US 187719

Patent Overview — US187719A

Title: "Improvement in pumps for town and city supply"
Inventor: William H. Lang, of Vergennes, Vermont
Patent number: US187719A
Publication/grant date: February 27, 1877
Application filed: January 18, 1877
Classification: F04B1/02 — multi-cylinder pumps having two cylinders
Assignee: None identified in the supplied text

Purpose. The invention addresses pumps "adapted and intended for the supply of cities and towns, and especially for pumping into the mains direct." The specification states the duty required of such pumps "is very heavy," and that water ram — the reaction when forward flow through a valve momentarily stops — causes "rapid pounding out and destruction of the valve and seat, and the final disabling of the pump."

Plain-language scope. Based only on the supplied text, the disclosure describes:

• Lower check-valves (K) arranged relative to each other and to an air-chamber (I) opening downward into the suction-pipe, so all lower valves are "equally relieved" of water ram; a four-valve trunk placed equidistant from that chamber's center.
• A hollow axial sleeve (L) depending from the upper valve-seat that guides both the lower spindle of the upper valve (J) and the upper spindle of the lower valve (K), keeping the valves in line and reducing unequal wear.
• A small return waterway past the upper valve-seat with a valve to open or close it, for priming and pumping from the upper receiver or main.
• Stationary elastic packing-rings (N), split on one side, positively adjustable from outside the cylinder via a right-and-left adjusting screw (O) while the machine runs.
• A buoyant, sealed hollow plunger (R) to relieve bottom wear, with an air-chamber inside it or a body of specific gravity less than water.
• Two double-acting cylinders coupled to the same suction-pipe and receiver, with cranks set at right angles; chest (B) and receiver (D) are "similar" and cast from the same patterns.

The text presents several claims, including the split packing-ring with external adjustment, and the horizontal cylinder with buoyant piston.

Not established by the excerpt. The supplied text provides no assignee or ownership information, no litigation or validity data, no prior-art comparison beyond the general statement that the general features "are similar to other plunger-pumps," and no full claim set. The excerpt is partial ("[Excerpt only; consult the source for omitted text.]"), so details of the omitted passages — including complete claims and figures — cannot be stated here.

Source: https://patents.google.com/patent/[US187719](/patent/US187719)/en