摘要 |
A flow control valve for controlling the flow of heat-exchange medium in a circuit of a heat-exchanger is actuated into its open position by air at subatmospheric pressure derived from the intake manifold of an internal combustion engine of a motor vehicle the climate in the interior of which is to be controlled. An auxiliary mechanism is provided which, in the event of malfunction of the pneumatically operated actuator of the flow-through valve, can be manually displaced into an end position in which it holds the valve member in its open position, thus permitting the climate-controlling arrangement to work despite the failure of the pneumatically operated actuator. The auxiliary mechanism includes a bracket-shaped rocker-arm lever tiltably mounted on the housing of the flow-through valve, and a leaf spring which, in each of the end positions of the lever, acts on the latter in such a way as to keep it in its then assumed end position. The valve housing has slots through which an energizing portion of the lever extends to the exterior of the housing of the flow-through valve to be accessible thereat for manual tilting of the lever. |