Combination siphon and positive action pump

Claim 1

A combination vacuum lift pump and siphon for handling liquids, comprising in combination: (a) a pump cylinder having an inlet adjacent its bottom, and an outlet spaced downward from its top, (b) a discharge line connected to said outlet and depending therefrom, (c) a plunger reciprocatable in the cylinder, including a piston movable from a location low in the cylinder to a location above the said outlet, (d) said piston having a check valve operable to be closed when the plunger is lifted to raise the piston, (e) an additional check valve connected with said inlet to restrain movement of liquid out of the cylinder through said inlet, (f) reciprocative movements of said piston in portions of said cylinder below said outlet being operative to vacuum lift liquid into the cylinder through said inlet, and to force said liquid out of said outlet, (g) said piston when raised in the cylinder above said outlet enabling a siphon action to occur whereby gravity flow of liquid through said discharge line will suck liquid into the cylinder through said inlet and past said inlet check valve, (h) said additional check valve comprising an apertured valve plate disposed at the bottom of the cylinder and in the path of liquid flow, (i) a valve membrane adjacent said plate and adapted to close off the apertures therein in response to the tendency for liquid to flow in one direction, (j) said apertured valve plate and said membrane having central openings adapted to be aligned with one another, (k) a securement thimble extending through said aligned openings and retaining the membrane against permanent dislodgement from the apertured valve plate, (l) said thimble having spaced-apart annular shoulder means, one of said shoulder means being engageable with said plate and the other of said shoulder means being engageable with the membrane to enable the latter to occupy a position completely spaced from the plate under the action of liquid flowing into the inlet, (m) the distance between said shoulder means being substantially in excess of the combined thicknesses of the plate and membrane in order to permit the latter to occupy said spaced position with respect to said plate, so as to present minimal impedement to the flow of liquid through said apertures when the membrane is spaced from the plate, (n) said thimble being loosely carried by both the apertured valve plate and the membrane, so as not to interfere with movement of the latter away from the apertures under the action of liquid flowing therethrough.