Abstract An electric cranking motor automatic disconnect and lockout circuit. The normally open contacts of a cranking motor solenoidoperated switch, having the operating coil thereof connected across a source of direct current potential through the normally open contacts of a first relay, are connected in series with the cranking motor across a source of direct current potential. Upon the closure of an electric switch, the source of direct current potential energizes the operating coil of the first relay, through the electric switch and the normally closed contacts of a second relay in series, to close the associated normally open contacts thereof which establish an energizing circuit for the operating coil of the solenoid-operated switch. At least a portion of the output potential of an electric generator driven by the cranked engine is applied across the gate-cathode electrodes of a silicon-controlled rectifier, the anode-cathode electrodes of which are connected in series with another contact of the electric switch and the operating coil of the second relay across the source of direct current potential. When the generator output potential is of sufficient magnitude to produce gatecathode current through the silicon-controlled rectifier, the resulting anode-cathode current flow therethrough establishes an energizing circuit for the operating coil of the second relay to open the associated normally closed contacts, thereby interrupting the energizing circuit for the operating coil of the first relay to permit the associated normally open contacts to open which interrupt the energizing circuit for the operating coil of the solenoid operated switch. The silicon-controlled rectifier is maintained conductive while the electric switch is closed to the anode-cathode electrodes thereof, consequently, the operating coil of the second relay remains energized thereby preventing a reengagement of the cranking motor while the engine is in the running mode.
Inventors
👤 Donald L Cummins
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-23 23:53
CPC Classifications
F; F02; F02N; F02N11/00; F02N11/08; F02N11/0848
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
242 words
An electric cranking motor automatic disconnect and lockout circuit comprising in combination with a source of direct current potential, a cranking motor connected thereAcross through the normally open contacts of a solenoid-operated switch having at least one operating coil, an engine to be cranked thereby and an electrical generator driven by the engine: a first relay having an operating coil and two normally open contacts; means for connecting said operating coil of said solenoidoperated switch across said source of direct current potential through said normally open contacts of said first relay; a second relay having an operating coil and two normally closed contacts; an electric switch having a movable contact and at least two stationary contacts; means for connecting said operating coil of said first relay across said source of direct current potential through said normally closed contacts of said second relay and said movable contact and one of said stationary contacts of said electric switch; a silicon controlled rectifier having an anode, a cathode and a gate electrode; means for connecting said operating coil of said second relay across said source of direct current potential through said movable contact and another one of said stationary contacts of said electric switch and said anode-cathode electrodes of said silicon-controlled rectifier; and means for applying at least a portion of the output potential of said generator across said gate-cathode electrodes of said silicon-controlled rectifier in a polarity relationship to produce gate-cathode current flow therethrough.
Claim 2
Dependent Claim
242 words
An electric cranking motor automatic disconnect and lockout circuit comprising in combination with a source of direct current potential, a cranking motor connected thereAcross through the normally open contacts of a solenoid-operated switch having at least one operating coil, an engine to be cranked thereby and an electrical generator driven by the engine: a first relay having an operating coil and two normally open contacts; means for connecting said operating coil of said solenoidoperated switch across said source of direct current potential through said normally open contacts of said first relay; a second relay having an operating coil and two normally closed contacts; an electric switch having a movable contact and at least two stationary contacts; means for connecting said operating coil of said first relay across said source of direct current potential through said normally closed contacts of said second relay and said movable contact and one of said stationary contacts of said electric switch; a silicon controlled rectifier having an anode, a cathode and a gate electrode; means for connecting said operating coil of said second relay across said source of direct current potential through said movable contact and another one of said stationary contacts of said electric switch and said anode-cathode electrodes of said silicon-controlled rectifier; and means for applying at least a portion of the output potential of said generator across said gate-cathode electrodes of said silicon-controlled rectifier in a polarity relationship to produce gate-cathode current flow therethrough.
Claim 3
Dependent Claim
260 words
An electric cranking motor automatic disconnect and lockout circuit comprising in combination with a source of direct current potential, a cranking motor connected thereacross through the normally open contacts of a solenoid-operated switch having at least one operating coil, an engine to be cranked thereby and a three-phase alternator driven by the engine: a first relay having an operating coil and two normally open contacts; means for connecting said operating coil of said solenoid-operated switch across said source of direct current potential through said normally open contacts of said first relay; a second relay having an operating coil and two normally closed contacts; an electric switch having a movable contact and at least two stationary contacts; means for connecting said operating coil of said first relay across said source of direct current potential through said normally closed contacts of said second relay and said movable contact and one of said stationary contacts of said electric switch; a silicon controlled rectifier having an anode, a cathode and a gate electrode; means for connecting said operating coil of said second relay across said source of direct current potential through said movable contact and another one of said stationary contacts of said electric switch and said anode-cathode electrodes of said silicon-controlled rectifier; a three-phase diode bridge-type rectifier circuit comprising the parallel combination of three pairs of series connected diodes for rectifying the output of said three-phase alternator; and means for connecting said gate electrode of said silicon-controlled rectifier to a junction between any two of said series connected diodes of said rectifier circuit.
Claim 4
Dependent Claim
260 words
An electric cranking motor automatic disconnect and lockout circuit comprising in combination with a source of direct current potential, a cranking motor connected thereacross through the normally open contacts of a solenoid-operated switch having at least one operating coil, an engine to be cranked thereby and a three-phase alternator driven by the engine: a first relay having an operating coil and two normally open contacts; means for connecting said operating coil of said solenoid-operated switch across said source of direct current potential through said normally open contacts of said first relay; a second relay having an operating coil and two normally closed contacts; an electric switch having a movable contact and at least two stationary contacts; means for connecting said operating coil of said first relay across said source of direct current potential through said normally closed contacts of said second relay and said movable contact and one of said stationary contacts of said electric switch; a silicon controlled rectifier having an anode, a cathode and a gate electrode; means for connecting said operating coil of said second relay across said source of direct current potential through said movable contact and another one of said stationary contacts of said electric switch and said anode-cathode electrodes of said silicon-controlled rectifier; a three-phase diode bridge-type rectifier circuit comprising the parallel combination of three pairs of series connected diodes for rectifying the output of said three-phase alternator; and means for connecting said gate electrode of said silicon-controlled rectifier to a junction between any two of said series connected diodes of said rectifier circuit.