IMPROVEMENTS IN PUMPS FOR COMPRESSING OR EXHAUSTING AIR, OR OTHER GASES
Year: 1886

page_text: I, JAMES ATKINSON, Engineer of 3 Nassington Road, Hampstead in the county
of Middlesex, do hereby declare the nature of my invention for IMPROVEMENTS IN
PUMPS FOR COMPRESSING OR EXHAUSTING AIR, OR OTHER GASES, to be as follows:-
My improvements in pumps for compressing or exhausting 'air, or other gases,
consists in the arrangement and construction of the pump and its suction and
delivery valves, and also in the construction of a "safety" arrangement whereby
a pump ceases its action at any pre-determined pressure. The improvements in
construction are such as will enable cheapness of manufacture, freedom from
friction, quietness and certainty in action at high speeds, and compactness, to be
gained together with simplicity and durability of parts.
The pump may be a single-acting one of any suitable construction, fitted with a
piston or plunger working in the usual way. As close as possible to the end
(or side) of the pump, I place a valve box containing the suction and delivery
valves, which consist of thin concentric rings of suitable material (as hard bronze,
vulcanite &c); the lift of these valves is very small, and is defined by radial ribs
attached to a central boss at the centre of the valve circles, which form the guards,
and keep the valves concentric. These ring valves seat on suitable annular con-
centric openings in the seats; and the delivery valves seat being immediately over
the suction valves seat, the radial ribs on the former form the distance pieces
between the two, and also act as guards and guides to the suction valves, as
previously mentioned. The two valve seats together with the delivery valve guard
are so fixed on, and by, one central pin, as to be easily withdrawn, or replaced, in
the valve box together.
The safety apparatus consists preferably of a circular box of metal jointed at its
periphery, and having a suitable piece of india rubber, or other elastic material,
gripped between the joint, and forming a division or diaphragm between the two
portions of the box. On each side of this diaphragm I preferably place metal discs
attached to a suitable spindle, guided in the circular ends of the box, so that any
movement of the diaphragm due to the difference in pressure on its two sides,
is communicated to the spindle. On the side of the diaphragm opposite to that
of the pressure or exhaustion side, I make a communication through the box with
ID 0.71

page_text: the atmosphere, and also pass the said spindle through a suitable opening in the
box. This spindle, preferably bears against a suitable weighted lever, which
operates a sleeve working on a continuation of the same pin upon which the valve
Beats are fixed. This sleeve has projections on its surface towards the underside of
the valves to be lifted, so as to lift those valves off the seat, and maintain them
there until the pressure or exhaustion has decreased to that at which the weights
on the said lever allowed the lifting of the valves, thus permitting the pump to
recominence working.
The valves may be duplicated and the pump made double-acting, or a single set
of valves used in conjunction with a suitably proportioned annular space at one
end of the cylinder, formed between a trunk on the piston and the cylinder walls,
so that a delivery takes place twice in a revolution, to one suction.
It will be understood that these valves are very light, and as the air passing
through their seats issues on their inner and outer circumferences, they require a
very small lift, and may be driven at a high speed; they are therefore suitable to
be driven direct by, or in combination with, the gas engines described by me in
various letters patent, or by any other high speed motor.
When the pump is required to compress to a considerable pressure, or to exhaust
to more than a few lbs. below the atmosphere, the passage to the valves from the
pump is placed a little higher than the bottom of the pump, and a little water
allowed to pass into the pump, which fills the clearance space when the plunger is
down, and makes the pump deliver its full volumn; the suction valves seats are
raised up so that as soon as the plunger commences to return the water falls away
from the seats and little or none of it is delivered to pass into the suction inlet.
Dated this 1st day of February 1886.
COMPLETE SPECIFICATION.
Improvements in Pumps for Compressing or Exhausting Air or
other Gases, .
I, JAMES ATKINSON, of 3 Nassington Road, Hampstead, London, N.W. Engineer, 3
do hereby declare the nature of my invention for IMPROVEMENTS IN PUMPS FOR
COMPRESSING OR EXHAUSTING AIR OR OTHER GASES and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:―
My improvements in pumps for compressing or exhausting air or other gases 3
consist in the arrangement of the pump and its suction and delivery valves and
also in the construction of a 'safety" arrangement or "easing gear" by means
of which the pump is caused to cease its action at any predetermined adjustable

page_text: pressure of the delivery and recommence pumping as soon as this pressure falls, in
such a manner as to maintain the delivery steadily at the predetermined pressure
irrespective of the volume required so long as this volume does not exceed the
capacity of the pump; when the pump is employed for exhausting the "easing-
gear" can be employed in a similar manner to determine the pressure below the
atmosphere (or other standard) which is to be maintained.
An air pump and easing gear are shown in the appended sheet of drawings in
which Fig. 1 is a section through the pump and valves Fig. 2 is a separate sectional
view of the valves to a larger scale and Fig. 3 is a separate sectional full sized view
of the easing gear valve.
A single acting piston A. is fitted to the cylinder B and may be moved by any
suitable source of power. The cylinder B has a passage C leading in as short and
direct a manner as may be convenient to the space between two valve seats placed
in a valve box on the side of the pump; the upper of these D is the delivery valve
seat and the lower one E is the suction valve seat. The suction and delivery valves
consist of thin annular rings of any suitable material such as hard bronze, vulcanite,
&c, the lift of these valves is very small and is defined by recesses cut concentrically
in radial ribs which also guide the valves. The valve seats and guides are all
threaded on one central bolt which keeps them all concentric, binds them altogether
and enables them all to be removed or replaced together.
The thin annular valves seat themselves over annular openings formed in the
valve seats. The radial ribs on the delivery valve seat D form the distance pieces
between the seats as well as the guides and stops for the suction valves and the
separate piece F forms the guides and stops for the delivery valves.
The "safety" apparatus consists preferably of a circular box of metal O jointed
at its periphery and having a suitable piece of india-rubber or other suitable
material G gripped between the joint, forming an elastic division or diaphragm
between the two parts of the box. On each side of this diaphragm G I preferably.
place metal discs attached to a suitable spindle H guided in the end of the box O
so that it may slide upwards and downwards freely and so that any movement of
the diaphragm G due to difference of pressure on its two sides is communicated to
the spindle H one side I of the diaphragm G is in communication with the
atmosphere the other K may be placed in communication with the pressure of the
air when compressed or exhausted, and the thrust on the spindle H may be
counterbalanced by an adjustable weight or weighted lever, or the side K of the
diaphragm G may be placed in communication with the space L of the easing gear
valve shown in Fig. 3 and the spindle H bear directly on the sleeve M this latter
arrangement is shown in the drawings. The sleeve M has fingers or projections
on its surface towards the under side of the suction valves and slides on the end
of the central bolt which holds the valves and their seats together.
The easing gear valve is shown separately to full size in Fig. 3 in which the
pipe N leads from the pressure reservoir to the underside of the small valve P
which is pressed down to its seat by a spring which is adjusted so as to allow the
valve P to lift as soon as the pressure underneath it exceeds that desired in the
reservoir; the excess pressure passes by means of the pipe Q to the underside of
the diaphragm G lifting the spindle H and sleeve end, which by means of its fingers
holds the suction valves up from their seats; so long as these suction valves are
held up air is drawn into and expelled out of the pump B through them, and no
air can be delivered through the delivery valves. As soon as the pressure under-
neath the valve P falls below what required to lift it, it closes and any pressure
above it leaks away through the small leakage valve R thus allowing the diaphragm G
with its spindle H to fall allowing the suction valves to work in the ordinary way
and the pump to recommence delivering air.
If it is desired to start driving the pump without any load on it, presuming
there is pressure in the reservoir, this may be done by opening the starting valve S
which allows pressure to pass round the valve and hold up the suction valves until
this starting valve is closed. ⚫

page_text: This is very useful when the pump is driven directly by means of a gas engine
which might be difficult to start with a load on.
A safety valve T is shown on the cover of the valve box and is loaded to lift at
a pressure slightly above the desired maximum pressure, in the event of the safety
easing gear not operating or being improperly adjusted.
The valves may be duplicated and the pump made double acting, or a single set
of valves used in conjunction with a suitably proportioned annular space at one end
of the cylinder, formed between a trunk on the piston and the cylinder walls so
that a delivery takes place twice in a revolution, to one suction.
It will be understood that these valves are very light, and as the air passes them
on their inner and outer circumferences they require a very small lift and may be
driven at a high speed; they are therefore suitable to be driven directly by, or in
combination with, the Gas Engines described by me in various Letters Patent or by
any other high speed motor.
When the pump is required to compress to a considerable pressure or to exhaust
to more than a few pounds below the atmosphere, the passage to the valves from
the pump is placed a little higher than the bottom of the pump and a little water
allowed to pass into the pump which fills the clearance space when the plunger is
down and makes the pump deliver its full volume; the suction valve seats are
raised up a little so that as soon as the plunger commences to return the water
falls away from the seats, and little or none of it is allowed to pass into the
suction inlet.
•
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :
1. The general arrangement and construction of air pump valves as described
and illustrated.