IMPROVED APPLIANCES TO RAILWAY AND TRAMWAY CARRIAGE GAS HOLDERS, WHEREBY THEY MAY BE AUTOMATI- CALLY CHARGED
Year: 1877

page_text: LETTERS PATENT to James Milne, of Edinburgh, in the County of Edinburgh,
North Britain, for the Invention of "IMPROVED APPLIANCES TO RAILWAY
AND TRAMWAY CARRIAGE GAS HOLDERS, WHEREBY THEY MAY BE AUTOMATI-
CALLY CHARGED
"
PROVISIONAL SPECIFICATION left by the said James Milne at the Office of
the Commissioners of Patents on the 10th May 1877.
"
JAMES MILNE, of Edinburgh, in the County of Edinburgh, North Britain.
IMPROVED APPLIANCES TO RAILWAY AND TRAMWAY CARRIAGE GAS HOLDERS,
WHEREBY THEY MAY BE AUTOMATICALLY CHARGED."
In the supply of gas to railway carriages by what is known as the high-pressure
system a reservoir charged with gas at a pressure of many atmospheres is used, and
from this reservoir the gas flows through a special form of regulator and is reduced
in pressure before reaching the burners. The plans at present adopted are liable to
induce an irregular pressure in the supply of gas to the burners, and it is the object
of the present Invention to provide more certain means for ensuring regularity of
supply. This is effected by causing the gas, which is under a pressure unsuitable
for its proper combustion by such burners as are usually used for lighting by gas, to
flow into a gas holder properly weighted or balanced so that the gas contained in it
shall be compressed only to the extent necessary for the supply of all such burners
in connection with the gas holder at a pressure suitable for burning the gas to the
best advantage. Within this gas holder is fixed an inlet regulating valve so
connected with it as to open when the store of low-pressure gas is diminished and
shut again when the gas holder has been sufficiently refilled from the high-pressure
reservoir.
The gas holder is made in conformity with those described in Specification No.
2842, in reference to Letters Patent granted to William Thomas Sugg, and bearing
date Aumist 12 1875

page_text: The appliance or regulating valve which forms the subject of the present Inven-
tion is made and used in conjunction with the gas holder as follows:-At the
bottom of the gas holder a trough or recess is formed, and at or near the end of the
side of the trough the gas inlet from the reservoir is fixed. The mouth of the inlet
within the gas holder is made internally conical and forms the valve seat. The valve
is made of metal, ivory, bone, or horn, externally conical, and corresponding in size
and shape to the valve seat. The valve is fixed to a metal spindle which is formed
into a single or double-threaded screw at one end, and works through a nut fixed to
the bottom of the gas holder. The other end of the valve spindle passes through a
guide, also fixed to the bottom of the gas holder. Between the nut and the guide is
keyed or fixed a lever, the upper end of which is jointed and attached to the top of
the gas holder, the under side of the lever being furnished with a spring to prevent
the valve from being opened unnecessarily.
The apparatus is used and acts in the following manner:-The reservoir being
charged with gas a tap is turned and the gas allowed to flow into the gas bolder,
which at the commencement is empty and the valve therefore open.
As the gas
holder rises it operates upon the lever, and this in its place actuates the valve
spindle, which being screwed at one end causes the valve to approach its seat, so
that when the gas holder is full, or nearly so, the valve has reached its seat and the
further supply of gas is shut off. When however the gas is turned on to the
burners the gas escapes thereto through the outlet in the gas holder, and the top of
the gas holder falls.
The lowering of the gas holder has of course the opposite action to its rising,
consequently the valve is opened until sufficient gas from the reservoir has been
admitted to refill it. Practically the valve is generally partially open, but so
slightly that only just sufficient gas is allowed to pass as will keep the gas holder
full, the result being that the gas when it reaches the burners will be supplied at a
pressure equal only to that of the gas holder or to whatever it is weighted. By
these means the supply of gas to the burners may be regulated and maintained with
precision.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Milne in the Great Seal Patent Office on the 9th November
1877.
JAMES MILNE, of Edinburgh, in the County of Edinburgh, North Britain.
"IMPROVED APPLIANCES TO RAILWAY AND TRAMWAY CARRIAGE GAS HOLDERS,
WHEREBY THEY MAY BE AUTOMATICALLY CHARGED."
In the supply of gas to railway carriages by what is known as the high-pressure
'system a reservoir charged with gas at a pressure of many atmospheres is used, and
from this reservoir the gas flows through a special form of regulator and is reduced
in pressure before reaching the burners. The plans at present adopted are liable to
induce an irregular pressure in the supply of gas to the burners, and it is the object
of the present Invention to provide more certain means of ensuring regularity of
supply. This is effected by causing the gas, which is under a pressure unsuitable
for its proper combustion by such burners as are usually used for lighting by gas, to
flow into a gas holder properly weighted or balanced so that the gas contained in it
shall be compressed only to the extent necessary for the supply of all such burners
in connection with the gas holder at a pressure suitable for burning the gas to the
best advantage. Within this gas holder is fixed an inlet regulating valve so
connected with it as to open when the store of low-pressure gas is diminished, and
shut again when the gas holder has been sufficiently refilled from the high-pressure
reservoir.

page_text: The gas holder may be made in conformity with those described in Specification
No. 2842 in reference to Letters Patent granted to William Thomas Sugg, and
bearing date August 12, 1875.
The
The appliance or regulating valve which forms the subject of, the present Inven-
tion is made and used in conjunction with the gas holder as follows:-At the
bottom of the gas holder a trough or recess is formed, and at or near the end of the
side of the trough the gas inlet from the reservoir is fixed. The mouth of the inlet
within the gas holder is made internally conical and forms the valve seat.
valve is made of metal, ivory, bone, or horn, externally conical, and corresponding
in size and shape to the valve seat. The valve is fixed to a netal spindle which is
formed into a single or double-threaded screw at one end and works through a nut
fixed to the bottom of the gas holder. At one end of the valve spindle is fixed a
lever slotted at or near its other extremity. This slot receives a pin attached to the
guide tube that is fixed to the upper part of the gas holder. A large special spring
may be placed between the upper and lower parts of the gas holder to prevent the
valve from being opened too suddenly, but in practice it may be found that the oil
supplied to the guide and guide tube may, while it acts as a lubricant, also offer
sufficient resistance to the descent of the gas holder as to render the spring
unnecessary.
In order that the foregoing may be more easily understood, Drawings are attached
hereto of which the following is a description:
Fig. 1 is a side sectional elevation, the arrangement for guiding the gas holder in
its action upon the valve being also shown in section.
Fig. 2 is a part sectional plan of the trough containing the valve.
Fig. 3 is an end elevation of the trough, the internal arrangement being shown in
dotted lines, and Fig. 4 is a plan of the cross bar fixed to the outer case of the gas
holder, and to which is attached the guide rod.
In Fig. 1, A is the outer casing of the gas holder; B, the flexible gas holder; C,
the guide rod; and D, the guide tube which is fixed to the top of the gas holder and
receives the guide rod C. The guide tube is fixed to the gas holder by a nut E,
which has attached to its upper part an oil cup F. The lower part of the guide
tube is provided with a pin G, which works in a slotted hole H of the lever I, the
other end of the said lever being fastened to the multiple-threaded screw valve J,
shown in Fig. 2, the conical point of which enters the gas inlet K, and when closed
rests against the conical seat L. M is the nut through which the screw valve
works, and N, in Figs. 1 and 3, is the gas outlet. In each of the Figures similar
letters refer to the same parts.
The apparatus is used and acts in the following manner:-The reservoir being
charged with gas a tap is turned and the gas allowed to flow by the inlet K into
the gas holder B, which at the commencement is empty and the valve therefore
open. As the gas holder rises it operates upon the lever I, and this in its place
actuates the valve spindle, which being screwed at one end causes the valve J to
approach its seat, so that when the gas holder is full, or nearly so, the valve has
reached its seat and the further supply of gas is shut off. When however the gas is
turned on to the burners, the gas escapes thereto through the outlet N in the gas
holder and the top of the gas holder falls. The lowering of the gas holder has of
course the opposite action to its rising, consequently the valve J is opened until
sufficient gas from the reservoir has been admitted to refill it. Practically the valve
is generally partially open, but so slightly that only just sufficient gas is allowed to
pass as will keep the gas holder full, the result being that the gas when it reaches
the burners will be supplied at a pressure equal only to that of the gas holder or to
whatever it is weighted or adjusted. By these means the supply of gas to the
burners may be regulated and maintained with precision.
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, I would
observe in conclusion that I do not confine or restrict myself to the precise details
or arrangements which I have described or referred to, as variations may be made

page_text: therefrom without deviating from the principles or main features of this Invention ;
but what I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is, the construction
of the screw valve J, seat L, and lever I, as and for the purpose herein set forth, and
arranged as herein described and shown on the Drawings.
In witness whereof, I, the said James Milne, have hereunto set my hand
and seal, this Eighth day of November, in the year of our Lord One
thousand eight hundred and seventy-seven.
JAMES MILNE. (L.S.)