CA1118011A - Sleeve made from thermoplastic material for joining thermoplastic line elements - Google Patents
Sleeve made from thermoplastic material for joining thermoplastic line elementsInfo
- Publication number
- CA1118011A CA1118011A CA000326278A CA326278A CA1118011A CA 1118011 A CA1118011 A CA 1118011A CA 000326278 A CA000326278 A CA 000326278A CA 326278 A CA326278 A CA 326278A CA 1118011 A CA1118011 A CA 1118011A
- Authority
- CA
- Canada
- Prior art keywords
- turns
- sleeve
- pipe length
- heating wire
- mandrel
- 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.)
- Expired
Links
- 229920001169 thermoplastic Polymers 0.000 title claims description 7
- 239000012815 thermoplastic material Substances 0.000 title claims description 7
- 239000004416 thermosoftening plastic Substances 0.000 title claims description 7
- 238000010438 heat treatment Methods 0.000 claims abstract description 32
- 239000000463 material Substances 0.000 claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- 238000004804 winding Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 8
- 239000004033 plastic Substances 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 2
- 230000004224 protection Effects 0.000 abstract description 5
- 230000002311 subsequent effect Effects 0.000 abstract 1
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- BALXUFOVQVENIU-KXNXZCPBSA-N pseudoephedrine hydrochloride Chemical compound [H+].[Cl-].CN[C@@H](C)[C@@H](O)C1=CC=CC=C1 BALXUFOVQVENIU-KXNXZCPBSA-N 0.000 description 1
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
- B29C61/00—Shaping by liberation of internal stresses; Making preforms having internal stresses; Apparatus therefor
- B29C61/06—Making preforms having internal stresses, e.g. plastic memory
- B29C61/0608—Making preforms having internal stresses, e.g. plastic memory characterised by the configuration or structure of the preforms
- B29C61/0625—Preforms comprising incorporated or associated heating means
-
- 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
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3404—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint
- B29C65/342—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint comprising at least a single wire, e.g. in the form of a winding
-
- 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
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3472—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint
- B29C65/3476—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint being metallic
-
- 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
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/66—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by liberation of internal stresses, e.g. shrinking of one of the parts to be joined
- B29C65/68—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by liberation of internal stresses, e.g. shrinking of one of the parts to be joined using auxiliary shrinkable elements
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/05—Particular design of joint configurations
- B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
- B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
- B29C66/112—Single lapped joints
- B29C66/1122—Single lap to lap joints, i.e. overlap joints
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5221—Joining tubular articles for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5229—Joining tubular articles involving the use of a socket
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/63—Internally supporting the article during joining
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/90—Measuring or controlling the joining process
- B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
- B29C66/914—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux
- B29C66/9161—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the heat or the thermal flux, i.e. the heat flux
- B29C66/91651—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the heat or the thermal flux, i.e. the heat flux by controlling or regulating the heat generated by Joule heating or induction heating
-
- 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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L47/00—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
- F16L47/02—Welded joints; Adhesive joints
- F16L47/03—Welded joints with an electrical resistance incorporated in the joint
-
- 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
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3468—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special electrical connectors of windings
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/347—General aspects dealing with the joint area or with the area to be joined using particular temperature distributions or gradients; using particular heat distributions or gradients
-
- 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
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5229—Joining tubular articles involving the use of a socket
- B29C66/52291—Joining tubular articles involving the use of a socket said socket comprising a stop
- B29C66/52294—Joining tubular articles involving the use of a socket said socket comprising a stop said stop being heated
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Branch Pipes, Bends, And The Like (AREA)
- Lining Or Joining Of Plastics Or The Like (AREA)
- Shaping Of Tube Ends By Bending Or Straightening (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A sleeve member formed from a pipe length by expansion is placed over a mandrel onto which are wound the spaced turns of an electric resistance heating wire. By heating the sleeve member the latter is shrunk onto the turns. By electrically producing heat in the wire, material flows around the expanding turns and embed the latter completely in a sleeve member projecting material portions being formed in the vicinity of turns. Thus, protection against electric shock hazards is obtained for turns and subse-quent working is made unnecessary for the recessed edge portions of inner wall which deform inwards during manufacture.
A sleeve member formed from a pipe length by expansion is placed over a mandrel onto which are wound the spaced turns of an electric resistance heating wire. By heating the sleeve member the latter is shrunk onto the turns. By electrically producing heat in the wire, material flows around the expanding turns and embed the latter completely in a sleeve member projecting material portions being formed in the vicinity of turns. Thus, protection against electric shock hazards is obtained for turns and subse-quent working is made unnecessary for the recessed edge portions of inner wall which deform inwards during manufacture.
Description
The invention relates to a sleeve made from thermoplas-tic material ~o~ joining thermoplastic line members with a shell-like sleeve member formed from a pipe length on whose inner wall are arranged the turns of an electrical resistance heating wire, and a method for the manufacture of the welded sleeve.
It is known to use shell-like, thermoplastic sleeves with a cylindrical sleeve member in whose inner wall is embedded an electrical resistance heating wire in shaped juxtaposed turns for joining thermoplastic line elements, i.e. pipe lengths, shaped parts and control members, e.g. valves.- Due to the heat produced electrically in the resistance heating wire the thermoplastic material of the welded sleeve and the ends of the line elements covered by the welded sleeve are caused to flow at the adjacent surface portions and are welded together. In this way, it is possible to produce drip-proof and pressure-tight joints in a simple manner.
The manufacture of such sleeves appears to be relatively simple, particularly in the case of the most frequently encountered ~ line diameters of up to about lOO mm. Sleeves for such sizes are more particularly produced by injection moulding of the sleeve member in which the resistance heating wire is embeddedin different~
ways in the sleeve member. It is relatively simple to injection mould round a carrier sleeve onto which is wound the resistance ;
heating wire. However, it is also possible to provide a helical slot on the inner wall of the sleeve member and to embed the resis-tance heating wire therein, the latter optionally being covered to . . .
j, ~
provide pro-tection against electric shock hazard.
~ owever, if larger sleeve diameters are required account mus~ be taken of various problems. As only smaller quantities of such sleeves are required, it is advantageous ;
to be able to obviate the use of an expensive injection mould of the type advantageously used for injection moulding of standard sleeve sizes, whereby the sleeve instead is made from a pipe length. The problem is then to arrange the resistance heating wire in suitable manner in the form of turns in the vicinity of th~ inner wall of the pipe length. As there are also connections for connecting the resistance heating wire with a - ' i -power supply, a relatively large amount of manual labour is C involved in the case of ~e ~e~d sleeves made from pipe lengths. If one of the known methods is used in which the resistance heating wire is placed in a helical slot made in the inner wall the manufacture of said slot constitutes an additional operation. A further additional operation is necessary if protection against the electric shock hazards is also required.
The present invention provides a sleeve of the type described hereinbefore in which it is possible to insert and connect the resistance wire to the sleeve member without additional processing operations and whilst simultaneously achieving a suitable protection against electric shock hazards.
According to the present invention there is provided a sleeve made from thermoplastic material for joining thermo-plastic line elements to a shell-like sleeve member which comprises having adjacent an inner wall thereof, a plurality of turns of an electrical resistance heating wire, said turns of the resistance heating wire, which serve to produce the connection to the line elements, being embedded in a portion of said sleeve which extends only partially along said sleeve and projects radially inwardly of the inner wall of a recessed por-tion without said turns such that the diameter of said turns is less than the 3Vl~
inner diameter of said recessed portion.
Thus r accoraing to the p~esent invention, that portion o~ the sleeve member includi~ng the electrical resistance heating wire turns serving to produce the connection with the line elements, radially inwardly projec-ts with respect to the inner wall o~ the pipe length to embed and cover the wire. As a result, the turns of the resistance heating wire are located in the vicinity of the inner wall of the sleeve member, whilst also providing an adequate protection against electric shock hazard.
The present invention also provides a method for the manufacture ofthe~sleeve according~to the invention comprising:
expanding a p~pe length; winding an electrical resistance heating wire onto a mandrel whose external diameter is smaller than the in-ternal diameter o~ che widened pipe length, reduced by at least double the thickness of the resistance heating wire; placing the pipe length on the mandrel; shrinking the pipe length on the man-drel in a zone at elevated temperature; causing electrical heat production in the resistance heating wire until material flow~
and penetrates the turns thereof; and cooling the pipe length on the winding mandrel and ejecting the cooled pipe length therefrom.
The invention is explained in greater detail hereinafter relative to a non-limitative embodiment and with reference to the drawings, wherein:
Fig. 1 is a vertical section through a partly repre-sented sleeve and two ends of line elements;
Fig. 2 is a detail of the sleeve of Fig. 1, and;
Fig. 3 is a modifica-tion of the detail of the sleeve of Fig. 1.
Referring to the accompanying drawings, the joining of the ends of two line elements 1, 2, ,,,, ~ 011 .g. p~pe lengths shown in Fig 1 i8 ef~ected by .. means of ~ x-~ff~hh~sleeve 3 wh~ch extends l~lf~
way o~er each of the end~ of the line elements 1, 2.
The ~o-~el~4~ sleeve 3 ha~ a sleeve member 4 ~ormed from a thermoplastic material and which is e.g~ ~
pipe length separated from ~ pipe h~ving a const~nt-~all thicknes~. An elec~rical resi~tan~e heating wire 6 la~d in diagram~atically represen~ed spaced turns 7 is emb~dded ~n the inner walL 5 of sleeve member 4. The turns 7 are laid in two s~p~rate areas dis~inguished by a material portion 8, 9 cover~ng turns 7 and projecting with r~spect to inner wall 5.
Fig 1 shows that the projec~ing material portion~ 8, 9 do not extend up to the edge of the sleeve member 4 and instead only extend over the re~ion of turns 7.
A further, n~rrow mater~al poxtion 10 is provided between the two material portions 85 9 and in which is provided a connecting wire 11 for connecting the turns 7 of the two materlal portlorls 8, 9.
A bore 12 is provided on each o~ the tw~ ends of ~leeve m~m~er 4 for receiYln~ a contact ~tud 13 ~xed in a suppo~king pl~te L4. ~ e supporting plate 14 is supported in the bottom o~ bore 12 and covers `:~
the connectio~ of the resistance heating wires 6 to contact stud 130 A not shown bush ~a~ be placed on co~tact studs 13, thereby produc~ he connection to the power supply for ma~ing a welded ~oint.
Fig 1 shows that the inner ~all 5 of sle~ve member 4 sta~ds back at khe edges. Whe~ making the slee~e from ~ pipe leDgth ~k i~ una~oidable that the ends w~ll be ~omew~t ~n~ardLy defor~ed~ As a result of the p~ojecting materi~l portlon~ 8~ 9 the otherwise ec~ssa~y aft~r~work~g of inner w~ll 5 alollg th~ edga portions ~s elimina~ed.
, he man~lfacture of ~he ~se-~¢~de~ sleeve 3 according to Fig 1 i8 described by mea~s of Figs 2 and 3. In the simplest embodiment (F~g 3) the resistance heat~
ing w~re 6 with a predetermined 8pacing of turns 7 is wound onto A winding mandrel 15 made ~or exa~2le ~om a pl~tics ~aterial, e~g. PTFE. ~e sleeve member 4 prepared rom a pipe len~th is widened unt~l ~t can bei placed over the windin~ mandrel 15 with the wou~d resi~tance heating wire 6. SlePve member 4 is now shrunk on the winding mandrel 15 in a heating ~urnace and re~ts on the turns 7. The resistance heat~ng wire 6 is now connected to a power supply ~nd heat is produced in turns 7 which makes the inner wall 5 flow. Sleeve member 4 now shrinks `~ ~urther ~ntil it engages on the w ffiding mandrel 15 w~lst ~imultaneously the w~re 6 e~)andQ so that it completely ~urrounds the material of sleeve me~ber 4~ The resistance heating w~re 6 displaces the mater~al fonming the pro~ecting material portion 8 or 9 having a thic~ness of at least approximately O.~mm which i~ sufficient to obviate a~er-working o~ the edge portions of inner wall 5. After ~ooll~g~
~he windi~ mandrel 15 i5 e~ected and the arc welded sleeve ls re~dy for us~.
If th~ker mat~rial p~rtions 8, 9 are required, the resls~anc~ heat~ng w~re 6 ~an be wound onto a plastic c~sin~ 16 ~s 8hoW~ by dotted l~es ln Fig 2~ The ~hrinka~e of sleeve member 4 ~ak~ place ln the ma~ner deseribed hereinbe~ore. Th~ final st~te ls show~ ~ F~g 2. The plas ic c~sing 16 1~ ~olned com~
pletely ~o s1aeve member 4 and form3 o~e of the pro-~8C~i~g material portion~ 8~ 9 in ~hich are smbQdded ~ 7~
the tu~n~ 7. Th~ maker~al thickn~ss over turn 7 c~n be 0.5mm or mor~ The plastic casing 16 with the wound resi~tance heating wire 6 can optionally be placed on a supp~rting mandrel if cas~ng 16 cannot in ~tself form the wlndlng mandrelO
Th~ plastic caslng 16 can ~e replAced by a plRstic~
encased resistance heating wire 6 wound onto the winding mandrel 159 cf Flg 3~ The covering 1~ then forms the projecting material portion instead ~
the plastic casing 16 of Fig 2. The shrinkage o~
~leeve member 4 takes place ~n the ~ama way.
It i~ also possible to expand the windinO mandrel 15 a~ter winding on the resistance heat~ng wire 6~
e,~ by produci~ an lnternal pressure within the .
win~ing mandrel 15. The sle~ve member 4 is shrunk in the manner described herei~before9 but during the productîon of heat in turn~ 17~ the expan~ion is slowly cancelled out~ s~ that the material can con~ue to ~low and ~orm a thicker msterlal portlo~
: ~0 8, 9. If the ~ame or a similar material as used or sleeve member 4 ~s used for the p~st~c casing 16 (Fig 2~ and for the covering 17 (Fig 3) a un~form cohesive body is ~or~ed in ~hich turn~ 7 are ~mbedded in a completely covered manner. A~ a result of the above-described method, ~anual ~ter^working is essentiall~ llmited to the connecSl~g of the re~ist~
ance heating w~re to h~ contac stud 13.
It is known to use shell-like, thermoplastic sleeves with a cylindrical sleeve member in whose inner wall is embedded an electrical resistance heating wire in shaped juxtaposed turns for joining thermoplastic line elements, i.e. pipe lengths, shaped parts and control members, e.g. valves.- Due to the heat produced electrically in the resistance heating wire the thermoplastic material of the welded sleeve and the ends of the line elements covered by the welded sleeve are caused to flow at the adjacent surface portions and are welded together. In this way, it is possible to produce drip-proof and pressure-tight joints in a simple manner.
The manufacture of such sleeves appears to be relatively simple, particularly in the case of the most frequently encountered ~ line diameters of up to about lOO mm. Sleeves for such sizes are more particularly produced by injection moulding of the sleeve member in which the resistance heating wire is embeddedin different~
ways in the sleeve member. It is relatively simple to injection mould round a carrier sleeve onto which is wound the resistance ;
heating wire. However, it is also possible to provide a helical slot on the inner wall of the sleeve member and to embed the resis-tance heating wire therein, the latter optionally being covered to . . .
j, ~
provide pro-tection against electric shock hazard.
~ owever, if larger sleeve diameters are required account mus~ be taken of various problems. As only smaller quantities of such sleeves are required, it is advantageous ;
to be able to obviate the use of an expensive injection mould of the type advantageously used for injection moulding of standard sleeve sizes, whereby the sleeve instead is made from a pipe length. The problem is then to arrange the resistance heating wire in suitable manner in the form of turns in the vicinity of th~ inner wall of the pipe length. As there are also connections for connecting the resistance heating wire with a - ' i -power supply, a relatively large amount of manual labour is C involved in the case of ~e ~e~d sleeves made from pipe lengths. If one of the known methods is used in which the resistance heating wire is placed in a helical slot made in the inner wall the manufacture of said slot constitutes an additional operation. A further additional operation is necessary if protection against the electric shock hazards is also required.
The present invention provides a sleeve of the type described hereinbefore in which it is possible to insert and connect the resistance wire to the sleeve member without additional processing operations and whilst simultaneously achieving a suitable protection against electric shock hazards.
According to the present invention there is provided a sleeve made from thermoplastic material for joining thermo-plastic line elements to a shell-like sleeve member which comprises having adjacent an inner wall thereof, a plurality of turns of an electrical resistance heating wire, said turns of the resistance heating wire, which serve to produce the connection to the line elements, being embedded in a portion of said sleeve which extends only partially along said sleeve and projects radially inwardly of the inner wall of a recessed por-tion without said turns such that the diameter of said turns is less than the 3Vl~
inner diameter of said recessed portion.
Thus r accoraing to the p~esent invention, that portion o~ the sleeve member includi~ng the electrical resistance heating wire turns serving to produce the connection with the line elements, radially inwardly projec-ts with respect to the inner wall o~ the pipe length to embed and cover the wire. As a result, the turns of the resistance heating wire are located in the vicinity of the inner wall of the sleeve member, whilst also providing an adequate protection against electric shock hazard.
The present invention also provides a method for the manufacture ofthe~sleeve according~to the invention comprising:
expanding a p~pe length; winding an electrical resistance heating wire onto a mandrel whose external diameter is smaller than the in-ternal diameter o~ che widened pipe length, reduced by at least double the thickness of the resistance heating wire; placing the pipe length on the mandrel; shrinking the pipe length on the man-drel in a zone at elevated temperature; causing electrical heat production in the resistance heating wire until material flow~
and penetrates the turns thereof; and cooling the pipe length on the winding mandrel and ejecting the cooled pipe length therefrom.
The invention is explained in greater detail hereinafter relative to a non-limitative embodiment and with reference to the drawings, wherein:
Fig. 1 is a vertical section through a partly repre-sented sleeve and two ends of line elements;
Fig. 2 is a detail of the sleeve of Fig. 1, and;
Fig. 3 is a modifica-tion of the detail of the sleeve of Fig. 1.
Referring to the accompanying drawings, the joining of the ends of two line elements 1, 2, ,,,, ~ 011 .g. p~pe lengths shown in Fig 1 i8 ef~ected by .. means of ~ x-~ff~hh~sleeve 3 wh~ch extends l~lf~
way o~er each of the end~ of the line elements 1, 2.
The ~o-~el~4~ sleeve 3 ha~ a sleeve member 4 ~ormed from a thermoplastic material and which is e.g~ ~
pipe length separated from ~ pipe h~ving a const~nt-~all thicknes~. An elec~rical resi~tan~e heating wire 6 la~d in diagram~atically represen~ed spaced turns 7 is emb~dded ~n the inner walL 5 of sleeve member 4. The turns 7 are laid in two s~p~rate areas dis~inguished by a material portion 8, 9 cover~ng turns 7 and projecting with r~spect to inner wall 5.
Fig 1 shows that the projec~ing material portion~ 8, 9 do not extend up to the edge of the sleeve member 4 and instead only extend over the re~ion of turns 7.
A further, n~rrow mater~al poxtion 10 is provided between the two material portions 85 9 and in which is provided a connecting wire 11 for connecting the turns 7 of the two materlal portlorls 8, 9.
A bore 12 is provided on each o~ the tw~ ends of ~leeve m~m~er 4 for receiYln~ a contact ~tud 13 ~xed in a suppo~king pl~te L4. ~ e supporting plate 14 is supported in the bottom o~ bore 12 and covers `:~
the connectio~ of the resistance heating wires 6 to contact stud 130 A not shown bush ~a~ be placed on co~tact studs 13, thereby produc~ he connection to the power supply for ma~ing a welded ~oint.
Fig 1 shows that the inner ~all 5 of sle~ve member 4 sta~ds back at khe edges. Whe~ making the slee~e from ~ pipe leDgth ~k i~ una~oidable that the ends w~ll be ~omew~t ~n~ardLy defor~ed~ As a result of the p~ojecting materi~l portlon~ 8~ 9 the otherwise ec~ssa~y aft~r~work~g of inner w~ll 5 alollg th~ edga portions ~s elimina~ed.
, he man~lfacture of ~he ~se-~¢~de~ sleeve 3 according to Fig 1 i8 described by mea~s of Figs 2 and 3. In the simplest embodiment (F~g 3) the resistance heat~
ing w~re 6 with a predetermined 8pacing of turns 7 is wound onto A winding mandrel 15 made ~or exa~2le ~om a pl~tics ~aterial, e~g. PTFE. ~e sleeve member 4 prepared rom a pipe len~th is widened unt~l ~t can bei placed over the windin~ mandrel 15 with the wou~d resi~tance heating wire 6. SlePve member 4 is now shrunk on the winding mandrel 15 in a heating ~urnace and re~ts on the turns 7. The resistance heat~ng wire 6 is now connected to a power supply ~nd heat is produced in turns 7 which makes the inner wall 5 flow. Sleeve member 4 now shrinks `~ ~urther ~ntil it engages on the w ffiding mandrel 15 w~lst ~imultaneously the w~re 6 e~)andQ so that it completely ~urrounds the material of sleeve me~ber 4~ The resistance heating w~re 6 displaces the mater~al fonming the pro~ecting material portion 8 or 9 having a thic~ness of at least approximately O.~mm which i~ sufficient to obviate a~er-working o~ the edge portions of inner wall 5. After ~ooll~g~
~he windi~ mandrel 15 i5 e~ected and the arc welded sleeve ls re~dy for us~.
If th~ker mat~rial p~rtions 8, 9 are required, the resls~anc~ heat~ng w~re 6 ~an be wound onto a plastic c~sin~ 16 ~s 8hoW~ by dotted l~es ln Fig 2~ The ~hrinka~e of sleeve member 4 ~ak~ place ln the ma~ner deseribed hereinbe~ore. Th~ final st~te ls show~ ~ F~g 2. The plas ic c~sing 16 1~ ~olned com~
pletely ~o s1aeve member 4 and form3 o~e of the pro-~8C~i~g material portion~ 8~ 9 in ~hich are smbQdded ~ 7~
the tu~n~ 7. Th~ maker~al thickn~ss over turn 7 c~n be 0.5mm or mor~ The plastic casing 16 with the wound resi~tance heating wire 6 can optionally be placed on a supp~rting mandrel if cas~ng 16 cannot in ~tself form the wlndlng mandrelO
Th~ plastic caslng 16 can ~e replAced by a plRstic~
encased resistance heating wire 6 wound onto the winding mandrel 159 cf Flg 3~ The covering 1~ then forms the projecting material portion instead ~
the plastic casing 16 of Fig 2. The shrinkage o~
~leeve member 4 takes place ~n the ~ama way.
It i~ also possible to expand the windinO mandrel 15 a~ter winding on the resistance heat~ng wire 6~
e,~ by produci~ an lnternal pressure within the .
win~ing mandrel 15. The sle~ve member 4 is shrunk in the manner described herei~before9 but during the productîon of heat in turn~ 17~ the expan~ion is slowly cancelled out~ s~ that the material can con~ue to ~low and ~orm a thicker msterlal portlo~
: ~0 8, 9. If the ~ame or a similar material as used or sleeve member 4 ~s used for the p~st~c casing 16 (Fig 2~ and for the covering 17 (Fig 3) a un~form cohesive body is ~or~ed in ~hich turn~ 7 are ~mbedded in a completely covered manner. A~ a result of the above-described method, ~anual ~ter^working is essentiall~ llmited to the connecSl~g of the re~ist~
ance heating w~re to h~ contac stud 13.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A sleeve made from thermoplastic material for joining thermoplastic line elements to a shell-like sleeve member which comprises a pipe length having adjacent an inner wall thereof, a plurality of turns of an electrical resistance heating wire, said turns of the resistance heating wire, which serve to produce the connection to the line elements, being embedded in a portion of said sleeve which extends only partially along said sleeve and projects radially inwardly of the inner wall of a recessed portion without said turns such that the diameter of said turns is less than the inner diameter of said recessed portion.
2. A sleeve according to claim 1, wherein the projecting portion comprises a material applied with the turns to the inner wall of the pipe length.
3. A sleeve according to claim 1, wherein the projecting portion is part of the pipe length material.
4. A sleeve according to claim 1, 2 or 3, wherein the projecting portion projects at least 0.1 mm.
5. A sleeve according to claim 1, 2 or 3, wherein the thickness of material covering the turns is at least 0.5 mm.
6. A method for the manufacture of a sleeve made from thermoplastic material for joining thermoplastic line elements to a shell-like sleeve member which comprises: expanding a pipe length; winding a resistance heating wire onto a mandrel whose external diameter is smaller than the internal diameter of the widened pipe length, reduced by at least double the thickness of the resistance heating wire; placing the pipe length on the mandrel; shrinking the pipe length on the mandrel in a zone at elevated temperature; causing electrical heat production in the resistance heating wire until material flows and penetrates the turns thereof; and cooling the pipe length on the winding mandrel and ejecting the cooled pipe length therefrom.
7. A method according to claim 6, wherein the diameter of the mandrel is widened after winding on the resistance heating wire and is reduced during the material flow due to electrical heat production.
8. A method according to claim 7, wherein the resistance wire is wound onto a non-conductive mandrel, and the latter is welded to the pipe length.
9. A method according to claim 8, in which the non-conductive mandrel is made of plastic.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH476078A CH630162A5 (en) | 1978-05-02 | 1978-05-02 | ELECTRIC WELDING SLEEVE MADE OF THERMOPLASTIC MATERIAL. |
| CH4760/78-4 | 1978-05-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1118011A true CA1118011A (en) | 1982-02-09 |
Family
ID=4282034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000326278A Expired CA1118011A (en) | 1978-05-02 | 1979-04-25 | Sleeve made from thermoplastic material for joining thermoplastic line elements |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0015958B1 (en) |
| JP (1) | JPS6340993B2 (en) |
| AT (1) | AT360293B (en) |
| BE (1) | BE875992A (en) |
| CA (1) | CA1118011A (en) |
| CH (1) | CH630162A5 (en) |
| DE (2) | DE2947583D2 (en) |
| GB (1) | GB2036518B (en) |
| IT (1) | IT1112585B (en) |
| NL (1) | NL7903215A (en) |
| SE (1) | SE457556B (en) |
| WO (1) | WO1979001018A1 (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH644054A5 (en) * | 1980-03-31 | 1984-07-13 | Fischer Ag Georg | WELDING SLEEVE FOR THERMOPLASTIC MATERIALS, METHOD AND DEVICE FOR THEIR PRODUCTION. |
| EP0058175B2 (en) * | 1980-08-22 | 1992-05-06 | Industrial Pipe Systems Pty. Limited | Electric fusion pipe fittings |
| GB2090558B (en) * | 1981-01-06 | 1984-08-30 | British Gas Corp | Method of manufacture of a heat sealable fitting and fitting made by such method |
| FR2503020A1 (en) * | 1981-04-02 | 1982-10-08 | Rech Applic Plastiques Et | Heating coil inserts for fusing thermoplastic pipe socket joints - preformed so that the concealed wire is adjacent to the interface |
| FR2516439A1 (en) * | 1981-11-13 | 1983-05-20 | Armosig | Electrically fusible liners for thermoplastic pipework joints - pre-assembled by partial fusion for satisfactory alignment |
| DE3204681C2 (en) * | 1982-02-11 | 1986-02-06 | Friedrichsfeld Gmbh, Steinzeug- Und Kunststoffwerke, 6800 Mannheim | Method and device for embedding an electrical heating wire in a sleeve-like plastic part |
| CH657907A5 (en) * | 1982-06-23 | 1986-09-30 | Von Roll Ag | SLEEVE MADE OF THERMOPLASTIC MATERIAL FOR CONNECTING PIPE ELEMENTS. |
| DE3272031D1 (en) * | 1982-10-05 | 1986-08-21 | Rech Et D Applic Des Plastique | Electrical plastic welding sleeve and method for its manufacture |
| US4626308A (en) * | 1983-02-18 | 1986-12-02 | The Victaulic Company Plc | Method of making welded pipe joints |
| GB8719430D0 (en) * | 1987-08-17 | 1987-09-23 | Glynwed Tubes & Fittings | Manufacturing electrofusion coupler |
| GB8910070D0 (en) * | 1989-05-03 | 1989-06-21 | Fusion Plastics Ltd | Electro-fusion fittings |
| JP2736805B2 (en) * | 1989-05-19 | 1998-04-02 | 日本鋼管継手株式会社 | Synthetic resin pipe fittings |
| JPH03793U (en) * | 1989-05-26 | 1991-01-08 | ||
| GB2235740B (en) * | 1989-08-22 | 1992-12-23 | British Gas Plc | Grouted pipe joint for polyolefin-lined pipes |
| FI87318C (en) * | 1991-06-14 | 1992-12-28 | Kwh Pipe Ab Oy | FOERFARANDE FOER SKARVNING AV SPIRALLINDADE TERMOPLASTROER |
| JPH0715602A (en) * | 1993-06-15 | 1995-01-17 | Toshiba Corp | Image data processor |
| GB2299047A (en) * | 1995-03-21 | 1996-09-25 | Uponor Ltd | Manufacture of electrofusion fittings |
| DE19628916A1 (en) * | 1995-10-12 | 1997-04-17 | Fischer Georg Rohrleitung | Sleeve for connecting pipe parts |
| FR2748415B1 (en) * | 1996-05-09 | 1998-06-26 | Etex De Rech Tech Soc | CONNECTING ELEMENT FOR AN ASSEMBLY OF THERMOPLASTIC MATERIALS BY WELDING AND METHOD FOR MANUFACTURING SUCH AN ELEMENT |
| CN113580588A (en) * | 2021-08-10 | 2021-11-02 | 安徽杰蓝特新材料有限公司 | Processing technology of extrusion type RTP composite pressure pipe fitting |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL236188A (en) * | 1958-02-17 | |||
| CH515449A (en) * | 1970-09-08 | 1971-11-15 | Rollmaplast Ag | Electrically weldable plastic pipe socket with protection against accidental contact |
| CH544906A (en) * | 1971-11-12 | 1974-01-15 | Gerbert & Cie | Electrically heatable welding socket and process for their manufacture |
| DE2760064C2 (en) * | 1976-03-22 | 1983-09-01 | Werner 4614 Hägendorf Sturm | Welding socket made of thermoplastic material |
| CH622870A5 (en) * | 1977-06-03 | 1981-04-30 | Werner Sturm |
-
1978
- 1978-05-02 CH CH476078A patent/CH630162A5/en not_active IP Right Cessation
-
1979
- 1979-04-24 NL NL7903215A patent/NL7903215A/en not_active Application Discontinuation
- 1979-04-25 CA CA000326278A patent/CA1118011A/en not_active Expired
- 1979-04-27 AT AT320779A patent/AT360293B/en not_active IP Right Cessation
- 1979-04-27 IT IT22232/79A patent/IT1112585B/en active
- 1979-04-30 DE DE79CH7900060D patent/DE2947583D2/en not_active Expired
- 1979-04-30 DE DE2947583A patent/DE2947583C1/en not_active Expired
- 1979-04-30 WO PCT/CH1979/000060 patent/WO1979001018A1/en unknown
- 1979-04-30 GB GB7943944A patent/GB2036518B/en not_active Expired
- 1979-04-30 JP JP54500697A patent/JPS6340993B2/ja not_active Expired
- 1979-05-02 BE BE0/194953A patent/BE875992A/en not_active IP Right Cessation
- 1979-12-04 EP EP79900439A patent/EP0015958B1/en not_active Expired
- 1979-12-05 SE SE7910020A patent/SE457556B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| ATA320779A (en) | 1980-05-15 |
| SE7910020L (en) | 1979-12-05 |
| DE2947583C1 (en) | 1987-04-23 |
| SE457556B (en) | 1989-01-09 |
| BE875992A (en) | 1979-11-05 |
| GB2036518B (en) | 1982-11-03 |
| AT360293B (en) | 1980-12-29 |
| GB2036518A (en) | 1980-06-25 |
| JPS6340993B2 (en) | 1988-08-15 |
| JPS55500479A (en) | 1980-07-31 |
| WO1979001018A1 (en) | 1979-11-29 |
| NL7903215A (en) | 1979-11-06 |
| EP0015958A1 (en) | 1980-10-01 |
| CH630162A5 (en) | 1982-05-28 |
| EP0015958B1 (en) | 1983-11-09 |
| IT1112585B (en) | 1986-01-20 |
| DE2947583D2 (en) | 1980-11-13 |
| IT7922232A0 (en) | 1979-04-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |