Improvements in Air-compressors.
Year: 1892

page_text: Improvements in Air-compressors.
I, RICHARD SCHRAM, of 17ª Great George Street, Westminster, in the County
of Middlesex, Civil 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:-
My invention relates to air-compressors, and has for its object to improve the
construction and increase the efficiency and safety of such apparatus.
My said invention is illustrated in the accompanying drawings, in which :—
Figure 1 is a longitudinal central section through the compressor cylinder
showing also the connections therewith.
Figure 2 is a transverse section on the line x, x, Figure 1 looking towards the
right, and
Figure 3 is a partial section on the line y y Figure 1.
Like letters indicate corresponding parts throughout the figures.
A is the air-compressor cylinder ;
B is a cooling jacket;
C is the compressor piston.
The inlet valves for the air are arranged in a circle as indicated in Figure 2 in
each cylinder end. One of the inlet valves D is shown in section in Figure 1.
EE are the outlet valves which are placed in the top of the cylinder and conduct
to a chamber F which extends from end to end of the cylinder and communicates
with the delivery pipe G. The inlet valves are shown made with flat faces
bearing on flat valve seats, while the outlet valves shown are of the mushroom
type. Either set of valves may be made with flat or conical faces as may be
desired. The inlet valves are provided as usual with springs D₁ which assist in
closing the same instantly on the return stroke of the piston, the tension of which
springs can be adjusted by means of lock nuts D². To prevent the said valves
being drawn into the cylinder should they become broken or accidentally dis-
connected from their seats, I provide at each end of the cylinder a safety disc H.
These discs are secured to the cylinder ends by bolts H. They are provided
with a number of perforations H2 opposite each inlet valve to allow of the free
passage of the air into the cylinder. The outlet valves E are preferably provided
with hollow stems E' which are supported in suitable guides E2 projecting
downwardly from the covers E³. Both the inlet and outlet valves are provided
with guides a which are so proportioned that the total circumference of the outlet
openings between the said guides is equal to the circumference of the inner side of
the valve seat. By this construction I ensure that the air shall have a free inlet
through one set of valves and free outlet through the other set.
I cool the cylinder by allowing water to flow through the jacket as is usual in
such machines, but in addition to the external cooling device I arrange an
internal cooling device which comprises pipes b, b which enter the cylinder at each
end thereof and connect with the water tank c. The said pipes are fitted with
stop cocks d, d for regulating the supply of water and with ordinary non-return
valves e e one of which is shown in section. Each time the piston makes a stroke,
water is drawn through one or other pipe into the cylinder, and this water is
prevented from returning, when the piston begins its return stroke, by the valve e.
One two or more water-inlet pipes communicating with the cylinder at the middle
of its length may be employed, instead of one at each end, or two or more water-
inlet pipes may be placed at each end of the cylinder, as may be most suitable.
The water used for internal cooling accumulates in the cylinder until the clearance
space is fully occupied, whereupon the excess water which is afterwards drawn into

page_text: the cylinder is forced out through the outlet valves into the chamber F. From
this chamber it is drawn off by a pipe f and conducted to the air receiver or to some
other suitable receptacle.
I raise the outlet valve seats a little above the level of the bottom of the
chamber as shown, so that the water forced through the said valves will flow readily
away from the valves along the bottom of the chamber and out through the
aforesaid pipe f.
The water tank c, from which the supply of water for cooling purposes is drawn,
is placed preferably above the cylinder, and may be filled" by means of a pump
worked by the driving gear of the air-compressor. The water may however be
obtained from any convenient source of supply under pressure.
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 :
The air-compressor constructed substantially as described with reference to the
drawings and operating. as specified
Dated this 16th day of June 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.