Apparatus for controlling the speed and phase of engines

Claim 2

In combination: a master engine, a slave engine, a variable pitch propeller having pitch adjusting means and driven by said slave engine, a spring loaded governor driven by said slave engine and controlling said pitch adjusting means and operable to cause the propeller pitch to vary directly with variations in speed of said slave engine, adjustable biasing means operatively associated with said governor and energizable for adjusting the load on said governor to adjust the response of said governor to engine speed, means establiShing a speed standard comprising an element actuated by said master engine, comparing means for comparing the speed of said slave engine with said speed standard and operable to develop a signal in response to a difference between said speeds, a source of energy for said biasing means, and control means operable in response to said signal for controlling the supply of energy from said source to said biasing means to adjust the bias on said governor and in a direction to reduce said difference, said comparing means comprises photosensitive means and lamp means for illuminating said photosensitive means and a rotary member between said lamp means and said photosensitive means having one rotated position wherein the light from said lamp means is blocked off from said photosensitive means, said element driven by said master engine being operable for actuating one of said rotary member and lamp means while said slave engine actuates the other thereof, and illumination of said photosensitive means providing said signal for actuating said control means.

Claim 3

The combination according to claim 1 in which said rotary member is a disc having an opaque portion which is disposed between said lamp means and photosensitive means in said one rotated position of said disc, said lamp means when actuated being momentarily energized in a predetermined rotated position of the actuating engine therefor to provide stroboscopic light source means.

Claim 4

The combination according to claim 2 in which said photosensitive means comprises a pair of photosensitive elements each operable to provide a signal for actuation of said control means for adjustment of the supply of energy from said source to said biasing means in a respective direction when illuminated, said disc in said one rotated position thereof blocking off the light from said lamp means to both of said photosensitive elements and when displaced in respective directions from said one rotated position exposing respective ones of said photosensitive elements to the light from said lamp means.

Claim 5

The combination according to claim 3 in which said biasing means is electrically operable and the said source includes a source of electrical energy, said control means comprising first and second control circuits each operable when completed to provide for adjustment of the supply of energy from said source to said biasing means in a respective direction, each photosensitive element being connected in controlling relation to a respective one of said circuits.

Claim 6

The combination according to claim 4 which includes means responsive to the completion of either of said first and second control circuits for preventing the completion of the other thereof.

Claim 7

The combination according to claim 4 in which said biasing means is in the form of a coil operable when energized to establish a magnetic field, said governor including centrifugally operable means comprising at least one magnetic part and movable in response to changes in engine speed, said coil being so mounted as to cause the field thereupon to act on said magnetic part of said governor and in the direction of movement thereof whereby the total load on the governor which controls the governor response to engine speed includes the spring load thereon and the magnetic load thereon, a change in the supply of energy to said coil changing the position of the governor for a given speed of the slave engine.

Claim 8

The combination according to claim 6 in which said governor comprises a reciprocable valve member and said magnetic part is integral therewith.

Claim 9

The combination according to claim 6 in which said governor comprises flyball members, said flyball members being magnetic and forming the magnetic part of said governor acted on by the field of said coil.

Claim 10

The combination according to claim 4 which includes adjustable current controlling means operable for controlling the supply of energy from said source to said biasing means, a reversible motor connected to said current contRolling means for adjustment thereof in opposite directions, said first and second control currents being connected in circuit with said motor and each controlling the energization of said motor in a respective direction.

Claim 11

The combination according to claim 9 in which said current controlling means includes a rheostat, said motor being connected in adjusting relation to said rheostat.

Claim 12

The combination according to claim 1 in which said biasing means is a solenoid coil and said source of energy comprises a source of direct current, a current controlling transistor having the collector-emitter path thereof in series with said coil across said source, biasing resistor means connected across said source and to the base of current controlling transistor, said control means including an adjustable element associated with said resistor means movable for varying the conductivity of said current controlling transistor, a reversible motor connected to said element for adjustment thereof, and energizing circuit means connected to said motor and under the control of said signals from said comparing means.

Claim 13

The combination according to claim 11 in which said energizing circuit means includes first and second transistorized circuits connected to said motor and each effective for causing rotation of the movement of the motor in a respective direction, said first circuit becoming effective in response to a said signal from said comparing means resulting from a leading condition of said slave motor and said second circuit becoming effective in response to a said signal resulting from a trailing condition of said slave motor, each of said first and second circuits having a control terminal to receive the respective signal from said comparing means.

Claim 14

The combination according to claim 12 which includes a transistor for each control terminal having the collector-emitter path thereof connected between ground and the respective control terminal, each transistor having the base thereof connected to the other control terminal whereby a signal supplied to one control terminal will prevent the supply of a signal to the other control terminal.

Claim 15

The combination according to claim 12, in which said resistor means connected to the base of said current controlling means comprises a pair of resistors connected in series across said source and having the juncture thereof connected to the base of said current controlling transistor, a further transistor having the collector-emitter path thereof connected across each of said pair of resistors, and the base of each further resistor being connected to a point in a respective one of said first and second circuits to receive a biasing signal therefrom when the respective circuit is actuated by a signal from said comparing means.

Claim 16

The combination according to claim 13, which includes a second pair of resistors connected in series, switch means selectively operable for interrupting the connection between the bases of each of said further transistors and the respective said first and second circuits while simultaneously connecting said second pairs of resistors across said source, and means connected between the juncture of said coil with the collector-emitter path of said current controlling transistor and the juncture of said second pair of resistors and responsive to the voltage between said junctures to make the one of said first and second circuits effective which will lead to adjustment of said element in a direction to reduce said voltage.

Claim 17

The combination according to claim 15 in which said last mentioned means comprises a pair of transistors each having the emitter connected to a respective one of said junctures and the base connected to the other thereof whereby each of the transistors goes conductive in response to a voltage between said junctures of a respective polarity, the collectors of the said transistors being connected to said first and second circuits to supply actuating signals thereto when the respectivE transistor goes conductive.

Claim 18

The combination according to claim 1 in which said means establishing a speed standard also includes means for establishing a phase standard, said comparing means also comparing the phase of said slave engine with that of said master engine and developing a said signal in conformity with measured differences in phase.

Claim 19

In a twin-engine aircraft having a master engine and a slave engine and a constant speed propeller driven by each engine and each propeller including a fluid motor to adjust the pitch thereof; means for synchronizing the speed of said engines, comprising: a speed sensing fluid governor driven by each said engine, each said governor incorporating a pilot valve regulating the flow of fluid to the respective said fluid motor for maintaining the respective propeller at the proper pitch for a prescribed rotational speed of the engine connected thereto, each said pilot valve being resiliently biased toward pitch reducing position and each governor urging the respective pilot valve toward pitch increasing position as the speed of the pertaining engine increases, said governor driven by said slave engine incorporating unidirectionally acting magnetic means operatively associated with said pilot valve and adapted to develop a unidirectional bias thereon, said magnetic means comprising magnetic coil means and magnet means unidirectionally influenced by the field of said magnetic coil means, one of said magnet means and magnet coil means being connected to the said pilot valve to move therewith and the other thereof being stationarily mounted, an energizing circuit connected to said magnetic coil means to supply energy thereto and including a source of electrical energy, speed comparing means comprising an element actuated by each engine and operable for comparing the rotational speed of said master engine with that of said slave engine, said speed comparing means developing signals which vary in conformity with the relative rotational speed of said engines, and means operatively associated with said energizing circuit and connected to receive said signals and operable for varying the degree of energization of said magnetic coil means by said energizing circuit in response to variations in said signals, variations in the degree of energization of said magnetic coil means adjusting the bias exerted by said magnetic means on said pilot valve of the slave engine governor and in a direction to tend to bring said speed of said slave engine into synchronism with that of said master engine.

Claim 20

In a twin-engine aircraft having a master engine and a slave engine and a constant speed propeller driven by each engine and each propeller including a fluid motor to adjust the pitch thereof; means for synchronizing the speed of said engines, comprising: a speed sensing fluid governor driven by each said engine, each said governor incorporating a pilot valve regulating the flow of fluid to the respective said fluid motor for maintaining the respective propeller at the proper pitch for a prescribed rotational speed of the engine connected thereto, each said pilot valve being resiliently biased toward pitch reducing position and each governor urging the respective pilot valve toward pitch increasing position as the speed of the pertaining engine increases, said governor driven by said slave engine incorporating unidirectionally acting magnetic means operatively associated with said pilot valve and adapted to develop a unidirectional bias thereon, said magnetic means comprising magnetic coil means and magnet means unidirectionally influenced by the field of said magnetic coil means, one of said magnet means and magnet coil means being connected to the said pilot valve to move therewith and the other thereof being stationarily mounted, an energizing circuit connected to said magnetic coil means to supply energy thereto and including a source of electrical energy, speed comparing means comprising an element actuated by each engine and operable for comparing the rotational speed of said master engine with that of said slave engine, said speed comparing means developing signals which vary in conformity with the relative rotational speed of said engines, and means operatively associated with said energizing circuit and connected to receive said signals and operable for varying the degree of energization of said magnetic coil means by said energizing circuit in response to variations in said signals, variations in the degree of energization of said magnetic coil means adjusting the bias exerted by said magnetic means on said pilot valve of the slave engine governor and in a direction to tend to bring said speed of said slave engine into synchronism with that of said master engine.

Claim 21

The combination according to claim 18 in which said comparing means comprises a rotating magnet driven by said master engine and a stationary coil adjacent to and cooperating with said magnet to emit electrical pulses in unison with the movement of said magnet past said coil, amplifying means to amplify said electrical pulses, said comparing means also comprising a rotatable shaft driven by said slave engine, a pair of fixed photosensitive elements angularly spaced less than 180* about said shaft, a pair of fixed lamps facing said photosensitive elements, means for momentarily illuminating said lamps by the amplified electrical pulses from said amplifying means, a disc located between said lamps and said photosensitive means and mounted for rotation with said shaft, said disc being opaque over a sufficient portion of its surface to block off the light from both lamps to said photosensitive elements when in the null position, said disc exposing one photosensitive element to a light pulse when angularly displaced slightly in one direction from said null position and exposing the other photosensitive element to a light pulse when angularly displaced slightly in the other direction from said null position, each photosensitive element emitting an electrical signal when illuminated, means for amplifying said electrical signals, one said photosensitive elements emitting electrical signals when exposed to light for the purpose of energizing said magnetIc coil means in a manner to bias said pilot valve in one direction, the other said photosensitive element emitting electrical signals when exposed to light for the purpose of energizing said magnetic coil means in a manner to bias said pilot valve in the opposite direction, thereby tending to bring the speed of said slave engine into synchronization with said master engine when said opaque portion of said disc is out of the null position at the instant when the light pulses occur.

Claim 22

The combination according to claim 19 wherein said rotating magnet is driven by said slave engine and said rotating shaft is driven by said master engine.

Claim 23

The combination according to claim 19, including means for adjusting the angular position of said photosensitive elements, together with the corresponding lamps, about said rotatable shaft.

Claim 24

The combination according to claim 19, including means for adjusting the angular position of said coil about the shaft of said rotating magnet.

Claim 25

The combination according to claim 19, including means for automatically controlling the current supplied to said magnetic coils according to a prescribed schedule when said disc is not in the null position.

Claim 26

In combination according to claim 19, including means for energizing said magnetic coils with a constant current in one direction to provide a reference bias on said pilot valve, said means including means for automatically changing the degree of bias when said disc is displaced from the null position a predetermined amount.

Claim 27

In combination according to claim 24 in which said means for automatically changing the degree of bias includes a motor driven potentiometer for the purpose of changing the current supplied to said magnetic coil.

Claim 28

In combination according to claim 19 including means for blocking out the signal emitted by the second photosensitive element which becomes uncovered by the opaque portion of said disc after the said opaque portion becomes displaced from said null position, in order that the signal from the first photosensitive element which becomes uncovered can act without opposition from said second photosensitive element to energize said coil in a direction to correct the out of synchronous condition when the rotational speed of said slave engine is above or below the speed of said master engine by a prescribed amount.

Claim 29

In a twin-engine aircraft having a master engine and a slave engine and a constant speed propeller driven by each engine and each propeller including a fluid motor to adjust the pitch thereof; means for synchronizing the speed of said engines, comprising: a speed sensing fluid governor driven by each said engine, each said governor incorporating a pilot valve regulating the flow of fluid to the respective said fluid motor for maintaining the respective propeller at the proper pitch for a prescribed rotational speed of the engine connected thereto, each said pilot valve being resiliently biased toward pitch reducing position and each governor urging the respective pilot valve toward pitch increasing position as the speed of the pertaining engine increases, said governor driven by said slave engine incorporating unidirectionally acting magnetic means operatively associated with said pilot valve and adapted to develop a unidirectional bias thereon, said magnetic means comprising magnetic coil means and magnet means unidirectionally influenced by the field of said magnetic coil means, one of said magnet means and magnet coil means being connected to the said pilot valve to move therewith and the other thereof being stationarily mounted, an energizing circuit connected to said magnetic coil means to supply energy thereto and including a source of electrical energy, comparing means comprising an element actuated by each engine and operable for comparing the angular position of the propeller driven by said slave engine with the angular position of the propeller driven by said master engine, said comparing means developing first signaLs when said propeller driven by the slave engine leads a predetermined position relative to the propeller driven by the master engine and second signals when the propeller driven by the slave engine trails said predetermined position relative to the propeller driven by the master engine, and means operatively associated with said energizing circuit and connected to receive said first and second signals and operable for increasing the degree of energization of said magnetic coil means in response to one of said signals and to decrease the degree of energization of said magnetic coil means in response to the other of said signals, the said changes in the degree of energization of said magnetic coil means adjusting the bias on said pilot valve of the slave engine governor in a direction to tend to bring said relative angular positions of said propellers into a desired predetermined relationship.

Claim 30

In a twin-engine aircraft having a master engine and a slave engine and a constant speed propeller driven by each engine and each propeller including a fluid motor to adjust the pitch thereof; means for synchronizing the speed of said engines, comprising: a speed sensing fluid governor driven by each said engine, each said governor incorporating a pilot valve regulating the flow of fluid to the respective said fluid motor for maintaining the respective propeller at the proper pitch for a prescribed rotational speed of the engine connected thereto, each said pilot valve being resiliently biased toward pitch reducing position and each governor urging the respective pilot valve toward pitch increasing position as the speed of the pertaining engine increases, said governor driven by said slave engine incorporating unidirectionally acting magnetic means operatively associated with said pilot valve and adapted to develop a unidirectional bias thereon, said magnetic means comprising magnetic coil means and magnet means unidirectionally influenced by the field of said magnetic coil means, one of said magnet means and magnet coil means being connected to the said pilot valve to move therewith and the other thereof being stationarily mounted, an energizing circuit connected to said magnetic coil means to supply energy thereto and including a source of electrical energy, comparing means comprising an element actuated by each engine and operable for comparing the angular position of the propeller driven by said slave engine with the angular position of the propeller driven by said master engine, said comparing means developing first signaLs when said propeller driven by the slave engine leads a predetermined position relative to the propeller driven by the master engine and second signals when the propeller driven by the slave engine trails said predetermined position relative to the propeller driven by the master engine, and means operatively associated with said energizing circuit and connected to receive said first and second signals and operable for increasing the degree of energization of said magnetic coil means in response to one of said signals and to decrease the degree of energization of said magnetic coil means in response to the other of said signals, the said changes in the degree of energization of said magnetic coil means adjusting the bias on said pilot valve of the slave engine governor in a direction to tend to bring said relative angular positions of said propellers into a desired predetermined relationship.

Claim 31

The combination according to claim 27 in which said comparing means comprises a rotating magnet driven by said master engine and a stationary coil adjacent to and cooperating with said magnet to emit electrical pulses in unison with the movement of said magnet past said coil, amplifying means to amplify said electrical pulses, said comparing means also comprising a rotatable shaft driven by said slave engine, a pair of fixed photosensitive elements angularly spaced less than 180* about said shaft, a pair of fixed lamps facing said photosensitive elements, means for momentarily illuminating said lamps by the amplified electrical pulses from said amplifying means, a disc located between said lamps and said photosensitive means and mounted for rotation with said shaft, said disc being opaque over a sufficient portion of its surface to block off the light from both lamps to said photosensitive elements when in the null position, said disc exposing one photosensitive element to a light pulse when angularly displaced slightly in one direction from said null position and exposing the other photosensitive element to a light pulse when angularly displaced slightly in the other direction from said null position, each photosensitive element emitting an electrical signal when illuminated, means for amplifying said electrical signals, one said photosensitive elements emitting electrical signals when exposed to light for the purpose of energizing said magnetic coil means in a manner to bias said pilot valve in one direction, the other said photosensitive element emitting electrical signals when exposed to light for the purpose of energizing said magnetic coil means in a manner to bias said pilot valve in the opposite direction, thereby tending to bring the speed of said slave engine into synchronization with said master engine when said opaque portion of said disc is out of the null position at the instant when the light pulses occur.