Improvements in Apparatus for Compressing or Exhausting Elastic Fluids.
Year: 1899

page_text: Date of Application, 24th June, 1899
Complete Specification Left, 1st Dec., 1899-Accepted, 13th Jan., 1900
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Compressing or Exhausting
Elastic Fluids.
We, WILLIAM REAVELL, and REAVELL AND COMPANY, LIMITED, of The
Ranelagh Works, Ipswich, in the County of Suffolk, Engineers, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to improve the arrangement and construction
of apparatus for compressing or exhausting air or other elastic fluid, whereby
its efficiency is increased, economy is effected, and facility in making repairs
or renewing parts is afforded. The improved apparatus may be driven directly
by a steam or other motive power engine, by an electro motor, or by belt and
pulley, or other equivalent means, without departing from the nature of the
invention.
In one form of carrying out the invention a ring shaped casting is made
having four cylinders integral therewith, although we sometimes provide separate
castings for the cylinders, in which case the cylinders are suitably connected
to the ring shaped casting aforesaid. In either case, however, the cylinders
are placed in radial position at equal distances apart around the ring, so that
the two pairs are opposite each other; the inner ends being open their full
diameter, and those ends sufficiently far apart in the centre to give
sufficient room for the insertion and working of a crank shaft and
crank pin, with piston or connecting rods, each connected at its outer end to
a piston working in its corresponding cylinder, and its inner end suitably
connected to the crank pin, so that the one crank pin works all the four pistons
single acting in compressing or exhausting air in the cylinders. A central
hole of comparatively small diameter is cast at the outer end of each cylinder,
which serves the double purpose of allowing a boring bar to pass through
on the axial line of each pair of cylinders for boring them during the process
of manufacture, and for the reception of an air delivery valve. An outer cover
is fitted to close the exterior of each central hole, and an inwardly projecting
part thereof is combined with a spring to hold the delivery valve up to its
seat; and by removing each cover, access is readily had to the valve from
the exterior without disturbing any other parts. An annular belt chamber
and air passage, is cast in circular form around and connected with the outer
ends of the cylinders, thus forming a ring; and an inner ring or web with
flanges cast so as to connect the inwardly projecting cylinders together and
to form a water jacket, completes a rigid framework therefor. Transverse
ports are formed at the inner end of the cylinders, opening into the central
space or crank chamber which are just uncovered by each piston at the end
of its inward stroke; and a transverse space is formed at the extreme central
end of each cylinder, to permit the removal of each connecting rod sideways
from the piston. A slightly projecting flange on each face of the ring casting
is faced and bored to fit on a correspondingly faced and turned flange of a
bracket or the bed plate of the machine on the one side or inner face, and
for the reception of a circular door on the outer face.
The circular door last named thus encloses the central space or crank chamber,
and radiating orifices are formed in the door to admit air from the exterior.

page_text: so that the space or crank chamber.. also becomes the suction chamber, from
which air is supplied to the four radiating cylinders which open into it. A
central pin is fitted to the door, and a grid or circular valve having corre
sponding orifices is so mounted inside on the pin as to be capable of a slight
rotative movement when the pin is turned, to open or close the radiating
orifices aforesaid. Also attached to the central pin is a lever, which at one
end is connected to the piston of an air cylinder of small diameter, and at
the other end carries an adjustable balance weight. The air cylinder is open
at one end, and mounted upon the door with a pipe connection from the closed
end of the cylinder to the annular belt orláir passage previously mentioned,
so that the air pressure in both is the same. When air is compressed, (for
example), beyond a predetermined pressure, the piston is forced outwardly,
moving the lever, and turning the grid or circular valve so as to close the
radiating orifices in the door against the effect of the balance weight on the
lever; but when the pressure falls within the air passage and air cylinder,
the weighted lever returns the piston within the air cylinder, and the circular
valve opens the radiating orifices in the door, thus supplying more air to be
compressed within the cylinder. It will be seen, therefore, that the devices
described operate automatically to regulate the pressure of air to the desired'
amount; while conversely, the apparatus may be similarly used to bring about
a desired degree of exhaustion; and in order that the valve may not act too
quickly a suitable spring is combined with the weighted lever to partially
check its action. For marine purposes or where a weight is objectionable, how-
ever, spring pressure alone may be used for both purposes, and the weight
dispensed with.
The piston crosshead, to which the outer end of each connecting rod is attached,
is of cylindrical or roller form; and by means of a long slot through
the piston, and a port through the top of the connecting rod together
with its angular motion, a valve seat and valve is provided which
during a suitable part of the stroke establishes communication between
the crank or suction chamber and the cylinder above or beyond the
piston. The boss of the piston is bored in a cylindrical manner for the cross-
head as aforesaid, a part of the metal of the boss being cut away to allow
for the width and angular movement of the connecting rod; while a further
portion of the side of the piston is also cut away to permit the withdrawal
of the rod from its seating in the piston. Sufficient metal of the piston boss
is left, however, to surround and safely withstand the inward strain or pull
upon the rod on the return stroke, without fitting separate half brasses, or
other loose parts.
At the inner or crank pin end, each connecting rod abuts upon the bush.
of the crank pin, in the well known method used in three cylinder single acting
engines or air compressors; but in addition thereto, the segmental eye portion
of the rod, extending from each face of the rod, is turned to fit neatly into
an end socket or cap, which thus encloses the said eye portion of each face of
the four rods and take any pull from the rods. On removing the said caps or
one of them, and the other end of the rod being also free for withdrawal side-
ways from the piston as above mentioned, each connecting rod can in turn be
removed from its respective piston and cylinder when the crank pin is at
its furthest point therefrom; the transverse space formed at the extreme cen-
tral end of each cylinder being adapted for this purpose, as already described.
Moreover, the diameter of the circular door enclosing the crank or suction
chamber is made sufficiently large to enable workmen to accomplish this easily.
It will be understood that the apparatus may be mounted upon a suitable
bracket or brackets, or overhung upon a bed plate, provided with suitable
bearings for the shaft, and adapted to the means adopted for driving the same.
Also that convenient openings and connections are made for air and water
inlet and outlet; and that the automatic air pressure regulating valve operates
*

page_text: so that when the air is shut off by the circular valve or grid, a more or less
complete vacuum will be formed in the suction or crank chamber, thus pre-
venting any or but slight compression during the delivery stroke of the pistons ;
while, as soon as the pressure falls, air will be admitted through the radial
orifices by the action of the regulating valve, and again rapidly brought up
to the required pressure.
Ja of Tune 1899
FAIRFAX & WETTER,
37 & 39, Essex Street, Strand, London,
Agents for the Applicants.
COMPLETE
SPECIFICATION.
Improvements in Apparatus for Compressing or Exhausting
Elastic Fluids.
We, WILLIAM REAVELL, and REAVELL AND COMPANY, LIMITED, of The
Ranelagh Works, Ipswich, in the County of Suffolk, Engineers, 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 follow-
ing statement:-
The object of this invention is to improve the arrangement and construction
of apparatus for compressing or exhausting air or other elastic fluid, whereby
its efficiency is increased, economy is effected, and facility in making repairs
or renewing parts is afforded. The improved apparatus may be directly driven
by a steam or other motive power engine, by an electro motor, by belt and
pulley from power shafting, or other equivalent means without departing from
the nature of the invention.
In the further description of this invention reference is made to the accom-
panying drawings, in which Fig. 1 is a longitudinal sectional elevation of our
improved air compressing or exhausting apparatus, having four inserted cylinders,
and adapted for pulley driving. Fig. 2 is a plan of the same; Fig. 3 is a
sectional elevation taken through the air compressing end, partly on the line
Y-Y, Fig. 1, to show the arrangement of the cylinders and water jacket, (for
compression work), and partly through the line %% taken through the centre
of one of the cylinders. Fig. 4 is an exterior elevation from the pulley end
of the apparatus, and Fig. 5 is also an exterior elevation of the opposite or
cylinder end of the apparatus.
Figs. 6, 7, 8, 9 and 10 are detailed drawings on an enlarged scale of the
piston and connecting rod of each of the four air compressing cylinders employed,
with their connections to the single crank pin; and Fig. 11 is also a detailed
drawing (on a slightly reduced scale to the other details) of the outward end of
a cylinder with its delivery air valves, and means of access to the same from
the exterior.
Fig. 12 is an elevation of a circular door, enclosing the crank and suction
chamber, and having radial or other orifices for the admission of air to the
suction chamber. A grid or valve connected to a weighted lever and actuated
by the piston of a small air cylinder is pivotally mounted on the door to
open or close the radial orifices: and Fig. 13 is a section of Fig. 12. Fig. 14
is a sectional elevation of an air compressing or exhausting apparatus, in which
the four cylinders are integral with the ring shaped casting forming the water
jacket and annular air passage. Fig. 15 is a plan of a cover of the outward
end of a cylinder, and Fig. 16 is a section thereof showing a different form
of air delivery valve to that shown by Fig. 11. Fig. 17 is a section on an
enlarged scale of the air cylinder shown in Fig. 12.
In carrying out this invention, a ring shaped casting a is adapted to form

page_text: +
two separate annular chambers and a frame for carrying four equally spaced
radially arranged cylinders b, all opening inwards to an enclosed central space
forming both a crank and an air suction chamber c. The cylinders being
arranged in pairs, each pair upon the same axial line and at right angles to
each other, may be bored in position by a boring bar passing right across and
through openings in the casting a. In the smaller sizes of the apparatus the
cylinders may be cast integral with the ring shaped casting, a small central
hole 65 Fig. 14, being left in the outward end of each cylinder for the passage
of the boring bar. But in the larger sizes it is convenient to cast the cylinders
separately, and after boring them to turn their outer diameter to fit into seating
holes in the frame (as shown by the left hand half of Fig. 3) which are bored
on the same axial line as above described for the integral cylinders, outer
covers being fitted subsequently to close the holes through which the boring
bar is passed. The casting a is arranged to form two annular belt chambers,
one a cooling chamber or water jacket & surrounding most of the length of the
cylinders b', which in those separately cast have cooling surface ribs 62 formed
thereon; the other annular belt chamber e receives the air as compressed in
the cylinders through delivery valves f, one or more of which is or are inserted
in the cylinders outward end, as shown in Figs. 11 and 16. The belt chambers
and e thus form a self contained rigid circular frame a, surrounding and support-
ing the cylinders b, whether the latter are cast integral with the said frame,
or separately and fitted into the axial holes bored in the frame, as above stated.
A box shaped base plate g, having standards gl carrying a central boss g³
and circular end plate is provided, and the boss g2 is bored and bushed to receive
the crank shaft h. The circular end plate g³ is shown in Fig. 1 as cast integral
with the base g, and slightly overhanging the bed plate g, in order to be faced
and turned to receive the ring casting a where the latter is bored through (at
right angles to the axial lines of the cylinders) to form the crank chamber c.
A pedestal gis mounted on the base y and adapted to receive the further end
of the crank shaft hand pulleys he, h², but this part of the apparatus is liable
to modification if other means are provided for driving the shaft.
The ring casting a has a slightly projecting flange a¹, extending into the
crank and suction chamber c on each face of the casting, which is bored and
faced. This is fitted upon and secured to the stationary faced and turned circular
end plate g³, which thus carries the casting a and closes the aperture of the
chamber c on the driving or inner face; but on the opposite or outer face of
the ring casting, a circular door c is fitted and secured to the corresponding
flange a to enclose the central crank and suction chamber c. Radiating or
other orifices
are formed in the door c¹, or in a supplemental
cover thereon, which is adapted to carry a grid or circular valve c*,
on a central pin, the valve having corresponding orifices and arranged to be
capable of a slight rotative movement with the pin when the latter is turned by
a lever attached thereto. An adjustable balance weight c6 is fitted on the
lever, and a spring c is also secured thereto at one end, and to the circular
door at the other end, all as shown in Figs. 1, 2, 5, 12 and 13.
An air cylinder e¹, is mounted on the door c, and through the open end a
piston is adapted to bear upon the end of the lever, opposite to the adjustable
balance weight c, when compressed air is admitted to the cylinder from the
belt air chamber e through the communicating pipe c². The air pressure in the
belt chamber e and in the cylinder el is therefore the same, so that when air
is compressed (for example) beyond a predetermined pressure, the piston is
forced outwardly against the lever, and turning the grid or circular valve c
so as to close the orifices in the door against the effect of the adjusted balance
weight on the lever; but when the air pressure falls below that required in
the belt air chamber e, the weighted lever returns the piston within the air
cylinder e, and the valve c opens the orifices 2, thus supplying more air to the
suction air chamber c to be compressed within the cylinders b.

page_text: It will be seen, therefore, that while air is being compressed, the devices
described operate automatically to regulate its pressure to the desired degree;
while conversely, the apparatus may likewise be used to produce a similar degree
of exhaustion; and in order that the valve may not act too quickly, a suitable
spring such as c¹ is combined as shown with the weighted lever, to partially
check its action. For marine purposes, or where a weight is objectionable, spring
pressure alone may be used for both purposes, and the weight dispensed with.
The inward end of each radial cylinder b projects its full diameter into the
central crank and air suction chamber c, with those ends spaced sufficiently far
apart to give room for the insertion and working of the crank arm and pin h¹,
with the four attached connecting rods i, each secured at the other end to a
cylindrical or roller shaped crosshead ¹ which pivotally works in a suitable socket
boring in its corresponding piston block j; so that the one crank pin works all
four pistons single acting in compressing or exhausting air in the cylinders.
The cylinders project sufficiently into the suction chamber c to permit a port
or ports 63 to be formed therein, which ports are just uncovered by each piston j.
at the end of its inward stroke to admit air to its corresponding cylinder for the
in its outward stroke.
purpose of compressing
A space b is formed or cut transversely through the aforesaid projecting end
of each cylinder as shown in Figs. 3 and 14 to permit the removal or insertion
of each connecting rod i with its crosshead ¹ side ways from or to the piston
block j. This object is further facilitated by cutting away one side of the piston
block j, at the point indicated by in Figs. 6 and 8; but sufficient metal is
left, as shown in Fig. 10, to surround and safely withstand the inward strain
or pull upon the rod i on the return stroke, without fitting half brasses or other
loose parts.
In Figs. 7 and 10, a long slot or port 2 is shown on the outward end of the
piston j, and this together with a port 2 in the connecting rod crosshead ¹,
and the angular motion of the connecting rod i derived from the revolution of
the crank h¹, forms a valve seat and valve, which is alternately opened and closed
in a revolution of the crank shaft.
In
The inner end of each of the four connecting rods i, abuts upon the crank
pin h¹, in a similar manner to that followed in the well known three cylinder
single acting engines or air compressors, as shown in Fig. 10, a bush h³ being
interposed between the crank pin proper and the segmentally fitted ends of
the rods i. The rods are cut away radially, where they adjoin, in order to clear
each other in their various angular positions when they are working.
addition thereto, the segmental eye portion of the rod, extending from each
face thereof, is turned to fit neatly into an end socket or cap on each face,
(Fig. 9), which thus encloses the said eye portions of the four rods to take any
pull from them. A screw h secures the cap on the outer end of the crank
pin h¹, and on removing it from the tapped hole in the crank pin, together with
the cap aforesaid, while the piston end is also made free for withdrawal from
the piston block j at the point j¹, (as above mentioned), each connecting rod
can in turn be removed from its respective piston and cylinder, when the crank
pin is at its furthest point therefrom, the transverse space 64 formed in the pro-
jecting inner end of the cylinder being provided for this purpose as already
stated. Moreover the whole operation is performed after the removal of the
circular door c¹ the diameter thereof, as enclosing the crank or suction
0 chamber c, being sufficiently large to enable workmen to accomplish this with
facility.
When compressing air, the supply enters the four cylinders b through the
air ports b³, from the enclosed crank and suction chamber c; the pistons j in
rotation passing beyond the air ports, on their inward stroke towards the axis
5 of the crank shaft, to permit the inlet of the air to their corresponding cylinders.
As each piston in turn begins its return or outward stroke, it first closes its
air ports b³, and then compresses the air within the cylinder until its pressure

page_text: has increased sufficiently to open the non return delivery valve or valves f,
at the outward end of the cylinder, against the spring pressure of the valve,
which pressure may be varied to the desired degree by screw adjustment, or any
other known way. The compressed air is thus delivered through the valves f
into the annular or belt air chamber e, up to the end of the outward stroke,
and as the other cylinders in the series of four follow in close succession with
their charge of compressed air, the feed delivery into the chamber e is practically
continuous. But when the supply of air, so compressed, is greater than the
working requirements, the pressure rises in the air chamber e and the communi-
cating pipe e, so that the increased pressure forces the piston in the small
cylinder e down upon the end of the weighted and pivoted lever, which,
turning the attached grid or circular valve, closes the orifices c², and auto-
matically cuts off the supply of air to the suction chamber c. Conversely, when
the air pressure falls in the belt air chamber e, the weighted lever presses
the piston back into the air cylinder e and automatically opens the valve c³,
thus admitting air into the suction chamber c. The balance weight is
adjustable on the lever to suit the pressure required in the belt air chamber e,
and to prevent a sudden movement of the lever, a spring is provided as a
check. If a weight is objectionable, spring action may be substituted for
both purposes.
When the circular valve is closed automatically (as above described), a
partial vacuum would be formed within the cylinders, which would lead to
the air pressure in the suction chamber acting upon the crank side of the piston,
and thus reverse the well known continuous thrusting action of single acting
pistons upon the crank pin h¹. This is avoided by passing a little air from
the suction chamber through the port in the crosshead and the port in
the piston j, shown in Figs. 7 and 10. The port is so arranged that equili-
brium is established on the inward stroke of the piston, (when the piston is
moving towards the axis of the crank shaft), by the angular movement of the
connecting rod i, when the two parts and 2 come more or less into line, but
the passage is closed entirely on the outward stroke, when the piston j is moving
to compress air.
It will be seen in Figs. 3 and 11 that the delivery valves f at the outward ends
of the cylinders are quite accessible from the exterior through the holes in the
casting a, which are adapted as already stated for boring purposes; and these holes
are closed, and the surrounding belt chamber e made continuous, by means of
the covers which are suitably bolted on. Suitable water pipe connections d¹
are provided as convenient to convey water into and out of the belt cooling cham-
ber d, to provide a water jacket to the cylinders b.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. A four cylinder single acting apparatus for compressing or exhausting
elastic fluids, consisting of a ring shaped casting containing two annular chambers
one forming a water jacket and the other an air chamber, combined with four
cylinders radially arranged, each cylinder at its inner end opening into a
central space within the said casting, and each pair of cylinders placed on the
same axial line, suitable pistons and connecting rods with a crank shaft and
crank pin adapted and operating to drive the said pistons within the said cylinders,
air valves in or connected to the said cylinders at their outer end communicating
with the said air chamber, means for closing the said central space and for
regulating the supply of air thereto, and suitable pipe connections for air and
water, substantially as and for the purpose herein described and shown in
the drawings.
2. A four cylinder single acting apparatus for compressing or exhausting
elastic fluids, consisting of a base plate carrying an end plate, and bearings with

page_text: a crank shaft rotatable therein; a ring shaped casting having a central air chamber
mounted upon the said end plate so as to close one face of the said chamber;
a circular door, carrying a regulating air valve, arranged and adapted to close
the other face of the said chamber; four cylinders with suitable pistons and
connecting rods, adapted and operating to be driven by the said crank shaft
and to draw air from the said central chamber and expel it through valves at
the outer end of the said cylinders; and a surrounding continuous air chamber
communicating with the said valves, substantially as and for the purpose herein
described and shown by the drawings.
3. A multiple cylinder apparatus for compressing or exhausting elastic fluids
having in combination a ring shaped frame carrying the said cylinders in a
radial manner, a closed central space into which the inner end of the said
cylinders open and from which they draw a supply of the said elastic fluid,
suitable pistons with means for operating them in the said cylinders to compress
or exhaust the said fluids, means for automatically regulating the supply of
elastic fluid to the said closed central space, and suitable communicating passages
and valves at and from the outward end of the said cylinders for the said fluids
so compressed or exhausted, substantially as and for the purpose herein described
and shown by the drawings.
4. In an air compressing or exhausting apparatus, a ring shaped frame casting
consisting of two annular continuous chambers combined with four cylinders
radially placed oppositely in pairs and integral with the said frame, the outer
ends of the said cylinders and the frame having openings whereby each pair
of cylinders may be bored upon the same axial line, substantially as and for the
purpose herein described and shown by the drawings.
5. In an air compressing or exhausting apparatus, a ring shaped frame casting
consisting of two annular continuous chambers with circular openings through
the same, the said openings being arranged and adapted to be bored through on
two axial lines at right angles to each other for the reception of four corre-
spondingly turned cylinders fitted therein in a radial manner, substantially as
and for the purpose herein described and shown in the drawings.
6. In an air compressing or exhausting apparatus having a central crank
space, with multiple cylinders opening into the said space, the combination of
a crank pin and connecting rods i having an enclosing socket or cap em-
bracing the segmental ends of the said rods, a transverse space 6 formed in the
wall of the inner end of the cylinders, and a corresponding opening in the
piston block j, whereby either of the said connecting rods can be in turn trans-
versely removed or replaced from or to the said crank pin and piston block, sub-
stantially as and for the purpose herein described and shown in the drawings.
7. In an air compressing and exhausting apparatus, an automatic regulating
device comprising a closed suction chamber, a regulating valve pivotally arranged
and adapted to open or close orifices which communicate with said suction
chamber, a pivoted and adjustably balanced lever connected to the said valve,
an air cylinder and piston therein arranged and operating upon the said lever
under variable pressure to open or close the said orifices, and a pipe connection
from a source of elastic fluid pressure to the said air cylinder, substantially as
and for the purpose herein described and shown in the drawings.
T
1
T
1000
FAIRFAX & WETTER,
37 & 39, Essex Street, Strand, London,
Agents for the Applicants.