Improvements in Engines Worked by Combustible Gases or Vapours, more especially intended for Propelling Vehicles.
Year: 1896

page_text: Date of Application, 4th Mar., 1896
Complete Specification Left, 4th Dec., 1896-Accepted, 23rd Jan:, 1897
PROVISIONAL SPECIFICATION.
Improvements in Engines Worked by Combustible Gases or
Vapours, more especially intended for Propelling Vehicles.
1, FRANCIS HERBERT WENHAM, of The Beacon, near Woking, in the County
of Surrey, Gentleman, do hereby declare. the nature of this invention to be as
follows:-
"
The piston of this engine carries a tubular prolongation which I term a "baffle,"
the external diameter of which, is slightly less than the bore of the cylinder, this
leaves an annular air space which prevents direct conduction of the heat from
combustion to the exterior of the cylinder. The rear cover of the cylinder is
prolonged inwardly as a hollow trunk, the exterior of which enters easily into the
bore of the "baffle." A combustion chamber or tube with its inner end open to
the cylinder is fixed in the trunk, the outer end projecting beyond the cylinder
being enlarged into a box or ignition chamber to which the valves for working the
engine are connected.
'
"
The piston-rod passes through a stuffing box in the forward end of the cylinder
which is utilised as an 'air compression pump with a suction valve and delivery
valve. At the side of the cylinder a compression, tube or reservoir is attached.
During the back stroke of the piston a combustible niixture of air and gas is drawn
into the forward end of the cylinder through the suction valve. This gaseous
mixture is driven into the side tube or reservoir and retained at a considerable
pressure till the piston arrives at the end of the stroke when the retaining valve is
opened and the gaseous mixture rushes into the space. of the ignition box and
combustion chamber and is fired which may be done for example by an electric
spark or the well known ignition tube kept at a red heat. by a lamp. To prevent
the products of combustion returning into the compression tube or reservoir there
is a check valve opening outwards which instantly closes against the higher pressure
arising from the combustion of the gaseous mixture. When the piston reaches the
forward end of the cylinder the exhaust valve is opened and the products of
combustion are discharged by the return stroke. The discharge valve may be
closed shortly before the piston reaches the rear of the cylinder so as to increase
the compression. The engine is single acting giving one impulse. for every
revolution. The object of the "baffle" is to lessen the waste of heat through the
walls of the cylinder, but this conduction of heat may be further diminished by
causing water to circulate round the annular space between the exterior of the
combustion chamber and the interior of the trunk such space being closed water-
tight by a plate attached to the end cover of the cylinder. If this engine be
actuated by petroleum vapour some difference of arrangement is required. Air
only is drawn into the cylinder and forced into the compression tube or reservoir.
The petroleum oil is vaporized by passing through a tube leading from the source
of supply and kept sufficiently heated which may be effected by the same lamp
flame that heats the igniter. The tube finally enters the space between the check
valve and inlet valve on the opening of which the oil vapour mixes with the air
discharged from the reservoir and is then fired and impels the piston. As the oil.
has to be forced against a pressure, either a small pump may be used or the charge
of oil may be carried round by a rotating plug or tap with a cup cavity in the

page_text: barrel which drops a charge of oil into the vaporising tube at each revolution.
To regulate the engine when it runs at an undue speed the supply of oil is stopped
by throwing the rotating plug out of gear by means of a governor which again
connects the feed when the speed falls.
In employing this engine as a petroleum motor for propelling carriages an
oscillating cylinder may be used for the purpose of obtaining compactness. From
the top flange of the cylinder are carried out parallel with the crank shaft two
gudgeons, from these the cylinder together with compression chamber is suspended
in bearings so as to swing freely. The piston rod head is connected directly with
the crank. The opening and closing of the exhaust valve may be effected by the
oscillating movement of the cylinder and the inlet valve be opened at the end of
the stroke by a thrust from a projection from the piston rod head.
Dated this 4th day of March 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Engines Worked by Combustible Gases or
Vapours, more especially intended for Propelling Vehicles.
I, FRANCIS HERBERT WENHAM of The Beacon, near Woking in the County
of Surrey, Gentleman, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :-
I will describe my invention with reference to the accompanying drawing
representing diagrammatically a longitudinal section of so much of an engine as is
necessary to illustrate my invention.
The piston 1 working in the cylinder and connected with the crank shaft
carries a tubular prolongation 2 which I term a." baffle" the external diameter of
which is slightly less than the bore of the cylinder ; so as to leave an annular air
space which prevents direct conduction, to the exterior of the cylinder, of the heat
due to combustion of the gases or vapours. The rear cover. of the cylinder is
prolonged inwardly as a hollow trunk 3 which enters easily into the bore of the
baffle" 2. A combustion chamber or tube 4 with its inner end open to the
cylinder is fixed in the trunk 3 the outer end which projects beyond the cylinder
being enlarged to constitute a box or ignition chamber 5 to which the valves for
working the engine are connected or in which they are contained.
The piston rod passes through a stuffing box in the forward end of the cylinder
which forward end and piston are utilized as an air compression pump the said
forward end being provided with a suction or inlet valve 6 and a delivery valve 7.
At the side of the cylinder a compression tube or reservoir 8 is attached it
'communicating with the forward end of the cylinder and with, the ignition
chamber 5. During the back stroke of the piston a combustible mixture of air
and gas is drawn into the forward end of the cylinder through any suitable inlets
in a chamber or channel surrounding the suction valve 6. This combustible
mixture is driven into the side tube or reservoir 8 and is retained at a considerable
pressure till the piston I arrives at the end of the stroke when the retaining
valve 9 is opened and the gaseous mixture rushes from the side tube or reservoir 8
into the space within the ignition chamber 5 and combustion, chamber 4 and is
fired, which may be done by any suitable means for example by an electric spark
or by the well known ignition tube kept at the requisite heat by a lamp. To
prevent the products of combustion returning into the compression tube or

page_text: reservoir 8 there is a check valve 10. opening outwards which instantly closes
against the higher pressure arising from the combustion of the gaseous.mixture..
When the piston reaches the forward end of the cylinder the exhaust valve 11 is
opened and the products of combustion are discharged by the return stroke of the
piston. The discharge or exhaust valve 11 may be closed shortly before the
piston reaches the rear of the cylinders so as to increase the compression. These
valve .movements. can be! effected by any suitable means such as the well known
cams and rods conveying the motion from the main shaft. The engine is single
acting giving one impulse for every revolution. The object of the baff: 2 is to
lessen the waste of heat by conduction through the walls of the cylinder and this
conduction of heat may be further diminished by causing water to circulate round
the annular space between the exterior of the combustion chamber 4 and the
interior of the trunk 3 such space being closed water-tight by a plate attached to
the end cover of the cylinder. If this engine be actuated by petroleum vapour
some difference of arrangement is required. Air only is drawn into the cylinder
and forced into the compression tube or reservoir 8. The petroleum oil is
vapourized by passing through a chamber or tube 12 leading froin the source of
supply and kept sufficiently heated which may be effected by the same lamp flame
that heats the igniter if a lamp heated igniter be used. The tube 12 finally enters
the ignition chamber 5. On the opening of the inlet valve 9, the oil vapour
mixes with the air discharged from the reservoir 8 and is then fired and impels
the piston forward. As the oil has to be forced against a pressure a small pump
may be used the plunger of which is on the suction stroke drawn by a spring
back against a stop the distance of which is regulated by the governor so that
when the engine runs at too low or too high a speed the supply of oil is increased
or diminished by reason of the governor moving the stop to and fro and so the
feed of oil is diminished or increased according to the speed required.
In employing this engine as a petroleum motor for propelling carriages an
oscillating cylinder may be used for the purpose of obtaining compactness. From
the top flange of the cylinder are carried out, parallel with the crank shaft, two
gudgeons and from these the cylinder (together with the compression chamber) is
suspended in bearings so as to swing freely. The piston rod head is connected
directly with the crank. The opening and closing of the exhaust valve may be
effected by the oscillating movement of the cylinder and the inlet valve be opened
at the end of the stroke by a thrust from a projection from the piston rod head.
If desired the trunk 3 may be omitted as the baffle 2 and the combustion
chamber 4 will in a considerable degree intercept the passage of heat to the outer
wall of the cylinder.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. In engines worked by combustible gases or vapours a "baffle" or tubular
extension from the piston in combination with a trunk or inward extension from
the cylinder cover with the inner end in the cylinder closed and a combustion
tube or chamber with its inner end open to the cylinder substantially as and
for the purpose hereinbefore described and illustrated in the accompanying
drawing.
2. In engines worked by combustible gases or vapours a "baffle" or tubular
extension from the piston in combination with a combustion tube or chamber
projecting from the other end of the cylinder and with its inner end open to the
cylinder substantially as and for the purpose herein before described.
3. In an arrangement according to the preceding claiming clauses an inner
tube or primary combustion chamber with the outer end constituting an ignition
chamber and carrying or containing the working valves and ignition arrangements
substantially as and for the purpose herein before described.

page_text: 4. The general combination and arrangement of parts for engines worked by
combustible gases or vapours as hereinbefore described and illustrated in the
accompanying drawing.
Dated this 4th day of December 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.