Road vehicle power assisted steering system
First Claim
1. A vehicle power steering system comprising:
- a steering gear having a steering output member displaceable to effect steering of steerable wheels in response to rotation of a steering wheel of the vehicle;
an electric motor for providing power assistance to displacement of said steering output member in response to electric current applied to said electric motor;
a source of electrical current;
control means for providing a control signal having a value responsive to applied steering torque and vehicle speed; and
logic control means for connecting a load having a fixed resistive value across said electric motor when said control signal falls below a predetermined value to dissipate electrical energy and thereby brake the electric motor.
1 Assignment
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Accused Products
Abstract
A road vehicle power assisted steering system comprises a power assisted steering gear assembly (1) in which power assistance to the displacement of an output member of the steering gear (1) is provided by an electric motor in response to a steering gear torque applied to the input member (2). Motorcon also of the electric motor are capable of being switched from a power supply (10), to a resistive load and are controlled by control means (11) in response to the steering torque so that any kinetic energy of the displaceable components of the steering gear (1) may be dissipated by the resistive load to which the coils are switched by the control means when the steering torque falls below a predetermined value.
19 Citations
8 Claims
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1. A vehicle power steering system comprising:
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a steering gear having a steering output member displaceable to effect steering of steerable wheels in response to rotation of a steering wheel of the vehicle; an electric motor for providing power assistance to displacement of said steering output member in response to electric current applied to said electric motor; a source of electrical current; control means for providing a control signal having a value responsive to applied steering torque and vehicle speed; and logic control means for connecting a load having a fixed resistive value across said electric motor when said control signal falls below a predetermined value to dissipate electrical energy and thereby brake the electric motor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification