Improvements in Gas Motor Engines.
Year: 1894

page_text: Date of Application, 24th May, 1894
Complete Specification Left, 22nd Feb., 1895-Accepted. 23rd Mar.. 1895
PROVISIONAL SPECIFICATION.
Improvements in Gas Motor Engines.
I, HENRY PERCY HOLT, of No. 22 Chancery Lane, in the County of London,
Engineer, do hereby declare the nature of this invention to be as follows:
My invention relates to means of reversing gas motor engines, of economising
lubricant in working them and of preventing the disagreeable odour which
characterises the discharged products of combustion when the cylinder is supplied
with excess of lubricant.
I effect reversal of a gas motor engine in the following manner. The ignition of
the combustible charge in the cylinder being arranged to take place a little before
the crank reaches its back centre, I take advantage of this to effect reversal,
providing stops for driving the eccentrics or cams which work the valves or the
shaft which carries them, so that they shall always be in the right position.
relatively to the crank whether it revolves in the one direction or the other.
I reduce the speed of the engine until the flywheel has not sufficient momentum to
carry the crank over its back centre, and then the effect of ignition before the
crank reaches that centre is to propel the piston in the reverse direction, and the
eccentrics or cams which were driven by one set of stops are now driven by
the other set, being thus turned to suit the reversed movement of the engine. In
cases where there is a reservoir of compressed gas as in gas motor cars, I provide
for starting the main engine in either direction by means of a small engine
employing as working fluid for this engine a portion of the compressed gas, and
collecting the exhaust gas from this engine in a suitable receptacle whence it is drawn
to charge the main engine.
For the purpose of economising lubricant and preventing the disagreeable odour
of the discharged products of combustion when the cylinder is supplied with excess
of lubricant, I connect to the lever or rod which, under control of the governor,
opens the gas supply valve, a lubricating apparatus that may be a wire which
whenever the gas valve is opened dips into an oil receptacle and transfers a portion
of the oil to the lubricator of the cylinder. Or by the opening of the gas valve a
pawl may be moved acting on a ratchet wheel on the spindle of an oil cock, which
after a certain number of charges of gas, admits a certain quantity of lubricant to
the cylinder.
In some engines, a governor is applied to determine the opening of the exhaust
valve when the engine is running at or below normal speed, but to prevent it
from being opened when the speed is excessive. When this arrangement is adopted,
the lubricating apparatus may be worked from the lever or rod which opens the
exhaust valve.
According to a modified arrangement, the aperture for admitting lubricant to the
cylinder is closed by a valve connected to a piston or flexible diaphragm which
covers a chamber communicating with the gas supply pipe. When the combustible
charge is drawn into the cylinder reducing the pressure in the gas pipe, the
diaphragm, being subject to atmospheric pressure on its one side and to the less
pressure in the gas pipe on its other side, inoves so as to open the oil valve to an
extent determined by an adjustable stop. By thus operating the supply of lubricant
in conjunction with that of gas, or in conjunction with discharge of exhaust,
lubricant which would under ordinary circumstances enter the cylinder when no

page_text: combustion takes place in it, is economised, and the accumulation of unnecessary
lubricant in the cylinder is prevented.
Dated this 24th day of May 1894.
ABEL & IMRAY,
Agents for the Applicant.
1, HENRY PERCY HOLT, of No. 22 Chancery Lane, in the County of London,
Engineer, 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 :-
My invention relates to means of reversing gas motor engines, of economising
lubricant in working them and of preventing the disagreeable odour which
characterises the discharged products of combustion when the cylinder is supplied
with excess of lubricant.
I effect reversal of a gas motor engine in the following manner. The ignition of
the combustible charge in the cylinder being arranged to take place a little before
the crank reaches its back centre, I take advantage of this to effect reversal in the
following manner: I reduce the speed of 'the engine until the flywheel has not
sufficient momentum to carry the crank over its back centre, I then introduce a
charge which is compressed and then the effect of ignition before the crank
reaches the back centre is to propel the piston in the reverse direction. In order
that the cams which work the exhaust and supply valves and the ignition apparatus
may occupy positions on the valve countershaft relatively to the crank to suit both
directions of revolution I arrange the valve gear as I shall describe referring to
Figs. 1, 2 and 3 of the accompanying drawings.
Fig. 1 is an end view, Fig. 2 is a side view and Fig. 3 is a plan partly in section
of part of the valve countershaft and gear connected therewith.
E, the valve countershaft which, as usual in gas engines of the Otto cycle, is
driven at half the speed of the crank shaft, carries loose upon it the came which
has on it a lateral projecting tooth e¹. On the shaft E is fixed a boss with a
projecting segment e2. According as the shaft revolves in one direction or the
other, the one or the other face of the segment e² acting against the tooth e¹ drives
the cam e. This cam acting on the rounded end (or it might he on a roller) of the
lever e moves the stem e' of the exhaust valve once in every two revolutions of
the crank shaft of the engine. On the same cam is a protuberance e which moves
the gas supply valve and there is also at a suitable part of the cam a protuberance e
for working the ignition apparatus. As the exhaust valve, the gas supply valve,
and the ignition gear are all of the ordinary kind, details of these are not shewn.
In order to prevent the came from being so loose that it might fall over, a spring e
is arranged to press against a bearing & and so to press the cam e against the
boss e².
In cases where there is a reservoir of compressed gas as in gas motor cars, the
main engine can be started in either direction by means of a small barring engine
worked as a pneumatic engine by a portion of the compressed gas, the exhaust gas
from this engine being collected in a suitable receptacle whence it is drawn to supply
the gas charge of the main engine.
For the purpose of economising lubricant and preventing the disagreeable odour
of the discharged products of combustion when the cylinder is supplied with excess
of lubricant, I connect to the lever or rod which, under control of the governor,
opens the gas supply valve, a lubricating apparatus that may be a wire which
whenever the gas valve is opened dips into an oil receptacle and transfers a portion

page_text: of the oil to the lubricator of the cylinder. Or by the opening of the
gas valve a
pawl may be moved acting on a ratchet wheel on the spindle of an oil cock, which
fter a certain number of charges of gas, admits a certain quantity of lubricant to
the cylinder.
In some engines a governor is applied to determine the opening of the exhaust
valve when the engine is running at or below normal speed, but to prevent it from
being opened when the speed is excessive. When this arrangement is adopted, the
lubricating apparatus may be worked from the lever or rod which opens the
exhaust valve.
According to a modified arrangement, I utilise the reduction of pressure in
the gas supply pipe when gas is drawn into the cylinder to operate lubricating
apparatus which I shall describe referring to Figs. 4, 5 and 6 of the accompanying
drawings. Fig. 4 is a plan, Fig. 5 is a vertical section on the line X X of Fig. 4,
and Fig. 6 is a part vertical section on the line Y Y of Fig. 4, of lubricating
apparatus according to my invention arranged on the horizontal cylinder of a
gas or oil motor engine.
G is a reservoir, preferably glass sided, containing oil, and situated over an
aperture 9 leading into a part of the cylinder where it is never uncovered by the
piston. At the bottom of the reservoir G there is a hole provided with a valve
the stem g of which is connected to a disc g² which operates as a piston and for
which a flexible diaphragm might be substituted.
Above the disc g² there is a chamber connected by a pipe g³ with the pipe which
supplies gas or oil vapour to the cylinder.
Whenever by the suction caused by the charging stroke of the main piston the
pressure in the supply pipe is reduced, the disc grises, raising the valve g' and
thus allowing a little oil to flow past the valve stem into the cylinder. The path
of the oil is surrounded by a glass cylinder g* through which the dropping of the
oil can be seen, so that the attendant can regulate the quantity by means of a
screw g by which the upstroke of the stem g₁ can be adjusted. A small pipe g
admits to the space above the oil sufficient air to maintain downflow of the oil when
the valve is open. Oil is supplied when required by a feeding orifice g' provided
with a cap.
When the speed of the engine is too great, the governor, usually employed,
prevents the opening of the valve by which the gas or oil vapour is supplied,
during a revolution or several revolutions until the speed becomes normal.
While the valve remains closed there is no suction in the supply pipe and
consequently no reduction of pressure above the piston or diaphragm g²; thus the
stem does not rise and no lubricant is supplied to the cylinder, when no
combustion takes place in it.
The stem g' of the oil valve, instead of being connected to a piston or diaphragm
so as to be operated as above described might be mechanically connected to a part,
by the movement of which the speed of the engine is controlled.
By thus determining the supply of lubricant in conjunction with that of gas, or
in conjunction with discharge of exhaust, lubricant which would under ordinary
circumstances enter the cylinder when no combustion takes place in it, is
economised, and the accumulation of unnecessary lubricant in the cylinder is
prevented.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described method of reversing a gas motor engine by providing
that ignition of the cylinder charge shall take place a little before the piston
reaches the end of its compressing back stroke by reducing the speed until the fly
wheel has scarcely sufficient momentum to carry the crank over its back centre,
and by introducing and compressing a charge which being ignited, propels the
piston in the reverse direction.

page_text: 2. In a gas motor car having a reservoir of compressed gas, the herein described
method of starting the main gas engine by working a small barring engine
pneumatically with a portion of the compressed gas, utilising the exhaust gas for
charging the main engine.
3. For adapting a gas motor engine to work in either direction, valve gear
arranged and operating substantially as described with reference to Figs. 1, 2
and 3.
4. Determining the supply of lubricant to the cylinder of a gas motor engine,
by making it depend on the supply of gas to the cylinder, or on the freedom of
discharge of the exhaust, as regulated by the governor, as and for the purposes set
-forth.
1
5. Lubricating apparatus for a gas motor engine arranged and operating
substantially as described with reference to Figs. 4, 5 and 6.
Dated this 22nd day of February 1895.
ABEL & IMRAY,
Agents for the Applicant.