IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1883

page_text: LETTERS PATENT to Edgar Coniston Mills of Barnes Green near Manchester
in the County of Lancaster Engineer for an Invention of "IMPROVEMENTS IN
GAS MOTOR ENGINES"
PROVISIONAL SPECIFICATION left by the said Edgar Coniston Mills at the
Office of the Commissioners of Patents on the 12th December 1883.
EDGAR CONISTON MILLS of Barnes Green, near Manchester in the County of
Lancaster, Engineer, "IMPROVEMENTS IN GAS MOTOR ENGINES"
My Invention relates principally to a former invention for which Letters Patent
number 5052 of the year 1879 have been granted to me in conjunction with a
certain Henry Haley but parts of my Invention are applicable to gas engines not
constructed in accordance with our first Invention.
Instead of a slide valve I use a seated valve to control the admission of the
charge the said valve opening inwards so that the force of the explosion tends to
close it. This valve is acted upon by a lever upon which a cam acts to keep the
valve closed excepting at the time when the cylinder is to be charged when
a depression in the cam permits the valve to open. The valve may be opened by
the pressure in the reservoir or the opening may be aided by a spring. I also
provide a locking arrangement connected with the governor so that at the required
times the opening of the valve and as a consequence the explosion of a charge
may be prevented. To stop the supply from the pump to the reservoir I employ
a release valve on which are seated a number of small valves which act as the
outlet valves from the pump and open against cushions. These valves being small
and light are quick and silent in action. To open the release valve at the required
times I employ a crank acting upon a lever which acts upon the valve spindle.
The crank is fixed or formed on a shaft which is caused by the engine to make a
partial rotation in obedience to the governor and thereby causes the release valve
to be opened whereby a free communication between the pump and the reservoir
is established. When in its normal position the crank resists the opening of the
D

page_text: release valve. To regulate the action of the lever I, arrange for the fulcrum to be
adjustable in position and to be locked or fixed by means of a screw or of a suitable
appliance.
To ignite the charge I employ a thimble preferably made of platinum which
projects into a small chamber or ignition box which communicates through a valve
with the explosion chamber in the cylinder or with a passage leading thereto.
Without the ignition box and projecting into the said thimble is a nozzle or burner
which is fed with compressed mixed gases either from the main reservoir or from
a small reservoir supplied directly from the pump or by means of a special pump.
To secure that the heat shall be maintained I find it necessary to obtain a diffusion
of the issuing gases. For this purpose I provide the nozzle with a cap consisting
of a layer or of layers of platinum gauzo or I use spongy platinum, porous earthen-
ware, asbestos, a finely perforated cap or other means. The nozzle is preferably
made of a good heat conductor such as copper or it may be of porcelain, steatite, or
platinum, or of a combination of one or more of these materials. The tip of the
thimble becomes heated and by preference the tip is situated opposite and near to
the inlet opening.
To actuate the valve which controls the admission of the explosive mixture to
the ignition box I employ a cam which may be fixed on the same shaft as the main
admission cam and acts upon a lever in a similar manner.
The shaft of the said
lever passes through a stuffing-box into the explosion chamber or passage and
carries a lever or finger to which the said valve is fixed or with which it is
connected.
To take the place of a large storage chamber for the charging mixture I use a
chamber having a self-varying capacity. On the way from the pump to the
cylinder the gases have access to a chamber having on one side a flexible diaphragm
which yields to admit the charge from the pump. The back of this diaphragm is
exposed to air or gases of a pressure corresponding to that required in the explosion
chamber when charged. The movements of the diaphragm are by preference
limited by the walls of the chamber. A charge is received by the pump and
delivered into the explosion chamber without great variations of pressure.
A
piston might take the place of the diaphragm. The air-pressure at the back of the
diaphragm may be maintained by any suitable means or by the following described
apparatus. A small diaphragm is exposed on one side to the varying pressures in
the pump cylinder and a space on the other side communicates with small inlet
and delivery valves the air from the latter passing into a chamber at the back of
the aforesaid diaphragm. By these means a pressure is maintained at the back
of the diaphragm and this pressure can never exceed the maximum pump pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edgar Coniston Mills in the Patent Office on the 12th June 1884.
EDGAR CONISTON MILLS of Barnes Green, near Manchester in the County of
Lancaster, Engineer "IMPROVEMENTS IN GAS MOTOR ENGINES
"
My Invention relates principally to a former invention for which Letters Patent
number 5052 of the year 1879 have been granted to me in conjunction with a
certain Henry Haley but parts of my invention are applicable to gas engines not
constructed in accordance with the said former invention.
Instead of a slide valve I use a seated valve to control the admission of the
charge the said valve opening inwards so that the force of the explosion tends to
close it. This valve is acted upon by a lever upon which a cam acts to keep the
valve closed excepting at the times when the cylinder is to be charged when a
depression in the cam permits the valve to open. I provide a locking arrangement
connected with the governor so that at the required times the opening of the valve
and as a consequence the explosion of a charge may be prevented. To stop the
supply from the pump to the reservoir I employ a release valve on which are
seated a number of small valves which act as the outlet valves from the pump and
open against cushions.
To ignite the charge I employ a thimble preferably made of platinum which
projects into a small chamber or ignition box which communicates through a
valve with the explosion chamber in the cylinder or with a passage leading thereto.
Without the ignition box and projecting into the said thimble is a nozzle or
burner which is fed with compressed mixed gases and is formed and provided as
will be hereinafter described. To actuate the valve which controls the admission
of the explosive mixture to the ignition box, I employ a cam which may be fixed
on the same shaft as the main admission cam and acts upon a lever in a similar
manner. The shaft of the said lever passes through a stuffing box into the
explosion chamber or passage and carries a lever or finger to which the said valve
is fixed or with which it is connected.
To take the place of a large storage chamber for the charging mixture I use a
chamber having a self-varying capacity. On the way from the pump to the
cylinder the gases have access to a chamber having on one side a flexible diaphragm
which yields to admit the charge from the pump. The back of the diaphragm is
exposed to air or gases of a pressure corresponding to that required in the explosion
chamber when charged. The air pressure at the back of the diaphragm may be
maintained by any suitable means or by the hereinafter described apparatus.
In order that my invention may be fully understood I have attached hereto two
sheets of drawings to which I will refer when describing my invention. In sheet 1
of the said drawings Figs 1 and 2 illustrate the arrangement for admitting the
charge to the cylinder. In the said Figs a is a valve chamber which communicates
with the cylinder and b is a valve which is seated within the said chamber. The
said valve is fixed to a spindle c which passes through a gland d and is provided
with a slotted head c¹ and is acted upon by a spring f which imparts to the lever
a tendency to open the valve. The compressed gases are conveyed into the
chamber g and by their pressure also tend to open the valve. Connected with the
lever e and rocking on the same stud is a second lever h which is acted upon by a
•

page_text: A
in
revolving wheel or cam i which is fixed upon a shaft ; and acts through the last
named lever upon the lever c to keep the valve closed a set screw c² furnishing
means for adjustment so that the valve is closed sufficiently tight. A depression
in the cam permits the valve to open at the required time in each revolution for
the admission of the charge to the cylinder. Upon a fulcrum pin k is mounted a
locking lever which is formed with a step at and is connected by means of a
rod which is jointed to its lower end with the governor. So long as the lever e is
locked by the locking lever the valve cannot open. The connection with the
governor is such as that when the speed becomes reduced the lever e is unlocked
and the valve is permitted to open at the proper time.
The sectional views
Figs 3 and 4 in sheet 2 illustrate the construction of the aforesaid release valve.
In Fig 3 m is the passage communicating with the pump n is the passage leading
to the reservoir and cylinder o is the air inlet and p is the gas inlet. Between the
passages m and 'n is seated a circular valve 9 and upon this valve are seated four
smaller valves 7, r, which act as discharge valves for the pump. These valves
open against cushions of suitably elastic material and are closed by means of spiral
springs. The main valve is secured to a spindle s which passes through a slot in
a levert which is mounted upon a fulcrum at u. The slotted part of this lever
is rounded on each side and this part is situated between adjustable lock-nuts upon
the spindle so that by acting upon the lever the valve can be opened or closed.
rocking shaft v passes through a gland into a chamber in which the lever t is
mounted and on the inner end of this shaft is fixed a lever w which carries a stud
that works in a slot in the free end of the lever t. On the outer end of the shaft v
is fixed a second lever a to which is jointed a rod which is connected with the
governor and which may be the aforesaid. rod that acts upon the locking lever
sheet 1. At the times when the engine is working at above its normal speed or
when a fresh charge is not required the said rod moves the said lever into its
locking position and at the same time turns the shaft so that the inner lever w
moves the slotted end of the lever in the direction which would be downward in
the drawing whereby the release valve is opened and the compressing action of
the pump is arrested. It will be seen that when the lever tis in its normal
position indicated in the drawing-it is in a position favourable to the keeping
of the release valve closed. The position of the fulcrum u can be adjusted so that
the lever will hold the valve to its seat with a suitable degree of force. The said
fulcrum is fixed in a sliding block or carriage which is connected with the end of
a screw Z. By turning: this screw the fulcrum can be shifted in the required
direction the screw being then secured by means of the lock nut shown. The
number of the smaller valves mounted upon the release valve may be varied.
These valves being small and light are quick and silent in action. Figs 5, 6 and 7
illustrate the arrangement for igniting the charge. In Fig: 7, a¹ is the ignition
box or chamber to which the explosive mixture is admitted at the required times
through a pipe b₁ which is closed at other times by means of a valve d¹ seen in
Fig 6. The said valve is carried by a lever e¹ which is fixed upon a rocking
shaft which passes through a gland to the exterior of the casing. On the outer
end of this shaft is fixed a lever or finger g¹ which is acted upon by a spring which
tends to move the lever in the direction to open the valve. This movement of the
lever is prevented by a revolving cam ' excepting at the time in each revolution when
a depression in the cam is brought opposite to the lever end when the valve is per-
mitted to open. The said cam is fixed upon a shaft ; which may be the shaft indicated
in Figs 1 and 2. The gases passing through the valve opening have access to the
exterior of a platinum thimble which projects into the box a¹ and is carried by a part i¹
which is preferably made of porcelain or other refractory substance or composition.
Into the interior of the thimble projects a copper nozzle which is preferably lined
and coated with platinum in order to check oxidation and is fed with compressed
mixed gases or gas and air either from the main reservoir or from a small special 5

page_text: reservoir supplied directly by the pump or by means of a special pump. To ensure
the maintainence of the heat I find it necessary to obtain a diffusion of the issuing
gases. For this purpose I provide the tip of the nozzle with a cap consisting of a
layer or of layers of platinum gauze. The heat generated might sometimes be
sufficiently intense to melt this cap but to prevent this I make the nozzle k¹ of
copper and of ample substance so that it conducts a portion of the heat away from
the cap.
I may employ other good heat conducting material but I now consider
copper to be the most suitable and I may use spongy platinum porous earthenware,.
asbestos or a perforated cap or other means for ensuring the diffusion of the gases.
The cap is held in place by means of a shield of platinum and the products of
combustion escape into a chimney m¹. By means of this arrangement I am enabled
to dispense with a master light. I do not claim the use of the thimble apart from
the. nozzle. Fig: 8 is a sectional view of the arrangement whereby I dispense
with a large storage chamber. A flexible diaphragm m¹ is secured between two
parts n and o¹ which are hollowed so that chambers are formed on each side of
the diaphragm. The chamber on one side communicates by means of passages p¹
and p2 with the pump and with the working cylinder and the chamber 71 on the
other side communicates with a reservoir of air compressed to the pressure required
for the charge in the explosion chamber. It will be seen that the diaphragın
yields to make room for the gases delivered by the pump and by reason of the
pressure of air within the chamber forces the charge into the working cylinder.
Figs 9 and 10 illustrate the construction of a small apparatus which may be used
to keep up a pressure of air in the reservoir which communicates with the
chamber A diaphragm s' is exposed on one side to pressure in the main pump
and a chamber t on the other side communicates with spring inlet and discharge
valves h¹. A passage v¹ leads from the delivery valve to the said reservoir. As
the pressure in the pump cylinder varies the diaphragm is caused to act as a pump
whereby at the times when the pressure within the said reservoir becomes less than
the maximum pressure in the pump cylinder air is forced into the said reservoir to
restore the pressure which it will be seen can never exceed the maximum pressure
in the pump cylinder.
Having now fully set forth and indicated the nature of my said invention and
the manner in which I carry the same into practical effect I would have it to be
understood that I claim:-
First. The admission valve opened by the gas pressure with or without the aid
of a spring in combination with the recessed wheel or cam which keeps the valve
closed excepting at the times when a charge is to be admitted to the cylinder
substantially as set forth and indicated.
Secondly, The employment of a locking lever connected with the governor to
prevent the said admission valve from opening at the times when the admission of
a charge is not required substantially as set forth and indicated.
Thirdly. The release valve having two or more delivery valves seated upon it
substantially as and for the purpose set forth and indicated.
Fourthly. The combination of levers and parts with their adjustments connected
with the governor substantially as and for the purpose set forth and indicated with
reference to Figs 3 and 4 of the drawings.
Fifthly. The combination of a platinum firing thimble with a nozzle and
diffuser for mixed gases constructed and acting substantially as and for the purpose
set forth and indicated.
Sixthly. The arrangements for opening and closing the valve which admits
gases to the ignition box substantially as set forth and indicated.
Seventhly. The employment of a diaphragm substantially as set forth and
indicated with reference to Fig: 8 of the drawings.
And lastly. The method of keeping a reservoir supplied with compressed air

page_text: substantially as set forth and indicated with reference to Figs 9 and 10 of the
drawings.
In witness whereof I the said Edgar Coniston Mills have hereunto set my hand
and seal this eleventh day of June in the year of our Lord one thousand eight
hundred and eighty-four
Signed, sealed, and delivered
in the presence of
"
EDWARD K. DUTTON
}
41 John Dalton St Manchester
(Agent for the Patentee)
EDGAR CONISTON MILLS. (L.S.)