AN IMPROVED EQUILIBRIUM DISCHARGE OR BLOW-OFF Cock
Year: 1876

page_text: LETTERS PATENT to William Bowker, of the City of Manchester, in the County
of Lancaster, Engineer, for the Invention of "AN IMPROVED EQUILIBRIUM
DISCHARGE OR BLOW-OFF Cock."
PROVISIONAL SPECIFICATION left by the said William Bowker at the Office
of the Commissioners of Patents on the 9th August 1876.
WILLIAM BOWKER, of the City of Manchester, in the County of Lancaster,
Engineer. "AN IMPROVED EQUILIBRIUM DISCHARGE OR BLOW-OFF Cock."
The object of this Invention is to enable steam, gases, water, or compound liquids
to be blown off or discharged from boiler and generators, water mains, pipes,
closets, lavatories, or other vessels or places, with greater speed and efficiency than
has been heretofore accomplished.
The cock consists of a valve box, a valve, a cover, and also a tap for allowing
the interior of the box to open to or be closed from the atmosphere. At the lower
part of the box there is a discharge passage and valve seating, and the area of the
valve at its seating is considerably less than the area of the upper part of the valve
in the box.
The exterior of the upper part or body of the valve is of less diameter than the
interior of the box in which it works, and the area of the annular space is intended
to be larger than the discharge opening in the outer discharge tap.
When there is no blow-off or discharge required the small tap is closed, and the
pressure from the boiler, gas generator, or water supply acting on the larger area of
the upper part of the valve keeps the valve close upon its seating, and no discharge
can take place.
When the steam, gas, or water has to be blown off or discharged the small tap is
opened, and as the area of the small tap is considerably larger than the area of
the annular space the steam, gas, or water passes away quicker than it can be
supplied, and thus the pressure behind the valve is so reduced as to enable the
pressure of the delivery to raise the valve from its seating and open the discharge
passage.
When the discharge has to be shut off the small tap is closed, and as the box is
filled with steam, gas, or water, the pressure acting on the larger area of the valve
forces the smaller area on the valve seating and closes the discharge passage.
1

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Bowker in the Great Seal Patent Office on the 3rd February
1877.
WILLIAM BOWKER, of Manchester, in the County of Lancaster, Engineer.
IMPROVED EQUILIBRIUM DISCHARGE OR BLOW-OFF COCK."
"AN
The object of this Invention is to enable steam, gases, water, or compound liquids
to be blown off or discharged from boilers and generators, water mains, pipes,
closets, lavatories, or other vessels or places, with greater ease, speed, and efficiency
than has heretofore been accomplished.
The cock consists of a valve box, a valve, a cover, and also a small tap or valve
for allowing the interior of the box to be opened to or closed from the atmosphere,
there being at the lower part of the box a valve.seating and discharge passage, and
the area of the valve at its seating is less than the area of the upper part of the
valve in the box.
In one arrangement between the exterior of the upper part or body of the valve
and the interior of the box in which it works there is an annular spaco or passage
forming a communication from the entrance pipe or nozzle of the cock to the upper
part of the valve, and the area of the annular space is intended to be smaller than
the area of the discharge opening of the small tap or valve.
In another arrangement I cause the upper part or body of the valve to be well
fitted to the interior of the box, and make an independent passage of communication
between the supply to the cock and the top of the valve, and when desired, instead
of allowing the small tap or valve to open out direct to the atmosphere I cause it
to communicate with a discharge pipe or reservoir.
These improvements will be clearly understood by referring to the figures and
letters on the accompanying Sheet of Drawings, in which Figs. 1, 2, 3, and 4, are
vertical sections of some of my improved equilibrium discharge or blow-off cocks,
and Figs. 5 and 6 are sectional plans of parts of the same.
In the various Figures a represents the valve box; b, the valve; c, the valvo
seating; d, the cover of the valve box; e, the entrance passage to the valve box;
f, the discharge or blow-off passage or nozzle; and g, the small tap or valve, which
can be opened to or closed from the atmosphere, pipe, or reservoir. Figs. 1 and 2
are sections of brass cocks having screwed covers and screwed discharge passages to
which the discharge pipes are fitted, and in each of these cocks there is an annular
space between the upper part of the valve and the interior of the box, and the
small tap g when opened leads to the atmosphere. In the larger cocks the bulk of
the metal is of cast iron, to which brass valve casings k and seatings c are fitted, and
the covers and discharge pipes are fastened by screws or bolts.
In the cocks represented in Figs. 3, 4, 5, and 6, the outer part of the valve b is
well fitted to the interior of the valve casing k, and the communication between
the entrance of the valve box and the top of the valve is made by passages m, and
in Fig. 3 the tap g opens to the atmosphere, and in Fig. 4 the valve g opens into
a passage n leading to the discharge passage f
In all cases when the steam, gas, or water, has to be blown off or discharged the
small tap or valve g is opened, and as the area of the passage of the small tap or
valve is larger than the area of the annular space l, Figs. 1 and 2, or the passages
m, Figs. 3, 4, and 6; the steam, gas, or water passes away from the valve box
quicker than it can be supplied, and thus the pressure of the steam, gas, or water,
raises the valve b from its seating c and opens the discharge passage f, but when
the discharge has to be shut off the small tap or valve g is closed, and the pressure
of the steam, gas, or water acting on the larger area of the valve b forces the lower
or smaller area tightly on the valve scating and closes the discharge passage.
Having now described the nature and particulars of my said Invention I desire it

page_text: to be understood that I claim, the improved equilibrium discharge or blow-off cocks
as herein herein described and illustrated on the accompanying Sheet of Drawings.
In witness whereof, I, the said William Bowker, have hereunto set my hand
and seal, the Thirteenth day of January, in the year of our Lord One
thousand eight hundred and seventy-seven.
Signed, sealed, and delivered
by the said William Bowker
in the presence of
CHA. W. COLLINS,
Engineer & Patent Agent.
WILLIAM BOWKER. (L.S.)