Solenoid control for a bathtub waste water drain

A drain closure control for a bathtub having a bottom drain and an end wall with interior and exterior sides, and a fluid overflow port in the end above the bottom drain, the control comprising:

• a vertical drain pipe extending downwardly from the overflow port on the interior side of the end wall to a position below the bottom drain,
• a substantially horizontal drain pipe extending from the bottom drain to the vertical drain pipe and being in fluid communication therewith,
• a drop cylinder slidably mounted in the vertical drain pipe adjacent the juncture between the horizontal drain pipe and the vertical drain pipe and being movable between a lower position which closes the horizontal drain pipe, and an upper position which will allow fluid to flow through the horizontal drain pipe and thence downwardly into the vertical drain pipe,
• a single solenoid mounted adjacent the overflow port and having an extensible and retractable plunger for controlling opening and closing of the drain,
• elongated linkage connecting the drop cylinder and the solenoid plunger, whereby movement of the plunger in one direction will raise the drop cylinder to the upper position, and movement of the plunger in the other direction will lower the drop cylinder to the lower position,
• further comprising a solenoid actuator adjacent the overflow port for controlling extension and retraction of the plunger.