IMPROVEMENTS IN AND APPERTAINING TO GAS ENGINES, OR ENGINES ACTUATED BY THE EXPLOSION OR COMBUSTION OF MIXED GAS OR VAPOUR AND AIR."
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by James Rhodes at the Office of the
Commissioners of Patents on the 1st December 1881.
JAMES RHODES, of Newton Heath, Manchester, in the County of Lancaster,
Engineer. "IMPROVEMENTS IN AND APPERTAINING TO GAS ENGINES, OR ENGINES
ACTUATED BY THE EXPLOSION OR COMBUSTION OF MIXED GAS OR VAPOUR AND
AIR."
This Invention relates to constructing double acting gas engines, that is to say,
with two cylinders combined in one, and with a piston rod having two pistons, or a
piston to each cylinder; the cylinders are so constructed that both outer
extremities receive the mixture of gas and air or vapour in regulated proportions,
to be therein compressed and exploded, such compression and explosion taking
place at each in and out stroke of the engine. The spaces in the cylinders from
the inside surfaces of the pistons when the pistons are at the outer extremities of
the cylinders form chambers to produce a vacuum so as to exhaust the burnt
gaseous mixtures which pass through valves and pipes into the atmosphere, by
which means I work gas engines with an explosion at both in and out strokes,
producing a great saving in gas and a more powerful engine in a small space.
For this purpose I construct my improved gas engine with a central divisional
casting, in the centre of which I fit a packing gland through which works the
piston rod; this divisional casting may be cast in the centre of a barrel forming
two separate cylinders, or the divisional casting can be fitted in the centre of the
barrel, or two cylinders can be bolted to the divisional casting; the cylinders are
jacketted, leaving spaces for the circulation of water round the cylinder.
The outer ends of the cylinders beyond the working strokes of the engine are
made on the side with chambers, which receive the mixture of gas and air or
vapour and air, to be therein compressed on the return stroke of the in stroke of
the engine of the back cylinder, and on the in stroke of the top cylinder, so that
at every stroke a compression and explosion takes place, in fact working in a
similar manner to an ordinary steam engine. The inside portions of the cylinders
between the divisional casting and the face of the pistons, when the pistons are at
the in strokes, form vacuuin and pressure chambers to exhaust and compress the

page_text: burnt gaseous mixtures a few pounds above atmospheric pressure, enabling the
forcing and escape of such burnt mixtures into the atmosphere.
The engine at one stroke of the piston rod and pistons will be compressing a
regulated mixture of gas and air, or vapour and air ready to be exploded, also
making a vacuum whilst the other piston will expel the burnt gaseous mixture
made by the other cylinder and drawing in a new charge.
Supposing the back piston to have been propelled by an explosion and the piston
to have reached its top stroke, the explosion will have left behind the piston burnt
gaseous mixture under pressure, and at the same time the opposite cylinder forms
a vacuum between the piston and the divisional casting; directly this has taken
place the valve fitted in the box of the inward cylinder is opened by a cam
which is fitted on a shaft and which is actuated by gear; the opposite valve being
opened by the vacuum the burnt mixture passes on from the inward cylinder
through the valve, and through a connecting pipe to and through the opposite
valve to the vacuum formed in the outward or top cylinder; the piston at the
same time the vacuum is formed compresses the mixture of gas and air, or vapour
and air, which when fired forces back the pistons, and the piston of the top
cylinder at the same time compresses the gaseous burnt mixture, closing the
valve and opening a valve fitted in the top of the cylinder or in a box cast on the
top of the divisional casting, forcing out the burnt mixture into the atmosphere;
it will be well understood that each cylinder is constructed in a similar manner
and has similar actions.
The mixture of gas and air or vapour and air is admitted through a slide
valve and expansion valve fitted to each cylinder; the slide valve is made longer
than the expansion valve, and with a longer stroke for the purpose of over-lapping
the ports and closing the feed port, to give only one opening at each revolution;
the slide valves are fitted in the chambers connected with the cylinders and are
kept in working position and face to face through the compression or by the
explosion; the valves are worked by eccentrics fitted on the fly wheel shaft, and
so arranged as to cause an explosion at every stroke of the engine, and the slide
valve for admitting the supply of gas is worked by an eccentric and made to cut
off according to requirement by the action of the governor; this governor is worked
direct from the fly wheel shaft by bevil wheels and shaft; the governor balls
expand and contract, which actuates two small cams and which actuate a small
back valve which is fitted to the gas supply pipe, the governor balls in expanding
cause the cams to contract and cut off the supply of gas, and when the governor
balls fall the supply of gas is given.
The cylinders can be secured on the end of a bed or foundation plate, or the
cylinders can be secured on the top of the foundation plate; the piston rod is
secured in a slide block which works in guides cast or secured to the foundation
plate; a connecting rod is fitted to the slide block which actuates a crank or
cranks made or secured on a shaft.