US3150653A

US3150653A - Automatically rewinding engine starter

Info

Publication number: US3150653A
Application number: US58454A
Authority: US
Inventors: William H Barr
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-09-26
Filing date: 1960-09-26
Publication date: 1964-09-29
Anticipated expiration: 1981-09-29

Description

Sept. 29, 1964 w. H. BARR AUTOMATICALLY'REWINDING ENGINE STARTER Filed Sept. 26. 1960 3 Sheets-Sheet 1 INVENTOR.

Sept. 29, 1964 w. H. BARR AUTOMATICALLY REWINDING ENGINE STARTER 3 Sheets-Sheet 2 Filed Sept. 26, 1960 v INVENTOR. z/wwflm Sept. 29, 1964 w. H. BARR AUTOMATICALLY REWINDING ENGINE STARTER Filed Sept. 26. 1960 3 Sheets-Sheet "5 INVENTOR.

United States Patent 3,150,653 AUTOMATICALLY REWINDING ENGINE STARTER William H. Barr, 51 Liberty Pole Road, Hingham, Mass. Filed Sept. 26, 1950, Ser. No. 58,454 15 Claims. (Cl. 123-179) This invention relates to an improved mechanical self-starter for internal combustion engines in which the starter spring is automatically rewound by the engine as the engine operates.

The primary object of this invention is to provide a mechanical starter for internal combustion engines that will crank the engine for starting and then be re-energized automatically as the engine operates for subsequent starting.

Another object of this invention is to provide a mechanical self-starter for internal combustion engines that is energized by the operation of the engine and additional means for manually cranking the engine.

A further object is to provide a self-starter for such engines that does not require electric starting motors, batteries, generators, or electrical energy to operate.

Still another object is to provide a self-starter for such engines that is simple to operate and inexpensive to manufacture so that it is feasible for use on small engines that are ordinarily started manually using existing starting mechanisms.

Other objects and features of my invention will become apparent from the following description of forms shown in the drawing.

FIGURE 1 is a side cross section view of a first form of my invention in the condition for normal engine operation and rewinding of the starting spring.

FIGURE 2 is a partial side cross section view of the upper portion of the first and second forms of my invention shown in FIGURES 1 and 6 respectively with the starting knob and starting clutch half in position for automatically cranking the engine.

FIGURE 3 is a partial side cross section view of the upper portion of the first and second forms of my invention shown in FIGURES 1 and 6 in position for manually winding the starting spring.

FIGURE 4 is a top cross section view of the starting clutch half and crank arm of FIGURES 1 and 6.

FIGURE 5 is a top cross section view of the first form of -my invention shown in FIGURE 1.

FIGURE 6 is a side cross section view of a second form of my invention.

FIGURE 7 is a top cross section view of the second form of my invention.

Referring now to the first form of my invention as shown in FIGURES 1, 4, and 5, crank handle 4 is rotatably mounted on crank arm 3 which is mounted on the outside diameter of the cylindrical portion of housing arm 1 so that the crank arm is free to rotate or move axially with respect to the housing arm. The housing arm is firmly secured to the engine housing. Tension springs 7 draw the crank arm up against the mating shoulder of the housing arm. Starting knob 2 is secured to starting clutch half 5. The starting clutch half is mounted within the housing arm by a loosely fitting spline so that the starting clutch half may move axially but not rotate. Compression spring 6 presses the starting clutch half upwards so that the shoulder of the starting clutch half rests against the end of the cylindrical portion of the housing arm.

Intermediate clutch half 8 is moveably mounted to the flywheel cover 13 and engine drive shaft 16 so that it is free to rotate and move axially. Inertia wheel 10 is rotatably mounted on the intermediate clutch half and supported axially by compression spring 11 pressing upwards on the intermediate clutch half forcing the inertia wheel upwards against thrust washer 12 and the flywheel cover. The sawtooth clutch face 19 of the intermediate clutch half mates with the matching clutch face of the inertia wheel.

Screws 14 attach the flywheel cover to flywheel 15 mounted on the tapered portion of the engine drive shaft 16 by nut 17 and key 18. One end of starting spring 22 is secured to the intermediate clutch half by pin 21 which is firmly pressed into the intermediate clutch half, the other end of the starting spring being secured to the flywheel by pin 20 pressed into the flywheel. Unidirectional spring clutch 23 is wound with an inside diameter slightly smaller than the outside diameter of the inertia wheel and has one end fixed to the flywheel by the bent portion of the end protruding through a hole in the side of the flywheel. Thus the unidirectional spring clutch has one free end and the other end secured to the flywheel. If a torque is applied to the flywheel urging it in a direction to pull the unidirectional spring clutch after it, the coils of the unidirectional spring clutch tend to wrap tightly on the inertia wheel and will seize thereto, preventing relative rotation between the flywheel and the inertia wheel in this direction. However, if a torque is applied in an opposite direction urging it to push the unidirectional spring clutch before it, said coils will tend to loosen their grip on the inertia wheel and relative rotation in this direction between the flywheel and the inertia wheel is permitted with very low frictional resistance from the unidirectional spring clutch. This arrange ment comprising the unidirectional spring clutch and the inertia wheel permits the inertia wheel to rotate in a clockwise direction relative to the flywheel but prevents counterclockwise relative rotation of the inertia wheel when viewed from the top of the starter.

In the operating condition shown in FIGURE 1, this first form of my invention is in the position of normal engine operation and automatic rewinding of the starting string by the action of the inertia wheel. As the engine operates, the flywheel rotates in a clockwise direction viewed from the top of the starter.

The drive shaft of a conventional piston type internal combustion engine has cyclic rotational accelerations and decelerations as the engine operates, caused primarily by the inertial force of the oscillating pistons and connecting rods and the force resulting from the compression and explosion of the air-fuel mixture. Longer duration average accelerations and decelerations of the engine drive shaft occur as the engine is speeded up or slowed down.

Immediately after the engine has been started, the starting spring is unwound having spent its stored energy in cranking the engine. It must then be rewound to be in condition for subsequent starting of the engine. Automatic rewinding of the starting spring in the first form of my invention is accomplished in the following manner.

As the engine rotates in a clockwise direction the inertia wheel is driven by the engine driveshaft through the flywheel and the undirectional spring clutch. When the engine drive shaft is decelerated the inertia wheel tends to remain rotating at the maximum previous speed. The speed of the inertia wheel will then exceed the speed of the flywheel, rotating in a clockwise direction relative to the flywheel. The unidirectional spring clutch does not resist relative rotation in this direction. When this relative rotation occurs, the inertia wheel, coupled to the intermediate clutch half by the mating clutch teeth 19 rotates the intermediate clutch half with respect to the flywheel, winding the starting spring through the connections at pin 21 and pin 20.

The starting spring will continue to be wound in this manner each time the engine flywheel decelerates until the starting spring is wound sufliciently tight to provide a torque equal to the torque produced by the inertia wheel. The inertia wheel will then rotate with the flywheel, it being secured thereto by the unidirectional spring clutch and the starting spring.

FIGURE 2 is a partial side cross section view of of the upper portion of the two forms of my invention as shown in FIGURES l and 6, viewed from the same direction but modified by the starting knob and starting clutch half being depressed in position for starting the engine. In this condition, the starting clutch half is prevented from rotating in a counterclockwise direction with respect to the engine housing by the housing arm and spline and is engaged with the intermediate clutch half by mating clutch teeth 9. The intermediate clutch half has been depressed downward by the starting clutch half so that it no longer engages the inertia wheel. One end of the starting spring is secured in this manner to the flywheel by pin 20 and the other end secured to the engine housing through pin 21, the intermediate clutch half, mating clutch teeth 9 between the intermediate clutch half and the starting clutch half, the starting clutch half, the spline between the starting clutch half and the housing arm and thence the engine housing. The energy and torque of the tightly wound starting spring is thereby applied between the engine drive shaft and the engine housing to crank the engine in the proper direction for starting.

Once the engine has started and is operated under its own power, the starting clutch half is released from engagement with the intermediate clutch half by releasing the pressure on the starting knob, allowing compression spring 6 to force the starting clutch halt upwards. The intermediate clutch half is simultaneously engaged with the inertia wheel by the upwards pressure of spring 11. The engine starter is then in the condition as shown in FIGURES 1 and 6 for automatic rewinding of the starting spring as the engine operates. If the starting clutch half and knob are not released promptly after the engine has started, the starting spring is protected from excessive unwinding and possible breakage by the over-riding characteristic of the sawtooth clutch teeth 9 engaging the starting clutch half and the intermediate clutch half.

FIGURE 3 is a partial side cross section view of the upper portion of both forms of my invention as shown in FIGURES 1 and 6 with the starter in the condition for manually rewinding the starting spring. Manual rewinding would be necessary if the engine failed to start after the starting spring cranked the engine and spent the energy stored therein. The starting spring is rewound manually by pressing down on the crank handle 4 and arcuately rotating it back and forth until the starting spring is sufficiently rewound. This combined action engages the clutch teeth on the crank arm with the intermediate clutch teeth 9 and drives the intermediate clutch half in a clockwise direction, rewinding the starting spring. On the reverse stroke of the cranking operation, the starting spring is prevented from unwinding through the connection of the flywheel to the unidirectional clutch, the inertia wheel, the intermediate clutch half and pin 21. The rewinding torque is resisted by the engine inertia and friction and the compression of the air-fuel mixture in the cylinders. Any of the conventional devices used on other types of engine starters for locking the flywheel to the engine housing during manual rewinding of the starting spring may be used in combination with my starter to lock the flywheel against rotation as the starting spring is manually cranked.

FIGURE 6 is a partial side cross section view of a second form of my invention in the condition of normal engine operation and automatic rewinding of the starting spring. Elements identified by numerals 1 through 8 in FIGURES 1 through 4 of the drawing are only partially shown or not shown at all in FIGURE 6 but are used in this second form exactly as used in the first form and are identical thereto.

Referring to FIGURES 6 and 7, intermediate clutch half 8 is moveably mounted within the flywheel cover 13 and on the engine drive shaft 16. One end of starting spring 22 is fixed to the intermediate clutch half by pin 21 and the other end connected to the flywheel by pin 20. The intermediate clutch half is pressed upwards by spring 11 engaging the clutch faces 19 of the intermediate clutch half and the clutch drum 25. Unidirectional spring clutches 26 and 27 are wound with an inside diameter slightly smaller than the outside diameter of the clutch drum. Pin 28 pressed into the flywheel cover secures one end of the clutch spring 26 thereto. Pin 29 pressed into lever 31 secures one end of spring 27 thereto. Lever 31 is pivotally mounted on pin 30 which is pressed into the flywheel cover and the flywheel. Unidirectional spring clutch 26, having one end fixed to the flywheel and the other end free, operates as an overriding clutch, permitting the clutch drum to rotate in a direction relative to the flywheel to wind the starting spring and preventing relative rotation in the opposite direction. Similarly, undirectional spring clutch 27 has one end free and the other end secured to pin 29 on the end of lever 31, and permits the clutch drum to rotate in a direction relative to pin 29 to wind the starting spring and prevents relative rotation in the opposite direction. An oscillatory motion of pin 29 about pin 30 will cause the coils of unidirectional spring clutch 27 to oscillate about the engine drive shaft. When such oscillations take place, unidirectional spring clutch 27 will drive the clutch drum in a direction to wind the starting spring during one half of the oscillation cycle, and will freewheel on the clutch drum during the other half of the oscillation cycle, the clutch drum being prevented from rotating in a direction to unwind the starting spring by the action of unidirectional spring clutch 26. Rotary oscillatory motion between the inertia wheel and the flywheel is transmitted to unidirectional spring clutch 27 by lever 31.

Inertia wheel 33 is rotatably mounted within the flywheel and is limited in rotation by the ends of arcuate slot 33 in the inertia wheel and elastic bumper 36 mounted on pin 34 which is pressed into the flywheel and flywheel cover. Pin 32 pressed into the inertia wheel fits loosely in the slot in the end of the lever so that rotary motion of the inertia wheel with respect to the flywheel is transmitted to the lever causing it to rotate about pin 30.

Automatic rewinding of this embodiment employs the rotary accelerations and decelerations of the engine as it operates. Normal operation of the flywheel is in the clockwise direction. When the engine accelerates in the clockwise direction, the inertia wheel is driven by the flywheel either through pin 34, bumper 36 and the end of slot 38 or through pin 20, the starting spring, pin 21, the intermediate clutch half, the engaged clutch teeth 19 between the intermediate clutch half and the clutch drum, the clutch drum, unidirectional spring clutch 27, pin 29, lever 31 and pins 30 and 32. The inertia wheel will tend to remain rotating at its maximum rate of rotation if the flywheel decelerates, being free to do so within the limits of the arcuate slot 38 and bumper 36 and pin 34, the unidirectional clutch spring 27 overriding on the clutch drum, thereby permitting the lever to freely rotate in the clockwise direction relative to pin 30 and the inertia wheel to rotate in the clockwise direction relative to the flywheel.

When the engine accelerates in a clockwise direction after initial deceleration, the starting spring being substantially unwound, the inertia wheel will again tend to rotate counterclockwise with respect to the flywheel. The torque transmitted to the starting spring from the inertia wheel will rotate the starting spring, partially winding it. The clutch drum and hence the starting spring is prevented from unwinding by the reverse locking action of the unidirectional spring clutch 26. This winding process will continue with each cycle of engine deceleration and acceleration until the starting spring has been wound sufliciently tight so that the torque tending to rotate the clutch drum in the clockwise direction trans mitted from the inertia wheel is equal to the opposing torque transmitted to the clutch drum from the starting spring. The starting spring will then be wound for subsequent engine starting and the inertia wheel will be held in the extreme clockwise position relative to the flywheel against bumper 36.

While two forms of my invention have been described in detail, it is to be understood that its outstanding novel features are subject to wide latitude in practical application without departing from the spirit and scope of my invention.

I claim as my invention:

1. A mechanical starting device in combination with an internal combustion engine comprising a starting spring, means responsive to the rotational pulsations of said internal combustion engine for progressively incrementally winding the starting spring as the engine operates and means preventing unwinding of said starting spring after each increment of winding.

2. A device according to claim 1 including releasable means operatively coupling the starting spring to the engine housing.

3. A device according to claim 1 including means for manually rewinding the starting spring.

4. In combination with an internal combustion engine, a starting device comprising a starting spring, means for manually winding said starting spring, releasable means operatively coupling said starting spring between the engine drive shaft and the engine housing, and inertia means for winding said starting spring by the engine in response to cyclic angular velocity changes of the engine drive shaft during each cycle.

5. The combination of an internal combustion engine and a starting device comprising a starting spring, means for manually winding said starting spring, a first releasable means operatively coupling said starting spring between the engine drive shaft and the engine housing, inertia means movably mounted to the engine drive shaft and means coupling said inertia means to said starting spring for automatically winding said starting spring by the relative rotation between said inertia means and the engine drive shaft while cyclic changes in the rotational speed of the engine drive shaft occur, said relative rotation substantially ceasing when said starting spring is wound to a predetermined tension, and a second releasable means operatively coupling said starting spring between said inertia means and the engine drive shaft.

6. In combination with an internal combustion engine, a starting device comprising a starting spring, inertia means, a first clutch means unidirectionally connecting said inertia means to the drive shaft of the engine, a second clutch means releasably connecting said inertia means to a first end of said starting spring, means connecting a second end of said starting spring to said drive shaft, and a third clutch means releasably connecting said first end of said starting spring to the engine housing.

7. A device according to claim 6 wherein said third clutch means is engaged when said second clutch means is disengaged for cranking the engine.

8. A device according to claim 6 wherein said third clutch means comprises a unidirectional clutch opposing the unwinding of said starting spring when engaged therewith.

9. A device according to claim 6 wherein said second clutch means comprises a unidirectional clutch opposing unwinding of said starting spring when engaged with said inertia means.

10. A device according to claim 6 with means for manually Winding said starting spring.

11. The combination of an internal combustion engine having a drive shaft and a starting mechanism comprising a starting spring, inertia means operatively connected to a first clutch means, a first intermediate means rotatably mounted to the engine drive shaft, said first clutch means being unidirectionally connected to said first intermediate means, a second clutch means unidirectionally connecting said first intermediate means to the engine drive shaft, a second intermediate means rotatably mounted with respect to the engine drive shaft, a third clutch means releasably connecting said first intermediate means to said second intermediate means, means connecting said second intermediate means to a first end of said starting spring, means connecting a second end of said starting spring to the engine drive shaft, and a fourth clutch means releasably connecting said first end to the engine housing.

12, A device according to claim 11 wherein said inertia means is operatively connected to said first clutch means by connecting means pivotally mounted to the engine drive shaft for rotating said inertia means in a direction opposite to the direction of rotation of said first clutch means.

13. A device according to claim 11 wherein said inertia means is operatively connected to said first clutch means by means providing mechanical advantage between said inertia means and said first clutch means.

14. In combination with an internal combustion engine, a starting device comprising a starting spring, a mass operably responsive to cyclic engine accelerations and decelerations, a first releasable means connecting one end of said starting spring to said mass, means connecting the other end of said starting spring to the engine drive shaft, and second releasable means connecting said first releasable means to manually actuated means for rewinding said starting spring.

15. In an internal combustion engine having a rotatable member and a starting spring having one end secured thereto, said starting spring being normally rotatable with said rotatable member, the improvement comprising a mass associated with the other end of said starting spring, said mass being normally rotatable with the starting spring and clutching means between the mass and the rotatable member permitting incremental winding of the starting spring by momentary velocity differences between the mass and the rotatable member due to pulsations occurring during the engine cycle.

References Cited in the file of this patent UNITED STATES PATENTS 1,104,894 Hodgson July 28, 1914 1,135,694 Keller Apr. 13, 1915 1,137,358 Sinclair Apr. 27, 1915 2,042,841 Harmon June 2, 1936 2,744,586 Blankenburg May 8, 1956 2,987,057 Kopp June 6, 1961 3,010,443 Lyvers Nov. 28, 1961 FOREIGN PATENTS 388,025 Great Britain Feb. 14, 1933