CH612489A5

CH612489A5 - Electrically heatable welding collar

Info

Publication number: CH612489A5
Application number: CH77977A
Authority: CH
Inventors: Peter Weber
Original assignee: Geberit Ag
Priority date: 1977-01-21
Filing date: 1977-01-21
Publication date: 1979-07-31

Abstract

The welding collar consists of thermoplastic material and is used for connecting plastic pipes. Accommodated in the collar is a heating wire winding (4) whose ends are passed to the exterior for connection to a power source. Bonded onto the collar is a temperature indicator (10) whose colour changes when the temperature increases. It is thus possible to check by simple visual inspection whether or not the correct welding temperature has been reached. <IMAGE>

Description

       

  
 



     PATENTANSPRUCHE   
1. Elektrisch heizbare Schweissmuffe aus thermoplastischem Material zum Verbinden von Kunststoffrohren mit in der Muffe untergebrachter Heizdrahtwicklung, deren Enden zwecks Anschluss an eine Stromquelle nach aussen   gefilint    sind, dadurch gekennzeichnet, dass auf der Muffe ein sich bei   Temperaturerhöhung      verfärbender    Temperaturindikator (10) angeordnet ist.



   2. Schweissmuffe nach Patentanspruch 1, dadurch gekennzeichnet, dass der aus Papier oder Kunststoff bestehende Temperaturindikator (10) neben den Anschlussbuchsen (7) auf der Muffe aufgeklebt ist.



   3. Schweissmuffe nach Patentanspruch 1, dadurch gekennzeichnet, dass der Temperaturindikator einen Farbpunkt (11) aufweist, der sich bei   Temperaturerhöhung    bleibend ver   färbt.   



   Die Erfindung betrifft eine elektrisch heizbare Schweissmuffe aus thermoplastischem Material zum   Verbinden    von Kunststoffrohren mit in der Muffe untergebrachter Heizdrahtwicklung, deren Enden zwecks Anschluss an eine Strom   queue    nach aussen   gefuhrt    sind.



   Solche Schweissmuffen haben zu einer grossen Rationalisierung bei der Herstellung von Kunststoff-Rohrverbindungen gefiihrt.



   Beim Zusammenbau von Rohrsystemen werden zweck   mässig    die   einzelnen      Rohrstilcke    und Muffen lose zusammengefiigt, um nachher gruppenweise verschweisst zu werden.



  Dabei muss jedesmal   flberprtift    werden, welche Verbindungen bereits verschweisst und welche noch zu verschweissen sind. Da sich bekannte Muffen   äusserlich    vor und nach der Verschweissung nicht unterscheiden, erfolgt diese   Prtifung    manuell, was nachteilig ist.



   Es kann aber auch vorkommen, dass in einem grossen Rohrsystem die Verschweissung   einzelner    Verbindungen vergessen wird oder aber auch, dass die notwendige Temperatur fiir eine einwandfreie Schweissung, z. B. infolge eines kurzen Stromausfalles, nicht erreicht wird. Schliesslich wurden schon infolge Unaufmerksamkeit des Handwerkers Schweissmuffen zweimal an die Stromquelle angeschlossen, was zu einer   Schwächung    der Verbindung   ftihrte.   



   Die Erfindung stellt sich daher zur Aufgabe, eine Schweissmuffe der eingangs   erwähnten    Gattung zu schaffen, bei welcher durch einfache Sichtkontrolle   llberprtift    werden kann, ob die Verschweissung bereits erfolgt und ob die richtige Schweisstemperatur erreicht ist oder nicht.



     Erflndungsgemiiss    wird dies so erreicht, dass auf der Muffe ein sich   beiTemperaturerhöhung      verfärbenderTemperatur-    indikator angeordnet ist.



   Nachfolgend wird anhand der Zeichnung ein   Ausftih-    rungsbeispiel einer Schweissmuffe   näher      erläutert.    Es zeigen:
Fig. 1 einen   Längsschnitt    durch eine Schweissmuffe, und
Fig. 2 eine Teilansicht der Schweissmuffe   gemäss    Fig. 1 im Bereich der Anschlussbuchse, von der   Stirnseite    her.



   Die in der Fig. 1 dargestellte, elektrisch heizbare Schweissmuffe weist einen zylindrischen   Körper    1 aus einem thermoplastischen Kunststoff, beispielsweise   Polyäthylen,    auf. Die Innenwand 2 des   Körpers    ist mit einer   schraubenlinienförmi-    gen Nut 3 versehen, in welche die Wicklung 4 eines Heizdrahtes eingelegt ist. Die Enden des Heizdrahtes sind durch zwei radiale Bohrungen 5 nach aussen   geftihrt    und mit zwei im   Körper    verankerten   Koataktstiicken    6 verbunden, welche   ihrerseits    durch zwei Buchsen 7 abgeschirmt sind.



   Die in der Fig. 1 gestrichelt angedeuteten   Rohre    8 werden beidseitig bis zum Anschlagring 9 in die Muffe eingeschoben.



  Sodann wird in bekannter Weise die Muffe durch den Heizdraht 4   erwärmt,    was eine Schrumpfung derselben und ein Verschweissen der Innenwand mit den   Rohrenden    bewirkt.



     Ms    Kontrolle fiir die richtig erfolgte Verschweissung ist ein   Wiirmeindikator    10 auf der Muffe angeordnet. Dieser an sich bekannte Indikator 10, beispielsweise aus Papier oder Kunststoff, wird   zweckmässig    neben den Buchsen 7 gut sichtbar auf der Muffe aufgeklebt, wobei die   Klebstelle    absolut   fettfrei    sein muss. Anhand der bleibenden   Verfärbung    des Indikators nach der Verschweissung der Muffe   liisst    sich feststellen, ob die korrekte Verschweissungstemperatur erreicht worden ist.



   Da beim Zusammenbau von   Rohrsystemen    die einzelnen   Rohrstilcke    und Muffen meist vorerst lose   zusammengefiigt    werden, um nachher gruppenweise verschweisst zu werden, kann anhand des Indikators sofort festgestellt werden, welche Verbindungen bereits verschweisst und welche noch zu verschweissen sind. Auf diese Weise   kbnnen    nachteilige Doppelverschweissungen vermieden werden, und es ist auch sofort ersichtlich, ob eine Schweissstelle vergessen wurde oder nicht.



  Der Farbindikator kann z. B. einen weissen Punkt 11 aufweisen, der bei   zunehmender    Temperatur dunkler wird und sich bei Erreichen der Endtemperatur von etwa 2400 bis 2500 C schwarz   verftirbt   

**WARNUNG** Ende DESC Feld konnte Anfang CLMS uberlappen**.



   



  
 



     PATENT CLAIMS
1. Electrically heatable welding sleeve made of thermoplastic material for connecting plastic pipes with heating wire winding housed in the sleeve, the ends of which are filinted to the outside for connection to a power source, characterized in that a temperature indicator (10) which changes color when the temperature increases is arranged on the sleeve.



   2. Welding sleeve according to claim 1, characterized in that the temperature indicator (10) made of paper or plastic is glued onto the sleeve next to the connection sockets (7).



   3. Welding sleeve according to claim 1, characterized in that the temperature indicator has a colored point (11) which changes color permanently when the temperature increases.



   The invention relates to an electrically heatable welding sleeve made of thermoplastic material for connecting plastic pipes with heating wire winding housed in the sleeve, the ends of which are led to the outside for the purpose of connection to a current queue.



   Such welding sleeves have led to a great rationalization in the production of plastic pipe connections.



   When assembling pipe systems, it is advisable to loosely assemble the individual pipe sections and sleeves in order to be welded together in groups.



  Each time it is necessary to check which connections have already been welded and which are still to be welded. Since known sleeves do not differ externally before and after welding, this test is carried out manually, which is disadvantageous.



   However, it can also happen that the welding of individual connections is forgotten in a large pipe system or that the necessary temperature for a perfect weld, e.g. B. as a result of a brief power failure, is not achieved. Finally, as a result of the craftsman's inattentiveness, welding sleeves were connected twice to the power source, which led to a weakening of the connection.



   The object of the invention is therefore to create a welding sleeve of the type mentioned at the outset, in which a simple visual inspection can be used to check whether the welding has already taken place and whether the correct welding temperature has been reached or not.



     According to the invention, this is achieved in such a way that a temperature indicator which changes color when the temperature rises is arranged on the sleeve.



   An exemplary embodiment of a welding socket is explained in more detail below with reference to the drawing. Show it:
1 shows a longitudinal section through a welding socket, and
FIG. 2 shows a partial view of the welding socket according to FIG. 1 in the area of the connection socket, from the front side.



   The electrically heatable welding sleeve shown in FIG. 1 has a cylindrical body 1 made of a thermoplastic material, for example polyethylene. The inner wall 2 of the body is provided with a helical groove 3 into which the winding 4 of a heating wire is inserted. The ends of the heating wire are led to the outside through two radial bores 5 and are connected to two Koataktstiicken 6 anchored in the body, which in turn are shielded by two sockets 7.



   The pipes 8 indicated by dashed lines in FIG. 1 are pushed into the socket on both sides up to the stop ring 9.



  The sleeve is then heated in a known manner by the heating wire 4, which causes it to shrink and the inner wall to be welded to the pipe ends.



     To check that the welding has been carried out correctly, a heating indicator 10 is arranged on the sleeve. This indicator 10, which is known per se, for example made of paper or plastic, is expediently glued onto the sleeve in a clearly visible manner next to the sockets 7, the gluing point must be absolutely free of grease. The permanent discoloration of the indicator after welding the socket can be used to determine whether the correct welding temperature has been reached.



   Since when assembling pipe systems, the individual pipe sections and sleeves are usually loosely joined together to be welded together in groups, the indicator can be used to determine immediately which connections have already been welded and which are still to be welded. In this way, disadvantageous double welds can be avoided, and it is also immediately apparent whether a weld has been forgotten or not.



  The color indicator can e.g. B. have a white point 11 which becomes darker with increasing temperature and turns black when the final temperature of about 2400 to 2500 C is reached

** WARNING ** End of DESC field could overlap beginning of CLMS **.

Claims

** WARNING ** Beginning of CLMS field could overlap end of DESC **.

PATENT CLAIMS 1. Electrically heatable welding sleeve made of thermoplastic material for connecting plastic pipes with heating wire winding housed in the sleeve, the ends of which are filinted to the outside for connection to a power source, characterized in that a temperature indicator (10) which changes color when the temperature increases is arranged on the sleeve.

2. Welding sleeve according to claim 1, characterized in that the temperature indicator (10) made of paper or plastic is glued onto the sleeve next to the connection sockets (7).

3. Welding sleeve according to claim 1, characterized in that the temperature indicator has a colored point (11) which changes color permanently when the temperature increases.

The invention relates to an electrically heatable welding sleeve made of thermoplastic material for connecting plastic pipes with heating wire winding housed in the sleeve, the ends of which are led to the outside for the purpose of connection to a current queue.

Such welding sleeves have led to a great rationalization in the production of plastic pipe connections.

When assembling pipe systems, it is advisable to loosely assemble the individual pipe sections and sleeves in order to be welded together in groups.

Each time it is necessary to check which connections have already been welded and which are still to be welded. Since known sleeves do not differ externally before and after welding, this test is carried out manually, which is disadvantageous.

However, it can also happen that the welding of individual connections is forgotten in a large pipe system or that the necessary temperature for a perfect weld, e.g. B. as a result of a brief power failure, is not achieved. Finally, as a result of the craftsman's inattentiveness, welding sleeves were connected twice to the power source, which led to a weakening of the connection.

The object of the invention is therefore to create a welding sleeve of the type mentioned at the outset, in which a simple visual inspection can be used to check whether the welding has already taken place and whether the correct welding temperature has been reached or not.

According to the invention, this is achieved in such a way that a temperature indicator which changes color when the temperature rises is arranged on the sleeve.

An exemplary embodiment of a welding socket is explained in more detail below with reference to the drawing. Show it: 1 shows a longitudinal section through a welding socket, and FIG. 2 shows a partial view of the welding socket according to FIG. 1 in the area of the connection socket, from the front side.

The electrically heatable welding sleeve shown in FIG. 1 has a cylindrical body 1 made of a thermoplastic material, for example polyethylene. The inner wall 2 of the body is provided with a helical groove 3 into which the winding 4 of a heating wire is inserted. The ends of the heating wire are led to the outside through two radial bores 5 and are connected to two Koataktstiicken 6 anchored in the body, which in turn are shielded by two sockets 7.

The pipes 8 indicated by dashed lines in FIG. 1 are pushed into the socket on both sides up to the stop ring 9.

The sleeve is then heated in a known manner by the heating wire 4, which causes it to shrink and the inner wall to be welded to the pipe ends.

To check that the welding has been carried out correctly, a heating indicator 10 is arranged on the sleeve. This indicator 10, which is known per se, for example made of paper or plastic, is expediently glued onto the sleeve in a clearly visible manner next to the sockets 7, the gluing point must be absolutely free of grease. The permanent discoloration of the indicator after welding the socket can be used to determine whether the correct welding temperature has been reached.

Since when assembling pipe systems, the individual pipe sections and sleeves are usually loosely joined together to be welded together in groups, the indicator can be used to determine immediately which connections have already been welded and which are still to be welded. In this way, disadvantageous double welds can be avoided, and it is also immediately apparent whether a weld has been forgotten or not.

The color indicator can e.g. B. have a white point 11 which becomes darker with increasing temperature and turns black when the final temperature of about 2400 to 2500 C is reached