Year: 1886

page_text: I, CARL SCHMIDT, Builder, of 8 Museumplatz, Breslau in the German Empire,
do hereby declare the nature of this invention to be as follows:-
The object of this invention is a mechanism for indicating the escape of gas
from underground gas pipes.
The apparatus consists of a vertical cylindrical iron tube of suitable length open
at both ends. This tube is widened below and carries in its lower part several
lateral slits or openings, it is put into the ground over, and at a little distance
from the underground gas pipe. This tube communicates at its upper end with a
cylindrical receptacle which is connected tightly with the same. This receptacle
is provided with a cover adapted to tightly close the same and carrying in its
centre another small opening which is closed by a second cover The receptacle is
supported by a frame set in the pavement or surface of the ground and accessible
from above by a movable grating or flap.
As the gas pipes lie at different depths from the surface, and the tube must
always lie just above the gas pipe the tube may be made of different lengths
according as required.
In order
When gas escapes from the pipe the gas rises in consequence of its lightness and
expels the air in the tube and receptacle and accumulates in the same.
to allow the air to escape easily, the upper cover is fitted loosely.
The escaping gas which penetrates the earth over the defective gas pipe, enters
the tube through the lateral slits.
If these apparatus are put into the ground at intervals along the gas pipes, when
any apparatus is found to contain gas, it indicates that near that place, gas escapes
from the conduit whereupon the latter can be repaired.
The presence of gas in the apparatus is ascertained by removing the flap and
cover and inserting tightly into the opening a suitable upright tube provided with
a cock and widened at its upper end to allow the inspector to ascertain by smelling,
the presence of gas in the apparatus, or provided with a gas burner, in which case,
a double light wire gauze is inserted below the gas burner, whereby an explosion
in the apparatus is prevented. The presence of gas may also be ascertained by
means of Ansell's gas indicator.

page_text: .
An Apparatus to Ascertain the Escape of Gas from Gas Pipes
under the Ground.
I, CARL SCHMIDT, builder, of 8 Museumsplatz, Breslau in the German Empire
do hereby declare the nature of this invention and in what manner the same is to
be performed to be fully described and ascertained in and by the following
statement:-
This invention relates to a mechanism for indicating the escape of gas from
underground gas pipes and an arrangement for conducting any escaped gas into the
open air.
As shown by the 'accompanying drawings, the apparatus consists of a vertical
cylindrical tube a of suitable length open at both ends. This tube which is
.widened below and provided in its lower part, with several slits or openings o is
put into the ground over, and at a little distance from the underground gas pipe c
The tube a is suspended with its upper extremity a¹ in, and tightly connected to,
the receptacle b by a joint e, and supported by planks . The receptacle b which
terminates in a street grating or flap k, is hermetically closed by the cover d,
supported by a rim f cast on to the receptacle k and provided with a flange and
tightening ring, and also by the cover d¹ by means of the screw closing device's.
Fig. 1 shows the vertical section of the road p. and the street grating or flap k,
the receptacle b and the tube a and the cross section of the gas pipe c lying
thereunder and the longitudinal section of a part of a ventilating pipe y.
Fig. 2 is a plan of the receptacle band a longitudinal section of the ventilating
´pipe y.
Fig. 3 shows the horizontal section of the pipe a near its lower extremity
showing the lateral openings o, 0.
As the gas pipes c lie at different depths from the surface and the tube a must
always lie with its lower open extremity just above the gas pipes c, the length of
the tube a varies according as required.
Gas escaping from the pipes c rises in consequence of its lightness expels the air
contained in the tube a and receptacle 6 and accumulates in the latter. In order
to allow the atmospheric air to escape easily, the upper cover is fitted loosely.
The gas which penetrates the earth over the defective gas pipe enters the tube a
through the lateral slits o o.
Generally the underground pipes sink a little by degrees, the ground above
retaining its position. Thereby a space c¹ is left over the pipe which conducts
the gas escaping from defective pipes to the apparatus.
Such apparatus as shown by Fig. 1 are put into the ground at intervals along
the gas pipes, above the joints When any apparatus is found to contain gas it
indicates, that near that place gas escapes from the pipe, whereupon the latter can
be repaired.
The presence of gas in the apparatus is ascertained by opening the flap k¹ and
the cover d' and inserting tightly into the opening g. a suitable upright tube
provided with a cock h Fig. 4 and widened at its upper end to allow the inspector

page_text: to ascertain by smelling the presence of gas in the apparatus; or provided with a
gas burner n, in which case a double piece of fine wire gauze is inserted below the
gas burner n whereby an explosion in the apparatus is prevented. The presence
of gas may also be ascertained by means of Ansell's gas indicator. Besides these
examining methods the presence of gas in the receptacle b is distinctly indicated
by paper saturated with chloride of palladium, which suspended for a short time
through the opening g. in the receptacle 6 Any gas present acts on this saturated
paper the more or less dark colouring of the paper shews with great distinctness
the larger or smaller quantity of gas contained in the receptacle b.
As the indicator suspended in the ground casing is liable to be lowered with the
sinking of the pavement, the bottom opening of the tube a may by degrees be
filled with earth, also earth is liable to fall into the tube a through the openings o o
of the same.
As thereby the working of the apparatus is impaired the cover d is
removed when inspecting the apparatus and the tube a is freed from any earth
contained in it.
To put the indicator into the ground of paved streets, the receptacle 6 the upper
part of which terminates in a street flap k is set tightly into the pavement and
subsequently a hole is bored with a suitable bore through the bottom of the
receptacle down to the gas pipe and the tubes a² a are suspended in this hole.
Besides its purpose as indicator it is intended to serve also to conduct the
accumulated gas through an underground pipe into the higher regions of the air.
For this purpose a tube y is led from the receptacle b through the opening q¹
into the foot of the nearest lamp post, which, being hollow and open at the top,
allows the gases to escape into the upper air. Or special ventilation pipes may be
erected against walls or houses for the same purpose.
While the apparatus is tested for gas the flap t must he closed (Figs. 1 and 2) to
retain the gas rising in the receptacle and so enable its presence to be more easily
ascertained.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is ;-
1. A gas indicator, consisting of the receptacle b the upper part of which
terminates in a street flap k and which is hermetically closed towards the top by
the covers d and d¹ by means of the screw devices; the tube a provided with
slits o, o. and widened at its lower end; and the tube shown by Fig. 4 with
exchangeable end pieces n and m, and allowing the gas pipes to be tested for
escape of gas, by receiving part of the escaped gas in the manner described and
illustrated the presence of gas being ascertained by smelling or lighting or still
more distinctly by means of paper saturated with a solution of chloride of
palladium.
2. The means for continual ventilation of the ground by the said indicator
consisting of the ventilation pipe y. leading from receptacle b through the
opening to the nearest lamp post or other suitable ventilation pipe whereby the
gas contained in the ground, or escaping from the under ground gas pipes is led
direct to an upper stratum of the atmosphere.