Year: 1887

page_text: Date of Application, 23rd Sept., 1887
Complete Left, 14th Apr., 1888
Complete Accepted, 18th May, 1888
I SAMUEL HARRISON of 9 Slater Street, Pendleton in the borough of Salford, in
the County of Lancaster, foreman meter fixer and JOHN TOMLINSON SHEARD of
812 Oldham Road in the local board district of Newton Heath, in the county of
Lancaster, Gas Works Chemist do hereby declare the nature of this invention to
be as follows:-
Our invention relates to the testing of gas pipes and fittings for the purpose of
ascertaining whether they are tight or whether leakages occur and consists in an
improved apparatus for this purpose.
The apparatus consists of an air compressing pump in combination with a mercurial
pressure gauge so arranged that the gauge may be placed or carried in any position
without the mercury being lost out of it. The air compressing pump may be of any
ordinary suitable construction. By preference we use a cylinder open at the top and
fitted with a piston or bucket having an inverted valve in it, the piston being
attached to a rod with a handle at the top for working it. To the cylinder bottom
a pipe with a cock in it is attached, this pipe being connected to another pipe com-
municating with the pressure gauge, which may also have a cock below the gauge.
One of said pipes is arranged to be screwed upon or connected to the gas pipes to be
tested.
The mercurial pressure gauge consists of a hollow iron casing formed with a port
or passage extending from the top of the casing to the underside where the pipe
hereinbefore described is attached, and communicating with the same. To the top
side of the casing we cast or fix a cylinder open at the bottom and descending to a
short distance from the bottom of the casing. The latter is filled with mercury to
above the open bottom end of the cylinder when the gauge is placed upright. Into
the cylinder we place a float swimming on the mercury and attach to it a rod
passing through the top of the casing and having a rack on it outside which gears
with a small spur wheel on a shaft carrying a pointer in front of a dial plate. The
pinion we make of such size that when the float moves about half an inch the
pointer travels round the dial. The capacities of the cylinder and casing are

page_text: such that when the gauge is laid on any of its sides, the cylinder is emptied of the
mercury so that the latter cannot escape through the opening made in the top of
the cylinder for the passage of the rod attached to the float in whatever position
the gauge should be placed into.
The method of using the apparatus is as follows: Supposing the service piping
and fittings of a house to be tested, the apparatus is fixed upon or put into com-
munication with any part of the piping, and the communication of the latter with
the main cut off by the stop cock. Air is then pumped into the piping by means
of the air compressing pump, the cock below the cylinder being closed during the
upstroke and opened during the downstroke of the piston or bucket. This is
continued till the pressure in the piping has reached about twelve inches of water
pressure or half an inch of mercury. This pressure is transmitted through the pipe
communicating with the mercurial pressure gauge to the air contained in the casing,
which depresses the mercury in the latter and causes it to rise inside the cylinder
and lift the float, the rise of the latter and corresponding pressure being indicated
on the dial. After the desired pressure has been obtained, the cock leading to the
air pump is closed and the apparatus allowed to stand.
If the service pipes and fittings are tight, the pressure in the pipes and gauge will
be maintained and the pointer remain at rest, while if leakage occurs the pressure
will decrease and the pointer indicate this decrease. By testing separate lengths or
sealing the fittings in succession the locality of the leakage can be discovered. The
gauge may be fitted with a cock for letting out the pressure after the tests are
completed.
Dated the 22nd day of September 1887.

page_text: COMPLETE SPECIFICATION.
Improved Apparatus for Testing Gas-pipes and Fittings.
We SAMUEL HARRISON of 9 Slater Street Pendleton in the borough of Salford in
the county of Lancaster, Foreman Meter-Fixer, and JOHN TOMLINSON SHEARD of
812 Oldham Road in the local board district of Newton Heath in the county of
Lancaster, Gas-Works Chemist, 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 :—
Our invention relates to the testing of gas-pipes and fittings for the purpose of
ascertaining whether they are tight or whether leakages occur and consists in
improved apparatus for this purpose.
The apparatus consists of an air-pump in combination with a mercurial pressure-
gauge so arranged that the gauge inay be placed or carried in any position without
the mercury being lost out of it.
Reference is to be had to the accompanying drawings, forming part of this
specification, in which similar letters indicate corresponding parts in all the figures.
'
Figure 1 is an elevation of the air-pump in combination with the mercurial
pressure-gauge. Figure 2 is an elevation Figure 3 a plan Figure 4 a longi-
tudinal section on line a band Figure 5 a sectional plan on line c d of the
mercurial pressure-gauge, shown full size, with the pointer and dial plate removed.
The air-pump may be of any ordinary suitable construction. Such a pump is
shown at A in Figure 1 and consists of a cylinder open at the top and fitted with a
piston or bucket having in it a valve opening downwards, the piston being attached to
a rod with a handle at the top for working it, and in the lower part of the cylinder
another similar valve is fitted. To the bottom of the pump a pipe B with a cock in it
is attached, this pipe being connected to another pipe C communicating with the
pressure gauge D and which may likewise have a cock below the gauge. One of said
pipes is arranged to be screwed upon or connected to the gas pipes to be tested.
The mercurial pressure-gauge consists of a hollow iron casing E to the top side of
which we attach or fix a cylinder F open at the bottom and descending to a short
distance from the bottom of the casing. The latter is filled with mercury, as shown
at e, to above the open bottom end of the cylinder when the gauge is placed upright.
We conduct the air or gas supply into the interior of the casing by means of a port or
passage G connected on the inside of the casing to a pipe H which may be on either
the top bottom or side of the interior of the casing (by preference we cast or fix it on
the bottom) and which extends to such a distance within the interior of the casing
that its open end is above the level of the mercury in whatever position the gauge
may be held. The diameter of of the cylinder and of the casing respectively are so
proportioned that the surface area of mercury exposed in the former bears a definite
and known ratio to that in the latter, by preference we make it as 1 to 3. Into the
cylinder we place a float I swimming on the mercury and attach to it a rod passing
through the top of the casing and having a rack J on it outside which gears with a
small spur
wheel or pinion K on a shaft L carrying a pointer in front of a dial plate.

page_text: Instead of the rack and pinion a rod and friction wheel or a counterbalanced cord or
chain passing over a grooved pulley or any other suitable inechanism may be
employed but we prefer a rack and pinion as being more certain in its operation
and less liable to get out of order. We make the top of the casing whore the
float rod passes through it in the form of an inverted truncated cone M projecting
into the interior of the cylinder so that when the gauge is turned upside down no
mercury is lost out of the opening. The toothed gearing of the rack and pinion
we adjust so that the movement of the float in the cylinder is made to show on
the dial the total amount of pressure to which the mercury in the gauge is subjected.
When the area of mercury within and that without the cylinder are in the pro-
portions stated, that namely of 1 to 3, the float will move three quarters of an inch
for every inch pressure on the gauge.
The method of using the apparatus is as follows:-
Supposing the service-pipe and fittings of a house to be tested the apparatus is fixed
upon or put into communication with any part of the piping and the communication
of the latter with the main cut off by the stop-cock. Air is then pumped into the
piping by means of the air-pump until the pressure in the piping has reached about
12. inches of water pressure or nearly an inch of mercury. This pressure is trans-
mitted through the pipe communicating with the mercurial pressure-gauge to the air
contained in the casing and depresses the level of the mercury to which it is exposed
at the same time causing that within the cylinder to be elevated, which raises the float
attached to the rack and this latter actuating the pinion into which it gears causes the
pointer to move in front of the dial to a distance corresponding with the exact amount
of pressure to which the mercury is subjected. After the desired pressure has been
obtained the cock leading to the air-pump is closed and the apparatus allowed to stand.
If the service-pipe and fittings are tight the pressure in the pipes and gauge will be
maintained and the pointer remain at rest, while if leakage occurs the pressure will
decrease and the pointer indicate this decrease. By taking separate lengths or sealing
the fittings in succession the locality of the leakage can be discovered. The gauge
may be fitted with a cock N for letting out the pressure after the tests are completed.
Instead of pumping air into the piping, the air or gas contained in it may be
exhausted by means of a pump having valves opening upwards, the operation being
conducted in other respects in a similar manner to that described. An exhaust or
minus pressure in the piping will be indicated on the dial by the pointer moving in
the reverse direction to that caused by pressure, because in that case the level of
the mercury within the cylinder is depressed while that without the cylinder is
elévated.
Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is
1. The combination of an air-pump with a mercurial pressure-gauge constructed
substantially as described in this specification, and their employment for the purpose
of testing the soundness of, and if unsound of discovering leakages in, pipes and
fittings in the manner substantially as herein shown and described.
2. The construction of a mercurial pressure-gauge adaptable for indicating either
pressure or exhaust in which the rise or fall of the mercury actuates through
the medium of a float and suitable connecting gear a pointer in front of a dial
substantially as herein shown and described.
Dated this 12th day of Anril 1888
SAMUEL HARRISON.
JOHN T. SHEARD.