An Improved Air-chamber for Pumps and the like.
Year: 1897

page_text: Date of Application, 12th May, 1897-Accepted, 12th June, 1897
COMPLETE SPECIFICATION.
An Improved Air-chamber for Pumps and the like.
I, GEORGE HUGHES, Patent Agent of 23, Coleman Street, London, E.C., do
hereby declare the nature of this invention, (a communication to me from abroad by
Carl Steier, Locksmith, and Johann Koller, Sculptor, Painter and Gilder, both of
Neumarkt, Germany), and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention relates to an improved air-chamber for pumps and the like, which
performs the dual office of air-chainber and "back stroke" valve.
The accompanying drawing shews a vertical section. a is a cylinder or chamber
having the inlet opening b, and an outlet opening c, and also a cover d tightly bolted
over a. Within the cylinder a is the piston e which is made thoroughly air-tight by
the packing and rings g firmly screwed thereto. A spindle h runs from the bottom
of the piston e and through the stuffing box i provided in cover d of cylinder a.
spindle carries at its lower end a flange k against which presses one end of a spiral
spring, surrounding the spindle h, the other end of the spring pressing against
the end of the stuffing box i, thus keeping e pressed against the bottom of the
cylinder a.
The
Compared with hitherto known air-chambers, in which only the elasticity of the
cushion of air therein is available, the new apparatus secures an easy working of the
pump and absence from shock. On one hand the liquid entering by b opens the out-
let e gradually and without shock by raising the piston e, and on the other hand the
piston e is forced back by the spring thereby closing the outlet c, and thus acting as
a back stroke or return valve.
One of the advantages of the present construction, is the arrangement of the spring
which can be removed or exchanged without interference with the working. Another
advantage is, that when the liquid enters the air-chamber in the first instance, the
piston acted on by the spring tends to force the fluid out at c, whereas in air-chambers
as at present made, the chamber must be filled with liquid before this takes place.
Further, the piston e acting also as a back stroke or return valve, prevents the entrance
of "false" air, by which I mean air absorbed by the water before being pumped, and
which during pumping is set free and escapes between the piston and the pump
cylinder.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
An air-chamber for pumps and the like, the essential features of the said air-chamber
being a piston free to move therein by pressure from the inflowing liquid, the said
piston being pressed towards one end of the chamber so as normally to close the
inlet, and outlet, by a spiral spring encircling the spindle of the said piston, the
whole substantially as described in the above specification and exemplified in the
accompanying drawing.
Dated this 10th day of May 1807
HUGHES & YOUNG,
28, Coleman Street, London, E.C., Agents for Applicant.