초록 ▼

A flow indicator for a positive displacement pump is connected to a liquid supply reservoir below the liquid level in the reservoir. The indicator has a first passage through which liquid is supplied from the reservoir to the inlet of the pump. The first passage has an inlet below the liquid level i

A flow indicator for a positive displacement pump is connected to a liquid supply reservoir below the liquid level in the reservoir. The indicator has a first passage through which liquid is supplied from the reservoir to the inlet of the pump. The first passage has an inlet below the liquid level in the reservoir and an outlet coupled to a supply conduit in turn coupled to the pump inlet. A restrictor is positioned in the first passage adjacent the inlet to partially restrict fluid flow through the passage. A secondary passage is coupled in fluid communication with the first passage downstream from the restrictor. A transparent tube is coupled to the secondary passage and extends upwardly alongside the reservoir to a location above the liquid level in the reservoir. A float is slidably positioned in the transparent tube. When the pump is not operating or is functioning on a return stroke, as opposed to a suction stroke, the liquid level in the tube seeks the same as the liquid level in the reservoir, thereby positioning the float adjacent the liquid level in the reservoir. When the pump draws liquid from the reservoir through the flow indicator, the restrictor is sized so that only a portion of the liquid is drawn from the reservoir, while the remaining liquid is drawn through the secondary passage from the transparent tube. As liquid is drawn from the reservoir and the transparent tube, the liquid level in the tube lowers, causing the float to visibly drop within the tube. The restrictor is sized so that during the return stroke of the pump liquid flows from the reservoir into the transparent tube, returning the liquid level in the tube and thus the float to the same level as the reservoir liquid level.

대표청구항 ▼

In a fluid supply system including a source of liquid to be pumped and a positive displacement liquid pump, an improved flow indicator for a positive displacement pump comprising: first means defining a first passage, said first passage having an inlet and an outlet, said inlet being adapted for cou

In a fluid supply system including a source of liquid to be pumped and a positive displacement liquid pump, an improved flow indicator for a positive displacement pump comprising: first means defining a first passage, said first passage having an inlet and an outlet, said inlet being adapted for coupling to said source of liquid to be pumped, said outlet being adapted for connection to the inlet of said positive displacement liquid pump, second means defining a second passage having an inlet and an outlet, said second means being at least partially transparent, said outlet being open to the atmosphere at a position above the surface of said source of liquid, said inlet being in fluid communication with said first passage at a location between the inlet and outlet of said first passage, restriction means in said first passage for partially restricting flow through said first passage, said restriction means being located between the inlet to said first passage and the location at which said second passage is in fluid communication with said first passage, and float means movably positioned in said second passage for movement along said passage in reaction to a variation in fluid level in said second passage.