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US 4,285,465 AGranted
Thermostatic devices
AssigneeWalker Crosweller & Company Limited
InventorRoyston J. North
Life of this patent
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AssigneeWalker Crosweller & Company Limited
InventorRoyston J. North
Estimating the term…
A thermoscopic unit such as for use in a thermostat of a fluid mixing valve comprising a hollow body in which a cylindrical convoluted bellows unit is located and sealed to the body to define an expansion chamber in which a thermally responsive material, such as wax, is contained. Temperature changes resulting in a change of volume of the material in the expansion chamber apply an external pressure to change the axial length of the bellows unit, and this may be operably connected to an actuator for a valve assembly. Preferably, there is a reservoir of the material constituted by a tubular coil encircling the hollow body, or a hollow cone extending therefrom. Such reservoir is filled with the material and is in communication with the expansion chamber and provides additional heat transfer surfaces to give fast response to temperature changes.
A thermostatic device for an ablutionary water mixing appliance, said device comprising a housing, valve means axially movable within said housing for controlling the proportions of fluids to be mixed, a thermoscopic device mounted in said housing so that mixed fluid flows over the external surfaces of said thermoscopic unit, an actuator operable connected to said thermoscopic unit for controlling movement of said valve means, said thermoscopic unit comprising a bellows unit mounted within a hollow body located in said housing, an expansion chamber defined between said bellows unit and said hollow body and containing thermally responsive material, the thermally responsive material comprising a wax based material selected for the temperature range of use and having a liquid phase at the higher temperatures of said range, said actuator being movable by responsive movement of the thermoscopic unit on change of temperature of the mixed fluid.
A thermoscopic unit for an ablutionary water mixing appliance, said unit comprising a hollow body housing, a bellows unit, said bellows unit comprising a convoluted hollow cylindrical member closed at one end and the opposed end being in sealing engagement with said hollow body, an expansion chamber defined between said housing and said bellows unit, a tubular coil encircling said hollow body in spaced relationship thereto and having one end in communication with said expansion chamber and the other end sealed, thermally responsive material contained in said expansion chamber and said coil and confined therein by said sealing engagement of said bellows unit to said hollow body, said thermally responsive material comprising a wax based material selected for the temperature range of use and having a liquid phase at the higher temperatures of said range.
Dependencies are inferred from the claim text.