CA1179393A - Quick-connect coupling for thin-walled pipes - Google Patents
Quick-connect coupling for thin-walled pipesInfo
- Publication number
- CA1179393A CA1179393A CA000434062A CA434062A CA1179393A CA 1179393 A CA1179393 A CA 1179393A CA 000434062 A CA000434062 A CA 000434062A CA 434062 A CA434062 A CA 434062A CA 1179393 A CA1179393 A CA 1179393A
- Authority
- CA
- Canada
- Prior art keywords
- coupling
- pipes
- coupling member
- quick
- pipe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L17/00—Joints with packing adapted to sealing by fluid pressure
- F16L17/02—Joints with packing adapted to sealing by fluid pressure with sealing rings arranged between outer surface of pipe and inner surface of sleeve or socket
- F16L17/04—Joints with packing adapted to sealing by fluid pressure with sealing rings arranged between outer surface of pipe and inner surface of sleeve or socket with longitudinally split or divided sleeve
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- Quick-Acting Or Multi-Walled Pipe Joints (AREA)
Abstract
ABSTRACT
A quick-connect coupling is disclosed for thin-walled pipes which can accommodate pipes of the same internal diameter but of differing wall thickness, the coupling member being constructed to deform pipes of less than maximum wall thickness into a substantially elliptical condition in which the coupling is fully seated, bolting pads of the coupling being spaced from each other to induce deformation and seating of the pipes upon tightening of the coupling.
A quick-connect coupling is disclosed for thin-walled pipes which can accommodate pipes of the same internal diameter but of differing wall thickness, the coupling member being constructed to deform pipes of less than maximum wall thickness into a substantially elliptical condition in which the coupling is fully seated, bolting pads of the coupling being spaced from each other to induce deformation and seating of the pipes upon tightening of the coupling.
Description
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-1- , , "~UIGI~-CONNECT COUPLING FOR THIN-~ALLED PIPES"
FIl~LD OF THE INVENTION
This invention relates to a coupling for pipeline assemblies employed for conveying fluids under pressure, and in particular re]ates to a coupling known in the art as a quick-conllect coupling comprising coupling members of segmented, usually semi-circular configuration which are employed to bridge the mutua1l~7 presented ends of a pair of pipes in sealing relationship, and secure the pipes against movement relatively to each other.
Such quick-connect couplings are clampingly engaged with the outer periphery of the pipe ends, an~ convenient arrangement such as bolts and nuts or lever actuated toggles being employed for securing the respectively clamping mernbers to each other, and~ for providing the required clarnping pressure on the pipes.
In order to provide for sealing of the pipe ends to each other and to prevent leakage or seepage of the pressurized fluid within the pipes in a direction either radially of the pipe ends or axially along the outer periphery thereof, either a single annular gasket member of an elastomeric material is positioned over the pipe ends in bridging relationship therewith prior to the coupling members being applied to the pipe ends, or, the respective coupling members are provided with gasket members of elastomeric material which are supported by the coupling members and which are brought into the required bridging and sealing relfltionship with the pipe ends upon the positioning of the coupling members over the pipe ends and the securing of the coupling members to each other. In either case, the couplinrr members are provided with a central groove within which the e}astomeric seal is received, the elastomeric seal being held under compression by the coupling members against the outer surface of the pipe ends.
Couplings of the type described above are known from United States Patent Serial No. 2,0~11,132, Johnson, issued May 19, 1936, in their utility in securing and sealing to each other the ends of thin-walled pipes formed from a material which is capable of being worked to provide locating members after formation of the pipes. In Johnson, the pi?e ends are worked subsequent to the formation of the pipe to provide circumfercntiall~ spaced radia]ly c~:tending arcunte projectioI7s on each of the adjacent pipe ends, .
~-2-the arcuate projections being r eceived within flnd held by interllal grooves located within and adjacent each axifll end of the coupling members. l~hen the coupling members are properly assembled about the pipc ends, the nrcl~ate projections are trapped within the grooves of the cOUplil~g members, rmd provide limited axial movement of the pipes relatively to each other, while restrainin~ them from separation.
BACKGRQUND OF T~E I~VENTION
In numerous industrial applications, such as in food or che;nical processing plants, and, in particular wood pulp handling and processing plants and paper manufacturing plants, the need arises to employ pipes formed from a material which is highly resistant to corrosion or etching by the conveyed fluids; and which is non-reactive with the fluid to be conve~ed and non-contaminating to that fluid. Stainless steel commonly is employed for this purpose. However, stainless steel is a high cost material requiring economies to be effected in its usAge. ~s a consequence, the wall thickness of the pipes must be Icept as small as is possible withill the design and operating parameters of the plant, it being uneconomical to employ stainless steel pipes of a maxirnum wall thickness, except in those circuln~stances which require maximum wall thickness. Commonly, such pipes formed from stainless steel are of a relatively light gfluge and have a wall thickness in the range of 0.078 to 0.109 inches, the range not necessarily being limited to such thickness.
While such selection of rninimal wall thicl;ness of the pipes is admirable for the reasons of economy, it tends to preclude the use of quicl;-connect couplings, in that a quicl;-connect coupling of specific dimensions must be provided for any specific wall thickness of pipe.
This requirernent arises in that the end faces of the coupling menlbers must be brought in to face contact with the faces of the oppos te coupling member, for otherwise, there will be a gap existing between the mutually presented pairs of end faces wllich will permit the extrusion or coid flow of the g~sket melnber at the interface of the coupling members, with A conscyuential loss of sealing pressure exerted on the elastomeric seal nnd seepage axially of the pipe ends, and, seepage at the radial interface of the gasket members in those instances ~ here the elastorneric seal is other thar conti nuous.
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This condition will arise when the outside diameter of a pipe is greatcr than that for which the coupling was designed. In the event that the outside diameter of the pipe is less than that for which the coupling was designed, then the end fAces of the coupling members will come into face contacl with each other, but, prior to the required compressive force being developed within the gasket member sufficient to ensure against seepage axially of the elastomeric seal or radially at the interface of the respective ends thereof.
Further, in the event that a coupling is applied to a pipe having an outside diameter which is less than that for which the coupling was designed, and the pipe is of the type having spaced radially extending arcuate projections for interlocl~ing with the couplinq, then, the interengagement between the projections and the coupling will be of diminished extent and will reduce the strenath of the interconnection.
OB~ECT OF Tl-IE INVENTION
It is an object of this invention to provide a quick-connect coupling which can be employed univelsally with pipes of ally ~vall th;cl;ness within a determitled range, thus eliminating the necessity of providing a coupling of specific dimensiorls to accommodate any particular wall thickness of pipe within that determined range.
SUMMARY OF THE INVENTION
According to the present invention, instead of being formed from coupling members in which the end faces of each coupling member are coplanar with the axis of generation of the couplingr member as in prior known constructions, the end faces of the coupling members are formed for them to be substantially planar and for each said end face to lie in a plane which is parallel to, but spaced from, a radia] plane ~hich includes the central longitudinal axis of generation of the coupling bore and which lies beyond the associated end of the coupling member.
Where the coupling member is comprised of t~o coupling member hlllves, as is most commonly the case, the respective end faces of each coupling member are coplanar, and the plane of the end faces is spaced from the axis of generation of coupling member half with said axis positioned on that side of said plane which is opposite to the side facing the COllp]ing member half. An extrusion shie]d in two parts, of fle~;ible :~ t yet som ewh~t rigid m eteriel is provi ded ~ the ol~ ter ;a ce of the '3~
elastomeric gasket mernber, the extrusion shield bridging any gap which may be present between the mutually presented end faces of the coupling members tllus maintflining the compressive for ce exerted on the gasket member and confining the elastomeric seal against exh~usion.
As will be apparent later in the discussion of the present invention, the compressive force exerted on the gasket member is maintained at or above fl minimurn optimum level without regard to the wa!l thickness of the pipe ~Yithin a determined range of thicknesses, advantage being taken of the ability of the pipe to flex and deform for it to be of other than truly circular transverse cross-section.
DESCRIPTION OF THE l)RAWINGS
The invention will now be described with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of a quick-connect coupling according to the present invention applied to the ends of a pair of pipes;
Figure 2 is a fragmentaly cross-section take along the line 2-2 in Figure 1;
~igure 3 is a cross-section takell along the line 3-3 in Figure 2 and showing the coupling of the present invention applied to a pipe having a maximum permissible ~all thickness; :
Figure 4 is a transverse cross-section taken on the line 4-4 in ~igure 2, again showing the coupling of the present invention applied to a pipe having maximum permissible wall thicl;ness;
Figures 5A and 5B are transverse cross-sections corresponding with Figllre 3, but showing tlle .
collpling of the present invention appLied to a pipe having minimum ~flll thickness, Figure SA ~;
showing the coupling assembled about the pipe end but prior to torquing of the bolts, and figure 5B showing the coupLing assembled about the pipe end and subsequent to the torquing of the bolts;
Fi~rure 6 is a transverse cross-section corre-sponding with Ficure 4, showing the coupling of -s-the present invention app~ied to a pipe of minimfll wall thickness;
Figul e 7 is a fragmentary cross-section similar to Figure 2, but illustratng a flanged quick-connect coupling nccording to the present invention applied to the end of a single pipe;
Figure 8 is a fragmentary perspective view of the sealing gasket employed in the flanged coupling of Figure 7; and, Figure 9 is a fragmentary perspective view of an alternative form of sealing gasket for use in the quick-connect coupling of any one of Figures 1 through 6.
Referring now to the drawings, the quicli-connect coupling of ;
the present invention is indicated generally by the referellce numeral lO, the coupling being shown as applied to, and interconnecting the ends of pipes ll and l~. The coupling is comprised of coupling member halves l~
which are identical witll each other in aU respects in the cflse of pipes having an internal diameter which is identical with that of the internal diameter of the other pipe, as is most com monly the case. The present invention does not, however, preclude a ste~up or step-down in the internal diameter of the respective pipes.
In relation to the flpplication of the invention as a step-up or step-down coupling, in the practical case it is not necessary that the wall thickness be identical if one is willing to accept some tilting of the coupling and in fact even in pipes of common internal diameter but different wall thicknesses, it has been proven practical to use the coupling, for e7~ample~
to join a pipe of .078" wall to a pipe of .109" wall. Further with regard to the abilities of the coupling, it should be recognized that the coupling can also be used to accomodate pipe of a specific wall thickness but with O.D.
variations, e.g. due to tolerances lying w ithin the design range of the coupling.
The respective coupling member halves may be formed in any s~1itable manner, such as b~7 casting or forging, and, may be formed of any suitable material, such as cast or malleable iron or steel. Where conditions warrant, the coupling mernber halves may be formed from a materi~l :
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identical with that of the pipes, ior example, stainless steel. Optionally, the coupling member halves may be formed by injection molding a s~itable ;
rigid plastics material, particularly in those instances whel e electrical continllity between the respective pipes ~ ould be disadvantageous. , Each coupling member half includes bolting pads 16 formed integrally therewith, the bolting pads 16 having apertures for the reception of bolts 1~. The bolts 17 are received within nuts 18, and act to sec~lre the respective clamping member halves to each other in clamping engagement with the exterior surface of the respective pipes 11 and 12. In a preferred construction, the shanks of the bolts are other than of circular transverse cross-section, and, are received within correspondinglv shaped apertures in the bolting pads 16 for the bolts to be held against rotation within the lugs. In this rnanner, the requirement for two independent wrenches for torquing the bolts is removed, only on such wrenC}l heing necessaly. Optionally, the bolts may be coach bolts having a neck portion which is rectangular in transverse cross-section, or, the neck portion can be formed of oval or other non--circlllar transverse cross-section.
Each coupling member half includes a central groove 20 within which is received a sealing gasket 21. The gMsket may be formed of any suitable elastomeric material, and, may be of any desired configuration in transverse cross-section, as is ~ell known in the art. The gasket 21 is contailled within a retainer 22 of split or segnlented construction, the retainer 22 or the respective segments thereof being located for them to bridge any gnp ~ hich may be present between the respective pairs of bolting pads 16, 16. The retainer 22 has a transverse cross-section complimentary to the outer peripheral contour of the gasket 21 and the contour of the groove 20, and is formed from a substMntially rigid but flexible rnaterial such as stain]ess steel or carbon steel, or, where opernting conditions permit, a stiff but flexible p]astics material. ()ptionallv, the gasket r etainers 22 may be of foreshortened dimensions moulded integrally ~ith the gasket and flush with the outer surface of the gasket, two o' these being di~metrically opposed, this prc)viding the beneîit of a unitary sub-assembly and greater convenience in nssembly.
Adjacent each axial end of the collpling member ihalves, the ;
couplill(J member halves are formed ~ith an int*rnal groove 24 for the reception of arcuate projections 2~ forrned in the res?ective pipes ll and 3 ;~r3, 3 '1.
12, and which extend radially outwardly of the respective pipes and are spaced circumferentially about the periphery thereof. The projections 25, in conjunction with the grooves 24 in tlle nssernbled coup]in~, prevent separation of the pipes under the flction of end pull forces and limit axial Y
movement of the pipes with respect to each other. i The construction so far described finds counterpar t in U.S. b`
Patent No. 2,041,132 referred to above, and does not constitute the focal point of the present invention. c Referrinrr now more particularly to Figures 3 and 4, which illustrates the coup1ing of the present invention applied to a pipe having ;
maximum permissible wall thickness, it will be noted that the radius of the interior bore of each coupling member half is identical with the raclius of the outer surface of the pipe, such that, thro-lghout its entire arcuate .
extent, the inner periphery of the coupling member is in engagement with .
the outer surface of the pipe, each of the projections 25 being fully received ,,, within its associated groove 24. In this condition, as more clearly illllstratedin Figures 3 and 4, the end faces 16a of the respective bolting pads 16 of the respective coupling member halves are spaced from each other, the ~
gaps between the respective pairs of end fnces 16a, which have bcen shown .
exaggerated in the drawings, being bridged by the gasket 21 and the gflsliet retainer 2~. Even in the event thnt the bolts 17 are torqued fully in order to place the gasket under the required compressive force, extrusion of the gasket through the gaps between end faces 16a is inhibited by the gasket retainer 22, which ncts to distribute the compressive forces actin~ on the sealing gasket 21 e~ufllly throughout the entire circumierence thereof. ;
As is clearl~1 illustrated in Figures 3 and 4, the end faces 16a of the respective pairs of bolting pads 16 of the respective coupling member halves are coplan~r, the plane of the respective pairs of end faces 1~a being indicated by the chain-dotted lines A1 and ~2.
In Figures 3 and 4, which illustrate the coupling of the present invention as applied to a pipe of ma iimum wall thickness within a determined rn~CJe of thic~inesses, each of the coupling membei halves 14 is in continuous engagemerlt at its inner peripherv with the outer peripheral wall of the associate pipes. Under these corlditions, ecqch of the arcuate projections 25 is fully r-eceived within its nssociated groove 2~, such that maximum restraint is imposed on movement of the respective pipes axia11v relatively to e~qc'l I
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other, or, angularly relatively to each other. FIII ther~ in view of the continuous engagement of the inner periphery of the coupling members with the outer wall of the pipe, distortion of the pipe from its truly circulflr condition does not occur.
Continuous engagement of the inner periphery of the coup]ing member halves with the outer wall of the pipe is ensured by arr anKir,g for the radius R of the inner periphery of the clamping member halves to be iàentical with the radius of the outer periphery of pipes having maxirnum wall tllickness, the radius of the inner periphery of the respective coupling member halves and that of the outer wall of the tube being taken from a common longitudinal axis of generation indicated at B. It will be noted that the longituAinal axis of generation B is located intermediate and Inid way between the planes A1 and A2 of the end faces 16a of the bolting pads 16.
Referring now to Figures 5A, 5B and 6, which illustrate the coupling of the present invcntion when used in association with pipes having a minimum wall thickness, it is firstly to be observed that the coupling member halves 14, the gaslcet 21 and the gasket retainer 22 are identical in all respects with and are in fact the same as those employed in the embodiment of Figures 3 and 4, the sole difference in Figures SA, SB and 6 being ~that the pipes to be connected are of lesser wall thickness than the ones illustrated in Figures 3 and 4, the internal diameter of the pipes being identical.
Referr;ng more particularly to Figure 5A, which shows the assembly prior to the application of torque to the bolts, the respective coupling member halves rest on the outer wall of the pipe, which at that time is truly circular in transverse cross-section, contact between the inner periphery of the collpling mernbers 14 and the respective pipes occuring at positions interrnediate and substantially mid-way between the respective ends of the coupling members. Under these conditions, flnd having regard to the lesser outside diameter of the pipe, the arcuate projections 25 do not engage fully within the respective grooves 24, and, the respective members only engage the respective pipes in line engagement.
If, as in a conventional quick-connect coupling, the end faces 16a of the bolt;ng pads 16 ~, ere at this time in face enagement with each other, then, two entirely disadvantageous conditions arise. Firstly, restraint .
.
_9_ on relative axial or angular movement of the pipes is reduced or impaired owing to the incomplete engagement of the arcuate projections within their f~ssociated grooves, and secondly, there is a crescent-shaped gap indicated at C between the outer periphery of the pipes and the respective cou?ling 'member halves, which will resnlt ;n incomplete seating of the inner periphery of the coupling member halves on the outer periphery of the pipe, and, will resu]t in the compressive stress exerted on the gasket member being of progressively decreasing intensity from the mid-point of the respective coupling members towards the ends thereof. This will or can result in , incomplete sealing of the pipes by the coupling, with consequential seepage axially of the outer periphery of the pipe, and, in the case where split gaskets are employed, also can result in seepage at the radial interface of 5-the respective gasket members. ~' These problerns are obviated in their entirety according to the Ir present application, by arranging for the end faces 16a of the respective bolting pads 16 to be spaced from each other prior to and during torquing of the bolts, with the results which will now be discllssed with reference to I~igur e SB.
Upon torquing of the bolts, the respective coupling member halves, which already are in line engagelnent with the outer surface of the pipe at a point mid~'way between their ends, will exert a radially inward force on the pipes at those positions, and will stress the pipes causing'them to deform from a truly circular transverse cross-section to a transverse cross-section which is substantially elliptical, the major axis of the ellipse lying in a plane coincident ~vith or parallel to the respective planes A1 and ~2 of the ends faces of 16a ot` the respective bolting pads.
In distorting or deforming to sustantially elliptical configuration, the radius R1 along the major axis of the ellipse wiU
progressively increase, and, the radius R2 along the minor axis will pro~ressively decrease, thus forcing the entire outer periphery of the pipes into intimate seating engagemellt witll the inner periphery of the coupling .
members 14, and~ thus forcing the arcuate pr~jections 25 into full seating engagement within their associated grooves 24. Further, as the bolts are progressively torqued the pipes will progressively qssume a shape in ~hich they are in continuous engagement wit]l the gas!~et, and, in which the ~i compressive stresses in the gasl;et are equalized throughout the entire ~
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circumference thereof. In this w~y, the problem of seepage either axially of the outer periphery of the pipes, or rad;ally through the interface of the gasket members where a split gasket is employed, is elirninated in its entirety.
It ~ill be appreciated that in finally assembled condition of the coupling, the transverse cross-section of the respective pipes wil~ deviate slightly from an elliptical condition, the cross-section being theoretically that of two overlapping semicircular segments which intersect eacn other at the plane of the respective bolting pads, which, at that time are coincident with the centroid B of the pipes. The original longitudinal axis o~^ generation B of the respective coupling member halves now lie above and below the centre of the pipes as shown in Figure 6.
~ or pipes of a wall thickness intermediate the minimal wall thickness illustrated in Figures 5A, 5B and 6 and the maximum wall thickness illustrated in Figures 3 and 4, continuous engagement of the outer sllrface of the pipes with both the coupling member halves and the gasket member will occur and full seating and sealing will;be obtalned, the sole difference ~:
being that, with a progressive increase in wall thickness of the pipes, a pro"ressively increasing gap will occur between the respectiYe pairs of end faces 16A of the bolting pads 16.
The advantages accruing from ;the present invention stem from determined dimensional relationships bet~veen the coupling members and the range of wall thickness of the pipes to be accommodated by said coupllng members.
As will be~ readily apparent, in order to obtnin continuous seating of the coupling member halves relati~rely to a pipe having maximum wall thickness, then, the radius of the inner periphery of the respective .
coupling members must be identical with the `radius of the outer surface ~r of the periphery of the pipe.
If one assumes a range of pipes having the same internal .
diameter D, and having a minimum thickness T1 and a maximum thickness i~
T2, then, the radius R of the inner periphery of the respective coupling ~?-member halves must be D +22 ~T2) ~ n the other hand, in order to accommodate pipes of a wall thickness at the minimum end of the range, the combined lengths of the inner periphery of the coupling member halves must not be more than the -,~
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length of the circumference of the outer surface of such pipes of minimum wall thickness. This relationship can be expressed as ~ (D ~ 2T1) .
This relationship is critical, in that if the combined lengths of the inner peripheral walls of the coupling members is greflter than the 'length of the circumference of the exterior surface of a pipe minimum wall thickness, then, the end faces 16a will engage each other prematurely and prevent further elliptical deformation of the pipe prior to reachinb the required seating and sealing of the external periphery of the pipe relatively to the clamping members and the gasket.
While there has been described a coupling comprised by coupling member halves, it will be fuliy appreciated that for certain applications the' coupling members could be comprised by more than two f-coupling members, for example, three coupling members with the bolting pads arranged in Y arrangement. Provided that each such coupling rnernber is formed with its inner periphery of a radius identical with the radius of i the outer surface of a pipe of ma~cimum wall thickness, and, provided that the combined len~ths of the inner periphery of the respective coupling members does not exceed the circumfercntial length of the outside surface of a pipe of mininum wall thickness, then, exactly the same desirable conditions will be obtained as those discussed above with respect to a two-part coupling. The only difference will be that the cross-section of ~
the tube will be deformed or displaced into three segments instead of two, ~c' each of which will seat fully on the inner periphery of the assembled coupling, with full engagement of the arcuate projections ~5 within the grooves 24, full engagernent of the respective coupling members with the outer periphery of the pipes, and, full seating of the contained gasket mernber with the outer periphery of the pipes and equalization of the compressive stresses e~erted on the gasket member.
It will be appreciated that the structures illustrated in the `
drawings are by way of example only, and, that various modifications may be made within the scope of the invention as defined by the appended claims.
ln par~iculflr, while the invention has been described in relationship to thin-walled pipes which have been provided with radially outwardly extending arc~late projections, the coupling could also be used Witil plain' ended pipes devoid of such arcuate projections in those situations -where relative axial movement between the pipes cannot occur Optionally, ~ ~,t3~33 jl elamping ja~Ys having ineisor teeth eould be ineorporated into the grooves of the coupling members, or, the coupling members themselves eould be formed with incisor teeth to provide nn fldditional grip on plain-ended pipes.
Alternatively, the pipes could be inwardly dimpled at cireumferentially spaced positions and tile eoupling rnembers provided with corresponding dogs or teeth for entry into sueh dimples, the major consideration being that the formation of the pipes ~ith either arcuate radially outwardly extending projections or arcuAte radially inwarding extending dimples shall not interîere materially with the eapability of the pipes to distort or deform from their truly eireular eondition to a eondition of plural or multiple segments each having an outer radius whieh is that of the radius of the outer surface of a pipe having maximum wall thiekness.
Further, while the invention has been described with reference to a double-ended coupling for conneeting the adjacent ends of a pair of pipes to each other, the invention has equal applieation in a flanged, single-ended coupling employed for conneeting a pipe end to an adjacent structure.
Figure 7 illustrates such a flan~ed coupling, the coupling ineorporating all of the design parameters set out above with respect to the coupling of Figures I through 6, the major differences being in the adaptation of the coupling of Figures 1 through 6 to the form of a flanged coupling.
In Figure 7, the eoupling member, indicated generally at 30, is shown applied to the end of a pipe 31 having spaced radially extending arcuate projections 32 adjacent the free end thereof.
In an identical manner to that described above Yith reference to the coupling of Figures 1 through 6, the flanged eoupling 30 of Figure 7 ineludes coupling member halves 33 and 34 having radially extending bolting pads 35 and 36, which are secured to each other by bolts 37 and torqueing nuts 38, as previously described, in clamping engagement with the exterior surface of the pipe 31.
Each of the coupling member halves 33 and 3-1 includes a groove 39 for the reception of radially extending arcuate projections 32 formed adjflcent the end of the pipe 31, again, in the same manner as that discussed above with r espeet to Figures 1 through 6, and, each of the coupling mem~cr hnlves 33 and 34 includes a recess 4~ in which is received a gas~et mernber 41 ~hich is formed from any suitable elastomeric mate, ial.
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The respective coupling member halves each include a radially extending flange 42 having bolt holes 43 at circumferentially spaced !~
positions, whereby the flanges may be attached to an adjacent structllre having a planar face, or, whereby the flanges may be attached to the flanges of a similar or identical coupling attached to the end of another pipe, the said other pipe either being identical in dimensions with the pipe 31, or1 differing therefrom in respect of its internal radius or wall thickness. .
Conveniently, and as illustrated, the bolting pads 35 are provided with a rectangular key 35A which is received ~rithin a rectangular ~
keyway 36a in the bolting pads 36. The provisions of the key and keyway ':r acts to stabilize the respective coupling member halves on the end of the pipe during the assembly of the coupling onto the pipe end, and, further acts to ensure that the planar end faces of the coupling mernber halves are brought into co-planar relatio1lship with each other prior to the ~langes being at tached to the said adjacent structure.
In order not to interfere with the design parameters of the coupling, the keys 35a nre of a height no greater than the depth of the keyways 36a, the keys 35a preferably being of lesser height than the depth , of the keyways 36a. Additionally, the bolt holes 43 either are formed oversized in relationship to the bolts which extend therethrough, or, they are for~ed elongate in a direction radially of the longitudinal axis o~ the pipe and coupling. In this way, radially outward or radially inward movernents of the coupling member halves which are required in order to accomodate pipes of different wall thicl<ness can be accomodated without the necessity of repositioning the bolt holes in the structure to ~hich the cou?ling and pipe is to be attached.
Referring now to Figure 8, which illustrates in greater detail the gasket employed in the embodiment of Figure 7, the gasket includes a generally axially extending lip seal 41a for engagement with the outer periphery of the pipe, and includes a generally r adially extending lip seal ;
41b for sealing engagernent t^~ith the said adjacerlt structure to which the coupling is attached. r~
Conveniently, and as illustrated in Figure 8, instead of being r~
contained within a substantially continuous retainer or extrusion shield as described with reference to Figures 1 through 6, e~trusion shields ~4 are provided as an integral part of the gasket 41J the extrusion shields 44 being , l393 placed in 1I mold prior to the molding of the gasket, and thus being locsted in situ in the finished gasket. The provision of the extrusion shields 44 as an integral part of the gasket greAtly facilitates hnndl}ng of the gasket at the point of assembly at the coupling, and, eliminates the requirement for a separate extrusion shield or retainer. In use, the gasket is placed on the end oî the pipe, and, is then rotated to a position at which it will span the adjacent ends of the respective coupling member halves, subsequent to which the bolts are torqued down to fully assemble the coupling onto the pipe end.
Referring now to Figure 9, the same modification as is discussed above with respect to Figure 8 is shown as applied to the sealing gasket 21 of Figures 1 through 6. In Figure 9, respective segments 22a of the retainer are located at diametrically opposed positions within the mold employed for forming the sealing gasket 21, and thus become an integral part of the gasket during the molding process.
Preferably, the respective retainer segments 22a and 44 are either formed for them to be reflective, or, are formed or otherwise colored for them to be clearly distinguishable from the body of the sealing gasket 21. By so doing, the positlon of the retainers easily can be observed by an operative assembly the coupling, who will be given a visual indication that the retainers are correctly positioned relatively to the adjacent faces ~ .~
of the resRective pairs of bolting pads, in the manner indicated in chain- ;
dotted lines in Figure 7.
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-1- , , "~UIGI~-CONNECT COUPLING FOR THIN-~ALLED PIPES"
FIl~LD OF THE INVENTION
This invention relates to a coupling for pipeline assemblies employed for conveying fluids under pressure, and in particular re]ates to a coupling known in the art as a quick-conllect coupling comprising coupling members of segmented, usually semi-circular configuration which are employed to bridge the mutua1l~7 presented ends of a pair of pipes in sealing relationship, and secure the pipes against movement relatively to each other.
Such quick-connect couplings are clampingly engaged with the outer periphery of the pipe ends, an~ convenient arrangement such as bolts and nuts or lever actuated toggles being employed for securing the respectively clamping mernbers to each other, and~ for providing the required clarnping pressure on the pipes.
In order to provide for sealing of the pipe ends to each other and to prevent leakage or seepage of the pressurized fluid within the pipes in a direction either radially of the pipe ends or axially along the outer periphery thereof, either a single annular gasket member of an elastomeric material is positioned over the pipe ends in bridging relationship therewith prior to the coupling members being applied to the pipe ends, or, the respective coupling members are provided with gasket members of elastomeric material which are supported by the coupling members and which are brought into the required bridging and sealing relfltionship with the pipe ends upon the positioning of the coupling members over the pipe ends and the securing of the coupling members to each other. In either case, the couplinrr members are provided with a central groove within which the e}astomeric seal is received, the elastomeric seal being held under compression by the coupling members against the outer surface of the pipe ends.
Couplings of the type described above are known from United States Patent Serial No. 2,0~11,132, Johnson, issued May 19, 1936, in their utility in securing and sealing to each other the ends of thin-walled pipes formed from a material which is capable of being worked to provide locating members after formation of the pipes. In Johnson, the pi?e ends are worked subsequent to the formation of the pipe to provide circumfercntiall~ spaced radia]ly c~:tending arcunte projectioI7s on each of the adjacent pipe ends, .
~-2-the arcuate projections being r eceived within flnd held by interllal grooves located within and adjacent each axifll end of the coupling members. l~hen the coupling members are properly assembled about the pipc ends, the nrcl~ate projections are trapped within the grooves of the cOUplil~g members, rmd provide limited axial movement of the pipes relatively to each other, while restrainin~ them from separation.
BACKGRQUND OF T~E I~VENTION
In numerous industrial applications, such as in food or che;nical processing plants, and, in particular wood pulp handling and processing plants and paper manufacturing plants, the need arises to employ pipes formed from a material which is highly resistant to corrosion or etching by the conveyed fluids; and which is non-reactive with the fluid to be conve~ed and non-contaminating to that fluid. Stainless steel commonly is employed for this purpose. However, stainless steel is a high cost material requiring economies to be effected in its usAge. ~s a consequence, the wall thickness of the pipes must be Icept as small as is possible withill the design and operating parameters of the plant, it being uneconomical to employ stainless steel pipes of a maxirnum wall thickness, except in those circuln~stances which require maximum wall thickness. Commonly, such pipes formed from stainless steel are of a relatively light gfluge and have a wall thickness in the range of 0.078 to 0.109 inches, the range not necessarily being limited to such thickness.
While such selection of rninimal wall thicl;ness of the pipes is admirable for the reasons of economy, it tends to preclude the use of quicl;-connect couplings, in that a quicl;-connect coupling of specific dimensions must be provided for any specific wall thickness of pipe.
This requirernent arises in that the end faces of the coupling menlbers must be brought in to face contact with the faces of the oppos te coupling member, for otherwise, there will be a gap existing between the mutually presented pairs of end faces wllich will permit the extrusion or coid flow of the g~sket melnber at the interface of the coupling members, with A conscyuential loss of sealing pressure exerted on the elastomeric seal nnd seepage axially of the pipe ends, and, seepage at the radial interface of the gasket members in those instances ~ here the elastorneric seal is other thar conti nuous.
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This condition will arise when the outside diameter of a pipe is greatcr than that for which the coupling was designed. In the event that the outside diameter of the pipe is less than that for which the coupling was designed, then the end fAces of the coupling members will come into face contacl with each other, but, prior to the required compressive force being developed within the gasket member sufficient to ensure against seepage axially of the elastomeric seal or radially at the interface of the respective ends thereof.
Further, in the event that a coupling is applied to a pipe having an outside diameter which is less than that for which the coupling was designed, and the pipe is of the type having spaced radially extending arcuate projections for interlocl~ing with the couplinq, then, the interengagement between the projections and the coupling will be of diminished extent and will reduce the strenath of the interconnection.
OB~ECT OF Tl-IE INVENTION
It is an object of this invention to provide a quick-connect coupling which can be employed univelsally with pipes of ally ~vall th;cl;ness within a determitled range, thus eliminating the necessity of providing a coupling of specific dimensiorls to accommodate any particular wall thickness of pipe within that determined range.
SUMMARY OF THE INVENTION
According to the present invention, instead of being formed from coupling members in which the end faces of each coupling member are coplanar with the axis of generation of the couplingr member as in prior known constructions, the end faces of the coupling members are formed for them to be substantially planar and for each said end face to lie in a plane which is parallel to, but spaced from, a radia] plane ~hich includes the central longitudinal axis of generation of the coupling bore and which lies beyond the associated end of the coupling member.
Where the coupling member is comprised of t~o coupling member hlllves, as is most commonly the case, the respective end faces of each coupling member are coplanar, and the plane of the end faces is spaced from the axis of generation of coupling member half with said axis positioned on that side of said plane which is opposite to the side facing the COllp]ing member half. An extrusion shie]d in two parts, of fle~;ible :~ t yet som ewh~t rigid m eteriel is provi ded ~ the ol~ ter ;a ce of the '3~
elastomeric gasket mernber, the extrusion shield bridging any gap which may be present between the mutually presented end faces of the coupling members tllus maintflining the compressive for ce exerted on the gasket member and confining the elastomeric seal against exh~usion.
As will be apparent later in the discussion of the present invention, the compressive force exerted on the gasket member is maintained at or above fl minimurn optimum level without regard to the wa!l thickness of the pipe ~Yithin a determined range of thicknesses, advantage being taken of the ability of the pipe to flex and deform for it to be of other than truly circular transverse cross-section.
DESCRIPTION OF THE l)RAWINGS
The invention will now be described with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of a quick-connect coupling according to the present invention applied to the ends of a pair of pipes;
Figure 2 is a fragmentaly cross-section take along the line 2-2 in Figure 1;
~igure 3 is a cross-section takell along the line 3-3 in Figure 2 and showing the coupling of the present invention applied to a pipe having a maximum permissible ~all thickness; :
Figure 4 is a transverse cross-section taken on the line 4-4 in ~igure 2, again showing the coupling of the present invention applied to a pipe having maximum permissible wall thicl;ness;
Figures 5A and 5B are transverse cross-sections corresponding with Figllre 3, but showing tlle .
collpling of the present invention appLied to a pipe having minimum ~flll thickness, Figure SA ~;
showing the coupling assembled about the pipe end but prior to torquing of the bolts, and figure 5B showing the coupLing assembled about the pipe end and subsequent to the torquing of the bolts;
Fi~rure 6 is a transverse cross-section corre-sponding with Ficure 4, showing the coupling of -s-the present invention app~ied to a pipe of minimfll wall thickness;
Figul e 7 is a fragmentary cross-section similar to Figure 2, but illustratng a flanged quick-connect coupling nccording to the present invention applied to the end of a single pipe;
Figure 8 is a fragmentary perspective view of the sealing gasket employed in the flanged coupling of Figure 7; and, Figure 9 is a fragmentary perspective view of an alternative form of sealing gasket for use in the quick-connect coupling of any one of Figures 1 through 6.
Referring now to the drawings, the quicli-connect coupling of ;
the present invention is indicated generally by the referellce numeral lO, the coupling being shown as applied to, and interconnecting the ends of pipes ll and l~. The coupling is comprised of coupling member halves l~
which are identical witll each other in aU respects in the cflse of pipes having an internal diameter which is identical with that of the internal diameter of the other pipe, as is most com monly the case. The present invention does not, however, preclude a ste~up or step-down in the internal diameter of the respective pipes.
In relation to the flpplication of the invention as a step-up or step-down coupling, in the practical case it is not necessary that the wall thickness be identical if one is willing to accept some tilting of the coupling and in fact even in pipes of common internal diameter but different wall thicknesses, it has been proven practical to use the coupling, for e7~ample~
to join a pipe of .078" wall to a pipe of .109" wall. Further with regard to the abilities of the coupling, it should be recognized that the coupling can also be used to accomodate pipe of a specific wall thickness but with O.D.
variations, e.g. due to tolerances lying w ithin the design range of the coupling.
The respective coupling member halves may be formed in any s~1itable manner, such as b~7 casting or forging, and, may be formed of any suitable material, such as cast or malleable iron or steel. Where conditions warrant, the coupling mernber halves may be formed from a materi~l :
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identical with that of the pipes, ior example, stainless steel. Optionally, the coupling member halves may be formed by injection molding a s~itable ;
rigid plastics material, particularly in those instances whel e electrical continllity between the respective pipes ~ ould be disadvantageous. , Each coupling member half includes bolting pads 16 formed integrally therewith, the bolting pads 16 having apertures for the reception of bolts 1~. The bolts 17 are received within nuts 18, and act to sec~lre the respective clamping member halves to each other in clamping engagement with the exterior surface of the respective pipes 11 and 12. In a preferred construction, the shanks of the bolts are other than of circular transverse cross-section, and, are received within correspondinglv shaped apertures in the bolting pads 16 for the bolts to be held against rotation within the lugs. In this rnanner, the requirement for two independent wrenches for torquing the bolts is removed, only on such wrenC}l heing necessaly. Optionally, the bolts may be coach bolts having a neck portion which is rectangular in transverse cross-section, or, the neck portion can be formed of oval or other non--circlllar transverse cross-section.
Each coupling member half includes a central groove 20 within which is received a sealing gasket 21. The gMsket may be formed of any suitable elastomeric material, and, may be of any desired configuration in transverse cross-section, as is ~ell known in the art. The gasket 21 is contailled within a retainer 22 of split or segnlented construction, the retainer 22 or the respective segments thereof being located for them to bridge any gnp ~ hich may be present between the respective pairs of bolting pads 16, 16. The retainer 22 has a transverse cross-section complimentary to the outer peripheral contour of the gasket 21 and the contour of the groove 20, and is formed from a substMntially rigid but flexible rnaterial such as stain]ess steel or carbon steel, or, where opernting conditions permit, a stiff but flexible p]astics material. ()ptionallv, the gasket r etainers 22 may be of foreshortened dimensions moulded integrally ~ith the gasket and flush with the outer surface of the gasket, two o' these being di~metrically opposed, this prc)viding the beneîit of a unitary sub-assembly and greater convenience in nssembly.
Adjacent each axial end of the collpling member ihalves, the ;
couplill(J member halves are formed ~ith an int*rnal groove 24 for the reception of arcuate projections 2~ forrned in the res?ective pipes ll and 3 ;~r3, 3 '1.
12, and which extend radially outwardly of the respective pipes and are spaced circumferentially about the periphery thereof. The projections 25, in conjunction with the grooves 24 in tlle nssernbled coup]in~, prevent separation of the pipes under the flction of end pull forces and limit axial Y
movement of the pipes with respect to each other. i The construction so far described finds counterpar t in U.S. b`
Patent No. 2,041,132 referred to above, and does not constitute the focal point of the present invention. c Referrinrr now more particularly to Figures 3 and 4, which illustrates the coup1ing of the present invention applied to a pipe having ;
maximum permissible wall thickness, it will be noted that the radius of the interior bore of each coupling member half is identical with the raclius of the outer surface of the pipe, such that, thro-lghout its entire arcuate .
extent, the inner periphery of the coupling member is in engagement with .
the outer surface of the pipe, each of the projections 25 being fully received ,,, within its associated groove 24. In this condition, as more clearly illllstratedin Figures 3 and 4, the end faces 16a of the respective bolting pads 16 of the respective coupling member halves are spaced from each other, the ~
gaps between the respective pairs of end fnces 16a, which have bcen shown .
exaggerated in the drawings, being bridged by the gasket 21 and the gflsliet retainer 2~. Even in the event thnt the bolts 17 are torqued fully in order to place the gasket under the required compressive force, extrusion of the gasket through the gaps between end faces 16a is inhibited by the gasket retainer 22, which ncts to distribute the compressive forces actin~ on the sealing gasket 21 e~ufllly throughout the entire circumierence thereof. ;
As is clearl~1 illustrated in Figures 3 and 4, the end faces 16a of the respective pairs of bolting pads 16 of the respective coupling member halves are coplan~r, the plane of the respective pairs of end faces 1~a being indicated by the chain-dotted lines A1 and ~2.
In Figures 3 and 4, which illustrate the coupling of the present invention as applied to a pipe of ma iimum wall thickness within a determined rn~CJe of thic~inesses, each of the coupling membei halves 14 is in continuous engagemerlt at its inner peripherv with the outer peripheral wall of the associate pipes. Under these corlditions, ecqch of the arcuate projections 25 is fully r-eceived within its nssociated groove 2~, such that maximum restraint is imposed on movement of the respective pipes axia11v relatively to e~qc'l I
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other, or, angularly relatively to each other. FIII ther~ in view of the continuous engagement of the inner periphery of the coupling members with the outer wall of the pipe, distortion of the pipe from its truly circulflr condition does not occur.
Continuous engagement of the inner periphery of the coup]ing member halves with the outer wall of the pipe is ensured by arr anKir,g for the radius R of the inner periphery of the clamping member halves to be iàentical with the radius of the outer periphery of pipes having maxirnum wall tllickness, the radius of the inner periphery of the respective coupling member halves and that of the outer wall of the tube being taken from a common longitudinal axis of generation indicated at B. It will be noted that the longituAinal axis of generation B is located intermediate and Inid way between the planes A1 and A2 of the end faces 16a of the bolting pads 16.
Referring now to Figures 5A, 5B and 6, which illustrate the coupling of the present invcntion when used in association with pipes having a minimum wall thickness, it is firstly to be observed that the coupling member halves 14, the gaslcet 21 and the gasket retainer 22 are identical in all respects with and are in fact the same as those employed in the embodiment of Figures 3 and 4, the sole difference in Figures SA, SB and 6 being ~that the pipes to be connected are of lesser wall thickness than the ones illustrated in Figures 3 and 4, the internal diameter of the pipes being identical.
Referr;ng more particularly to Figure 5A, which shows the assembly prior to the application of torque to the bolts, the respective coupling member halves rest on the outer wall of the pipe, which at that time is truly circular in transverse cross-section, contact between the inner periphery of the collpling mernbers 14 and the respective pipes occuring at positions interrnediate and substantially mid-way between the respective ends of the coupling members. Under these conditions, flnd having regard to the lesser outside diameter of the pipe, the arcuate projections 25 do not engage fully within the respective grooves 24, and, the respective members only engage the respective pipes in line engagement.
If, as in a conventional quick-connect coupling, the end faces 16a of the bolt;ng pads 16 ~, ere at this time in face enagement with each other, then, two entirely disadvantageous conditions arise. Firstly, restraint .
.
_9_ on relative axial or angular movement of the pipes is reduced or impaired owing to the incomplete engagement of the arcuate projections within their f~ssociated grooves, and secondly, there is a crescent-shaped gap indicated at C between the outer periphery of the pipes and the respective cou?ling 'member halves, which will resnlt ;n incomplete seating of the inner periphery of the coupling member halves on the outer periphery of the pipe, and, will resu]t in the compressive stress exerted on the gasket member being of progressively decreasing intensity from the mid-point of the respective coupling members towards the ends thereof. This will or can result in , incomplete sealing of the pipes by the coupling, with consequential seepage axially of the outer periphery of the pipe, and, in the case where split gaskets are employed, also can result in seepage at the radial interface of 5-the respective gasket members. ~' These problerns are obviated in their entirety according to the Ir present application, by arranging for the end faces 16a of the respective bolting pads 16 to be spaced from each other prior to and during torquing of the bolts, with the results which will now be discllssed with reference to I~igur e SB.
Upon torquing of the bolts, the respective coupling member halves, which already are in line engagelnent with the outer surface of the pipe at a point mid~'way between their ends, will exert a radially inward force on the pipes at those positions, and will stress the pipes causing'them to deform from a truly circular transverse cross-section to a transverse cross-section which is substantially elliptical, the major axis of the ellipse lying in a plane coincident ~vith or parallel to the respective planes A1 and ~2 of the ends faces of 16a ot` the respective bolting pads.
In distorting or deforming to sustantially elliptical configuration, the radius R1 along the major axis of the ellipse wiU
progressively increase, and, the radius R2 along the minor axis will pro~ressively decrease, thus forcing the entire outer periphery of the pipes into intimate seating engagemellt witll the inner periphery of the coupling .
members 14, and~ thus forcing the arcuate pr~jections 25 into full seating engagement within their associated grooves 24. Further, as the bolts are progressively torqued the pipes will progressively qssume a shape in ~hich they are in continuous engagement wit]l the gas!~et, and, in which the ~i compressive stresses in the gasl;et are equalized throughout the entire ~
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circumference thereof. In this w~y, the problem of seepage either axially of the outer periphery of the pipes, or rad;ally through the interface of the gasket members where a split gasket is employed, is elirninated in its entirety.
It ~ill be appreciated that in finally assembled condition of the coupling, the transverse cross-section of the respective pipes wil~ deviate slightly from an elliptical condition, the cross-section being theoretically that of two overlapping semicircular segments which intersect eacn other at the plane of the respective bolting pads, which, at that time are coincident with the centroid B of the pipes. The original longitudinal axis o~^ generation B of the respective coupling member halves now lie above and below the centre of the pipes as shown in Figure 6.
~ or pipes of a wall thickness intermediate the minimal wall thickness illustrated in Figures 5A, 5B and 6 and the maximum wall thickness illustrated in Figures 3 and 4, continuous engagement of the outer sllrface of the pipes with both the coupling member halves and the gasket member will occur and full seating and sealing will;be obtalned, the sole difference ~:
being that, with a progressive increase in wall thickness of the pipes, a pro"ressively increasing gap will occur between the respectiYe pairs of end faces 16A of the bolting pads 16.
The advantages accruing from ;the present invention stem from determined dimensional relationships bet~veen the coupling members and the range of wall thickness of the pipes to be accommodated by said coupllng members.
As will be~ readily apparent, in order to obtnin continuous seating of the coupling member halves relati~rely to a pipe having maximum wall thickness, then, the radius of the inner periphery of the respective .
coupling members must be identical with the `radius of the outer surface ~r of the periphery of the pipe.
If one assumes a range of pipes having the same internal .
diameter D, and having a minimum thickness T1 and a maximum thickness i~
T2, then, the radius R of the inner periphery of the respective coupling ~?-member halves must be D +22 ~T2) ~ n the other hand, in order to accommodate pipes of a wall thickness at the minimum end of the range, the combined lengths of the inner periphery of the coupling member halves must not be more than the -,~
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length of the circumference of the outer surface of such pipes of minimum wall thickness. This relationship can be expressed as ~ (D ~ 2T1) .
This relationship is critical, in that if the combined lengths of the inner peripheral walls of the coupling members is greflter than the 'length of the circumference of the exterior surface of a pipe minimum wall thickness, then, the end faces 16a will engage each other prematurely and prevent further elliptical deformation of the pipe prior to reachinb the required seating and sealing of the external periphery of the pipe relatively to the clamping members and the gasket.
While there has been described a coupling comprised by coupling member halves, it will be fuliy appreciated that for certain applications the' coupling members could be comprised by more than two f-coupling members, for example, three coupling members with the bolting pads arranged in Y arrangement. Provided that each such coupling rnernber is formed with its inner periphery of a radius identical with the radius of i the outer surface of a pipe of ma~cimum wall thickness, and, provided that the combined len~ths of the inner periphery of the respective coupling members does not exceed the circumfercntial length of the outside surface of a pipe of mininum wall thickness, then, exactly the same desirable conditions will be obtained as those discussed above with respect to a two-part coupling. The only difference will be that the cross-section of ~
the tube will be deformed or displaced into three segments instead of two, ~c' each of which will seat fully on the inner periphery of the assembled coupling, with full engagement of the arcuate projections ~5 within the grooves 24, full engagernent of the respective coupling members with the outer periphery of the pipes, and, full seating of the contained gasket mernber with the outer periphery of the pipes and equalization of the compressive stresses e~erted on the gasket member.
It will be appreciated that the structures illustrated in the `
drawings are by way of example only, and, that various modifications may be made within the scope of the invention as defined by the appended claims.
ln par~iculflr, while the invention has been described in relationship to thin-walled pipes which have been provided with radially outwardly extending arc~late projections, the coupling could also be used Witil plain' ended pipes devoid of such arcuate projections in those situations -where relative axial movement between the pipes cannot occur Optionally, ~ ~,t3~33 jl elamping ja~Ys having ineisor teeth eould be ineorporated into the grooves of the coupling members, or, the coupling members themselves eould be formed with incisor teeth to provide nn fldditional grip on plain-ended pipes.
Alternatively, the pipes could be inwardly dimpled at cireumferentially spaced positions and tile eoupling rnembers provided with corresponding dogs or teeth for entry into sueh dimples, the major consideration being that the formation of the pipes ~ith either arcuate radially outwardly extending projections or arcuAte radially inwarding extending dimples shall not interîere materially with the eapability of the pipes to distort or deform from their truly eireular eondition to a eondition of plural or multiple segments each having an outer radius whieh is that of the radius of the outer surface of a pipe having maximum wall thiekness.
Further, while the invention has been described with reference to a double-ended coupling for conneeting the adjacent ends of a pair of pipes to each other, the invention has equal applieation in a flanged, single-ended coupling employed for conneeting a pipe end to an adjacent structure.
Figure 7 illustrates such a flan~ed coupling, the coupling ineorporating all of the design parameters set out above with respect to the coupling of Figures I through 6, the major differences being in the adaptation of the coupling of Figures 1 through 6 to the form of a flanged coupling.
In Figure 7, the eoupling member, indicated generally at 30, is shown applied to the end of a pipe 31 having spaced radially extending arcuate projections 32 adjacent the free end thereof.
In an identical manner to that described above Yith reference to the coupling of Figures 1 through 6, the flanged eoupling 30 of Figure 7 ineludes coupling member halves 33 and 34 having radially extending bolting pads 35 and 36, which are secured to each other by bolts 37 and torqueing nuts 38, as previously described, in clamping engagement with the exterior surface of the pipe 31.
Each of the coupling member halves 33 and 3-1 includes a groove 39 for the reception of radially extending arcuate projections 32 formed adjflcent the end of the pipe 31, again, in the same manner as that discussed above with r espeet to Figures 1 through 6, and, each of the coupling mem~cr hnlves 33 and 34 includes a recess 4~ in which is received a gas~et mernber 41 ~hich is formed from any suitable elastomeric mate, ial.
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The respective coupling member halves each include a radially extending flange 42 having bolt holes 43 at circumferentially spaced !~
positions, whereby the flanges may be attached to an adjacent structllre having a planar face, or, whereby the flanges may be attached to the flanges of a similar or identical coupling attached to the end of another pipe, the said other pipe either being identical in dimensions with the pipe 31, or1 differing therefrom in respect of its internal radius or wall thickness. .
Conveniently, and as illustrated, the bolting pads 35 are provided with a rectangular key 35A which is received ~rithin a rectangular ~
keyway 36a in the bolting pads 36. The provisions of the key and keyway ':r acts to stabilize the respective coupling member halves on the end of the pipe during the assembly of the coupling onto the pipe end, and, further acts to ensure that the planar end faces of the coupling mernber halves are brought into co-planar relatio1lship with each other prior to the ~langes being at tached to the said adjacent structure.
In order not to interfere with the design parameters of the coupling, the keys 35a nre of a height no greater than the depth of the keyways 36a, the keys 35a preferably being of lesser height than the depth , of the keyways 36a. Additionally, the bolt holes 43 either are formed oversized in relationship to the bolts which extend therethrough, or, they are for~ed elongate in a direction radially of the longitudinal axis o~ the pipe and coupling. In this way, radially outward or radially inward movernents of the coupling member halves which are required in order to accomodate pipes of different wall thicl<ness can be accomodated without the necessity of repositioning the bolt holes in the structure to ~hich the cou?ling and pipe is to be attached.
Referring now to Figure 8, which illustrates in greater detail the gasket employed in the embodiment of Figure 7, the gasket includes a generally axially extending lip seal 41a for engagement with the outer periphery of the pipe, and includes a generally r adially extending lip seal ;
41b for sealing engagernent t^~ith the said adjacerlt structure to which the coupling is attached. r~
Conveniently, and as illustrated in Figure 8, instead of being r~
contained within a substantially continuous retainer or extrusion shield as described with reference to Figures 1 through 6, e~trusion shields ~4 are provided as an integral part of the gasket 41J the extrusion shields 44 being , l393 placed in 1I mold prior to the molding of the gasket, and thus being locsted in situ in the finished gasket. The provision of the extrusion shields 44 as an integral part of the gasket greAtly facilitates hnndl}ng of the gasket at the point of assembly at the coupling, and, eliminates the requirement for a separate extrusion shield or retainer. In use, the gasket is placed on the end oî the pipe, and, is then rotated to a position at which it will span the adjacent ends of the respective coupling member halves, subsequent to which the bolts are torqued down to fully assemble the coupling onto the pipe end.
Referring now to Figure 9, the same modification as is discussed above with respect to Figure 8 is shown as applied to the sealing gasket 21 of Figures 1 through 6. In Figure 9, respective segments 22a of the retainer are located at diametrically opposed positions within the mold employed for forming the sealing gasket 21, and thus become an integral part of the gasket during the molding process.
Preferably, the respective retainer segments 22a and 44 are either formed for them to be reflective, or, are formed or otherwise colored for them to be clearly distinguishable from the body of the sealing gasket 21. By so doing, the positlon of the retainers easily can be observed by an operative assembly the coupling, who will be given a visual indication that the retainers are correctly positioned relatively to the adjacent faces ~ .~
of the resRective pairs of bolting pads, in the manner indicated in chain- ;
dotted lines in Figure 7.
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Claims (10)
1. A quick-connect coupling for thin-walled pipes of resiliently deformable cross-section, said coupling comprising:
plural arcuate coupling members each having a medial internal groove for the reception of an elastomeric gasket;
a radially outwardly extending pad at each circumfer-ential end of each said coupling member, each said radially extending pad being adapted to receive securing means for securing said coupling members to each other in clamping engagement with said pipes;
each said radially extending pad having an end face which, in the assembled condition of the coupling, is spaced from and extends substantially parallel to a plane which includes the central longitudinal axis of said coupling member and which lies beyond the associated end of said coupling member; and, internal grooves at each axial end of said coupling members for the reception of arcuate projections on the outer periphery of the respective pipes.
plural arcuate coupling members each having a medial internal groove for the reception of an elastomeric gasket;
a radially outwardly extending pad at each circumfer-ential end of each said coupling member, each said radially extending pad being adapted to receive securing means for securing said coupling members to each other in clamping engagement with said pipes;
each said radially extending pad having an end face which, in the assembled condition of the coupling, is spaced from and extends substantially parallel to a plane which includes the central longitudinal axis of said coupling member and which lies beyond the associated end of said coupling member; and, internal grooves at each axial end of said coupling members for the reception of arcuate projections on the outer periphery of the respective pipes.
2. A quick-connect coupling as claimed in claim 1 for use with thin-walled pipe the thickness of the wall thereof falls within the range of a minimum thickness T1 and a maximum thickness T2, in which the curvature of the inner peripheral wall of the coupling member is of a radius, , where D in the internal diameter of the pipe, and, the combined lengths of the inner peripheral walls of all the coupling members comprising said coupling is not more than .pi.(D +2T1).
3. The quick-connect coupling of claim 1, further comprising arcuate coupling member halves constituting said coupling members each having an internal groove for the reception of an elastomeric gasket; said radially extended pads of each said coupling member half having end faces which lie generally in a single plane which is spaced from the central axis of said coupling member, said axis lying on that side of said plane which is opposite to the side facing said coupling member half.
4. The quick-connect coupling according to claim 3 further comprising grooves at each axial end of said coupling member halves for the reception of arcuate projections on the outer periphery of the respective pipes.
5. A quick-connect coupling for thin-walled pipes of resiliently deformable cross-section, said coupling comprising:
plural arcuate coupling members each having an internal groove;
an elastomeric gasket member positioned within said groove;
a radially outwardly extending pad at each circumfer-ential end of each said coupling member;
means securing respective adjacently positioned pairs of pads to each other and securing said coupling members in clamping engagement with said pipes;
each said radially extended pad having an end face spaced from and extending substantially parallel to a plane including the central longitudinal axis of said coupling member and which lies beyond the associated end of said coupling member; and, grooves at each axial end of said coupling members for the reception of arcuate projections on the outer periphery of the respective pipes.
plural arcuate coupling members each having an internal groove;
an elastomeric gasket member positioned within said groove;
a radially outwardly extending pad at each circumfer-ential end of each said coupling member;
means securing respective adjacently positioned pairs of pads to each other and securing said coupling members in clamping engagement with said pipes;
each said radially extended pad having an end face spaced from and extending substantially parallel to a plane including the central longitudinal axis of said coupling member and which lies beyond the associated end of said coupling member; and, grooves at each axial end of said coupling members for the reception of arcuate projections on the outer periphery of the respective pipes.
6. The quick-connect coupling of claim 5, further comprising a rigid retainer surrounding said elastomeric gasket member and which spans any existing gap between each adjacent pair of end faces of said radially outwardly extending pads.
7. A quick-connect coupling as claimed in claim 5 for use with thin-walled pipe the thickness of the wall thereof falls within the range of a minimum thickness T1 and a maximum thickness T2, in which the curvature of the inner peripheral wall of the coupling member is of a radius, , where D in the internal diameter of the pipe, and, the combined lengths of the inner peripheral walls of all of the coupling members comprising said coupling is not more than .pi.(D + 2T1).
8. A quick-connect coupling for thin-walled pipes of resiliently deformable cross-section, said coupling comprising:
arcuate coupling member halves, each having an internal groove;
an elastomeric gasket member received within said internal groove;
a radially outwardly extending pad at each circumfer-ential end of said coupling member half;
securing means securing adjacent radially extending pads to each other and securing said coupling members in clamping engagement with said pipes;
said radially extending pads of each coupling member half having end faces which lie generally in a single plane which is spaced from the central axis of said coupling member half, said axis lying on that side of said plane which is opposite to the side of said plane facing said coupling member half; and grooves at each axial end of said coupling member halves for the reception of arcuate projections on the outer periphery of the respective pipes.
arcuate coupling member halves, each having an internal groove;
an elastomeric gasket member received within said internal groove;
a radially outwardly extending pad at each circumfer-ential end of said coupling member half;
securing means securing adjacent radially extending pads to each other and securing said coupling members in clamping engagement with said pipes;
said radially extending pads of each coupling member half having end faces which lie generally in a single plane which is spaced from the central axis of said coupling member half, said axis lying on that side of said plane which is opposite to the side of said plane facing said coupling member half; and grooves at each axial end of said coupling member halves for the reception of arcuate projections on the outer periphery of the respective pipes.
9. The quick-connect coupling of claim 8, further comprising a rigid retainer surrounding said elastomeric gasket member and which spans any existing gap between each adjacent pair of end faces of said radially outwardly extending pads.
10. A quick-connect coupling as claimed in claim 8 for use with thin-walled pipe the thickness of the wall thereof falls within the range of a minimum thickness T1 and a maximum thickness T2, in which the curvature of the inner peripheral wall of the coupling member is of a radius, , where D in the internal diameter of the pipe, and, the combined lengths of the inner peripheral walls of all of the coupling members comprising said coupling is not more than .pi.(D + 2T1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000434062A CA1179393A (en) | 1983-08-08 | 1983-08-08 | Quick-connect coupling for thin-walled pipes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000434062A CA1179393A (en) | 1983-08-08 | 1983-08-08 | Quick-connect coupling for thin-walled pipes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1179393A true CA1179393A (en) | 1984-12-11 |
Family
ID=4125817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000434062A Expired CA1179393A (en) | 1983-08-08 | 1983-08-08 | Quick-connect coupling for thin-walled pipes |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1179393A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2011200087B2 (en) * | 2004-05-14 | 2012-08-16 | Victaulic Company | Deformable mechanical pipe coupling |
-
1983
- 1983-08-08 CA CA000434062A patent/CA1179393A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2011200087B2 (en) * | 2004-05-14 | 2012-08-16 | Victaulic Company | Deformable mechanical pipe coupling |
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| MKEC | Expiry (correction) | ||
| MKEX | Expiry |