Improvements in Air Compressors, partly Applicable also to Air Motors.
Year: 1898

page_text: Date of Application, 27th Dec., 1898
Complete Specification Left, 27th Sept., 1899-Accepted, 2nd Dec., 1899
PROVISIONAL SPECIFICATION,
Improvements in Air Compressors, partly Applicable also to Air
Motors.
I, JOHN HUGHES, of 47, Victoria Street, Westminster, in the County of London,
Civil Engineer do hereby declare the nature of this invention to be as follows:-
This invention has reference mainly to air compressors and more particularly
to the type of compressors in which the inlet and discharge of an is controlled, or
mainly controlled, by mechanically moved valves; but part of the invention also
has reference to compressed air motors, where the supply and exhaust of air 18
effected and controlled by mechanically moved valves
The object of the present invention is, amongst other things, to provide a com-
pressor which, whilst it has a high duty as regards the volume of compressed air
discharged, for a given size, (and which is due largely to the employment of a
mechanically moved valve or valves for inlet and discharge) shall possess a high
mechanical efficiency, that is, shall have little clearance, and the fiction absorbed
by the working of the valves, shall be only small
These objects, together with other effects and advantages hereafter specified and
referred to, are accomplished by the unprovements according to this invention,
which are hereafter described.
The improved valves reforied to for governing the inlet of air, and discharge
of compressed air, ale of the cylindrical type, working in cylinders on the ends of
the compressing cylinder, with their axes at night angles to the axis of the
cylinder; about which axes they are adapted to be vibrated in the manner of a
Corliss valve And in connection with each of valves, there is employed a
secondary valve, to control the opening or outlet of the valve port through which
the discharge of compressed air is delivered
According to this invention, a valve is constructed with a port which conveys
the air to the cylinder from one end, while the compressed air is discharged from
the valve at the other, at which pait, as stated, the discharge poit 18 controlled
by a second valve, and the valve is actuated from the end at which the air enters
it, so that the operating mechanism does not work in or pass through a stuffing
box or an tight joint; which mechanism, say, is a short spindle, supported in a
suitable bearing, and having upon its end next the valve, a fork or clutch engag
ing with the central or other suitable part of the valve, by which the axial
reciprocations are given to it
In one form, the valve is a hollow cylinder, open at both ends, and having
within it a diagonal, angular, or similar septum or partition, dividing the
interior of the valve into two chambers or ports, each of which chambers has, in
the cylindrical shell, a longitudinal opening or port proper. Both these chamber
ports are open at the end, one to the an inlet, and the other to the compressed air
discharge conduit, while the peripheral ports, in action, are alternately brought

page_text: The
over the cylinder port, making thereby communication between the cylinder and
atmospheric air, and the cylinder and the compressed air discharge conduit
valve is actuated from the an inlet end, as referred to, and a seat is provided
between the end of its exlindical shell, and an annular ing or flange inside the
cylindrical valve case, and the valve 18 pressed on to this seat by the compressed
air. This beat constitutes a joint between the air inlet and discharge space
The degree, however, of this endwise pressure is limited by the employment of
a balancing piston, which is disposed or arranged in connection with the inlet end
of the valve, and is adapted to press the valve in a duection away from its end
Beat or point
In one arrangement this balancing piston works in a cylinder supported by
a suitable frame or support from the end of the valve casing, and presses directly
on the outer end of the valve actuating spindle, which say 18 rocked by a lever
or crank upon it, and this small cylinder is supplied with compressed an by a
small pipe from the compressed air supply or discharge conduit
In one construction, this relief or balancing cylinder and piston also serves as
a means of lubricating a joint between its end and the end of the valve spindle on
which it presses, and also, in some cases, the bearing of the valve spindle-which
say is supported on the end of the valve case-and joints generally of the moving
parts of the mechanism This is effected by filling the relief cylinder full of
lubricant, and providing a hole through the end of the piston, and through the
valve shaft to the working or moving surfaces of the parts The pressure of the
an in the cylinder on the lubricant in it, forces it into the working parts
And
At the opposite end of the au valve, there is a lift valve adapted to slide on
the main valve spindle or end, which closes the discharge exhaust passage of the
chamber, and this valve is normally pressed on to its sent on the main valvo
end (oi on to a seat in the valve case in proximity to the valve end) by a spung
in the manner of an ordinary lift valve The sping of this valve is preferably
light, and in order to limit its amount of opening, it is stopped positively
in order to avoid concussion in the opening action, the valve stem is relatively
large, and works in a suitable cvlinder, in the outer end of which is a small hole
to limit or choke the outlet of an in the opening of the valve, and so to cushion
the act of the valve stem coming on the stop, which is the end of the cylinder
It thus acts as a dash-pot This air hole also limits or chokes the entrance of an.
The end of the main valve case constitutes a compressed air discharge chamber;
and its end is closed by a removable cover, through which the main vaive and lift
valve are introduced, and taken out when requied
This construction enables all the parts where seuous wear is likely to take
place, to be easily and readily examined.
According to one arrangement of valves of this kind, their axes are arranged
vertically over the ends of the cylinders This arrangement enables a simpler
construction and disposition of an delivery and inlet, and also the balancing of
the annulus of the valve to be improved, as the valve can be duectly balanced
so that only its own weight bears on the annulus
A modification of valve of the Corliss type in which the inflow of air takes
place through one end of the valve, consists in providing a cylindrical valve of
the Corliss type, within the main valve, in lieu of the lift valve above described
for controlling the compressed an discharge outlet to the compressed air main
This valve may be concentric or eccentric in the main valve, and be worked by
separate gear from the outside in any suitable way
Another modification consists in providing a lift valve on the outside of the
mam valve casing, and carving the compressed au discharge by way of a lateral
port through the valve and valve casmg; which letter port 18 controlled by the
lift valve The air inlet, in this case, will pass in through the end of the valve as
above described.
In a further modification, the lift valve on the main valve end first described
can be mechanically worked through its own rotation with the main valve, and a

page_text: provision in the valve case, which, when the valve rotates is engaged and lifts the
valve off its seat
COMPLETE SPECIFICATION.
Improvements in Air Compressors, partly Applicable also to Air
Motors.
1, JOHN HUIs, of 17, Victoria Street, Westminster, in the County of London,
Civil Engineer, do hereby deolare the nature of this invention, and in what
manner the same 18 to be performed, to be particularly described and ascertained
in and by the following statement —
This invention has reference mainly to an compressors and more particularly
to the type of compressors in which the inlet and discharge of an 18 controlled, oi
mainly controlled, by mechanically moved valves; but part of the invention also
has reference to compressed air motors, where the supply and exhaust of air is
eftected and controlled by mechanically moved valves
The object of the present invention is, amongst other things, to provide a com-
pressor which, whilst it has a high duty as regards the volume of compressed an
discharged, for a given size, (and which is due largely to the employment of e
mechanically moved valve or valves for ulet and discharge) shall possess a high
mechanical efficiency, that is, shall have little clearance, and the fiction absorbed
by the working of the valve, shall be only small
These objects, together with other effects and advantages hereafter specified and
referred to, are accomplished by the improvements according to this invention,
which are hereafter described
The improved valves referred to for governing the inlet of air, and discharge
of compressed air, are of the cylindrical type, working in cylinders on the ends of
the compressing cylinder, with the axes at right angles to the axis of the
cylinder, about which axes they are adapted to be vibrated in the manner of a
Corliss valve And in connection with each of these valves, there is employed a
secondary valve, to control the opening on outlet of the valve poit through which
the discharge of compressed air is delivered
According to this invention, a valve is constructed with a port which conveys
the au to the cylinder from one end, while the compressed an 18 discharged from
the valve at the other end, at which part, as stated, the discharge port is controlled
by a second valve; and the valve 18 actuated from the end at which the au enters
it, so that the operating mechanism does not work in oi pass through a stuffing
box or a tight joint This mechanism, say, is a short spindle, supported in a
suitable beating, and having upon its end next the valve a fork or coupling engag
ing with the central o olhei suitable part of the valve, by which the axial
recipiocations are given to it
In one form, the valve is a hollow cylinder, open at both ends and having
within it a diagonal, angular, or similar septum or partition, dividing the
snterior of the valve into two chambers or ports, each of which chambers has, m
the cylindrical shell, a longitudinal opening or port proper Both these port cham-

page_text: The
beis are open at one end, one to the au inlet, and the other to the compressed air
discharge conduit, while the peripheral porta, in action, are alternately brought
over the cylinder port, making thereby communication between the cylinder and
atmospheric air, and the cylinder and the compressed an discharge conduit
valve is actuated from the an inlet end, as referred to, and a seat is provided
between the end of its cylindrical shell, and an annular 11ng on flange inside the
cylindrical valve case, and the valve is pressed on to this seat by the compressed
air acting on the opposite end This seat constitutes a joint between the air inlet
and discharge space.
The degree, however, of this endwise pressure is limited by the employment of
a balancing piston, which is disposed or arranged in connection with the inlet end
of the valve, and is adapted to press the valve in a duection away from its end
seat or joint.
In one arrangement this balancing piston works in a cylinder supported by
a suitable frame or support from the end of the valve casing, and presses directly
on the outer end of the valve actuating spindle; which, say, 18 rocked by a level
or crank upon it; and this small cylinder as supplied with compressed air by a
small pipe from the compressed air supply on discharge conduit
In one construction, this relief or balancing cylinder and piston also serves as
a means of lubricating a joint between its end, and the end of the valve spindle on
which it presses, and also, in some cases, the beaning of the valve spindle-which
say is supported on the end of the valve case and the joints generally of the moving
parts of the mechanism. This is effected by filling the relief cylinder full of
fubiicant, and providing a hole through the end of the piston, to the working oi
moving surfaces of the paits The pressure of the an in the cylinder on the
lubricant in it, forces it into the working paits
At the opposite end of the an valve, there is a lift valve, adapted to slide on a
cential bar or end of the main valve, which closes the discharge passage oi chamber
valve; and this valve is normally pressed on to its seat on the main valve end
(or on to a seat in the valve case in proximity to the valve end) by a sping, in
the manner of an ordinary lift valve. The spring of this valve is preferably
light, and in order to limit its amount of opening, it is stopped positively
And
in order to avoid concussion in the opening action, the valve stem is relatively
laige, and works in a suitable cylinder, in the outer end of which is a small hole
to limit or choke the outlet of an in the opening of the valve, and so to cushion
the act of the valve stem coming on the stop, which is the end of the cylinder
It thus acts as a dash-pot. This an hole also limits or chokes the entrance of air.
The end of the main valve case constitutes a compressed air discharge chamber,
and its end is closed by a removable cover, through which the main valve and lift
valve are introduced, and taken out when required
This construction enables all the parts where serious wear is likely to take
place, to be easily and readily examined.
According to one modification of valves of this kind, their axes are aanged
vertically over the ends of the cylinders. This arrangement enables a simpleı
construction and disposition of an delivery and inlet, and also the balancing of
the annulus of the valve to be improved, as the valve can be directly balanced
so that only its own weight bears on the annulus.
A modification of valve of the Corliss type in which the inflow of air takes
place through one end of the valve, consists in providing a cylinducal valve of
the Corliss type, within the main valve, in lieu of the lift valve above described
for controlling the compressed air discharge outlet to the compressed air main.
This valve may be concentric or eccentric in the main valve, and be worked by
separate gear from the outside in any suitable way
Another modification consists in providing a lift valve on the outside of the
main valve casing, and carrying the compressed an discharge by way of a lateral
port through the valve and valve casing; which latter port is controlled by the
.

page_text: lift valve The au inlet, in this case, will pass in through the end of the valve, as
above described
In a fun the modification. the lift valve on the main valve end fist described
can be mechanically worked through its own 1otation with the main valve, and a
provision in the valve case, which, when the valve 1otates 18 engaged and lifts the
valve off its seat, or by an independent longitudinal movement effected from
outside.
This invention is illustrated in the annexed diawings, in which Figure 1 18 a
longitudinal section taken though a compressing cylinder Figure 2 is a tiaud-
veise section through a valve and gear taken at the line A A Figue 1; and
Figures 3, 4 and 5 are details of the valve Figure 6 18 a valve diagram illus-
tiative of the action of the valve, and Figure 7 shews in cross section a modified
construction of valve
Referring to the drawings, 18 the compressing cylinder, and b are the end
covers, having within them (and in a horizontal cylinder in their upper parts or
halves) valve cylinders or casings c in which the valves work, and having then
axes disposed at 1ight angles to the axis of the cylinder, and f 18 a port forming
communication between these valve cylinders oi casings and the cylinder, and
through which the an passes to and from the cylinder.
dis the piston, and the piston 1od of the cylinder w
The air valves have two chambers, an inlet chamber and a discharge cham-
ber, both within the shell of the valve, and formed and separated from each
other by a septum or partition ; and thus septum 18 so arranged in the shell of
the valve, that the discharge chamber is of relatively small capacity The valve
has two ports in its shell J, running parallel with its axis, namely a port h¹ for
the inlet of air from the chamber h, and a port for the flow of an from the
cylinder to the chamber; and these chambers are open at their outer ends, to the
an inlet casing and outlet passage, respectively
118 the non-return or lift-valve on the discharge end of the body, which forms
a seat for its face and it is normally pressed on to its scat by a slight spring 1.
The valve is guided or supported by the projecting end of the stem m of the valve,
which runs through its centre, and a sleeve m¹ on the end cover n of the valve
casing, enclosing the passage or chamber o into which the air from the valve 18
discharged The other end of the valve rests on an internal projecting annulai
ledge on the inlet end of the valve shell c, which serves as a seat to the end
of the valve, the valve being pressed upon it by the air pressure in o, and making
an att tight joint between the chamber o and exterior of the valve body, and
the an inlet passage p A space is preferably provided between the valve body
and the valve casing cound the greater part of the valve circumferential surface,
and the bearing face of the valve which actually rubs on the internal face of the
valve casing is only that which exists about the ports and h
18 the cylinder, and q¹ its piston, by which the greater part of the pressure
acting on the end of the valve towards ¹, due to the pressure of the air in the
chamber o, 18 counter-balanced, and these parts relieved of fiction The cylinder
receives piessure from the compressed a conduit-o other part containing com-
pressed an by a pipe, and the passage, and it is charged with lubricant so
that the pressure upon it acts through a liquid, and this pressure, furthermore,
18 transmitted to the valve through a thrust plate borne upon by the piston g',
and operating spindle scarying the plate A space is provided between the
thrust plater and the piston y, and it communicates with the cylinder y by a
passage 3 and the oil under pressure thus lubricates the rubbing surfaces of the
plate and the piston q'.
The spindle s 18 supported in a bearing t, and is supported by and connected to
the metal casing p¹ enclosing the passage p, by a flange t'. This flange also
carries the cylinder q by the hollow semi-cucular web or bracket 3, which forms
a connecting piece between 1 and q.

page_text: "
The shaft is vibrated axially by the lever u, which is operated by an eccentue
or ciank from the engine shaft or other moving part, and the valve 18 operated
by a shaft though a coupling of the well known "Oldham type, and
forms a species of universal joint between the valve and its spindle, by which,
while the valve is free of its operating spindle as regards its power to adjust itself
in its cylinder, its action is tiue, and the friction and wear of the paits small
With regard to the valve 7, it is provided with a species of dash-pot both for the
opening and closing actions, namely, the hollow stem of the valve, which works
over the pin m, is closed at its outer end and 18 free to pass to and from it through
a small hole of regulated area at m³, and then also the sleeve m¹ also serves as a
dash-pot, an being allowed to and from it through a small hole m' of regulated
alea
"
The action of the valve 18 as follows.--On the outstroke of the piston d, the air
inlet port of the valve is uncovered when the piston has moved a very small
portion of its stroke, z, that equivalent to the lap shewn in the diagram, when
it begins to open rapidly, and is fully open to the point of the stroke indicated
on the diagram It then begins to close, and is closed at the end of the stroke
of the piston Then on the return stroke of the piston, the compressed an dis-
chuige poit moves towards the port f, and communication between the cylinde
and the chamber is made when the piston has moved a very small distance,
z. that equivalent to the lap shewn in the diagram: and it goes on opening
comparatively rapidly, and is fully open to the point of the stroke indicated in
the diagram, when it begins to close, and it is just closed at the end of the stroke
When the compression in the cylinder has reached the normal pressure in the
compressed an discharge chambei o, the non-ietuin valve will be lifted by the
pressure, and the an will pass from the cylinder by way of the port and
chamber, past the valve 1, into o, and the instant the port 18 covered and
closed, communication between the cylinder and the chamber is cut off, and no
back flow of compressed an can take place and the only compressed air that can
pass into the cylinder a, 18 that imprisoned in the chamber, on the opening of
the port to the port f at the next compressing stroke But long before this act
happens, the non-ietuin valve will have come upon its seat on the shell and
so back flow of compressed an to the cylinder is prevented The time between the
covering of the port ', when the valve begins to settle upon its seat, and its
next uncovering, is comparatively long, and hence it has plenty of time to come
gently onto it.
3,
With regard to the driving of the valve, by having the seat at the inlet end,
making an an tight joint with the casing, separating the compressed an parts
from the an inlet chamber, the diving of the valve from this-the inlet-end,
18 afforded, and so obviates the use of glands, and renders the operation simple
and easy
The valve is readily placed in position, or taken out upon removing the covern,
and drawing it out endwise through the opening in the end of the chamber o;
and when it is so removed, the whole of the parts can be inspected, for any purpose.
The friction of the valve in connection with the surfaces with which it iubs,
is due to the pressure forcing the face portion about the ports and h¹, to the
cylinder port face, and that of the end piessure pressing it on to its seat c
This
latter fiction is very small, as the end thrust 18 counterbalanced to a large degree
by the counter-pressure exerted axially on the valve by the balancing piston 2.
Hence the friction of the valve as a whole is diminished, as the actual face fiction
is relatively small
In some cases, especially in the case of large size of compressors, the non-ietuin
valve may be opened mechanically instead of automatically, and this may be done
by extending its stem through the cover n, and lifting it off its seat, and lowering
it onto it, by a bell crank diven from the engine, oi in any other suitable way.
By so operating the valve, a rise in the compression line of the diagram above the
normal pressure line, and consequent waste of energy, are obviated.
E

page_text: In lieu of the valve 7 resting directly on the end of the shell ; of the distribu-
tion valve, it may be made larger and rest on the valve casing e: but its use in
connection with the distribution valve would be precisely similar to that when
used directly on it-the valve
2
In the application of the invention as a distribution valve for an air motor, the
chamber will become the supply port, and the chamber h, the exhaust passage;
and it will be plain, that by suitable adaptation for distribution of air to and from
the cylinder, it is rendered serviceable for this purpose
In Figure 7, a modification is shewn in which, in a valve of the type described,
the back flow of an through the port when it is open to the port f in the com-
pression stroke, is prevented by a cylindrical valve within the main valve, in
lieu of a lift valve above described and shewn in the general diawing. This
valve will be worked, that 18, oscillated axially, from outside the casing, say by an
eccentric and level similar to that used for operating the spindle s
It is to be stated that the word "air" used herein, is to be understood as com-
prising ordinary atmospheric air, and also other analogous gases
Having now particularly described and ascertained the nature of this inven
tion, and in what manner the same is to be performed, I declare that what
I claim is.-
1 In an an compressor, a valve adapted to have an axial oscillating movement,
and constructed and adapted to cause the air passing to and from the cylinder,
to enter and be discharged at the opposite ends thereof, substantially as set forth.
2 In an air compressor, a valve adapted to have an axial oscillating move-
ment, constructed and adapted to cause the compressed air to be discharged at
one end, and having a valve in connection with it arranged and adapted to allow
the compressed air to flow from it, and to prevent the ietuin of such an to it;
substantially as set forth.
3 In an air compressor, a valve adapted to have an axial oscillating movement,
and having the an inlet through one end, and an air tight joint or seat at this
end and operated by the operating mechanism from this end, substantially
as set forth.
4 In an air compressor, a valve adapted to have an axial oscillating movement,
and having the air inlet through one end, and an an tight joint or seat at this
end, and pressed thereon by the pressure of air acting on the opposite end, and
operated from the said inlet end by the operating mechanism, and having a
halancing device by which the pressure on the said seat or joint is limited or
controlled, substantially as set forth
5 In an air compressor, a valve adapted to have an axial movement, and con-
sisting of a cylindrical shell having an opening at each end, through which the
air enters, and is discharged, respectively, and a septum or partition forming
inlet and discharge chambers, substantially as set forth
6 In an air compressor, a valve adapted to have an axial oscillating move-
ment, consisting of a cylindrical shell open at each end, and having a septum or
partition forming inlet and outlet chambers, a seat or face at the inlet end forming
an air tight joint, a non-eturn valve at the outlet or discharge end, and inlet
and outlet ports, arranged and adapted to operate as set forth with reference to
and shewn in the drawings
7 In an air compressor, a valve adapted to have an axial oscillating move-
ment, having a seat or face at the inlet end, forming an air tight joint, and a
balancing cylinder and piston acting upon a thi ust plate or device, and lubricated
by oil from the said cylinder, substantially as set forth
8 In an an compressor, a valve of the kind herein described, having an inlet
at one end, and operating and balancing mechanism in connection with said end;
arranged and adapted to operate as set forth with reference to and shewn in the
drawings
9 In an air compressor, a valve of the type herem described, having an air

page_text: outlet at one end, and a non-return valve thereon; arranged and adapted to
operate as set forth with reference to and shewn in the drawings
10 In a compressed air motor, a distribution valve having an axial oscillating
movement, and constructive characteristics substantially as specified, and adapted
to supply compressed air to, and exhaust an from the motor cylinde
Dated this 26th day of September 1899
CHEESBROUGHT & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool