PIPE CONNECTOR

Abstract: The invention discloses a pipe connector (20; 56; 98) for plastics pipes (36, 38; 72, 74) including a tubular body (22; 58; 104) having at least one open end (24, 26;60, 62); an exterior thread (28, 30; 64, 66) provided at each open end (24, 26; 60, 62) of the tubular body (22; 58; 104); a connecting ring (32, 34; 68, 70) for each open end (24, 26; 60, 62) of the tubular body (22; 58; 104), each connecting ring (32, 34; 68, 70) being provided with an interior thread (40; 78) adapted to co-operate with the exterior thread (28, 30; 64, 66) at its open end (24, 26; 60, 62) of the tubular body (22; 58; 104), the connecting ring (32, 34; 68, 70) being adapted to be fitted to the tubular body (22;58; 104) by turning the interior thread (40; 78) into the exterior thread (28, 30; 64, 66) on the tubular body (22; 58; 104); and an annular inwardly directed gripping formation (44; 82) provided in the connecting ring (32, 34; 68, 70) for gripping sealingly onto a plastics pipe (36, 38; 72, 74) inserted through the connecting ring (32, 34; 68, 70) and preventing withdrawal of an inserted plastics pipe (36, 38; 72, 74) from the connecting ring (32, 34; 68, 70).

Description: Pipe connector. FIELD OF INVENTION The present invention relates to a pipe connector. BACKGROUND TO INVENTION Numerous pipe connectors for connecting plastics pipes or tubes together are known. Some examples of prior art pipe connectors are the following: US 2,269,629 (Kreidel) shows a tube coupling with a coupling sleeve, which is internally threaded, which co-operates with a body, which is externally threaded. The tube is caused to divert at one end and is gripped by way of a gripping ring. Bunyan (US 4,153,656) discloses a pipe joint in which a sleeve is placed over the adjacent ends of pipes. The sleeve fits with clearance around the pipe ends and the ends of the clearance space are closed by inflating hollow sealing rings and then epoxy resin is injected into the clearance space to fill the space. Bϋrli (US 4,735,442) describes a plastics pipe connection, in which a coupling sleeve is pushed onto a plastics pipe and provided with barbs drawn over a driving shoulder against the connecting piece by a union nut. In US 4,946,213 (Guest) a tube coupling is illustrated. This coupling has a coupling body with a through-way through which a tube can pass. A complicated structure provides for attachment of tubes. Bartholomew (US 5,425,557) illustrates a hose coupling for use with flexible hoses. It includes a bi-conical fitting which is inserted into a hose end and a frusto-conical locking device located about the hose portion. In a further patent of Bartholomew (US 5,524,939) a hose coupling is disclosed, which is similar to that shown in the previous patent specification. In yet a further patent of Bartholomew (US 5,568,948) a hose couphng is shown which is similar to the other two above except for slight variations. Verbeck (US 5,709,417) discloses a pipe coupling, which has threaded sections inside each end portion which grip the outer walls of a plain end pipe which is forced axially thereon. In one known commercial type of pipe connector is adapted to receive the ends of plastics pipes to be connected together and these are inserted into the pipe connector where they are received in a sealing manner. However, once inserted and fixed in position the plastics pipes generally cannot be removed. This has a definite disadvantage as often the length of the pipes have been miscalculated or a variation is otherwise necessary. In such a case the plastics pipes would have to be removed from the pipe connector but this is not possible. Only with great difficulty such plastics pipes can be removed from the pipe connector and normally and therefore the pipe connection is discarded and a new pipe connector is used. This results in a considerable waste and unnecessary expense. Generally the above pipe connectors are complicated and expensive to produce, and often cannot be taken apart for re-use if required. It is an object of the invention to suggest a pipe connector which is relatively cheap to produce and which renders itself to be re-used if required. In the specification hereinafter the expression "connecting ring" is to include any cylindrical member of which its internal diameter has any proportional relationships to its axial length, i.e. it can be more, or less or equal. SUMMARY OF INVENTION According to the invention, a pipe connector for plastics pipes is characterized thereby that it includes a tubular body having at least one open end; an exterior thread provided at each open end of the tubular body; a connecting ring for each open end of the tubular body, each connecting ring being provided with an interior thread adapted to cooperate with the exterior thread at its open end of the tubular body, the connecting ring being adapted to be fitted to the tubular body by turning the interior thread into the exterior thread on the tubular body; and an annular inwardly directed gripping formation provided in the connecting ring for gripping sealingly onto a plastics pipe inserted through the connecting ring and preventing withdrawal of an inserted plastics pipe from the connecting ring. The connecting ring may have an inwardly directed collar on which the gripping formation is located, the gripping formation having a diameter which is less than the internal diameter of the tubular body. A sealing ring may have provided inside each connecting ring adjacent to the collar, the sealing ring being adapted to be pressed against an end face of the tubular body when the connecting ring is fitted thereto. The sealing ring may have a rectangular shape in cross-section or a round shape in cross-section. An external collar may be provided on the tubular body adjacent each exterior thread. A sealing ring may have provided on the tubular body between each external collar and the adjacent thread. The exterior thread may be tapered and the interior thread may be non- tapered. The tubular body may have any suitable shape, such as an elbow piece, a T-piece, a straight connector, a reducer or an end pipe connector with only one open end. The tubular body and the connecting ring may be injection moulded of suitable plastics material. The pipe connector may be intended for connecting plastics pipes used in irrigation or for transmission of water. Also according to the invention a connecting ring for an open end of a tubular body of a pipe connector for plastics pipes, the pipe connector having an exterior thread adjacent each open end, is characterized thereby that it is provided with an interior thread adapted to co-operate with the exterior thread at its open end of the tubular body, that it is adapted to be fitted to the tubular body by turning the interior thread into the exterior thread on the tubular body; and that it has an annular inwardly directed gripping formation for gripping seaHngly onto a plastics pipe inserted through it. BRIEF DESCRIPTION OF DRAWINGS The invention will now be described by way of example with reference to the accompanying schematic drawings. In the drawings there is shown in: Figure 1 a side view of a first embodiment of a pipe connector in accordance with the invention connecting two plastics pipes; Figure 2 a side view of the tubular body of the pipe connector shown in Figure 1 without the plastics pipes to be connected and without the connecting rings at its opposite ends; Figure 3 a side view of the connecting ring of the pipe connector shown in Figure 1; Figure 4 an end view of the connecting ring seen along arrow IV in Figure 3; Figure 5 a sectional side view of the connecting ring seen along arrows V-V in Figure 4; Figure 6 on an enlarged scale, a side view of part of the connecting ring as indicated by arrow VI in Figure 1 and also showing a plastics pipe in position and part of the tubular body with dotted lines; Figure 7 a side view seen of a second embodiment of a pipe connector in accordance with the invention connecting two plastics pipes; Figure 8 a sectional side view of a pipe connector seen along arrows VIII- VIII in Figure 7; Figure 9 an exploded view of a pipe connector shown in Figures 7 and 8 but without the plastics pipes to be connected; Figure 10 a side view of a third embodiment of a pipe connector in accordance with the invention but without plastics pipes; Figure 11 a sectional side view of a pipe connector seen along arrows XI-XI in Figure 10; Figure 12 on an enlarged scale a detail of a rectangular shaped sealing ring and part of the pipe connector prior to compression as indicated by the arrow XII in Figure 8; Figure 13 a view corresponding to Figure 12 but on compression of the sealing ring; Figure 14 a view corresponding to Figure 12 but showing a round sealing ring or O-ring prior to compression; Figure 15 a view corresponding to Figure 14 but on compression of the sealing ring or O-ring; Figure 16 on reduced scale, an end stop pipe connector in accordance with the invention; Figure 17 on reduced scale, an elbow pipe connector in accordance with the invention; and Figure 18 on reduced scale, a T-piece pipe connector in accordance with the invention. DETAILED DESCRIPTION OF DRAWINGS Referring to Figures 1 to 6, the first embodiment of a pipe connector in accordance with the invention, generally referred to by reference numeral 20, includes a tubular body 22 provided at its opposite ends 24, 26 with two exterior threaded parts 28, 30 respectively. The threaded parts 28 and 30 taper narrowingly outwardly (see Figure 2) and are adapted to receive the connecting rings 32, 34. The connector 20 is adapted to connect two flexible plastics pipes 36, 38. As the threaded parts 28, 30 and the connecting rings 32, 34 are similar, hereafter reference will only be made to the threaded part 30 and the connecting ring 34. The connecting ring 34 includes an annular body 36 which is internally provided with threads 40 associated with the threads 30 on the connector body 22. The threads 40 may be tapered complementarily to the threaded part 30 if required. The ring 34 further has an inwardly directed collar 42 at one end 34.1 which defines a pointed annular gripping formation or ridge 44, which is directed towards the opposite end 34.2 of the ring 34. It must be noted that, in use, the connector 20 will be provided to the customer in assembled form, i.e. the connecting rings 32, 34 will be fitted to the tubular body 22 so that the end face 22.1 of the tubular body 22 abuts against the inside face 42.1 of the collar 42. The plastics pipes 36, 38 are fitted by the user as follows: The a pipe 38 is inserted into the ring 34 in the direction indicated by arrow 46 in Figures 5 and 6. (The tubular body 22 internally and centrally has at least one stop - which is not shown - and which will prevent the pipes 36, 38 from being pushed in too far). The gripping formation 44 grips into the material of the pipe 38. Thereby a required seal is provided to prevent any leakage and to prevent withdrawal of the pipe 38 from the ring 34 in a direction opposite to that indicated by arrow 46. The internal diameter 48 of the gripping formation 44 is slightly less than the internal diameter 50 of the tubular body 22 so that the external diameter 52 of the pipe 38 will be close to the internal face 22.2 of the tubular body 22 so as to prevent any "wobbling" of the pipe 38 therein. The internal diameter 48 of the gripping formation 44 is also slightly less than the external diameter 52 of the pipe 38 so that the gripping formation 44 will grip tightly and sealingly into the outer surface of the By means of the pipe connector 20 in accordance with the invention it is possible to re-use such a connector 20 if required by merely cutting the pipe 38 on the outside of the collar 42, then turning off the ring 34 from the body 22 and removing the cut-off pipe piece by pulling it through the ring 34 in the direction shown by arrow 46. For re-use of the pipe connector 20, new pipes 36, 38 then are fitted as described above. If required a sealing ring 54 may be provided inside the ring 34 adjacent the collar 42. On fitting the ring 34 to the threaded part 30, the end face 22.1 of the tubular body 22 will be pressed against the sealing ring 54 for providing a sealing contact. This sealing ring 54 will assist in preventing leakage of water from the pipe 38 along the threads 40 and the threaded part 30 to the outside. Referring to Figures 7, 8 and 9 a second embodiment of a pipe connector in accordance with the invention is shown. This pipe connector, generally indicated by reference numeral 56, includes a tubular body 58 provided at its opposite ends 60, 62 with two exterior threaded parts 64, 66 respectively. The threaded parts 64, 66 receive the connecting rings 68, 70. As the threaded parts 64, 66 and the connecting rings 68, 70 are similar, hereafter reference will only be made to the threaded part 64 and its associated connecting ring 68. The pipe connector 56 is adapted to connect two flexible plastics pipes 72, 74. The connecting ring 68 includes an annular body 76 which is internally provided with a thread 78 associated with the exterior thread 64 on the which extends an inwardly directed pointed annular gripping formation 82. A sealing ring 84 is located inside the ring 68 adjacent the collar 80. Also in this case, the pipe connector 56 (as is the case with the pipe connector 20) is pre-assembled in the factory in that the sealing ring 84 and the connecting rings 68, 70 are fitted to the tubular body 58 so that the face end 58.1 of the tubular body 58 presses against the sealing ring 84. In use, a user will insert a plastics pipe 72 into the ring 68 in the direction indicated by arrow 86 until the pipe abuts against the stop (or stops) 88 provided in the interior of the tubular body 58. The gripping formation 82 grips into the material of the plastics pipe 72 and thereby a seal is provided to prevent any leakage. The internal diameter 90 of the gripping formation 82 is slightly less than the internal diameter 92 of the tubular body 58 so that the external diameter 94 of the pipe 72 will be close to or substantially abut against the internal face 96 of the tubular body 58 so as to prevent any "wobbling" of the pipe 72 therein. The internal diameter 90 of the gripping formation 82 is also slightly less than the external diameter 94 of the pipe 72 so that the gripping formation 82 will grip tightly and sealingly into the outer surface of the pipe 72 and also prevents the plastics pipe 72 from being pulled out in a direction counter to the arrow 86. Also in this case the pipe connector 56 can be re-used if required by merely cutting the pipe 72 on the outside of the collar 80, then turning off the ring 68 from the tubular body 58 and removing the cut-off piece by pulling it through the ring 68 in the same direction as shown by arrow 86. Referring to Figures 10 and 11 a third embodiment of a pipe connector in accordance with the invention is shown. This pipe connector, generally indicated by reference numeral 98, is similar to the pipe connector 56 shown in Figures 7 to 9 and therefore the same reference numerals will be used to describe similar parts. To avoid repetition only the differences between the pipe connector 56 and the pipe connector 98 will be explained. In the pipe connector 98 external collars 100, 102 are provided on the tubular body 104 adjacent the threaded parts 64, 66 respectively. Sealing rings 106, 108 are located next to the collars 100, 102 as shown. In use when the rings 68, 70 are turned on to the tubular body 104 the end faces 68.1, 70.1 are pressed against the sealing rings 106, 108 respectively to provide the necessary sealing. The sealing rings 106, 108 are therefore provided in place of the sealing rings 84 used in the pipe connector 56 illustrated in Figures 7 to 9. However, if required both the sealing rings 106, 108 as well as sealing ring 84 may be used. Also in this case the pipe connector 98 can be re-used if required by merely cutting the plastics pipe 72 behind the ring 68 on the outside of the collar 80, then turning the ring 68 off the tubular body 104 and removing the cut-off piece by pulling it tiirough the ring 68 in the direction as shown by arrow 82. Figure 12 shows an enlarged part of the pipe connector 56 in Figure 8 with the rectangular sealing ring 84 prior to compression and in Figure 13 the sealing ring 84 is being compressed by the collar 80 of the ring 68 and expands as shown. Figures 14 and 15 are similar to Figures 12 and 13 but here a round sealing ring or O-ring 110 is used. In Figure 14 the round sealing ring 110 is shown prior to compression and in Figure 15 the sealing ring 110 is being compressed by the collar 80 of the ring 68 and thus takes up an oval cross-sectional shape. Figure 16 shows on a reduced scale an end pipe connector 112, which is similar to the pipe connectors illustrated in the preceding drawings, except that one end is closed off. Similarly Figure 17 shows an elbow pipe connector 114 and Figure 18 a T-piece pipe connector 116. In all three cases the connecting rings 118, 120, 122, 124, 126, 128 are similar to the rings 32, 34; 68, 70 and cooperate with threaded parts on the tubular bodies 130, 132, 134. In a practical embodiment of pipe connectors the following dimensions may exist: 1. Internal diameter of tubulat body (22; 58; 104) ±15,5mm ± 20,5mm ± 25,5mr 2. External diameter of plastics pipe (36, 38; 72, 74) 15mm 20mm 25mm 3. Internal diameter of gripping formation (44; 82) 13-14,5mm 17-19,5mm 23-24,5m The pipe connectors 10, 56, 98 may be injection moulded of suitable plastics material, e.g. ABS (copolymer range based on cyanoethene/but l,2;3,4-diene-phenylethene (acrilonitrile/butadiene/styrene)), styrene, polypropylene or nylon. The sealing rings 54, 84, 106, 108 may be made of suitable rubber (e.g. synthetic rubber) or plastics material, e.g. as soft PVC. The pipes 36, 38, 72, 74 may be made of suitable plastics material, e.g. LDPE (low density polyethylene) or flexible polypropylene. Reference numerals 20 pipe connector 22 tubular body 22.1 end face of tubular body 22 5 22.2 internal face of tubular body 22 24 end of tubular body 26 end of tubular body 28 exterior threaded part 30 exterior threaded part 10 30.1 end face of the exterior threaded part 32 connecting ring 34 connecting ring 36 flexible plastics pipe 36.1 internal face of annular body 36 15 38 flexible plastics pipe 40 thread 42 collar 42.1 inside face of collar 42 44 annular gripping formation 20 46 arrow 48 internal diameter of gripping formation 44 50 internal diameter of tubular body 22 52 external diameter of pipe 38 54 sealing ring 25 56 pipe connector 58 tubular body 60 end of tubular body 62 end of tubular body 64 threaded part 66 threaded part 68 connecting ring 70 connecting ring 72 plastics pipe 5 74 plastics pipe 76 annular body 78 thread 80 collar 82 annular gripping formation lo 84 sealing ring 86 arrow 88 stop 90 internal diameter of gripping formation 92 internal diameter of tubular body 58 15 94 external diameter of pipe 72 96 internal face of tubular body 58 98 pipe connector 100 collar 102 collar 20 104 tubular body 106 sealing ring 108 sealing ring 110 round sealing ring 112 end pipe connector 25 114 elbow pipe connector 116 T-piece pipe connector 118 connecting ring 120 connecting ring 122 connecting ring 30 124 connecting ring 126 connecting ring 128 connecting ring 130 tubular body 132 tubular body 134 tubular body

Claims: PATENT CLAIMS 1. A pipe connector (20; 56; 98) for plastics pipes (36, 38; 72, 74) characterized thereby that it includes a tubular body (22; 58; 104) having at least one open end (24, 26;60, 62); an exterior thread (28, 30; 64, 66) provided at each open end (24, 26; 60, 62) of the tubular body (22; 58; 104); a connecting ring (32, 34; 68, 70) for each open end (24, 26; 60, 62) of the tubular body (22; 58; 104), each connecting ring (32, 34; 68, 70) being provided with an interior thread (40; 78) adapted to co-operate with the exterior thread (28, 30; 64, 66) at its open end (24, 26; 60, 62) of the tubular body (22; 58; 104), the connecting ring (32, 34; 68, 70) being adapted to be fitted to the tubular body (22;58; 104) by turning the interior thread (40; 78) into the exterior thread (28, 30; 64, 66) on the tubular body (22; 58; 104); and an annular inwardly directed gripping formation (44; 82) provided in the connecting ring (32, 34; 68, 70) for gripping sealingly onto a plastics pipe (36, 38; 72, 74) inserted through the connecting ring (32, 34; 68, 70) and preventing withdrawal of an inserted plastics pipe (36, 38; 72, 74) from the connecting ring (32, 34; 68, 70). 2. A pipe connector as claimed in claim 1, characterized thereby that the connecting ring (32, 34; 68, 70) has an inwardly directed collar (42, 80) on which the gripping formation (44; 82) is located, the gripping formation (44; 82) having a diameter (48, 90) which is less than the internal diameter (50; 92) of the tubular body (22; 58; 104). 3. A pipe connector as claimed in claim 2, characterized thereby that a sealing ring (54; 84; 110) is provided inside each connecting ring (32, 34; 68, 70) adjacent to the collar (42), the sealing ring (54; 84; 110) being adapted to be pressed against an end face (22.1) of the tubular body (22; 58) when the connecting ring (32, 34; 68, 70) is fitted thereto. 4. A pipe connector as claimed in claim 3, characterized thereby that the sealing ring (84) has a rectangular shape in cross-section. 5. A pipe connector as claimed in claim 3, characterized thereby that the sealing ring (54; 110) has a round shape in cross-section. 6. A pipe connector as claimed in claim 1 or claim 2, characterized thereby that an external collar (100, 102) is provided on the tubular body (104) adjacent each exterior thread (64, 66). 7. A pipe connector as claimed in claim 6, characterized thereby that a sealing ring (106, 108) is provided on the tubular body (104) between each external collar (100, 102) and the adjacent thread (64, 66). 8. A pipe connector as claimed in any one of the preceding claims, characterized thereby that the exterior thread (28, 30) is tapered and the interior thread (40) is non-tapered. 9. A pipe connector as claimed in any one of the preceding claims, characterized thereby that the tubular body (22; 58; 104) has any suitable shape, such as an elbow piece (114), a T-piece (116), a straight connector (22; 58; 104), a reducer or an end pipe connector (112) with only one open end. 10. A pipe connector as claimed in any one of the preceding claims, characterized thereby that the tubular body (22, 58; 104) and the connecting ring (32, 34; 68, 70) are injection moulded of suitable plastics material. 11. A pipe connector as claimed in any one of the preceding claims, characterized thereby that it is intended for connecting plastics pipes (36, 38; 72, 74) used in irrigation or for transmission of water. 12. A connecting ring (32, 34; 68, 70) for an open end (24, 26; 60, 62) of a tubular body (22; 58; 104) of a pipe connector (20; 56; 98) for plastics pipes (36, 38; 72, 74), the pipe connector (20; 56; 98) having an exterior thread (28, 30; 64, 66) adjacent each open end (24, 26; 60, 62), characterized thereby that it is provided with an interior thread (40; 78) adapted to co-operate with the exterior thread (28, 30; 64, 66) at its open end (24, 26; 60, 62) of the tubular body (22; 58; 104), that it is adapted to be fitted to the tubular body (22; 58; 104) by turning the interior thread (40; 78) into the exterior thread (28, 30; 64, 66) on the tubular body (22; 58; 104); and that it has an annular inwardly directed gripping formation (44; 82) for gripping sealingly onto a plastics pipe (36, 38; 72, 74) inserted through it.

Inventors: VANNESTE MARCEL-ANDRE, VANNESTE, MARCEL-ANDRE
Applicants: VANNESTE MARCEL ANDRE, VANNESTE, MARCEL-ANDRE
Application year: 2001
Main classification: F16L47
IPC codes: F16L37