Improvements in Gas and Oil Motor Engines.
Year: 1890

page_text: Date of Application, 27th Mar., 1890
Complete Specification Left, 22nd Dec., 1890-Accepted, 24th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Gas and Oil Motor Engines.
I, Dr. NICOLAUS AUGUST OTTO of Köln in the Empire of Germany, Engineer,
do hereby declare the nature of this invention to be as follows:-
In the gas and oil motor engines working with a cycle of four strokes heretofore
constructed, there has always been employed a countershaft driven through toothed
gearing from the engine shaft at half the speed of the latter, for working the valve
and other gear.
The present invention has for its object to dispense with the said countershaft and
toothed gearing, whereby the motor engine is rendered simpler in construction, and
works more quietly in consequence of the absence of toothed gearing.
If the movement of the discharge valve of the cylinder were effected by the engine
shaft or by a countershaft revolving at the same speed without special appliances, the
discharge valve would be opened both during the discbarging stroke and during the
compressing stroke.
In order to maintain the discharge valve closed during the compressing stroke,
according to the present invention, a suitable apparatus is made to act upon the
discharge valve gear at the proper time, either:
A, by the action of the rarefaction produced in the cylinder during the suction
stroke, or
B, by the action of the pressure produced during the compression or the working
stroke.
I will proceed to describe various arrangements of apparatus for carrying out
these methods of operating.
According to one arrangement operating according to method A, a double ended
lever pivotted to the engine framing or cylinder has its one end connected to an
excentric or crank on the engine shaft, either directly by a rod, or through the
igniting slide of the engine, when such is used, while its other end carries a pivotted
rod that is ordinarily held by a spring against a stop on the lever, so that as the latter
receives a to and fro motion from the excentric, the rod at each forward motion would
butt against the notched end of the stem of the discharge valve, the excentric being
so arranged relatively to the engine crank that such opening of the escape valve takes
place during the instroke of the piston.
The said rod on the reciprocating lever is connected by a link to a flexible
diaphragm closing a cup-shaped vessel which is connected by a small pipe with either
the gas supply pipe or the air inlet of the cylinder. The effect of this arrangement
will be that when the piston is performing its suction stroke, producing a certain
rarefaction in the gas and air supply pipes, this reduction of pressure in being trans-
mitted to the cup will cause its diaphragm to be forced inwards by the excess of
atmospheric pressure, and this will thereby draw the free end of the pivotted rou to
one side, so that when, during the following compressing instroke, the reciprocating
lever moves towards the discharge valve, the pivotted rod will fail to push open the
discharge valve, which will consequently remain closed. The full atmospheric
pressure being meanwhile restored in the gas and air pipes and consequently in the
cup, the diaphragm will move outwards again, thereby permitting the pivotted rod to
resume its original position, so that when the piston commences its expelling stroke
after the working outstroke, the reciprocating lever and its rod in moving forward
again will cause the discharge valve to open.
If the pipe from the cup be connected to a part of the gas supply pipe beyond the
gas valve, then the above described action of the diaphragm in pulling the rod to one
side will only take place when the gas valve is opened, and consequently, when the gas

page_text: supply is stopped owing to the engine running too fast, as is the case with one method
of regulating such engines, the rod will be made to open the discharge valve at such
instroke of the piston, instead of at every alternate instroke, so that the engine will
in that case be ready at the end of every instroke to draw in a fresh explosive charge.
The discharge valve may also be kept open by known means during the outstrokes of
the piston when no explosive charge is being admitted, so as to draw back the hot
combustion gas of the previous explosion.
Instead of actuating the pivotted rod by a flexible diaphragm as described, it may
be connected to a small piston in a cylinder communicating with the air supply pipe,
such piston being made to operate the rod in precisely the same manner as described.
The said rod may also be actuated by the gas or air admission valve or mixing valve.
According to another arrangement adapted for operating according to the method B,
the cup with diaphragm, or cylinder with piston. is made to communicate with the
interior of the working cylinder, instead of with the gas and air supply pipes; the
pivotted rod on the reciprocating lever is so acted upon by a spring as to tend to keep
out of gear with the discharge valve stem, and the connection of the pivotted rod with
the diaphragm or small piston is made with a spring action. By this arrangement,
when pressure exists in the cylinder during either the compressing instroke or the
working outstroke, such pressure causes the diaphragm or small piston to tend to push
the pivotted rod in line with the discharge valve stem, so that during the expelling
stroke following the working stroke, the reciprocating lever with its rod, in moving
inwards, will push the discharge valve open. On the ensuing suction or charging
stroke, the cup or small piston will be subject to the rarefaction existing in the
cylinder and consequently the spring will be free to draw the pivotted rod out of line
with the valve stem, so that at the commencement of the ensuing compressing instroke
the end of the rod will pass by the valve stem, allowing this to remain closed; and
although during the compressing stroke the diaphragm or small piston will tend to
push the pivotted rod in line with the valve stem, it will be unable to do so until the
reciprocating lever has moved backwards again and then advances, that is to say, until
the working stroke has been performed and the expelling stroke has commenced.
Dated this 27th day of March 1890.
ABEL & IMKAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Gas and Oil Motor Engines.
I, Dr. NICOLAUS AUGUST OTTO of Köln in the Empire of Germany, 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:
In the gas and oil motor engines working with a cycle of four strokes hereto-
fore constructed, there has generally been employed a countershaft driven through
toothed gearing from the engine shaft at half the speed of the latter, for working
the valve and other gear.
The present invention has for its object to dispense with the said countershaft
and toothed gearing, whereby the motor engine is rendered simpler in construction,
and works more quietly in consequence of the absence of toothed gearing.
If the movement of the discharge valve of the cylinder were effected by the
engine shaft or by a countershaft revolving at the same speed, without special
appliances, the discharge valve would be opened both during the discharging stroke
and during the compressing stroke.
In order to maintain the discharge valve closed during the compressing stroke,
according to the present invention, a suitable apparatus is made to act upon the
discharge valve gear at the proper time, either:
A, by the action of the rarefaction produced in the cylinder during the suction
stroke, or:

page_text: B by the action of the pressure produced during the compression or the working
strokes.
I will proceed to describe various arrangements of apparatus for carrying out
this method of operating with reference to the accompanying drawings, in which
Fig. 1 shews a longitudinal section of a motor engine with one arrangement of the
said apparatus applied thereto,
Fig. 2 shews a diagram of the crank and eccentric motion,
Fig. 3 shews a view of the valve gear in a different position,
Figs. 4, 5 and 6 are details of the gas and air admission apparatus, and
Figs. 7, 8 and 8 shew other arrangements.
Method A. The crank shaft of the engine Fig. 1 has an excentric a or a crank,
which is placed at an angle of 90° to the engine crank, as at Fig. 2, and from which,
by means of a rod b, an igniting slide 2 is actuated. The igniting device is here
assumed to be a heated tube, but any other known igniting device may be used.
A double-ended lever d is connected at its one end by a link c to the slide = so as
to have a to-and-fro motion imparted to it thereby, and to the other end of the lever
is pivotted a rod or pawl e.
According to the position given to this rod, it will either be made to force open
the discharge valve by bearing against the notched end of its stem during the
forward motion of that end of lever d, or it will miss the end of the valve stem
when brought into the position shewn at Fig. 3, and thus allow the valve to
remain closed. This shifting of the rod e is effected in the present case by the
apparatus 9, consisting of a hollow vessel or cup, closed by an elastic or flexible
diaphragm, which is connected by a link i to the rod e. The cup g is made
to communicate by a pipe k with the air supply at ¹ Fig. 4, or with the gas
pipe at k².
The apparatus operates as follows:-
Assuming the engine to be in regular working, the gas valve being eitner
opened by a known governor arrangement at each forward motion of the piston,
or being always in the open position, and only closed when no explosive mixture
is to be drawn into the cylinder, the admission of gas and air to the cylinder
being controlled by the valve in the well known manner.
At Fig. 6 of the drawing is shewn a known form of inertia governor for the purpose
of acting on the gas valve, the governor being carried by and moving with the
igniting slide z.
When an explosive charge is drawn into the cylinder by the forward motion of the
piston, there will exist in the cylinder and in the gas and air supply pipes a pressure
below that of the atmosphere, and this reduced pressure will be transinitted through
pipe k to the cup g. In consequence hereof the diaphragm will be moved inwards
by the excess of external atmospheric pressure, and the rod e will be drawn thereby
into the position shewn at Fig. 3. On the following inward motion of the piston,
during which the slide will be moved to the left hand, the rod e, in moving forward
with the end of the lever, will consequently miss the stem of the valve f, and will
move past the same, as indicated; consequently the discharge valve will remain
closed, and the cylinder charge will be compressed.
At the following forward stroke of the piston, the explosion and expansion of the
gases will take place. At the ensuing inward stroke, the slide 2 will again move to
the left hand; in the meantime the pressure within the cup 9 will have become equal
to the atmosphere, so that the spring m which acts upon the rod e will draw the latter
back into the position shewn at Fig. 1, so that on the forward motion of the lever d
the rod e will force open the discharge valve.
The above described action will he repeated at every cycle of four strokes.
Instead of the arrangement of cup with flexible diaphragm shewn at Fig. 1, it will
be evident that any equivalent thereof may be used such as a small cylinder with
piston pfitted on the air supply pipe, as shewn at Fig. 7. The rod e can also be
actuated by means of an inlet valve or mixing valve.
If the pipe & of the apparatus g is connected with the air supply pipe k¹ or gas

page_text: supply pipe k², then every time that only air is drawn into the cylinder instead
of an explosive mixture, the diaphragm will come into action, and keep the discharge
valve closed. The known mode of regulating the speed of the engine will then take
place, whereby only air is drawn in, instead of explosive mixture, is compressed and
expanded, and is then discharged.
In order to obtain an increased regularity of motion, the engine can be regulated in
such a manner that the air drawn into the cylinder by the one outstroke, is forced out
again during the following instroke, so that after a single revolution, an explosive
charge can be again drawn in.
This is effected by connecting the pipe k with the gas supply pipe in front of the
gas valve, that is to say, at k³ Fig. 5, so that the diaphragm only operates when an
explosive charge is being drawn in.
With this arrangement, when only air is drawn in, there being no action of h, the
rode will always open the discharge valve at each instroke of the piston, allowing the
charge of air to be expelled
If it be desired to regulate by drawing in not only air but also the previously
expelled combustion gases when the gas supply is cut off, any of the known arrange-
ments for keeping the discharge valve open during the suction stroke may be employed,
so as to draw back the combustion gases through such valve from the escape pipe.
In this case the apparatus y, will not come into action; the discharge valve remains
open during the instroke of the piston, so that the combustion gases drawn in are
expelled again, and as soon as the discharge valve closes, an explosive charge can be
drawn in again.
Method B. Figs. 8a 8b shew an arrangement for the case in which the pressure
produced during the compression stroke or during the working stroke is utilised for
influencing the mechanism actuating the discharge valve. The rod e is acted upon by
spring m which always tends to draw it out of gear with the valve stem, so that on
the forward motion of the lever d, the valve is not opened thereby.
To the rod e is connected a piston n the outer end of which is coned as a valve, so
as to fit on a seating formed in the small cylinder in which it works. Between the
rode and piston n is provided a spring o, and the space in the cylinder behind the
piston n communicates with the engine cylinder, by a small passage.
During the compression stroke the pressure forces the piston n outwards against its
seat, thereby causing the spring o to be compressed; the rod connected therewith can
however not put the rod e in gear with the stem of valve f, as by the motion of the
lever d the rod e will have been moved past the stem. The ensuing pressure due to
the explosion will keep the piston n in the same position, so that when, by the
backward motion of the lever d, the end of the rode has passed the end of the valve
stem, the spring o will move back the rod in line with the stem as at Fig. 8b, so that
when, during the expelling stroke, the igniting slide moves to the left, thereby moving
forward the outer end of lever d, the rod e will force open the discharge valve.
At the following charging stroke the decrease of pressure in the cylinder will allow
the piston n to be forced away from its valve seat by the atmospheric pressure, and by
that of the spring 9 whereupon, the rod e will be drawn out of gear with the valve
stem by the spring m¹.
Instead of the small cylinder with piston n may be employed any other apparatus
that is moved in a similar manner to that above described by the pressure in th
engine cylinder, as for example the apparatus g with flexible diaphragm described
under method A.
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
claim is
-
1. For the purpose of dispensing with the countershaft running at half the speed o
the engine shaft in four-stroke-cycle engines, the method of utilising the decrease o
pressure occurring in the supply pipes or in the cylinder during the suction o
charging stroke, or the increase of pressure occurring in the cylinder durin

page_text: the compression stroke, or working stroke, for influencing mechanism actuated by the
engine shaft and operating the discharge valve, in such manner that during the
instroke of the piston after the charging outstroke, the discharge valve remains closed,
while during the instroke after the working outstroke the said valve is opened.
2. For the purpose of effecting greater regularity of working in engines operating
according to the method referred to in the first claim, the modification of such method
whereby the discharge valve is only closed during the return stroke of the piston when
an explosive charge has been drawn in by the previous outstroke, while when only air,
or air and combustion gases, have been previously drawn in, the discharge valve is
opened during the instroke, so that an explosive charge can be drawn in at the
following outstroke, substantially as described.
3. For carrying out the method of operating set forth in the first claim, the use of a
lever d with pivotted rod e receiving a to and fro motion from the eccentric or crank a
by means of a rod b, so as to effect the opening of the discharge valve f during each
instroke of the piston if the rod e is in position for acting on the stem of the valve,
but which leaves the valve closed when the rod e is moved to one side by a
diaphragm or equivalent appliance actuated by the decrease of pressure during the
suction or charging stroke, substantially as herein described.
4. For carrying out the method of operating set forth in the first claim, the use of
a lever d with pivotted rod e, which receives a to and fro motion from the eccentric
or crank a by means of a rod b, so as to leave the discharge valve closed when the
rod e is kept out of line with the valve stem by means of a spring m', but which is
made to open the valve when the rod e is brought in line with its stem by a piston or
equivalent device acted on by the pressure in the cylinder during the compression or
working strokes, substantially as described.
Dated this 22nd day of December 1890.
ABEL & IMRAY,
Agents for the Applicant.