Year: 1889

page_text: We, ANDREW SCLANDERS NELSON of 28 Snowdon Place, Stirling, Engineer, and
JOHN GLASSFORD MCMILLAN of Kilwinning, Ayrshire, 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 improvements in gas motor engines, the said improvements
referring mainly to the governor and valve arrangements whereby suitable apportion-
ment of the gas and air forming the combustible charge or mixture supplied to the
cylinder is effected in such wise as to secure the maximum of efficiency and economy.
In the accompanying drawings which illustrate the invention figure 1 is a sectional
elevation, figure 2 an end elevation figure 3 a plan and figure 4 a cross sectional
elevation of a gas motor engine embodying our improvements. Figure 5 is a
sectional view of the governor and valve arrangements for controlling the admission
and firing of the charge, figure 6 is an end view, figure 7 an elevation showing the
means employed for firing the chargo and figure 8 a plan of the same.
Figures 9, 10,
11 and 12 are horizontal sections of the valve casing and admission valve or key
showing the latter at various positions assumed by it during its rotation, and figures
13 and 14 are detached views of the said valve.
A is the cylinder which is water jacketed as usual and is supported on a bed or
base B serving also to carry the bearings for the crank shaft C. Dis the piston and E
the connecting rod through which its movement is communicated to the crank disc F.
On the crank shaft is a worm g gearing with and driving a worm wheel G on a shaft H
whose opposite end is fitted with a bevel pinion I gearing with a like pinion I keyed
on a conical valve J which rotates in a casing K bolted to the side of the cylinder A
the transmitting gear being so arranged that the valve J completes one revolution for
every two revolutions of the crank shaft C. The valve or key J is provided with two
ports, communicating with each other through a slot formed in the key and
serving for the passage of the combustible charge from an admission port & in the gas
and air valve chest or casing K to a port opening to the cylinder A. An ignition
port is also formed in the valve which at the proper time in the rotation of the valve

page_text: places the charge in the cylinder in communication through the port with an
ignition tube L whoso outer end is closed and which is maintained at a red heat for
firing the charge by means of a Bunsen burner flame playing upon it within a
funnel I¹.
The supply of air is drawn in through a passage M in the valve casing which may
or may not be provided with a self closing lift valve M² opened by suction of the
piston on its outstroke, and the supply of gas is taken through a passage N and a
series of perforations n around a liner n in the passage M which constitutes the seat
for the lift valve when such is provided, the gas and air hoth entering a mixing
chamber in the valve chest K on their passage to the admission port . The
passage N for the gas supply kept normally closed by means of a valve O which is
attached to and operated by a lever P centred at p on a bracket and having on its
free end a disc pl which is in the path of movement of a cam piece q formed or fitted
on a centrifugal ball governor Q centred on the spindle J of the rotating valve J.
In the operation of the engine the rotation of the valve J at a greater or less rate
due to variations of speed of the engine causes the ball or weight Q to be thrown more
or less outwards from the spindle J¹ of the valve J and the cam piece q accordingly
more or less inwards whereby said cam q in its rotation is brought into contact with or
caused to miss the disc pl. At the normal speed the cam piece q comes in contact
with the disc p¹ and raises the lever P and with it the gas valve O at each
revolution of the valve J that is, once for every second revolution of the crank shaft.
The cam q is set to act on the-disc p at the commencement of the outstroke of the
piston in the cylinder and to clear the said disc at about half stroke of the piston but
it may be made adjustable or interchangeable in order to clear the disc and permit the
gas valve to close at any other part of the stroke of the piston. Whilst the gas valve O
is kept open by the action of the governor the piston on its outstroke draws in gas and
air through the passages M N and the ports in the valve J, and on the closing of the
gas valve it continues to draw in air alone through the passage M and said ports until
the end of the outstroke by which time the valve J has turned sufficiently to close the
.communication through the posts in it with the cylinder. On the in-stroke of the
piston the combustible charge is compressed the valve poris being closed and by
the commencement of the next outstroke the valve J has turned so that the ignition
port places the interior of the cylinder in communication witn the ignition tube L
whereupon the combustible charge is fired, and the piston driven outwards. On the
return instroke the products of combustion are driven out through an exhaust passage
R and valve S which is normally closed by a spring S' but is opened at the proper
time by means of a lever S acted on by a wyper S³ on the rotating shaft H. Figure 9
shows the position of the valve J at the beginning of the suction stroke, Figure 10, at
the beginning of the compression stroke, Figure 11, at the ignition point or beginning
of the expansion stroke and Figure 12 at the beginning of the exhaust stroke.
l
During compression and when the explosion takes place a diaphragm T closing an
orifice in the exhaust passage R is subjected to upward pressure and acting through
the rod T¹ and lever T2 which is provided with adjusting screws t forces down the
valve J in its seat and prevents the escape of gas or residual products through the valve
seat. By means of such provision the valve J may be fitted loosely to rotate in its
seat with a minimum of friction the pressure on the diaphragm in the exhaust chamber.
serving to tighten the valve at the moment of explosion whilst the valve is again
relieved when the pressure falls.
To provide for obtaining access to the interior of the gas and air passages M.Na
screw plug or cap U is fitted in the end of the passage M and in order to provide for
cleaning out the horizontal portion L' of the ignition tube L a screw.plug V is fitted
in the casing in the line of said tube.
.
In lieu of the heated tube L a naked flame or jet may be used in conjunction with
the ignition port arrangements described for firing the charge in the cylinder.
Taps or valves are fitted in the gas and air supply pipes to determine the relative
proportions of the mixture to be supplied to the cylinder in. the early part of the
suction stroke of the piston.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
:―
1. The combination of parts constituting the improved gas motor engine horein-
before described with reference to the drawings annexed.
2. The combination of parts composing the gas and air admission valve arrange-
ments hereinbefore described with reference to figures 5 to 14 of the annexed
drawings.
3. In a gas motor engine the arrangement of the governor and gas valve operating
to cut off the supply of gas at any desired part of the stroke of the piston substantially
as described with reference to the accompanying drawings.
Dated this Twenty-eighth day of March 1889
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.