IMPROVEMENTS IN AIR-COMPRESSORS
Year: 1883

page_text: LETTERS PATENT to Frank Walter Scott of 44 Christian Street Commercial
Road East, in the County of Middlesex, Engineer for an Invention of
"IMPROVEMENTS IN AIR-COMPRESSORS "
PROVISIONAL SPECIFICATION left by the said Frank Walter Scott at the
Office of the Commissioners of Patents on the 4th October 1883.
FRANK WALTER SCOTT of 44 Christian Street Commercial Road East in the
County of Middlesex, Engineer IMPROVEMENTS IN AIR-COMPRESSORS
"
"
My invention has reference to that class of air compressors in which the air is
compressed in separate stages, such apparatus being constructed with one or more
chambers having suitable valves connected therewith for the admission and
retention of the air to be compressed.
And my invention consists in the use of an outer cylinder (which is fitted with
stuffing boxes and glands) within which cylinder is arranged a plunger fitted with
and carrying a small chamber in its interior, this plunger being worked up and
down in the cylinder by any suitable means of communicating a reciprocating
motion, such as for instance by a cranked driving shaft.
On the upstroke of the said plunger the air is drawn into the space thus left in
the cylinder, and on the return downstroke the air is compressed into the said
small chamber. On the next upstroke the compressed air in the small chamber
is forced into a large suitably arranged reservoir or chamber through a fixed tube
leading to such reservoir. This tube forming a guide on which the plunger works
There is a space between the small chamber and the inner surface of the plunger,
and water is kept in circulation through such space for the purpose of cooling the
small and large air chambers and surrounding parts during the working of the
apparatus.
The essential features of my said invention are the plunger carrying the small
chamber with the circulating water between the plunger and chamber, and the
further cooling of such plunger on its exposure to the air at each up stroke.
Also a hollow tube acting as a guide to the said plunger as well as conducting
the air compressed in the small air chamber to the larger reservoir or chamber,
which tube is also cooled by its exposure on the down stroke.
And the stuffing boxes and glands hereinbefore mentioned, indicating leakage at
once and admitting of being readily refitted (when this is necessary) as they are
accessible from the outside of the apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frank Walter Scott in the Patent Office on the 4th April 1884.
FRANK WALTER SCOTT of 44 Christian Street Commercial Road East in the
County of Middlesex Engineer “IMPROVEMENTS IN AIR COMPRESSORS"
My Invention has reference to that class of air compressors in which the air is
compressed in separate stages such apparatus being constructed with one or more
Chambers having suitable valves connected therewith for the admission and
retention of the air to be compressed.
And my Invention consists in the use of an outer Cylinder (which is fitted with
stuffing Boxes and glands within which Cylinder is arranged a plunger fitted with
and carrying a small chamber in its interior this plunger being worked up and
down in the Cylinder by any suitable means of communicating a reciprocating
motion such as for instance by a cranked driving shaft
On the up stroke of the said plunger the air is drawn into the space thus left
in the Cylinder and on the return down stroke the air is compressed into the said
small Chamber. On the next up stroke the compressed air in the small Chamber
is forced into a large suitably arranged reservoir or chamber through a fixed tube
leading to such reservoir the tube forming a guide on which the plunger works.
There is a space between the small chamber and the inner surface of the plunger
and water is kept in circulation through such space for the purpose of cooling the
small and large air chambers and surrounding parts during the working of the
apparatus.
The essential features of my said Invention are the plunger carrying the small
Chamber with the circulating water between the plunger and Chamber and the
further cooling of such plunger on its exposure to the air at each up stroke.
Also a hollow tube acting as a guide to the said plunger as well as conducting
the air compressed in the small air Chamber to the larger reservoir or chamber
which tube is also cooled by its exposure on the down stroke.
And the stuffing boxes and glands hereinbefore mentioned indicating leakage at
once and admitting of being readily refitted (when (this is necessary) as they are
accessible from the outside of the apparatus
Having thus stated the nature of the said Invention I will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying drawings in which are represented the parts of apparatus above
referred to
DESCRIPTION OF THE DRAWINGS
In Fig 1A shews the outer Cylinder which is fitted with a packing Box and
gland in which leather or any suitable packing can be placed.
B is the plunger which is caused to work up and down in the Cylinder A by
which means the air is drawn in on the up stroke through the valve C and is
compressed on the down stroke into the Chamber D through the valve E. On the
second up stroke the compressed air being retained by the valve E is forced
through the valve V into the pipe L which communicates with a reservoir or
chamber M or other suitable receiver. The heat caused by compression is kept
down by water running in at F into the Chamber G and out at H.
The pipe L also forms the guide for the plunger and the connection between it
and the chamber D is kept tight by a packing box as shown. By means of the
under the first plunger man ha

page_text: .
very moderate while in the reservoir or chamber M it will be very great X is
the driving drum for actuating the crank shaft Q
Fig 2 shews a method of obtaining another stage of compression on the same
plan. The operation is precisely the same as that in Fig 1 except that the
fixed pipe L is replaced by the plunger U which plunger being caused to move in
the opposite direction to the plunger B on its down stroke receives and retains
by means of the valve N, the air partly compressed in the chamber D and on its
up-stroke compresses the air finally through the valve O in the fixed pipe P into
the reservoir or chainber M or other suitable receiver.
The motions necessary for actuating these plungers in their proper directions are
obtained by cranks or excentrics set in suitable relative positions the whole being
actuated by any convenient means applied to the shaft Q
SS are the excentrics for working the plunger B and T is the excentric for
working the plunger U
Having thus described the nature of the said Invention and in what manner
the same is to be performed I hereby declare that I do not claim the compression
of air in stages except by the means hereinbefore described But what I do
claim is.
First The combined apparatus represented in Fig 1 for the compression of air in
stages and consisting of a plunger having a small air Chamber surrounded by
water and working on a fixed tube or guide through which the air is forced into
the reservoir or Chamber (or other suitable receiver) such tube being cooled by its
exposure on the down stroke of the plunger and the stuffing boxes and glands
being arranged so as to be readily accessible all substantially as and for the
purposes hereinbefore described
And secondly The modification of the said apparatus in order to obtain another
stage of compression as represented in Fig 2 and substantially as herein before
described.
In Witness whereof I the said Frank Walter Scott have hereunto set my hand
and seal this first day of April in the year of our Lord One thousand eight
hundred and eighty four.
Witness
WH. SPENCE
8 Quality Court
Chancery Lane
FRANK WALTER SCOTT (L.S.)