Engine timing meter

Claim 2

Method of measuring ignition timing of an internal combustion engine having a crankshaft and an even number of cylinders comprising steps of: generating in each revolution of said crankshaft a reference signal which coincides in time with the same specified angular position of said crankshaft, whereby upon successive revolutions of said shaft to generate a train of said reference signals which are spaced apart in time proportional to the rotational velocity of said shaft, generating in alternate ones of said revolutions a first series of ignition signals each of which substantially coincides in time with an ignition pulse supplied to a first of a pair of said cylinders which fire 360* apart, generating in intervening ones of said revolutions a second series of ignition signals each of which substantially coincides in time with an ignition pulse supplied to the second of said cylinders, generating an electric wave train by shifting between a first predetermined voltage value and a second predetermined voltage value in response to, respectively, said reference signals and said ignition signals, and measuring the average DC level between said voltage values.

Claim 3

Method according to claim 1 comprising the steps of generating said first series of ignition signals from ignition pulse energy flowing to said first cylinder, and generating said second series of ignition signals from ignition pulse energy flowing to said second cylinder.

Claim 4

Method according to claim 1 comprising the steps of generating both said first series and said second series of ignition signals from a common source in the ignition system of said engine, and subsequently separating ignition signals of said first series from ignition signals of said second series.

Claim 5

Method according to claim 1 including the further steps of measuring the frequency of said rectangular wave train and indicating said frequency in terms of revolutions per minute of said engine.

Claim 6

Method according to claim 1 in which said wave train is rectangular.

Claim 7

Apparatus for measuring ignition timing of an internal combustion engine having a crankshaft and a plurality of cylinders, comprising set-reset electric wave output means having first and second inpUt signal terminals for the application of, respectively, a set pulse signal and a reset pulse signal, and first and second output voltage terminals which during operation are each established at one or the other, respectively, of two different predetermined voltage values, such that the voltage values at said output terminals can be either in a first state or in a second state reversed relative one to the other, first input means coupled to said first input signal terminal for applying thereto a reference pulse coinciding in time with a specified angular position of said crankshaft, second input means coupled to said second input signal terminal for applying thereto test pulses coinciding in time alternately with the ignition pulses supplied, respectively, to two selected cylinders which fire 360* apart, whereby during operation of said engine to apply to said apparatus a train of said reference pulses interleaved one-by-one with a train of said test pulses corresponding alternately to one and then the other of said cylinders, thereby to cause said predetermined voltage values to alternate between said first state and said second state in synchronism with said pulses such that with respect to time the voltage between said output voltage terminals becomes an electric wave train alternating between said predetermined voltage values, and means coupled effectively across said output voltage terminals to measure the DC level between said voltage values of said wave train over several cycles thereof.

Claim 8

Apparatus for measuring ignition timing of an internal combustion engine having a crankshaft and a plurality of cylinders, comprising set-reset electric wave output means having first and second inpUt signal terminals for the application of, respectively, a set pulse signal and a reset pulse signal, and first and second output voltage terminals which during operation are each established at one or the other, respectively, of two different predetermined voltage values, such that the voltage values at said output terminals can be either in a first state or in a second state reversed relative one to the other, first input means coupled to said first input signal terminal for applying thereto a reference pulse coinciding in time with a specified angular position of said crankshaft, second input means coupled to said second input signal terminal for applying thereto test pulses coinciding in time alternately with the ignition pulses supplied, respectively, to two selected cylinders which fire 360* apart, whereby during operation of said engine to apply to said apparatus a train of said reference pulses interleaved one-by-one with a train of said test pulses corresponding alternately to one and then the other of said cylinders, thereby to cause said predetermined voltage values to alternate between said first state and said second state in synchronism with said pulses such that with respect to time the voltage between said output voltage terminals becomes an electric wave train alternating between said predetermined voltage values, and means coupled effectively across said output voltage terminals to measure the DC level between said voltage values of said wave train over several cycles thereof.

Claim 9

Apparatus according to claim 6 in which said means coupled to said second input signal terminal comprises a separate coupling to the ignition line of each of said two selected cylinders.

Claim 10

Apparatus according to claim 6 for measuring ignition timing of an internal combustion engine having an ignition coil, a crankshaft and a plurality of cylinders in which said means coupled to said second input signal terminal comprises a connection from the battery side of said ignition coil of said engine to said second input signal terminal, for deriving from the battery connection to said coil a test pulse coinciding in time with the ignition pulse applied to each cylinder of said engine, switch means for controlling passage of said test pulses to said second input signal terminal, gate means controlling said switch means to pass said test pulses coinciding with the ignition pulses of said two cylinders, and means to synchronize said gate means with said reference pulses.

Claim 11

Apparatus according to claim 8 including voltage generating means comprising a storage capacitor connected in series with a diode from the battery side of said coil to the remaining side of the battery, means providing a substantially constant-current discharge path across said capacitor, and means in said path to provide a source of substantially constant voltage.

Claim 12

Apparatus for measuring ignition timing of an internal combustion engine having a crankshaft and a plurality of cylinders, comprising set-reset electric wave output means having first and second input signal terminals for the application of, respectively, a set pulse signal and a reset pulse signal, and first and second output voltage terminals which during operation are each established at one or the other, respectively, of two different predetermined voltage values, such that the voltage values at said output terminals can be either in a first state or in a second state reversed relative one to the other, first input means coupled to said first input signal terminal for applying thereto a reference pulse coinciding in time with a specified angular position of said crankshaft, second input means coupled to said second input signal terminal for applying thereto a test pulse coinciding in time with the ignition pulse supplied to a selected one of said cylinders, whereby during operation of said engine to apply to said apparatus a train of said reference pulses interleaved with a train of said test pulses, thereby to cause said predeTermined voltage values to alternate between said first state and said second state in synchronism with said pulses such that with respect to time the voltage between said output voltage terminals becomes an electric wave train alternating between said predetermined voltage values, and means coupled effectively across said output voltage terminals to measure the DC level between said voltage values of said wave train over several cycles thereof, said apparatus including calibrating circuit means having an input connection to said first input means and first and second paths in shunt from said input connection to respective first and second calibrating terminals, first switch means arranged to transfer said first input signal terminal from said first input means to said first calibrating terminal, second switch means arranged to transfer said second input signal terminal from said second input means to said second calibrating terminal, said calibrating circuit means being arranged to apply said reference pulses alternately to said first and second input signal terminals whereby to cause said predetermined voltage values to alternate between said first state and said second state in synchronism with only said reference pulses and thereby provide a prescribed value of said DC level.

Claim 13

Apparatus for measuring ignition timing of an internal combustion engine having a crankshaft and a plurality of cylinders, comprising set-reset electric wave output means having first and second input signal terminals for the application of, respectively, a set pulse signal and a reset pulse signal, and first and second output voltage terminals which during operation are each established at one or the other, respectively, of two different predetermined voltage values, such that the voltage values at said output terminals can be either in a first state or in a second state reversed relative one to the other, first input means coupled to said first input signal terminal for applying thereto a reference pulse coinciding in time with a specified angular position of said crankshaft, second input means coupled to said second input signal terminal for applying thereto a test pulse coinciding in time with the ignition pulse supplied to a selected one of said cylinders, whereby during operation of said engine to apply to said apparatus a train of said reference pulses interleaved with a train of said test pulses, thereby to cause said predeTermined voltage values to alternate between said first state and said second state in synchronism with said pulses such that with respect to time the voltage between said output voltage terminals becomes an electric wave train alternating between said predetermined voltage values, and means coupled effectively across said output voltage terminals to measure the DC level between said voltage values of said wave train over several cycles thereof, said apparatus including calibrating circuit means having an input connection to said first input means and first and second paths in shunt from said input connection to respective first and second calibrating terminals, first switch means arranged to transfer said first input signal terminal from said first input means to said first calibrating terminal, second switch means arranged to transfer said second input signal terminal from said second input means to said second calibrating terminal, said calibrating circuit means being arranged to apply said reference pulses alternately to said first and second input signal terminals whereby to cause said predetermined voltage values to alternate between said first state and said second state in synchronism with only said reference pulses and thereby provide a prescribed value of said DC level.

Claim 14

Apparatus for measuring ignition timing of an internal combustion engine having a crankshaft and a plurality of cylinders, a primary source of electric energy and distributor means arranged to supply ignition energy from said source to each of said cylinders, said apparatus comprising set-reset electric wave output means having first and second input signal terminals for the application of, respectively, a set pulse signal and a reset pulse signal, and first and second output voltage terminals which during operation are each established at one or the other, respectively, of two different predetermined voltage values, such that the voltage values at said output terminals can be either in a first state or in a second state reversed relative one to the other, first input means coupled to said first input signal terminal for applying thereto a reference pulse coinciding in time with a specified angular position of said crankshaft, second input means coupled to said second input signal terminal for applying thereto a test pulse coinciding in time with the ignition pulse supplied to a selected one of said cylinders, whereby during operation of said engine to apply to said apparatus a train of said reference pulses interleaved with a train of said test pulses, thereby to cause said predetermined voltage values to alternate between said first state and said second state in synchronism with said pulses such that with respect to time the voltage between said output voltage terminals becomes an electric wave train alternating between said predetermined voltage values, means coupled effectively across said output voltage terminals to measure the DC level between said voltage values of said wave train over several cycles thereof, and voltage generating means for supplying power to said apparatus, comprising a diode, a storage capacitor connected in series with said diode to said distributor for storing bursts of electric energy in said capacitor in synchronism with firing of said cylinders, means providing a substantially constant-current discharge path across said capacitor, and means in said path to provide a source of substantially constant voltage for said apparatus.

Claim 15

Apparatus for measuring ignition timing of an internal combustion engine having a crankshaft and a plurality of cylinders, a primary source of electric energy and distributor means arranged to supply ignition energy from said source to each of said cylinders, said apparatus comprising set-reset electric wave output means having first and second input signal terminals for the application of, respectively, a set pulse signal and a reset pulse signal, and first and second output voltage terminals which during operation are each established at one or the other, respectively, of two different predetermined voltage values, such that the voltage values at said output terminals can be either in a first state or in a second state reversed relative one to the other, first input means coupled to said first input signal terminal for applying thereto a reference pulse coinciding in time with a specified angular position of said crankshaft, second input means coupled to said second input signal terminal for applying thereto a test pulse coinciding in time with the ignition pulse supplied to a selected one of said cylinders, whereby during operation of said engine to apply to said apparatus a train of said reference pulses interleaved with a train of said test pulses, thereby to cause said predetermined voltage values to alternate between said first state and said second state in synchronism with said pulses such that with respect to time the voltage between said output voltage terminals becomes an electric wave train alternating between said predetermined voltage values, means coupled effectively across said output voltage terminals to measure the DC level between said voltage values of said wave train over several cycles thereof, and voltage generating means for supplying power to said apparatus, comprising a diode, a storage capacitor connected in series with said diode to said distributor for storing bursts of electric energy in said capacitor in synchronism with firing of said cylinders, means providing a substantially constant-current discharge path across said capacitor, and means in said path to provide a source of substantially constant voltage for said apparatus.