IMPROVEMENTS IN GAS ENGINES
Year: 1876

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth & Company, Patent
Agency, of Frankfort-on-the-Main, in the Empire of Germany, for the Inven-
tion of "IMPROVEMENTS IN GAS ENGINES." A communication from the Machines
Manufacturing Company "Humboldt," of Kalk, near Cologne, in the Empire
of Germanv.
Sealed the 23rd September 1876, and dated the 10th April 1876.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office of
the Commissioners of Patents on the 10th April 1876.
FRANK WIRTH, of the Firm of Wirth & Company, Patent Agency, of Frankfort-
on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN GAS ENGINES." A
communication.
This Invention relates to engines for obtaining motive power from the explosive
combustion of gas and air without noise at a slight cost, and which are simple of
construction and capaple of easy repair. I employ an elongated cylinder open at
one end, which is provided with two pistons. The one which may be termed the
working piston is connected in the usual way to a crank on the main shaft, which
is provided with a fly wheel. The other piston, which may be termed the loose
piston, has a rod passing through the cylinder cover and through two friction cheeks
mounted on levers in such a manner that they admit of the free movement of the
piston rod in the one direction, but its movement in the opposite direction is stopped
by its causing the cheeks to embrace the rod tightly until the cheeks are relieved
by the action of an eccentric at a certain point in each revolution of the crank shaft.
At the side of the cylinder near the middle of its length is an opening fitted with a
slide, which is worked by a cam on the crank shaft. In this slide, which may be
termed the gas slide, and in its jacket are provided passages for the ingress and
mixture of air and inflammable gas, and of a kindling flame. On the opposite side,
and fixed somewhat higher up, is an opening from the cylinder provided with a
valve opening outwards for the discharge of the products of combustion.
The operation of this engine is as follows:-Assuming that the working piston is
at the extremity of its stroke inwards, the loose piston being close to it, the former
by the rotation of the crank is drawn outwards, and the loose piston having on its

page_text: opposite side the pressure of the air entering by the top, follows the working piston
till it is stopped by a cross head on its rod meeting buffers provided on the cylinder
cover. The working piston continuing its movement creates a partial vacuum
behind it in the space between it and the loose piston. The cam having moved the
gas slide so as to admit into this space the mixture of air and gas, admits the
kindling flame whereby the mixture is exploded.
The pressure produced by the explosion drives forward the working piston, and
at the same time causes the loose piston to make a rapid stroke in the opposite
direction, the air in the space beyond it being discharged through the space in the
head plate. When the projecting upper head of the loose piston closes this space,
the remaining air slowly escaping by a spring valve serves as a cushion to arrest its
movement. The working piston having made its outward stroke, and the loose
piston having also made its outward stroke, and the gas slide having been closed, the
space in the cylinder between the two pistons remains charged with the products of
combustion at a pressure considerably below that of the atmosphere. The atmo-
spheric pressure therefore tends to force both pistons inwards. The working piston
moves inwards in obedience to this pressure, but the loose piston is held near the
extremity of its outward stroke by the aforesaid friction cheeks.
When the working piston is approaching the extremity of its inward stroke the
friction cheeks are slackened off the rod of the loose piston by the action of the
eccentric, and the air slide is opened. The loose piston thereupon makes a rapid
stroke inwards till it nearly meets the working piston, and the products of com-
bustion thus compressed between the two pistons are forced out by the discharge
valve on the side of the cylinder. The action is then repeated.
By placing the cylinder in an upright position the weight of the working piston
is made available to assist its outward stroke, and the weight of the loose piston to
assist its inward stroke.
From the above description it will be seen that the said engine.is double acting, a
portion of the outward stroke of the working piston being effected by the pressure
of the explosion, and its inward stroke by the excess of the atmospheric pressure
over that of the products of combustion. Two or more of such engines may be so
connected to one shaft, as to prevent or diminish irregularity of action.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frank Wirth in the Great Seal Patent Office on the 6th October
1876.
A
FRANK WIRTH, of the Firm of Wirth and Company, Patent Agency, of Frankfort-
on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN GAS ENGINES."
communication from the Machines Manufacturing Company "Humboldt,”" of Kalk,
near Cologne, in the Empire of Germany.
This Invention relates to engines for obtaining motive power from the explosive
combustion of gas and air, without noise, at slight cost, and which are simple of
construction and capable of easy repair. An elongated cylinder, open at one end,
is provided with two pistons. The one which may be termed the working piston
is connected in the usual way to a crank on the main shaft, which is provided
with a fly wheel. The other piston, which may be termed the loose piston, has a
rod passing through the cylinder cover and through two friction cheeks, mounted
on levers in such a manner that they admit of the free movement of the piston
rod in the one direction, but its movement in the opposite direction is stopped by
its causing the cheeks to embrace the rod tightly until the cheeks are relieved by
the action of an excentric at a certain point in each revolution of the crank shaft.
At the side of the cylinder, near the middle of its length, is an opening fitted with
a slide, which is worked by a cam on the crank shaft. In this slide, which may

page_text: be termed the gas slide and its jacket, are provided passages for the ingress and,
mixture of air and inflammable gas and of a kindling flame. On the other side,
and somewhat higher up, is an opening from the cylinder provided with a valve
opening outwards for the discharge of the products of combustion.
The operation of the engine is as follows:-Assuming that the working piston
is at the extreme of its stroke inwards, the loose piston being close to it, the former
by the rotation of the crank is drawn outwards and the loose piston having on its
opposite side the pressure of the air entering by the top follows the working piston
till it is stopped by a cross head on its rod meeting buffers provided on the cylinder
cover. The working piston continuing its movement creates a partial vacuum
behind it in the space between it and the loose piston. The cam having moved
the gas slide so as to admit into this space the mixture of air and gas admits the
kindling flame whereby the mixture is exploded.
The pressure produced by the explosion forces onward the working piston and
at the same time causes the loose piston to make a rapid stroke in the opposite
direction, the air in the space beyond it being discharged through an opening in
the head plate of the cylinder. When the projecting upper head of the loose piston
enters and closes this space the remaining air slowly escaping by a spring valvo.
serves as a cushion to arrest its movement. The working piston having made its
outward stroke, and the loose piston having also made its outward stroke, and
the gas slide having closed the space in the cylinder between the two pistons,
remains charged with the products of combustion at a pressure considerably below
that of the atmosphere. The atmospheric pressure therefore tends to force both
pistons inwards. The working piston moves inwards in obedience to this pressure,
but the loose piston is held near the extreme of its out stroke by the friction cheek
above referred to, the ingress of air beyond it being prevented.
When the working piston is approaching the extremity of its in stroke the
friction cheeks are slackened off the rod of the loose piston by the action of the
excentric, and the air slide is opened. The loose piston thereupon makes a rapid,
stroke inwards till it nearly meets the working piston, and the products of com-
bustion thus compressed between the two pistons are forced out by the dischargo
valve on the side of the cylinder; the action is then repeated.
By placing the cylinder in an upright position the weight of the working piston
is made available to assist its out stroke, and the weight of the loose piston to assist
its in stroke.
From the above description it will be seen that the engine is double acting, a
portion of the out stroke of the working piston being effected by the pressure of
the explosion, and its in stroke by the excess of the atmospheric pressure over that
of the products of combustion. Two or more of such engines may be connected to
one shaft so as to diminish irregularities of action.
DESCRIPTION OF THE DRAWING.
Figures 1 and 2 represent vertical sections of an engine constructed according
to this Invention. B is the cylinder fitted with the working piston H and the
upper piston D, the former being connected by a connecting rod to the crank K on
the fly wheel shaft below; on this shaft is the cam O which works the gas slide D¹
and the cam O¹ which releases the clamp of the upper piston rod. The slide D¹ has
in it a cavity p and a sloped passage y, and the slide jacket has ports b¹ and c¹ for
the admission of gas and air; i is a burner for admitting the kindling flame to the
passage y which communicates also with an air port h¹. The passage a into the
cylinder in one position of the slide admits the mixture of air and gas supplied to
the cavity p, and during the rapid movement of the slide admits the kindling flame
which ignites the mixture in the cylinder; a smaller passage Q is placed a little
below the passage W, so that when the latter is stopped by the loose piston head d
the products of combustion still enclosed between the two pistons can only escape
very slowly, owing to the screw P thus acting as an air buffer and preventing

page_text: concussion of the two pistons. The passage W governed by the valve N permits
the products of combustion to issue from the cylinder, the valve N closing to
prevent ingress to the cylinder. In connection with the gas valve is a regulating
pump which is worked by the cam O. The piston or sucker u draws in and expels
at each revolution a small amount of liquid; if the revolutions follow one after
the other in too rapid succession all the liquid cannot be expelled; this causes the
lever j to lift and hold stationary the bar H, thus preventing a new charge of gas
being given until the speed has diminished.
The apparatus for clamping the rod of this piston and preventing it from
descending till the grip is relieved consists of four levers E, E, E, E, pressed down
by springs. The ends of the four levers E, E, E, E, are rounded, and enter notches
in a pair of clamps, which consist of a bush made in halves enclosing the piston
rod. The levers E, E, E, E, are a little inclined upwards, so that as they tend to
come down to a horizontal position they press the sides of the clamp firmly
against the piston rod and grip it, thereby preventing it from descending until the
excentric O¹, which is connected to the lever m, is brought round to such a point in
its revolution as to raise the inner end of the lever m, pushing upwards the clamp l,
and so relieving the piston rod and allowing the piston D to descend.
Having thus fully described the said Invention, as communicated to me, and the
manner of performing the same, I wish it understood that I claim, the gas engine
with parts constructed and combined, as shewn in the accompanying Drawing, and
in which the pressure produced by the ignition of an explosive gaseous mixture in
a cylinder is applied to propel two pistons in opposite directions, the one piston
being connected to a crank on a fly wheel shaft and the other being, after its
propulsion, held for a time by a clamp, for the purpose of utilizing as motive power
the reduction of pressure within the cylinder after explosion, and in which the
clamping and releasing of the piston rod is effected by the combined apparatus
consisting of spring levers set in an inclined position, so as to press the parts of a
divided bush against the rod and of a lever worked by an eccentric, so as to raise
the divided bush, relieving the rod of its pressure, and which is provided with the
regulating apparatus as herein described.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this Thirtieth day of September, in the year of our Lord One thousand
eight hundred and seventy-six.