IMPROVEMENTS IN OBTAINING AND APPLYING MOTIVE POWER, AND THE CONSTRUCTION OF APPARATUS FOR SUCH PURPOSE
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by John Leigh and James Hampson
Gartside at the Office of the Commissioners of Patents on the 5th April
1879. (A communication from abroad by Samuel Marsh, of Calais, France.)
JOHN LEIGH and JAMES HAMPSON GARTSIDE, both of Manchester, in the County
of Lancaster. "IMPROVEMENTS IN OBTAINING AND APPLYING MOTIVE POWER, AND
THE CONSTRUCTION OF APPARATUS FOR SUCH PURPOSE." (A communication from
abroad by Samuel Marsh, of Calais, France.)
This Invention relates to a method of obtaining and applying motive power for
propelling tramway cars, railway trains, ships, and other vessels, or machinery in
general, and for other purposes where a motive power is required, the principal
novel feature of the Invention being the method of and apparatus for obtaining
compressed air at a very much higher pressure than has hitherto been obtained, and
the utilization of such highly compressed air for driving and propelling machinery
of various kinds.
The inventor has discovered that by combining water with the air or saturating it
with moisture so as to form a sort of cold steam or vapour, the said air can be
condensed to a much greater pressure than heretofore, that is to say, to a pressure
of several thousand pounds to a square inch, and by utilizing this highly compressed
air to drive machinery in the manner hereinafter described a very economical and
efficient motive power can be obtained.
For the purpose of compressing the air in the first instance it is proposed to use
a set of pumps somewhat similar to those described in the Specification of Letters
Patent granted to the said Samuel Marsh, and dated 22nd December 1876,
No. 4949, but with the following alterations or improvements:-The valve of the
pump is made in the form of a thimble with a spiral spring inside, a stud projecting
from the end of the thimble through the opening in the valve seating, and touching
(or nearly so) the lower end of the ram. By these means the valve is more efficient
in its action, and little or no air is left in the cylinder after each stroke. Just
below the lower end of the ram when at the highest point of its stroke an opening
is made in the pump cylinder communicating with a channel outside the cylinder
in connection with a water supply, so that at each backward stroke of the ram a
small quantity of water is drawn into the cylinder so as to saturate the air with
moisture, giving it greater density and more power to overcome the back pressure
Pin 971

page_text: of the valve, so that it can be compressed to a much greater degree than air in the
ordinary dry state is capable of.
The vaporized air is to be compressed by these pumps into a reservoir of great
strength, and from this reservoir it is allowed to escape in small jets at a time or in
a continuous current (by means of a suitable valve or tap) through a series of small
bore pipes into a vessel or receptacle.
This vessel or receptacle, or the pipes (or both) being heated by gas, paraffin, or
.other oily substances, charcoal, wood, or other suitable fuel, the small quantity of
highly compressed and vaporized air admitted becomes immediately expanded to
an enormous extent, and the highly elastic vapor thus produced is utilized as a
motive power to drive an air engine for any required purpose. Each jet of com-
pressed vaporized air when expanded by heat is more than sufficient to cause one
stroke of the engine, the motion of the piston being caused to act on the valve
or tap.
The pumps (which require a very small amount of power) may be driven either
by hand or otherwise.
For underground haulage in coal and iron-stone or other mines, pits, or tunnelling
where fire is dangerous or otherwise objectionable, it may be preferable to use the
vaporized compressed air in a cold state. In such cases the compressed vaporized
air is taken direct from the reservoirs to work the engine at such high pressure as
may be decided to use, the receiver or reservoirs being charged as required by
means of the pumps for compressing and forming the vaporized air.
For tramway cars for short journeys one reservoir may be used for the whole
journey and recharged at the end or exchanged for a charged reservoir, so that
there will be no occasion to carry the pumps; and for longer journeys more than
one reservoir may be carried, or stations may be arranged for charging or changing
the reservoirs.
For working railway engines or vessels or for continuous driving of machinery
the pumps must be permanently attached and kept continuously or intermittently
at work (either by hand or otherwise) to keep up a continuous supply of vaporized
compressed air.