Improvements in and connected with Gas and Oil Engines.
Year: 1899

page_text: Date of Application, 14th Oct., 1899
Complete Specification Left, 16th July, 1900--Accepted, 25th Aug., 1900
PROVISIONAL SPECIFICATION.
Improvements in and connected with Gas and Oil Engines.
I, ALFRED GEORGE MELHUISH, of 20, Hinckley Road, Peckham, in the County
of London, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to the particular method of distributing or regulating
the influx of the combustible mixture to the cylinder of a gas or oil engine
and also of the exhaust gases therefrom the object being to so construct and
arrange the operative parts, that ordinary mushroom butterfly or other valves,
that fall or are pushed upon their seatings and their consequent rattle and noise
and liability by the adhesion of foreign matter upon their faces to get out of
order are dispensed with.
Moreover to so place these operative parts beforementioned that no orifice
such as inlet or outlet occurs in the combustion chamber or working part of
the cylinder except at that part near the end of the pistons stroke where
there is less liability of leakage during expansion of the exploded charge.
My invention is particularly applicable to that class of engine described by
me in Patent No. 9038 of '95, but I do not limit, its application to this type
of engine as with minor and unimportant modifications such as hereinafter
set out for example, it is applicable to other forms of engines.
Describing the manner of carrying out the invention in connection with
that type of engine shewn in Specification No. 9038 of '95, I arrange that the
working cylinder has no valve, and the port that communicates with the atmos-
phere, and is uncovered by the working piston at or near its extreme outstroke
is covered by a slide or D valve operated preferably by an eccentric from the
crank shaft, this D valve slides upon a face in which are three ports one say
above and the other below the port communicating with the cylinder, one of
these ports communicating with an air supply and the other with an exhaust
pipe. Now the slide or D valve when in action. alternately puts the air
supply port and the exhaust port in communication with the middle port
leading into the cylinder, the position of the eccentric on the crank shaft being
so arranged that the following operations take place in the sequence required.
It should be said here that the top of the working piston is fitted or formed
with a deflector for directing the incoming gases to the combustion end of the
cylinder. At the point nearly coinciding with the extreme outstroke of the
working piston, the middle port is passed by said piston and the slide or D
valve puts said middle port in communication with the exhaust port for the
relief of pressure in the working cylinder the relation of the eccentric with
the crank being such that the D valve is moved to cut off the exhaust and
open communcation with the air inlet at the same time that the working piston
opens communication with the larger cylinder for suction to take place, which
causes an inrush of air & gas to enter the working cylinder & be deflected
towards the combustion chamber for compression by the return stroke, when

page_text: communication is again opened to the exhaust port by the slide or D valve for
the discharge of the contents from the larger diameter cylinder. The slide has
a hole or small port which coincides with the gas entry at the same time as
the air admission port allowing same to enter together. I may also use the
same slide or valve to time the ignition.
When used in connection with engines having a single trunk piston I arrange
the inlet port half-way along the cylinder or thereabouts.
Dated this 14th day of October 1899.
Improvements in and connected with Gas and Oil Engines.
I, ALFRED GEORGE MELHUISH, of 20, Hinckley Road, Peckham, 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:---
This invention relates to the particular method of distributing or regulating
the influx of the combustible mixture to the cylinder of a gas or oil engine
and also of the exhaust gases therefrom; the object being to so construct and
arrange the operative parts, that ordinary mushroom, butterfly or other valves,
that fall or are pushed upon their seatings and their consequent rattle and
noise, and liability by the adhesion of foreign matter upon their faces to get
out of order are dispensed with.
Moreover to so place these operative parts before mentioned that no orifice
such as inlet or outlet occurs in the combustion chamber or working part of
the cylinder, except at that part near the end of the pistons stroke where there
is less liability of leakage during expansion of the exploded charge.
My invention is particularly applicable to that class of engine described by
me in Patent No. 9038 of 1895, but I do not limit its application to this type
of engine as with minor and unimportant modifications such as hereinafter
set out for example, it is applicable to other forms of engines.
Describing the manner of carrying out the invention in connection with that
type of engine shewn in Specification No. 9038 of 1895, I arrange that the
working cylinder has no valve, and the port that communicates with the atmos-
phere and is uncovered by the working piston at or near its extreme out-
stroke is covered by a slide or D valve operated preferably by an eccentric
from the crank shaft, this D valve slides upon a face in which are three ports
one say above and the other below the port communicating with the cylinder,
one of these ports communicating with an air supply and the other with an
exhaust pipe. Now the slide or valve when in action alternately puts the
air supply port and the exhaust port in communication with the middle port
leading into the cylinder, the position of the eccentric on the crank shaft being
so arranged that the following operations take place in the sequence required.
It should be said here that the top of the working piston is fitted or formed
with a deflector for directing the incoming gases to the combustion end of the
cylinder.
At the point nearly coinciding with the extreme outstroke of the working
piston, the middle port, is passed by the said piston and the slide or D valve
puts said middle port in communication with the exhaust port for the relief of
pressure in the working cylinder the relation of the eccentric with the cranks
being such that the D valve is moved to cut off the exhaust and open com-

page_text: munication with the air inlet at the same time that the working piston opens
communication with the larger cylinder for suction to take place, which causes
an inrush of air and gas to enter the working cylinder and to be deflected
towards the combustion chamber, for compression by the return stroke, when
communication is again opened to the exhaust port by the slide or D valve
for the discharge of the contents from the larger diameter cylinder. The slide
has a hole or small port which coincides with the gas entry at the same time
as the air admission port allowing same to enter together. I may also use the
same slide or valve to time the ignition.
When used in connection with engines having a single trunk piston I arrange
the inlet port half way along the cylinder or thereabouts.
To enable my invention to be thoroughly understood I have appended the
accompanying sheet of diagrammatical drawings in which Figure 1 is a sectional
plan of cylinder as constructed in my previous Patent No. 9038 of 1895 but
is without valves.
Figures 2 and 3 are views shewing the different positions of the slide valve.
A is the motor cylinder and B is the pump cylinder in which a vacuum or
partial vacuum is formed by the outstroke of piston D which is driven by
the impulse of explosion upon piston D communication being made between
the two cylinders by a port C at the complete outstroke of the piston D, D'.
Before the complete outstroke is made it is necessary that any pressure remain-
ing in the cylinder A should be relieved. This is accomplished by way of
the port E, through the port H of the slide valve I, which is operated by a
connecting rod J and eccentric K mounted on the crank shaft I, to which
motion is imparted by the rod I in the usual manner.
The eccentric K is pre-
ferably placed in the position shewn in Figures 1, 2 and 3, relatively to the
crank. In the diagram Fig. 1, any excess of pressure remaining in the cylin-
der A can pass out through the port E and port H to the exhaust F but upon
the continued movement of the crank I¹, and eccentric K the piston D will
uncover the port C and the slide L will have covered both ports G and H in
this position, therefore the remaining products in cylinder A are partially with-
drawn into cylinder B.
The continued movement of the eccentric will before the return stroke of
piston commences, place the slide L in the position shewn at Figure 2, where
it will be seen the exhaust is closed, but communication is open to the gas
and air port G, the gas and air now rushing in and are deflected to the end
of the cylinder A and in so doing push the remains of the previous explosion
(or nearly so) into the cylinder B, which will then be at atmospheric pressure.
The piston D and D now returns in the one case to compress the mixture in
the cylinder A in the ordinary way and in the other to discharge the products
from the cylinder B. During the first portion of the return stroke the piston D
covers the port E so that it is immaterial what movement the valve is making,
but by the time the piston D has passed the port E, as in Figure 3, the eccen-
tric will have moved the slide L to the position indicated in Figure 3, for
the exhaust to be pushed out through the ports E, H and F, the continued
movement of the eccentric fully opening the ports and closing same on the
backward travel. The connecting rod of the slide is preferably slotted so that
upon the forward movement of the piston and eccentric the slide L remains
stationary until such time as the front end of the piston D covers the port E,
by which time the connecting rod slot will have again made contact with the
pin of the slide to move it to the position shewn in Figure 1 for the relief of
pressure, the movements afterwards being again gone through as before. From
this it will be seen that any pressure upon the slide L is largely from the
outside thus tending to keep same properly upon its face. That the slide has
not to withstand any internal pressure it being simply selective in its action
determining the time of relief of pressure, and inlet of gas and air, its object
being to allow of the relief of pressure, inlet of gas and air and exhaust to

page_text: pass out of and into the cylinder by a single port E, without either gases
mixing with each other, at the same time dispensing with mushroom or other
drop valves which are noisy in action and liable to leakage.
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―
The combination with a two cycle gas or oil engine of the kind described
in my previous Patent No. 9038 of 1895, of a slide D ported valve working
against a three ported face in the motor cylinder in the manner and for the
purpose described and constructed substantially as shewn.
Dated this 16th July 1900.
R. CORE GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for Alfred George Melhuish.
R. CORE GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for Alfred George Melhuish.