Light activated sequential switching mechanism
United States Patent 3895612
A light actuated sequential switching mechanism for applying an energizing pulse in a predetermined order to each injector in an electronic fuel injection system on an internal combustion engine. A single source of radiant energy is sequentially applied to a plurality of radiant energy activating switching members each controlling the activation means of a fuel injector. A fiber optic conducting member "pipes" the radiant energy from the source to each switching member. The rotation of the distributor timing shaft provides the firing synchronism between the injector and the operation of the internal combustion engine.
US Patent References:
Radiation meter utilizing a dual surfaced detecting cell
Williamson - December 1964 - 3163700
Film reader with transparent capstan and u-shaped light conducting rod
Cannella - January 1968 - 3365580
IGNITION SYSTEM
Clyborne et al. - April 1969 - 3438362
LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE
Zechnall et al. - August 1969 - 3463134
/3587535.html
Kimberley et al. - June 1971 - 3587535
Radiation meter utilizing a dual surfaced detecting cell
Williamson - December 1964 - 3163700
Film reader with transparent capstan and u-shaped light conducting rod
Cannella - January 1968 - 3365580
IGNITION SYSTEM
Clyborne et al. - April 1969 - 3438362
LIGHT-OPERATED CONTROL APPARATUS FOR A COMBUSTION ENGINE
Zechnall et al. - August 1969 - 3463134
/3587535.html
Kimberley et al. - June 1971 - 3587535
Inventors:
Keely, William Arthur (Highland, MI)
Kreger Jr., Merle Manford (Liberty, PA)
Kreger Jr., Merle Manford (Liberty, PA)
Application Number:
05/480061
Publication Date:
07/22/1975
Filing Date:
06/17/1974
View Patent Images:
Export Citation:
Assignee:
The Bendix Corporation (Southfield, MI)
Primary Class:
International Classes:
F02D41/30; G02B6/35; G02B6/42; F02B29/00
Field of Search:
123/32EA,32AE,139E,146.5A,148E 250/227
Primary Examiner:
Myhre, Charles J.
Assistant Examiner:
Argenbright, Tony
Attorney, Agent or Firm:
Wells, Russel C.
Claims:
We claim
1. In a fuel injection system for an internal combustion engine, a light actuated sequential switching mechanism for sequentially activating the fuel injectors, said mechanism comprising:
2. In the light actuated sequential switching mechanism according to claim 1 wherein said source of light energy is a light emitting diode energized from the activation of the ignition system for the internal combustion engine.
3. In the light actuated sequential switching mechanism according to claim 1 wherein said fiber optic bundle has said ends mounted flush with said one and said other broadside surfaces repsectively.
4. In the light actuated sequential switching mechanism according to claim 1 wherein said light actuated switching members are phototransistors.
5. In the light actuated sequential switching mechanism according to claim 1 wherein said fiber optic bundle has said one end positioned at the axis of rotation of said one broadside surface and extends between said pair of spaced broadside surfaces to said other broadside surface near the periphery thereof.
6. In the light actuated sequential switching mechanism according to claim 1 wherein said source of radiant energy comprises at least two individual sources electrically connected in circuit for redundant energization.
7. In a fuel injection system for an internal combustion engine, a light actuated sequential switching mechanism for sequentially activating the fuel injectors, said mechanism comprising:
8. In the light actuated sequential switching mechanism according to claim 7 wherein said N degree angularly spacing between said fiber optic bundles is equal to an odd multiple of the quotient derived by dividing 360° by the number of injectors.
9. In the light actuated sequential switching mechanism according to claim 7 wherein said source of radiant energy comprises at least two individual sources electrically connected in circuit for redundant energization.
10. In the light actuated sequential switching mechanism according to claim 7 wherein said source of radiant energy is adapted to be energized from the activation of the ignition system for the internal combustion engine.
1. In a fuel injection system for an internal combustion engine, a light actuated sequential switching mechanism for sequentially activating the fuel injectors, said mechanism comprising:
2. In the light actuated sequential switching mechanism according to claim 1 wherein said source of light energy is a light emitting diode energized from the activation of the ignition system for the internal combustion engine.
3. In the light actuated sequential switching mechanism according to claim 1 wherein said fiber optic bundle has said ends mounted flush with said one and said other broadside surfaces repsectively.
4. In the light actuated sequential switching mechanism according to claim 1 wherein said light actuated switching members are phototransistors.
5. In the light actuated sequential switching mechanism according to claim 1 wherein said fiber optic bundle has said one end positioned at the axis of rotation of said one broadside surface and extends between said pair of spaced broadside surfaces to said other broadside surface near the periphery thereof.
6. In the light actuated sequential switching mechanism according to claim 1 wherein said source of radiant energy comprises at least two individual sources electrically connected in circuit for redundant energization.
7. In a fuel injection system for an internal combustion engine, a light actuated sequential switching mechanism for sequentially activating the fuel injectors, said mechanism comprising:
8. In the light actuated sequential switching mechanism according to claim 7 wherein said N degree angularly spacing between said fiber optic bundles is equal to an odd multiple of the quotient derived by dividing 360° by the number of injectors.
9. In the light actuated sequential switching mechanism according to claim 7 wherein said source of radiant energy comprises at least two individual sources electrically connected in circuit for redundant energization.
10. In the light actuated sequential switching mechanism according to claim 7 wherein said source of radiant energy is adapted to be energized from the activation of the ignition system for the internal combustion engine.
Description:
BACKGROUND OF INVENTION
1. Field of the Invention
This invention relates to electromechanical triggering mechanisms in general and more particularly to light actuated switching systems using light conducting rods for use in a fuel injection equipped internal combustion engine.
2. Description of the Prior Art
Several devices utilizing sources of illumination energy and photo responsive members are found in the distributor art of internal combustion engines. Many have a single light source usually placed outside of the distributor housing and a single photo cell also stationarily mounted. The light is then piped from the source, across a path along which one or more members move to the cell. By the movement of the members along the path, a light chopping action is supplied to the cell.
One particular distributor system utilizes a single light source, a long complicated light piping system, a lens system, a movable member having a plurality of slots moving along the path and a single photo or light responsive member. Both the light source and the responsive member are positioned outside of the distributor housing and require a generally U-shaped light piping arrangement. As the moving member passes between the lens system and an open end of the light piping system, the light energy is removed from the light responsive member. The single member output requires a further means to segregate and apply the output pulses to various spark plugs for proper sequential operation.
Other systems utilize a rotating disc having a plurality of apertures therein moving between a light source and a photo cell. As a result of the pattern of spaced apertures, a chopping light signal is transmitted to the photo cell. Since there is only one photo cell, additional means must be developed to separate the several pulses from the cell.
SUMMARY OF THE INVENTION
It is a principal object of this invention to position a single source of radiant energy and a plurality of radiant energy responsive members and to distribute by means of a fiber optic bundle, the radiant energy to each responsive member in a predetermined sequence.
It is another object of this invention to provide a breakerless high reliable pulse generating system for controlling the fuel injectors in a fuel injection system.
It is a further object of this invention to reduce the complexity of both the mechanical and electronic members of a reliable pulse generating system by utilizing only one moving member and plurality of stationary activating members each respectively electrically coupled to an injector.
These and other objects of the invention will become apparent from the following drawings, detailed description and claims of a light activated sequential switching system for use in a fuel injection system of an internal combustion engine. A shaft is coupled at one end for rotation with the distributor timing shaft and has at the other end a disc member having a pair of spaced broadsides. Radially extending from the center of the disc to the periphery is a light conducting channel of fiber optic members. One end of the members is flush with the one broadside surface of the disc at the center thereof and opposite the shaft and the other end of the members is flush with the other broadside of the disc and near its periphery. A source of radiant energy is positioned opposite the one end of the bundle and a plurality of light responsive members are positioned to receive the radiant energy emitting from the other end of the bundle.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings
FIG. 1 is a plan view of the rotating member with several adjacent members removed for clarity;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1 with the housing and light source shown;
FIG. 3 is a plan view of one embodiment of the printed circuit board supporting the light responsive members;
FIG. 4 is another embodiment of the rotating member illustrating two fiber optic bundles;
FIG. 5 is another embodiment illustrating the use of a redundant radiant energy source;
FIG. 6 is a circuit for controlling the radiant energy sources of FIG. 5.
DETAILED DESCRIPTION
Referring to the Figs. by the characters of reference there is illustrated in FIG. 2 in sectional form the light actuated sequential switching mechanism 10 of the present invention. As illustrated in FIG. 2 the switching mechanism is enclosed in a housing 12 for the purposes of protecting the mechanism from dirt, grime and other foreign materials.
The mechanism comprises a shaft 14 which is coupled for rotation with the distributor timing shaft of an internal combustion engine 16. At essentially the free end 18 of the shaft 14 there is positioned by means of a pin 20 or other suitable fastening means a disc shaped member 22 having a pair of spaced broadside surfaces 24 and 26. One surface 24 is mounted substantially flush with the free end 18 of the shaft 14 and opposite the coupling end of the shaft 14. As indicated the disc 22 is mounted for rotation with the shaft. Spaced from and axially in line with the free end 18 of the shaft 14 is a source of light or radiant energy 28 which is directed toward the one broadside surface 24 of the disc 22. Formed or molded within the disc 22 and extending between the two broadside surfaces 24 and 26 is a fiber optic bundle 30. One end 32 of the fiber optic bundle 30 is axially in line with the radiant energy source 28. The other end 34 of the fiber optic bundle 30 is flush with the other broadside surface 26 of the disc 22 and near the periphery thereof. Spaced from the other broadside surface 26 of the disc is a supporting means 36 for supporting a plurality of light actuated switching members 38 wherein each switching member 38 is sequentially adapted to be in line with the other end 34 of the fiber optic bundle 30.
The shaft 34 of the mechanism 10 as illustrated in FIG. 2 is coupled by means not shown to the crankshaft of the internal combustion engine 16. In this manner the shaft 14 will rotate synchronously with the rotation of the crankshaft of the internal combustion engine 16. One such shaft 14 may well be the distributor timing shaft and in a preferred embodiment of the present invention this shaft is an extension of the distributor timing shaft. This shaft 14 is suitably journaled for rotation by well known means which are not illustrated in the Fig.
As indicated the disc shaped member 22 is secured to the shaft 14 by means of a collar 40 or other fastening means. In the preferred embodiment there is a concentric collar 40 having an aperture therein for receiving the free end 18 of the shaft 14 and in order to provide a positive rotation of the disc 22. With the shaft 14, conventional pinning means 20 is provided for securing the disc to the shaft. The disc 22 is fabricated from some nonmetallic material which is capable of being molded into the desired shape including the fiber optic bundle 30. The material used for the disc shaped member 22 and the method of manufacturing are illustrations of one form which the disc may take.
Formed within the disc 22 and molded thereto and extended in a substantially radial direction from the center of the disc is the fiber optic bundle 30. The bundle 30 comprises many strands of fiber optic material and collectively they extend from the center portion of the one broadside 24 of the disc through the disc 22 and out the other broadside 26 of the disc near the periphery thereof. Thus by this configuration and in a manner well known in the art the fiber optic bundle 30 will receive radiant energy on one side 24 of the disc 22, transmit the energy through the disc, and have it emit from the other side 26 of the disc. As illustrated in the plan view of FIG. 1, this fiber optic bundle 30 extends in a substantially radial direction.
Referring again to FIG. 2, there is illustrated the mounting 42 and supporting of the source of radiant energy 28 in a manner overlying the one end 32 of the fiber optic bundle 30. As illustrated in FIG. 2, the source of radiant energy 28 is axially in line with the free end 18 of the shaft 14. In the preferred embodiment, the source is a light bulb and enclosed in a housing 42 which may assist in directing the light energy from the bulb to the fiber optic bundle 30. In lieu of a light bulb other such devices as light emitting diodes may be used under proper conditions.
Referring to FIG. 3 there is illustrated the supporting member 36 in the form of a printed circuit board which supports and maintains the plurality of light actuated switching members 38. The number of switching members 38 is equal in number to the number of fuel injectors in a fuel injection control system 44 or the number of spark plugs and each are respectively connected in electrical circuit to each of the fuel injectors. Extending from one edge 46 of the printed circuit board 36 is a connector means 48 for electrically connecting the light actuated switching members 38 to the fuel injector control 44. Since the disc member 22 rotates about the shaft 14, the light actuated switching members 38 are positioned in a circumferential spaced apart relationship concentric with the clearance hole 50 for the shaft 14 located in the center of the board 36. The switching members 38 are so positioned on the board 36 and the board is so positioned in the relationship to the rotating disc shaped member 22 such that each light actuated switching member 38 is positioned so as to receive light emanating from the one end 34 of the fiber optic bundle 30 when that end 34 and the switching member 38 are in line relative to each other.
In the preferred embodiment the source of radiant energy 28 is energized whenever the ignition system 51 of the internal combustion engine 16 is turned on. As the distributor shaft 14 begins to rotate, the disc shaped member 22 also rotates and through means of the fiber optic bundle 30 transmits light energy from the radiant energy source 28 to each light actuated switching member 38 in sequential relationship. The signals generated by the light actuating switching members 38 are applied to individual injectors in the fuel injection control system 44 of the internal combustion engine 16.
Referring to FIG. 4 there is illustrated a modification in the positioning of the fiber optic bundles 52 and 54 within the disc shaped member 56. Particularly illustrated in FIG. 4 is the use of two fiber optic bundles 52 and 54 both beginning or receiving radiant energy at the center of the disc 56 and transmitting the energy to the opposite side of the disc near its periphery. With the use of two fiber optic bundles 52 and 54, as illustrated in FIG. 4, the number of light actuated switch members 38 will be reduced accordingly. Referring to FIG. 3 and using the disc 56 of FIG. 4 every other light actuated switching member 38 in FIG. 3 may be removed. The angle N between each fiber optic bundle 52 and 54 is equal to an odd multiple of the quotient found by dividing 360° by the number of injector actuated circuits in the fuel injector control system 44 required for the particular internal combustion engine 16. For example in an eight cylinder engine using two fiber optic bundles the angle N may be any odd multiple of the angle 45°. As illustrated in FIG. 4 the angle N is approximately 135° and the angular spacing of the light actuated switching members is 90°. If such a configuration was used in a six cylinder engine the angle N would be 60° and the angular spacing of the light actuated switching members 38 would be 120°.
Referring to FIG. 5 there is illustrated a modification for mounting at least two sources of radiant energy 58 and 60 in a redundant configuration. As illustrated in FIG. 5 by the use of two radiant energy sources this provides an insurance of one source if the other source fails. It is important in the mounting of the two sources 58 and 60 within their own housing 62 that all the radiant energy emitted by either source is directed toward the receiving surface 32 of the fiber optic bundle 30 on the disc 22. Thus as illustrated in FIG. 5 each source 58 and 60 is mounted to a surface which is slightly inclined toward the projected axis of the shaft 14.
Referring to FIG. 6, there is illustrated an electrical circuit 64 for controlling the dual radiant energy sources 58 and 60 of FIG. 5. The circuit of FIG. 5 is arranged so that when power is applied to the circuit 64 the first radiant energy source 58 is energized. The transistor Q1 66 is turned on driving its collector near ground. With the collector of the transistor Q1 66 near ground the second radiant energy source 60 is not energized. When the first radiant energy source 58 burns out or is extinguished, the voltage at the junction 68 of the radiant energy source 58 and its series resistor 70 rises toward the source voltage. This increasing voltage signal is reflected across the capacitor 72 to the base of the transistor Q2 74 driving it into conduction. When the transistor Q2 74 is turned on, its collector approaches ground, grounding the base of the transistor Q1 66, turning it off. When the transistor Q1 66 is driven out of conduction the second radiant energy source 60 is immediately energized through its series resistor 76 from the power source. Subsequent turning on of the transistor Q2 74, the source of power is supplied through the two resistors 76 and 78 in series with the base of the transistor Q2 74 thereby causing the second source of radiant energy 60 to be energized.
There is thus shown and described a light actuated sequential switching mechanism for use in a fuel injection system. The mechanism is used to sequentially energize fuel injectors in the system in synchronism with the demand of the internal combustion engine. The mechanism thus illustrated and described is particularly applicable to individual injector actuation, however the mechanism may be modified for multiple group actuation by the proper positioning and controlling of the light actuated switching members.
1. Field of the Invention
This invention relates to electromechanical triggering mechanisms in general and more particularly to light actuated switching systems using light conducting rods for use in a fuel injection equipped internal combustion engine.
2. Description of the Prior Art
Several devices utilizing sources of illumination energy and photo responsive members are found in the distributor art of internal combustion engines. Many have a single light source usually placed outside of the distributor housing and a single photo cell also stationarily mounted. The light is then piped from the source, across a path along which one or more members move to the cell. By the movement of the members along the path, a light chopping action is supplied to the cell.
One particular distributor system utilizes a single light source, a long complicated light piping system, a lens system, a movable member having a plurality of slots moving along the path and a single photo or light responsive member. Both the light source and the responsive member are positioned outside of the distributor housing and require a generally U-shaped light piping arrangement. As the moving member passes between the lens system and an open end of the light piping system, the light energy is removed from the light responsive member. The single member output requires a further means to segregate and apply the output pulses to various spark plugs for proper sequential operation.
Other systems utilize a rotating disc having a plurality of apertures therein moving between a light source and a photo cell. As a result of the pattern of spaced apertures, a chopping light signal is transmitted to the photo cell. Since there is only one photo cell, additional means must be developed to separate the several pulses from the cell.
SUMMARY OF THE INVENTION
It is a principal object of this invention to position a single source of radiant energy and a plurality of radiant energy responsive members and to distribute by means of a fiber optic bundle, the radiant energy to each responsive member in a predetermined sequence.
It is another object of this invention to provide a breakerless high reliable pulse generating system for controlling the fuel injectors in a fuel injection system.
It is a further object of this invention to reduce the complexity of both the mechanical and electronic members of a reliable pulse generating system by utilizing only one moving member and plurality of stationary activating members each respectively electrically coupled to an injector.
These and other objects of the invention will become apparent from the following drawings, detailed description and claims of a light activated sequential switching system for use in a fuel injection system of an internal combustion engine. A shaft is coupled at one end for rotation with the distributor timing shaft and has at the other end a disc member having a pair of spaced broadsides. Radially extending from the center of the disc to the periphery is a light conducting channel of fiber optic members. One end of the members is flush with the one broadside surface of the disc at the center thereof and opposite the shaft and the other end of the members is flush with the other broadside of the disc and near its periphery. A source of radiant energy is positioned opposite the one end of the bundle and a plurality of light responsive members are positioned to receive the radiant energy emitting from the other end of the bundle.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings
FIG. 1 is a plan view of the rotating member with several adjacent members removed for clarity;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1 with the housing and light source shown;
FIG. 3 is a plan view of one embodiment of the printed circuit board supporting the light responsive members;
FIG. 4 is another embodiment of the rotating member illustrating two fiber optic bundles;
FIG. 5 is another embodiment illustrating the use of a redundant radiant energy source;
FIG. 6 is a circuit for controlling the radiant energy sources of FIG. 5.
DETAILED DESCRIPTION
Referring to the Figs. by the characters of reference there is illustrated in FIG. 2 in sectional form the light actuated sequential switching mechanism 10 of the present invention. As illustrated in FIG. 2 the switching mechanism is enclosed in a housing 12 for the purposes of protecting the mechanism from dirt, grime and other foreign materials.
The mechanism comprises a shaft 14 which is coupled for rotation with the distributor timing shaft of an internal combustion engine 16. At essentially the free end 18 of the shaft 14 there is positioned by means of a pin 20 or other suitable fastening means a disc shaped member 22 having a pair of spaced broadside surfaces 24 and 26. One surface 24 is mounted substantially flush with the free end 18 of the shaft 14 and opposite the coupling end of the shaft 14. As indicated the disc 22 is mounted for rotation with the shaft. Spaced from and axially in line with the free end 18 of the shaft 14 is a source of light or radiant energy 28 which is directed toward the one broadside surface 24 of the disc 22. Formed or molded within the disc 22 and extending between the two broadside surfaces 24 and 26 is a fiber optic bundle 30. One end 32 of the fiber optic bundle 30 is axially in line with the radiant energy source 28. The other end 34 of the fiber optic bundle 30 is flush with the other broadside surface 26 of the disc 22 and near the periphery thereof. Spaced from the other broadside surface 26 of the disc is a supporting means 36 for supporting a plurality of light actuated switching members 38 wherein each switching member 38 is sequentially adapted to be in line with the other end 34 of the fiber optic bundle 30.
The shaft 34 of the mechanism 10 as illustrated in FIG. 2 is coupled by means not shown to the crankshaft of the internal combustion engine 16. In this manner the shaft 14 will rotate synchronously with the rotation of the crankshaft of the internal combustion engine 16. One such shaft 14 may well be the distributor timing shaft and in a preferred embodiment of the present invention this shaft is an extension of the distributor timing shaft. This shaft 14 is suitably journaled for rotation by well known means which are not illustrated in the Fig.
As indicated the disc shaped member 22 is secured to the shaft 14 by means of a collar 40 or other fastening means. In the preferred embodiment there is a concentric collar 40 having an aperture therein for receiving the free end 18 of the shaft 14 and in order to provide a positive rotation of the disc 22. With the shaft 14, conventional pinning means 20 is provided for securing the disc to the shaft. The disc 22 is fabricated from some nonmetallic material which is capable of being molded into the desired shape including the fiber optic bundle 30. The material used for the disc shaped member 22 and the method of manufacturing are illustrations of one form which the disc may take.
Formed within the disc 22 and molded thereto and extended in a substantially radial direction from the center of the disc is the fiber optic bundle 30. The bundle 30 comprises many strands of fiber optic material and collectively they extend from the center portion of the one broadside 24 of the disc through the disc 22 and out the other broadside 26 of the disc near the periphery thereof. Thus by this configuration and in a manner well known in the art the fiber optic bundle 30 will receive radiant energy on one side 24 of the disc 22, transmit the energy through the disc, and have it emit from the other side 26 of the disc. As illustrated in the plan view of FIG. 1, this fiber optic bundle 30 extends in a substantially radial direction.
Referring again to FIG. 2, there is illustrated the mounting 42 and supporting of the source of radiant energy 28 in a manner overlying the one end 32 of the fiber optic bundle 30. As illustrated in FIG. 2, the source of radiant energy 28 is axially in line with the free end 18 of the shaft 14. In the preferred embodiment, the source is a light bulb and enclosed in a housing 42 which may assist in directing the light energy from the bulb to the fiber optic bundle 30. In lieu of a light bulb other such devices as light emitting diodes may be used under proper conditions.
Referring to FIG. 3 there is illustrated the supporting member 36 in the form of a printed circuit board which supports and maintains the plurality of light actuated switching members 38. The number of switching members 38 is equal in number to the number of fuel injectors in a fuel injection control system 44 or the number of spark plugs and each are respectively connected in electrical circuit to each of the fuel injectors. Extending from one edge 46 of the printed circuit board 36 is a connector means 48 for electrically connecting the light actuated switching members 38 to the fuel injector control 44. Since the disc member 22 rotates about the shaft 14, the light actuated switching members 38 are positioned in a circumferential spaced apart relationship concentric with the clearance hole 50 for the shaft 14 located in the center of the board 36. The switching members 38 are so positioned on the board 36 and the board is so positioned in the relationship to the rotating disc shaped member 22 such that each light actuated switching member 38 is positioned so as to receive light emanating from the one end 34 of the fiber optic bundle 30 when that end 34 and the switching member 38 are in line relative to each other.
In the preferred embodiment the source of radiant energy 28 is energized whenever the ignition system 51 of the internal combustion engine 16 is turned on. As the distributor shaft 14 begins to rotate, the disc shaped member 22 also rotates and through means of the fiber optic bundle 30 transmits light energy from the radiant energy source 28 to each light actuated switching member 38 in sequential relationship. The signals generated by the light actuating switching members 38 are applied to individual injectors in the fuel injection control system 44 of the internal combustion engine 16.
Referring to FIG. 4 there is illustrated a modification in the positioning of the fiber optic bundles 52 and 54 within the disc shaped member 56. Particularly illustrated in FIG. 4 is the use of two fiber optic bundles 52 and 54 both beginning or receiving radiant energy at the center of the disc 56 and transmitting the energy to the opposite side of the disc near its periphery. With the use of two fiber optic bundles 52 and 54, as illustrated in FIG. 4, the number of light actuated switch members 38 will be reduced accordingly. Referring to FIG. 3 and using the disc 56 of FIG. 4 every other light actuated switching member 38 in FIG. 3 may be removed. The angle N between each fiber optic bundle 52 and 54 is equal to an odd multiple of the quotient found by dividing 360° by the number of injector actuated circuits in the fuel injector control system 44 required for the particular internal combustion engine 16. For example in an eight cylinder engine using two fiber optic bundles the angle N may be any odd multiple of the angle 45°. As illustrated in FIG. 4 the angle N is approximately 135° and the angular spacing of the light actuated switching members is 90°. If such a configuration was used in a six cylinder engine the angle N would be 60° and the angular spacing of the light actuated switching members 38 would be 120°.
Referring to FIG. 5 there is illustrated a modification for mounting at least two sources of radiant energy 58 and 60 in a redundant configuration. As illustrated in FIG. 5 by the use of two radiant energy sources this provides an insurance of one source if the other source fails. It is important in the mounting of the two sources 58 and 60 within their own housing 62 that all the radiant energy emitted by either source is directed toward the receiving surface 32 of the fiber optic bundle 30 on the disc 22. Thus as illustrated in FIG. 5 each source 58 and 60 is mounted to a surface which is slightly inclined toward the projected axis of the shaft 14.
Referring to FIG. 6, there is illustrated an electrical circuit 64 for controlling the dual radiant energy sources 58 and 60 of FIG. 5. The circuit of FIG. 5 is arranged so that when power is applied to the circuit 64 the first radiant energy source 58 is energized. The transistor Q1 66 is turned on driving its collector near ground. With the collector of the transistor Q1 66 near ground the second radiant energy source 60 is not energized. When the first radiant energy source 58 burns out or is extinguished, the voltage at the junction 68 of the radiant energy source 58 and its series resistor 70 rises toward the source voltage. This increasing voltage signal is reflected across the capacitor 72 to the base of the transistor Q2 74 driving it into conduction. When the transistor Q2 74 is turned on, its collector approaches ground, grounding the base of the transistor Q1 66, turning it off. When the transistor Q1 66 is driven out of conduction the second radiant energy source 60 is immediately energized through its series resistor 76 from the power source. Subsequent turning on of the transistor Q2 74, the source of power is supplied through the two resistors 76 and 78 in series with the base of the transistor Q2 74 thereby causing the second source of radiant energy 60 to be energized.
There is thus shown and described a light actuated sequential switching mechanism for use in a fuel injection system. The mechanism is used to sequentially energize fuel injectors in the system in synchronism with the demand of the internal combustion engine. The mechanism thus illustrated and described is particularly applicable to individual injector actuation, however the mechanism may be modified for multiple group actuation by the proper positioning and controlling of the light actuated switching members.