said. pawl into the retracted position in response to a force on said pawl by said means when said means and said shaft rotate to overrun said pawl.

8. The subject matter of claim 7, wherein said means is a fan affixed to said shaft for rotation with said shaft, and said pawl extends from saidpulley to abut said fan.

9. The subject matter of claim 1, wherein said lever is of spring material and is coaxial in movement relative to the rotation of said pulley, a ramp surface included in said starter and disposed in the path of rotation of said lever for retarding rotation of said lever relative to said pulley to pivot said pawl.

10. The subject matter of claim 9, including a plurality of said ramp surfaces circumferentially spaced around said shaft, and said lever includes a tab projecting radially relative to said shaft and in sliding relation over said ramp surfaces upon rotation of said lever.

11. The subject matter of claim 10, wherein said tab has an edge offset from the remainder of said tab for meeting said ramp surfaces during rewinding of said pulley for ease of rewinding action.

12. The subject matter of claim 10, wherein said ramp surfaces have a first rise on the one side relative to the direction of movement of said tab over said ramp surfaces for extending said pawl, and said ramp surfaces have a second rise on the side opposite said one side, and with said second rise being more gradual than said first rise for easier sliding of said tab over said second rise in rewinding said pulley.

13. The subject matter of claim 10, wherein one of said ramp surfaces is located to be in contact with said tab when said lever is in a position of retaining said pawl retracted, to thereby flex said lever into a secure holding condition relative to the pawl.

14. The subject matter of claim 1, wherein said lever has an opening of size large enough for the pivot therethrough of said pawl when said lever is in the pawl actuating position. 15. The subject matter of claim 1, wherein said pawl includes trunnions on opposite sides thereof and on the pivot axis of said pawl, said lever includes a portion extending in contact with each of said trunnions, and said trunnions having flat surfaces in contact with said lever portions for holding said pawl in the retracted position after said pawl has been retracted and before said lever has been moved to pivot said pawl into the extended position.

16. The subject matter of claim 1, wherein said lever and said pulley have mutually engageable stops for limiting the movement of said lever relative to said pulley irrespective of the pivoted position of said pawl.

Claims

1. A recoil type of internal combustion engine starter, comprising a rotatably mounted shaft, a pulley rotatable relative to said shaft, a rope on said pulley for rotating said pulley upon pulling on said rope, a recoil spring connected to said pulley for rotating said pulley to rewind said rope onto said pulley, means on said shaft for transmitting a force of rotation to said shaft, a pawl pivotally mounted on said pulley to be retracted thereon and to also be extended therefrom into engagement with said means for transmitting the rotation of said pulley to said shaft through said means, a lever frictionally actuated by said pulley and movable relative to said pulley and said pawl and into a pawl actuating position for effecting the extended movement of said pawl when said pulley is rotated by a pull on said rope, said lever being in frictional contact with said pawl in the pawl actuating position of said lever, and said pawl being clear of said lever for pivot of said pawl to the retracted position on said pulley irrespective of the position of said lever.

5. The subject matter of claim 3, wherein said lever includes angulated surfaces on said portions for engagement with said trunnions and for pivoting of said pawl upon movement of said lever.

6. The subject matter of claim 5, wherein said trunnions and said surfaces are mutually angulated to nest portions of said trunnions with said angulated surfaces to alternately hold said pawl pivotally retracted on said pulley and to pivot said pawl to the extended position when said lever moves over said pawl for extending said pawl.

7. The subject matter of claim 6, wherein said lever is of spring material for yieldingly urging against said trunnions and for releasing said pawl for pivot of said pawl into the retracted position in response to a force on said pawl by said means when said means and said shaft rotate to overrun said pawl.

8. The subject matter of claim 7, wherein said means is a fan affixed to said shaft for rotation with said shaft, and said pawl extends from said pulley to abut said fan.

14. The subject matter of claim 1, wherein said lever has an opening of size large enough for the pivot therethrough of said pawl when said lever is in the pawl actuating position.

15. The subject matter of claim 1, wherein said pawl includes trunnions on opposite sides thereof and on the pivot axis of said pawl, said lever includes a portion extending in contact with each of said trunnions, and said trunnions having flat surfaces in contact with said lever portions for holding said pawl in the retracted position after said pawl has been retracted and before said lever has been moved to pivot said pawl into the extended position.