CA2223976A1

CA2223976A1 - Pipe connection

Info

Publication number: CA2223976A1
Application number: CA002223976A
Authority: CA
Inventors: Park Sil Sang
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-01-01
Filing date: 1998-02-16
Publication date: 1999-08-16
Also published as: JPH11230439A; ES2160438B1; GB9803267D0; NL1008375C2; AU693065B1; ZA981411B; GB2334316A; ES2160438A1

Abstract

A pipe connection, device comprising a reentrant groove near the end of the pipe and pressure projections which bear on the outer surface of a narrow inner rind so as to force the end of the ring into the reentrant groove leakage and greater structural strength to tension on the pipe.
The reentrant groove is positioned to be exactly within the end of the ductile ring within the connection device. The tightening nut on the pipe connection device also has pressure projections on the inner surface bearing against the outside of the ductile rind. This reduces friction on the pipe and thus allows easier tightening and greater pressure to be applied to force a salient of the ductile ring into the reentrant groove. ~
Alternative embodiments disclose pressure projections on the ductile rind, a two pan ductile ring, and a ductile ring capable of reducing its circumference as it is tightened.
Also disclosed are devices for making the reentrant groove near the end of the pipe.

Description

TITLE OF THE INVENTION
Pipe Connection FIELD OF THE INVENTION
The present invention, relates to pipe connections. More specifically, the invention relates to a pipe connecting device which has a reentrant groove near the end of one of the pipes to be connected, such that a ductfie ring within the connection is forced into the reentrant groove so as to provide a better connection between the connection and the pipe.
The pipe connection has pressure projections on the interior surface of the tightening nut, so as to reduce friction and allow greater pressure to be applied to drive the ductile ring into the reentrant ~oove.
BACI~GROL'ND OF THE INVENTION
Known pipe connections have been adapted to allow insertion of one end of a pipe into the connection, where the ducule ring s3ides over the outside of the pipe end.
The exterior of the connection is formed to be a tightening nut, turning it puts pressure on the ductile ring within, clamping the ductile ring tightly over the pipe end.
However, the known system has a large surface area of contact between the interior surface of the tightening nut and the exterior surface of the ductile ring.
This increases friction as the tightening nut is being turned to put pressure on the ductile ring within it. The increased friction means decreased e~ciency of clamping, resulting in greater di,~ficulty of installation and reduced pressure on the ductrle ring. The lower pressure on the ducnle ring in turn means that the connection is not as firm and leak proof as it might otherwise be. Worse, the increased chance of leakage presented by this problem is not 11'kely to manifest itself until a considerable period of time has elapsed after completion of the coupling.
Finally. the ductile ring and the pipe end have only a simple toroidal contact between the interior of the ductile ring and the exterior of the pipe end. In the lr'kely event of later tension forces on the pipes, the connection is a weak point which is likely to move or warp under the tension force. The result is likelihood of leakage.
There exists, therefore, a need to overcome the above problems of the conventional pipe connection.
OBJECTS OF THE INVENTION
It is therefore one object of the present invention to provide a pipe connection which maintains a tighter connection between the pipe connection and the pipe end.
It is another object of the present invention to provide a pipe connection which is less prone to leakage long after installation.
It is another object of the present invention to provide a pipe connection which is capable of maintaining a tight. leak-proof seal despite external tensions which would tend to warp the pipe connecrion.
It is another object of the present invention to provide a pipe connexion which reduces the friction of the tightening, making it easier to tighten the nut.

S L~L~RY O F THE f~'Z'E1 TI O N
The invention consi.ss of a reentrant ~oove on the pipe arranffed at a predetermined distance W from the end of the pine acted upon by an improved tightening nut which applies su.~cient preswure to the ductile zing of the connector to drive the lip of the ductile rind into the reentrant groove. Tne improvement in the nut consists of pressure proje~ions on the interior surface nut squeezes the outer surface of the ductile zing to force the extreme end of the duczi3e ring into the reentrant groove.
The increased pressure applied by the improved tightening nut is itself an asset in preventing leakage at the connection and in maintaining a strong connection asainst future leakase.
y The salient of the ductile ring which projects into the reentrant groove provides greatly increased strength to the connection of the pipes. Especially, remaining stronger under conditions of tension (such as support of a weight) increases protection against leaks, which is most useful long after the pipes have been installed.
The reduced fizction of the tightening nut also aids installation of the pipe connection, thus reducing time, energy and cost of the pipe connection.
Other objects and aspects of the invention will become apparent from the following descriptions and by reference to the drawings of the invention.
BRIEF DESCRIPTION'OF THE DRAWINGS
Figure 1 is an exploded perspec 'rn-e view illustrating construction of a pipe connection according to the present invention;
Figure 2 is a partially cut sectional view z~Iustrating a pipe connected by means of the invention as shown in Figure 1;
Figure 3 is a sectional view taken along line C-C of Figure 2;
Figure ~ is an exploded perspective view z7lustrating an alternative embodiment in a pipe connector having a different type of ducule ring;
Figure ~ is a partially cut sectional viemllustratmg a pipe connected by means of the invention as shown in Figure 4;
Figure 6 is a perspective view of an alternative embodiment in which pressure projections are built on the ductile ring rather than on the tightening nut;
Figure 7 is a sectional view z7lustrating a tightening nut constructed according to the invention as shown in Figure 1;
Figure 8 is a sectional view of an alternative embodiment of the invention having pressure projections at an angle to the axis of the connection;
Figure 9 is an exploded perspective view of an akernative embodiment having pressure projections on the connector rather than the tightening nut;
Figure 10 is a partially cut sectional view 1'Ilustrating one embodiment of a working tool for the invention;
Figure 11 is a partially cut sectional view illustrating an alternative embodiment of a working tool for the invention;
Figure 1? is a partially cut sectional view illustrating an alternative embodiment adapted for a folding type pipe:
Figure 13 is a perspective view illustrating another embodiment having two ductile rings;
Figure 1~ is an exploded perspec 'rn~e view illustrating still another embodiment relating to the ductile rng embodiment of Figure I
Figure I : is a cross sectional vew illustrating an application of the ductile rind emboaiment of Fig~.we I ~ :.
Fisure I6 is perspective view illusratinQ a ductile ring with pressure projections upon it:
Figure 1 i is a perspective view illustrating an alternative embodiment relating to the embodiment pictured in Fisure 16; and Figure 18 is a sectional view illustrating an application of the embodiment of Figure 16.
DETAILED DESCRIPTION OF THE PREFERRED E1~ODIMENT
The best mode or preferred embodiment are shown in Figure 1. Figure 1 is an exploded perspective view l7hzstrating construction of a pipe connection according to the present invention. As shown in Fire 1, copper pipe ends A and B are connected by the invention. Body screw 1 has pipe end encounter threads 2 and engaging threads 3, as well as ductile ring ~. Ductile ring 4 is a thin ring of material which may be pan of the body screw 1, as shown in this embodiment, or may be a separate component, as shown in an alternative embodiment illustrated below. Ductile ring :I possesses su~cient ductility to deform slightly when e~aernal pressure is applied, and may have a variety of cross sections, as will be illustrated is late embodiments. In this embodiment, ductile ring 4 possesses a thin lip 4a to allow greater ductility at that point, and is a protrusion of body screw I. In other arrangements of the invention, the entire ductile ring 4, or other sections of ductile ring 4 might be thin, or otherwise made especially ductile.
Tightening nut ~ has a screw portion 6 which couples with the engaging threads 3 of the body screw 1. Tightening nut ~ also has an inclined surface 7 to match the external surface 4b of ductile ring ~. Disposed upon the inclined surface 7 are a plurality of pressure projections 8. The pressure projections 8 bear upon the external surface 4b of ductile ring 4, applying increasing pressure to it as tightening nut 5 is screwed onto body screw 1, but not allowing the entire inclined surface 7 to contact ductile ring 4 until ductile ring 4 is deformed in the final stages of engaging tightening nut ~. In known systems, the large contact area between the interior of tightening nut 5 and the exterior of ductile sing 4 increases friction, making tightening more di~cult. A packing ring 10 is disposed within ductile ring 4 in this embodiment_ Reentrant groove 11 is a groove on the exterior of pipe end A, disposed at a distance W from the end of pipe end A Reentrant groove 11, in this embodiment, spans the thin lip 4a of ductile ring 4 such that as the tightening ring ~ is screwed onto body screw l, pressure projections 8 bear upon ductile ring 4, forcing a salient of ductile ring 4, in this embodiment, the thin lip 4a, to enter the reentrant groove. This locks the two pipe ends A
and B together, malting them better able to withstand tensional forces.
Figure 2 is a partially cut sectional view illustrating a pipe connected by means of the invention as shown in Figure 1,~ A thin lip 4a of ductile ring 4 is shown pressed into reentrant groove 11.
Figure 3 is a sectional view taken along line C-C of Figure 2; showing pressure projections 8 bearing on the exterior surface 4b of ductile ring 4, and maintaining a slight separation between the interior of tightening nut ~ and the exterior of ductile ring 4.
Figure =~ is an exploded perspective vew illustratinj an alternative embodiment in a pipe connector having a different type of ductile ring 12; the ductile ring 12 in this embodiment is a separate object from the body screw 1. In this embodiment, pressure projections 8 are disposed within the interior surface ofbody screw 1.
Otherwise, this embodiment is not ~~incantly differ ent from the previous one. Note that ti~teninQ screw ~
does not have pressure projections in this embodiment, but clearly could.
Figure ~ is a partially cut sectional view illustrating a pipe conne~ ed by means of the invention as shown in Figure 4, showing a salient of ductile ring 12 forced into the reentrant ~oove 11.
Figure 6 is a perspective view of an alternative embodiment in which pressure projections 8 are built on the ductile ring 12 rather than on the tightening nut.
Fisure 7 is a sectional view illustrating a tightening nut constructed according to the invention as shown in Figure 1.
Figure 8 is a sectional view of an alternative embodiment of the invention having pressure projections 8 at an angle to the axis of the connection.
Figure 9 is an exploded perspective view of an alternative embodiment having pressure projections 8 on the body screw 1 rather than the tightening nut ~. In this embodiment, the body screw 1 of the invention also has a core pipe 1 a.
Figure 10 is a partially cut sectional view illustrating one embodiment of a working tool 13 for the invention; the working tool 13 has a roller cutter 13a and a molding roller 13b separated from each other by the predetermined distance W. As the working tool 13 is rotated over a pipe work piece, the roller cutter 13a cuts the pipe whale the molding roller lib forms the reentrant groove 11.
Figure I 1 is a partially cut sectional view illustrating an alternative embodiment of a working tool I3 for the invention; capable of putting the reentrant groove 11 on both sides of a pipe work piece.
Figure 12 is a partially cut sectional view illustrating an alternative embodiment adapted for a folding or spiral type pipe.
Figure 13 is a perspective view illustrating another embodiment of the invention. In this embodiment, ductile ring 12 has a locking projection 12 d which fits within reentrant groove 11 when the invention is installed. Duct~e ring 12 also has a small nap 12b. Note that ductile ring 12 also has a di$'erent cross section, one with a thinner projecting portion which is used in conjunction with packing ring 10 to provide a better seal.
Figure 14, shows a similar embodiment, in which the ductMe ring 12 is mated to a second ring 12a, which fits within ductile ring 12 to provide a tighter closure after installation of the invention. The two rings fit together to foam a single unit. Ductile ring 12 also has a narro connection 12c across the small nap 12b. When ductile ring 12 is used with a tightening nut ~ such as was shown in Figure 1, having pressure projections 8 on the interior, the narrow connection 12c acts to slide the pressure projections 8 across the small gap 12b, preventing the two units from locking together.
In this embodiment, when the tightening nut ~ is su~cieatiy tight, the narrow connection 12c breaks, narrowing the small gap 12b and providing a tighter seal The small nap 12b may be a narrowing of said ductile ling, as shown in Figure 14 or at least one hole leaving a plurality of narrow connections 12c, or it may span the entire ductzZe ring, leaving no narrow connection 12c.
Note that in this embodiment, the packing seal 10 and the second ring 12a act cooperate to form a tight closure. In this embodiment, packing seal 10 is designed to have a large width, so as to cover the surfaces of second rind 12a. This embodiment has the advantage of being usable on existing pipe connections without modification or change.
Figure 1 ~ is a cross sectional view illustrating an application of the ductile rind embodiment of Figure 13, and showing how the packing seal I O and the second ring 12a portion of the ductile rins 12 act toeether to form a tight szal_ Fi~,ire 16 is perspective vew illusratinQ an aite:native embodiment of the invention haling an adaitional cir~,imferential pres~-ure projection 8a on the external surface -~b of ductile rns t. This acts to reduce friction by reducing the amount of surface contact area.
Figure 1 i is a perspec 'rn~e view illustratinff an alteznative embodiment relating to the embodiment pictured in Fi~.ire 16; in which the circumferential pressure proje~ ions 8b are not circumferentiallv continuous.
Figure 18 is a sectional view ~ustratin~ an application of the embodiment of Fi_sure 16.
The circumferential pressure projections 8a and 8b could be, as shown, on the duct~e rind 4, or on ductile rind 12, or on the inclined surface 7 of tightenin5 nut ~, without exceeding the scope of the invention.
The above descriptions enable one skilled in the art to practice the invention in the best mode presently known, however, many variations, alternatives and equivalents will be obvious to one skilled in the art W thout departing tom the scope of the invention.
The above descziptions do not limit the scope of the invention in any way; the invention' s scope is defined only by the claims following.

Claims

1. a pipe connection having first and second pipe ends to be connected, comprising:
a tightening nut coaxially connected to the exterior of said first pipe end so as to rotate;
a body screw coaxially affixed to said second pipe end; wherein said tightening nut operantly enrages said body screw;
a ductile ring disposed within said tightening nut so as to encase said first pipe end when said body screw is engaged;
a circumferential reentrant groove on the exterior surface of said first pipe end, situated at a distance from the end of said first pipe end such that when said tightening screw is engaged, said circumferential reentrant groove is encased within said ductile ring and a salient of said ductile ring is forced into said circumferential reentrant groove.

2. The pipe connection according to claim 1, further comprising:
a plurality of pressure projections situated upon the interior surface of said tightening nut so as to apply pressure to said ductile ring as said tightening nut is engaged.

3. The pipe connection according to claim 1, further comprising:
a plurality of pressure projections situated upon the interior surface of said body screw so as to apply pressure to said ductile ring as said tightening nut is engaged.

4. The pipe connection according to claim 1, further comprising:
a plurality of pressure projections situated upon the exterior surface of said ductile ring so as to apply pressure to said ductile ring as said tightening nut is engaged.

5. The pipe connection according to claim 2, wherein said pressure projections are situated at an angle relative to the axis of said first and second pipe ends.

6. The pipe connection according to claim 1, further comprising:
an auxiliary ring situated within said ductile ring to form a angle unitary ring structure with a thin portion of said auxiliary ring projecting axially along the circumference of said ductile ring; and a packing seal disposed so as to engage said projecting portion of said auxiliary ring when said tightening nut is engaged.

7. The pipe connection according to claim 1, wherein said ductile ring further comprises:
a circumferential locking projection on the interior surface, arranged so as to engage said reentrant groove.

8. The pipe connection according to claim 2, wherein said ductile ring further comprises:
a gap in said ductile ring to allow the circumference of said ductile ring to decrease as said tightening nut is engaged.

9. The pipe connection according to claim 8, further comprising:
a narrow connection spanning said gap in said ductile ring, to allow said pressure projections to slide across said gap in said ductile ring without becoming lodged in said gap in said ductile ring.