GB2049853A - Pipe couplings - Google Patents

Pipe couplings Download PDF

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Publication number
GB2049853A
GB2049853A GB7917943A GB7917943A GB2049853A GB 2049853 A GB2049853 A GB 2049853A GB 7917943 A GB7917943 A GB 7917943A GB 7917943 A GB7917943 A GB 7917943A GB 2049853 A GB2049853 A GB 2049853A
Authority
GB
United Kingdom
Prior art keywords
pipe
ferrule
leading end
pipe coupling
tapering
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.)
Granted
Application number
GB7917943A
Other versions
GB2049853B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
James Neill Holdings Ltd
Original Assignee
James Neill Holdings Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by James Neill Holdings Ltd filed Critical James Neill Holdings Ltd
Priority to GB7917943A priority Critical patent/GB2049853B/en
Priority to ZA00802688A priority patent/ZA802688B/en
Priority to AU58128/80A priority patent/AU5812880A/en
Priority to DE19803018444 priority patent/DE3018444A1/en
Priority to FI801613A priority patent/FI801613A/en
Priority to SE8003741A priority patent/SE8003741L/en
Priority to DK219980A priority patent/DK219980A/en
Priority to NO801524A priority patent/NO801524L/en
Priority to JP6796480A priority patent/JPS55159392A/en
Publication of GB2049853A publication Critical patent/GB2049853A/en
Application granted granted Critical
Publication of GB2049853B publication Critical patent/GB2049853B/en
Expired legal-status Critical Current

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
    • F16L19/00—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts
    • F16L19/08—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts with metal rings which bite into the wall of the pipe
    • F16L19/10—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts with metal rings which bite into the wall of the pipe the profile of the ring being altered
    • F16L19/106—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts with metal rings which bite into the wall of the pipe the profile of the ring being altered the ring comprising a shoulder against which the pipe end abuts
    • 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
    • F16L19/00—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts
    • F16L19/08—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts with metal rings which bite into the wall of the pipe
    • F16L19/10—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts with metal rings which bite into the wall of the pipe the profile of the ring being altered
    • F16L19/103—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts with metal rings which bite into the wall of the pipe the profile of the ring being altered with more than one ring per pipe end being used

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Joints With Pressure Members (AREA)
  • Pulleys (AREA)
  • Mechanical Operated Clutches (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

A pipe coupling of the type comprising a body member A, a nut member B screwing onto the body member A, and front and rear ferrules C, D for mounting on a pipe between the body and nut members, has a convexly tapering leading end 5 of the front ferrule C contacting a straight tapered converging wall 2 in the body member A, a convexly tapering leading end 7 of the rear ferrule D contacting a straight tapered mouth 6 in the trailing end of the front ferrule C, and a convexly tapering trailing end 8 of the rear ferrule D contacting a straight bevel 9 in the inner end of the nut member. The angle of the converging wall 2 in the body member is between 12 DEG and 20 DEG to the axis, preferably 15 DEG , the angle of the tapering mouth 6 in the front ferrule is 45 DEG to the axis, and the angle of the bevel 9 in the nut member is between 75 DEG and 80 DEG to the axis, preferably 77 DEG . The front ferrule is thickened around the tapering mouth, being stepped up from the larger end of the leading end, which curves to a flat annular front end face the inner edge of which bites into an inserted pipe. The rear ferrule is stepped up between the larger end of the leading end and the larger end of the trailing end, and the leading end curves to an edge which bites into an inserted pipe. <IMAGE>

Description

SPECIFICATION Pipe couplings This invention relates to pipe couplings of the type comprising a body member having an external screw-thread and an axially-disposed internal wall converging towards a bore for receiving an end of a pipe to be secured in the coupling, a nut member for mounting on a pipe and having a screw-thread fitting the screwthread on the body member, and front and rear deformable ferrules for mounting on a pipe between the body and nut members, the front ferrule having an externally tapered leading end for contacting the converging wall in the body member and an inwardly tapering mouth at the trailing end, the rear ferrule having an externally tapered leading end for contacting the tapered mouth of the front ferrule and an externally tapered trailing end, and the nut member having an annular bevel at the inner end of the screwthread for contacting the trailing end of the rear ferrule, whereby, when the body and nut members are in position around a pipe with the ferrules therebetween, screwing of the nut and body members together forces the leading end of the front ferrule into the convergent space between the converging wall in the body member and the outer surface of the pipe, and thereby compresses radially the leading end of the front ferrule so that it grips the pipe, and the leading end of the rear ferrule is forced into the tapering mouth in the trailing end of the front ferrule, and thereby compresses radially the leading end of the rear ferrule so that it too grips the pipe.The angle of the tapering mouth of the front ferrule is appreciably greater than the angle of the converging internal wall of the body member, so that the leading end of the front ferrule grips the pipe before the leading end of the rear ferrule, the rise in the effort required to tighten the nut and body members when the leading end of the rear ferrule grips the pipe being an indication that the leading end of the front ferrule is gripping the pipe sufficiently to provide a satisfactory seal of the coupling with the pipe, as well as holding the pipe against pulling out of the coupling. Such a coupling will be called hereinafter "a coupling of the type referred to".
As the leading end of the front ferrule begins to grip the pipe, friction between the front ferrule and the body member, also between the rear ferrule and the front ferrule, and between the nut member and the rear ferrule increases and continues to increase as the grip increases, and may become so appreciable by the stage at which the leading end of the rear ferrule begins to grip the pipe that the rise in the effort required to tighten the nut and body members is not substantial enough to serve as an indication that the leading end of the rear ferrule is beginning to grip the pipe.
The object of the present invention, therefore, is to reduce friction in a coupling of the type referred to.
According to the present invention, in a coupling of the type referred to the converging internal wall of the body member, the tapering mouth in the front ferrule, and the annular bevel in the nut member all have straight longitudinal profiles, while the leading end of the front ferrule, the leading end of the rear ferrule, and the trailing end of the rear ferrule all have convex longitudinal profiles such that each convexly tapering surface initially fits into its respective straight tapering surface to make line contact therewith intermediate of its ends.
Thus, there is not anywhere, between the body member and the front ferrule, between the front ferrule and the rear ferrule, or between the rear ferrule and the nut member, at any time while the nut and body members are being tightened together, any appreciable surface contact to create high friction or increase friction, nor any possibility of a circumferential edge being brought into contact with a surface. Therefore, the rise in effort required to tighten the nut and body members when the leading end of the rear ferrule grips the pipe will be significant and will, accordingly, afford a very clear indication that the leading end of the front ferrule is gripping the pipe sufficiently to provide a satisfactory seal of the coupling with the pipe, as well as holding the pipe against pulling out of the coupling.
The convexly tapering surfaces can be regarded as executing rolling sliding movement with respect to the respective straight tapering surfaces as the nut and body members are tightened.
Alternatively, the longitudinal sections of the ferrules can be regarded as rocking inwardly with respect to the axis from their trailing ends to their leading ends.
The angle of the converging internal wall of the body member is preferably between 120 and 200 to the axis, more particularly 15 , the angle of the tapering mouth in the front ferrule is preferably 450 to the axis, and the angle of the bevel in the nut member is preferably between 750 and 800 to the axis, more particularly 770.
The front ferrule preferably has a thicker portion around the tapering mouth in its trailing end, to afford increased resistance to stretching when the leading end of the rear ferrule is pushed into the tapering mouth in the front ferrule, the thicker portion preferably being stepped up from the larger end of the convexly tapering leading end, and the thicker portion preferably has a cylindrical outer surface. The leading end of the front ferrule preferably has a flat annular end face the inner edge of which is adapted to bite into the pipe. The rear ferrule preferably has a step up between the larger end of the leading end and the larger end of the trailing end, and the leading end of the rear ferrule preferably curves from the step to an edge which is adapted to bite into the pipe.The trailing end of the rear ferrule also preferably curves from the step to an edge, but this rear edge does not bite into the pipe.
The bore in the body member is preferably connected by an annular shoulder with a smaller bore, the annular shoulder serving as a stop for an inserted pipe.
A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which Figures 1 to 4 are all half-sectional side elevations of respectively a body member, a front ferrule, a rear ferrule, and a nut member that together form a pipe coupling in accordance with the invention; Figure 5 is a longitudinal section to a larger scale of one half of the coupling as initially assembled and with a pipe inserted; and Figure 6 corresponds to Figure 5 but shows the coupling when the nut and body members have been screwed together until both ferrules grip the pipe.
The pipe coupling shown in the drawings comprises a body member A, having an external screw-thread 1 and an axially disposed internal wall 2 converging towards a bore 3 for receiving an end of a pipe to be secured in the coupling, a nut member B for mounting on a pipe and having a screw-thread 4 fitting the screw-thread 1 on the body member A, and front and rear deformable ferrules C, D, respectively, for mounting on a pipe between the body and nut members, the front ferrule C having an externally tapered leading end 5 for contacting the converging wall 2 in the body member A and an inwardly tapering mouth 6 at the trailing end, the rear ferrule D having an externally tapered leading end 7 for contacting the tapering mouth of the front ferrule and an externally tapered trailing end 8, and the nut member B having an annular member B having an annular bevel 9 at the inner end of the screwthread 4 for contacting the trailing end of the rear ferrule, whereby, when the body and nut members A, B are in position around a pipe 10 (Figure 5} with the ferrules C, D, therebetween, screwing of the nut and body members together (Figure 6) forces the leading end 5 of the front ferrule C into the convergent space between the converging wall 2 in the body member A and the outer surface 11 of the pipe, and thereby compresses radially the leading end of the front ferrule so that it grips the pipe, and the leading end 7 of the rear ferrule D is forced into the tapering mouth 6 in the trailing end of the front ferrule C, and thereby compresses radially the leading end 7 of the rear ferrule so that it too grips the pipe.The angle of the tapering mouth 6 of the front ferrule C is appreciably greater than the angle of the converging internal wall 2 of the body member A, so that the leading end 5 of the front ferrule grips the pipe 10 before the leading end 7 of the rear ferrule, the rise in the effort required to tighten the nut and body members when the leading end 7 of the rear ferrule grips the pipe being an indication that the leading end 5 of the front ferrule is gripping the pipe sufficiently to provide a satisifactory seal of the coupling with the pipe, as well as holding the pipe against pulling out of the coupling.
In accordance with the invention, the converging internal wall 2 of the body member A, the tapering mouth 6 in the front ferrule C, and the annular bevel 9 in the nut member B all have straight longitudinal profiles, while the leading end 5 of the front ferrule C, the leading end 7 of the rear ferrule D, and the trailing end 8 of the rear ferrule all have convex longitudinal profiles such that each convexly tapering surface intitially fits into its respective straight tapering surface to make line contact therewith intermediate its ends.Thus, there is not anywhere, between the body member A and the front ferrule C, between the front ferrule and the rear ferrule D, or between the rear ferrule and the nut member B, at any time while the nut and body members are being tightened together, any appreciable surface contact to create high friction or increase friction, nor any possibility of a circumferential edge being brought into contact with a surface. Therefore, the rise in effort required to tighten the nut and body members A, B when the leading end 7 of the rear ferrule D grips the pipe will be significant and will, accordingly, afford a very clear indication that the leading end 5 of the front ferrule C is gripping the pipe 10 sufficiently to provide a satisfactory seal of the coupling with the pipe, as well as holding the pipe against pulling out of the coupling.
The convexly tapering surfaces 5, 7 and 8 can be regarded as executing rolling sliding movement with respect to the respective straight tapering surfaces 2, 6 and 9 as the nut and body members A, B are tightened. Alternatively, the longitudinal sections of the ferrules C, D can be regarded as rocking inwardly with respect to the axis from their trailing ends to their leading ends.
The angle of the converging internal wall 2 of the body member A is 1 50 to the axis, the angle of the tapering mouth 6 in the front ferrule C is 450 to the axis, and the angle of the bevel 9 in the nut member B is 770 to the axis.
The front ferrule C has a thicker portion 12 around the tapering mouth 6 in its trailing end, to afford increased resistance to stretching when the leading end 7 of the rear ferrule D is pushed into the tapering mouth, the thicker portion being stepped up from the larger end of the convexly tapering leading end 5, and the thicker portion having a cylindrical outer surface. The leading end 5 of the front ferrule C has a flat annular end face 13 the inner edge 14 of which is adapted to bite into the pipe 10. The rear ferrule D has a step up 15 between the larger end of the leading end 7 and the larger end of the trailing end 8, and the leading end 7 curves from the step 1 5 to an edge 16 which is adapted to bite into the pipe 10. The trailing end 8 of the rear ferrule D also curves from the step 1 5 to an edge 17, but this rear edge does not bite into the pipe.
The bore 3 in the body member A is connected by an annular shoulder 18 with a smaller bore 19 (which preferably has, as shown, the same diameter as the bore of the pipe 10), the annular shoulder serving as a stop for the inserted pipe.

Claims (13)

1. A pipe coupling comprising a body member having an external screw-thread and an axiallydisposed internal wall converging towards a bore for receiving an end of a pipe to be secured in the coupling, a nut member for mounting on a pipe and having a screw-thread fitting the screwthread on the body member, and front and rear deformable ferrules for mounting on a pipe between the body and nut members, the front ferrule having an externally tapered leading end for contacting the converging wall in the body member and an inwardly tapering mouth at the trailing end, the rear ferrule having an externally tapered leading end for contacting the tapering mouth of the front ferrule and an externally tapered trailing end, and the nut member having an annular bevel at the inner end of the screwthread for contacting the trailing end of the rear ferrule, the converging internal wall of the body member, the tapering mouth in the front ferrule, and ,he annular bevel in the nut member all having straight longitudinal profiles, while the leading end of the front ferrule, the leading end of the rear ferrule, and the trailing end of the rear ferrule, all have convex longitudinal profiles such that each convexly tapering surface initially fits into its respective straight tapering surface to make line contact therewith intermediate to its ends.
2. A pipe coupling as in Claim 1, wherein the angle of the converging internal wall of the body member is between 120 and 200 to the axis.
3. A pipe coupling as in Claim 2, wherein the angle of the converging internal wall of the body member is 1 50 to the axis.
4. A pipe coupling as in any one of the Claims 1 to 3, wherein the angle of the tapering mouth in the front ferrule is 450 to the axis.
5. A pipe coupling as in any one of Claims 1 to 4, wherein the angle of the bevel in the nut member is between 750 to 800 to the axis.
6. A pipe coupling as in Claim 5, wherein the angle of the bevel in the nut member is 770 to the axis,
7. A pipe coupling as in any one of Claims 1 to 6, wherein the front ferrule has a thicker portion around the tapering mouth in its trailing end.
8. A pipe coupling as in Claim 7, wherein the thicker portion is stepped up from the larger end of the convexly tapering leading end, and the thicker portion has a cylindrical outer surface.
9. A pipe coupling as in any one of Claims 1 to 8, wherein the leading end of the front ferrule has a flat annular end face the inner edge of which is adapted to bite into the pipe.
10. A pipe coupling as in any one of Claims 1 to 9, wherein the rear ferrule has a step up between the larger end of the leading end and larger end of the trailing end.
11. A pipe coupling as in Claim 10, wherein the leading end of the rear ferrule curves from the step to an edge which is adapted to bite into the pipe.
12. A pipe coupling as in any one of Claims 1 to 11, wherein the bore in the body member is connected by an annular shoulder with a smaller bore.
13. A pipe coupling substantially as hereinbefore described with reference to the accompanying drawings.
GB7917943A 1979-05-23 1979-05-23 Pipe couplings Expired GB2049853B (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
GB7917943A GB2049853B (en) 1979-05-23 1979-05-23 Pipe couplings
ZA00802688A ZA802688B (en) 1979-05-23 1980-05-05 Pipe couplings
AU58128/80A AU5812880A (en) 1979-05-23 1980-05-06 Pipe coupling
DE19803018444 DE3018444A1 (en) 1979-05-23 1980-05-14 PIPE COUPLING
FI801613A FI801613A (en) 1979-05-23 1980-05-19 ROERKOPPLING
SE8003741A SE8003741L (en) 1979-05-23 1980-05-20 TUBE COUPLING
DK219980A DK219980A (en) 1979-05-23 1980-05-20 CANE CONNECTION
NO801524A NO801524L (en) 1979-05-23 1980-05-22 ROER CLUTCH.
JP6796480A JPS55159392A (en) 1979-05-23 1980-05-23 Pipe joint

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7917943A GB2049853B (en) 1979-05-23 1979-05-23 Pipe couplings

Publications (2)

Publication Number Publication Date
GB2049853A true GB2049853A (en) 1980-12-31
GB2049853B GB2049853B (en) 1983-04-27

Family

ID=10505379

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7917943A Expired GB2049853B (en) 1979-05-23 1979-05-23 Pipe couplings

Country Status (9)

Country Link
JP (1) JPS55159392A (en)
AU (1) AU5812880A (en)
DE (1) DE3018444A1 (en)
DK (1) DK219980A (en)
FI (1) FI801613A (en)
GB (1) GB2049853B (en)
NO (1) NO801524L (en)
SE (1) SE8003741L (en)
ZA (1) ZA802688B (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2320304A (en) * 1996-12-13 1998-06-17 Hepworth Building Prod Pipe-fitting with inwardly cammed pipe gripping means
WO2001020214A1 (en) * 1999-09-13 2001-03-22 Swagelok Company Tube fitting with indicating means
US6279242B1 (en) 1999-09-13 2001-08-28 Swagelok Company Intrinsic gauging for tube fittings
US6640457B2 (en) 1999-09-13 2003-11-04 Swagelok Company Intrinsic gauging for tube fittings
EP1536175A3 (en) * 1999-09-13 2005-10-19 Swagelok Company Tube fitting with indicating means
US7194817B2 (en) 1999-09-13 2007-03-27 Swagelok Company Intrinsic gauging for tube fittings
US7240929B2 (en) 1997-04-15 2007-07-10 Swagelok Company Ferrule with plural inner diameters
US10100955B2 (en) 1997-04-15 2018-10-16 Swagelok Company Advanced geomerty ferrule

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10215315B2 (en) 2008-09-05 2019-02-26 Parker-Hannifin Corporation Tube compression fitting and flared fitting used with connection body and method of making same
JP6283640B2 (en) * 2015-09-30 2018-02-21 因幡電機産業株式会社 Pipe fitting

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2320304B (en) * 1996-12-13 2001-05-16 Hepworth Building Prod Pipe-fitting
GB2320304A (en) * 1996-12-13 1998-06-17 Hepworth Building Prod Pipe-fitting with inwardly cammed pipe gripping means
US7240929B2 (en) 1997-04-15 2007-07-10 Swagelok Company Ferrule with plural inner diameters
USD884130S1 (en) 1997-04-15 2020-05-12 Swagelok Company Back ferrule
US10100955B2 (en) 1997-04-15 2018-10-16 Swagelok Company Advanced geomerty ferrule
US7367595B2 (en) 1997-04-15 2008-05-06 Swagelok Company Ferrule having convex interior wall portion
US6279242B1 (en) 1999-09-13 2001-08-28 Swagelok Company Intrinsic gauging for tube fittings
EP1536175A3 (en) * 1999-09-13 2005-10-19 Swagelok Company Tube fitting with indicating means
US7194817B2 (en) 1999-09-13 2007-03-27 Swagelok Company Intrinsic gauging for tube fittings
US6941668B2 (en) 1999-09-13 2005-09-13 Swagelok Company Intrinsic gauging for tube fittings
US6640457B2 (en) 1999-09-13 2003-11-04 Swagelok Company Intrinsic gauging for tube fittings
US6502323B2 (en) 1999-09-13 2003-01-07 Swagelok Company Intrinsic gauging for tube fittings
WO2001020214A1 (en) * 1999-09-13 2001-03-22 Swagelok Company Tube fitting with indicating means
US7430811B2 (en) 2003-03-12 2008-10-07 Swagelok Company Intrinsic gauging for tube fittings

Also Published As

Publication number Publication date
ZA802688B (en) 1981-05-27
GB2049853B (en) 1983-04-27
DK219980A (en) 1980-11-24
NO801524L (en) 1980-11-24
JPS55159392A (en) 1980-12-11
DE3018444A1 (en) 1980-12-04
SE8003741L (en) 1980-11-24
AU5812880A (en) 1980-11-27
FI801613A (en) 1980-11-24

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee