Improvements in and relating to Fluid Pressure and Vacuum Gauges.
Year: 1888

page_text: Date of Application, 29th Nov., 1888
Complete Specification Loft, 17th Ang 1889-Accented. 21st Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to Fluid Pressure and Vacuum
Gauges.
I, JOHN BUCHANAN, of 75 Robertson Street, Glasgow, Lanarkshire, Indicator
Maker, do hereby declare the nature of my invention to be as follows:-
This Invention has reference to improvements in and relating to steam or fluid
pressure and vacuum gauges, especially of the Bourdon spring coil and corrugated
or other spring vessel construction, and which improvements will make these gauges
more reliable and less liable to derangement and undue strain.
The nature and novelty of the improvements consist in fitting on the pressure
tube close to the gauge, a two or a three way cock or valve, in place of a single
cock as heretofore, for setting on and off the pressure or vacuum on the gauge quite
over the water inverted siphon or U pressure pipe when that is used. This two or
three way cock or valve is for the purposes in one position of the cock of drawing
itself
gauge
off the water or fluid from the acting hollow tube or vessel of the
through the new side opening or branch, to the atmosphere, while shutting that
leading from the siphon tube, so as to test the gauge and see that the pointer came
back to zero, agreeing to the pressure of the atmosphere, which would be admitted
to the gauge through the draining off orifice, while preventing the displacement of
the water always left in the siphon pipe; and then in the second position of the
handle and cock shutting off the said orifice or branch to the atmosphere, and opening
the pressure water tube to the gauge letting the water act within the gauge to in-
dicate the pressure caused in it by the pressure in the siphon pipe, without allowing
the steam or hot vapour to enter the gauge and heat or strain it, as has been the
case heretofore, when such testing cocks were applied, which drained off the water
or liquid from the siphon and allowed the hot steam or vapour to enter the working
pressure tube of the gauge, which is detrimental to the gauge by straining it under
abnormal heat in addition to the pressure only desired to be indicated. The third
position of the handle, and three way cock, when that is used, would be that of
shutting off the gauge tube from the siphon pressure tube, also from the third or
lateral opening to the atmosphere, when the gauge was not desired to be used.
When desired a stop might be formed on the tap or cock, or both, to prevent
the handle and cock being turned to open the siphon orifice to the atmospheric
orifice, and thus prevent the possibility of the siphon being emptied of the trapping
liquid separating the hot steam or other pressure fluid from entering the acting
gauge or pressure indicating vessel. In some cases an outside drain tube might be
fitted to the lateral orifice leading to the atmosphere to convey the water away and
prevent it from wetting the person or surrounding objects.
T
,
1000
W. R. M. THOMSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Fluid Pressure and Vacuum
Gauges.
I, JOHN BUCHANAN, of 75 Robertson Street, Glasgow, Lanarkshire, Indicator
Maker, 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 in writing, reference being had to the accompanying Sheet of
Drawings, and to the letters and figures marked thereon, that is to say :-
This Invention has reference to improvements in and relating to steam or fluid

page_text: pressure and vacuum gauges, especially of the Bourdon spring coil and corrugated
or other spring vessel construction, and which improvements will make these gauges
more reliable and less subject to derangement and undue strain than heretofore."
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended an explanatory Sheet of Drawings, in which the same reference letters are
used to indicate corresponding parts in all the figures where shown. Figure 1 is a
front elevation showing a steam or fluid pressure gauge G of the Bourdon coil
spring tube construction, and connecting water inverted siphon or U-pressure
pipe A', as fitted with my new or improved arrangement or combination of a two or
a three way cock or valve and key A a for the purposes hereinafter described.
Figure 2 is a sectional elevation of this valve A a corresponding to Figure 1, and
Figure a plan of the same corresponding to Figure 2. While Figure 4 is a
sectional elevation of the valve A a corresponding to Figure 2, but fitted with a
downwardly curved atmospheric discharge nozzle or spout All instead of the coupling
branch A2 and tube A³, shown in Figures 1 to 3, and with the key a and its
handle a", turned at right angles to the position shown in Figure 2, and as dotted
in in Figure 1.
Referring to these Drawings; the nature and novelty of the improvements con-
sist in fitting on the pressure tube G¹ close to the gauge G and between this and
the ordinary siphon tube A³, a two or a three way cock and key A a (or valve) in
place of a single way cock as heretofore, that is having an extra lateral branch
formed at a², with coupling branch A² or with drain tube A", for relieving or
setting on and off the pressure or vacuum on the gauge G, quite over the water
inverted siphon or U pressure pipe A' when that is used, by the turning of the
key a a quarter turn, this being formed also with an extra lateral branch opening
or duct a¹, to effect this relief of the pressure from the gauge G through the new
branches a¹, a². This two or three way cock or valve A a, is for the purposes, in
one position of the key a as dotted-in in Figure 1, and shown in sharp lines in
Figure 4, of drawing off the water or fluid from the acting hollow tube (or vessel,
of the gauge G itself, through the new side openings or branches a¹ a² A³ or A" to
the atmosphere, while shutting the opening a³ leading from the siphon tube A¹ to
the key a and gauge G as shown particularly in Figure 4 and indicated by the
arrows, so as to test the gauge G and see that the pointer g comes back to zero,
agreeing to the pressure of the atmosphere, which would be admitted to the gauge G,
as the water was drawn off, through the branch a², a¹, while preventing the dis-
placement of the water always left in the siphon pipe A¹; and then in the second
position of the key a and its handle all shutting off the said new orifice or branch a¹, a²,.
to the atmosphere as indicated in sharp lines Figures 1 and 2, and opening the
pressure water tube and siphon A¹ to the gauge G letting the water act within the
gauge to indicate the pressure caused in it by the pressure in the siphon pipe A¹,
without allowing the steam or hot vapour to enter the gauge G and heat or strain
it, as has been the case heretofore, when such testing cocks were applied, which
drained off the water or liquid from the siphon A¹ and allowed the hot steam or
vapour to enter the working pressure tube G¹ of the gauge G which is detrimental
to the gauge by straining it under abnormal heat in addition to the pressure only
desired to be indicated. The key a and handle all might have a third position in its
three way cock A, when that is desired, for shutting off the gauge tube G¹, from the
siphon pressure tube A', also from the third or lateral opening to the atmosphere a²
when the gauge G was not desired to be used, or when the water was desired to be
blown off from the siphon tube A¹, to see that it was clear. The outer end of the
key or cock a would be formed with cross lines at a¹¹ indicating the direction of the
passages al a³ through the key a to show the direction of these outside.
When desired a stop might be formed on the key a or cock A, or both, as shown
at A Figure 3, to prevent the key a and handle all being turned to open the siphon
orifice a to the atmospheric orifice a2, and thus prevent the possibility of the
siphon A¹ being emptied of the trapping liquid separating the hot steam or other

page_text: pressure fluid from entering the acting gauge G or pressure indicating vessel. In
some cases an outside drain tube A³, shown in Figure might be fitted with a
coupling A to the lateral branch a leading to the atmosphere to convey the water
away to any convenient place, and prevent it from escaping direct to the atmosphere
as indicated at A" in Figure 4.
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 :-
-;
In fluid pressure and vacuum gauges, the forming and fitting between the gauge
and the siphon tube of a two, or a three-way key and cock, or valve, with branch
leading to the atmosphere, for setting on and off the pressure, or the vacuum in the
gauge, substantially as and in the manner and for the purposes herein described, in
reference to and shown in the accompanying Drawings.
Lindh teil A1000
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.