Improvements in Automatic Relief Valves.
Year: 1896

page_text: Date of Application, 12th Aug., 1896-Accepted, 14th Nov., 1896
COMPLETE SPECIFICATION.
Improvements in Automatic Relief Valves.
I, FRANK HENNE BÖHLE of Erie Avenue, South Chicago, Cook County,
Illinois, U.S.A., Manufacturer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of my invention is to provide a valve which shall be operated to open,
for the purpose of relief, by back pressure, particularly that from a vacuum or
condensing engine, or by any light back pressure.
Referring to the accompanying drawing:-
Fig. 1 shews my improved valve device by a view in sectional elevation, and
Fig. 2 is a diagrammatic view shewing my improved valve in position in the
exhaust pipe of an engine connected with a condenser.
A is the shell or valve chamber having an inlet c and an outlet c¹ and cast with a
seat A¹ near one end, preferably of the spider form shewn, whereby the seating
points for the valve B are about the edge portion of the spider and upon its centre
or hub portion r. The valve B is a disc valve having the seating portions p, p,
each provided with suitable packing, and at which it fits accurately upon the seat A¹
with an air tight or practically air tight junction. The valve B carries at its outer
side a tube o through which and, loosely through the centre of the disc valve passes
a stem n which is screwed or otherwise rigidly fastened at its inner end to the
hub r.
A light spring m surrounds the stem and is confined thereon between the
valve and a head in the tube fastened on the outer end of the stem.
The tube with its confined spring affords a dash pot C for a purpose hereinafter
described.
From one side of the tube o extends a lug k from which the tube is connected by
a crank arm i at an elongated opening therein with a shaft h journalled in the
shell beyond which it projects and carries at its projecting end a lever h' on which
may be adjustably supported a weight y.
To render the internal parts of the device accessible without disconnecting it
from its operative position the shell A should be opened at one side and have the
opening covered by a removable plate f.
To use my improved valve device for relieving back pressure from the exhaust
of an engine to a condenser it is coupled into an exhaust D' behind the connection
therewith through a pipe e of an engine indicated at D, and which exhaust pipe
opens to the atmosphere as through the roof of a building, and at the discharge end
of the exhaust pipe is a condenser indicated at E.
In case of any such impairment of the condenser as causes it to fail in exhausting
from the engine the consequent back pressure produced by the exhaust in the
pipe D' against the valve B removes the latter from its seat and permits the
exhaust to escape by way of the outlet g', thereby preventing any damage to
the machinery. In moving away from its seat the valve carries the tube o with it
and compresses the spring m against the head about which the air in the tube
compressed therein, to afford a cushion by the opening of the valve, may escape.
The air cushion or dash pot thus renders the action of the valve practically
noiseless.
The moment that the back pressure ceases and when there is no back pressure
against the valve B it is closed by the spring m, but when it is desired as it
sometimes is, to maintain a light back pressure in the exhaust pipe, the weight g

page_text: may be adjusted on the lever h to normally maintain the valve slightly off its
seat and thus leave the valve device open for the partial escape of the back
pressure.
My improved valve device may be made so extremely sensitive as to open with
the slightest, even the fraction of an ounce, of back pressure and it may be adjusted
and operated equally well in any position.
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 :-
1. A back pressure valve comprising in combination, a chamber provided with an
inlet and an outlet and containing a valve seat, a valve in the chamber, a dash pot
containing a light spring compressed against the valve, and normally holding it
against its seat, a shaft journalled in the shell and connected with the dash pot, and
a lever on the shaft carrying an adjustable weight, substantially as described and
shewn.
2. A back pressure valve comprising in combination, a chamber A provided with
an inlet and an outlet and containing a spider shaped valve seat A', a disc valve B
having packed seating portions p and p¹ formed to bear against said seat about its
margin and at its central portion, and carrying a cylinder o, a rod n fastened to
said seat to extend through the valve into said cylinder and provided at its outer
end with a head t, and a spring m confined in the cylinder about the rod between
the valve and said head, substantially as described and shewn.
Dated this 12th day of August 1896.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C., Agent for the Applicant.