IMPROVEMENTS IN GAS ENGINES AND IN APPARATUS CONNECTED THEREWITH
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Thomas Baldwin at the Office of
the Commissioners of Patents on the 14th October 1882.
THOMAS BALDWIN of Cheetham in the County of Lancaster Engineer
"IMPROVEMENTS IN GAS ENGINES AND IN APPARATUS CONNECTED THEREWITH
"
I place a movable valve or piston or movable block of any suitable material at
a suitable distance from the inner end of the pistons stroke and continue the bore
of the cylinder any suitable distance beyond the end of the pistons stroke when it
is farthest within the cylinder and the said valve or piston or movable block is
constructed so as to be gas and air tight and can be moved by means of a screw
fitted in a nut fastened to the sides of the cylinder or to the engine bed or other
suitable place by which means the valve or piston can be moved so as to give a
greater or less space or volume between the end of the working piston and the
inner end of the piston valve or block which is moved by a screw or other
convenient apparatus my object being to vary the volume of gas as may be
required.
This valve or piston can be moved by hand whilst the engine is either working
or at rest as desired and the space in which the valve or piston moves may be
greater or less or the same size as the diameter of the piston that is attached to
the crank of the engine by the connecting rod it may be square or any other
convenient form or shape but should be gas tight.
The valve piston may be actuated by the governer so as to give more or less
power to the engine as may be required by the use of one or more revolving
shafts wheels tappets levers screws or other mechanical appliances or the valve
piston may have water at its outer end confined between it and the end of the
cylinder or in any other suitable vessel and by means of a pump the valve piston
may be moved so as to give a greater or less volume between it and the working
piston of the engine.
When water is used a suitable arrangement will be mechanically attached to the
force pump so as to force water in or out at will or be actuated by the governer
for that purpose
It will require less power to move or regulate the valve piston if it is moved
when the piston of the engine has very little pressure upon it or when making its
inward stroke.

page_text: One of the objects of the movable valve piston is to vary the power of the
engine between certain limits
The said variation is also accomplished by varying the length of the stroke of
the piston or by varying the length of the connecting rod or causing the cylinder
to be moved to or from the crank shaft.
To render this valve piston movable from the outer end of the cylinder I place
the valve or valves for admitting and emitting the gases to and from the working
cylinder at any convenient part of the cylinders exterior surface or attach the said
valve or valves thereto and actuate them in any suitable manner.
I also cause the compression valve or the exhaust valve to remain open before
compression commences either so that it may begin at the commencement of the
in stroke of the piston or at any suitable place before it gets to the end of that
stroke.
When the gas engine has a pump for feeding the working cylinder with gas the
variable space is effected by making the stud that revolves and works the pump
to slide to or from the centre round which it moves and also lengthening the
connecting rod of the pump or shortening it as may be desired and also increasing
or decreasing the volume at the end of the working piston of the engine.
In the case where compression of the explosive gases does not take place before
ignition the valve piston or block before named is used to increase or decrease the
volume at the end of the pistons stroke and the residual products of combustion
are driven out during the in stroke of the piston excepting those residual products
of combustion which remain in the space at the end of the instroke as before
named, when on the arrival of the piston at the end of the in stroke a valve opens
and the mixture of air and gas is admitted as the piston makes its return stroke
and is exploded at any convenient point of the out stroke so as to increase the
pressure on the working piston.
Another of my improvements consists of a small ram or piston pressed into a
suitable cylinder by the action of the engine so that the gas within it may be
compressed and thereby heated and allowed to escape at the proper time to explode
or cause the combustion of the mixed gases that are to drive the engine.
A sinall valve is fixed to the said small cylinder and pressed by a spring outside
the said cylinder or by a weight until the gas or gases within the cylinder
are raised to the required temperature for igniting the gases to drive the engine
I also use a cam or tappet or an eccentric to drive in the said ram of the
igniting cylinder at any given position of the pistons stroke and afterwards to
draw it out again to let in fresh gas or I use a small valve opening inwards to
admit gas into the small cylinder.