Abstract: A hydraulically activated diaphragm pump. A pressure source is coupled to a pump diaphragm during a pump discharge stroke. During this discharge stroke, an air activated return assist cylinder is vented to atmosphere. On the return stroke the pump housing above the diaphragm is vented and the air cylinder activated. A single 4-way solenoid actuated valve controlled by an adjustable timer accomplishes this cylic pumping action. The timer is adjustable to set the number of pump cycles per minute and also adjusts the discharge stroke period of each cycle. A pressure regulator adjusts the pressure of air routed through the solenoid actuated valve to provide relatively high pressure air to the diaphragm on the discharge and low pressure air to the air cylinder on the return stroke.

Abstract: A diaphragm pump with mechanical return stroke assist. The pump includes a flexible diaphragm within a pump housing which is driven by a pressurized fluid during a power stroke and returned to an initial position during a return stroke. The mechanical assist includes a spring and metal rod attached to the diaphragm. During the power stroke the spring stretches and stores potential energy that is released as the tensioned spring and tension rod pull the diaphragm back to an initial position during the return stroke.