Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
122 words
A front and rear wheel steering device for vehicle for variably controlling the steering angle ratio of rear wheels relative to the steering angle of front wheels according to vehicle speed, comprising: a vehicle speed sensor for detecting an actual vehicle speed; storage means for storing a plurality of mathematical functions, including a default mathematical function, representing different steering angle ratio characteristics; manual selection means for selecting one of the mathematical functions of the vehicle speed stored in the storage means; means for achieving a steering angle ratio according to the mathematical function selected on the manual selection means; limiting means which prohibits the manual selection of the mathematical functions other than the default mathematical function according to a predetermined vehicle condition.
Claim 2
Dependent Claim
122 words
A front and rear wheel steering device for vehicle for variably controlling the steering angle ratio of rear wheels relative to the steering angle of front wheels according to vehicle speed, comprising: a vehicle speed sensor for detecting an actual vehicle speed; storage means for storing a plurality of mathematical functions, including a default mathematical function, representing different steering angle ratio characteristics; manual selection means for selecting one of the mathematical functions of the vehicle speed stored in the storage means; means for achieving a steering angle ratio according to the mathematical function selected on the manual selection means; limiting means which prohibits the manual selection of the mathematical functions other than the default mathematical function according to a predetermined vehicle condition.
Claim 3
Dependent Claim
64 words
A front and rear wheel steering device as defined in claim 1, wherein the default mathematical function has negative values in a low speed range and positive values in a high speed range, and the other mathematical functions branch off from the default mathematical function in a low speed range and extend substantially parallel to the default mathematical function in a high speed range.
Claim 4
Dependent Claim
37 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when the actual vehicle speed is greater than a certain value.
Claim 5
Dependent Claim
45 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when the absolute value of the change rate of the actual vehicle speed is greater than a certain value.
Claim 6
Dependent Claim
49 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when the change rate of the actual vehicle speed is greater than a certain positive value or smaller than a certain negative value.
Claim 7
Dependent Claim
39 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when the shift position of the vehicle is in a high speed position.
Claim 8
Dependent Claim
41 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when the actual steering speed of the front wheels is greater than a certain value.
Claim 9
Dependent Claim
45 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when the change rate of the actual steering speed of the front wheels is greater than a certain value.
Claim 10
Dependent Claim
54 words
A front and rear wheel steering device as defined in claim 1 or 2, wherein the limiting means prohibits the manual selection of the mathematical functions when a composite value of the actual steering speed and the change rate of the actual steering speed of the front wheels is greater than a certain value.