Improvements in Internal Combustion Engines.
Year: 1893

page_text: Date of Application, 13th May, 1893
Complete Specification Left, 13th Feb., 1894-Accepted, 17th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Internal Combustion Engines.
I, JAMES ROOTS Engineer Holborn Place 261 High Holborn London do
hereby declare the nature of this invention to be as follows:-
The piston altho' preferably in one casting is made of two diameters, the smaller
being connected to the connecting rod and reciprocates in the guide or smaller
diameter of the cylinder which is unjacketed and is bolted on to the front of
the cylinder forming its front cover. The air is drawn into the annular space
on the cylinder front surrounding the smaller diameter of piston through a port
in the cylinder wall, a portion of this air is displaced or ejected through the same
port on the return stroke, the rest is compressed and a portion of this is forced
through a port to the other end of the cylinder and opposite side of piston through
the admission valve, without any fuel either gas or oil vapor mixed with it, then
the larger part of the air so compressed is mixed with gas or oil vapor and flows
by a different channel to and through the same valve or port to the combustion
side of the piston and working end of the cylinder or a contracted extension of it
where it is ignited by a hot tube after compression or by other known method.
The piston performs the working stroke, and the exhaust valve is opened by a side
rod and excentric just before the working stroke end when the pressure has fallen
to nearly atmosphere the exhaust products are then displaced during the return or
instroke of the piston for about half the stroke the exhaust valve then closes
and the remaining contents of the cylinder and combustion chamber are compressed
and fired.
This obtains an impulse every revolution and a much greater expansion without
the wasteful back pressure on the piston through so large a portion of the stroke
and yet the likelihood of the charge firing on entering is reduced to a minimum, as
air only enters first.
The feed of oil is effected and measured by a spindle rotated by the engine.
Upon the spindle a deep screw thread is cut for a portion of its length. The
spindle rotates in a casting drilled to fit it containing an oil channel in connection
with the oil tank, also (with the solid bearing between), an air channel, the screw
rotating conveys oil from the the oil channel to the air channel where it is swept
off by the heated air as described in my former Specification 19275”. The size of
the screw groove and the number of rotations determine the feed of oil. The
governor is connected to the spindle so that at excess speeds the screw thread is
pulled out of the oil leaving in the oil a plain or uncut part of the spindle and the
feed ceases.
For varying speeds this arrangement may be modified by making the
spindle slightly conical and cutting pockets in it one for each cylinder, if more than
one, the oil space or channel is then placed at an opposite point to the air channel,
so that as the spindle rotates each pocket is brought opposite the air channel which
is so directed that the heated air sweeps directly into the oil pocket and clears out
its contents. In this case the same governor operates by preventing rotation of
the spindle. A gland may be fitted to prevent leakage.
The air heater and vaporiser shown in my previous Specification may be simply
inverted that is the vaporiser is placed at the bottom and its cover may have a
rib on it nearly annular to give greater heating surface.
If gas be used it is mixed with the air in a chamber or channel placed near the
gas valve and the same excentric rod used for operating the exhaust valve is also
used for opening the gas valve.

page_text: The lever which opens the valve being controlled by the governor by means of
a sleeve which pulls the lever out of line with the gas valve spindle and the gas
valve remains closed.
In using petroleum oil fuel, the burner is constructed of a small coil of piping
enclosed within a casing preferably nonconductive.
One end of the pipe connected to the burner coil is fitted to a blower or
bellows of any known type and the other end of the coil is bent round so as to
direct the issuing stream of oil and air straight through the coil, in the channel
of which the oil is mixed with the air and both are heated together on their
passage through the coil burner and produce a blue or atmospheric flame.
The oil is fed to the burner from the main supply by any known method.
Dated May 12th 1893.
JAMES ROOTS.
COMPLETE SPECIFICATION.
Improvements in Internal Combustion Engines.
JAMES ROOTS Engineer Holborn Place 261 High Holborn London do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described aud ascertained in and by the following
statement:-
The piston altho preferably in one casting is made of two diameters, the smaller
being connected to the connecting rod and reciprocates in the guide or smaller
diameter of the cylinder, which is unjacketed, and is bolted on to the front of the
cylinder forming its front cover. The air is drawn into the annular space on the
cylinder front surrounding the smaller diameter of piston, through a port in
the cylinder wall, a portion of this air is displaced or ejected through the same port
on the return stroke, the rest is compressed and a portion of this is forced through
a port to the other side of the cylinder through the admission valve, without any
fuel either gas or oil vapor mixed with it, then the larger part of the air so compressed
is mixed with gas or oil vapor, and flows through the same valve or port to the
combustion side of the piston, and working end of the cylinder, where it is ignited
by a hot tube after compression. The piston performs the working stroke, and the
exhaust valve is opened just before the working stroke end, when the pressure has
fallen to nearly atmosphere, the exhaust products are then displaced during the
return or in stroke of the piston for about half the stroke, the exhaust valve then
closes, and the remaining contents of the cylinder and combustion chamber are
compressed and fired.
This obtains an impulse every revolution, and a much greater expansion, without
the wasteful back pressure on the piston through so large a portion of the stroke,
and yet the likelihood of the charge firing on entering is reduced to a minimum as
air only enters first.
The feed of oil is effected and measured by a spindle rotated or partially rotated
by the engine. Upon the spindle a deep thread is cut for a portion of its length.
The spindle rotates in a casting drilled to fit it, containing an oil channel in
connection with the oil tank, also (with solid bearings between) an air channel, the
screw rotating conveys oil from the oil channel to the air channel, where it is swept
off by the heated air as described in my former Specifications. The size of the
screw groove and the number of rotations determine the feed of oil. The governor
is connected to the spindle, so that at excess speeds the screw thread is pulled out
of the oil, or ceases to rotate, leaving in the oil a plain or uncut part of the spindle
and the feed ceases. This arrangement may be modified by making the spindle
slightly conical, and cutting pockets in it, one for each cylinder, if more than one,
the oil space or channel is then placed at an opposite point to the air channel, so
that the spindle rotating, each pocket is brought opposite the air channel, which is

page_text: so directed, that the heated air sweeps directly into the oil pocket and clears out
its contents. In this case the same arrangement of governor operates by preventing
rotation of the spindle. A gland may be fitted to prevent leakage.
The air heater and vaporiser shown in my previous Specification may be simply
inverted, that is, the vaporiser is placed at the bottom and the cover may have a
rib cast on it nearly annular to give greater heating surface.
If gas be used it is mixed with the air in a chamber or channel placed near the
gas valve, and the same excentric rod used for operating the exhaust valve is also
used for operating the gas pump, by means of which the gas valve is opened.
In using petroleum oil fuel, the burner is constructed of a small coil of piping
enclosed within a casing which may be lined with a non-conductive.
One end of the pipe connected to the burner coil is fitted to the oil feeder and to
a blower or bellows of any known type, and the other end of the coil is bent round
so as to direct the issuing stream of oil and air straight through the coil, in which
the oil is mixed with the air, and both are heated together on their passage through
the coil burner, and produce a blue or atmospheric flame.
The same letters refer to the same or similar parts in each figure.
Fig. 1 is a horizontal or plan section through the cylinder. Fig. 2 an end
elevation.
Fig. 3 is a view of the side of the cylinder showing the exhaust valve, gas pump,
and lever.
Fig. 4 a side elevation showing this method of working as applied to an oil
engine.
Fig. 4 shows a section of the vaporiser arranged with oil feeder.
Fig. 4B a section of the oil feeder.
Fig. 5 a modification of the oil feed arrangement.
Fig. 5, another view of the same.
Fig. 5 shows one method of application of this oil feed to the vaporiser.
Fig. 6 is a section of the burner.
In Figs. 1, 2, & 3, A is the cylinder, B the cover, C the larger diameter of piston,
D the smaller diameter or crosshead which carries the connecting rod end and
which works in the guide D¹, E is the air valve, E¹ the pipe conveying the air,
Fan air port, G the admission valve for gas and air, G¹ the admission port, H the
exhaust valve, H' its port, I the gas pump, J the gas valve, K the gas delivery
pipe, L the ignition port, M the ignition tube casing, N the excentric on the crank
shaft, N' the excentric rod, O the gas pump lever, P the gas piston rod (Fig. 3),
P1, P2, springs on the gas piston rod.
In Figs. 4, 4 and 5, Z is the air and oil heating casing, and Y the oil feeder.
In Fig. 4 the spindle of the valve E for air inlet is placed horizontally, and the air
pipe El as in Fig. 1 is divided into two pipes, the one E conveys air to the air and
oil heating casing Z, and the other E 3 directly to the admission valve box G. In
Figs. 44 and 4B W is the oil cock, WI is the oil space, X the screw thread which
conveys oil from the oil space W1 to the air space Y', whence it is conveyed by
the pipe W 2 to the air channel V 1 which connects the vaporiser channel V with
the air heating channels V 2. The oil feed casing Y may be cast in one with the
air channel V1 as shown in the modified arrangement in Figs. 5 and 5^. Also if
a very heavy oil be used the pipe W 2 may feed its oil into the top channel of V 2
in order to pass the oil and air together through a greater length of channel.
The screw thread X' on the spindle X is rotated by means of the toothed
wheel X2 on its end, which gears into the toothed rack X3, Figs. 4 and 4* which
is operated by the admission valve G by means of the lever X 4 connected to its
spindle Fig. 4.
In Figs. 5, 54, and 5B the spindle X is shorter, and tapered like a plug and has
cut in it a pocket X', which being given a to-and-fro movement or partial rotation
by means of the arm X 2, the pocket is filled with oil and presented to the heated
moving air which sweeps out the pocket.
The burner Fig. 6 is formed of a coil of piping U surrounded by a tube casing T

page_text: which may be lined with asbestos. To start the engine the burner is heated and
supplied with oil by means of an ordinary syphon wick from the oil tank R, through
the two way cock T1 and with air by means of an ordinary hand pump or fan.
When the ignition tube and vaporiser are sufficiently heated, the flame from the
burner playing through the hole Z 2 in the casing Z, Fig. 4A, the two way cock
is turned, and the burner is supplied with air and oil by means of the pipe T2 on
the oil feeder Y, Fig. 4B, connected to the cock T 1. The air and oil are beated
and mixed by passing through the coil U so that they form a complete gas in a
similar manner, only on a smaller scale to that shown in my Patent 158828. The
mixture issuing from the end of the bend U 1 injects and mixes with further air
in the tube casing T.
In Figs. 5, 5, and 5 the feeder X is given a partial rotation or oscillation by
means of the lever X 4 and valve G, as before described.
Referring to Fig. 1, air is drawn into the space in the front of the cylinder A
by the backward movement of the piston C, through the valve E, until the port F
is opened by the piston uncovering it when the valve E closes, and for the rest of
the stroke about one half of it, air enters the cylinder by the port F, the piston
returns on its forward stroke, and ejects or displaces the air from the cylinder
until the piston again covers the port F, when the remainder of the air left in the
front or pump end of the cylinder is slightly compressed, and flows by the pipe E¹
through the admission valve G, by the port G 1, into the working end of the cylinder,
a small quantity having passed through, the gas pump I immediately begins to
deliver its charge by means of the excentric rod, and lever O, through the pipe K
to the valve box G, where it mixes with the entering air. Immediately after
the dead point the valve G closes, and the exhaust valve H which is open, is still
held open by the excentric until the piston has about reached the middle of the
stroke on its return, when the excentric permits the exhaust valve to close. The
new charge and products then left in the cylinder are compressed and fired by
the hot tube through the port L just after the dead point, when the piston is
nearest the cover and the charge expands to about, or rather more than double
the volume, and nearly to atmosphere. The exhaust valve is then opened by the
excentric a little before the end of the working stroke, and the air then enters
through the valve G, and the series of operations commences again.
It will be observed that the back pressure on the piston during half the working
stroke is obviated, and the slight compression required to charge the working end
of the cylinder is done during about half the stroke. In delivering also about half
the usual charge to the working side of the cylinder, and in retaining the exhaust
valve open during half the instroke to exhaust, double expansion is obtained.
It will be obvious that instead of a guide and smaller diameter of piston, that
an ordinary piston rod passing through a gland may be used, the construction
shown is only with a view to reducing the total length of the engine.
It will also be obvious that in place of having a port F in the cylinder wall through
which to draw in and displace air from the cylinder, the valve E may be kept
open by another excentric rod as shown in Fig. 4, for about half the stroke to
serve the same purpose.
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 an internal combustion engine, in which air is drawn into one end of
the cylinder to supply part of the combustion charge fired in the other or
working end, preventing the back pressure on the piston through a part of the
working stroke by means of an open port or valve, through which a portion of
the air or charge, that would be otherwise compressed, is displaced.
2. In an internal combustion engine of the kind described, the cycle of opera-
tions comprising the drawing in of air only in the pump end of the working
cylinder, the ejecting a portion of this air from the cylinder, the delivery of

page_text: the remainder to the working end of the cylinder, mixed with the necessary
fuel on its way, the displacement of products through the exhaust valve for the
same length of stroke during which air was displaced, and the compression and
ignition of the remaining charge.
3. In an internal combustion engine of the kind described, the combination of
a piston in a cylinder, with the necessary mechanism for permitting the eject-
ment of a part of the air from the pump end of the cylinder, and for permitting
the ejectment of a like volume of products from the working end of the same,
substantially as described and shown.
4. The combination of the piston, cylinder with port F, valves E, G, and H,
with gas pump and operating lever, as described and shown.
5. The combination of the parts of an oil engine as described and shown in
Figs. 4, and 5B.
6. The oil feeder as described and shown in Figs. 4^, and 4; and its means
of operation as described and shown in Fig. 4.
7. The oil feeder, and its means of operation as described and shown in
Figs. 5, 5, and 5º, in which an oscillating pocket delivers the oil.
8. The construction and arrangement of burner as described for starting, and
subsequent running, and as shown in Fig. 6.
February 12th 1894.
JAMES ROOTS.