IL104377A

IL104377A - Pipe coupling

Info

Publication number: IL104377A
Application number: IL10437793A
Authority: IL
Original assignee: Plasson Maagan Michael Ind Ltd
Priority date: 1993-01-13
Filing date: 1993-01-13
Publication date: 1995-08-31
Also published as: ES1027099Y; FR2700379B3; CN2190215Y; ITMI940015U1; IT232672Y1; FR2700379A3; IL104377A0; ITMI940015V0; ES1027099U

Description

IMPROVED PIPE COUPLING IMPROVED PIPE COUPLING The present invention relates to an improved pipe coupling and, in particular, to a pipe coupling using a sealing ring and a bushing.

Pipe couplings come in various shapes and sizes, but generally include two main parts: a housing formed with external threads and with an internal axial bore having at least one open end for receiving the end of a pipe, and a collar formed at one end with internal threads cooperable with the threads of the housing and capable of tightly clamping the pipe to the housing upon threading the collar into the housing. An essential property of a pipe coupling is that the interface between the pipe coupling and the pipe be hermetically sealed so that no liquid can escape from the coupling. This is usually accomplished by the placing of a sealing ring between the outer wall of the pipe and the inner wall of the housing of the pipe coupling. This sealing ring is generally made of an elastic material such as rubber and is tightly pressed onto the inner wall of the housing by the pipe, thereby hermetically sealing the space between the walls.

In order to retain the sealing ring in place, a recessed shoulder recessed from the open end of the bore is generally built into the inner wall of the housing, on which the sealing ring can rest, and a bushing is placed over the sealing ring to keep it in place. A cap or collar is then screwed onto the end of the housing to clamp the pipe to the housing and keep the bushing in place.

A disadvantage of this type of coupling is that when the collar is unscrewed and the pipe removed, for instance when the sealing ring has to be serviced or replaced, the bushing and sealing ring can easily fall out. It is known that this disadvantage can be overcome by using a pipe coupling which has an annular rib protruding from the inner wall of the housing and a bushing with a corresponding annular groove. The bushing can be snapped into place and will not fall out when the collar is removed. This type of bushing, however, is quite difficult to remove, as the rib extends 360° around the inner wall of the bore and holds the bushing quite securely.

An object of the present invention is therefore to provide an improved pipe coupling wherein the bushing is held in place even without the pressure of the collar on it, while at the same time the bushing is capable of being removed fairly easily for servicing or replacing the sealing ring.

According to the present invention there is thus provided a pipe coupling comprising a housing having an internal axial bore with an open end for receiving one end of a pipe, said bore having a recessed annular shoulder defining a seat for a sealing ring and a circumferentially-extending rib protruding from the inner wall of said bore; a sealing ring; and a bushing formed with an annular groove capable of receiving said rib for constraining said sealing ring; said rib being located between said recessed shoulder and said open end for effecting a snap-action fitting of said bushing thereby forming together with said shoulder an interspace for insertion of said sealing ring; characterized in that said rib extends less than 180° around said inner wall thereby facilitating the removal of said bushing.

The invention also provides a pipe coupling comprising a housing as described above formed with external threads, a sealing ring and bushing as described above, a collar formed at one end with internal threads cooperable with said external threads of said housing, and a split-ring insertable into said collar for clamping said pipe to said housing.

In a preferred embodiment of the invention, the the rib extends between 100° and 160°. In a most preferred embodiment, the rib extends 150°. This angle allows the bushing to be held firmly in place while still being removable by pushing up the side of the bushing not held by the rib.

An additional advantage in having a rib of less than 180° is that it facilitates the removal of the housing from the mold during the manufacturing process of the housing .

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein : Fig. 1 is a longitudinal exploded sectional side view illustrating one form of pipe coupling constructed in accordance with the present invention; Fig. 2 is an end view of a preferred embodiment of the housing of the pipe coupling of Fig. 1; and Fig. 3 is an enlarged fragmentary sectional view of the housing along line III--III of Fig. 2 with the sealing ring and bushing in place.

With reference first to Fig. 1, there is illustrated a pipe coupling according to one embodiment of the invention which includes a housing 2, a sealing ring 4, an annular bushing 6, a split-ring 8 and a collar 10. The components of the pipe coupling (except for the sealing ring) are preferably made from a hard plastic material such as polypropylene, but other materials can also be used.

The particular housing of Fig. 1 is of a reducing pipe coupling with a narrower end 12 and a wider end 14. The housing is formed with external threads 16 at the wider end 14, and defines an internal axial bore 18. The inner wall 24 of the housing 2 has an outer recessed annular shoulder 26 and an inner recessed annular shoulder 20 for purposes to be described below. A rib 22 protrudes from the inner wall 24 slightly under the outer recessed shoulder 26. Fig. 2 illustrates a preferred embodiment of the invention wherein the rib extends 150°.

The sealing ring 4, which is usually in the shape of an "0"-ring, rests on the inner shoulder 20 and is held in place by the bushing 6. Bushing 6 has an out-turned rim or flange 28 and an annular groove 30 positioned under the flange 28 in allignment with the position of the rib 22 in relation to shoulder 26. Split-ring 8 has been previously described in Israel Patents No. 47642 and 49577 to the applicant, as well as in co-pending Israel Application No. 96515, also to the applicant. It has an outer conical surface 32. Collar 10 is formed at one end with internal threads 34 cooperable with external threads 16 of the housing and at the other end with an inner conical surface 36 engageable with the outer conical surface 32 of the split-ring.

On assembly, the end of a pipe (not shown) is passed through collar 10, split-ring 8, bushing 6 and sealing-ring 4, in the order and orientation illustrated in Fig. 1. The end of the pipe is then inserted into the opening 14 of the housing 2, and collar 10 is screwed onto the housing by its threads 34 engaging the threads 16 of the housing. The sealing ring 4 is pressed against the inner recessed shoulder 20, and bushing 6 is snapped into place above the sealing ring, with the flange 28 pressed against the outer shoulder 26 by the split-ring 8. Further details concerning the construction and assembly of the pipe coupling can be found in the aforementioned Israel Patents.

The arrangement of the foregoing elements in the assembled condition of the pipe coupling is illustrated in Fig. 3. The sealing ring 4 rests on the inner shoulder 20.

A narrow space 38 separates the ring 4 from the bushing 6 in order to allow expansion of the sealing ring by the pressure from the pipe. The flange 28 of the bushing is pressed onto the outer shoulder 26 and the groove 30 snugly envelops the rib 22 thereby effecting a snap-action fitting.

Since the rib protrudes for less than half of the circumference of the inner wall 24 of the housing, the bushing can be removed fairly easily by inserting an object such as a finger through the center hole of the bushing and pushing one side, preferrably the side without the rib, in an upward pivotal movement.

While the invention has been described with respect to one preferred embodiment, it will be appreciated that various modifications and improvements are also to be included within the scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A pipe coupling comprising a housing having an internal axial bore with an open end for receiving one end of a pipe, said bore having a recessed annular shoulder defining a seat for a sealing ring and a circumferentially -extending rib protruding from the inner wall of said bore, a sealing ring, and a bushing formed with an annular groove capable of receiving said rib for constraining said sealing ring, said rib being located between said recessed shoulder and said open end for effecting a snap-action fitting of said bushing thereby forming together with said shoulder an interspace for insertion of said sealing ring, characterized in that said rib extends less than 180° around said inner wall thereby facilitating the removal of said bushing .

2. The pipe coupling according to claim Λ, wherein the rib extends between 100° and 160°.

3. The pipe coupling according to claim 1, wherein the rib extends for 150°.

4. The pipe coupling according to any of claims 1 to 3 wherein said bushing is formed with an annular flange at one end of the bushing.

5. The pipe coupling according to claim 4 wherein said internal bore has a second recessed annular shoulder adjacent to said open end defining a seat for said flange of said bushing.

6. The pipe coupling according to claim 5 wherein said rib is adjacent to said second recessed shoulder.

7. The pipe coupling according to any of claims 1 to 6, said housing being formed with external threads, said coupling further comprising a collar formed at one end with threads cooperable with said external threads of said housing, and a split-ring insertable into said collar for clamping said pipe to said housing.

8. A pipe coupling substantially as described with reference to and as illustrated in the accompanying drawings. ney Tel-Aviv 61 230