Improvements in or applicable to Air Compressers.
Year: 1891

page_text: Date of Application, 3rd Apr., 1891
Complet: Specification Left, 31st Dec., 1891-Accepted, 2nd Apr.,
1892
PROVISIONAL SPECIFICATION.
Improvements in or applicable to Air Compressers.
I, CHARLES STUART, of Coventry in the County of Warwick, Mechanical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in or applicable to air compressers.
In carrying out my invention I arrange the eduction valves of air pumps or
compressers in such a manner that the filling of the air ports or passages is
avoided and what is known as churning is prevented.
For this purpose I place the eduction valves (preferably of circular form) at
each end of the working barrel of the pump or compresser fitted with the usual
reciprocating piston or plunger and I make the rod or rods of such piston hollow
for the purpose of admitting atmospheric air to either end of the said piston. My
hollow rods pass through the centre stems of the eduction valves which advan-
tageously work in stuffing boxes. If required the valves are kept up to their seats
by means of springs. The working barrel is surrounded with a water jacket for
the purpose of keeping the same cool in the usual manner.
Dated the 3rd day of April 1891.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or applicable to Air Compressers.
1, CHARLES STUART, of Coventry, in the County of Warwick, 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 :-
This invention relates to improvements in or applicable to air-compressers.
In carrying out my invention I arrange the eduction valves of air-pumps or
compressers in such a manner that the filling of the air-ports or passages is avoided
and what is known as churning is prevented.
For this purpose 1 place the eduction valves (preferably of circular form) at
each end of the working barrel of the pump or compresser fitted with the usual
reciprocating piston or plunger, and I make the rod or rods of such piston
hollow for the purpose of admitting atmospheric air to either end of the said
piston. My hollow rod or rods passes or pass through one or both of the eduction
valves which advantageously work in stuffing-boxes or guides. If required the
valves are kept up to their seats by means of springs. The working-barrel is
surrounded with a water-jacket for the purpose of keeping the same cool in the
usual manner.
To enable my invention to be fully understood 1 will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is a longitudinal section of an air-compresser provided with my
improvements; and,
Figure 2 is a section on the line ac, Figure 1.
a indicates the working barrel or cylinder of the pump or compresser, and the
casing around the same forming a jacket c for containing the cooling water.. The
jacket and the walls of the working barrel or cylinder are extended somewhat at
the ends so that, when the covers d, d' are applied, chambers e, e' will be formed at
the ends of the working barrel or cylinder.

page_text: f is the piston which is provided with the induction valves g, h, the latter
being connected to the former by stems i, i passing through the passages j, j
in the piston in such a manner that, when the set of valves his open, the
valve is closed and vice versa in a well known manner. is the piston-rod
which is provided with the passage communicating with the external atmosphere
and with a cross passage m in the piston, which latter passage also communicates
with the passages j, j.
n, o are the eduction valves which, as shewn, form the ends of the working
cylinder but the eduction valves may be inade smaller than the cylinder and seated
in the covers upon the same, provided the inner faces of the valves are flush with
the inner faces of the covers. The stem of the valve n slides in a guide in the
cover d and has the rod passing therethrough, whilst the stem of the valve o slides
in a guide in the cover d'.
p is a chamber formed in the jacket and serving as a receiver for the compressed
air which enters from the chambers e, el through the openings, is the outlet
for the compressed air, and s, s are the inlet and outlet for the cooling water to and
from the jacket p.
The stroke of the piston is such that the faces thereof practically touch the
adjacent eduction valves as the piston reciprocates, so that no air remains between
the said valves and the faces of the piston. It will thus be understood that, during
the reciprocation of the piston, all the air which enters the working cylinder
through the hollow rod k is compressed and escapes past the eduction valves n, o.
The said eduction valves are returned to their seats after being opened partly by
the air-pressure in the chambers e, e and partly by the air contained in the
chambers t, t in the covers behind the valve stems and which is compressed when
the valves are opened.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An air-compresser the eduction valves of which form the ends of the working
barrel or cylinder, substantially as described..
2. In an air-compresser the ends of the working cylinder of which are formed.
by the eduction valves, forming a passage through the piston-rod for admitting air
to the said cylinder, substantially as described.
3. In an air-compresser, the combination with the working barrel or cylinder, of
eduction valves forming the ends of the said cylinder, chambers in which the
eduction valves work and a hollow piston-rod for admitting air into the working
cylinder, substantially as described.
4. The manufacture and use of an air-compresser, substantially as hereinbefore
described and illustrated in the accompanying drawings.
Dated the 31st day of December 1901
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.