Improvements in or relating to Machines for Compressing Air and other Compressible Fluids.
Year: 1899

page_text: Date of Application, 19th Oct., 1899-Accepted, 23rd Dec., 1899
Improvements in or relating to Machines for Compressing Air and
other Compressible Fluids.
A communication from the PARKE & LACY COMPANY, a Corporation carrying on
business at 21 & 23, Fremont Street, San Francisco, State of California,
United States of America, Manufacturers of Mining Machinery.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to the class of machines for compressing air and other
compressible fluids.
The invention consists of various mechanical expedients adapted to, and cover-
ing, the diversified uses and conditions under which such machinery has to be
erected and operated, including the arrangement of the air compressor so that
the air supply may be taken either directly from the surrounding atmosphere or
from a distant and cooler source, or for the purposes of compounding, wherein
compressors are connected in series of two or more. The first one dicharging its
compressed air into the compressor cylinder of another compressor for the purpose
of further compression.
The main object of the invention is to provide a cheap simple and effective
air compressor adapted to various requirements.
Fig. 1 shows the form of mounting and power connections with the form of
compressor cylinder I preferably employ when the air is taken through a rearward
extension of the piston rod from the adjacent atmosphere.
Referring to Fig. 1. A is the motor cylinder A is its piston. rod. B is the
compressor cylinder, B₁ its piston rod.
C is a connecting rod of the motor cylinder piston A¹ and crank shaft. From
this rod C near one of its end projects an arm e forming with rod C a bell crank
To this projecting arm is suitably connected to be driven thereby, the com-
pressor piston rod 3 of the compressor cylinder B.
The crank shaft I) is provided with a suitable flywheel E and is journalled
in a suitable frame or bedplate.
The arrangement thus described transmits from the power piston, motion to the
compressor piston of peculiar character, whereby the motive power is applied in
a most desirable way, in that at the time when compression is most intense,
the direct action of the steam is applied to compression instead of, as is usual,
applying power stored up in the flywheel. In other words the piston of the
compressor reaches its extremes of reciprocation considerably ahead of the power
piston and while the power piston is being impelled by the direct action of the
steam and not while it is being carried over the "dead center" by the momentum
of the flywheel.
Referring next to Figs.
and 3.
Fig. 2 is the form of piston I preferably employ in the construction of cylinder

page_text: just described and under the conditions of taking the air supply from the
immediate surrounding atmosphere through a hollow extension of the piston rod.
Fig. 3 is a transverse section through line X of the form of piston shown in
Fig 2,
Fis the piston body and rod made hollow and provided with ring or annular
ports f.
G is a ring fitting the cylinder B snugly and connected to the piston by a
loose connection, permitting slight movement of the ring G independent of the
piston F.
The ring G is provided with a flange 9 overlaying the face of the piston F
sufficient to engage with and close or control the port or passage f. Suitable
means are provided for limiting the independent motion of the ring G, shown
as the broken or intermittent flanges f on the piston and g² on the ring G.
This construction permits of the ring G being placed in position by the
projecting portion of its flange g2 being placed opposite the vacant portion of
the flange of the piston and then pushed inwards against the piston and turned
with a partial rotation, so that the interrupted flanges f and g interlock.
Suitable means adapted to maintaining this relative position of the valve
ring G and piston F, while permitting the independent motion necessary to
close the port, is provided in pin H, which passes through the ring G, flanges f, g²
and body of piston.
,
Suitable packing rings may be provided in the piston as shown at I and
packing may also be provided in the valve ring G as shown at J.
Where necessary or desirable the piston may be made hollow and each face
provided with a port and a ring valve. This form is illustrated in Fig. 2; the
parts corresponding to G, f, g, f², g², in the latter form, are marked respec-
tively G¹, f, g', f³, g³, J¹. In this latter form the fluid may be admitted by a
hollow piston or other rod as shown at K Fig. 2.
Referring next to Figs. 4 and 5.
Fig. 4 is a longitudinal section of the rear half of a cylinder such as I preferably
employ under the conditions of taking air from a distant source by means of a
pipe or conduit connected to the cylinder inlet which is intermediate of the
cylinder ends.
Fig. 5 is a cross section of the cylinder showing the air inlet which is inter-
mediate of the cylinder ends.
L is a double walled compressor cylinder. The space between the double walls
forming a water space or jacket for the circulation of cooling water. An inlet
port L is provided, located approximately midway of the length of the cylinder.
For convenience of illustration but one end of the cylinder is shown in Fig. 4,
the other end being practically identical in construction.
M is a head suitably secured to the cylinder, it is also double walled to
provide for a water jacket. Free communication is provided between the water
jacket of the head with that of the cylinder for circulating the cooling water.
Suitable valve controlled outlets, one of which is shown at m, are provided in
each head for the exit of the compressed air, separated from the water jacket by
a suitable partition.
"
N is a
cage-piston formed of two plates nn separated by a distance approxi-
mately equal to the stroke. The plates nn are rigidly connected by any suitable
connection, one sucli is shown in the drawing as cast braces n¹ n'. Both ends of
the cage-piston being alike a description of one will suffice. When the parts
are assembled, comprises a piston head provided with a circumferential groove ²
for the reception of packing rings. It also has recessed into its outer face an
approximately concentric annular groove 3 and it is provided with an annular
valve controlled port or passage extending through from side to side of the
piston head n, of smaller diameter and concentric to groove ³..
An annular ring valve controls the port or passage n. It comprises a flat ring
sufficiently wide to cover the port 4 and extend to the groove i³.

page_text: The ring valve O is provided with a short annular stem o¹ which projects into
and is guided by the groove ³. The stem o¹ is provided with a radially project-
ing shoulder or flange o close to the ring. O, it is provided with perforations o³
for free exit of air. It may also have suitable packing as indicated at o.
Forming a part of the piston head is a detachable ring or annulus n³
approximately equal in exterior diameter with the piston head. A portion of the
inner surface of the ring forms a portion of the circumferential packing ring
groove n and the inner circular face of the ring forms one side of the annular
groove and being of somewhat smaller internal diameter than the external
diameter of groove proper, projects over shoulder o², thus forming a stop to
limit the motion of the annular valve 0.
The operation is as follows:
The piston is assumed to be just finished its stroke to the right as represented in
Fig. 2.
Access of air or gas to be compressed, is free at all time from the inlet port L'
to the interior of the cylinder L between the heads n n of the cage piston N,
consequently as the piston advances to the right, air will pour freely through the
annular port in the left piston head into the cylinder beyond the piston. Having
finished this forward stroke and starts back, the rear valve 0 closes and the
forward one opens, admitting air into the forward end of the cylinder and com-
pressing the air contained in the rear portion of the cylinder and forces it through
the valve controlled outlet m to a receiver or other desired place.
This operation is repeated with each stroke of the piston.
The construction herein illustrated and herein described accomplishes several
very desirable results in a simple and effective manner. It is desirable in this
class of devices that the heat generated by compression should be removed as
quickly as possible from the walls of the cylinder. In this device cold air has
free access to a much larger proportion of the inner surface of the cylinder
than in the case of a simple piston compressor.
Another desirable result of the present construction is that the inlet is adapted
to the attachment of a pipe whereby compounding is readily accomplished, also
gases or cold air can be led from receptacles or other sources, at a distance, results
difficult if not impossible in compressors in which multiple inlets are placed in the
cylinder heads.
It is extremely desirable that the inlet of air shall be as free and unobstructed
as possible, this is, obtained in the present device by the inlet L' and the
construction of the piston heads nn and valve 0 permitting the free and full
opening of the annular port nt. The opening of the valve 0 is immediate and
automatic at the commencement of the return stroke by the expanding of the
small body of compressed air forced in behind the valve stem o during its previous
stroke. The perforations o³ permits free passage of air with a small lift of
the valve.
Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondents and in what
manner the same is to be performed, I declare that what I claim is:-
1. In a compressor, a power cylinder and a piston therein, a compressor cylinder
and a piston therein, a crank shaft and a bell crank connecting rod connecting the
power piston crank and compressor piston by its attachment to the bell-crank.
2. In a compressor, a power cylinder and a piston therein, a compressor cylinder
and a piston therein, said cylinders being arranged with respect to each other in
the same vertical plane but their centers in different horizontal planes and a bell
crank connecting rod connecting the power piston and crank, and connecting the
compressor piston by its attachment to the bell-crank.
3. A compressor cylinder, a circumferentially unbroken piston therein, provided
with a port or passage and an exterior ring fitting snugly in said cylinder adapted
to control said port or passage.

page_text: 4. A compressor cylinder, a circumferentially unbroken piston therein having a
series of ports or passages in ring form and exterior rings fitting snugly in said
cylinder, adapted to control said ports or passages.
5. A compressor cylinder, a circumferentially unbroken piston therein provided
with a port or passage and an exterior ring fitting snugly in said cylinder,
provided with an inwardly projecting flange adapted to control said port.
6. A compressor cylinder, a circumferentially unbroken piston therein provided
with a port or passage, an exterior ring fitting snugly in said cylinder, adapted to
control said port or passage loosely connected to said piston whereby its motion
independent of the piston, is limited.
7. A compressor cylinder, a circumferentially unbroken piston therein provided
with a port or passage, an exterior ring fitting snugly in said cylinder, provided
with an inwardly projecting flange adapted to control said port or passage, loosely
connected to said piston whereby its motion independent of the piston, is limited.
8. A compressor cylinder, a circumferentially unbroken hollow piston therein
having a suitable inlet and provided with a port or passage and an exterior
ring fitting snugly in said cylinder, adapted to close said port or passage.
9. A compressor cylinder, a circumferentially unbroken hollow piston therein
having a hollow piston or other rod forming an inlet thereto and provided with
a port or passage and an exterior ring fitting snugly in said cylinder, adapted
to control the port or passage.
10. A compressor cylinder, a circumferentially unbroken hollow piston therein
having a suitable inlet thereto and provided with a port or passage and an exterior
ring fitting snugly in the cylinder having an inwardly projecting flange adapted to
control the port or passage.
11. A compressor cylinder, a circumferentially unbroken hollow piston therein
having a suitable inlet thereto and provided with a port or passage in each face,
an exterior ring on each side of the piston fitting snugly in the cylinder, adapted
to control said port or passage.
12. A compressor cylinder, a circumferentially unbroken hollow piston therein
having a hollow piston or other rod forming an inlet thereto, the piston provided
with a port or passage through each of its side walls and an exterior ring on each
side of the piston fitting the cylinder snugly adapted to control said port or
passage.
13. A compressor cylinder, a piston therein provided with a port or passage,
a ring valve provided with suitable packing rings fitting snugly in said cylinder
adapted to control said port or passage.
14. A compressor cylinder, a hollow piston therein having a suitable inlet
thereto and provided with a port or passage in each face, a ring valve on each side
of the piston having suitable packing rings and fitting snugly in the cylinder,
said ring valves adapted to control said ports or passages.
15. A compressor cylinder, a hollow piston having a hollow piston or other rod
forming an inlet thereto and being provided with a port or passage through each
of its side walls a ring valve on each side of the piston provided with suitable
packing rings fitting the cylinder snugly, adapted to control said port or passage.
16. A compressor comprising a cylinder having suitable outlets, a cage-
piston therein provided with a valve controlled port in each end thereof, com-
municating with the interior of the cylinder on opposite sides and an annular
recess or pocket exterior to and separate from said port, in which the stem of the
valve is guided.
17. A compressor comprising a cylinder having suitable outlets and an inlet
port approximately midway of the ends, a piston therein having a valve con-
trolled port in each of its faces and an annular recess or pocket, exterior to
and separate from said port, in which the valve stem is located and guided.
18. A compressor comprising a cylinder having a valve controlled outlet at
each end and an air inlet intermediate thereof, a piston therein having a through
passage and a ring valve on each face controlling the opposite ends of said

page_text: passage, the stem of which is guided in an annular recess or pocket exterior to
and separate from the passage.
19. The combination with the piston of a compressor having an annular port,
of a ring valve controlling the port, said valve having a stem projecting into a
Fecess or pocket in the piston exterior to and separate from the port.
20. The combination with the piston of a compressor having an annular passage,
of a ring valve controlling the passage having an annular stem projecting within
the body of the piston and provided with a radial projection, and a ring detachably
secured to the piston adapted to engage with the radial projection whereby the
movement of the valve is limited.
21. The combination with the piston of a compressor having an annular port,
of a ring valve the stem of which forms an annular piston in a recess or
pocket whereby air forced into said pocket by previous compression assists the
operation of the valve.
22. The combination with the piston of a compressor having an annular passage
of a ring valve of L section having an annular stem radially perforated near
its outer end to facilitate the passage of air.
Datad this 10th day of Dar 1800
BOULT, WADE & KILBURN,
Agents for the Applicant.