Improvements in Air Compressing Apparatus.
Year: 1898

page_text: Date of Application, 18th Feb.,
1898
Complete Specification Loft 3rd Nov 1808 Accented 3rd Dec.
1808
Improvements in Air Compressing Apparatus.
We, JOHN MCCLURE CALDWELL PATON, of Bloomsgrove Works, Nottingham,
Mechanical Engineer, and GEORGE HERBERT SHAW, of Trinity House, Tower
Hill, London, EC., Mechanical Engineer, do hereby declare the nature of this
invention to be as follows:-
It is a well known fact that gas and oil engines cannot be continuously run
with an overload and that the actual available power for constant running must
be within the extreme limit under which the engine may have been tested.
If, owing to the use of inferior gas or oil, or to leakage due to ordinary wear,
or for any other reason, the power developed by the engine be reduced, it is
evident that if such an engine is employed for driving an air compressor which
requires the full power of the engine to deliver a given volume of air at a
definite pressure, then such a decrease in the power of the engine as above
referred to must result either in the stoppage of the engine, or in a reduction
of the pressure at which the air will be delivered by the compressor. For some
purposes a reduction in pressure of the air while still delivering the same
volume thereof, may not be of much consequence, but in other cases it is most
important that the air should always be delivered at the full stipulated pressure,
the quantity of air delivered not being of so much importance.
Now this invention has reference to improvements in air compressing appar-
atus whereby such apparatus whilst capable of being driven by steam engines,
water-wheels, or other engines the power of which is not limited, is especially
adapted for use with engines the available power of which is strictly limited
as herein before described, as the construction is such that air can be supplied
thereby at the full pressure notwithstanding that the engine is working below
its normal power.
According to this invention the air compression cylinder is so constructed
that the volume of the clearance space left between the end of such cylinder
and the piston when the same is at the end of its compression stroke, is capable
of being readily varied to suit the power of the engine by which the compressor
is driven so that air can be delivered by the compressor at full pressure notwith-
standing decrease in the power of the engine below the normal power. As will
be obvious the air compression cylinder can be constructed in various forms to
enable this to be done.
According to one construction the inner end wall of the compression cylinder
is provided with a supplementary cylinder fitted with a piston that can be
readily moved backward or forward in its cylinder so as to thereby enable the
volume of the clearance space in the compressor to be correspondingly increased
or decreased at will.
In another construction the end wall or cover of the cylinder is made as a

page_text: plunger arranged to extend into the cylinder and formed with a flange through
which extend studs fixed to the cylinder end and fitted with adjusting nut the
arrangement being such that the end wall or cover can be moved endways in
the cylinder so that it can be placed at varying distances from the piston, when
the same is at the extreme end of its compression stroke, to suit requirement.
The effect of increasing the volume of the clearance space in the manner
described is to reduce the quantity of air delivered at each stroke of the piston.
The air compressed into the clearance space will re-expand at the commence-
ment of the return stroke and no more air will be drawn into the cylinder through
the suction valve until the internal pressure falls below that of the atmosphere.
The quantity of air taken in at each stroke being less than the full measure
of the cylinder, the power required for each revolution will be proportionately
less, while the reduced amount of air delivered will be maintained at the full
or original pressure.
Thus by reducing in the manner described, the quantity of air delivered by
a compressor with fixed stroke, we are enabled to maintain the full pressure of
the air delivered by the compressor notwithstanding that the available power
of the engine used to drive the compressor may fall below the normal amount.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Air Compressing Apparatus.
We, Jons MCCLURE CALDWELL PATON, of Bloomsgrove Works, Nottingham,
Mechanical Engineer, and GEORGE HERBERT SHAW, of Trinity House, Tower
Hill, London, E.C., Mechanical 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;-
-
It is a well known fact that gas and oil engines cannot be continuously run
with an overload and that the actual available power for constant running must
be within the extreme limit under which the engine may have been tested.
If, owing to the use of inferior gas or oil, or to leakage due to ordinary wear,
or for any other reason, the power developed by the engine be reduced, it is
evident that if such an engine is employed for driving an air compressor which
requires the full power of the engine to deliver a given volume of air at a
definite pressure, then such a decrease in the power of the engine as above
referred to must result, either in the stoppage of the engine, or in a reduction
of the pressure at which the air will be delivered by the compressor. For some
purposes a reduction in pressure of the air while still delivering the same
volume thereof, may not be of much consequence, but in other cases it is most
important that the air should always be delivered at the full stipulated pressure,
the quantity of air delivered not being of so much importance.
Now this invention has reference to improvements in air compressing appar-
atus whereby such apparatus whilst capable of being driven by steam engines,
water-wheels, or other engines the power of which is not limited, is especially
adapted for use with engines the available power of which is strictly limited

page_text: as herein before described, as the construction is such that air can be supplied
thereby at the full pressure notwithstanding that the engine is working below
its normal power.
For this purpose the air compression cylinder is so con-
structed that the volume of the clearance space left between the compression
end of such cylinder and the piston when the same is at the end of its compres-
sion stroke, is capable of being readily varied to suit the power of the engine
by which the compressor is driven so that air can be delivered by the compressor
at full pressure notwithstanding decrease in the power of the engine below
the normal power. As will be obvious the air compression cylinder can be
constructed in various forms to enable this to be done.
Fig. 1 of the accompanying illustrative drawings shows, partly in central
section and partly in elevation, the inner or compression end of one construc-
tion of air compression cylinder according to this invention.
According to this construction the end wall of the compression cylinder 2
is provided with a supplementary cylinder 3 fitted with a piston 4 that can be
readily moved backward or forward in its cylinder, as by a hand screw 5 and
fixed nut 5", so as to thereby enable the volume of the clearance space 6 in the
cylinder to be correspondingly increased or decreased at will to suit require-
ment. 7 and 8 are the suction and delivery valves of the compressor.
Fig. 2 is a similar view to Fig. 1 showing another construction in which the
end wall or cover 1 of the cylinder 2 is made as a plunger arranged to extend
into the cylinder and formed with a flange 1 through which extends studs 9
fixed to the cylinder end and fitted with adjusting nuts 10, the arrangement
being such that the end wall or cover can be moved endways in the cylinder so
that it can be placed at varying distances from the piston, when the same is at
the extreme end of its compression stroke, to suit requirement.
In a double acting compressor the compression may be made variable at both
ends or at one end only.
The effect of increasing the volume of the clearance space in the manner
described is to reduce the quantity of air delivered at each stroke of the piston.
The air compressed into the clearance space will re-expand at the commence-
ment of the return stroke and no more air will be drawn into the cylinder through
the suction valve or valves until the internal pressure falls below that of the
external atmosphere. The quantity of air taken in at each stroke being less than
the full measure of the cylinder, the power required for each revolution will be
proportionately less while the reduced amount of air delivered will be maintained
at the full or original pressure. Thus by reducing in the manner described, the
quantity of air delivered by a compressor with fixed stroke, we are enabled to
maintain the full pressure of the air delivered by the compressor notwithstanding
that the available power of the engine used to drive the compressor may fall below
the normal amount.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that
what we claim is;-
1. In air compressing apparatus, controlling the volume and pressure of the
air delivered therefrom by varying the volume of the clearance space between
the air compressing piston and the adjacent end of the air compression cylinder,
substantially as hereinabove described for the purpose specified.
2. In air compressing apparatus, an air compression cylinder so constructed
that the volume of the clearance space left between its compression end and
the piston, when the latter is at the end of its compression stroke, can be readily
varied to suit the power of the engine by which the said apparatus is driven,
substantially as hereinabove described for the purpose specified.
3. In air compressing apparatus, an air compression cylinder constructed

page_text: substantially as hereinbefore described with reference to and shown in Fig.
or in Fig. 2 of the drawings annexed.
Dated this 3rd day of November 1808
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent,