US2642091A

US2642091A - Elastic diaphragm

Info

Publication number: US2642091A
Application number: US792771A
Authority: US
Inventors: Morin Alexandre Henri
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-01-03
Filing date: 1947-12-19
Publication date: 1953-06-16
Anticipated expiration: 1970-06-16
Also published as: FR1003449A; GB674031A

Description

June 16, 1953 n A, H; Mol-N 2,642,091

ELASTIC DIAPHRAGM Filed Dec. 19, 1947 2 SheePs-Sheetl Filed Deo A. H. MORIN ELASTIC DIAPHRAGM 19, 1947 A2 sheets-sheet 2 Patented June 16, 195s y ELASTIC DIAPHRAGM Alexandre Henri Morin, Montlucon, France vApplication December 19, 1947, Serial No. 792,771

I In France January 3, 1947 1 My present inventionkhas for'its object an elastic diaphragm adapted to be subjected to the' pressure of any fluid and adaptedto'transmit any change in the pressure of said fluid to arcontrolling device, such Vas measuring instruments,

regulators, valves and similar devices.

The diaphragms already' known and used. have generally a corrugated wall asv an accordionpleated bellows cf metal vor of any elastiesub'- stance enclosing often threads or fabric. In all the diaphragme made up of a heterogeneous substance (e. g. rubber and threads) in which threads are enclosed inthe elastic substance, deformations are obtained through straightening of the threads. In fully metallic'diaphragms, deformations are obtained through a variation of curvature of the walls or of the corrugated surfaces and a straightening of 'the metal. In these conditions in order to avoid a lengthening of the wall and damage of the diaphragm, either the deformations and above all thetransmitted forces must remain limited or when these forces are large, they require the use of devices of large dimensions.

One object of my present invention is to provide an elastic diaphragm which is free of this inconvenience and is capable of working with large stresses, although having-small dimensions and leading consequently to 'devices of moderate volumes. y

Figure 1 is a diagrammatic representation illustrating the principles ofthe present invention;

Fig. 2 is a diagrammatic perspective view representing a further stageof thepresent invention;

Fig. 3 is a longitudinal sectionalview of one embodiment of the present invention;

Fig. 4 is a similar longitudinal sectional view showing another embodiment ofA the present invention; l

Fig. 5 is a transverse sectional view of the structure shown in Fig. 3;.

6 is a longitudinal sectional view of a modied form of the invention;

Fig. '7 is a transverse sectional view of the structure shown in Fig. 6;

Fig. 8 is a diagrammatic perspective view of the thread-like elements of one embodiment of the present invention;

Fig. 9 is a similar diagrammatic perspective view showing a modied arrangement of the thread-like elements of the present invention;

Fig. .10 .is a Vlongitudinal sectional View of one 6 Claims. (Cl. 137-793) form of diaphragm constructed in accordance -with the present invention;

Fig. 11 is a similar view of a modiedformjof a diaphragm;

Fig. 12' is a fragmentary sectional view ofi a diaphragm constructed in accordance with the f present invention;

Fig; 13 is a diagrammatic representation oi showing a. further step in the formation of the diaphragm;

Fig. 15 is a longitudinal sectional viewy of the device of the present invention showingthe connection between the diaphragm and the rigid members; f

Fig. 16 is asimilar view showing modified forms.

of the connection between the diaphragm and rigidy members;

Fig. 17 is a longitudinal sectional view of a de vice constructed according tothe present invention for actuating the lever; v l

Fig. 18 is a longitudinal sectional view of ay device embodying the principles of the` present invention applied to a valve;

Fig. '19 is a transverse sectional Viewk of the device of Fig. 21;

Fig. 20 isa similar transverse sectional View of` a modied form of device; i

Fig. 21 is alongitudinal sectional view showing a modied form of the present invention applied to a valve.r Y

Referring to Figures 1 and 2 of the drawings, it can be seen that when a thread a whose ends are fastened to pieces A and B is subjected to such forces as the forces P, which may be, for instance, 'at right angles to the thread, it tends to draw the pieces A and B nearer to each other. 1f the thread is nearly rectilinear, the forces which tend to draw the pieces A and B'nearer become very great, even if the forces P arev very small.

Suppose no w (Fig. 2) that, according tothe invention, a certainnumber ot threads a, forming one or several networks; are fastened to the pieces A and B on which each or them exerts a pull under the actionof elementary forces such as P; they will tend to'draw the pieces A. and B towards each other. If there is placed on the networks of threads a up to the pieces A and B, a fluid-tight lm b made of any elastic substance such as rubber for example, the wall thus made in the shape of a sleeve can be subjected to the pressure of any fluid either on the inner or on the outer side of the sleeve or simultaneously on both sides of the wall.

Referring to Figures 3, 4 and 5, diaphragm I is composed of threads a covered with one or several fluid-tight elastic films b forming a sleeve. Threads u and nlm b are fastened to rigid members in the form of plates A and B by any suitable means ensuring uid-tightness, for example by means of semi-circular clamps 2 and 2 screwed up by means of screws 3.

In the embodiment represented on Fig. 3, the plate B is solid whereas the plate A is provided with an orifice 8 through which any fluid under pressure can be introduced.

The fluid exerts a thrust F on each of the plates A and B which tend to be driven apart from each other. Moreover, the inner side of the diaphragm is subjected to a pressure which compels each thread to take a tension T. The resultant of all the tensions T of the threads applied to the plates A and B is on each plate a force U. These equal and opposite forces U tend to bring plates A and B nearer.

It must be pointed out that if the system left alone, the diaphragm, being originally cylindrical for instance, becomes deformed and takes through the action of the inner pressure of the fluid, the shape of a barrel which grows more and more swollen in the middle until the forces that tend to draw plates A and B apart from each other balance the forces which tend to bring them nearer. At this moment the system is in equilibrium and F:U.

It should be further noticed that if at the beginning of its deformation the diaphragm is cylinder-shaped and made up of supple yet practically inextensible threads (placed along a generating line or a helix with a constant pitch), the forces U which tend to bring the plates A and B nearer are always greater than the forces F which tend to drive them apart. Consequently, plate B will draw nearer to plate A and during this displacement will be able to exert a certain amount of work and a force whose value reaches its maximum at the beginning of the deformation process.

It should be noticed that this force is limited only by the breaking of the threads and that, by increasing the number of the threads it is always possible to increase the force without altering the inner pressure of the fluid. If, for instance, the plate A is fastened to the frame of a machine 5, the plate B tted with a rod 1 will be able to exert a pull on this rod and to cause -a certain displacement of this rod. This result can be used for producing any motion or effort.

In the example of mounting shown on Fig. e, the diaphragm I consisting of the threads a and the film b is fastened, as explained before, to the plates A and B and put inside a vessel to which the plate A is fixed. This vessel 5 receives through the orice 9 a uid under pressure which acts on the outer side of the diaphragm I which becomes deformed through a reduction of its dameter in its central part. Plate B is drawn nearer to plate A, which causes the displacement of a rod 'I fastened to plate B and sliding through the orifice 8 of plate A.

It should be noticed that the deformations of the diaphragm can take place even if the threads or cables are nearly inextensible. Only the fluidtight, elastic lms connecting the threads together undergo a lengthening or a contraction.

It should also be noticed that if the original shape of the diaphragm is not cylindrical, it is possible to produce in the case of the device shown in Fig. 3, an actiontending to drive the plates A third construction resulting from the combination of the embodiments of the diaphragms represented on Figs. 3 and 4. In this third embodiment there are two concentric diaphragms i and I which are fastened by any means whatever to the plates A and B (e. g. by such clamps as 2 and 2') provided with xing rings A and B. The plate A has an orifice 8 communicating with the duct S' through which a uid under pressure can be introduced between the diaphragms I and I'.

It can be seen how the clamps 2 and 2 can be adjusted, since they are locked by the screws 3 and 3 fixing the diaphragms I and I' to the flanges A' and B of the plates A and B.

The working of the apparatus represented in Figs. 6 and 7 is as follows: under the action of a fluid under pressure introduced between the diaphragms, the threads of these diaphragms are tightened and if the sleeves of these diaphragms were originally cylindrical, the deformation of the diaphragms would cause the plates A and B to come closer to each other. The diameter of the outer diaphragm I grows wider in the middle while the'diameter of the diaphragm i becomes smaller in the central part.

Figures 3, 9, 10, l1 and l2 clearly show how this diaphragm can -be made up of networks of threads linked together and covered with an elastic, fluid-tight wall or lm.

The shapes thus obtained Ican be of any kind or of revolution and in this case the meridian profile can be of any kind, but it is convenient to lay the networks of threads on a cylindrical surface of revolution as it is simpler to make.

Figures 8 and 9 show, for clearness sake, only three of the threads a of the network forming t'he surface s. If the surfaces s are cylinders of revolution with an axis XX', in the case of Figure 8 the threads a are rectilinear and in the case of Figure 9 the threads a are helixes with a constant pitch. If there are several nets of helically wound threads, it is advantageous to give these helixes opposite pitches: some arev right-pitched, others left-pitched. Several sets x of threads can be laid in a concentric manner.

' desired according to the force to which the diaphragm is to be subjected.

The threads or cables of the diaphragm can be made of any substance, for example, cotton, rayon, asbestos or steel. The latter substance is particularly useful when it is desired to build smallV sized diaphragms capable of transmitting relatively high forces or when it is desired to use a substance having a small elongation. The film ensuring fluid-tightness and a connection between the threads can be made of any elastic .the threads of the; diaphragm As an'example, a networlr'of threads t hasbeen represented whose ends are turneddown, like hooks, around the rings t and t which can be metallic or made oiany substance. The fluid.- tight and elastic sheets b and b ensure fluid.- tightness and can be turned down with the threads around the rings tand t.

6 Figure I6 representstwo other modes. of hiring thediaphragm..y The rings and B. can .be bonded tofrthe-:wallfof thev ends ofthe diaphragm- This adherenceito'. a metallic ring can bev directly achieved. during; vulcanisation, in the case of a rubber diaphragm.` The other mode oi fastening consistsin:` Wideningout the end of theV elastic diaphragm and`in pressing it against the ring A byz meansof. a washer r locked by the nut c screwed. on ring A (0r B). v

f The diaphragm of the present invention, `can beused to replace any diaphragm Whatever or In'the case of Fig. 1l the consruction with hooking rings t and t' is exactly the same,` but the threads and elastic sheets. are so. arranged as toclose up one of the ends. In this case', the diaphragm is inthe shape of a sack. The sack.- shaped disposition can be :worked outwithor without the rings t and, t' embedded inthe elastic mass, the rings being replaced by inner or outer framings..

In certain applications and also with aview to reducing the oost of these diaphragme, they can be made without the threadsjabeing con'- nected with such rings as t and t.- Such a construction is represented in Figs. S and 9. In this case, the diaphragm is a part of a cylinder of revolution which is obtained by rolling for" in-Y stance a sheet of threads covered with rubber sheets'or with any vother elastic substance around a cylinder serving as a support during they makingof the diaphragm. i

Figures 13 and 14 clearly show, as an example, how these diaphragme can threads are to takethe shape oi a cylindrical helix. For that purpose, there should be rolled around a metall-ic tube d of an appropriate diameter a parallelogram-shaped piece ci fabric g made upv of a set oi threads or cables @laid side by side and covered on both sides rwith a sheet of elastic substance, for example,rubber.v endfof the rolling the two opposite edges of the fabric butt against each other Without overlap'- ping, the edges of the guni-sheetsean havea. joint t in thin gum ensuring sealing.

This cylindrical tube d can serve as a support to the diaphragm during the vulcanisation if the sheets of elastic substance covering the threads are of. rubber. I Inthe case of the threads being 5.,;

laid along a generating line of the cylinder d, the fabric g is in theshape of a rectangle..

The rising of the .diaphragm to the .end .plates can be ensured by means of clamps inseveral or split clampsinone part. vIt'canalso parts be ensured, as is shown `on Fig'.v i5in` the case of being .hooked to rings t and t', either by means of a. ciampi 2 which compels the fabric to take ythe shape ot a circularv groove e of the ring A .;orby rneansof a ring h fastened to the flange B by bolts h;

The ring -lt holds the enlarged end of the diaphragm by. pressing on the bicon-ical ring .hf split in several pieces. These modes of fixing the diaphragm to the rings A and B can be used even ,if the ends of the threads are not fastened to such rings asv t and t.

All the devices known and used in engineering to fasten the lends of a Flexible pipe to parts of -machinerycan be applied with a view'to' fasteningthe ends of the-diaphragme to the rings A'and B; for example, .by meansoi metallicstrips with .tighteners, by means-oil split" metallic' clamps .forcingthe diaphragm into aggrooveaiter vit has been; putiin place,-.and. others. f

be built when the' At the Figure l? showsv in a section along the axis of revolution. of. theY diaphragm, how they rotation ofalever I0 about its axis II can b e performed. For that purpose, the plate A. fixed. to one end of the. diaphragm I is. pivotally mounted on the frame 5 by means ofthe pin. I2. The other end isl fixed to the platev B to which the end of the leverl I0 is pivoted at I3. A helical spring Ill bears on the'platesv A and. B which are kept in alignment by their telesc'oping parts 'I and I in the form of rectilinear, hollow rods. The fluid under pressure is introduced through the orifices 8,A 8 and. 8". The size and shape of the diaphragm can. be selected in such a Waythat when the pressure of the fluid increases, the lever Ill/turnsv forinstance. in the direction of the arrow EI. When thepressure decreases, the spring pushes back -thelever I0l in the direction of the arrow F2. In other words, it is possible to give theglever' I Il a reciprocating motion.

VFigures 18 and 21 showA how it is possible to produce the opening. or'the shutting of a valve I5 relative toits conical seat I5'. In the case of Eig. 18v aguided rod. 1 is. fastened at one. end to the valve I5, and at the other end. to the plate B, which plate, in its turn, is fixed to the diaphragm Thev plateA which is. fixed to the .other end oi the vdiaphragm is fastened to the support 5 by'meansofsti'ff 1ro-dst. A helicalspring Ie rests onthe: platesLA. and B. When the pressure oi the huid'. introduced through they 'orice/B of the plater A, increases, thev plate B comes nearer to Ayandlifts the'valvev I5. If the pressure of the duid vdecreases'thevalve tends to` close and when the r effective pressure of the. 'uidis zero the spaceY comprised between the two diaphragms i and I (by introducing a fluid under pressure through the orifice 8) causes the compression of thesp'ring andthe openingof the valve I5 thus 1 'creating' a connection between the openings i6 and I'I ofthe valve.y

Figure 19'jrepresent's the diaphragms I and I", thefrod 1," and-the'spring I4 in a section along a plane at right angles to the axis XX" of the rod 1. On Fig. 'a section similar -to that of Fig. 19 shows the diaphragms I when they are not concentric but arranged side by side, on the plate B and on parallel lines. These diaphragms can be arranged so that the increase of pressure causes the valve to shut rather than to open.

This diaphragm enables the valve or the movable element of a valve of any diameter to be remotely controlled by means of a small valve controlling the admission and the discharge ofthe fluid acting on the diaphragm.

The application of this diaphragm is particularly useful to replace the plane, conical or domeshaped diaphragms which are commonly used on certain valves.

It should be noticed that the action of this diaphragm is all the more sensitive and effective as its shape approaches that of a cylinder of revolution. This property can be utilized when it is desired to control automatically the expansion of the discharge of any fluid 'through a valve., the diaphragm serving as a driving member for controlling this expansion.

When it is desired to obtain a large displacement with these diaphragms without greatly varying the diameter of the latter Vit is possible to place a series of them end to end, separating them with rings xing the extremities of two adjacent diaphragms. The displacement of the last ring equals the sum of the displacement of all the rings.

Lastly this diaphragm can be used in pumps to replace plane or dome-shaped diaphragms, or to replace pistons.

It can also be used in place of a spring, the stiffness of which can be adjusted at will and from a distance by altering the pressure of the actuating uid.

Finally, the stretching of the central part or the diaphragm can be utilised to apply this central part against one or several orifices Vwhich can be closed by the wall of the diaphragm, In such cases the diaphragm is then directly used as a valve member.

What I claim is:

l. A device for producing displacements through pressure-variations in a fluid, comprising a nxed rigid member, a second rigid member movable with respect to said'iixed member, iiexl ible, substantially inextensible thread-likeelements and an elastic fluid-tight sleeve-like enclosure extending lengthwise of, and surrounding the thread-like elements in juxtaposed concentric relationship, said thread-like elementsbeing connected throughout their length with said sleeve-like enclosure, the `respective ends of said thread-like elements and said sleeve-like enclosure being stretched between, and attached to said respective rigid members, one of said rigid members having a duct communicating with the interior of the enclosure for Varying the pressure of fluid therein, whereby said movable member will be displaced as a result of the variations in effective length of said thread-like elements due to the flexure thereof in response to pressure variations in the fluid Within said enclosure.

2. A pressure-responsive device comprising a fixed rigid member, a second rigid member movable with respect to said xed member, flexible, substantially inextensible thread-like elements, an elastic fluid-tight sleeve-like enclosure extending lengthwise of and surrounding the thread-like elements in juxtaposed concentric relationship, said thread-like elements being connected throughout their lengthwith said sleevelike enclosure,A the respective ends of said elements and said enclosure being stretched between and attached to said respective rigid members, said iixed member having intake means therein for delivering pressure-fluid into said enclosure, whereby the movable member will move in response to variations in the eifective length of said elements resulting from flexure thereof in response to pressure-variations in the fluid in said enclosure.

3. A pressure-responsive device of the type described comprising a fixed rigid member, a second rigid member movable with respect to said fixed member, flexible, substantially inextensible thread-like elements, an elastic sleeve-like means extending longitudinally of said elements and surrounding the thread-like elements in closely juxtaposed concentric relationship therewith, said thread-like elements being connected throughout their length with said sleeve-like means, the respective ends of said elements and said means being stretched between and attached to said rigid members, said fixed member hav- .ing an orice communicating with the interior of said sleeve-like means and a vessel surrounding the sleeve-like means and provided with a pressure-fluid orifice for varying the pressure Within said vessel about the exterior of said elastic sleeve-like means, whereby said movable member will move in response to variations in the effective length of said threads as a result of their flexing in response to pressure variations in the fluid on the exterior of the sleeve-like means.

4. A pressure-responsive device comprising a nxed rigid member, a second rigid member movable with respect to said fixed member, two coaxial structures each comprising flexible, substantially inextensible thread-like elements and an elastic fluid-tight sleeve longitudinally coextensive and contiguous therewith, said thread- Vlike elements being connected throughout their length with said sleeve, the respective ends of said threads and of said related sleeve being stretched between and attached to said rigid members, said Xed member having a pressureiiuid intake into the space deiined between said sleeves, whereby said movable member will move 1n response to the flexure-variations in said ihrads as a result of pressure-variations in said 5, A'pressure-responsive device comprising a fixed rlgid member, a second rigid member movable With respect to said xed member, iiexible, substantially inextensible threads arranged along Vthe generatrices of a cylindrical surface and an elastic cylindrical sleeve contiguously coextensive and concentric with f said threads, said thread-like elements being connected throughout their length with said sleeve, the respective ends of said threads and said sleeve being stretched betweenv and attachedy to said rigid members, said fixed member having a pressureiiuid inlet into the interior of said sleeve whereby the movable member Will move in response to variations in the effective length of said threads resulting from iiexure-variations in response to pressure-variations in said fluid.

6. Apressure-responsive device comprising a xed r1g1d member, a second rigid member movable with respect to said fixed member flexible substantially inextensible helically-extending thread-like elements and a cylindrical-elastic sleeve contiguously coextensive with and'concentrically surrounding said threads, said threadlike elements being connected throughout their length with said sleeve, the respective ends of` said threads and saidv sleeve being stretched loetween and attached to said rigid members, said xed member having a pressure-fluid inlet into the interior of said sleeve whereby the movable member Will move in response to variations in effective length of said threads resulting kfrom exure variations therein in response to pressure variations in said iiuid.

ALEXANDRE HENRI MORIN.

References Cited in the le of this patent UNITED STATES PATENTS Name Date Mayall July 14, 1863 Number Number 10 Name Date Mayall Apr. 13, 186.9 Wilkins Mar. 25, 1913 Stephens July 27, 1937 Chilton Nov. 7, 1939 Meyers Aug. 4, 1942 Fausek July 13, 1943 Yerger Apr. 3, 1945 Zellos Oct. 23, 1945