Pumps – Expansible chamber type – Having pumping chamber pressure responsive distributor
Reexamination Certificate
1999-06-11
2001-03-27
Freay, Charles G. (Department: 3746)
Pumps
Expansible chamber type
Having pumping chamber pressure responsive distributor
C092S169100
Reexamination Certificate
active
06206664
ABSTRACT:
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a compact pump comprising a diaphragm portion composing a pump chamber and a valve body disposed in a valve chamber which are integrated with each other.
b) Description of the Prior Art
A conventional compact pump having a diaphragm which is, for example, of a type having three pump chambers has a configuration shown in
FIGS. 1 through 4
.
In
FIG. 1
, a reference numeral
1
represents a compact DC motor, a reference numeral
2
designates an output shaft of the motor
1
, a reference numeral
3
denotes a case which is formed in a cup shape having a bottom surface attached to a side surface of an output shaft of the motor
1
with screws
4
, a reference numeral
5
represents a collar fixed to the output shaft
2
, a reference numeral
6
designates a driving shaft which is fixed to the collar
5
so that it is inclined at a predetermined angle relative to the output shaft
2
and its tip is located on a center axis of the output shaft
2
, a reference numeral
7
denotes a driving body having a hole
8
, a reference numeral
9
represents a cylindrical support portion which is formed integrally with the driving body
7
so as to extend downward from its center, and a reference numeral
10
designates a steel ball which is used to reduce friction between the driving shaft
6
and the driving body
7
. The support portion
9
is loosely fitted over the driving shaft
6
and when the output shaft
2
rotates, the driving shaft
6
is rotated in an inclined condition, whereby a peripheral portion having the hole of the driving body
7
reciprocally moves up and down relative to the center of the driving body
7
. A reference numeral
11
denotes a cylinder portion which is composed, for example, by forming three holes
12
in a plate like member as shown in
FIG. 2
, fixing three cylinders to these holes and forming three holes
13
.
A reference numeral
14
represents a diaphragm body made of a soft rubber, a reference numeral
15
designates three diaphragm portions having a form of hanging bells which are disposed at intervals of
120
degrees, integrated with one another and extended from the diaphragm body
14
, a reference numeral
16
denotes a driving portion located at a center of the diaphragm portion, a reference numeral
17
represents a head portion which is formed at a tip of the driving portion
16
by way of a thin neck portion, and a reference numeral
18
designates a valve body portion which is formed integrally with the diaphragm body so as to extend upward from its center and has, for example, a cylindrical form. The head portion
17
runs through the hole
8
of the driving body
7
and extrudes from a bottom surface of the driving body
7
, whereby the driving portion
16
is sustained by the driving body
7
. At locations corresponding to the holes
13
in the cylinder portion
11
(see FIG.
2
), holes
19
are similarly formed in the diaphragm body
14
(see FIG.
3
).
The diaphragm body
14
described above consists of the three diaphragm portions
15
, the valve portion
18
and other portions which are integrated with one another and made of an elastic material such as rubber.
A reference numeral
20
represents a lid body which serves also as a valve housing as shown in
FIG. 4
, a reference numeral
22
designates a hole which is formed to affix a valve, a reference numeral
23
denotes six air suction holes which are formed around the hole
22
, a reference numeral
24
represents a valve chamber portion which is formed upward over a center of the lid body
20
and a reference numeral
25
designates an exhaust hole which is formed in a thinned tip of the valve chamber portion
24
.
As shown in
FIG. 1
, the lid body
20
is combined with the cylinder portion
11
with the diaphragm body
14
interposed, and fixed to the case
3
with screws
27
utilizing the holes
26
formed in the lid body
20
, the holes
13
formed in the cylinder portion
11
and the holes
19
formed in the diaphragm body
14
so that three pump chambers
28
are formed by the lid body
20
and the diaphragm portions
15
.
The lid body
20
has a common chamber
29
which is formed in the valve chamber portion
24
and notch-shaped grooves
30
which are formed inside (toward a center of the lid body) the circumferential portions of the air suction holes
23
(circumferences of portions at which the pump chambers
28
are located) so as to communicate with the common chamber
29
. Accordingly, the pump chambers
28
are communicated at centers thereof commonly to the common chamber
29
. Furthermore, the valve body portion
18
is in contact with an inner circumferential surface of the valve chamber portion
24
so as to close communication paths.
A reference numeral
31
represents a valve body which is made of a soft rubber and has a shape of an umbrella, a reference numeral
32
designates a pole brace which is formed integrally with the valve body
31
so as to extend upward from its center, a reference numeral
33
denotes a head which is formed on a tip of the pole brace
32
so as to have a diameter larger than that of the pole brace. The valve body
31
is formed so as to have a size large enough to cover the air suction holes
23
and the pole brace
32
passes through the hole
22
so that the head
33
is located outside and will not come off the lid body
20
.
Now, description will be made of operations of the compact pump which is configured as described above. When the motor
1
is electrically energized and the output shaft
2
is rotated, the driving shaft
6
is also rotated, whereby points at ends of the outer circumferential surface of the driving body
7
sequentially move up and down to vibrate the driving portions
16
of the diaphragm portions
15
in a vertical direction with a phase difference of 120 degrees. That is, the diaphragm portions
15
make piston movements in the cylinder. The piston movements of the diaphragm portions periodically vary volumes of the pump chambers
28
. When the driving portion
16
moves downward and the volume is increased, an internal pressure of the pump chamber
28
is lowered, whereby the valve body portion
18
closes as it is brought into contact with the valve chamber portion
24
, whereas the valve body
31
opens to introduce air through the air suction holes
23
. When the driving portion
16
moves upward and the volume is reduced at the next stage, the internal pressure of the pump chamber
18
is enhanced, whereby the valve body
31
closes as it is brought into close contact with the lid body
20
, whereas the valve body portion
18
which closes the groove
30
of the pump chamber is opened to exhaust air from the pump chamber through the groove
30
, the common chamber
29
and the exhaust port
25
, from the pump chamber
28
through the common chamber
29
and the exhaust port
25
.
This compact pump performs a pump function by operating the three diaphragm portions so as to repeat the movements described above with the definite phase difference, thereby suctioning air through the separate air suction holes
23
and exhausting the air through the common valve chamber
29
and the exhaust port
25
.
The diaphragm pump which has the configuration described above combines the case
3
accommodating the driving portion which consists of the collar
5
attached to the output shaft
2
of the motor, the drive shaft
6
, the driving body
7
, etc. with the cylinder portion
11
, the diaphragm body
14
and the lid body (valve housing)
20
, and fixes these members as a whole with the screws. Furthermore, the case
3
, cylinder portion
11
, lid body
20
, etc. are made of a synthetic resin material and these members which are made of the synthetic resin material are fixed with metallic screws. Accordingly, each of these members made of the synthetic resin material expands with a coefficient of expansion larger than that of the metallic screws and is deformed at portions fixed with the screws and surroundings thereof i
Freay Charles G.
Gray Michael K.
Okenseiko Co., Ltd.
Pillsbury & Winthrop LLP
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