Note: Descriptions are shown in the official language in which they were submitted.
11043~0
1 DIAPHRAGM OF ELASTIC MATERIAL AND ARRANGEMENT
USING THE SAME
Background of the Invention:
This invention relates generally to elastic diaphragms
and more particularly it relates to a shaped diaphragm of
elastic or flexible metal material and to its arrange-
ment and application in different devices.
Conventional diaphragms of this type have different
shapes and fields of applications. In operation, the
known diaphragms are subject to excessive changes in shape
and consequently are prone to premature wear and damage.
Summary of the Invention:
.
It is, therefore, a general object of the present
invention to overcome the aforementioned disadvantages.
.
More particularly, it is an object of this invention
to provide a diaphragm of the above-described type which
is suitable for opening or closing hydraulic circuits or
for various controlling applications, for condensing fluid
materials~ and for lifting or compressing objects, and
which has a uniform basic form.
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1 A further object of this invention is to provide
such an improved diaphragm which can be manufactured of
different elastic materials such as, for example, of
natural or synthetic rubber, elastic plastic material or
of a flexible metal.
. Another object of this invention is to provide a
diaphragm which in any of its operative posltions exhib-
its minimum volumetric changes and is exposed exclusively
to compressive tensions.
An additional object of the invention is to provide
such an impr~ved diaphragm having a thickness which is
adjustable to any pressure conditions and which has,
therefore, an increased internal rigidity so that it seals
without the aid of additional structural elements.
In keeping with these objects, and others which will
become apparent hereafter, one feature of the invention
resides, in a diaphragm of an elastic material, in the
provision of a rotary symmetrical diaphragm body which
is shaped to form a peripheral flange arranged in an at-
tachment plane, an annular conve~ vault extending between
the flange and a concave central region of the diaphragm,
the thickness of the vault-shaped portion of the diaphragm
body increasing from the flange toward the central por-
tion, the central portion being movable between two limit
. .
1104~38~
1 positions and the space between the vault-shaped portion
and the attachment ~lane having a substantially uniform
cross-section in any position of the central portion.
The diaphragm characterized by the aforementioned
S features finds many applications. For example, it can
be employed as a stabilizer for lifting, stamping or
compressing devices. It is also applicable as a diaphragm
in a control drive or as a diaphragm in a shut-off or check
valve where it can be operated either mechanically or hy-
draulically. Finally, the diaphragm of this invention is
also applicable as a shut-off flap.
Another advantage of the diaphragm of this invention
is in the fact that it is operable from either side and
two opposite parts of the concave central region can be
employed as sealing surfaces. In another application,
the outer marginal portion of the diaphragm can be used
as the sealing surface. Furthermore, it is also pos-
sible to use on diaphragm of this invention to act as a
control diaphragm for adtuating another diaphragm connect-
ed thereto and employed as a sealing diaphragm.
The diaphragm of the invention has basically the
shape of a semispherical shell with an inwardly depressed
apex portion. This configuration has an additional ad-
vantage in that it permits to make the diaphragm of great
. 11~4380
1 variety of elastic materials such as an elastomer or
plastic, that means not only of materials which have
rubber~like qualities but also of elastically bendable
metal alloys. The reason for such an extended application
is the fact that during the movement of the diaphragm
there results only minute changes in shape. Consequently,
it is sufficient to move the diaphragm with a relatively
small stroke to obtain a sufficient throughflow cross-
section when applied, for example, in a ~alve.
The novel features which are considered as character-
istic for the invention are sçt forth in particular in the
appended claims. The invention itself, however, both as
to its construction and its method of operation, together
with additional objects and advantages thereof, will be
best understood from the following description of specif-
ic embodiments when read in connection with the accompany--
ing drawings.
. Brief Description of the Drawin~s:
Figs. la-lc is an axial section of the diaphragm of
this invention shown in different working positions;
Fig. 2 is an axial section of the diaphragm of Fiq. 1
shown in a reversed positlon;
Fig. 3 is a sectional view of a lifting cushion using
two juxtaposed diaphragms of this invention;
11(~4;~
1 Fig. 4 is an axial section of a thrust drive using
the diaphragm of this invention;
Fig. 5 is a sectional view of a gate valve using
the diaphragm of this invention;
Fig. 6 is a sectional view of another gate valve
in combination with a control device using diaphragms of
this invention;
Fig. 7 shows in a sectional view a housing of a gate
valve using the diaphragm of this invention;
Fig. 8 is a cross-sectional view of another embodi-
ment of a gate valve using an obliquely arranged dia-
phragm of this invention as a shutting element;
Fig. 9 is still another embodiment of the gate valve
using the diaphragm of this invention;
Fig. 10 shows in a sectional view a non-return valve
using the diaphragm of this invention;
Fig. 11 shows a sectional view of a diaphrag~ pump
of this invention;
Fig. 12 is a sectional view of a sealing flap using
the diaphragm of this invention as a sealing element; and
Fig. 13 is a modification of a sealing flap of Fig~
12.
Description of the Preferred Embodiments:
Figs. la-lc show respectively an axial section of a
.
~ 3 ~ 0
1 diaphragm 10 made o elastomer or of an elastic plastic
material or also of a flexible metal, in a rest position,
in an intermediate actuated position and in a limit ac-
tuated position. The shape of the diaphragm 10 as shown
in its rest position corresponds to the shape of its man-
ufacturing or vulcanization mold;
The diaphragm 10 has a shaped rotation s~vmmetrical
~ody provided on its circumference with a flange 12 de-
fining a clamping or attachment plane 12a. In the fol-
lowing description, the surface of the diaphragm facing
the attachment plane 12a will be designated as the inner
side 11, whereas the opposite surface is designated as
the outer side 13 of the diaphragm. As shown in Figs.
la-lc, the diaph~agm body 10 is shaped such as to form
at its marginal portion adjoining the clamping flange 12
an annular vault defined by the outwardly curved margin-
al annulus 15r and 14r bounded by the inner side 11 and
the outer side 13. The radius of curvature of the inner
i marginal side portion 15 is smaller than the radius of
curvature of the outer marginal side portion 14, so tha~
the thickness of the diaphragm body 10 uniformly increases
I from the flange 12 toward the central region M of the
diaphragm. As seen from Figs. la-lc the diaphragm 10
undergoes during the displacement of its bulged central
portion M from its normal position to its limit position
110~:38~
1 only a minute change and particularly any s~eezing and
rolling motions thereof are eliminated. The Figures also
make evident the fact that despite of minute deformation
of the diaphragm a relatively large stroke of the latter
can be achieved.
The convex curves l5L and 15R (relative to the at-
tachment plane 12 and the annular space R~ transit in
the central area M into a concave hulge which at the
lower side 11 of the diaphragm has a base of a diameter X.
Similarly, the curved marginal portion 14L and 14R on
the upper side 13 of the diaphragm 10 transit in the cen-
tral region M of the upper side into a concave depression
17 having a base of the diameter Y. Accordingly, the
marginal part Z is convex, whereas the central part Y is
concave.
As indicated by dot lines, the outline of the convex
annular part 14L and 14R intersect at an acute angle in
a center point MC on the center axis of the diaphragm
body. In the cross-section, the area between the outer
marginal surface portion 14 and the inner marginal surface
portion 15 of the a-nular wall has the configuration of
a helical section. As a consequence, the convex marginal
portions 14 and lS of the diaphragm body has in its rest
position the shape of a substantially circular section,
whereby by displacing the bulging central portion M towards
1~4L38(1
1 its limit position the circular section in the proximity
of the flange 12 changes its shape only negligibly. Thls
configuration of the diaphragm which corresponds to an
ideal form of a surface acted upon by a pressure both from
above as well as from helow is made possible by the great-
er elasticity of the outer range.
The intersection point MC in the center of the di-
aphragm is in the normal position according to Fig. 1
about 2/3 of its maximum stroke above the upper clamping
plane of the flange 12, whereas in the limit working po-
sition as shown in Fig. lc the point MC is about 1/3
of the stroke below this plane. From the intermediate po-
sition as shown in Fig. lb the center of the membrane
moves about 2/3 of the stroke upwardly and 1/3 of the
stroke downwardly.
As seen from Fig. 1, the central portion of the
outer side 13 of the diaphragm has a smaller concave region
Y than the central convex region X at the lower side 11
of the diaphragm. Both central regions Y and X are also
smaller in diameter than the width of the annular region
Z. It can also be seen from the drawings that more than
70 to 90~ of the upper side 13 of the diaphragm has the
CQnVeX vault. The reverse relation is on the inner side
11 of the diaphragm where the convex surface 15 is
110~3RU
substantially larger than the central region Y having a
concave configuration.
The diaphragm 10, as seen from Fig. 1, does not have
any rigid central region. Conventional diaphragms of
this type have a distinct rigid center area, and conse-
quently the central region cannot participate in the var-
iation of form defining the stroke of the diaphragm. The
changes of the form of such prior-art diaphragms take place
exclusively in the smaller annular marginal part of the
diaphragm body. In the diaphragm according to this in-
vention, the entire circular surface Fl of the diaphragm
body is its working surface. .In other words, each change
of the working position of the diaphragm results in a
simultaneous change of the form of the entire diaphragm
body. The largest stroke is made by the central point MC
of the diaphragm body, whereas toward the periphery the
stroke continuously decreases. The shape of the diaphragm
of this invention enables, therefore, a large stroke of the
: center region of the diaphragm whereby the change of the
20 , annular volume below the lateral vaulted region is rela-
tively small. This particular feature of the diaphragm
i according to this invention enables many-sided applica-
tions.
As seen from Fig. 2, the convex section 14 of the
11~ 80
l outer side of the diaphragm body extends over a radius R
of more than 90, whereas the concave central region re-
versely bulged into the form of a semispherical shell has
in the center of the diaphragm a radius R2 of less than
90. Figs. l and 2 further illustrate that the ratio of
the diameter D of the diaphragm body to its height H is
larger than 2.5 and smaller than 3.5.
The diaphragm of Fig. 2 has an inwardly projecting
flange 18 provided if desired with a reinforcement or
armoring l9 and with a smaller outwardly projecting flange
20. The arcuate or vaulted walls 14 and 15 start at the
flange 12.
Fig. 3 illustrates the arrangement of two diaphragms
10 having juxtaposed inner sides. The flanges of the both
151 diaphragms are clamped between a correspondingly shaped
ring 21 and outer tubular clamps 22 and 23 which hold the
whole unit together. The space between the two diaphragms
is filled with a pressure medium through the filling port
24. The arrangement according to Fig. 3 can be used,
for example, for lifting an object 25 supported on the
upper diaphragm lO or for damping its vibrations. The
lower diaphragm is supported on a cup-shaped support 26
attached by means of a flat iron plate 27 to a foundation
28.
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ll~ V
1 Fig. 4 shows an application of the diaphragm of this
invention in an adjustable drive. In this embodiment, the
bulging center portion at the inner side of the diaphragm
is extended to form a reinforcement 29 having an elliptical
cross-section, the periphery 30 of which lies below the
attachment flange 12. The surface of the elliptical re-
inforcement 29 transits into the convex vault of the in-
ner surface in a streamlined fashion so that the periphery
30 projects into the annular space R below the convex marg-
inal part of the diaphragm. A disk-shaped head 31 of a
metal rod 32 is emhedded in the elliptical central rein-
forcement 29 of the diaphragm. The clamping of the attach-
ment flange 12 is effected by means of clamping rims of two
housing parts 33 and 34. The diaphragm separates two
pressure chambers 35 and 36 in the housing and drives al-
ternately a pressure medium admitted through ports 37 and
38. Fig. 5 shows a gate valve including the diaphragm
10 of this invention in which the outer convex surface
portions 14R and 14L intersect at a center point MC. The
; 20 downwardly bulging central reinforcement 29 at the inner
side of the diaphragm acts as a shutting member which in
this embodiment, extends obliquely to the attachment plane
of the flange 12 and is provided with a metal reinforcement
31 embedded therein. The outer side has at the central
region a concave surface 17 si~ilarly as in the preceding
embodiment. The clamping flange 12 is clamped between a
- 11~80
1 lower housing part 39 and an upper housing part 40, the
latter containing a control device for the valve. The
two housing parts are screwed one to another and the
fluid flows through the main line in the valve in the
direction of arrow 41. A control liquid 43 is provided
between the upper side of the diaphragm and the inner
wall 42 of the upper housing part 40. A hand wheel 44
with a threaded spindle 45 engaging a threaded hole in
. the lid of the upper housing part 40 controls the movement
of plunger 46 projecting into the interspace filled with
the control liquid 43 and being sealed against leakage
by sealing rings 47, 48 and 49.
. When the plunger 46 is moved downwardly, it exerts
a pressure against the liquid 43 which acts against the
entire upper surface of the diaphragm 10 and forces the
same downwardly. As soon as the pressure acting on the
upper surface of the diaphragm via the plunger and the
liquid 43 exceeds the counterpressure of the medium flow-
ing through the main line in the lower housing part, the
vaulted part at the lower surface of the diaphragm closes .
the seat 61. When the plunger 17 is moved by the hand
wheel 44 upwardly, the pressure of the streaming medium :
acting against the lower surface of the diaphragm 10
exceeds the pressure of the control liquid 43 and the
. .
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1 bulging central part of the diaphraym is automatically
liftcd from the seat 61 and opens the passage. Due to
the fact that the diaphragm can be exposed to hydraulic
pressure on both sides thereof, the closing and opening
position of the valve can be very simply adjusted, The
diaphragm of this invention is applicable for pressures
up to 25 bars.
The diaphragms 10 and lOa used in the valve accord-
ing to Fig. 6 are provided similarly as the diaphragm in
Fig. 2 with pins 50 embedded in the bulging central part
thereof and projecting in the dîrection of the axis of
symmetry of each diaphragm beyond the clamping plane of
the flange 12. Instead of the pin which is provided with
outer threads 51 there can be used a sleeve embedded in
the bulging central part of the diaphragm and provided
with inner threads. This sleeve, similarly as in the
example of Fig. 2, can be embedded in the diaphragm by
means of a reinforcing head 52. The convex central section
16 of the inner side of the diaphragm cooperates with a
2Q matching abutment piece 53 one face of which is provided
with a complementary concave or cup-shaped recess in con-
tact with the diaphragm section 16. The radius of curva-
ture of the concave recess on the abutment piece 53 is
slightly larger than the radius of curvature of the convex
bulging central portion of the diaphragm. This difference
~..,._ ~
., 11~ 0
1 in size contributes to a reduced friction since upon com-
pressing the diaphragm the concave vault of its central
section 16 becomes somewhat flattened. A connecting
shaft 55 rests on the flat side of the a~utment piece 53
and is screwed to the central pin 52 of the diaphragm. The
shaft 55 connects the shutting diaphragm 10 to the con-
trol diaphragm lOa of a control device. The control di-
aphragm lOa is arranged in the same manner as the shutting
diaphragm 10 in the lower housing part 39 but is slightly
larger in diameter. The control diaphragm lOa is clamped
between the upper housing part 56 and a cover 57 by means
of a ring 58. The pin 50a of the control diaphragm lOa is
screwed to the other end of the connecting shaft 55 and
cooperates with similar abutment piece 53a. The upper
side 13a of the control diaphragm lOa is exposed to a
pressure of a control fluid fed through an intake port
69 in the cover 57. Another pressure fluid is introduced
into the space between the inner wall of the housing part
56 and the inner surface of the control diaphragm lOa to
regulate the compression of the control diaphragm.
Fig. 7 shows a valve having a housing 39 covered
with a cover 40 fastened to the housing 39 by screws. The
surface of cover 40 facing the diaphragm is shaped simi-
larly as the abu~nent piece 53 in Fig~ 6 to have a concave
recess 54. The diaphragm is controlled by a pressure
. _
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~ 80
1 ¦ fluid such as a pressure air or pressure water intro-
¦ duced against the upper surface of the diaphragm through
¦ the intake port 59 and the diaphragm is inverted to close
¦ the central passage in the housing 39.
¦ In the valve as illustrated in Fig. 8, the diaphragm
¦ according to Fig. 2 is arranged obliquely to the axis of
¦ the main passage o~ the valve housing 39 and moves per-
¦ pendicularly to an oblique valve seat 61. In this ar-
¦ rangement, the diaphragm abuts against the valve seat 61
¦ along the apex line 62 of the outer convex marginal por-
¦ tion 14 acting as the sealing surface, This apex line
¦ can be reinforced by pro~ections 63. The diaphragm is
¦ moved by means of a hand wheel 44 and a threaded spindle
¦ 45 which at its free lcwer end has a threaded boring 64
¦ engaging the thread of the pin 50 embedded in the diaphragm
I
¦ Fig. 9 il~ustrates a valve having the diaphragm 10
i ¦ arranged in a valve housing 65 made of a teflon block which
¦ is shaped, for example, by mechanical machining. This
teflon block is surrounded by two metallic half shells
' 20 I connected one to another by bolts 66 and 67. The abutment
¦ piece 53 cooperating with the bulging central portion of
¦ the diaphragm is also assembled of two halves screwed
together by bolts 68 and 68a. The apex of its bulging
central part on the inner side 13 has an extension 69
11(?~
1 ¦ provided with an undercut 70. A connection pin 71 is em-
¦ bedded in the extension 69 and is connected to a spindle
¦ 72. In addition, the abutment piece 53 engages the under-
¦ cut 70 so as to insure a reliable connection of the con-
¦ trol spindle 72 to the diaphragm. The adjustment of the¦ working position of the diaphragm is carried out by means
¦ of the hand-operated wheel 44.
¦ Fig. 10 illustrates the diaphragm 10 used as the
shutting element of a non-return valve having a housing
39 defining a main passage with an obliquely arranged
seat similarly as the valves in Fig. 8. The vaulted lat-
eral walls of the diaphragm are provided with juxtaposed
openings 73 and 14. The sealing contact line of the
diaphragm of Fig. 10 is similar to the apex sealing line
as described in connection with Fig. 8. A reinforcing
disk 31 is embedded in the bulging central portion of the
diaphragm. This reinforcing member may have a star-like
configuration projecting with its tips into the vaulted
portion of the diaphragm body.
Fig. 11 shows a diaphragm pump in which the Clange
of the diaphragm is clamped between the lower housing part
39 and the upper housing part 40. The flange 12 is sur-
¦ rounded by tching recesses in the housing part, whereas
17-
.
I
11~
1 the bulging central pa~t projects into the interior of the
upper housing part 40 and is provided with an embedded
threaded pin passing through the recessed abutment member
and threaded to a fork 75 provided with a pivot pin 76.
The pin 76 supports a crank lever 77 linked at the other
end to an eccentric pivot pin 78 on a driving wheel 79.
The intake of the fluid takes place at the intake port
. of a non-return valve in a direction indicated by arrow
80, whereas the discharge of the fluid is affected through
another non-return valve in the ~irection of arrow 81.
The passage between the two non-return valves communicates
with the variable space between the bottom of the housing
part 39 and the lower side of the diaphragm 10. The di-
aphragm pump can handle relatively large pressures such
as, for example, 10 bars.
.
Fig. 12 shows the application of the diaphragm of
this invention as a sealing element of a shut-off flap
82 supported in a housing 84 eccentrically by a rotary
shaft 83. Due to this eccentric arrangement the shut-off
. 20 flap defines a continuous sealing surface along its whole
periphery and reliably seals in both directions of flow.
For this purpose the flap 82 is provided along its peri-
phery with a groove 85 into which the flange 18 of the
diaphragm 10 snugly fits, whereby the outer periphery 20
of the flan acts as a sealing surface. The bulging
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1~4~8~)
central portion of the diaphragm is connected to the
center of the disk-shaped shut-off flap 82 by the connect-
ing pin 50.
Fig. 13 shows a modification of a shut~off flap in
which the shut-off disk 82 has an increased diameter with
respect to the disk of Fig. 12 and the diaphragm lOa of
this invention has a ring-shaped configuration with an
opening in its center and is secured to the marginal sec-
tion of the disk 82 to perform merely its sealing func-
tion. In the reinforced inner margin of the diaphragm
lOa there are embedded connecting pins 50 and 50a similar
to the pin 50 in Fig. 12 and are secured by nuts 86 and
86a to the disk 82. As long as no pressure fluid is sup-
plied into the main conduit, the outer rim 20 of the
diaphragm is only as a loose contact with the inclined sur-
face of the valve seat 81 and the flap can be easily op-
erated. If a pressure fluid is admitted into a conduit
in the direction of arrows 8~, the outer rim 20 sealingly
engages the surface 88.
20 ¦ It will be understood that each of the elements de-
scribed above, or two or more together, may also find a
useful application in other types of constructions differ-
ing from the types described above.
.
1~ 80
1 While the invention has been illustrated and described
a~ embodied in a diaphragm, it is not intended to be lim-
ited to the details shown, since various modifications
and structural changes may be made without departing in
S any way from the spirit of the present invention. .
Without further analysis, the foregoing will so fully
reveal the gist of the present invention that others can
. by applying current knowledge readily adapt it for various
applications without omitting features that, from the
standpoint of prior art, fairly constitute essential char-
acteristics of the generic or specific aspects of this
invention.
What is claimed as new and desired to be protected by
Letters Patent is set forth in the appended claims.
