US3326234A

US3326234A - Fluid conductor and take-off apparatus

Info

Publication number: US3326234A
Application number: US341289A
Authority: US
Inventors: John J Baker; William G Benjey
Original assignee: Gardner Denver Inc
Current assignee: Gardner Denver Inc
Priority date: 1964-01-30
Filing date: 1964-01-30
Publication date: 1967-06-20
Anticipated expiration: 1984-06-20

Description

June 20, 1967 BAKER ETAL FLUID CONDUCTOR AND TAKE-OFF APPARATUS 4 Sheets-Sheet 1 Filed Jan. 30, 1964 FIG.|

INVENTORS Jqh n J.GB0Bker WIIImm en ey ym My fiJ/W June 20, 1967 J BAKER ET AL 3,326,234

FLUID CONDUCTOR AND TAKE-OFF APPARATUS Filed Jan. 30, 1964 4 Sheets-Sheet 2 23 5o 3 2 50 z 1 |2 5 4 J V, 2 I3 VI 49 'k\ r 8 26 8 g H 4 John J. Baker BY William G. Benjey June 20, 1967 j J BAKER ET AL FLUID CONDUCTOR AND TAKE-OFF APPARATUS 4 Sheets-Sheet Filed Jan. 50, 1964 INVENTORS John J. Baker BY Wilhom G. Benjey 054/1444, 6M, MM

June 20, 1967 J. J. BAKER ET AL FLUID CONDUCTOR AND mxvow APPARATUS 4 Sheets-Sheet 4 Filed Jan. 30, 1964 FIG. 5

INVENTORS Jqhp J. Baker BY W|ll|om G. Benjey United States Patent 3,326,234 FLUID CONDUCTOR AND TAKE-OFF APPARATUS John J. Baker and William G. Benjey, Alpena, Mich., as-

signors to Gardner-Denver Company, Quincy, 111., a

corporation of Delaware Filed Jan. 30, 1964, Ser. No. 341,289 27 Claims. (Cl. 137580) This invention relates to fluid conductor and take-oil apparatus of the kind adapted to deliver pressure fluid to fluid operated tools or the like and more particularly the invention pertains to an improved pressure fluid conduit and take-off apparatus therefor which is capable of tapping the conduit at any point along the length of the latter.

The embodiments of the invention herein disclosed are improvements over the constructions disclosed in our earlier Patents Nos. 2,798,506 and 3,012,574, to which reference may be had for some of the details of the constructions hereinafter briefly described.

An object of this invention is to provide an improved fluid conduit or conductor which is more economical to produce than are previously known conductors used for similar purposes.

Another object of the invention is provide a ported fluid conductor having improved sealing characteristics over previously known analogous conductors, but being as readily tappable at any selected point along its length.

A further object of the invention is to provide a fluid conductor and take-01f member which cooperate with one another to assure tapping of the conductor in such manner as to preclude any leakage of fluid past the take-off member.

Another object of the invention is to provide a ported fluid conductor and takeoff member of the character referred to equipped with cooperating means for assuring registration of the fluid passages in the take-off member with the ports in the conductor.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, in which:

FIGURE 1 is a fragmentary view partly in side elevation and partly in section of fluid conducting and take-off apparatus constructed in accordance with one embodiment of the invention;

FIGURE 2 is an enlarged, vertical sectional view taken on the line 22 of FIGURE 1;

FIGURE 3 is an enlarged, vertical sectional view through the fluid conductor and taken on the line 3-3 of FIGURE 1;

FIGURE 4 is a top plan view of a deformable wall forming part of the fluid conductor and illustrating a part of the wall deformed;

FIGURE 5 is a view similar to FIGURE 1, but illustrating a modified form of fluid conductor; and

FIGURE 6 is a sectional view taken on the line 66 of FIGURE 5.

A fluid conductor constructed in accordance with the embodiment of the invention disclosed in FIGURES 14 comprises an elongated, metal, generally U-shaped housing or body 1 having a pair of generally

parallel side walls

2 and 3 that are joined together at corresponding ends by a transverse wall 4. Secured to and extending beyond the wall 4 is a pair of generally L-

shaped legs

5 and 6 terminating in spaced apart, confronting flanges 7 which may support the housing 1 on an inverted T rail (not shown). Each of the inner surfaces of

Walls

2 and 3 is provided with a laterally projecting, downwardly inclined ICQ rib 8 which is longitudinally grooved to form a pocket or recess 9 terminating adjacent the open side of the housing in a lip 10. Each

wall

2 and 3 also is provided with an external, laterally extending rail 11 for a purpose presently to be explained. The housing 1 is closed at its opposite ends by suitable walls (not shown).

The open side of the housing I normally is closed by a deformable wall member 12 .formed of a resilient, flexible substance such as rubber or rubber-like material. The member 12 is coextensive in length with the housing 1 and has a relatively thick flexible center strip or section 13. From each side of the section 13 extends a relatively thin strip or section 14 terminating at its free edge in an enlargement comprising a generally cylindrical head 15 and an integral rib 15a. Inasmuch as the sections 14 are thinner than the central section 13 of the member 12, the sections 14 are more flexible than the central section. The overall width of the member 12 is such as to enable the beads and

ribs

15, 15a to be received in the respective grooves 9 with little, if any, distortion of the sections 14.

Clamping means 16 is provided for removably retaining each of the side edges of the member 12 in its associated groove and comprises a pair of generally channelshaped members 17 each of which has a web 18 terminating at one end in a flange 19 that is adapted to engage a shoulder 20 formed on the

adjacent wall

2 or 3. The other end of the web 18 terminates in a leg 21 having an enlarged head 22 which seats on the lip 10 of the associated housing wall and locks the adjacent bead 15 and rib 15a in the associated pocket 9 so as to preclude inadvertent separation of the wall member 12 from the housing 1. The confronting surfaces of the heads 22 converge toward one another in a direction outwardly of the housing but are spaced apart from one another to permit engagement of the wall 12 by a take-off device yet to be described.

When the wall member 12 is secured to the housing in the manner disclosed, the interior of the housing comprises a closed chamber 23 in which pressure fluid such as air may be maintained under pressure. Fluid may be introduced to the chamber through a suitable fitting such as is disclosed in Patent No. 2,798,506.

Except in the region where the wall 12 is engaged by a take-off device, the wall assumes the position indicated in FIGURE 3. The pressure of fluid in the chamber 23 tends to force the wall 12 outwardly of the housing so as to maintain the central portion 13 of the wall in snug engagement between and against the heads 22 of the clamping means 16 and the outer sides of the wall section 13 taper or converge toward one another complementally to the adjacent surfaces of the heads 22 so that the pressure of the fluid in the chamber wedges the wall against the clamping heads 22. The tapering sides of the wall section 13 cooperate with the beads and

ribs

15, 15a to prevent dislacement of the wall 12 from the housing, and the beads and ribs seal the open side of the housing to prevent the escape of fluid between the member 12 and the housing. Both the outer and inner surfaces of the central part 13 of the wall 12 are flat, as is best shown in FIGURE 3.

Extending inwardly from the outer surface of the Wall section 13 is a plurality of longitudinally spaced ports or bores 25 that are open externally, but which terminate short of the chamber 23. The section 13 of the deformable wall is provided with a plurality of slits 26 each of which extends from the inner surface of the wall section 13 toward the outer surface thereof, and the slits are so located with respect to the ports 25 that each slit communicates with a port. Each slit is of such depth as to intersect the adjacent bore, but terminates short of the exposed or outer face of the center section. The wall portions on opposite sides of each slit normally abut each 3 other to seal the slits and prevent loss of fluid through the ports 25. As is indicated in FIGURE 4, the slits 26 extend obliquely to the longitudinal axis of the central section 13, and each slit preferably is formed at substantially 45 to the longitudinal axis of the wall.

The fluid take-off apparatus or wheel is designated generally by the reference character 27 and comprises a disk 28 on which is fixed an annulus 29 having a flat peripheral edge of such width as to fit between the heads 22 of the clamping members 16. The disk 28 is fixed on a shaft 30 having a number of radially extending fluid passages 31 therein which communicate with an axially extending passage 32. The disk 28 has an annular passage 33 surrounding the shaft 30 and which communicates with a number of radially extending passages 34. Each of the passages 34 communicates with an annular recess 35 formed in the annulus 29 and which terminates short of the peripheral edge thereof. Communicating with the recess 35 is a plurality of substantially radially extending ports 36 uniformly spaced about the periphery of the annulus 29, the spacing between adjacent ports 36 corresponding to the spacing between adjacent ports 25 in the wall 12. Fitted in each of the ports 36 is a tubular sleeve 37 terminating at its radially outer end in a substantially spherical bead 38 of greater diameter than the diameter of the ports 25 so as partially to be received in one of the ports 25 in snug engagement with its side Walls. Inwardly of the ports 36 is a sealing ring 39 which normally seats against the radially inner ends of the sleeves 37 to seal the passages therein.

The axially extending passage 32 in the shaft 30 communicates with radial passages 41 provided in one end of the shaft. The passages 41 are enclosed by a fitting 42 that is rockably mounted on the shaft. Within the fitting 42 is an annular chamber 43 in communication with whichis an interiorly threaded opening 44 to which one end of a hose (not shown) may be attached. The other end of the hose may be attached to a pressure fluid operated tool such as a pneumatic wrench that is equipped with a valve operable'selectively to enable and disable the fiow of pressure fluid through the opening 44.

Means is provided for mounting the take-off device 27 in operative association with the fluid conductor and comprises at each side of the disk 28 a hanger member 45 having a pair of arms 46 which diverge from a hub 47 that rotatably journals the shaft 30 by means of bearings 48. The free end of each arm 46 supports a stub shaft 49 on which is journaled a roller 50 that rides upon the adjacent track 11 so as to suspend the take-off apparatus 27 beneath the deformable wall 12 and in condition for movement longitudinally of the housing 1.

The length of the hanger arms 46 is so related to the diameter of the fluid take-off device 27 that, in assembled relation, the distance between the flat, outer surface of the wall section 13 and the axis of rotation of the disk 28 is less than the radius of the fluid take-ofl device. Consequently, the peripheral edge of the annulus 29 will engage a portion of the wall section 13 and deform the wall into the chamber 23 along an are having a curvature corresponding to the curvature of the annulus 29, the deformation of the wall section 13 being permitted by the flexibility of the material from which the

Wall sections

13 and 14 is made.

The region of maximum deformation of the wall 12 by the take-ofl? device will be at a point which is tangent to the peripheral edge of the annulus 29 at the vertical center line of the latter. From this point in either direction longitudinally of the fluid conductor, the inward deformation of the wall 12 will diminish. In the region of maximum deformation of the wall 12, those portions of the latter adjacent the slits 26 will be spread apart (see FIG- URES 1 and 4) so as to permit the egress of fluid from the housing 1 through the spread apart slits, their communicating ports 25, and the passages in the sleeves 37. The slight oversize of the beads 38 relative to the diameter of the ports 25 prevents any leakage of fluid between the wall 12 and the periphery of the take-off device. Fluid thus delivered to the sleeves from the interior of the housing 1 will displace the sealing ring 39, as is indicated in FIGURES 1 and 2, so as to permit the fluid to enter the recess 35 whence it may be delivered through the opening 44 via the

passages

34, 33, 31, 32, 41, and 43. The presence of fluid in the recess 35 will act against the sealing ring 39 so as to urge the latter radially outwardly into sealing engagement with all of the sleeves 37 except those where the ring is displaced radially inwardly, thereby preventing leakage of fluid from the take-off device 27.

At the opposite ends of the inwardly deformed portion of the wall 12, the inner surface of the wall section 13 is stressed in compression so those portions of the wall on opposite sides of the slits are forcibly squeezed toward one another to seal the slits. The angular disposition of the slits permits the opposed edges of the wall to move relatively to one another to avoid puckering and thereby maintain sealing engagement on opposite sides of each slit. As a further safeguard against leakage at opposite ends of the deformed portion of the wall, the beads 38, being slightly larger than the bores 25, will enter and snugly engage the walls of the bores. Should any fluid seep past the slits, it will be received in the sleeves for delivery to the annular recess 35.

In use, the take-off device 27 may be moved longitudinally of the conductor, either by pulling or pushing the take-off device or by incorporating in the latter a fluid motor of the kind disclosed in Patent No. 3,012,574. In either event, movement of the take-off device along the conductor will result in the deformation of successive portions of the wall 12 inwardly of the housing so as to maintain constant communication between the take-off device and the chamber 23. As the take-off device traverses the length of the fluid conductor, successive beads 38 on the periphery of the take-off device will enter successive ports in the resilient wall and thereby maintain the associated passages through the annular member 29 in alignment with the ports in the resilient wall. Moreover, the protruding beads 38 will prevent skidding of the take-01f de vice on the conductor wall.

The embodiment of the invention disclosed in FIG-

URES

5 and 6 is generally similar to the embodiment previously described, and similar parts are identified by similar reference characters. The difference between the two embodiments is in the construction of the deformable walls. In the embodiment disclosed in FIGURES 5 and 6, the deformable wall 12a has a hollow core 51 formed in and extending longitudinally of the enlarged center section 13. Those portions of the wall 12a inwardly and outwardly of the core may be considered inner and outer partitions, respectively. Each of the ports 25 communicates with the core 51 and receives a valve member 52 having a rounded head 53 located in the core and a stem 54 received in the port 25. The diameter of the stem 54 is not as great as the diameter of the port in which it is received, and the length of the stem is such as to permit the valve to be displaced vertically upon engagement of the stern by a bead 38 on the annulus 29. The free end of each valve stem 54 is tapered so as to avoid any possibility of closing the opening through the associated bead 38, and each stem 54 is transversely slotted as at 55 to assure the passage of fluid through the port 25 and into the sleeve 37.

The core 51 communicates with the fluid chamber 23 through a plurality of passages 56 so that the pressure of fluid in the chamber constantly exerts a force on the valves 52 urging them into sealing relation with the ports 25. The number of passages 56 may correspond to the number of ports 25, but exact correspondence is not essential.

In the modified embodiment of the invention it is not necessary to deform the wall 12a as much as was the case Wtih the wall 12. It is only necessary that the radial projection of the beads 3.8 and the length of the valve stems 54 be so related to one another as to assure unseating of the valve heads 53 by the beads.

The disclosed embodiments are representative of pres ently preferred forms of the invention, but are intended to be illustrative rather than definitive thereof. The invention is defined in the claims.

We claim:

1. A conduit adapted to carry fluid under pressure and being tappable at any selected point along its length, said conduit comprising means defining a substantially hollow chamber having at least one deformable wall formed of resilient material, said wall having a plurality of externally open bores spaced along the length thereof and extending from the outer face of said wall toward said chamber but terminating short thereof, said wall being slit obliquely to its length at each of said bores, each of said slits extending from said chamber at least to the point of termination of its associated bore and intersecting the latter, the wall portions on either side of each slit normally abutting one another so as to provide a plurality of normally closed openings along the length of said wall, said wall being deformable in a direction into said chamber so as to separate said normally abutting wall portions and permit communication between said slits and said bores.

2. The construction set forth in claim 1 wherein said wall comprises a centrally disposed, relatively thick strip joined on each side to a relatively thin strip, the terminal edge of each of said relatively thin strips being enlarged.

3. The construction set forth in claim 1 wherein said conduit comprises a housing having three sides joined to one another and a fourth side formed by said deformable wall, said wall spanning the distance between two sides of said housing, and cooperable means on said two sides and on opposite edges of said wall for securing said wall to said two sides in fluid tight relation.

*4. In a fluid conductor and take-off assembly, means forming an enl-ongate, substantially hollow fluid chamber for containing fluid under pressure, said chamber having at least one wall formed of resilient, deformable material, said wall having a plurality of longitudinally spaced, normally closed openings therein in communication with said chamber and adapted to be opened upon deformation of said wall inwardly of said chamber; fluid take-off means having a number of spaced apart, ported projections thereon, the spacing between adjacent projections on said takeoff member corresponding substantially to the spacing between adjacent openings in said wall; and means mounting said take-01f means for movement longitudinally of i said chamber in engagement with said wall, whereby said 1 projections register with said normally closed openings in said wall and deform the latter inwardly of said chamber to open said openings in the region of deformation of said wall.

5. The construction set forth in claim 4 wherein each of said openings in said wall includes an externally open bore extending in a direction inwardly of said chamber.

6. The construction set forth in claim 5 wherein each i of said bores terminates short of said chamber, said wall being slit at each bore from said chamber at least to the terminus of said bore to intersect the latter and provide communication between said bore and said chamber.

7. The construction set forth in claim 6 wherein each of said slits extends obliquely to the length of said wall. 8. The construction set forth in claim 5 including valve I means in each of said bores engageable by the projections on said take-of: means.

9. Fluid conductor and take-off apparatus comprising walls forming an elongate, hollow conduit adapted to conbular projection mounted on said wheel at each opening therein and extending radially beyond the peripheral edge of said wheel; and means mounting said wheel for movement longitudinally of said conduit with a portion of the peripheral edge of said wheel in engagement with said wall and with the projections associated with said peripheral edge portion received in the adjacent openings in said wall.

10. The construction set forth in claim 9 wherein said wall is formed of resilient material, and wherein said peripheral portion of said wheel deforms the engaged portion of said wall inwardly of said housing.

11. The construction set forth in claim 10 wherein each of the openings in said wall comprises a bore extending inwardly of said hOusing from the outer surface of said wall but terminating short of the inner surface thereof, and a slit in said wall extending from the inner surface of said wall toward and communicating with said bore.

12. The construction set forth in claim 11 wherein said slit extends obliquely to the length of said wall.

13. The construction set forth in claim 9 wherein each of said openings in said one wall comprises a bore extending from the outer surface of said wall to the inner surface thereof, and a movable valve member positioned in said bore, said valve member being displaceable inwardly of said housing by engagement with one of said projections on said wheel.

14. The construction set forth in claim 9 wherein said wall has a hollow core, said openings in said wall comprising externally open ports communicating wtih said core and other ports communicating with said core and the interior of said housing.

15. The construction set forth in claim 14 including movable valve means in each of the externally open ports, said valve means being displaceable inwardly of said housing by engagement with one of said projections on said wheel.

16. Apparatus for use in a fluid conductor, said apparatus comprising an elongated member formed of flexible, resilient material having opposite surfaces, said member having a plurality of spaced apart bores therein each of which extends from one of said surfaces toward the other and terminates short of said other surface, said member having a number of slits therein corresponding to the number of said bores and spaced accordingly, each of said slits extending from said other surface toward said one of said surfaces but terminating short of the latter, each of said slits intersecting its associated bore, and each of said slits extending obliquely to the length of said member.

17. Apparatus for use in a fluid conductor, said apparatus comprising an elongated member formed of flexible, resilient material having opposite surfaces, said member having a hollow core between said surfaces, said member having a plurality of spaced apart bores therein each of which extends from one of said surfaces to said core, said member having a number of passages therein spaced longitudinally of said member and extending from the other surface of said member to said core; and valve means for selectively closing and opening each of said bores.

18. A fluid conductor and take-off assembly comprising: a conduit adapted to carry fluid under pressure and being tappable at any selected point along its length; said conduit comprising an elongated rigid member defining three sides of said conduit, and a deformable member formed of resilient material defining the fourth side of said conduit; said deformable member comprising a central section joined on opposite edges to side sections, said central section being less flexible than either of said side sections, and an enlargement at the terminal edge of each of said side sections; said central section of said deformable member having longitudinally spaced, normally closed openings extending transversely therethrough and being opened in response to deformation of said deformable member; said rigid member being provided with longitudinal grooves, adjacent to the terminal edges thereof, for receiving said terminal edge enlargements of said deformable member; a pair of elongated clamping members dimensioned to be clamped over the terminal edges of said rigid member, one terminal edge of each clamping member partially closing an associated longitudinal groove of said rigid member to confine the terminal edge enlargement of said deformable member received in said groove; fluid-take-off means having an arcuate surface; and means mounting said take-off means for movement along said rigid member with said arcuate surface in engagement with said deformable member to deform the latter into said conduit, the deformation of said deformable member by said take-01f means opening said normally closed openings in the region of deformation thereof.

19. The construction set forth in claim 18 wherein said normally closed openings are formed in part by a plurality of bores in said central section and spaced from one another longitudinally, each of said bores extending in a direction from the outer surface thereof inwardly toward said chamber.

20. A fluid conductor and take-off assembly comprising a housing having an open side; a deformable wall formed of resilient material, said wall having a central, flexible strip joined on its opposite sides to side strips having greater flexibility than said central strip; said central strip having fluid passage means therein formed by a plurality of bores spaced from one another longitudinally of said wall; valve means positioned in each of said bores; means anchoring said side strips of said wall to said housing to form a hollow, four-sided chamber adapted to contain fluid under pressure; fluid take-off means having an arcuate surface; means mounting said take-off means for movement along said chamber with said arcuate surface in engagement with said wall; and valve operating means on said take-off means for operating said valve means.

21. A conduit adapted to contain fluid under pressure and being tappable at any one of a plurality of selected points along its length; said conduit comprising means defining a substantially hollow chamber for containing fluid under pressure and having one wall composed of inner and outer partitions joined to one another to provide a hollow core; said outer partition of said one wall being provided with a plurality of externally open ports spaced along the length of said wall; said inner partition being ported along its length to provide communication between said chamber and said core, and a valve member movably mounted in each of said ports in said outer partition and normally urged by fluid pressure into sealing relation with its associated port, each of said valve members being movable inwardly of said hollow core to permit communication between its associated port and said core.

22. Apparatus for forming a wall of an elongated fluid conductor: said apparatus comprising an elongated member formed of resilient flexible material and having a central section joined at opposite edges to side sections and an enlargement at the terminal edge of each of said side sections; each of said enlargements adapted to be confined by other walls of a fluid conductor; and said central section being less flexible than either of said side sections and having a plurality of longitudinally spaced, normally closed openings extending transversely therethroughadapted to be opened upon deformation of said central section.

23. The apparatus set forth in claim 22 wherein said terminal edge enlargements each comprise a substantially cylindrical bead and an upstanding rib integrally secured to said head.

24. A conduit adapted to carry fluid under pressure and being tappable at any selected point along its length;

said conduit comprising an elongated rigid member defining three sides of said conduit, and a deformable member formed of resilient material defining the fourth side of said conduit; said deformable member comprising a central section joined on opposite edges to side sections, said central section being less flexible than either of said side sections, and an enlargement at the terminal edge of each of said side sections; said central section of said deformable member having longitudinally spaced, normally closed openings extending transversely therethrough and being opened in response to deformation of said deformable member; said rigid member being provided with longitudinal grooves, adjacent to its terminal edges, for receiving said terminal enlargements of said deformable member; and'a pair of elongated clamping members dimensioned to be clamped over the terminal edges of said rigid member, one terminal edge of each clamping member partially closing an associated longitudinal groove of said rigid member to confine the terminal edge enlargement of said deformable member received in said groove.

25. A conduit adapted to carry fluid under pressure and being tappable at any selected point along its length; said conduit comprising an elongated rigid member defining three sides of said conduit, and a deformable member formed of resilient material defining the fourth side of said conduit; said deformable member comprising a central section joined on opposite edges to side sections, said central section being less flexible than either of said side sections, and an enlargement at the terminal edge of each of said side sections; said central section of said deformable member having longitudinally spaced, normally closed openings extending transversely therethrough and being opened in response to deformation of said deformable member; said rigid member being provided with longitudinal grooves, adjacent to its terminal edges, for receiving said terminal enlargements of said deforrnable member, and said terminal edges defining lips which project toward each other; a pair of elongated channel shaped clamping members, dimensioned to be clamped over said lips, one terminal edge of each clamping memher defining a head for partially closing an associated longitudinal groove of said rigid member to confine one of said terminal edge enlargements of said deformable member.

26. The construction set forth in claim 25 wherein said heads of said clamping members define supports for said deformable member, resisting outward deformation thereof.

27. The construction set forth in claim 25 wherein said heads of said clamping member define supports for said deformable member, resisting outward deformation thereof; and wherein said heads of said clamping members are spaced from each other to define an access groove to the central section of said deformable member, through which said deformable member may be engaged and deformed inwardly of said conduit by a fluid take-off member.

References Cited M. CARY NELSON, Primary Examiner.

W. CLINE, Examiner.

Claims

22. APPARATUS FOR FORMING A WALL OF AN ELONGATED FLUID CONDUCTOR: SAID APPARATUS COMPRISING AN ELONGATED MEMBER FORMED OF RESILIENT FLEXIBLE MATERIAL AND HAVING A CENTRAL SECTION JOINED AT OPPOSITE EDGES TO SIDE SECTIONS AND AN ENLARGEMENT AT THE TERMINAL EDGE OF EACH OF SAID SIDE SECTIONS; EACH OF SAID ENLARGEMENTS ADAPTED TO BE CONFINED BY OTHER WALLS, OF A FLUID CONDUCTOR; AND SAID CENTRAL SECTION BEING LESS FLEXIBLE THAN EITHER OF SAID SIDE SECTIONS AND HAVING A PLURALITY OF LONGITUDINALLY SPACED NORMALLY CLOSED OPENINGS EXTENDING TRANSVERSELY THERETHROUGH ADAPTED TO BE OPENED UPON DEFORMATION OF SAID CENTRAL SECTION.