IMPROVEMENTS IN APPARATUS FOR PUMPING WATER AND AIR, APPLICABLE ALSO IN PART TO HYDRAULIC MOTORS
Year: 1881

page_text: LETTERS PATENT to William Anderson, of Whitehall Place, and Wilfrid Airy,
of Queen Anne's Gate, both in the City of Westminster, for an Invention of
* IMPROVEMENTS IN APPARATUS FOR PUMPING WATER AND AIR, APPLICABLE
ALSO IN PART TO HYDRAULIC MOTORS."
PROVISIONAL SPECIFICATION left by the said William Anderson and
Wilfrid Airy at the Office of the Commissioners of Patents on the 22nd
February 1881.
WILLIAM ANDERSON, of Whitehall Place, and WILFRID AIRY, of Queen Anne's
Gate, both in the City of Westminster. "IMPROVEMENTS IN APPARATUS FOR
PUMPING WATER AND AIR, APPLICABLE ALSO IN PART TO HYDRAULIC MOTORS."
This Invention has for its object improvements in apparatus for pumping water
and air, applicable also in part to hydraulic motors.
A Patent has already been granted to us, No. 2851, in the year 1880, for pumps
and hydraulic motors, in which a screw of peculiar construction, and enclosed in a
cylindrical envelope is employed. We find that such apparatus in a modified form
is applicable for pumping air, and especially to compress air for the supply of blast
furnaces. For this purpose it is necessary to combine with the screw a receiver to
collect the compressed air, and passages to convey it from the receiver to wherever
it has to be heated, used, or applied. The screw for pumping air is immersed in
water in a tank, so that only the mouth is above. This screw is driven in the.
reverse direction to that in which it would be driven for pumping water, with the
result that it carries down air through the water, and discharges it at the lower
end into the receiver placed there to collect it in a state of compression due to the
depth of the water.
When higher degrees of compression are required than can be obtained conve-
niently with one screw, two or more may be employed. The mouth of the second
or following screw is then enclosed by a cover over the top of the screw tank, and
the air compressed by the first screw is admitted to the enclosure.

page_text: When our screws are used for pumping water or air, or as hydraulic motors, it is
an improvement to support the weight of the screw with its load of water by
suspension by the upper pivot, in place of by taking the weight of the apparatus
and load upon a footstep beneath the lower pivot. We do this in the following
manner: A bridge is provided over the top of the upper pivot, and the stem for
suspending the screw passes througb a bush fitting loosely in a hole formed in the
bridge to receive it. At the lower end of the stem there is an onion like bulb;
this enters a cavity in the upper end of the pivot of the screw, and is there retained
by a cap. The cap is securely bolted to the top of the pivot, and its under surface,
where it comes into contact with the bulb, and where friction occurs, is faced with
brass or other suitable material.
There is a cavity in the cover to contain oil to lubricate the bulb and the under
surface of the cap. The stem is square, and passes through a hole of corresponding
form in the bush, so that the stem may not turn, and it is drawn up to take the
weight of the screw by a nut which the stem receives at its upper end, where
it projects above the bridge.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Anderson and Wilfrid Airy in the Great Seal Patent Office
on the 20th August 1881.
<<
WILLIAM ANDERSON, of Whitehall Place, and WILFRID AIRY, of Queen Anne's
Gate, both in the City of Westminster. IMPROVEMENTS IN APPARATUS FOR
PUMPING WATER AND AIR, APPLICABLE ALSO IN PART TO HYDRAULIC MOTORS."
This Invention has for its object improvements in apparatus for pumping water
and air, applicable also in part to hydraulic motors.
A Patent has already been granted to us, No 2851, in the year 1880, for pumps
and hydraulic motors, in which a screw of peculiar construction, and enclosed in a
cylindrical envelope, is employed. We find that such apparatus in a modified
form is applicable for pumping air, and especially to compress air for the supply of
blast furnaces. For this purpose it is necessary to combine with the screw a
receiver to collect the compressed air, and passages to convey it from the receiver
to wherever it has to be heated, used, or applied. The screw for pumping air is
immersed in water in a tank, so that only the mouth is above. This screw is driven
in the reverse direction to that in which it would be driven for pumping water,
with the result that it carries down air through the water, and discharges it at the
lower end into the receiver placed there to collect it in a state of compression due
to the depth of the water.
When higher degrees of compression are required than can be obtained conve-
niently with one screw, two or more may be employed. The mouth of the second
or following screw is then enclosed by a cover over the top of the screw tank, and
the air compressed by the first screw is admitted to the enclosure.
When our screws are used for pumping water or air, or as hydraulic motors, it is
an improvement to support the weight of the screw with its load of water by
suspension by the upper pivot in place of by taking the weight of the apparatus
and load upon a footstep beneath the lower pivot. We do this in the following
manner: A bridge is provided over the top of the upper pivot, and the stem for
suspending the screw passes through a bush fitting loosely in a hole formed in the
bridge to receive it. At the lower end of the stem there is an onion like bulb;
this enters a cavity in the upper end of the pivot of the screw, and is there retained
by a cap. The cap is securely bolted to the top of the pivot and its under surface,
where it comes into contact with the bulb and where friction occurs, is faced with
brass or other suitable material.
There is a cavity in the cover to contain oil to lubricate the bulb and the under
surface of the cap. The stem is square and passes through a hole of corresponding
form in the bush so that the stem may not turn, and it is drawn up to take the
weight of the screw by a nut which the stem receives at its upper end where it
projects above the bridge.
In order that our said Invention may be most fully understood and readily
carried into effect, we will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a vertical section of an air compressor constructed according to our
Invention, and applicable to compressing air for the supply of cupolas, smith's fires,
blast furnaces, and for other uses.
The screw, as is described in the Specification of our former Patent, consists of
three parts, the core, the threads, and the envelope, and these together enclose

page_text: The thread of the screw is capable of developement, that is to say, when separate
from the core and envelope it can be spread out flat; indeed its form is that taken
by an annulus of sheet metal cut through radially, and then wound upon a core so
that the inner edge of the annulus may meet the core along a spiral line, the
annulus itself becoming a screw thread upon the core, and making with it obtuse
and acute angles.
In the working position of the screw the acute angle is downwards.
In the Figure, a, a is the core, and a¹, a¹ are pieces, by which the core is closed
at the ends; upon them the pivots or axes of the screw are formed; b is the thread
of the screw, and c is the envelope.
This screw, which may be of any convenient size, is immersed in a tank & which
contains water, or it might be other liquid; the screw is caused to rotate by the
application of power; e is the receiver; it is mounted in the tank and receives the
air from the lower end of the screw. The air is delivered into it by an opening
which the end of the screw enters as shown.
Figure 2 shows to a larger scale the way in which a joint is made to prevent the
escape of air from the receiver. There is a flange or ring upon the envelope of the
screw, and valve like flaps jointed on to the receiver are held in contact with the
ring or flange by springs. These flaps need not extend below the lowest water
level within the screw. fis the end of the pipe by which the air is led from the
receiver for use. The pressure of the air in the receiver will of course correspond to
the difference of level within and without.
Figure 3 shows a similar air compressor, but with the inclination of the screw
variable so that the receiver may be raised or lowered to adjust the pressure.
Figure 4 is a vertical section of some of the parts at the upper end of a screw
for pumping water or air. The Figure shows our improved method for supporting
the weight of the screw with its load of water (when water is being pumped) by
suspension at the upper pivot. Figure 5 is an elevation of some of the parts.
a is a bridge over the pivot b; and c is the suspending stem. The stem c is
squared and passes through a corresponding bush in a hole in the bridge. The
stem receives a nut c' at its upper end; the bush is free to play; c² is a bulb at
the lower end of the stem c; and 61 is a cavity in the pivot into which the bulb is
received; d is a cap to the cavity in the pivot, securely bolted on and provided
with a brass face where it comes into contact with the bulb c²; d¹ is an oil space
in the cover, from which the oil finds its way slowly to lubricate the frictional
surfaces of the bulb and cap.
e is the trunnion bearing; and f, f, the rollers contained therein, as is described in
our former Specification.
Having thus described the nature of our said Invention, and the manner of
performing the same we would have it understood that we claim,―
First. The combination forming an air compressor, and consisting of an inclined
screw having a developeable thread, a containing tank or vessel filled with water
or liquid, and an air reservoir, substantially as described.
Second. The method of supporting the screw by suspension by the upper pivot,
substantially as described.
In witness whereof, we, the said William Anderson and Wilfrid Airy, have
hereunto set our hands and seals, this 16th day of August, in the year
of our Lord One thousand eight hundred and eighty-one.