GB2137710A - Branch pipe fitting - Google Patents
Branch pipe fitting Download PDFInfo
- Publication number
- GB2137710A GB2137710A GB08308801A GB8308801A GB2137710A GB 2137710 A GB2137710 A GB 2137710A GB 08308801 A GB08308801 A GB 08308801A GB 8308801 A GB8308801 A GB 8308801A GB 2137710 A GB2137710 A GB 2137710A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fitting
- winding
- mat
- pipe
- saddle
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D23/00—Producing tubular articles
- B29D23/001—Pipes; Pipe joints
- B29D23/003—Pipe joints, e.g. straight joints
- B29D23/005—Pipe joints, e.g. straight joints provided with electrical wiring
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
- B29C45/14065—Positioning or centering articles in the mould
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
- B29C45/14639—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
- B29C70/82—Forcing wires, nets or the like partially or completely into the surface of an article, e.g. by cutting and pressing
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Branch Pipes, Bends, And The Like (AREA)
Abstract
An electro-fusion saddle fitting 1 for connecting a branch pipe to a main pipe is manufactured by winding uncoated resistance heating wire onto a rubber mat (10) having spaced radial webs (13) with grooves (14) to receive the wire and locate the winding, moulding the body of the fitting over the mat and winding, and removing the mat to leave the winding partially embedded in the body. The pipe fitting is suitable for thermoplastic pipes. <IMAGE>
Description
SPECIFICATION
Branch pipe fitting for thermoplastic pipe
This invention relates to branch of saddle fittings for connecting a branch pipe to a main pipe of Thermoplastic material, such as polyethylene. A saddle fitting generally consists of a part-cylindrical body having a concave surface corresponding to the external shape of the main pipe to which it is to be attached, and an integral tubular boss projecting outwardly from the body for connection of a branch pipe, the fitting being moulded from a material which is compatible with, and preferably the same as that of the main pipe so that the fitting can be welded directly to the main pipe.The invention is particularly concerned with saddle fittings of the electrofusion type which include an electrical resistance heating element to which an electric current can be supplied to heat and fuse the material of the fitting to that of the main pipe.
In order to ensure a satisfactory weld between the saddle fitting and pipe it is desirable that the heating element be located as close as possible to the surface of the pipe so that the material of the pipe is sufficiently heated and softened. The invention resides in a novel method of manufacturing a saddle fitting and more especially of mounting the heating element at the inner surface of the fitting. The invention also includes a fitting made by the method.
The feature of the invention will become clear from the following detailed description which is given with reference to the accompanying drawings in which:~
Figure 1 is a plan view of a saddle fitting;
Figure 2 is an end view of the fitting; and
Figure 3 is a top view of a preform used in the manufacture of the fitting.
The saddle fitting illustrated in Figures 1 and 2 has a generally semi-cylindrical body 1, an upwardly projecting tubular boss 2 for connection of a branch pipe, lateral flanges 3 for clamping the fitting to a pipe during welding thereto, and electrical connector sockets 5, 6 having pin contacts 7, 8 connected to the opposite ends of an electrical resistance heating winding located at the inner surface of the body 1. The fitting is formed by injection moulding and the heating element is secured in position during the moulding process, as will become clear from the following description of the manufacturing method.
In Figure 3 there is shown a flexible preform in the form of a thin rubber mat 10. The mat has a central aperture 1 1 and a series of uniformly spaced radial openings 12 of substantially segmental shape which separate webs 13. On the upper side of the mat the webs are provided with grooves 14 which constitute successive portions of a continuous spiral.
As a preliminary step before moulding the saddle fitting, uncoated resistance heating wire is wound into the grooves 14 of the mat 10 to form a spiral winding thereon, and the opposite ends of the windings are connected to respective contact pins 7, 8. The mat 10 with the winding carried thereon is then loaded into the injection mould, the mat being supported against the mould surface which forms the inner surface of the eventual fitting and the contacts 7, 8 being inserted into location holes provided in the mould.
After closing the mould thermoplastic material is injected into the mould cavity over the mat 10 and the winding. Those portions of the spiral winding which extend across the openings 12 become embedded in thermoplastic material but those portions within the grooves 14 of webs 13 do not.
When the moulding process is complete the fitting is removed from the mould and the rubber mat 10 is peeled away from the fitting to leave the spiral winding secured firmly in position at the inner surface of the fitting. In the completed saddle fitting alternate sections of the heating wire are fully embedded in the material of fitting and exposed at the inner surface which ensures that the winding is adequately secured but at the same time an underlying pipe will be adequately heated when an electric current is supplied to the winding to weld the fitting to the pipe.
While a single spiral winding has been described it will be understood that other configurations are possible and that the shape of the moulded rubber preform may be varied without departing from the invention. For example, it is not essential to have the openings 12 and the grooves 14 could instead be provided in mat portions 13 separated by mat portions 12 of reduced thickness. The winding portions between the grooves 14 will still become substantially entirely embedded in the fitting material.
1. A method of manufacturing an electro-fusion fitting comprising a body of thermoplastic material and an electrical resistance heating winding, wherein uncoated resistance wire is wound onto a flexible support member having means to retain the winding in a predetermined configuration, the body of the fitting is moulded over the support member and winding, and the support member is removed to leave the winding partially embedded in the body of the fitting.
2. A method according to claim 1, wherein the support member is a flat mat.
3. A method according to claim 2, wherein the mat is made of rubber.
4. A method according to claim 2, wherein the mat includes a plurality of spaced web portions having grooves to receive and locate the wire.
5. A method according to claim 3, wherein the webs extend substantially radially and are separated by either openings or reduced thickness mat portions whereby sections of the winding
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (7)
1. A method of manufacturing an electro-fusion fitting comprising a body of thermoplastic material and an electrical resistance heating winding, wherein uncoated resistance wire is wound onto a flexible support member having means to retain the winding in a predetermined configuration, the body of the fitting is moulded over the support member and winding, and the support member is removed to leave the winding partially embedded in the body of the fitting.
2. A method according to claim 1, wherein the support member is a flat mat.
3. A method according to claim 2, wherein the mat is made of rubber.
4. A method according to claim 2, wherein the mat includes a plurality of spaced web portions having grooves to receive and locate the wire.
5. A method according to claim 3, wherein the webs extend substantially radially and are separated by either openings or reduced thickness mat portions whereby sections of the winding between the webs become substantially entirely embedded in the material of the body.
6. A method of manufacturing an electro-fusion fitting substantially as herein described.
7. An electro-fusion fitting made by the method of any one of the preceding claims.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08308801A GB2137710B (en) | 1983-03-30 | 1983-03-30 | Branch pipe fitting |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08308801A GB2137710B (en) | 1983-03-30 | 1983-03-30 | Branch pipe fitting |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8308801D0 GB8308801D0 (en) | 1983-05-11 |
GB2137710A true GB2137710A (en) | 1984-10-10 |
GB2137710B GB2137710B (en) | 1986-06-11 |
Family
ID=10540492
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08308801A Expired GB2137710B (en) | 1983-03-30 | 1983-03-30 | Branch pipe fitting |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2137710B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2186524A (en) * | 1986-02-18 | 1987-08-19 | Alh Syst Ltd | Addition of a branch fitting to a pipe |
US4956138A (en) * | 1987-08-17 | 1990-09-11 | Glynwed Tubes And Fittings Limited | Method of manufacturing an electrofusion coupler |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1149716A (en) * | 1966-03-18 | 1969-04-23 | Atlantic Res Corp | Improvements in or relating to welding units and method of making them |
GB1408844A (en) * | 1972-02-08 | 1975-10-08 | Rollmaplast Ag | Boring saddles for branch pipe connections |
GB2083406A (en) * | 1980-08-29 | 1982-03-24 | Sturm Werner | Thermoplastic welding sleeve and a mold assembly for making same |
-
1983
- 1983-03-30 GB GB08308801A patent/GB2137710B/en not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1149716A (en) * | 1966-03-18 | 1969-04-23 | Atlantic Res Corp | Improvements in or relating to welding units and method of making them |
GB1408844A (en) * | 1972-02-08 | 1975-10-08 | Rollmaplast Ag | Boring saddles for branch pipe connections |
GB2083406A (en) * | 1980-08-29 | 1982-03-24 | Sturm Werner | Thermoplastic welding sleeve and a mold assembly for making same |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2186524A (en) * | 1986-02-18 | 1987-08-19 | Alh Syst Ltd | Addition of a branch fitting to a pipe |
US4956138A (en) * | 1987-08-17 | 1990-09-11 | Glynwed Tubes And Fittings Limited | Method of manufacturing an electrofusion coupler |
US5096632A (en) * | 1987-08-17 | 1992-03-17 | Glynwed Tubes & Fittings Limited | Method of manufacturing an electrofusion coupler |
Also Published As
Publication number | Publication date |
---|---|
GB8308801D0 (en) | 1983-05-11 |
GB2137710B (en) | 1986-06-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JPH0375795B2 (en) | ||
EP0396273A3 (en) | Electro-fusion fittings | |
US5697143A (en) | Method of manufacturing an electrofusion coupler | |
GB2312264A (en) | Pipe fitting construction and method | |
EP0119061B1 (en) | Improvements in or relating to weldable pipe fittings | |
GB2137710A (en) | Branch pipe fitting | |
GB2137297A (en) | Branch pipe fitting for thermoplastic pipe | |
JPH0739120B2 (en) | Manufacturing method of welded joint | |
WO1995015253A1 (en) | Joining of hollow elongate members | |
JP3571839B2 (en) | Electric fusion joint | |
JP2000161580A (en) | Electric fusion joint | |
JPH11502780A (en) | Manufacturing of electric welding joints | |
JPH079480A (en) | Manufacture of cap for blocking cap | |
JP3571763B2 (en) | Electric welding branch pipe joint | |
JP3701153B2 (en) | Electric fusion joint molding equipment | |
JP3143838B2 (en) | Manufacturing method of electric fusion joint | |
JPH09229282A (en) | Manufacture for electrical fusion joint | |
JPH0727282A (en) | Electro-fusion joint and its forming method | |
GB2189190A (en) | Branch pipe fitting for thermoplastic pipe | |
JPH0648237Y2 (en) | Welding joint | |
JPH07151289A (en) | Electric fused coupling | |
JP3325335B2 (en) | Manufacturing method of branch joint for electric welding | |
GB2137298A (en) | Branch pipe fitting | |
JPH0642689A (en) | Mat, manufacture of electrofusion saddle joint and joint | |
JP3288182B2 (en) | Manufacturing method of electrofusion joint |
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 |
Effective date: 19950330 |