Pipe threading

Abstract

A pipe threading arrangement for connection to a service pipe ( 14 ) in a dwelling comprises a launch coupling ( 50 ) with a body portion ( 51 ) forming a chamber in which a parachute housing ( 60 ) is held. A stopper arrangement ( 30, 31 ) allows the coupling to be attached to the service pipe ( 14 ) whilst gas is present in both the service pipe and main. The housing includes a folded parachute-like device ( 62 ) attached to a line ( 66 ). A front portion of the parachute housing includes flexible guide ( 63 ) which allows the device to be manually lowered into a main pipe via the service pipe. A tube ( 65 ) is used to push the housing through the pipe. The tube is arranged to receive a jet of gas to separate the end with the guide attached and to inflate the parachute into the main where gas flow carries it along the main.

1 . A method of threading a cable between a relatively small bore service pipe at a customer's premises at a first location and a second location on a main pipe, the method comprising providing an access point in the service pipe at the first location and an access point at the second location in the main pipe, providing a retrieval device at the second location, launching a parachute-like device carrying a threading cable from the service pipe, allowing the parachute to move to the second location by means of fluid flow through the main pipe and retrieving the parachute device or the cable attached at the second location to provide pipe threading between the two locations.  
     
     
         2 . A method as claimed in  claim 1  wherein the launch step includes moving the parachute device through the service pipe using guiding means from the access point to a position adjacent a junction with the main pipe prior to launch.  
     
     
         3 . A method as claimed in  claim 1  or  2  including the step of applying a fluid to a closed parachute chamber containing the parachute to open the chamber and to launch the parachute into the flowing fluid in the main pipe.  
     
     
         4 . A method as claimed in  claim 3  wherein the method includes providing a sealable housing for holding the parachute chamber and a pipe stopper device for selectively sealing the service pipe.  
     
     
         5 . A method as claimed in  claim 4  including the step of providing a optical fibre cable for attachment to the threaded cable at the second location and pulling the optical cable through the main pipe into the service pipe.  
     
     
         6 . A method as claimed in  claim 5  including the step of sealing the optical cable in the service pipe by means of a portion of the stopper device.  
     
     
         7 . A method as claimed in any preceding claim including the step of removing a gas meter attached to the service pipe to provide the access point in the service pipe.  
     
     
         8 . A method as claimed in any preceding claim wherein an access point to the second location is provided by forming an aperture in the main pipe and permanently fixing a duct thereto to allow a stopping mechanism and a retrieval mechanism to be utilised to access the main and retrieve the cable.  
     
     
         9 . A method as claimed in  claim 8  including the step of pulling an optical cable via the access point utilising a sealed entry device.  
     
     
         10 . A pipe threading apparatus including means for launching a parachute-like device attached to a cable from a relatively narrow bore service pipe in a dwelling at a first location to a second location in a main pipe under fluid pressure and means for retrieving the cable or parachute at the second location to provide pipe threading between the two locations.  
     
     
         11 . Apparatus as claimed in  claim 10  wherein the launching means includes container means for the parachute and elongate guiding means for assisting the passage of the parachute to a position adjacent a junction with the main pipe prior to launch.  
     
     
         12 . Apparatus as claimed in  claim 11  wherein the elongate guide means is resilient and includes weighted termination means for ensuring the guide means has a tendency to extend downwards.  
     
     
         13 . Apparatus as claimed in  claim 11  or  12  wherein the container means includes a closed parachute chamber and means attached thereto for opening the chamber and releasing the parachute in response to fluid pressure applied to the container.  
     
     
         14 . Apparatus as claimed in  claim 11 ,  12  or  13  including a sealable housing for holding the container means and a pipe stopper device for selectively sealing the service pipe.  
     
     
         15 . Apparatus as claimed in any one of  claims 10  to  14  including housing means attachable to an entry point at the second location in the main pipe, the housing means including means for holding a moveable stopping device and means for holding a moveable retrieval device.  
     
     
         16 . Apparatus as claimed in  claim 15  including seal means attachable to the housing means to allow an optical cable to pass through the entry point in sealed relationship with the housing means.  
     
     
         17 . A pipe threading apparatus for launching a parachute-like device including a closed parachute chamber containing a collapsed parachute, elongate guide means attached to the chamber to assist in moving the chamber through bends in a narrow bore pipe towards a junction with a main pipe and means for applying fluid pressure to the chamber to launch the parachute from the chamber into the main pipe.  
     
     
         18 . Apparatus as claimed in  claim 17  wherein the elongate means is configured to be biased so as to tend to angle downwards.  
     
     
         19 . A method of threading a cable substantially as described herein.  
     
     
         20 . Pipe threading apparatus substantially as described herein with reference to the accompanying drawings.