GB2075141A

GB2075141A - Pipe joints and pipe couplings

Info

Publication number: GB2075141A
Application number: GB8014475A
Authority: GB
Original assignee: British Steel Corp
Current assignee: British Steel Corp
Priority date: 1980-05-01
Filing date: 1980-05-01
Publication date: 1981-11-11

Abstract

The invention provides a coupling for pipes or pipe like members 1 including a unitary annular sleeve member 2 having open ends; two pairs of separate annular grooves 5,6 disposed around the inner wall of the sleeve member 2 and spaced from the open end thereof; a resilient elastomeric annular member 9 located in the annular groove of each pair of grooves nearer to each open end of the sleeve member and adapted to constitute a sealing member for the coupling; and a spring washer 7 located in the annular groove of each pair of grooves further from the respective open end of the sleeve member and having radially inwardly extending teeth which, in an unstressed condition, project beyond the internal wall of the sleeve member 2 and are inclined in a direction axially inwardly of the sleeve member. <IMAGE>

Description

SPECIFICATION Improvements in or relating to pipe joints and pipe couplings This invention relates to pipe joints and pipe couplings. More particularly the invention relates to such joints and couplings for connecting pipes or pipe like members of plastics or relatively soft metals such as copper to other pipes or pipe like members or to pipe work fittings such as elbows, "T" junctions, valves, etc.

According to the invention there is provided a coupling for pipes or pipe like members including a unitary annular sleeve member having an open end; two separate annular grooves disposed around the inner wall of the sleeve member and spaced from the open end thereof; a resilient elastomeric annular member located in the annular groove of the two grooves nearer to open end of the sleeve member and adapted to constitute a sealing member for the coupling; and a spring washer located in the annular groove of the two grooves further from the open end of the sleeve member and having radially inwardly extending teeth which, in an unstressed condition, project beyond the internal wall of the sleeve member and are inclined in a direction axially inwardly of the sleeve member.

The spring washer is preferably in the form of a split ring in order to aid the fitting of the washer within its groove during assembly of the coupling.

We have found that the construction of coupling according to the invention is particularly beneficial. The location of the sealing member and spring washer in separate grooves is especially advantageous in that sealing and locking of the coupling is completely satisfactory whilst the risk of interference between sealing member and spring washer is removed, and at the same time good support can be provided, particularly for the spring washer, by appropriate dimensioning of the walls of the grooves.

The sleeve member may be of metal or may be of plastics material, for example, a polyethylene material such as a cross-linked polyethylene.

The resilient elastomeric annular member may be in the form of "0" ring and may be of ejrcular or oval cmss section or other sec tion.

With a coupling according to the invention as hereinabove defined, the joint is made by inserting a pipe (of a sliding fit) into the open end of the sleeve member. The sealing member is deformed and compmssed by the pipe as it is inserted so as to provide its required sealing effect. The teeth of the spring washer are then deflected axially inwardly of the sleeve member (i.e. the direction of their original inclination) by the passage of the pipe. Any subsequent attempt to remove the pipe will tend to straighten the deflected teeth of the spring washer which will therefore bite into the pipe and resist outward movement of the pipe.

The sleeve member may be part of a pipe fitting of the kind mentioned earlier or may be a double ended sleeve having two internal grooves, spring washers, and sealing members at each end so as to provide a coupling member as such between two pipes or pipe like members.

In order that the invention may be more readily understood one embodiment thereof will now be described by way of example with reference to the accompanying drawing which is a sectional elevation of a joint illustrating a coupling in accordance with the invention.

The joint shown in the Figure is intended for use with, for example, a hot water pipe work system and includes two pipe 1 of crosslinked polyethylene, and a coupling connecting the two pipes including a unitary sleeve member 2 of the same material.

The pipes 1 are each provided with internal metal ferrules 3 adjacent their ends to provide greater rigidity to the pipes within the coupling.

The sleeve member 2 is provided with two grooves 4 and 5 at each end, the inner grooves 4 carrying stainless steel spring washers 6 having radially inwardly extending teeth 7 which project inwardly of the internal wall and of the sleeve member 2. The washers are in the form of split rings (not shown).

The outer grooves 5 of the sleeve member 2 carry sealing members 9 in the form of "O" rings of rubber resistant to the effects of hot water such as an ethylene propylene copolymer rubber.

The sleeve member 1 is provided with a centrally located internal annular ridge 10 intended to limit the penetration of each of the pipes within the sleeve.

The coupling illustrated is assembled by springing the split ring washers 6 into grooves 4 and then pushing "0" rings 9 into grooves 5.

As can be seen from the figure, the pipe 1 is a sliding fit within sleeve 2 and annular insert 7. When fitted within the sleeve 2, the pipe compresses the sealing member 9 from its normal circular cross-section thereby effecting a normal compression seal.

Movement of the pipe 1 inwardly axially of the coupling past the teeth 7 of the washer 6 has resulted in the pipe being scored as indicated at 11. Any atternpt to remove the pipe 1 from the sleeve 2 in the position indicated in the figure will tend to straighten the teeth 7 which will thereby bite further into the pipe 1 resisting removal thereof.

1. A coupling for pipes or pipe like mem

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to pipe joints and pipe couplings This invention relates to pipe joints and pipe couplings. More particularly the invention relates to such joints and couplings for connecting pipes or pipe like members of plastics or relatively soft metals such as copper to other pipes or pipe like members or to pipe work fittings such as elbows, "T" junctions, valves, etc. According to the invention there is provided a coupling for pipes or pipe like members including a unitary annular sleeve member having an open end; two separate annular grooves disposed around the inner wall of the sleeve member and spaced from the open end thereof; a resilient elastomeric annular member located in the annular groove of the two grooves nearer to open end of the sleeve member and adapted to constitute a sealing member for the coupling; and a spring washer located in the annular groove of the two grooves further from the open end of the sleeve member and having radially inwardly extending teeth which, in an unstressed condition, project beyond the internal wall of the sleeve member and are inclined in a direction axially inwardly of the sleeve member. The spring washer is preferably in the form of a split ring in order to aid the fitting of the washer within its groove during assembly of the coupling. We have found that the construction of coupling according to the invention is particularly beneficial. The location of the sealing member and spring washer in separate grooves is especially advantageous in that sealing and locking of the coupling is completely satisfactory whilst the risk of interference between sealing member and spring washer is removed, and at the same time good support can be provided, particularly for the spring washer, by appropriate dimensioning of the walls of the grooves. The sleeve member may be of metal or may be of plastics material, for example, a polyethylene material such as a cross-linked polyethylene. The resilient elastomeric annular member may be in the form of "0" ring and may be of ejrcular or oval cmss section or other sec tion. With a coupling according to the invention as hereinabove defined, the joint is made by inserting a pipe (of a sliding fit) into the open end of the sleeve member. The sealing member is deformed and compmssed by the pipe as it is inserted so as to provide its required sealing effect. The teeth of the spring washer are then deflected axially inwardly of the sleeve member (i.e. the direction of their original inclination) by the passage of the pipe. Any subsequent attempt to remove the pipe will tend to straighten the deflected teeth of the spring washer which will therefore bite into the pipe and resist outward movement of the pipe. The sleeve member may be part of a pipe fitting of the kind mentioned earlier or may be a double ended sleeve having two internal grooves, spring washers, and sealing members at each end so as to provide a coupling member as such between two pipes or pipe like members. In order that the invention may be more readily understood one embodiment thereof will now be described by way of example with reference to the accompanying drawing which is a sectional elevation of a joint illustrating a coupling in accordance with the invention. The joint shown in the Figure is intended for use with, for example, a hot water pipe work system and includes two pipe 1 of crosslinked polyethylene, and a coupling connecting the two pipes including a unitary sleeve member 2 of the same material. The pipes 1 are each provided with internal metal ferrules 3 adjacent their ends to provide greater rigidity to the pipes within the coupling. The sleeve member 2 is provided with two grooves 4 and 5 at each end, the inner grooves 4 carrying stainless steel spring washers 6 having radially inwardly extending teeth 7 which project inwardly of the internal wall and of the sleeve member 2. The washers are in the form of split rings (not shown). The outer grooves 5 of the sleeve member 2 carry sealing members 9 in the form of "O" rings of rubber resistant to the effects of hot water such as an ethylene propylene copolymer rubber. The sleeve member 1 is provided with a centrally located internal annular ridge 10 intended to limit the penetration of each of the pipes within the sleeve. The coupling illustrated is assembled by springing the split ring washers 6 into grooves 4 and then pushing "0" rings 9 into grooves 5. As can be seen from the figure, the pipe 1 is a sliding fit within sleeve 2 and annular insert 7. When fitted within the sleeve 2, the pipe compresses the sealing member 9 from its normal circular cross-section thereby effecting a normal compression seal. Movement of the pipe 1 inwardly axially of the coupling past the teeth 7 of the washer 6 has resulted in the pipe being scored as indicated at 11. Any atternpt to remove the pipe 1 from the sleeve 2 in the position indicated in the figure will tend to straighten the teeth 7 which will thereby bite further into the pipe 1 resisting removal thereof. CLAIMS

1. A coupling for pipes or pipe like mem bers including a unitary annular sleeve member having an open end; two separate annular grooves disposed around the inner wall of the sleeve member and spaced from the open end thereof; a resilient elastomeric annular member located in the annular groove of the two grooves nearer to open end of the sleeve member and adapted to constitute a sealing member for the coupling; and a spring washer located in the annular groove of the two grooves further from the open end of the sleeve member and having radially inwardly extending teeth which, in an unstressed condition, project beyond the internal wall of the sleeve member and are inclined in a direction axially inwardly of the sleeve member.

2. A coupling according to claim 1 wherein the spring washer is in the form of a split ring.

3. A coupling according to claim 1 or 2 wherein the sleeve member is of metal.

4. A coupling according to claim 1 or 2 wherein the sleeve member is of polyethylene material.

5. A coupling according to claim 1 or 2 wherein the sleeve member is of a crosslinked polyethylene.

6. A coupling according to any one of the preceding claims wherein the resilient elastomeric annular member is in the form of an "0" ring.