Reversing control system for electrically powered vehicles

Claim 2

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. means for supplying excitation to said generator shunt field; d. means mechanically coupling said generator to said power source; e. a direct current electric drive motor having a shunt field and a series field; f. conductor means operably connecting output terminals of said generator with input terminals of said motor; g. means for supplying excitation to said motor shunt field; h. means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied from said generator to said motor; i. means connected with said motor excitation means for signalling the magnitude of excitation to be supplied to said motor shunt field; j. reversing switch means for effecting reversal of said motor series field connections immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; l. means for deriving a voltage signal which is a function of the armature voltage of said motor and utilizing said signal to effect actuation of said actuation means when the speed of said motor decreases to or is below a predetermined speed.

Claim 3

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. means for supplying excitation to said generator shunt field; d. means mechanically coupling said generator to said power source; e. a plurality of direct current electric wheel drive motors each having a shunt field and a series field; f. conductor means operably connecting output terminals of said generator with input terminals of said wheel motors; g. means for supplying excitation to said wheel motor shunt fields; h. means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied to said wheel motors; i. Means connected with said motor excitation means for signalling the magnitude of excitation to be supplied to said wheel motor shunt fields; j. reversing switch means for effecting reversal of said respective motor series field connections immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; l. means for deriving a voltage signal which is a function of the armature voltage of one of said motors and utilizing said signal to effect actuation of said actuation means when the speed of said motor decreases to or is below a predetermined speed.

Claim 4

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. means for supplying excitation to said generator shunt field; d. means mechanically coupling said generator to said power source; e. a plurality of direct current electric wheel drive motors each having a shunt field and a series field; f. conductor means operably connecting output terminals of said generator with input terminals of said wheel motors; g. means for supplying excitation to said wheel motor shunt fields; h. means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied to said wheel motors; i. Means connected with said motor excitation means for signalling the magnitude of excitation to be supplied to said wheel motor shunt fields; j. reversing switch means for effecting reversal of said respective motor series field connections immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; l. means for deriving a voltage signal which is a function of the armature voltage of one of said motors and utilizing said signal to effect actuation of said actuation means when the speed of said motor decreases to or is below a predetermined speed.

Claim 5

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. means for supplying excitation to said generator shunt field; d. means mechanically coupling said generator to said power source; e. a plurality of direct current electric wheel drive motors each having a shunt field and a series field; f. conductor means operably connecting output terminals of said generator with input terminals of said wheel motors; g. means for supplying excitation to said wheel motor shunt fields; h. means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied to said wheel motors; i. means connected with said motor excitation means for signalling the magnitude of excitation to be supplied to said wheel motor shunt fields; j. reversing switch means for effecting reversal of said motor series field connection immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; l. means connected with at least two wheel motors, one on each side of said vehicle for deriving respective voltage signals which are a function of the armature voltage of respective said last mentioned motors, and utilizing said signals to effect substantially uniform actuation of said actuation means when the speed of a said wheel motor decreases below a predetermined speed, regardless of whether said vehicle is turning in either direction or moving straight ahead.

Claim 6

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. means for supplying excitation to said generator shunt field; d. means mechanically coupling said generator to said power source; e. a plurality of direct current electric wheel drive motors each having a shunt field and a series field; f. conductor means operably connecting output terminals of said generator with input terminals of said wheel motors; g. means for supplying excitation to said wheel motor shunt fields; h. means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied to said wheel motors; i. means connected with said motor excitation means for signalling the magnitude of excitation to be supplied to said wheel motor shunt fields; j. reversing switch means for effecting reversal of said motor series field connection immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; l. means connected with at least two wheel motors, one on each side of said vehicle for deriving respective voltage signals which are a function of the armature voltage of respective said last mentioned motors, and utilizing said signals to effect substantially uniform actuation of said actuation means when the speed of a said wheel motor decreases below a predetermined speed, regardless of whether said vehicle is turning in either direction or moving straight ahead.

Claim 7

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. a first means for supplying excitation to said generator shunt field; d. second means mechanically coupling said generator to said power source; e. a plurality of direct current eletric wheel drive motors each having a shunt field and a series field; f. third means comprising conductor means operably connecting output terminals of said generator with input terminals of said wheel motors; g. fourth means for supplying excitation to said wheel motor shunt fields; h. fifth means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied to said wheel motors; i. sixth means connected for signalling the magnitude of excitation to be supplied to said wheel motor shunt fields; j. reversing switch means for effecting reversal of said respective motor series field connections immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; said actuation means comprising a current sensitive Relay operable when a current greater than a predetermined minimum current flows therethrough; l. means connected with at least two wheel motors, one on each side of said vehicle for deriving respective voltage signals which are a function of the armature voltage of respective said last mentioned motors, and utilizing said signals to effect substantially uniform actuation of said actuating means when the speed of a said wheel motor decreases below a predetermined speed, regardless of whether said vehicle is turning in either direction or moving straight ahead; said speed responsive means comprising: i. a regulated voltage power source that is connectable in bucking relationship with the voltage drop across said wheel motors; said wheel motors being connected in parallel; said regulated voltage power source being adapted to supply a voltage greater than the sum of the voltage drop across a respective wheel motor at said predetermined speed and the voltage drop across said current sensitive relay when said predetermined minimum current flows therethrough; ii. unidirectional conductor means serially connected with said regulated voltage source and said current sensitive relay; iii. bridge means for selecting the slowest turning wheel motor to be serially connected with said regulated voltage power source and said current sensitive relay; said bridge means having four legs, respective sides of said bridge means comprising two adjacent legs having an input terminal that is serially connected with a respective said wheel motor; a first leg of said adjacent legs having a unidirectional conductor means for permitting current to flow in one direction with respect to said input terminal and the second of said adjacent legs having a unidirectional conductor means for permitting current to flow in the other direction with respect to said input terminal; the juncture of said first legs of said sides defining a first output terminal, and the juncture of said second legs of said sides defining a second output terminal; and iv. switch means for maintaining said regulated voltage power source connected in a signalled bucking relationship with said wheel motors regardless of the direction of travel of said vehicle; said switch means comprising a first group of switches responsively connected with said fifth means for serially connecting a first output terminal of said bridge means, said wheel motors, said regulated voltage power source, and said current sensitive relay for current flow in one direction through said wheel motors; and a second group of switches responsively connected with said fifth means for serially connecting a second output terminal of said bridge means, said wheel motors, said regulated voltage power source, and said current sensitive relay for current flow in a second direction through said wheel motors.

Claim 8

A control system for an electrically powered, self-propelled vehicle comprising in combination: a. a prime mover power source; b. a direct current generator having a shunt field; c. a first means for supplying excitation to said generator shunt field; d. second means mechanically coupling said generator to said power source; e. a plurality of direct current eletric wheel drive motors each having a shunt field and a series field; f. third means comprising conductor means operably connecting output terminals of said generator with input terminals of said wheel motors; g. fourth means for supplying excitation to said wheel motor shunt fields; h. fifth means, including a controller, connected with said generator excitation means for signalling direction and speed of said vehicle by signalling the polarity and magnitude of power to be supplied to said wheel motors; i. sixth means connected for signalling the magnitude of excitation to be supplied to said wheel motor shunt fields; j. reversing switch means for effecting reversal of said respective motor series field connections immediately prior to reversal of direction of said vehicle so as to maintain the desired direction of current flow through said series field; k. actuation means connected with said reversing switch means for actuating said reversing switch means; said actuation means comprising a current sensitive Relay operable when a current greater than a predetermined minimum current flows therethrough; l. means connected with at least two wheel motors, one on each side of said vehicle for deriving respective voltage signals which are a function of the armature voltage of respective said last mentioned motors, and utilizing said signals to effect substantially uniform actuation of said actuating means when the speed of a said wheel motor decreases below a predetermined speed, regardless of whether said vehicle is turning in either direction or moving straight ahead; said speed responsive means comprising: i. a regulated voltage power source that is connectable in bucking relationship with the voltage drop across said wheel motors; said wheel motors being connected in parallel; said regulated voltage power source being adapted to supply a voltage greater than the sum of the voltage drop across a respective wheel motor at said predetermined speed and the voltage drop across said current sensitive relay when said predetermined minimum current flows therethrough; ii. unidirectional conductor means serially connected with said regulated voltage source and said current sensitive relay; iii. bridge means for selecting the slowest turning wheel motor to be serially connected with said regulated voltage power source and said current sensitive relay; said bridge means having four legs, respective sides of said bridge means comprising two adjacent legs having an input terminal that is serially connected with a respective said wheel motor; a first leg of said adjacent legs having a unidirectional conductor means for permitting current to flow in one direction with respect to said input terminal and the second of said adjacent legs having a unidirectional conductor means for permitting current to flow in the other direction with respect to said input terminal; the juncture of said first legs of said sides defining a first output terminal, and the juncture of said second legs of said sides defining a second output terminal; and iv. switch means for maintaining said regulated voltage power source connected in a signalled bucking relationship with said wheel motors regardless of the direction of travel of said vehicle; said switch means comprising a first group of switches responsively connected with said fifth means for serially connecting a first output terminal of said bridge means, said wheel motors, said regulated voltage power source, and said current sensitive relay for current flow in one direction through said wheel motors; and a second group of switches responsively connected with said fifth means for serially connecting a second output terminal of said bridge means, said wheel motors, said regulated voltage power source, and said current sensitive relay for current flow in a second direction through said wheel motors.

Claim 9

The control system of claim 4 wherein said regulated voltage power source, said unidirectional conductor, and said current sensitive relay are serially connected with a pair of bucking terminals; and wherein said switch means comprises three pair of contacts, only one contact of each said pair being closed at a time; one pair of said contacts being disposed intermediate and connected with said pair of bucking terminals and one side of said regulated voltage power source; a second pair of said contacts being disposed intermediate and connected with said pair of bucking terminals and the other side of said regulated voltage power source; and the third pair of said contacts connected with one of said bucking terminals and the respective output terminals of said bridge means, one contact of said third pair being connected with one output terminal and the other contact of said third pair being connected with the other output terminal; said other bucking terminal being connected with the sides of said wheel motors opposite to the sides that are connected with respective input terminals of said bridge means.