Improvements in Gas Motor Engines.
Year: 1891

page_text: .Date of Application, 18th June, 1891
Complete Specification Left, 7th Nov., 1891-Accepted, 12th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Gas Motor Engines.
'We, AUGUSTIN FIDDES and FRANCIS AUGUSTIN FIDDES, Engineers, both of
Lewin's Mead in the City and County of Bristol do hereby declare the nature of
this invention to be as follows
Our invention relates to improvements in gas motor engines and has for its object
the filling of the space or chamber in the cylinder beyond the stroke of the working
piston with a combustible charge to increase the power of the engine; and also, to
make use of the unexpended energy which remains after the working piston has
completed its working or combustion stroke, to still further increase the power of
the engine as hereafter described.
In gas motor engines we have found it advantageous to fill the combustion or
compression chamber referred to above with a fresh combustible mixture.at or
about the same time as the charge is being drawn in by the working piston, thus
we gain greatly increased power according to the length of the stroke of the piston
valve, to be hereafter described, and of the chamber referred to above, through
having. this space or chamber charged with combustible gases instead of burnt
gases or smoke.
According to our invention we describe in what manner the same can be performed
and worked.
We place in the said space or chamber beyond the working stroke of the piston,
a piston valve with a piston rod connected to a connecting rod which is worked by
a 'cam or cams on a counter shaft driven by the crank shaft at half the speed of
the crank shaft. The back end of the chamber or cylinder is provided with a hole
rather larger than the piston rod which admits air to allow the piston valve to
work freely, and round the inside edge of the said hole we turn a valve seating
and-round the piston rod or the piston valve we turn a corresponding seating so
that when the piston valve is drawn back by the cam or cams to the seating it forms
the valve and makes it air tight; or the same can be done with a piston and piston
rings.
The cycle of operations of our invention is as follows:-) We arrange the working
piston and the piston valve to meet at the exhaust port without quite touching, the
working piston then makes its outstroke, the piston valve makes its backward
stroke into the seating before-mentioned each piston drawing in its respective
charge, thus entirely filling the cylinder with a combustible mixture. The piston
valve remains in its place during the time the working piston is making its in or
compressing stroke and also while it is making its outward or working stroke.
When the piston has completed its out-stroke the exhaust valve opens and both
pistons advance together and nearly meet at the exhaust port. The operation is
again repeated by the piston and piston valve separating and drawing in their
respective charges as before described.
On the front of the cylinder we fit a cover so that between the cover and the
front of the working piston a chamber is formed in which to receive the shock or
force of the unexpended energy left after the working stroke before mentioned,
The products of
"which is conveyed from the exhaust valve by a suitable passage.
combustion then pass out into the open air through a port in the cylinder. .By
5rfanother arrangement the unexpended force referred to passes into a separate
auxiliary cylinder or exhaust chamber with a working piston in it connected
to a clutch or ratchet on the crank shaft to assist the propelling power of
the engine.
According to another..arrangement which we now describe we dispense with the

page_text: piston valve and make the working piston by travelling different lengths accomplish
the same object. In this arrangement we fit a motion or guide block, running in
suitable guides, connected with a connecting rod to the crank. The said block is
formed hollow with a hole through the end for the piston rod to slide through.
On the end of the piston rod we fit a collar and on the piston rod we fit a spiral
spring, one end of which bears against the motion block and the other end against
the collar on the piston rod, thus holding the piston and motion block close together
during the compression stroke and the working stroke which is one revolution. On
the bottom of the motion block we fit a bracket carrying a bell crank lever, one
end bearing against the collar on the piston rod, the other end sliding through a
slot in the guide plate and passing backwards and forwards over a cam on the
counter shaft, which revolves at half the speed of the main shaft. The said cam
revolves as the lever is sliding over it and raises that end of the bell crank lever,
and the other end of the lever bears against the collar on the piston rod and com-
presses the spring and forces the piston to the bottom of the cylinder, thus discharging
the whole contents of the cylinder. On the charging or outward stroke the cam
releases the end of the bell crank lever and the spring draws the piston close to the
motion block which completes the second revolution. By this means we fill the
whole length of the cylinder with fresh combustible gases as before described.
Dated this Seventeenth day of June 1891.
AUGUSTIN FIDDES.
FRANCIS AUGUSTIN FIDDES.
COMPLETE SPECIFICATION.
Improvements in Gas Motor Engines.
We AUGUSTIN FIDDES and FRANCIS AUGUSTIN FIDDES, Engineers both of
Lewins Mead, in the City and County of Bristol, 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 :-
Our invention relates to improvements in gas motor engines and has for its object
the filling of the space or chamber in the cylinder beyond the stroke of the working
piston with a combustible charge to increase the power of the engine.
In gas motor engines we have found it advantageous to fill the combustion or
compression chamber referred to above with a fresh combustible mixture at or
about the same time as the charge is being drawn in by the working piston, thus
we gain greatly increased power according to the length of the stroke of the piston
valve to be hereafter described and of the chamber referred to above through
having this space or chamber charged with combustible gases instead of burnt gases
or smoke.
According to our invention which we show in the annexed drawings (referring to
Figures 1. 2. 3 and 4 part sectional elevation and plans respectively) we place in
the said space or chamber A beyond the working stroke of the piston B, a piston
valve with a piston rod D, connected to a connecting rod E, which is worked by
a cam F (or cams) on a counter shaft G driven by the crank shaft H at half the
speed of the crank shaft. The back end of the chamber or cylinder is provided
with a hole I rather larger than the piston rod D which admits air to allow the
piston valve to work freely, and round the inside edge of the said hole we turn a
valve seating, and round the piston rod or the piston valve, we turn a correspondingly
shaped projection J so that when the piston valve D is drawn back by the cam (or
cams) to the seating, it forms the valve and makes it air tight or the same can be
done with a piston and piston rings.
The cycle of operations of this engine is as follows:-
We arrange the working piston B and the piston valve C to meet at the exhaust
port K without quite touching, the working piston B then makes its outstroke, the

page_text: piston valve C makes its backward stroke into the seating before mentioned, each
piston drawing in its respective charge, thus entirely filling the cylinder with a
combustible mixture. The piston valve C remains in its place during the time the
working piston B is making its in or compression stroke, and also while it is making
its outward or working stroke. When the piston B has completed its outstroke
the exhaust valve opens and both pistons B, C, advance together and nearly meet
at the exhaust port. The operation is again repeated by the piston B and piston
valve C separating and drawing in their respective charges as before described.
According to another arrangement shown at Figures 5 and 6 we dispense with
the piston valve C and make the working piston B, by travelling different lengths,
accomplish the same object. In this arrangement we fit a motion or guide block L
connected with a connecting rod M to the crank. The said block L is formed
hollow with a hole through the end for the piston rod D to slide through. On the
end of the piston rod we fit a collar N, and on the piston rod we fit a spiral spring P,
one end of which bears against the motion block L, and the other end against the
collar N on the piston rod, thus holding the piston and motion block close together
during the compressing stroke, and the working stroke, which is one revolution.
On the bottom of the motion block we fit a bracket carrying a bell crank lever Q,
one end bearing against the collar N on the piston rod D, the other sliding through
a slot in the guide plate and presses upon a cam R on the counter shaft G which
revolves at half the speed of the main shaft H. The said cam R revolves as the
lever Q1 is sliding over it, and raises that end of the bell crank lever ard the other
end of the lever bears against the collar N on the piston rod D and compresses the
spring P and forces the piston R to the bottom of the cylinder thus discharging
the whole contents of the cylinder.
On the charging or outward stroke the cam releases the end of the bell crank
lever and the spring draws the piston close to the motion block, which completes
the second revolution. By this means we fill the whole length of the cylinder
with fresh combustible gases as before described.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In a gas motor engine, fitting a second piston with rod through back end, and,
working in the same chamber as that of the main piston in the manner shown in
the annexed drawings, as and for the purpose or purposes set forth.
2. The hereinbefore described means for increasing the power of gas motor
engines viz. filling the space or cylinder chamber beyond the stroke of the working
piston with a combustible charge.
3. The herein described arrangement of guide block L with rod D of piston
through same, bell crank Q operatable by cam on shaft G and spring P respectively
as set forth and substantially as shown at Figures 5 and 6 of the aunexed
drawings.
Dated
T
1001
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said A. Fiddes and F. A. Fiddes.