FR2631416A1 - UNIDIRECTIONAL VALVE - Google Patents

Abstract

The invention relates to a one-way valve. This valve 1 comprises an inlet mouth 3, an outlet mouth 4, means 7 for intercepting a main fluid which can allow the latter to pass only from the inlet mouth 3 to the outlet mouth 4. , and a piston 28 able to move, by a pneumatic control with a pilot fluid, from a first position in which the passage between said mouths 3 and 4 is regulated by interception means 7 to a second position in which the piston 28 drives with it the interception means 7, thus determining the passage of the main fluid in one direction or the other according to the pressure values present in the outlets 3 and 4.

Description

UNIDIRECTIONAL VALVE

  The present invention relates to a one-way valve which can be used particularly in installations for the pneumatic supply of organs, especially in machines for

the Woodcraft.

  The present invention aims to provide a unidirectional valve that allows, at the end of the user's work cycle, a

  efficient and proper exhaust of the latter.

  On the basis of the present invention, there is provided a one-way valve which can be inserted along an installation and allowing the passage of a main fluid under pressure, characterized in that it comprises an inlet mouth, a mouth of outlet, means for intercepting the fluid allowing it to go from said inlet mouth to said outlet mouth and to prevent its passage in the opposite direction, and a piston to pass, as a result a pneumatic control provided by a piloting fluid under pressure, a first position in which the passage between said inlet mouth and said outlet mouth is permitted by said interception means at a second position in which said piston carries with it said interaction means determining the passage in one direction or the other between said mouths of said main fluid according to the values of

  pressure of the latter to said mouths.

  In order to allow a better understanding of the present invention, two preferred embodiments are now described, by way of non-exhaustive examples, with reference to the accompanying drawings, in which: FIGS. 1 and 2 are sections of two different modes embodiment of a unidirectional valve; and FIG. 3 is a block diagram of a pneumatic installation of a unidirectional valve made according to the

  specifications of the present invention.

  According to the illustration object of the accompanying drawings, the object of the present invention is a unidirectional valve 1 through which the pneumatic supply of a user is carried out and which therefore does not allow, during the work cycle of the user, as the passage of a fluid under pressure towards the user. In addition, this valve 1, at the end of the user's work cycle, can be driven pneumatically to achieve the ventilation of the user as will be described

  better below with reference to Figure 3.

  The valve 1 illustrated in FIG. 1 comprises a small cylinder 2 at the longitudinal ends of which are formed an inlet mouth 3 and an outlet mouth 4 for a main fluid which flows along a pneumatic installation. The small cylinder 2 is supported by a bell-shaped body 5 having laterally an inlet mouth 6 for a piloting fluid making it possible to determine, under determined conditions and more particularly at the end of the work cycle, the opening of the communication. between the mouths 3 and 4 and thus the passage of the fluid from the user to the

  part of the installation upstream of the valve 1.

  The valve 1 comprises an annular and plane element 7 made of a flexible material which, in the presence of a fluid under pressure in the inlet mouth 3, deforms and allows the passage of this fluid to the outlet mouth 4 and which , in the presence of a fluid in the outlet mouth 4 subjected to a pressure value greater than that present in the inlet mouth 3, closes the passage of this fluid to the inlet mouth 3. The fluid for piloting , that, as already mentioned, is made to act under predetermined conditions, controls the translation of the flexible element 7 so as to allow the passage of the fluid from the mouth 4 to the mouth 3 for a predetermined period of time sufficient to allow the user to purge this fluid. So, if the user is a gripping member of a body on which an automatic machine is performing machining operations, the user's exhaust allows the automatic recovery of

this body.

  The bell-shaped body 5 comprises an upper wall 8 and a cylindrical lateral wall 9 having an upper zone along which the inlet mouth 6 is formed, close to the connection with the wall 8, which consists of a sleeve 11 of which an inner portion is threaded for coupling with a conduit not shown. The small cylinder 2 has an upper portion 12, a first portion of which is external to the body 5 and a second portion of which is internal to the body 5 through a hole 13 formed in the wall 8. An annular groove for a holding ring 14 is provided on the small cylinder 2 in correspondence with the hole 13. The two pieces of the upper part 12 have different diameters and, in particular, the part outside the body 5 has a larger diameter which determines an annular shoulder 15 by which the small cylinder 2 is supported by the body 5 in correspondence with the hole 13. The inlet mouth 3 of the small cylinder 2 is formed along this upper portion 12 and is nothing more than an axial blind hole having an upper portion 16 threaded to allow coupling with a conduit and a lower portion 17 of smaller diameter. A plurality of radial holes 18 are formed in correspondence with the inner axial end of the portion 17 in the small cylinder 2. On the outer surface of the small cylinder 2, just above the outer mouth 18, is formed a base The zone of the lower part of the portion 12 in which the holes 18 are formed has a smaller diameter so as to define a chamber

annular 20.

  The small cylinder 2 has a solid central portion 21 of reduced longitudinal dimension and of diameter smaller than that of the zone mentioned just before in which the holes 18 are formed. The reduction of the diameter defines in this zone an annular shoulder 22 with which, in determined working conditions, the flexible element 7 is in sealing contact and obstructs the chamber 20 and, as it appears more clearly later, the passage between the mouths 3 and 4. The small cylinder 2 finally has a lower portion 23 having two parts, of which the lower part 7 is external to the body 5 and is threaded for coupling with a conduit, and the upper part is inside the body 5. The latter, in correspondence with the lower edge of its wall 9, is closed by a plate 24 supported by a ring 25 of the Sieger type carried by the lower part 23. The outlet mouth 4 is none other than an axial blind hole formed in the part 23 and whose inner end carries a plurality of radial holes 26. On the part 23 is formed an annular base for a ring

  holding 27 just under the outlet of the holes 26.

  The zone of the portion 23 in which the holes 26 are made has a diameter equal to that of the portion 21 and less than the remainder of the portion 23. Inside the body 5 and around the small cylinder 2 is placed a ring piston 28 being able to move axially under the action of the fluid for piloting, against the action of a spring 29 prestressed - the piston 28 has an upper portion 30 whose inner diameter is substantially equal to the outer diameter of the lower part section 12 on which this upper portion 30 comes into operation. In a working position in FIG. 1, in particular in the left part of the valve 1, the upper end of the upper part 30 of the piston 28 is substantially in contact with the inner face of the wall 8, and its lower end at the same the level of the shoulder 22. The annular chamber 20 is delimited at the top by the zone of diameter greater than that of the lower part of the part 12, at the bottom by the flexible element 7, and laterally by the zone of the part 12 which carries the holes 18 and the inner portion of the portion 30 of the piston 28. The piston 28 has a lower portion 31 of larger inside diameter than that of the portion 30 on which is therefore defined an annular shoulder 32. The portion 31 carries inside an annular body 33 whose upper end face makes the clamp against the shoulder 32 of the outer ring of the flexible element 7. The part 31 has, in particular , a lower edge folded over an annular recess in the side wall of the body 33. The latter and the flexible element 7 are thus secured to the piston 28. The inner hole of the body 33 corresponding to the portion 21 and to the portion 23 o are formed the holes 26 is flared while in correspondence with the remaining area of the portion 23, it has a diameter equal to that of the latter. From the outer surface of the portion 30 of the piston 28 extend two flat annular projections 34 and 35 parallel to each other and parallel to the plate 24. Between the projections 34 and 35 is mounted an annular seal 36 of the lip type and can be used sealing gasket on the side wall 9 of the body 5 below the outlet of the fluid for piloting. In this way, there is created inside the body 5 and around the portion 30 of the piston 28 an annular chamber 37 sealed for this fluid for control. The spring 29 is of the helical type and bears at the top in the projection 35 and at the bottom on a plate 38 parallel

  to the plate 24 and mounted inside the body 5.

  The plate 38 is part of a member that records that the spring 29 is prestressed. This member comprises a threaded tip 39 screwed onto a threaded lower portion of the wall 9 of the body 5. The end piece 39 carries in its lower part a plate 40 from which extend upwards and across the plate 24 rungs 41 on which the inner plate 38 is supported. By screwing the end piece 39 in one direction or the other along the threaded part of the wall 9, a translation upwards or downwards is effected. plate 38 and thus makes a more or less strong compression of the spring 29. The valve I is finally provided with a member by means of which can be manually controlled a downward translation of the piston 28 so as to admit a small amount of main fluid downstream of the valve 1 if it is desired to carry out only a fast and precise positioning of the components of the installation mounted downstream of the valve 1. This member comprises a pivot 42 pivotable thanks to a suitable utensil and having a t 43 is externally laterally to the body 5 and a shank 44 extending through a hole in the wall 9 into the annular chamber 37. The shank 44 is suitably profiled and substantially in contact with the upper face of the annular chamber 37. The shank 44 is the projection 34, so as to determine by means of the rotation of the

  pivot 42 downward translation of the piston 28.

  The operation of the valve 1 illustrated in FIG. 1 is as follows: the main fluid enters, through the mouth 3 and the holes 18, into the annular chamber 20. From there, the fluid deforming the flexible element downwards 7 manages to flow towards the part of the inner hole of the body 33 and from there through the holes 26 to the outlet mouth 4, as illustrated by the hatching in the left part of FIG. 1. By interrupting the flow of the main fluid from the mouth 3 to the mouth 4, the annular chamber 20 is sealed by the flexible element

  7 which returns to bear on the shoulder 22.

  Therefore, if at this moment the pressure value of the fluid inside the user, and therefore at the outlet mouth 4, is greater than that represented by the possible fluid present upstream of the valve 1 and therefore at the inlet mouth 3, the passage between the mouths 3 and 4 is obstructed and therefore, if the user is a gripping member without any possibility of escape, it does not release yet the body on which the machine is in the process of perform machining. This body is released by the admission, through the mouth 6, of a pilot fluid in the chamber 37. This fluid determines, against the action of the spring 29, the downward translation of the piston 28, as illustrated in FIG. right part of the valve I of fig. 1. This piston drives behind the body 33 and the flexible element 7 and thus this translation determines the pneumatic communication between the mouths 4 and 3. In this way, the fluid present in the user can be conveyed upstream of the valve 1 and the user releases the body mentioned above. The pneumatic control made with the piloting fluid normally has a very short duration because the purging of the fluid of the user is generally carried out in a very short time. Naturally, the interruption of the pneumatic control causes the spring 29 to return the piston 28 to its initial position. The valve 1 illustrated in FIG. 2 differs from that described with reference to FIG. 1, since it is not provided with the recording member of the spring 29 and with the manual control member for the passage of small quantities of fluid. and because the closure member of the chamber 20 is defined by a plane annular element 51 preferably made of a rigid material for sealing the annular chamber 20 when a coil spring 52 prestressed press this element 51 on the shoulder 32 and 22. The spring 52 is carried by the body 33 which, in this case, is structured differently from the analogous body described with reference to FIG. 1. Indeed, the body 33 has on its upper face an annular base 53 on which bears the lower end of the spring 52. From this face coaxially extends upwards an annular appendage 54

  which bears directly on the shoulder 32.

  The operation of the valve 1 illustrated in FIG. 2 is substantially similar to that described for the valve 1 with reference to FIG. 1. In this case, the main fluid against the action of the spring 52 determines the downward translation of the element 51 thus realizing the pneumatic communication between the mouths 3 and 4. In the absence of fluid under pressure at the mouth 3 or in the presence of a fluid subjected to a pressure value lower than that of the fluid present at the mouth 4, the spring 52 causes the translation against the shoulders 32 and 22 of the element 51 and therefore, the interruption of the pneumatic communication between the mouths 4 and 3. In this valve 1 also, the piston 28 carries with it the body 33 and the element 51 during its translation following a pneumatic control by

  via the piloting fluid.

  Fig. 3 schematically illustrates an installation along which is mounted the valve 1. This installation comprises a source of pressurized fluid constituted for example by a compressor 61 connected via a solenoid valve 62 to the inlet mouth 3 of the valve 1. The compressor 61 is further connected via a second solenoid valve 63 to the mouth 6 of the valve 1. The actuation of the solenoid valves 62 and 63 is controlled by members 64 and 65 respectively, constituted for example by an automatic electric switch or manually operated. The outlet mouth 4 of the valve 1 is then connected to a user 66. This simple installation with a reduced amount of components has been described by way of example only, and only the essential components have been described, which naturally can to be of a different type from those illustrated. The installation illustrated in fig. 3 operates as follows: Normally, in a machine performing machining on a body, it must, during these machining, be maintained in a specific position. To achieve this blocking, it is possible to use gripping members (user

  66) of the pneumatic type already known on the market.

  For example, by manually actuating the member 64 is controlled the solenoid valve 62 or a similar device to allow the passage of a fluid under pressure to the gripping member. The valve 1 allows this pneumatic communication and prevents a possible passage in the opposite direction, and therefore, when the gripping member has achieved its purpose of blocking the body, it is possible to interrupt the flow of fluid under pressure between the source (compressor 61) and the valve 1. This is possible either by actuating the member 64 or by applying a suitable sensor to identify the correct execution of the blockage of the body. At the end of the work cycle of the machine, it is necessary to release the body and therefore it is necessary to obtain a purge of the liquid under pressure in the gripping member. For the body to be released, it is necessary to allow, through the mouth 6, the admission of a pilot fluid in the valve I so that a pneumatic communication is determined between the mouths 4 and 3 of this valve, as previously described. The piloting fluid, in the case illustrated, is of the same type as the main fluid, the mouth 6 being connected to the same power source as the gripping member. Naturally, the piloting fluid can be different and therefore come from a different source. The passage of the piloting fluid is effected by actuating for a sufficient duration the solenoid valve 63 or. a similar device, via the member 65 which can be in turn manually actuated by a sensor for raising -20 the end of the machining cycle, by an electrical distributor control and adjustment of the machine , or by a movable member, for example an operative member of the machine which, at the end of the cycle, returning to its rest position, acts

on the organ 65.

  The description above highlights

  clearly the benefits achieved through the

  embodiment of the present invention.

  In particular, it has been realized a unidirectional valve which determines the admission of a fluid under pressure in the user without the need for piloting. The use of a unidirectional valve increases the level of safety of use because following a pressure drop upstream of the valve, it automatically obstructs the passage of the fluid of the user upstream . The installation along which is mounted the valve object of the present invention is safer and simpler, since it manages the release of the user. In addition, it should be noted that this valve can be used also as a two-way valve whose operation is identical to that described above for the passage of the fluid from the mouth 3 to the mouth 4 and which will allow the constant admission of the fluid into the chamber 37 for the passage of fluid from the mouth 4 to the mouth 3. The valve may be provided with a manual actuating member of the piston 28 and a recording member of the spring 29. Finally, it should be noted that the valve described here is compact, of simple construction and that it allows the rotation of the body 5 around the small cylinder 2 so as to guide the mouth 6 and thus, to facilitate the assembly of the latter itself

  in hard to reach places.

  Finally, it is clear that modifications and changes can be made to the valve 1 described and illustrated here without going out

  of the purpose of the claims of this

invention.

  In particular, the body 5 may be made of metal or plastic such as Teflon. In addition, the mouths 3, 4 and 6 can be of the female type thus threaded, or of the male type thus threaded. It is possible to provide the mounting of the solenoid valve 63 or a similar device directly in the mouth 6. Finally, the applications of the valve 1 may be different from those shown and the installation along which is mounted the valve 1 can

  be different from that illustrated in fig. 3.

Claims (15)

  1. Unidirectional valve that can be inserted along an installation and that can allow the passage of a main fluid under pressure, characterized in that it comprises an inlet mouth (3), an outlet mouth (4) means (7 or 51) for intercepting the fluid that can allow the passage of the fluid from said inlet mouth (3) to said outlet mouth (4) and can prevent its passage in the opposite direction, and a piston (28) movable, as a result of pneumatic control via a piloting fluid under pressure, between a first position in which the passage between said inlet mouth (3) and said outlet mouth (4) is permitted through said interception means (7 or 51) and a second position in which said piston (28) carries with it said interception means (7 or 51), thus determining the passage through a direction or in the other between said mouths (3 and 4) of said fluid the principal according to pressure values to which the latter is subjected in said mouths (3 and 4).   2. Unidirectional valve according to claim 1, characterized in that it comprises a first substantially cylindrical body (2) with opposite axial ends of which are formed said mouths (3 and 4), said piston (28) being annular and mounted along said first body (2) and defining therewith a first annular chamber (20) in pneumatic communication with said inlet mouth (3) and said interception means (7 or 51) being carried by said piston. (28) and capable of obstructing the passage between said first annular chamber (20) and said outlet mouth   (4) during the first position of said piston (28).   3. Unidirectional valve according to claim 2, characterized in that said first body (2) has a first portion (12) in which is formed a blind axial hole whose upper end constitutes said inlet mouth (3) and the lower end is in communication, via at least one radial hole (18) with said first annular chamber (20), and a second portion (23) in which is formed a second blind axial hole of which lower end constitutes said outlet mouth (4) and at the upper end of which begins at least one radial hole (26) which opens below said interception means (7 or 51) which obstruct below said first annular chamber ( 20) and bearing against a shoulder (22) formed between said portions (12 and 23) of said first body (2) and a shoulder (32) provided at inside said piston (28).   4. Unidirectional valve according to claim 3, characterized in that said piston (28) has an upper portion (30) which, during the first position, corresponds to a lower section of said upper portion (12) of said first body (2) and a lower portion (31) having an inner diameter greater than said upper portion (30) of said piston (28) and which, during said first position thereof, corresponds to an upper section of said lower portion (23) of said first body (2), a tubular sleeve (33) able to press said interception means (7 or 51) against said shoulder (32) of said piston (28) being internally secured to   said lower portion (31) of said piston (28).   5. Unidirectional valve according to at least one of the   Claims 2 to 4, characterized in that it comprises   a second bell-shaped body (5) in which said piston (28) is located, having an inlet mouth (6) for the piloting fluid, and inside which is defined a second annular chamber (37); ) sealed for mounting on an annular projection (35) of said   piston (28) of an annular seal (36).   6. Unidirectional valve according to claim 5, characterized in that said second body (5) can rotate about its axis so as to make possible   the orientation of its inlet mouth (6).   7. One-way valve according to one of   Claims 4 to 6, characterized in that   second body (5) comprises a closure plate (24) supported by said lower part (23) of said first body (2), spring means being mounted between said plate (24) and said projection (35) allowing to oppose the translation of said piston (28) between first and second position.   8. One-way valve according to at least one of the   Claims 2 to 7, characterized in that   interception means comprise a flat annular element (7) made of a flexible material and having an outer annular segment secured to said piston (28). 9. One-way valve according to one of   claims 4 and 8, characterized in that said   outer annular segment of said flexible material member (7) is clamped between the upper ends of said tubular sleeve (33) and said shoulder (32) of said piston (28), the inner annular segment of said flexible material member (7) being in contact for pneumatically sealing said first chamber (20) with said shoulder (22) of said first body (2) during the first position of said piston (28) and deflectable thereby to open said chamber (20) thereby thus leaving free passage of the main fluid between said mouths (3 and 4) of said first body (2), when the pressure value at said inlet mouth (3) of said first body (2) is greater than that of said outlet mouth (4).   10. One-way valve according to at least one of the   Claims 2 to 8, characterized in that   interception means comprise a flat annular element (51) made of a substantially rigid material and making it possible, by means of spring means (52), to effect the obstruction of the passage of the main fluid between said mouths (3 and 4) of said first body (2) during the first position of said piston (28) and in the absence of pressure in said inlet mouth (3) of said first body (2) or in the presence thereof in a pressure value less than that present in said outlet mouth (4), said main fluid being able, in the presence, in said inlet mouth (3) of said first body (2) to have a pressure value greater than that in said outlet mouth (4 ) against the action of said second spring means (52), translating said flat annular element (51) thus leaving free the passage from said inlet mouth (3) to said outlet mouth (4) of said first body (2).   11. One-way valve according to one of   claims 4 and 10, characterized in that said   flat annular element (51) bears against said shoulder (22 and 23) of said first body (2) and said piston (28), said second spring means (52) being   carried by said tubular sleeve (33).   12. A one-way valve according to claim 7, characterized in that it comprises a device for recording the calibration of said first spring means (29) having a tip (39) screwable along a threaded portion d a side wall (9) of said second body (5), said end piece (39) carrying a plate (40) able to act, by means of a plurality of steps (41), on a ring (38) inside said second body (5) and on which support said first spring means (29).   13. A one-way valve according to one of claims 7 and 12, characterized in that it comprises a pivot (42) whose profiled portion (44) is internal to said second body (5) and can during manual rotation said pivot (42), determining the translation, against the action of said first spring means (29), of said piston (28) from the first position to an intermediate position relative to the second position.   14. Pneumatic installation according to at least one   of the preceding claims, characterized in that   comprises: a source (41) of a main fluid under pressure; a unidirectional valve (1) mounted between said source (61) and a user (66) and comprising interception means (7 or 51) capable of effecting the passage of the main fluid from said source (61) to said user (66) and may obstruct the passage in the opposite direction; a first interception member (62) mounted between said source (61) and said valve (1) and actuated by a first controller (64); and a second interception member (63) actuated by a second control member (65) and mounted between a second source (61) of a driving fluid capable of moving a piston (28) of said valve (1). ) a first position in which the passage of the main fluid is permitted by said intercepting means (7 or 51) from said first source (61) to said user at a second position in which said piston (28) carries with it said interception means (7 or 51) determining the passage of the main fluid in one direction or the other depending on the pressure values present immediately upstream and downstream of said valve (1).   15. Pneumatic installation according to claim 14, characterized in that said interception members   respectively comprise solenoid valves (62 and 63).