IMPROVED MEANS OF AND APPLIANCES FOR EFFECTING THE AUTOMATIC SEALING OF HYDRAULIC GAS PROVISIONAL SPECIFICATION
Year: 1874

page_text: LETTERS PATENT to Robert May Caffall, of 75, Fleet Street, in the
City of London, and Alfred Thomas, of Alton, in the County of
Hants, Gas Engineer, for the Invention of "IMPROVED MEANS OF AND
APPLIANCES FOR EFFECTING THE AUTOMATIC SEALING OF HYDRAULIC GAS
PROVISIONAL SPECIFICATION left by the said Robert May Caffall
and Alfred Thomas at the Office of the Commissioners of Patents,
with their Petition, on the 5th February 1874.
We, ROBERT MAY CAFFALL, of 75, Fleet Street, in the City of
London, and ALFRED THOMAS, of Alton, in the County of Hants, Gas
Engineer, do hereby declare the nature of the said Invention for
" IMPROVED MEANS OF AND APPLIANCES FOR EFFECTING THE AUTOMATIC SEALING OF
HYDRAULIC GAS MAINS, AND FOR REMOVING THE PRESSURE OF GAS ON RETORTS AT
PLEASURE," to be as follows:-
:―
This Invention relates to improved means of and appliances for
effecting the automatic scaling of hydraulic gas mains and for removing

page_text: the pressure of gas on retorts at pleasure, and consists mainly in an
arrangement and employment of a loose extension portion of pipe below
that known as the dip pipe in the hydraulic main, which extension piece
is capable of being raised and lowered or moved from the outside in any
suitable manner preferably by a rod connecting the extension piece with
a lever. The top of the extension piece of pipe may be flat, recessed,
or chamfered upon its upper edge to meet a corresponding shaped edge
upon the bottom of the dip pipe which is a fixture. There are guides
upon the inside or upon the outside of the extension piece to ensure its
proper action.
The extension piece is open at bottom and is submerged wholly or
partially in the liquid, the back pressure of gas being free to act upon
the large surface of tar in the bydraulic main and force a column of tar
up within the extension piece and up the dip pipe in the usual manner
to a distance corresponding to the back pressure, whatever that
may be.
The bottom of the dip pipe, according to another method, has a
jointed end hinged or formed with a knuckle or a ball joint, so that the
extension picce rises and falls at an angle, which angle extension piece
can be lifted and lowered as desired.
According to the first plan the dip pipe is not within the liquid, there
being a clearance for the passage of gas from the retort between its
lower end and the surface of the liquid.
The loose extension of the dip pipe may be formed of separate picces
with two or more hinged flaps, all of which can be acted upon simul-
taneously to open the passage.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT 30
MAY CAFFALL, of 75, Fleet Street, in the City of London, and ALFRED
THOMAS, of Alton, in the County of Hants, Gas Engineer, send
greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of February in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did for Herself, Her heirs and successors,
give and grant unto us, the said Robert May Caffall and Alfred
Thomas, Her special licence that we, the said Robert May Caffall and
Alfred Thomas, our executors, administrators, and assigns, or such
others as we, the said Robert May Caffall and Alfred Thomas, our
executors, 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 "IMPROVED MEANS OF
AND APPLIANCES FOR EFFECTING THE AUTOMATIC SEALING OF HYDRAULIC GAS
MAINS, AND FOR REMOVING THE PRESSURE OF GAS ON RETORTS AT PLEASURE,"
upon the condition (amongst others) that we, the said Robert May
Caffall and Alfred Thomas, our exccutors or administrators, by an
instrument in writing under our, 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 we, the said Robert May Caffall and Alfred
Thomas, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to
the accompanying Drawings and to the letters and figures marked
thereon, that is to say :-
This Invention relates to improved means of and appliances for effect-
ing the sealing of the dip pipes in hydraulic gas mains, and for removing
the pressure of gas on the retorts at pleasure, and consists in the
arrangement and employment of a dip pipe with a loose extension piece
of pipe, the top edge of which is capable of being raised so as to come
in contact with the lower edge of the dip pipe, or lowered beneath the.
surface of the liquid in the hydraulic. The top of the extension piece
of pipe may be flat, recessed, or chamfered upon its upper edge to meet
a correspondingly shaped edge upon the bottom of the dip pipe, which

page_text: is a fixture. There are guides attached to the inside of the extension
piece which serve to maintain it in its proper relative position to the dip
pipe. Guides may, however, if preferred, be placed on the outside of
the extension piece, and either attached to it or the dip pipe. Both the
dip pipe and the extension piece are open at bottom, and the latter is
wholly or partially submerged in the liquid in the hydraulic, while the
bottom edge of the former just reaches the surface of the liquid, or by
preference is slightly raised above it.
To effect the raising or lowering of the extension piece a rod is
attached thereto and passes through a stuffing box at the top or cap of
the dip pipe. The rod is pivotted to a lever of the third order, the
fulcrum of which is a standard fixed to the cap of the dip pipe.
Another standard on the opposite side acts as a guide to the lever, and
keeps it from swerving unduly when operated upon. The lever has a
rod or chain depending from one of its ends, while the opposite is
furnished with an adjustable counterbalance weight. The rod fastened
to the extension piece is by preference made in two parts attached to
each other by a hook and eye joint. The lever has attached to it a
swivel piece of iron tapped through its centre, and through which the
screwed end of the rod passes, the top end of the rod being squared so
as to admit of the application of a wrench to turn it round. By this
means the extension piece may be adjusted in height or raised so much
as to convert it practically into an ordinary dip pipe.
According to another method the extension piece is formed with a
ball joint pivotted in the middle and furnished with an orifice through
its centre, but at right angles to the direction of its axis. The extension
piece is raised or lowered by a rod, but in this case it is operated upon
by means of a lever of the first order.
By another plan the extension piece may be made in two or more
flaps hinged to the dip pipe, and opened or closed by means of a rod
attached thereto. The opening of the flaps producing a clear gas way,
while the closing of them effects a seal.
In order that the foregoing may be more easily understood Drawings
are attached hereto, of which the following is a description:-Fig. 1
represents the apparatus as made by preference and in section. Fig. 2
shows the arrangement when a ball joint is used, and Fig. 3, when the
extension piece is formed by hinged flaps. In Fig. 1, A is the hydraulic,

page_text: B the dip pipe, and C the extension piece. D, D, are the guides, and
E, E, the rod jointed as shown at or about the point F. G is the
stuffing box, and H the lever pivotted on to its fulcrum or standard I,
the other standard J acting as guide. K is the adjustable counterbalance
weight. L is a portion of the bridge pipe, and M is an overflow for
liquid in the hydraulic, while N is the rod which is pulled by the
attendant whenever the apparatus is to be acted upon.
E, E, the rod jointed as shown at or about the point F. G is the
stuffing box, and H the lever pivotted on to its fulcrum or standard I,
the other standard J acting as guide. K is the adjustable counterbalance
weight. L is a portion of the bridge pipe, and M is an overflow for
liquid in the hydraulic, while N is the rod which is pulled by the
attendant whenever the apparatus is to be acted upon.
In Fig. 2 B is the dip pipe, and C the extension piece with its ball
shaped end O pivotted at P, the extension piece being raised or lowered
by the rod Q.
In Fig. 3 B also represents the dip pipe, and R, R, the flaps of the
extension piccc, which are hinged at S, S, and opened or closed by the
rod E, which is actuated through the intervention of a lever of the third
order, as shown in Fig. 1.
The action of the apparatus is as follows:-When the retort is closed
or in use the different parts of the apparatus appear in the position
exhibited, and permits a free passage for tho gas in the direction of the
arrows, but when the retort is opened for the purpose of discharging, the
attendant unhooks or slacks the rod N, when by the preponderance of
the weight Ķ the extension piece C is raised and brought into contact
with the bottom edge of B, and thus the dip pipe is sealed. In the
event of the failure of part of the apparatus to act, however, all danger
is avoided by having the extension piece open at the bottom, whereby
the dip is merely converted for the time being in its action to one of the
ordinary form.
The action of the forms of apparatus shown in Figs. 2 and 3 are
similar.
Having now described and particularly set forth the nature of this
Invention, and the manner in which the same is or may be used or
carried into effect, we would observe in conclusion that we do not
confine or restrict ourselves to the precise details or arrangements herein
described or referred to, as variations may be made therefrom without
deviating from the principles or main features of this Invention, but
what we consider to be novel and original, and therefore claim as the
Invention secured to us by the herein-before in part recited Letters
Patent is,―

page_text: Firstly. The construction of dip pipes with an extension piece as
described and shown on the Drawings in Figs. 1, 2, and 3.
And, Secondly. In the arrangement of screwed rod, swivel piece, and
lever, whereby the height of the extension piece may be adjusted or
temporarily fixed to the dip pipe.
In witness whereof, we, the said Robert May Caffall and Alfred
Thomas, have hereunto set our hands and seals, this Fifth
day of August, in the year of our Lord One thousand eight
hundred and seventy-four.