US2603201A

US2603201A - Sheetsxsheet i

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Publication number: US2603201A
Authority: US
Publication date: 1952-07-15
Anticipated expiration: 1969-07-15

Description

y 15, 1952 E. c. KI EKHAEFER 2,603,201

MAGNETO AND IGNITION FOR INTERNAL-COMBUSTION ENGINES Filed May 5, 1949 2 SI-IEETSSHE ET 1 flaw" j g i gv BY 56 m 3% Jf/krneys J ly 1953 i E. c. Kl-EKHAEFER 0 MAGNET-O AND IGNITION FOR INTERNAL-COMBUSTION ENGINES Filed May s, 1949- 2 SHEETSSl-1EET 2 I fi er/rays Patented July 15, 1952 MAGNETO AND IGNITION FOR INTERNAL- COMBUSTION ENGINES Elmer Carl Kiekhaefer, Cedarburg, Wis.

Application May 5, 1949, Serial No. 91,518

12 Claims. 1

This invention relates to internal combustion engines and particularly to the engine magneto and timer for engine ignition systems.

A principal object of the invention is to more fully protect the magneto and parts thereof from water, dust and the like which may interfere with the operation of the magneto and ignition of the engine and to ensure the operation of the engine under any severe or adverse weather conditions without ignition failure.

Another object is to enclose and seal the housing of the magneto, providing only a minute, con trolled' circulation of air through the same, so

that even momentary complete water-submersion of the magneto housing in severe weather operation will not interfere with the operation of the engine.

A further object is to seal fully the magneto housing at all other times so that even after a submersion of the entire engine the magneto will remain dry and operative. Y

Another object is to circulate air through the housing for the magneto including the breaker points of the timer to eliminate from the housing of certain types of magnetos the effects of prolonged operation which are injurious to the magneto and interfere with the operation of the timer.

Another object is to dispose the engine magneto with respect to certain parts of the engine to more adequately protect the magneto from dirt and moisture.

Another object is to filter or otherwise more positively ensure the removal of foreign particles from the air circulated through the magneto housing during engine operation.

These and other objects and advantages of the invention will be more fully set forth in the following description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a two-cylinder engine for an out- The engine shown in Fig. 1 for an outboard motor includes the crankcase l and cylinder block 2 provided with two parallel upper and lower cylinders 3 and 4. The vertical crankshaft 5 is journaled in bearings 6 and 1 in crankcase I and carries the flywheel 8 at the upper end. The pistons 9 operating within cylinders 3 and 4 are connected to crankshaft 5 by the connecting rods ID. The center crankshaft bearing and valve unit ll controls the induction of air and fuel from the carburetor 12 into the upper and lower crank chambers 13 and I4.

The engine is alternately fired by the spark plugs l5 which receive an electrical current impulse through wires l6 connected to the magneto unit ll. In the downstroke of each piston 9, the fuel mixture admitted by valve unit II is compressed within the respective crank chamber. At the end of the downward stroke the ports [8 in one side of the cylinders 3 and 4 are uncovered by pistons 9 to exhaust the burned gases. A passage IS in the other side of block 2 communicates respectively with each crankcase chamber and provides for transfer of thecompressed fuel from the chamber to the cylinder through ports 20.

The flange 2| cast integrally with crankcase I at the upper end thereof carries the circular base mounting plate 22 for magneto unit ll. Flange 2| is provided with a circular outer dimension having a center coinciding with the axis of crankcase 5 which passes therethrough. Plate 22 is carried by flange 2| so as to be adapted to be rotated with the handle 23 for timing adjustment of unit I! in relation to the engine.

The magneto unit [1 comprises the rotor 24 carried by and rotating with crankshaft 5, the stators 25 and the electrical timer switch 26 carried by mounting plate 22. The cam surface 21 provided near the upper end 28 of crankshaft 5 is provided to be engaged by the timer or switch 26 to operate the latter in timed relation to rotation of crankshaft 5.

The magneto housing or cover 29 is secured tightly to plate 22 and disposed to cover and enclose completely the magneto unit IT. The felt seal 30 is disposed within opening 3| in the top of cover 29 through which the crankshaft 5 extends and engages shaft 5 normally to close and seal the opening.

Ventilation of housing 29 is provided to prevent overheating and the accumulation of moisture within the housing and in certain types of magnetos to exhaust the ozone which is produced by the spark of the secondary timer switch. The ventilation is accomplished automatically and utilizes the intake cycle of the upper crank chamber I3. According to the invention the flange-type seal 32 at the upper end of crankcase I faces inwardly and engages the crankshaft to seal crank chamber l3 and prevent the escape of the compressed fuel mixture from the chamber. Seal 32 is adapted to be expanded inwardly against the crankshaft as the pressure within chamber |3 increases.

In the intake cycle of the crank chamber l3 a reduced pressure obtains so that the air and fuel mixture is drawn into the chamber from carburetor |2 through the valve unit H. During that period of time the greater (atmospheric) pressure on the outside of seal 32 causes the engagement of the seal with crankshaft 5 to be relaxed allowing a slight leakage of air into the crank chamber. This leakage, however slight, by reason of the enclosure of the magneto unit as described, is found to provide adequately the ventilation requirements of the magneto.

Various types of seals, other than that shown, may be employed effectively to allow the minimum desired leakage for the purposes of the invention which provides a negative pressure sufflcient to draw air past the felt seal into the housing. Dirt and foreign particles are excluded by seal 36 and the ventilation prevents the accumulation of excessive moisture within the housing.

In the embodiment of the invention shown in Fig. 2 the magneto and timer unit 33 is employed in the engine 34 which is of conventional fourcycle operation and includes the intake manifold 35.

The housing 36 completely enclosing magneto unit 33 is provided with a sealed opening 31 through which the operating shaft 38 extends. A second opening 39 is provided in the underside of housing 36 to receive the filter 40. The conduit 4| connects housing 38 andmanifold to provide a. passage preferably of small diameter therebetween. In the operation of the engine the induction vacuum within manifold 35 causes a small amount of air to be drawn through filter 40 and passed through housing 36 and conduit 4| to ventilate the magneto unit as described above.

The engine 42 shown in Figs. 3 and 4 is of twocycle operation and comprises the crankshaft 43 J'ournaled in

bearings

44 and 45 and the piston 46 reciprocating in cylinder 41 and connected to crankshaft 43 by means of the connecting rod 48.

The crankcase 49 carries crankshaft 43 in

bearings

44 and 45 on either side of the crank throw 50 operating in the crank chamber 5|. The induction system of the engine, not shown, includes chamber 5| in which the air is compressed with the downstroke of piston 46 for transfer to cylinder 41.

The flywheel 52 is carried at the end of crankshaft 43 opposite the power take-off end 53 and is provided with the fins 54 cast integrally with and extending radially from the circular body 55 of the flywheel.

The flywheel housing 56 receives the air discharged radially by the flywheel and directs the air over the fins 51 on the outside of cylinder 41 to cool the latter.

The magneto unit 58 supplying current to the spark plug 59 comprises the rotor 66 carried by and rotating with crankshaft 43, the stator 6| and the electrical timer switch or breaker 62 operated by the cam surface 63 of crankshaft 43. The base plate 64 carrying stator 6| and switch 4 62 is secured to the end of crankcase 49 by bolts, not shown, and has a central, round opening fitting the circular pilot boss 65 to provide limited rotational movement of the plate about the axis of crankshaft 2 to change the relative rotational positions of crankshaft 43 and timer switch 62 for adjustment of the engine firing.

The housing 66 carried by plate 64 is secured tightly thereto and is provided with the single opening 61 accommodating the crankshaft 43 and hub 68 of flywheel 52 to completely enclose the magneto unit.

The flange-type seal 69 is carried by crankcase 49 between the induction-crank chamber 5| and housing 66 with the lip 10 of the seal engaging crankshaft 43 and disposed to allow a nominal leakage of air from the induction system of the engine with each compression stroke of piston 46 to maintain a light pressure in housing 66 of magneto 58. In engines employing crankcase induction and precompression with efficiency, the negative pressures developed during induction are accordingly less than the corresponding positive pressure developed during precompression. Particularly at high speeds, slight amounts of air and fuel mixture pass the shaft seals outwardly of the engine because the pressure condition tends to predominate. At such times the air and fuel mixture will pass into the magneto housing 66 to displace the air therein as described without regard to the disposition of seal 69. The amount of fuel reaching and passing seal 69 is nominal and is insufficient to affect the operation of the magneto. Practically all of the liquid fuel entering the bearing opening is deposited on the bearings for lubrication thereof. The proportion of fuel to air reaching the seal is considerably less than that provided by the carburetor by reason of the centrifugal action of the crank arm and cheek of the crankshaft adjacent to the bearing which excludes a large amount of the liquid fuel therefrom.

The seal 1| carried by housing 66 within opening 61 engages hub 55 of flywheel 52 and serves to close opening 61 to prevent particles from passing through the opening into the housing and allows for the discharge of air from housing 66 to prevent excessive pressure therein.

The circulating system by-passing air from chamber 5| of the engine induction system through housing 66, as described, utilizes the usual air filter means, not shown, employed for removing dirt and moisture from the air prior to induction into the engine.

In applications of the engine such as chain saws where great amounts of wood dust is carried in the air, the relative location of opening 61 with respect to the flywheel-impeller 52 provides substantial additional protection of the magneto unit by reason of the rotational velocity of the air adjacent opening 61 which tends to cause dust particles to be propelled outwardly and away from opening 61.

Seal 32 or seal 69 may be employed in either engine or 42 for the controlled circulation of air through the respective magneto housing in either desired direction.

The invention provides the advantages of a practicable, positive and controlled means of ventilating the magneto housing with the operation of the engine, only to the extent that such ventilation may be required, allowing the magneto to be otherwise virtually fully closed and sealed.

In either chain saw or outboard motor magneto applications of this invention, when the engine is not in operation the magneto is, of course, closed to air, dirt, moisture and water.

Various embodiments of the invention may be employed within the scope of the accompanying claims.

I claim:

1. In an engine having a crankshaft, a crankcase, a crankcase fuel induction and compression system, said crankshaft extending from said crankcase, an ignition device for said engine carried by said crankcase and driven by said shaft, a housing for said ignition device supported by said crankcase and having a vent, a passageway between said crankcase and said housing, and means normally closing said passageway and responsive to the induction of said fuel system for providing limited circulation of air through said vent and said housing and into said crankcase.

2. In an engine having a crankcase, a crankcase fuel induction and compression system, an ignition control system, a housing for said control system having a vent, a passageway between said crankcase and said housing, and valve means normally closing said passageway and otherwise operable in timed relation to said engine and disposed to control said passageway whereby air entering said housing through said vent exhausts into said crankcase in response to the operation of said fuel induction system.

3. In an internal combustion engine having a crankcase, a crankcase induction system, and a crankshaft carried by said crankcase and having one end extending through an opening therefrom, a flywheel carried by said end of said crankshaft, electrical ignition means disposed between said crankcase and said flywheel and operated by said crankshaft, a housing enclosing said ignition means and having opposite openings for said crankshaft, a seal carried by said housing normally closing one of said openings and engaging said crankshaft adjacent said flywheel, said other opening registering with said crankcase opening and providing communication between said housing and crankcase induction system, and a seal normally closing said last named opening and being adapted to open during periods of maximum induction.

4. An internal combustion engine comprising a crankcase induction chamber, a crankshaft, a flywheel carried by said crankshaft, electrical ignition means operated by said crankshaft, a housing enclosing said ignition means and having-an opening adjacent the center of rotation of said flywheel, a passage providing communication between said housing and said crankcase chamber, and valve meansnormally closing said passage and opening the same in response to pressure conditions within said induction chamber different than that in said housing whereby air is circulated through said housing and said housing opening, said flywheel during operation of said engine serving to withdraw centrifugally foreign particles from the air passing adjacent said opening.

5. In an internal combustion engine having a crankcase, a crankcase induction system, and a crankshaft carried by said crankcase and having one end extending through an opening therefrom, a flywheel carried by said end of said crankshaft, electrical ignition means disposed between said crankcase and. said flywheel and operated by said crankshaft, a housing enclosing said ignition means and having opposite openings for said crankshaft, one of said openings being adjacent said flywheel, said other openin registering with said crankcase opening and providing communication between said housing and crankcase induction system, and a seal normally closing said last named opening and being adapted to open during periods of maximum induction whereby air is circulated through said housing from said first named opening, said flywheel during operation of said engine serving to induce the rotation about said crankshaft of the air entering said first named opening.

6. The combination with an internal combustion engine utilizing crankcase fuel induction and compression, which comprises a crankshaft operated magneto and ignition timer, a housing enclosing said magneto and timer secured to the engine crankcase and having opposite apertures for the crankshaft, one of said apertures registering with the crankcase opening accommodating the crankshaft, and an inwardly extending flange-type seal carried by the crankcase within said last named opening and engaging the crankshaft normally to close said opening and being adapted to open slightly during periods of fuel induction and allow limited quantities of air to be drawn through said housing,

7. In an engine, an induction system, a crankshaft, a flywheel carried by said crankshaft, a magneto and timer operatively carried by said crankshaft and adjacent said flywheel, a hous ing enclosing said magneto and timer and having an opening accommodating said crankshaft, means providing communication between said housing and said induction system whereby limited quantities of air adjacent said flywheel are drawn by said induction system through said vent into and through said housing, and a filter disposed within said vent precluding the entry of dust and the like into said housing during operation of said engine and otherwise closing said vent and housing.

8. In an internal combustion engine utilizing alternating crankcase air induction and compression and having a crankshaft extending through an opening in one wall of the crankcase, the combination which comprises a magneto and ignition timer operated by said crankshaft, a housing enclosing said magneto and timer and carried by the crankcase and having a vent and a second opening registering with said crankcase opening, and a flange-type seal closing said last named opening and having a lip engaging the crankshaft and disposed with respect to the crankcase to provide limited passage of air through said housing.

9. In an internal-combustion engine, a crankshaft, a crankcase therefor, air induction means including said crankcase subject to cyclic pressure changes, a magneto and ignition timing device operatively carried by said crank case and crankshaft, a housing enclosing said device secured to said crankcase having an opening for said crankshaft providing a passage between said crankcase and said housing, said housing having a second restricted opening allowing limited passage of air therethrough, and a flangetype seal carried within said first named opening in normal sealing engagement with said crankshaft and subject to slight opening in response to cyclic pressure changes within said crankcase whereby a limited amount of air is circulated through said housing in one direction.

10. In a two-cycle internal-combustion engine including a crankcase and employing crankcase precompression of the air and fuel mixture to effect scavenging and the recharging of the engine cylinder, electrical ignition means carried by said crankcase exteriorly thereof and including a cam to control said ignition means, a housing enclosing said ignition means and said cam and having a restricted vent opening to the atmosphere, and a restricted passage from said crankcase and opening into said housing and disposed to allow limited passage of gases through said opening into said housing to displace the gases therein through said restricted vent and maintain a nominal positive pressure in said housing to preclude the entry of moisture and foreign particles through said restricted vent into said housing.

11. In a two-cycle internal-combustion engine including a crankshaft and a crankcase and employing crankcase precompression of the air to effect scavenging and for the recharging of the engine cylinder with a fuel mixture, a bearing carried by said crankcase within an opening therein and journally supporting one end of said crankshaft projecting through said opening, electrical ignition means mounted on said crankcase exteriorly thereof and including a cam mounted on said end of the crankshaft adjacent to said bearing to control said ignition means, a housing enclosing said ignition means and said opening and having a restricted vent opening to the atmosphere, and a seal engaging said crankshaft and disposed within the opening of said crankcase between said bearing and said cam substantially closing said opening and otherwise allowing the limited passage of air under precompression through said opening into said housing to displace the air therein through said restricted vent and maintain a nominal positive pressure in said housing to preclude the entry of moisture and foreign particles through said restricted vent into said housing.

12. In a two-cycle internal-combustion engine including a crankshaft and a crankcase and cmploying crankcase induction and precompression of a fuel mixture to effect scavenging and for the recharging of the engine cylinder with a fuel mixture, a bearing carried by said crankcase within an opening therein and journally supporting one end of said crankshaft projecting through said opening, electrical ignition means mounted on said crankcase exteriorly thereof and including a cam mounted on said end of the crankshaft adjacent to said bearing to control said ignition means, a housing enclosing said ignition means and said opening and having a restricted vent opening to the atmosphere, and a seal engaging said crankshaft and disposed within the opening of saidcrankcase between said bearing and said cam normally closing said opening and otherwise allowing the limited passage of gases under precompression .through said opening into said housing to displace the gases therein through said restricted vent and maintain a nominal positive pressure in said housing to preclude the entry of moisture and foreign particles through said restricted vent into said housing, the centrifugal action of the crankshaft by rotation thereof serving to preclude substantial amounts of liquid fuel from said opening and from passing said seal into said housing.

ELhlER CARL KIEKHAEF'ER.

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

UNITED STATES PATENTS Number Name Date 1,430,524 Kettering Sept. 26, 1922 1,522,612 Burchett Jan. 13, 1925 1,638,146 Buchenberg Aug. 9, 1927 1,778,036 Noble et al. Oct. 14, 1930