US 3463134 A
Description (OCR text may contain errors)
Aug. 26, 1969 R. ZECHNALL ETAL LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE Filed Nov. 17, 1967 3 Sheets-Sheet 1 fire/r Arrow 5y Aug. 26, 1969 ZECHNALL ETAL I 3,463,134
LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE Filed Nov. 17, 1967 3 Sheets-Sheet 2 Aug. 26, 1969 R. ZECHNALL ETAL 3,463,134
LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE Filed Nov. 17, 1967 3 Sheets-Sheet :5
7'45, Arrow/[y United States Patent U.S. Cl. 123146.5 16 Claims ABSTRACT OF THE DISCLOSURE Light operated control means for the ignition circuit of a combustion engine are located spaced from the engine and its distributor and connected by light guiding means to the distributor where a rotating actuator interrupts the path of light falling into a light sensitive means.
BACKGROUND OF THE INVENTION It is known to control auxiliary operations, such as the ignition, of a combustion engine by apparatus having a source of light and a light sensitive element.
Control arrangements of this type have been successfully used for the ignition means of combustion engines, and have the advantage that mechanical contact engagement is eliminated.
The ignition means of a combustion engine serves the purpose of igniting the compressed air-fuel mixture, which is accomplished by an igniting spark of the spark plug projecting into each cylinder of the engine. In order to initiate the igniting operation, the light emitted by a source and directed at a light sensitive switching element, is influenced by an actuator part driven by the engine.
In one known construction, in which the energy required for the ignition is inductively stored in an ignition coil, the light-sensitive element interrupts at the moment in which ignition is desired, the circuit of the primary winding of the ignition coil so that a high voltage impulse is produced in the secondary winding and supplied to the spark plug.
In capacitive ignition arrangements, in which the ignition energy is capacitively stored, the light-sensitive element effects at the moment at which ignition is desired, discharge of a previously charged capacitor through the primary winding of the ignition coil, so that a high voltage impulse is produced in the secondary winding for producing the desired spark at the spark plug.
The use of light operated control means for initiating an ignition operation has the advantage that the mechanically operated distributor contacts can be eliminated. Mechanical distributor contacts have the disadvantage that they are frequently scorched or soiled with oil, which results in malfunction, and that due to friction, bouncing back, and gradual deterioration of the contact pressure, the ignition is not always initiated at the exact moment at which it is desired.
The German Ausle-geschrift 1,120,812 discloses the use of a source of light and of a light-sensitive switching element to replace a conventional mechanically operated distributor.
In the constructions of the prior art using light-operated control means in the ignition circuit of a combustion engine, the source of light and the light-sensitive electric switching element is directly mounted on the engine, and more particularly in the distributor housing of the same. The light-operated control means are subjected in this location to mechanical oscillations and heat, so that they rapidly deteriorate. For example, if an incandescent filament lamp is used as a source of light, the oscillations of the distributor will soon cause breaking of the filament and consequent failure of the ignition. In the event that the light-sensitive electric element is a photodiode, or a phototransistor, the heat in the region of the engine and distributor will detrimentally influence the operations of these elements and of the entire electric ignition apparatus, since diodes and phototransistors are greatly influenced by heat.
Furthermore, in the prior art it is necessary to secure the source of light and the light-sensitive electric element by screws or like fastening means to the distributor housing, so that the oscillations of the same causes loosening of the threaded connections causing changes in the positions of the light-operated control means, which also jeopardizes the trouble-free operation of the ignition.
SUMMARY OF THE INVENTION It is one object of the invention to provide a lightoperated control means for controlling an auxiliary operation of an engine, for example, the ignition of the compressed fuel-air mixture of a combustion engine, which is arranged and constructed in such a manner that the apparatus is not subjected to heat and oscillations produced by the engine and parts of the same.
Another object of the invention is to provide a lightoperated control means in which light emitted by a source is reliably guided to a light-sensitive element.
Another object of the invention is to arrange lightoperated control means spaced from the distributor of a combustion engine, and to guide the light by lightguiding means into the region of the distributor Where an actuator cyclically opens and closes the path of the light.
With these objects in view, the present invention relates to a light-operated control apparatus for controlling auxiliary operations of an engine, such as ignition or the injection of fuel.
One embodiment of the invention comprises a source of light and a light-sensitive means spaced from the engine, elongated light guiding means disposed between the source of light and the light-sensitive means, means for guiding light to the light-sensitive means along a path having a portion in the region of the engine, and actuating means moved by the engine across said portion of the path for cyclically varying the amount of light entering the lightsensitive means, and being spaced from the light-operated control means a predetermined distance.
Oscillations and heat produced by the engine and the actuating means, are not transmitted to the light-operated control means since the light-guiding means permits a substantial separation of the parts.
The term engine is used in the present application to define any engine or motor and its auxiliary devices, for example, a combustion engine and a distributor. The term light-guiding means is used in the present application to define means for guiding light not only along a straight path, but also along a curved path or around corners. For example, the light guiding means may include preferably flexible rods consisting of lightguiding longitudinal fibers, and tubular elements having inner reflecting mirror surfaces.
In the preferred embodiments of the invention, the light-guiding means include two light-guiding elements having first ends located opposite the source of light and a light-sensitive means, respectively, and second confronting ends forming a gap through which a revolving portion of a rotating actuating means cyclically passes. The revolving portion may be impermeable to light, or reflecting depending on the construction and arrangement of the two light-guiding elements. It is also advantageous to provide a lens in the gap between the light-guiding elements and to adjust the position of the lens when the position of light-guiding elements is adjusted.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is partly a circuit diagram, and partly an eleva vation, partially in section, illustrating one embodiment of the invention applied to the ignition system of a combustion engine;
FIG. 2 is a diagram illustrating a modified circuit which may be combined with the embodiment of the invention shown in FIG. 1;
FIG. 3 is a fragmentary cross sectional view illustrating a part of a second embodiment of the invention;
FIG. 4 is a fragmentary cross sectional view illustrating a part of a third embodiment of the invention;
FIG. 5 is a fragmentary plan view, partially in section, illustrating a fourth embodiment of the invention; and
FIG. 6 is a fragmentary sectional view of a detail taken on line VIVI in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to the embodiment of FIGS. 1 and 6, a combustion engine includes a cylinder block 2, and a distributor 1 whose housing 26 is secured by brackets 5 to the cylinder block 2. The engine has two cylinders provided with grounded spark plugs 3 and 4- which are connected with stationary contacts 6 and 7 of the distributor. A contact arm 8 cooperates with stationary contacts 6 and 7 and is mouned on an insulator 9 carried by the distributor shaft 10 which is driven by shaft 12 of the engine, as schematically indicated by the dash-and-dot line 11. Contact arm 8 alternately engages contacts 6 and 7 during rotation of shaft 10, and is connected by a contact spring 13 and a slide contact 14 with a line leading to the secondary winding 15 of an ignition coil 16 which has a primary winding 17. One pair of ends of windings 15 and 17 are grounded, and the other end of primary winding 17 is connected by a line to a light-sensitive electric switching means 18 which is also connected by a switch 19 to the positive terminal of a battery 20 whose negative terminal is grounded. Switch 19 also connects the positive terminal of the battery with one terminal of a source of light, shown to be a lamp 21 whose other terminal is grounded. The light-sensitive means 18 is .a photodiode connected in series with primary winding 17, main switch 19, and the battery 20. Instead of a photodiode, a phototransistor, and instead of an incandescent lamp 21, a glow discharge lamp, or luminescent diode may be used.
When no light enters light-sensitive means 18, it has a high resistance so that a small current flows through primary winding 17. When switch 19 is closed, lamp 21 lights up, and if light is guided by light-guiding means 22 from lamp 21 into light-sensing means 18 by light guiding means 22 in a manner which will be described hereinafter, the resistance of light-sensitive means 18 drops so that a high current flows through the primary winding. When the flow of light is interrupted, as will be described hereinatfer, the resistance of light-sensitive means 18 is greatly increased so that the flow of current through primary winding 17 is reduced to an extent corresponding to an interruption so that a high voltage impulse is induced in the secondary winding 15 of the ignition coil 16 which is transmitted through contacts 13, 14, contact arm 8, and one of the stationary distributor contacts 6 and 7 to either spark plug 3 or spark plug 4 so that the respective spark plug produces a spark for igniting the fuel-air mixture in the respective cylinder of the combustion engine.
.In accordance with the invention, the source of light 21 and the light-sensitive means 18 of the above-described light-operated control means are mounted on a support 23 spaced from the distributor 1 and the cylinders of the combustion engine 2, for example on the wall which separates the engine of a car from the drivers compartment. Consequently, neither heat nor oscillations produced by the combustion engine can detrimentally influence the sensitive elements 18 and 21. Light-guiding means 22 guide the light emitted by the source of light 21 along a path having a portion in the region of the distributor 1 into the light-sensitive means 18. In the embodiment of FIG. 1, two elongated light-guiding means 22 are provided. One light-guiding means ends in the wall of the distributor housing 26 and has an end 22 forming a gap 25 with the confronting end 22" of the other light-guiding means 22 which has a straight portion merging into a U-shaped portion. The end portion of the second light-guiding element 22 is secured by clamp 27 to a carrier plate 28 which is secured to the housing 26 and has a bearing for distributor shaft 10.
It will be seen that the light-guiding means 22 form a U-shaped path for the light, interrupted by gap 25 in which a lens 31 is located to guide light from end 22 into the end 22". The light-guiding means 22 may be composed of tubular elements having mirror reflecting inner surfaces, or may be light-guiding rods consisting of parallel longitudinally extending light-guiding fibers.
An actuating means 24 is secured to distributor shaft 10 and rotates with the same. Actuating means 24 has two light impermeable portions b separated by light permeable openings a between the same. When distributor shaft 10 rotates together with actuating means 24, the portions b and the portions a alternately pass through gap 25 between the ends 22' and 22" so that the How of light through light guiding means 22 is cyclically interrupted in synchronism with the engagement of contact arm 8 with stationary distributor contacts 6 and 7. Since the combustion engine has two cylinders, two light impermeable portions b, and two light permeable window portions a are provided.
Whenever the flow of light is interrupted by revolving portions b, the resistance of light responsive element 18 is rapidly increased, the current in the primary winding 17 is reduced, and a high voltage impulse passes through the respective distributor contact 6 or 7 to spark plug 3 or 4.
It is advantageous to provide a centrifugal governor 30 between distributor shaft 10 and the actuating means 24 for regulating automatically the timing of the ignition. The carrier plate 28 on which the second light-guiding element 22 is mounted is preferably automatically adjusted by a regulating device 29 which is connected to the suction inlet of the combustion engine and operated by negative pressure to automatically regulate the moment of ignition. Since the adjustment of the flexible end of the light-guiding element effects a displacement of the end 22" relative to lens 31, it is necessary to adjust the lens so that the light guided from the lamp 21 through the first light-guiding element 22 and passing through the end 22' of the same, is focused by lens 31 onto the displaced end 22" of the other light-guiding element 22.
Lens 31 is mounted on a curved support member 32 provided with a gear segment 32', as best seen in FIG. 6. Gear segment 32 meshes with a first portion of a pinion 34 whose second portion meshes with a gear segment 35 in the outer cylindrical surface of carrier plate 28. Pinion 34 has a shaft portion mounted in a bearing of a support plate 33 projecting from the wall 26 of the distributor. When the negative pressure adjusting device 29 displaces carrier plate 28 with the end 22 of the light-guiding element to vary the moment at which gap 25 is crossed by the portion b of the actuating means, the angular position of lens 31 is also automatically adjusted so that the light passing through the end 22' is reliably directed by lens 31 into the end 22", although the same is no longer exactly aligned with the end 22'. Due to the displacement of the beam of light between lens 31 and end 22" by the negative pressure control device 29, the moment at which a portion b passes the light path is changed, so that the light reaching the light-sensitive means 18 is sooner or later interrupted whereby the moment of ignition, and the timing of the same relative to the rotation of shaft 12 and of distributor shaft is varied.
Shielding walls 36 are provided in the distributor housing 26 to protect lens 31 and the ends of the light-guiding means 22 from dust.
In the above-described arrangement, the path of the light is interrupted by a portion b of the actuating means 24 at the moment in which ignition is desired. It is also possible to produce an ignition spark of the spark plugs 3, 4 by blocking the path of the light for the greater part of a rotation, and to open the light path at the moment of ignition. In such an arrangement, the circumferential length of the portions b is substantially greater than the circumferential length of the window portions a, and the control circuit is modified as shown in FIG. 2. The lightoperated control means include in addition to a photodiode 18, also a NPN transistor 40, a resistor 37, and a limiting resistor 38. Switch 19 connects the battery 20 with lamp 21, and also connects photodiode 18' through resistors 37, 38 with the positive terminal of the battery. The base collector path of transistor 40 is connected in parallel to resistor 37, and the emitter of transistor 40 is connected to the primary winding 17. A secondary winding is connected to the stationary distributor contacts 6, 7 and to the spark plugs, as described with reference to FIG. 1.
When switch 19 is closed, and the path of light formed by light-guiding means 22 and lens 31 is interrupted in the gap 25 by a light-impermeable portion of actuating means 24, the photodiode 18' has such a high resistance that the base of transistor 40 has a positive potential in relation to the emitter so that the emitter collector path becomes conductive and a current flows through primary winding 17. In the ignition moment, a window portion of the actuating means 24 passes through gap 25 and opens the path of the light so that the light entering photodiode 18 reduces the resistance of the same to such an extent that the base of transistor 40 has a negative potential in relation to the emitter. Consequently, the emitter collector path, and thereby the current flowing through primary winding 17 is interrupted so that the high voltage impulse is induced in secondary winding 15 which causes an igniting spark on one of the spark plugs 3 or 4, depending on the position of contact arm 8.
FIG. 3 illustrates modified parts of an embodiment which otherwise corresponds to the embodiment described with reference to FIG. 1. The source of light 21 is farther spaced from the light-sensitive means 18, and light-guiding elements 22a have angular ends mounted in the wall 26 of the distributor housing so that the end faces 22 and 22" are aligned along a chord of the cylindrical distributor wall and of the cylindrical wall b of actuating means 24a which rotates with the distributor shaft 10-. In order to permit the passage of light between the ends 22' and 22', the cylindrical wall b has pairs of openings a aligned along two chords. Light can pass from end 22' and through gaps 25 into end 22" only when the openings a of a pair of openings are aligned, as shown in FIG. 3. Since the ignition system is assumed to be used with a two-cylinder combustion engine, and the ignition impulse is to be given by opening the path of the light between the source of light 21 and the light-sensitive means 18, four openings a and four wall portions b are provided. During each revolution of actuating means 24a, the path of the light is twice opened and twice closed so that in each of the two cylinders, an igniting spark is produced at the respective spark plug 3 or 4, as described with reference to FIG. 1.
A lens 31 is advantageously provided to focus and direct the light rays from end 22 into end 22", since the distance between the ends 22, 22" is comparatively great.
The actuating means 24a shown in the embodiment of FIG. 3 are provided with vanes 41 disposed close to the inner surface of the distributor wall and produce an air current during rotation of the actuating means with the distributor shaft 10. If the light-guiding means 22a are fiber rods, dust is blown off the end faces 22, 22". If the light-guiding elements 22a are tubular and have inner mirror reflecting surfaces, the air current enters the tubular light-guiding element and blows dust out of the same, while simultaneously cooling the lamp 21 and the light responsive means 18.
FIG. 4 illustrates modified parts of another embodiment which otherwise corresponds to the embodiment shown in FIG. 1. The light-guiding elements 22b have portions symmetrically slanted at an angle a and mounted in bores of the cylindrical wall of the housing 26. The actuating means 24b has opposite light-reflecting portions 0 which are disposed to reflect light coming from the end 22 of the first light-guiding element into the end 22" of the second light-guiding element. The light-reflecting portions may be constructed as mirrors, or as prisms, and the portions of actuating means 24b between the reflecting portions 0 may be either nonreflecting, or windows. The ignition system controlled by the embodiment of FIG. 4 is again designed for a two-cylinder combustion engine, as described with reference to FIG. 1, and each of the reflecting portions 0 is correlated with one of the spark plugs 3 or 4 and assumes the operative position shown in FIG. 4 for the left reflecting portion 0 at the moment at which an ignition spark is desired while contact arm 8 engages the respective stationary distributor contact 6 or 7, as described with reference to FIG. 1. When no reflecting surface is located in the gap 25, the light beam projected from the end 22' of the first light-guiding element 22b cannot enter the end 22" of the second light guiding element 22b so that no light enters light-sensitive means 18.
If the embodiment of FIG. 4 is to be modified to effect ignition at the moment in which the light entering lightsensitive means 18 is interrupted, the portions 0 are made of a nonreflecting material, or with a surface layer consisting of such a material, while the wide circumferential portions between the portions 0 have to be made with a light-reflecting surface.
FIG. 4 shows cleaning means in the form of a brush 42 secured to the inner surface of the distributor wall 26 and positioned so that the reflecting surfaces of the revolving portions 0 are wiped off and cleaned by brush 42 during each revolution of actuating means 24b. It is advantageous to provide cleaning brushes, not shown, also on the rotating actuating means 24b to wipe off the end face 22', 22" if light-guiding fiber rods are used as light-guiding elements 22b. Such brushes may be secured to the actuating means anywhere between the light reflecting portions 0.
FIG. 5 illustrates a modified portion of another embodiment of the invention which otherwise corresponds to the arrangement shown in FIG. 1. The light-sensitive means 18" which must be a heat-resistant type, is mounted on the stationary carrier plate 28 with a heat insulating elastic dampening member 43 interposed so that light-sensitive means 18" is not subjected to oscillations and heat produced by the combustion engine. The lamp 21 is mounted spaced from the combustion engine and distributor 1 on a supporting structure including a support plate 44 and a pair of springs 45 secured to the outer surface of the distributor housing wall 26. A lightguiding means 220 guides the light emitted by a source of light 21 along a straight path toward the light-sensitive means 18", and is supported in a bore of housing wall 25. The inner end of light-guiding means 220 forms a gap with light-sensitive means 18 through which revolving portions of actuating means 24, not shown in FIG. 5, pass during rotation. In FIG. 5, a portion of the top wall of the distributor 1 is broken out to permit a view at the light-sensitive means 18" which is located in the interior of the distributor housing. Support plate 44 may be made of metal and grounded and connected to one terminal of lamp 21. Springs 45 prevent the transmission of oscillation to lamp 21, and the spacing between lamp 21 and the distributor can be suitably selected, since the transmission of light to the light-sensitive means 18" from the lamp 221 is asured by the lightguiding means 22c. Since no oscillations are transmitted to the lamp 21, it can be constructed as an incandescent filament lamp.
In a modified construction, not shown, the lamp 21 is resiliently mounted on the carrier plate 28 in the place of the light-sensitive means 18 of FIG. 5, and light-sensitive means 18" is mounted on a spring-supported plate, as shown for lamp 21 in the construction of FIG. 5. The light-guiding means 22c assures an accurate guidance of light emitted by lamp 21 into the light-sensitive means 18".
The ignition circuits shown in FIGS. 1 and 2 represent an induction ignition system, but it will be understood that a capacitive ignition system can also be used with all embodiments of the invention. The discharge of a capacitor and the correlated production of an igniting spark is obtained by means of a source of light and a light-sensitive means, connected by light guiding means, as explained above.
Instead of the mechanically controlled distributor including distributor arm 8 and stationary distributor contacts 6 and 7, a distributor having switching elements operated by light rays may be used. The actuating means 24 is not necessarily mounted on the distributor shaft 10, but may be driven directly from the shaft of the combustion engine and combined with the flywheel of the same, or the flywheel may be constructed with light-permeable and light-impermeable portions and serve as actuating means 24.
The precisely timed control impulse produced by the arrangement of the invention, may be used for controlling other auxiliary operations of a combustion engine instead of the ignition. For example, the fuel injection may be timed by impulses produced when the path of light between a source of light and a light-sensitive means is opened or closed by an actuating means in synchronism with the piston movements of a combustion engine.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of light-operated control apparatus, differing from the types described above.
While the invention has been illustrated and described as embodied in a control apparatus for controlling the ignition timing of a combustion engine by means of lightoperated control means which are spaced from the engine to prevent the transmission of oscillations and heat, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:
1. Light-operated control apparatus for a combustion engine, comprising, in combination, light-operated control means for controlling an auxiliary operation of said combustion engine, and including a source of light and light-sensitive electrical means responsive to light variations, at least a part of said light-operated control means mounted independently from and being spaced a predetermined distance from said combustion engine so that oscillations and heat produced by said combustion engine are not transmitted to said source of light or to said light-sensitive electrical means; elongated light-guiding means disposed between said source of light and said light-sensitive electrical means for conducting light by repeated total reflection, and guiding the rays of light emitted by said source of light to said light-sensitive electrical means along a predetermined path having a portion in the region of said combustion engine; actuating means moved by said combustion engine across said portion of said path for cyclically varying the amount of light entering the light-sensitive electrical means; and an electrical control circuit connected to said light-sensitive electrical means for influencing the auxiliary operation of said combustion engine when the amount of light entering said light-sensitive electrical means varies.
2. Control apparatus as claimed in claim 1 wherein said actuating means crosses said portion of said path at a point located between said source of light and a light entrance end of said light-guiding means.
3. Control apparatus as claimed in claim 1 wherein said actuating means crosses said portion of said path at a point located between the light exit end of said lightguiding electrical means and said light-sensitive means.
4. Control apparatus as claimed in claim 1 wherein said light-guiding means include two light-guiding elements, said elements having first ends located opposite said source of light and said light-sensitive electrical means, respectively, and second ends forming a gap; and wherein said actuating means passes cyclically through said gap so as to be spaced from said light-operated control means a distance determined by the selected length of said light-guiding elements.
5. Control apparatus as claimed in claim 1 wherein said engine includes means for rotating said actuating means; and wherein said actuating means includes at least one light permeable portion and at least one light impermeable portion cyclically passing across said portion of said path for opening and closing the same for the passage of light.
6. Control apparatus as claimed in claim 1 wherein said light-guiding means include two light-guiding elements, said elements having first ends located opposite said source of light and said light-sensitive electrical means, respectively, and second ends forming a gap; and wherein said actuating means has reflecting portion which cyclically passes through said gap for reflecting light from one of said light-guiding elements into the other; and wherein said actuating means is spaced from said lightoperated means a distance determined by the selected length of said light-guiding elements.
7. Control apparatus as claimed in claim 1 wherein said light-guiding means include two light-guiding elements, said elements having first ends located opposite said source of light and said light-sensitive electrical means, respectively, and second ends forming a gap; including at least one lens located in said gap; and wherein said actuating means passes cyclically through said gap so as to be spaced from said light-operated means a distance determined by the selected length of said lightguiding elements.
8. Control apparatus as claimed in claim 1 comprising automatic adjusting means controlled by said engine for adjusting the position of said light-guiding means so that the moment at which said light-operated control means controls said auxiliary operation is adjusted.
9. Control apparatus as claimed in claim 8 comprising at least one lens located in said path; means for supporting said lens for movement; and wherein said automatic adjustment means also adjusts the position of said lens.
10. Control apparatus as claimed in claim 1 including cleaning means for automatically cleaning said light-guiding means and carried by said actuating means.
11. Control apparatus as claimed in claim 1 wherein said actuating means include a reflecting portion; and including stationary cleaning means for cleaning said refleeting portion.
12. Control apparatus as claimed in claim 1 wherein said light-guiding means include tubular means having a reflecting inner surface; and wherein said actuating means include means for producing an air current directed into said tubular means.
13. Control apparatus as claimed in claim 1 including shielding means for protecting at least said light-guiding means from dust.
14. Control apparatus as claimed in claim 1 wherein said engine comprises ignition means having an electric circuit, and a rotary distributor shaft; wherein said lightoperated control means include switch means located in said circuit; and wherein said actuating means is mounted on said distributor shaft.
15. Control apparatus as claimed in claim 13 comprising a distributor housing; and resilient means for supporting at least a part of said light-operated control means on said housing spaced from the same so that heat and oscillations are not transmitted from said housing to said part of said light-operated control means.
16. Control apparatus as claimed in claim 1 wherein said combustion engine including a distributor and igniting means; comprising supporting means for said source of light and for said light-sensitive electrical means spaced from said distributor; wherein said light-guiding means include two light-guiding elements forming a gap in the region of said distributor and having ends, respectively, located adjacent said source of light and said light-sensitive means; wherein said actuating means rotates in timed relation with said engine and has at least one revolving portion passing through said portion of said gap; wherein said light-sensitive electrical means is adapted to vary its resistance under the influence of light; and a circuit including means connected to said light-responsive means, and through said distributor, to said igniting means for producing a spark in the latter When the resistance f said light-sensitive means varies.
References Cited UNITED STATES PATENTS 2,084,267 6/1937 Hicks. 3,163,700 12/1964 Williamson 8822.5
LAURENCE M. GOODRIDGE, Primary Examiner US. Cl. X.R.