U.S. patent number 3,646,934 [Application Number 04/878,363] was granted by the patent office on 1972-03-07 for air compression equipment for therapeutic use.
This patent grant is currently assigned to W. D. Gale, Inc.. Invention is credited to Daniel S. Foster.
United States Patent |
3,646,934 |
Foster |
March 7, 1972 |
AIR COMPRESSION EQUIPMENT FOR THERAPEUTIC USE
Abstract
Self-contained apparatus for supplying cooled, dry, clean air
under pressure for therapeutic use. A motor and compressor is
contained in a sound-conditioned cabinet through which air is
circulated to cool the motor and compressor. Condensate from the
compressed cooled air is ejected into the cooling air through a
pressure relief valve.
Inventors: |
Foster; Daniel S. (Grosse
Pointe, MI) |
Assignee: |
W. D. Gale, Inc. (Detroit,
MI)
|
Family
ID: |
25371883 |
Appl.
No.: |
04/878,363 |
Filed: |
November 20, 1969 |
Current U.S.
Class: |
128/204.16;
165/122; 62/296; 165/47; 165/123 |
Current CPC
Class: |
F04B
35/06 (20130101); A61G 10/023 (20130101) |
Current International
Class: |
A61G
10/02 (20060101); A61G 10/00 (20060101); F04B
35/06 (20060101); F04B 35/00 (20060101); A61m
016/02 () |
Field of
Search: |
;128/212,191R,191A,1B,194,204,185 ;62/296,93,401
;165/120,121,122 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Dunne; G. F.
Claims
What I claim as my invention is:
1. Apparatus for supplying cooled air under controlled pressure
conditions for therapeutic use to a patient enclosure comprising a
cabinet, a sound-conditioned chamber within said cabinet, an air
compressor and compressor motor for driving said compressor and a
pressure regulating valve in said chamber, an air cooling tube in
said cabinet exterior of said chamber, conduit means connecting
said cooling tube between said compressor and valve, and said valve
to said patient enclosure, said pressure relief valve operating in
response to the pressure in said conduit connecting said pressure
relief valve to said patient enclosure, and means for circulating
cooling air across said cooling tube and thence through said
chamber.
2. Apparatus as defined in claim 1 in which the means for
circulating air through said chamber comprises a blower within said
cabinet exterior of said chamber, and a blower motor connected to
said blower and located in said sound-conditioned chamber.
3. Apparatus as defined in claim 2 in which said chamber occupies
the lower part of said cabinet leaving a compartment above said
chamber within said cabinet, said blower being mounted on the top
of said chamber and connected to said blower motor through the top
wall of said chamber.
4. Apparatus as defined in claim 3 in which one outer wall of said
cabinet has louvers therein communicating with said compartment,
the sidewalls of said chamber being spaced inwardly from the
sidewalls of said cabinet and defining air passages therebetween, a
port connecting said compartment with one of said passages, ports
connecting said chamber with both of said passages, and an outlet
port connecting said other passage to atmosphere.
5. Apparatus as defined in claim 1, said pressure relief valve
including a valve seat and movable valve member in position to
collect moisture condensed as a result of cooling compressed air in
said cooling tube, opening of said valve serving to discharge
condensate from the compressed air system through said valve.
6. Apparatus as defined in claim 5 in which said pressure relief
valve is located in a branch passage extending downwardly from a
horizontally extending portion of said conduit connecting said air
cooling tube and patient enclosure.
7. Apparatus for supplying air under controlled pressure conditions
for therapeutic use comprising a cabinet, a sound-conditioned
chamber within said cabinet, an air compressor and compressor motor
for driving said compressor in said chamber, means for circulating
cooling air through said chamber comprising a blower within said
cabinet, a blower motor connected to said blower and located in
said sound-conditioned chamber, heat exchange tubing connected to
said compressor and located in said cabinet in the path of airflow
induced by said blower, said chamber comprising the lower part of
said cabinet leaving a compartment above said chamber within said
cabinet, said blower being mounted on the top of said chamber and
connected to said blower motor through the top wall of said
chamber, said chamber have sound-insulated sidewalls spaced
inwardly from the sidewalls of said cabinet to define lateral air
passages therebetween, said blower communicating with one of said
passages, an air inlet from the bottom of said one passage to said
chamber, an outlet from said chamber to the top of said other
passage, said other passage having a discharge opening at its
bottom.
Description
BRIEF SUMMARY OF THE INVENTION
The present invention is intended for use in hospitals for
supplying air under controlled pressure for therapeutic use. It is
essential that this air be dry, bacteria free, and also free of oil
vapors and the like. Preferably, the unit is portable and comprises
a wheeled cabinet which may be moved from room to room.
A further requirement of the system is that it be very quiet in
operation, producing in general no more noise than an efficient
refrigerating unit.
The quietness is accomplished by mounting the air compressor and an
electric motor for driving the compressor in a sound-conditioned
chamber in the cabinet. Since this chamber is a sound-conditioned
chamber, dissipation of the heat generated by the motor and
compressor is a problem. This problem is taken care of by providing
an additional motor in the chamber and a fan or blower for
circulating cooling air through the chamber. This fan or blower is
illustrated herein as mounted on the top of the chamber which
contains the motors and the air compressor. Alternatively, it may
be mounted within the chamber.
The equipment is intended for providing dry, compressed air for
delivery directly to a patient for breathing at a controlled
pressure. The pressure is regulated by a pressure regulating relief
valve which is designed to open whenever the patient exhales and to
close as the patient inhales.
The compressor delivers the air at an elevated temperature as for
example 200.degree. F., and in order to cool the air for delivery
to a patient it passes through a coiled heat exchange tube,
preferably finned, which brings the air to approximately room
temperature. This cooling of the air condenses moisture from it so
that the air delivered to the patient under controlled pressure is
essentially dry.
The fan or blower circulates air around the motor and compressor
chamber and in addition, circulates air through the chamber where
it cools the motor and compressor, and more particularly, provides
the cooling action which reduces the temperature of the compressed
air as it passes through the heat exchange tube.
The pressure relief valve which controls the pressure of the air
delivered to the patient is arranged in conjunction with a
receptacle for the condensate so that the air which escapes through
the pressure relief valve carries with it the condensate and
delivers it into the air flowing through the chamber.
The air intake to the compressor includes an air intake tube
extending to the exterior of the cabinet where it is provided with
a filter unit having provision for ready replacement of filters
designed to remove airborne bacteria.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective of the equipment.
FIG. 2 is a side elevational view with parts broken away.
FIG. 3 is a vertical sectional view on the line 3--3, FIG. 2.
FIG. 4 is a diagrammatic view showing the airflow.
DETAILED DESCRIPTION
The air compression equipment is intended for ready mobility as
between rooms of a hospital, and is accordingly provided with
wheels 10 and a handle 11, supporting posts 12 being provided
adjacent the front of the unit.
As best seen in FIG. 1, the unit comprises a cabinet 14 which
conveniently may be made of sheet metal. The cabinet is generally
rectangular but adjacent its top rear portion there is an upwardly
extending enlargement 16 designed to contain certain equipment.
Referring next to FIG. 4 there is illustrated the flow of air
through the cabinet to a delivery structure including a filter. The
intake of room air is through a fitting indicated generally at 18
conveniently located in the top surface 20 of the cabinet and
including an upwardly extending tubular portion 22 having an
upwardly facing seat 24 on which is mounted a foraminous support
structure 26. The portion 22 is provided with a plurality of
outwardly extending pins 28 which engage in inclined slots formed
at the interior surface of a ring 30 carrying an inner ring 32
which is connected thereto by a flexible snapring 34. The
arrangement provides for removal of the rings 30 and 32 upon a
partial rotation thereof, and removal and replacement of a filter
element 36. The filter is intended to remove airborne bacteria and
may for example be a 10-micron filter. The compressor 40 draws air
through the filter 36 from which it passes along a conduit 42 to a
transparent receptacle 44. From the compressor 40 the compressed
air, which may at this time have a temperature of approximately
200.degree. due to compression, passes to a cooling coil 46 and
thence to a combined pressure regulating discharge valve and
condensate collector indicated at 48. Finally, the conduit 42 leads
to a final filter unit 50 mounted on the exterior of the cabinet
which provides a connection 52 for a conduit to lead the compressed
air to the point of use. A pressure meter 54 is provided which is
connected to the conduit 42 to give a direct reading of the
pressure at which the air is supplied.
Referring now particularly to FIGS. 2 and 3 the sidewalls 56 of the
cabinet are provided at their inner surfaces with sound-insulating
material 58. Within the cabinet is a separate sound-insulated
chamber 60 having sidewalls 62 provided at their interior surfaces
with sound-insulating material 63. The walls 62 are spaced from the
cabinet sidewalls 56 and provide spaces 64 and 66 therebetween for
flow of air into and out of the chamber 60. The bottom wall 68 of
the cabinet constitutes the bottom wall of the chamber and is
therein provided with sound-insulating material 70.
The compressor 40 is driven by an electric motor 72. The compressor
40 and motor 72 are located within the sound-insulated chamber 60.
The upper portion of the chamber 60 is closed by a top plate 74 so
that the motor and compressor are completely enclosed within a
sound-insulating chamber the front and rear walls of which are not
illustrated but which are also provided with sound-insulating
material similar to that illustrated at 58, 63 and 70.
While the chamber 60 is thus efficiently sound-conditioned, this in
turn creates a problem as a result of heating of the chamber due to
the operation of the compressor 40 and the motor 72. In order to
overcome difficulties occasioned by excessive heat within the
chamber 60, a circulation of cooling air is provided through the
chamber. For this purpose, adjacent the top rear of the cabinet
there is provided a louvered construction indicated at 76. Mounted
on the top plate 74 of the chamber is a blower 78 which has an
outlet port 80 through which the air is blown downwardly through
the passage 64 and into the chamber 60 through elongated ports 82.
The flow of air through the chamber is thence upwardly around the
motor and compressor and outwardly through similar elongated ports
84 adjacent the top of the chamber 60. This air, which has cooled
the motor and compressor, then moves downwardly and is discharged
through ports 86 located in the bottom of the cabinet.
The blower 78, which as previously described is located on the
plate 74 which forms the top closure of the chamber 60, is powered
by a motor 88 which is located within the chamber 60.
The cooling coil 46 is preferably in the form of a finned tube
which may be of substantial length such for example as 36 inches,
and which may be formed into sinuously curved multiple
convolutions.
The pressure relief and condensate discharge unit 48 comprises a
downwardly movable pressure relief valve having a stem 90 extending
through an opening in a cup 92 having a discharge orifice 94.
Within the cup 92 is a compression spring urging the valve upwardly
against its seat, with compression of the spring being adjustable
by threaded adjustment of the cup 92 on structure 96 which includes
the valve seat. The air as it passes through the heat exchange or
cooling structure 46 is cooled and condensate collects as a result
of the cooling. The condensate enters the assembly 48 above the
pressure relief valve and whenever the pressure relief valve opens,
the condensate is blown downwardly through the valve port and out
the discharge orifice 94.
In operation the pressure relieve valve is set to operate at a
predetermined value, for example, 50 p.s.i., such that the air
supplied through the external filter fitting 50 to the patient
falls below the set pressure during inhalation by the patient. When
the patient exhales pressure of the air within the system builds up
to the relief pressure set at the relief valve assembly 48 so that
the valve opens and discharges air to maintain the air pressure at
the set value. Accordingly, in normal operation the pressure
regulating valve 50 opens each time the patient exhales and
accordingly, there will be no opportunity for a substantial
accumulation of condensed liquid in the unit 48.
The relatively small amount of liquid which is thus discharged
through the orifice 94 upon each exhalation by the patient, is
preferably vaporized as it passes through the valve and is readily
evaporated by the air passing through the chamber 60. This
operation is rendered more effective due to the fact that the air
circulating through the chamber is substantially heated by the
absorption of heat from the motors 72 and 88 as well as the
compressor 40.
It will be noted that the pressure relieve valve unit 48 is also
located within the sound-insulated chamber 60 so that the slight
sound occasioned by periodic opening and closing of the valve and
the escape of air under pressure is efficiently silenced.
A switch 98 controlling the compressor motor 72 and the blower
motor 88 is preferably provided on the inclined panel surface 99 of
the cabinet for ready access.
The foregoing construction, the details of which have been
described, is characterized particularly in the effective silencing
of the operation by inclusion of the compressor and the two motors
within the sound-insulated chamber together with a circulation of
air through the cabinet which causes the air entering the louvered
wall 76 of the cabinet to pass over the finned heat exchange
structure 46 and thence through the chamber 60. The arrangement for
frequent and regular discharge of accumulated moisture from the
system through the pressure relief valve is also an important
feature, the moisture thus discharged being carried out of the
chamber 60 by the cooling air circulating therethrough. Finally, an
important advantage of the defined construction is the provision of
the readily removable and replaceable filter structure which is
effective to prevent entry of airborne bacteria into the
system.
* * * * *