Power steering device

Claim 2

A steering device for a motor vehicle steering system comprising a rack and pinion steering gear, a steering gear actuator and a power steering valve; said steering gear actuator having an input sprocket constructed to be connected to a vehicle steering wheel; said actuator having an output sprocket connected to the pinion of said rack and pinion steering gear; a drive chain drivingly interconnecting said input and output sprockets; a chain tensioner having a parallelogram linkage system; element; said pair of L-shape members having inwardly directed overlapping arms; spring means coupled to said members and urging each of said members into engagement with said chain at a pair of spaced locations; said spring means engaging said overlapping arms and urging one of said members in a counterclockwise direction and the other of said members in a clockwise direction; said spring urged members biasing portions of said chain into generally ogee configurations; said members and said linkage system being displaceable when one of said chain portions is under a tensile load; a power steering valve having a laterally displaceable valve elemtn; said power steering valve being constructed to provide communication between a fluid pressure source and a power steering booster cylinder in accordance with the position of said displaceable valve element; means coupling said valve element with said chain tensioner; said coupling means being constructed to displace said valve element in response to displacement of said chain tensioner when said one portion of said chain is under a tensile load.

Claim 3

A steering device for a motor vehicle steering system comprising a rack and pinion steering gear, a steering gear actuator and a power steering valve; said steering gear actuator having an input sprocket constructed to be connected to a vehicle steering wheel; said actuator having an output sprocket connected to the pinion of said rack and pinion steering gear; a drive chain drivingly interconnecting said input and output sprockets; a chain tensioner having a parallelogram linkage system; element; said pair of L-shape members having inwardly directed overlapping arms; spring means coupled to said members and urging each of said members into engagement with said chain at a pair of spaced locations; said spring means engaging said overlapping arms and urging one of said members in a counterclockwise direction and the other of said members in a clockwise direction; said spring urged members biasing portions of said chain into generally ogee configurations; said members and said linkage system being displaceable when one of said chain portions is under a tensile load; a power steering valve having a laterally displaceable valve elemtn; said power steering valve being constructed to provide communication between a fluid pressure source and a power steering booster cylinder in accordance with the position of said displaceable valve element; means coupling said valve element with said chain tensioner; said coupling means being constructed to displace said valve element in response to displacement of said chain tensioner when said one portion of said chain is under a tensile load.

Claim 4

A steering device for a motor vehicle steering system comprising a rack and pinion steering gear, a steering gear actuator and a power steering valve; said steering gear actuator having an input sprocket constructed to be connected to a vehicle steering wheel; said actuator having an output sprocket connected to the pinion of said rack and pinion steering gear; a drive chain drivingly interconnecting said input and output sprockets; a chain tensioner having a parallelogram linkage system; element; said pair of L-shape members having inwardly directed overlapping arms; spring means coupled to said members and urging each of said members into engagement with said chain at a pair of spaced locations; said spring means engaging said overlapping arms and urging one of said members in a counterclockwise direction and the other of said members in a clockwise direction; said spring urged members biasing portions of said chain into generally ogee configurations; said members and said linkage system being displaceable when one of said chain portions is under a tensile load; a power steering valve having a laterally displaceable valve elemtn; said power steering valve being constructed to provide communication between a fluid pressure source and a power steering booster cylinder in accordance with the position of said displaceable valve element; means coupling said valve element with said chain tensioner; said coupling means being constructed to displace said valve element in response to displacement of said chain tensioner when said one portion of said chain is under a tensile load.

Claim 5

A power steering unit for a motor vehicle steering system comprising a housing and an input sprocket rotatably supported in said housing; said input sprocket being constructed to be connected to a vehicle steering wheel; an output sprocket rotatably supported in said housing; a pinion rigidly secured to said output sprocket; a rack slidably supported in said housing and in mesh engagement with said pinion; said rack being constructed to be connected to a steering linkage mechanism; a drive chain drivably interconnecting said input and output sprockets and having laterally spaced apart first and second spans extending between said sprockets; a combination chain tensioner and load sensing means comprising a linkage system supported on said housing and having a laterally displaceable portion; first and second members pivotally supported on said portion of said linkage system and engaging said first and second spans, respectively; each of said members engaging its respective span at two spaced locations; spring means coupled to said first and second members and urging said members into engagement with said first and second spans; each of said spans normally having a generally ogee configuration in response to the spring force exerted by said spring means on said first and second members; said first and second members being laterally displaceable relative to said housing in response to a tensile load in one of said spans that exceeds a tensile load in the other of said spans; a power steering valve having a valve body supported on said housing and a laterally displaceable valve element situated within said body; means coupling said valve element with said first and second members; said coupling means being constructed to displace said valve element in response to displacement of said members when said one span of said chain is placed under a tensile load that exceeds the tensile load in said other span; said power steering valve being constructed to provide communication between a fluid pressure source and a power steering booster cylinder in accordance with the position of said displaceable valve element.

Claim 6

A power steering unit for a motor vehicle steering system comprising a housing and an input sprocket rotatably supported in said housing; said input sprocket being constructed to be connected to a vehicle steering wheel; an output sprocket rotatably supported in said housing; a pinion rigidly secured to said output sprocket; a rack slidably supported in said housing and in mesh engagement with said pinion; said rack being constructed to be connected to a steering linkage mechanism; a drive chain drivably interconnecting said input and output sprockets and having laterally spaced apart first and second spans extending between said sprockets; a combination chain tensioner and load sensing means comprising a linkage system supported on said housing and having a laterally displaceable portion; first and second members pivotally supported on said portion of said linkage system and engaging said first and second spans, respectively; each of said members engaging its respective span at two spaced locations; spring means coupled to said first and second members and urging said members into engagement with said first and second spans; each of said spans normally having a generally ogee configuration in response to the spring force exerted by said spring means on said first and second members; said first and second members being laterally displaceable relative to said housing in response to a tensile load in one of said spans that exceeds a tensile load in the other of said spans; a power steering valve having a valve body supported on said housing and a laterally displaceable valve element situated within said body; means coupling said valve element with said first and second members; said coupling means being constructed to displace said valve element in response to displacement of said members when said one span of said chain is placed under a tensile load that exceeds the tensile load in said other span; said power steering valve being constructed to provide communication between a fluid pressure source and a power steering booster cylinder in accordance with the position of said displaceable valve element.

Claim 7

A power steering unit according to claim 3 and including: said first and second members each having a first leg portion engaging said first and second spans, respectively; said first and second members each having a second leg portion engaging said spring means.

Claim 8

A power steering unit according to claim 4 and including: said first and second members each having a generally L-shape.

Claim 9

A power steering unit according to claim 4 and including: said linkage system being a parallelogram type linkage system.