IMPROVE- MENTS IN AND CONNECTED WITH GAS ENGINES
Year: 1884

page_text: I JOHN HENRY DEWHURST of 169 Grunesthorpe Road, Sheffield in the County
of York Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN AND CONNECTED WITH GAS ENGINES to be as follows:-
This invention consists in making the bottom end of the Cylinder or Cylinders
of an oscillating Gas Engine with a circular recess fitting on to a fixed circular
hollow bearing or journal on which the oscillating cylinder turns, and which forms
the mixing admission and exhaust chambers, the bearing having a partition to
divide the mixing and admission chamber from the exhaust chamber. The end of
the cylinder or cylinders and the hollow bearing are provided with admission and
exhaust porta so arranged that as the cylinder oscillates the admission port is open
when the exhaust port is closed. The admission port or ports in the cylinder aro
fitted with a valve opening into the cylinder which is automatically closed when
the pressure in the cylinder exceeds the external pressure.
Two pipes or chambers one for the admission of air and the other for the
admission of gas, communicate with the mixing chamber and admission port or
ports of the cylinder, and they are each fitted with a valve opening inwards.
The admission ports are arranged so that they close before the charge in the
cylinder is ignited, and pressure thereby created, this is accomplished by disposing the
ports radially in the fixed circular bearing or hollow journal, in such a position that
as soon as the piston has travelled far enough in its forward stroke to admit the
required charge the oscillation of the cylinder closes the admission port in the fixed
bearing, the inlet valve covering the ports and preventing the escape of the gas
from the cylinder into the admission or mixing chamber, The exhaust ports are
so disposed in the fixed hollow bearing and the bottom of the oscillating cylinder
that as soon as the piston has completed its forward stroke the exhaust ports are
open, and they are closed on the completion of the backward stroke of the piston,
An opening is made in the side of the cylinder at a sullicient height from the end
to admit of the required charge of gas and air, this opening is fitted with a valvo
opening inwards and when the piston has travelled up to, and past, this opening,
the flame from a jet of gas which oscillates with the cylinder, and which is kept
burning opposite the said opening, is drawn into the cylinder and ignites the
Γάλα 2,11

page_text: charge therein, thus creating the necessary pressure to force the piston to the end
of its forward stroke and to close the opening by which the flame enters the
cylinder.
The engine is single acting and the piston is carried over the centre by the
momentum of a fly wheel in the ordinary manner.
Gas engines constructed according to my Invention can have one or more
cylinders.
E. EDWARDS HEWETT,
Agent for the Applicant.
COMPLETE SPECIFICATION.
I JOHN HENRY DEWHURST of 169 Grunesthorpe Road, Sheffield in the County
of York, Engineer, do hereby declare the nature of my Invention for "IMPROVE-
MENTS IN AND CONNECTED WITH GAS ENGINES" and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :—
This invention consists in making the bottom end of the cylinder or cylinders
of an oscillating gas engine with a circular recess fitting on to a fixed circular
hollow bearing or journal on which the oscillating cylinder turns and which forms
the mixing, admission, and exhaust chambers, the bearing having a partition to
divide the mixing and admission chambers from the exhaust chamber. The end of
the cylinder or cylinders and the hollow bearing are provided with admission and
exhaust ports, so arranged that as the cylinder oscillates the admission port is open
when the exhaust port is closed. The admission port or ports in the cylinder are
fitted with a valve opening into the cylinder which is automatically closed when
the pressure in the cylinder exceeds the external pressure.
Two pipes or chambers are for the admission of air and gas and to communicate
with the mixing chamber and admission port or ports of the cylinder, and they are
ench fitted with a valve opening inwards.
The admission ports are arranged so that they close before the charge in the
cylinder is ignited and pressure thereby created, this is accomplished by disposing
the ports radially in the fixed circular bearing or hollow journal in such a position
that as soon as the piston has travelled far enough in its forward stroke to admit
the required charge, the oscillation of the cylinder closes the admission ports in the
fixed bearing, the inlet valve covering the ports and preventing the escape of the
gas from the cylinder into the admission or mixing chamber. The exhaust ports
are so disposed in the fixed hollow bearing and the bottom of the oscillating
cylinder that as soon as the piston has completed its forward stroke the exhaust
ports are open and they are closed on the completion of the backward stroke of the
piston. An opening is made in the side of the cylinder at a sufficient height from
the end to admit of the required charge of gas and air; this opening is fitted with
a valve opening inwards, and when the piston has travelled up to and past this
opening the flame from a jet of gas which oscillates with the cylinder, and which

page_text: is kept burning opposite the said opening, is drawn into the cylinder and ignites
the charge therein, thus creating the necessary pressure to force the piston to the
end of its forward stroke and to close the opening by which the flame enters the
cylinder.
The engine is single-acting and the piston is carried over the centre by the
momentum of a fly wheel in the ordinary manner. Gas Engines constructed
according to my Invention can have one or more cylinders.
Fig. 1 is a sectional elevation of my improved gas engine; Fig. 2 is a part side
and sectional elevation of the same. A is the oscillating cylinder; B the piston ;
C the piston rod; D the crank; E-the fly wheel; F the frame or stand, and G the
bottom or foundation plate. The oscillating cylinder A is provided with the loose
bottom H on the underside of which is formed the semi-circular recess bored to fit
and swivel on the fixed circular hollow bearing or journal I, being secured by the
loose semi-circular cap or cover S and the bolts T. The inside of the bearing or
journal I is constructed so as to form the mixing and admission chamber J and the
exhaust chamber K, each being divided by the partition L. In the foundation
plate G is fixed the inlet air valve M, over which is fixed the bottom end of the
mixing or admission chamber J; in the upper end of the latter is fixed the gas
valve N.
When the engine is set in motion atmospheric air is drawn through the valve M
and combustible gas through the valve N into the mixing chamber J, from whence
the explosive mixture passes through the port O in the journal I and the port P in
the cylinder; the ports being full open when the crank is on the bottom centre as
in Fig. 3. The admission port P is fitted with the wing or hinged valve R which
automatically closes when the pressure in the cylinder exceeds the external or the
pressure in the mixing chamber J. As the crank advances the cylinder A oscillates
and closes the admission port O in the fixed journal I before or otherwise the charge
in the cylinder is ignited and pressure generated as in Fig. 1, thereby preventing
the escape of the gas and air or explosive mixture from the cylinder into the
admission or mixing chamber.
On the side of the cylinder is provided the opening V placed at a suitable height
from the bottom of the cylinder or the commencement of the stroke to admit of the
requisite charge of explosive mixture of gas and air, the position being regulated
according to the maximum power the engine is intended to drive. In the opening V
is fixed the conical valve seating W to which is fixed the metallic valve X mounted
loosely on the set screw Y shewn more clearly in Fig. 4: when the piston has
travelled up to and past this opening or otherwise as in Fig. 2, the flame from the
gas jet Z is drawn into the cylinder and ignites the chargo therein, thus creating
the necessary pressure to force the piston to the end of its forward stroko and close
the valve X. The gas jet Z is mounted on a swivel at the bottom end so as to
allow of its oscillating with the cylinder, being held in position by the stay 3.
The engine being single-acting, the piston B is carried over the top centre and
through the remaining part of the revolution by the momentum of the fly wheel E
fixed on the crank shaft; the exhaust being discharged, during the return stroke of
the piston, through the ports 2 which are disposed in the cylinder bottom H and
the fixed journal I so that the exhaust is released when on the top centre or
immediately before as in Fig. 5, which by the oscillation or movement of the
cylinder gradually opens until full open at half stroke as in Fig. 6, after which
point they again gradually close, this being effected when the crank is directly
opposite the point if which they opened.
Fig. 7 is a plan of the journal I showing the admission port O and the exhaust
port 2.
Fig. 8 is a plan through line A, B in Fig. 1, shewing the valve R over the
admission port P, and the exhaust port 2 in the cylinder bottom.
As the combustion of the gases in the interior of the cylinder creates a great
amount of heat it is necessary to cool the same, which is effected by providing the
water jackets 4 as shewn in Figs. 1, 2, 3, 4, 5, 6, 8, and 9; Fig. 9 being a plan of

page_text: the cylinder and jacket with the cylinder cover removed, of which Fig. 10 is a plan
of the cover.
In very small engines made on this principle I may dispense with
the water jacket 4 and substitute the radiating surfaces or wings 6 on the exterior
of the cylinder as shewn in Fig, 11 of which Fig 12 is a plan through line C¹, D¹,
so as to augment the area of the surfaces in contact with the outer atmosphere.
For the purpose of regulation of speed the engine is provided with the governor L'
driven from the crank shaft, and coupled by the adjustable rod 7 to the gas valve N,
which operates as follows:-Suppose a portion of the load is thrown off, the
tendency of the engine is to increase speed with the result of operating the governor
and closing the thoroughfare in the gas valve N so as to diminish the quantity of
gas, consequently reduced power from the explosion through too-great a proportion
of atmospheric air being admitted into the mixing chamber, and vice-versa in case
the load is increased.
Gas Engines constructed according to my invention, although not shewn on the
drawings, can be coupled with two or more cylinders as desired.
Having now particularly described and ascertained tho nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is-
1. The method of opening and closing the admission and exhaust ports by the
oscillating movement of the gas cylinder, substantially as and for the purposes
herein described and shewn.
2. Mounting the gas cylinder on the hollow journal I containing the mixing and
exhaust chambors and the ports O and 2, applied and operating substantially as
herein set forth.
3. Closing the admission ports P by the movement of the gas cylinder before
ignition takes place for the purpose described.
4. The use and construction of the valve R placed inside the cylinder for the
purpose of closing the port P when the internal pressure exceeds the external,
substantially as described and shewn.
5. The general construction and arrangement of an oscillating single-acting gas
engine, wherein the admission and exhaust are effected by the movement of the
cylinder, substantially as described and shewn on the drawings.
Dated this.18th day of December 1884.