112 



THE INDIA RUBBER WORLD 



November 1, 1920 



ENGLISH METHOD OF TUBE SPLICING' 



THIS METHOD of spliciiig inner lubes is not only extremely 

 popular in England with all those concerned in tire repair- 

 ing hut is rapidly being taken up by manufacturers as well. 



\ot only is the lapped joint a constant source of weakness in 

 itself, but whenever a puncture occurs near it the very act of 



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putting the repair on the vulcanizer opens the splice and causes 

 further trouble. All this is avoided when a tube is spliced by 

 the present method, which consists in bringing the two ends to- 

 gether and vulcanizing them without lapping. The tube then 

 has an even uniform surface, all parts are equally strong, and 

 the pressure is equally distributed. The tube is in fact endless, 

 because the space between the two ends is filled with vulcanized 



Fig. 2. The Exn.s Beveled 



rubber, which is identical in every way with the tube itself. 



The only way in which a butted joint can be made is to vul- 

 canize the tube while it is circular, and as it would be when in- 

 flated, and this is done on a special splicer. Following are the 

 instructions for making jointless splices. 



Trim both ends of the tube, taking care to press the sides to- 

 gether as_ shown in Fig. 1. This will preserve the curved shape 

 of the tube. 



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Tievel both ends with small shears, giving a good broad bevel, 

 and mark the ends where thev should meet. See dotted line in 

 Fig. 2. 



Fold back one end of the tube for 12 inches and fold back 

 again for 2 inches, making a double fold as in Fig. 3. Press the 



' Trom "The Complete Guide to Tyre Repairing." Harvey Frost & Co., 

 3-imited, London, England. 



tube through the opening at the side of the expanding mandrel, 

 and replace the covering shield. Push the mandrel into the fold- 

 ed part of the tube, as shown by direction of the arrow, until 

 only about J/j-inch of the mandrel remains outside. The correct 

 position is shown in the ne.xt illustration. The wedge-shaped 

 opening in the mandrel must be the part exposed. 



Now bring the other end of the tube over the folded-back por- 

 tion until the two ends almost meet and form a V-shaped groove 

 between them. Care must be taken that the tube is not twisted. 

 See Fig. 4. 



Fit the wedge in the slot and push it until the tube is held 

 tightly "n tbo mandrel. Then rasp the hnvclcd ends. The 



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Fig. 4. iiiiikk F.n'd I\1-;.\I)V to Ijh I'illkh ux l'_\r,\MiKK 



knife-shaped rasp is best used for this operation, and a piece 

 of old rubber should be placed inside to protect the inner part 

 of the tube. This stage is shown in Fig. 5 and the protecting 

 piece of rubber is marked "X." The rasping is an important 

 operation, and should be done thoroughly and carefully. 



Apply two coats of Plastene-Safiu.x, allowing each coat to 

 dry separately. Then remove the protecting piece of rubber and 

 adjust the two ends of the tube until they are 1/16-inch apart, 

 bill in the groove with Plastene as follows : cut a narrow strip 

 of this material and lay it evenly at the bottom of the groove 



Fig. 5. Rasping the Beveled Ends 



all around the splice ; then a slightly wider strip on top, and so 

 on until the place is well tilled. 



The subsequent operations of pressing down, rolling, and trim- 

 ming are the same as in ordinary tube repairs, but care must be 



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taken that the new material is pressed tirmly and evenly to the 

 beveled sides, and that the depth of the new rubber corresponds 

 to the thickness of the tube. -Apply two coats of red paint, al- 



