Wheel slip protection device

Claim 2

Wheel slip protection device comprising, in combination, acceleration-responsive means connected to a wheel of an electric motor-driven vehicle and deriving an acceleration signal corresponding to positive and negative accelerations of the wheel; and slip control means connected to the output of said acceleration-responsive means, and including first means operable, responsive to said acceleration signal attaining a predetermined magnitude, to derive a first tractive force reduction signal component which is largely variable during wheel slippage, second means operable, responsive to said acceleration signal attaining said predetermined magnitude, to derive a second tractive force reduction signal component which is substantially constant during wheel slippage, and third means connected to said first and second means and, responsive to said first and second signal components, modulating the motor current, in accordance with the prevailing adhesive force between said wheel and its support surface, to reduce said accelerations to substantially zero.

Claim 3

Wheel slip protection device comprising, in combination, acceleration-responsive means connected to a wheel of a vehicle and deriving an acceleration signal corresponding to positive and negative accelerations of the wheel; and slip control means connected to the output of said acceleration-responsive means, and including first means operable, responsive to said acceleration signal attaining a predetermined magnitude, to derive a first tractive force reduction signal component which is largely variable during wheel slippage, and second means operable, responsive to said acceleration signal attaining said predetermined magnitude, to derive a second tractive force reduction signal component which is substantially constant during wheel slippage; said acceleration-responsive means comprising tachogenerator means and differentiation means connected to the output of said tachogenerator means and to the input of said slip control means; said slip control means including two limit value indicators each having an output connected to an input of an OR gate; said first means including circuit arrangement means connected to the output of said differentiation means, to another output of one of said limit value indicators and to an output of said OR gate; said second means comprising a first circuit arrangement connected to another output of said OR gate.

Claim 4

Wheel slip protection device comprising, in combination, acceleration-responsive means connected to a wheel of a vehicle and deriving an acceleration signal corresponding to positive and negative accelerations of the wheel; and slip control means connected to the output of said acceleration-responsive means, and including first means operable, responsive to said acceleration signal attaining a predetermined magnitude, to derive a first tractive force reduction signal component which is largely variable during wheel slippage, and second means operable, responsive to said acceleration signal attaining said predetermined magnitude, to derive a second tractive force reduction signal component which is substantially constant during wheel slippage; said acceleration-responsive means comprising tachogenerator means and differentiation means connected to the output of said tachogenerator means and to the input of said slip control means; said slip control means including two limit value indicators each having an output connected to an input of an OR gate; said first means including circuit arrangement means connected to the output of said differentiation means, to another output of one of said limit value indicators and to an output of said OR gate; said second means comprising a first circuit arrangement connected to another output of said OR gate.

Claim 5

Wheel slip protection device, as claimed in claim 2, in which said first circuit arrangement is connected to the forward output of said OR gate and includes resistors, diodes and a capacitor deriving said second tractive force reduction signal component; said circuit arrangement means including a second circuit arrangement connected to the reverse output of said OR gate and including resistors and a diode, a third circuit arrangement connected to the reverse output of said first limit value indicator and comprising resistors, a diode and a Zener diode, and a fourth circuit arrangement connected to the output of said differentiation means and including resistors, a diode and an amplifier; said first means further including an amplifier connected to the outputs of said second, third and fourth circuit arrangements, and a feedback capacitor connected across said last-named amplifier.

Claim 6

Wheel slip protection device, as claimed in claim 2, in which said tachogenerator is a medium frequency generator, said tachogenerator means further including a rectifier bridge connected to the output of said tachogenerator, a choke having one end connected to the output of said rectifier bridge, and a first capacitor connected to the other end of said choke; said differentiation means comprising a first amplifier and a second capacitor connected between the input of said first amplifier and the other terminal of said choke.

Claim 7

Wheel slip protection device, as claimed in claim 4, in which said differentiation means further includes a feedback resistor bridging said first amplifier.

Claim 8

Wheel slip protection device, as claimed in claim 2, in which said first circuit arrangement comprises a resistor having a first end connected to a sourCe of positive potential; a diode having its cathode connected to the second end of said resistor; a capacitor connected between said second end of said resistor and ground; a second resistor connected to said second end of said first-mentioned resistor; a second diode bridging said second resistor and having its anode connected to said second end of said first-mentioned resistor; and means connecting the cathode of said diode to the forward output of said OR gate.

Claim 9

Wheel slip protection device, as claimed in claim 2, in which said circuit arrangement means includes a second circuit arrangement; said second circuit arrangement including a resistor having its first end connected to a source of positive potential; a diode having its cathode connected to the second end of said resistor; a second resistor connected to the anode of said diode; and a third resistor connected between the cathode of said diode and the reverse output terminal of said OR gate.

Claim 10

Wheel slip protection device, as claimed in claim 2, in which said circuit arrangement means includes a third circuit arrangement; said third circuit arrangement including a first resistor having a first end connected to a source of positive potential; a first diode having its anode connected to the second end of said first resistor; a second resistor connected to the cathode of said first diode; and a Zener diode connected between said second end of said first resistor and the reverse output of said first limit value indicator.

Claim 11

Wheel slip protection device, as claimed in claim 2, in which said circuit arrangement means includes a fourth circuit arrangement; said fourth circuit arrangement including a first resistor having a first end connected to the output of said differentiation means; an amplifier having its input connected to the second end of said first resistor; a second resistor having its first end connected to a source of negative potential and its second end connected to the input of said amplifier; a diode having its cathode connected to the output of said amplifier; and a third resistor connected in series with the anode of said diode.

Claim 12

Wheel slip protection device, as claimed in claim 2, including a controlled rectifier bridge having a control signal input connected to the output of said slip control means; a source of AC potential connected to the input of said controlled rectifier bridge; and a unidirectional undulating current, series wound commutator motor connected to the output of said controlled rectifier bridge and providing said tractive force to said wheel.