IMPROVEMENTS IN MOTIVE-POWER ENGINES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by William Foulis at the Office of the
Commissioners of Patents on the 15th November 1878.
WILLIAM FOULIS, of Glasgow, in the County of Lanark, North Britain, Civil
Engineer. "IMPROVEMENTS IN MOTIVE-POWER ENGINES."
This Invention, which relates to improvements in motive-power engines, has
reference to that class of such engines wherein the motive force is developed by the
combustion of gas or hydrocarbon vapours, and it has for its objects, first, to
operate such engines by pressure constantly applied throughout or nearly through-
out the active stroke of the piston thereof, thereby getting rid of that "negative
action" by which certain kinds of gas engines have been hitherto operated; and,
secondly, to utilize to a further extent than hitherto the heat developed by the
combustion of the gas or hydrocarbon vapour.
In an engine constructed according to this Invention, two, three, or more single
acting cylinders and pistons connected to a crank shaft are employed.
One side of each piston is provided with a trunk or with a thick piston rod in
order to reduce the capacity of the annular space situated between the trunks or
piston rods and the interior of the cylinders. The pistons and cranks are so
arranged as to cause one or more of them to approach the termination of its or their
acting stroke whilst one or more of the other pistons is or are in or about the
position to commence an active stroke. The engines are provided with valves, by
preference of a cylindrical form as hereinafter more fully described, and wherein the
ports are so arranged as to admit of the charge of gas at the commencement of each
piston's acting stroke, after which the port therein by which such gas is admitted is
closed, and another port for admitting compressed and heated air or a mixture of
gas and air is opened simultaneously, with which the charge is ignited and
continues to burn gradually. The air or mixture of gas and air so used is drawn
into the cylinder during the inactive stroke of the piston, and on that side of the
piston on which the gas does not operate, and is compressed on the return, that is
to say, acting stroke, at the same time it becomes heated by taking up a portion of

page_text: the heat developed in the cylinder by the combustion of the gas and air, or mixture
of gas and air, during the active stroke of the piston.
The improved valves for admitting at the proper times the charge of gas and
air, or mixed gas and air, consist of a cylindrical body which is rotated from the
engines, and contained inside a cylindrical casing wherein are the " ways" or
passages leading into the cylinder of the engine. Each valve has in it five ports,
three of which are so situated as to admit of the gas and air or mixed gas and air
on the acting side of the piston, and to discharge the products of their combustion,
the other two ports therein being so placed as to allow of air or mixed gas and air
to be drawn in and discharged from the other side of the piston.
The air or mixture of gas and air being as hereinbefore mentioned drawn in
during the inactive stroke, the port by which it entered is then closed, and towards
the termination of the acting stroke the rotation of the valve opens another port
for admitting the compressed air or mixture of gas and air into another cylinder.
This valve is or may be made tight by packing round the ports, so as to allow of
its expansion on becoming heated.
It is to be understood that the improved valve is not limited in its application to
the precise arrangement of engines herein before described, but it may be used in
other kinds of gas or combustible vapour engines, and the number of ports then
varied according to the arrangement of such engine.
In the case of working the engine herein before described by hydro-carbon, the
liquid is admitted into the cylinders in small quantities by that port of the valve
which corresponds to the gas admission port, and is by the heat of the cylinder
immediately converted into vapour, or such liquid may be injected thereinto."