AN IMPROVED STEAM TRAP
Year: 1871

page_text: LETTERS PATENT to William Robinson, of Guide Bridge, in the
County of Lancaster, for the Invention of "AN IMPROVED STEAM
TRAP."
Scaled the 20th June 1871, and dated the 31st January 1871.
PROVISIONAL SPECIFICATION left by the said William Robinson at
the Office of the Commissioners of Patents, with his Petition, on
the 31st January 1871.
I, WILLIAM ROBINSON, of Guide Bridge, in the County of Lancaster,
do hereby declare the nature of the said Invention for "AN IMPROVED
STEAM TRAP," to be as follows:-
This Invention relates to an improved arrangement of apparatus
called a "steam trap" designed for the purpose of allowing of the
escape of air and condensed water from steam pipes, steam chests,
drying cylinders, and so forth, and at the same time to prevent the
escape of the steam.
At the lower end of the escape pipe a is fixed a hollow conical
plug b in a horizontal position, and on this plug is fitted a socket or

page_text: faucet c capable of turning thereon, and from this socket lead two
pipes d and e, one on each side of the plug. The latter has two ways
or openings, and the faucet with its inlet and outlet pipes oscillates
thereon (like the beam of a pair of scales) and thus acts as a two-way
cock. To the end of the inlet pipe d, which is turned slightly down-
wards, is connected a hollow ball, and from the bottom of the latter a
communicating pipe i, i, leads into the outlet pipe e on the other side
of the plug. The outlet pipe e, the end of which is also bent downwards,
is provided with a balance weight having a tendency to raise the
ball. In the first position of the apparatus, as shown in dotted lines
at Fig. 1, when the steam is admitted into the pipes the air therein
contained first escapes by the opening f and pipe e. The water of
condensation follows and falls through the opening g into the ball h,
and as soon as the steam follows it forces the water out of the ball h
along the communicating pipe i and through the outlet e, and the
ball becoming lighter the counterbalance weight raises it and almost
entirely shuts off the escape of the steam. As the water of condensation
accumulates from time to time it passes through the very narrow
opening left at g into the ball h, and as that gets heavier in conse-
quence it oscillates slightly and allows the pressure of steam to force
the water out, and so on continually.
By causing the ball to float in a cistern or vessel of water as shown
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robinson in the Great Seal Patent Office
on the 31st July 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBINSON, of Guide Bridge, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of January, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robinson, Her special licence
that I, the said William Robinson, my executors, administrators, and
assigns, or such others as I, the said William Robinson, my executors,

page_text: administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
STEAM TRAP," upon the condition (amongst others) that I, the said
William Robinson, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Robinson, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention relates to an improved arrangement of apparatus,
called a steam trap, designed for the purpose of allowing of the escape
of air and condensed water from steam pipes, steam chests, drying
cylinders, and so forth, and at the same time to prevent the escape of the
steam; and this Invention consists, in the use and application to the
purpose of a three-way cock, the hollow plug of which is fixed in a
horizontal position, by preference inside a casing containing water, and
is connected to the steam pipe or other vessel, at or near its lowest
point. Two passages are formed through the plug of the cock corre-
sponding with passages formed through the tail ends of the body of such
cock, one of which tails is extended upwards and forms the escape for
the air from the steam pipe and the other or lower tail is connected to a
hollow float which forms the medium of escape for the condensed water
as herein-after described.
In order that my Invention may be more readily understood and
explained in detail, I have hereunto annexed a Drawing, made upon
a scale of about half size, similar letters of reference being marked upon
all the Figures alike.
Fig. 1 is a side sectional view; Fig. 2, an end sectional view;
and Fig. 3, a plan of a steam trap constructed according to this
Invention.

page_text: A represents a metallic cistern or box which may be open to the
atmosphere at the top, or may be closed with a loose cover B, as seen
in Figs. 1 and 2. This cistern or box contains water up to the level of
the overflow pipe C which is arranged to carry off any surplus water
as it escapes from the steam pipe. Inside this cistern and above the
level of the water is fixed in a horizontal position a hollow tapered
plug D (scen in section, in Figs. 1 and 2) the back extremity of which
plug marked E passes through one side of the cistern and is there con-
nected to the steam pipe or other vessel from which it is desired to with-
draw the air and condensed water. Upon this plug (which forms part of a
three-way cock) the body F of the cock is mounted, and branching from
such body are two tail pipes G and H) the extremity or nose of the
upper one (marked G) being bent downwards and forming the escape
for the air and the lower tail (marked H being connected by a pipe I
to a hollow metallic float J which has a vent pipe K (seen in Fig. 1)
loosely screwed into it at the top, as illustrated, and extending down
inside such float to near the bottom where a small hole or aperture a
is formed to allow of the escape of the water which would otherwise
gather below the bottom of such vent pipe. Two passages are formed
through the hollow plug D, the upper one (marked L) corresponding
with a passage leading into the tail pipe G, and the lower one
(marked M) corresponding with a passage leading through the tail
pipe H into the pipe I, and from thence into the inside of the float J.
The method of fixing this steam trap is as follows:-The hollow plug D
is connected by its screwed tail E to the steam pipe or other vessel
from which it is required to withdraw the air and condensed water, the
cistern A being now filled with water and the vent pipe K being un-
screwed and removed the float J should then be filled with water, this
done the vent pipe K may be replaced in the float, being screwed loosely
into its original position, as it does not require to be air-tight. The
float J will then sink in the cistern A to the position indicated by
dotted lines in Fig. 1 and thus open the passages in the three-way cock
to the widest extent, the steam trap is now ready for action, and the
steam being turned on, any air lodging in the steam pipe or other
vessel to which the trap may be connected will first find its way into
the hollow plug D from whence it will escape through the passage L and
the tail pipe G, the water will next find its way into the hollow plug D,
and flow away through both passages L and M until the arrival of the

page_text: steam, which will force all the water out of the float J through the vent
pipe K causing such float to become buoyant, when it will consequently
rise in the cistern and float on the water as illustrated, thereby com-
pletely closing the passage L and leaving the passage M just sufficiently
open to allow the condensed water to trickle down into the float until
it has accumulated therein in sufficient quantity, when the float will
again sink and open a wider passage for the admission of steam which
will force the condensed water out of the float through the vent pipe K
and then rise again to float on the top of the water as before.
Instead of having the float J in a cistern containing water the tail
pipe G may be extended and have a weight affixed at its extremity to
counterbalance the float, and thus the cistern and water may be dispensed
with.
Having thus particularly described and ascertained the nature of my
Invention, together with the best methods with which I am acquainted
for carrying the same into practical effect, I wish it to be understood
that I do not confine myself to the precise details, relative proportions,
shapes, or dimensions of the various parts of my apparatus illustrated on
the accompanying Drawing, as the same may be considerably varied
without departing from the Invention, but what I claim is the use and
application of a three-way cock in conjunction with a hollow float when
arranged and working substantially as and for the purpose herein-before
described and illustrated on the accompanying Drawing.
In witness whereof, I, the said William Robinson, have hereunto
set my hand and affixed my seal, this Twentieth day of July,
in the year of our Lord One thousand eight hundred and
seventy-onc.