Zone control valve assembly

Claim 2

A control valve assembly comprising a valve body having an inlet and an outlet port, a passage communicating between said inlet and outlet ports, valve means mounted in said valve body for controlling fluid flow through said passage, stem means for positioning said valve means relative to said passage, temperature responsive means, output means operated by said tEmperature responsive means, said output means operatively engaging said stem means to open and close fluid flow through said passage, means responsive to the detachment of said output means for causing said valve means to prevent flow from said passage from reaching said stem means, wherein said temperature responsive means comprises a heat motor, and a driven member responsive to movement of said heat motor, and means preventing movement of said driven member at lower than a predetermined amount of force generated by said motor, said preventing means operative when said predetermined force is generated by said motor to assist said motor in moving said driven member.

Claim 3

An assembly as claimed in claim 1, wherein said driven member comprises a pivotal armed member, and said preventing means comprises a torsion spring.

Claim 4

An assembly as claimed in claim 2, wherein there is means holding said torsion spring against unwinding at lower than said predetermined force.

Claim 5

A fluid control valve comprising: support structure, a valve body having an inlet, an outlet and a port communicating between said inlet and said outlet, a stem member mounted for axial movement within said body, said stem member having a valve disc mounted thereon for axial movement therewith to open and close said port, a motion transmitting member coupled to said stem member to axially move said stem member, a motor mounted on said support structure and having an element extensible therefrom on operation of the motor, said extensible element being operably adjacent said motion transmitting member to impart a moving force to the motion transmitting member responsive to extension of said element thereby to move said valve disc relative to said port, an electric switch having a plurality of contacts and a switch operating member for opening and closing said contacts in response to movement of said motion transmitting member, and bias means mounted to oppose movement of said motion transmitting member, said bias means configured to lessen its opposing movement force against said motion transmitting member when more than a predetermined force is applied by said motor extensible element to said motion transmitting member.

Claim 6

A fluid control valve comprising: support structure, a valve body having an inlet, an outlet and a port communicating between said inlet and said outlet, a stem member mounted for axial movement within said body, said stem member having a valve disc mounted thereon for axial movement therewith to open and close said port, a motion transmitting member coupled to said stem member to axially move said stem member, a motor mounted on said support structure and having an element extensible therefrom on operation of the motor, said extensible element being operably adjacent said motion transmitting member to impart a moving force to the motion transmitting member responsive to extension of said element thereby to move said valve disc relative to said port, an electric switch having a plurality of contacts and a switch operating member for opening and closing said contacts in response to movement of said motion transmitting member, and bias means mounted to oppose movement of said motion transmitting member, said bias means configured to lessen its opposing movement force against said motion transmitting member when more than a predetermined force is applied by said motor extensible element to said motion transmitting member.

Claim 7

A valve as claimed in claim 4, wherein said motion transmitting member comprises a bell crank mounted pivotally with a first arm positioned adjacent the said element for response to the extension thereof, and a second arm, with said second arm being coupled to said stem member.

Claim 8

A valve as claimed in claim 5, wherein said bias means comprises a torsion spring, said spring engaging the second arm of said bell crank and said spring configured to wind responsive to extension of said element whereby to lessen the spring force opposing movement of said bell crank.