Improvements in Two-stroke Gas and Oil Motor Engines.
Year: 1899

page_text: Date of Application, 30th May, 1899
Complete Specification Left, 28th Feb., 1900—Accepted, 30th Aug., 1900
PROVISIONAL SPECIFICATION.
Improvements in Two-stroke Gas and Oil Motor Engines.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad
by Heinrich Eckhardt, of No. 13, Lutzow-fer, Berlin, Germany, Engineer)
to be as follows:
-
In two-stroke cycle gas or oil, motor engines, in which the combustion gases
are cleared out of the working cylinder by means of a charge of compressed air
produced without the use of a special pump, either the front end of the engine
cylinder is utilised as air pump, or the crank shaft is enclosed in an air tight
casing for this purpose. These arrangements have the disadvantage that, on the
one hand, the dead space is very considerable and on the other hand the compressed
air supply comes in contact with the hot outer surface of the engine piston so
that an effectual cooling of the latter by means of cold air is not possible. The
present invention relates to an improved construction of such two-stroke engines
whereby these disadvantages are obviated and which will be described with
reference to the accompanying drawing which shews at Fig. 1 a sectional elevation
of the engine and at Fig. 2 a sectional plan. In this construction the guide A
for the piston rod and connecting rod is constructed as a cylinder to serve as a
clearing air pump in such manner that the crosshead is formed as piston, and
that air is drawn into A through a valve B3 and is forced through valve C into
the air chamber 1) whence, at the required moment, the compressed air is led
through a pipe E into the engine cylinder F.
The front end G of the latter is in constant communication with the outer air
by means of the opening H, so that the piston will be effectually cooled.
With motors of this kind in which for some purpose or other, a supply of
compressed air at higher pressure is required (such as for spraying liquid com-
bustible &c.) a portion of the air forced by the pump A into the chamber ]) can
be led thence into a separate chamber to be there retained at a higher pressure.
This pump chamber is in direct communication with the clearing-out pump so
that the pressure produced in the latter can be directly transferred to the said
chamber.
In those cases where the compressed air stored in the supplemental chamber
requires to be at a very high pressure, the said chamber can be made to constitute
a special small air pump, as shewn at a Fig. 2, which pump then serves, so to
speak, as a second stage of the clearing-out pump, as will he presently described.
The combined action of the two pumps is as follows. The piston of the clearing-
out pump A draws in pure outer air during its outstroke, forces this during
the greater part of its instroke through channel K into the air chamber D
in which the pressure may, for example, be increased to about 05 atmo-
spheres above the atmospheric pressure. At a certain moment the channel K
is closed by a suitable device, so as to stop the supply to the chamber D.
Or. instead of employing a special device for this purpose the closing of
channel K can be effected by the pump piston itself as shewn
drawing. The air still contained in the pump cylinder A after the pistou
on the

page_text: has passed the channel K is forced through the connecting channel binto
the small auxiliary compressing pump a, and in this such air is then still
farther compressed to the required degree by the plunger a. The clearing-out
pump therefore supplies the quantity of air drawn in by it into two separate
collecting chambers of different capacities of which the larger one ]) serves to
receive the clearing-out air supply of low pressure while the smaller one (pump
cylinder a) serves to receive the air to be compressed at a higher degree.
The strokes of the two pump pistons are, however, more or less shifted relatively
to each other, according to the degree of higher pressure required, and the angle
between the two cranks will have to be determined accordingly.
In consequence of the direct connection of the small pump with the clearing-
out pump, the suction valve c of the former takes the place of the discharge valve
of the latter as soon as the piston of A has passed beyond the passage h.
Consequently the suction line of the high pressure indicator diagram of pump a
will coincide with the discharge line of the low pressure diagram of pump A.
Dated this 30th day of May 1899.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Two-stroke Gas and Oil Motor Engines.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad
by Heinrich Eckhardt, of No. 13, Lutzow-tfer, Berlin, Germany, Engineer)
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
In two-stroke cycle gas or oil, motor engines, in which the combustion gases
are cleared out of the working cylinder by means of a charge of compressed air
produced without the use of a special pump, either the front end of the engine
cylinder is utilised as air pump, or the crank shaft is enclosed in an air tight
casing for this purpose. These arrangements have the disadvantage that, on the
one hand, the dead space is very considerable and on the other hand the compressed
air supply comes in contact with the hot outer surface of the engine piston so
that an effectual cooling of the latter by means of cold air is not possible. The
present invention relates to an improved construction of such two-stroke engines
whereby these disadvantages are obviated and which will be described with
reference to the drawing accompanying my Provisional Specification which shews
at Fig. 1a sectional elevation of the engine and at Fig. 2 a sectional plan. In
this construction the guide A for the piston rod and connecting rod is constructed
as a cylinder to serve as a clearing air pump in such manner that the crosshead
is formed as piston, and that air is drawn into A through a valve B and is forced
through valve C into the air chamber whence, at the required moment, the
compressed air is led through a pipe E into the engine cylinder F.
The front end G of the latter is in constant communication with the outer air
by means of the opening H, so that the piston will be effectually cooled.
With motors of this kind in which for some purpose or other, a supply of
compressed air at higher pressure is required (such as for spraying liquid com-
bustible &c.) a portion of the air forced by the pump A into the chamber 1) can
be led thence into a separate chamber to be there retained at a higher pressure.
This pump chamber a is in direct communication with the clearing-out pump
so that the pressure produced in the latter can be directly transferred to the said
chamber a.

page_text: In those cases where the compressed air stored in the supplemental chamber
requires to be at a very high pressure, the said chamber can be made to constitute
a special small air pump, as shewn at a Fig. 2, which pump then serves, so to
speak as a second stage of the clearing-out pump, as will be presently described.
The combined action of the two pumps is as follows. The piston of the clearing-
out pump A draws in pure outer air during its outstroke, forces this during
the greater part of its instroke through channel K into the air chamber D
in which the pressure may, for example, be increased to about 05 atmo-
spheres above the atmospheric pressure. At a certain moment the channel K
is closed by a suitable device so as to stop the supply to the chamber D.
Or. instead of employing a special device for this purpose the closing of
channel K can be effected by the pump piston itself as shewn
drawing. The air still contained in the pump cylinder A after the piston
has passed the channel K is forced through the connecting channel into
the small auxiliary compressing pump a and in this such air is then still
farther compressed to the required degree by the plunger a. The clearing out
pump A therefore supplies the quantity of air drawn in by it into two separate
collecting chambers of different capacities of which the larger one D serves to
receive the clearing-out air supply of low pressure while the smaller one (pump
cylinder a) serves to receive the air to be compressed at a higher degree.
on the
The strokes of the two pump pistons are however, more or less shifted relatively
to each other, according to the degree of higher pressure required, and the angle
between the two cranks will have to be determined accordingly.
In consequence of the direct connection of the small pump with the clearing-
out pump, the suction valve c of the former takes the place of the discharge valve
of the latter as soon as the piston of A has passed beyond the passage h.
Consequently the suction line of the high pressure indicator diagram of pump a
will coincide with the discharge line of the low pressure diagram of pump A.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A two-stroke internal combustion engine wherein the part of the guide A
for the piston rod and connecting rod next the engine cylinder is formed as a
pump for charging the working cylinder and for clearing out the combustion gases
therefrom substantially as described.
2. A two-stroke internal combustion engine wherein a charge of air compressed
by a special charging pump is caused to flow into two separate chambers, for the
purpose of forming two charges of compressed air or gas of different volumes or
of different pressures, of which the one charge serves for clearing out the com-
bustion gases and the other for injecting the combustible charge into the cylinder,
substantially as described.
3. A construction of charging or clearing out pump such as is referred to in
the first and second claims, wherein the air or other gas is first forced from the
pump cylinder A through passage K and valve e into the chamber 1), and the
passage K having been closed by the piston towards the end of the compressing
stroke, the remaining air or gas is forced through a channel into a second chamber
in which it is further compressed by a pumpa, substantially as described.
Dated this 28th day of February 1900.
ABEL & IMRAY,
Agents for the Applicant.