July 1, 1919.] 



THE INDIA RUBBER WORLD 



553 



REBUILDING. 



The body of the old tire, after removal of the tread and first 

 ply of fabric, is examined and if there are any blow-outs or 

 weak places in it. these are stripped off as for an ordinary section- 

 al repair. 



Stitchtxg Down the Tread. 



The tire then goes to the building-up department, where it 

 receives two coats of good vulcanizing cement and is allowed to 

 dry, after which the blow-outs and weak places are repaired with 

 reclaimed tire fabric. Any repairs made on the inside of the tire 

 are made on the bias, giving the ends of the repair fabric the ap- 

 pearance of an ordinary splice. The tire is then mounted on a 

 collapsible core, and one ply of reclaimed fabric is applied on 

 the outside to replace that removed with the old tread. The 

 cushion gum, bead fabric, breaker fabric and tread gum, all of 

 new material, are then applied in the same manner as in building 

 a new tire. 



CURING. 



The tire is now ready for curing in an adjustable tire mold. An 

 air-bag is inserted in the tire and it is placed in the mold, the 

 upper half is lowered to the proper place, the air-bag inflated to 

 150 pounds pressure and steam turned into the jacketed mold. 

 After a cure of fifty minutes at sixty to sixty-five pounds the 

 steam is turned off and water is circulated through the molds Ui 

 cool them. The upper half is then raised and the tire is taken 

 out. The air-bag is removed and the slight over-flow at the 



edge of the tread trimmed off with a small V-shaped push-knife. 

 The tire is then finished with a coating of talc. 



Different brands of tires vary in size, one make will measure 

 654 inches from bead to bead, while another brand of the same 



size will measure 7 or 7}/2 inches from bead to bead. Therefore, 

 adjustable tire molds are made that give a perfect cure on either 

 a full or scant size tire of a given size. In curing by the open- 

 steam, wrappe I systems this variation in the size of tires is easily 

 overcome, but in the mold cure, the tire must fit the mold 

 or it will not be perfect. If the tire is too large, it will be 

 wrinkled or mold-pinched ; if too small to fill out the mold there 

 will be insufficient pressure on the tread. 



Th: adjustable mold is made in two pieces — the lower part 

 curing one side and the tread, while the upper part fits down into 

 the lower and cures the opposite side of the tire, a complete cure 

 being effected in one operation. In curing a scant size tire, the 

 mold is closed completely, while on a full size tire it is left 

 slightly open. Both the upper and lower cavities contain live 

 steam, but valves may be installed in the steam line, so as to 

 cut off the steam in either cavity for curing one side of the tire 

 only, as in the case of a large rim-cut or side-wall repair. 

 {To be continued.) 



ROAD BUILDING AND TIRE BUILDING. 



A COMPARISON of American road building and motor vehicle 

 ■'»■ production during the past nine years vividly shows the 

 necessity of enormous highway expansion. In 1910 approxi- 

 mately 7 per cent of this country's highways were improved, 

 and even to-day improved 

 roads are estimated at only 

 IS per cent of the total 

 mileage. But while good 

 roads were being "doubled, 

 the number of automobiles 

 has been increased some 

 seventeen times. Within 

 five years the main traveled 

 roads will be clogged with 

 trafiic, and in figuring high- 

 way capacities and building 

 new roads the ratio of in- 

 creasing traffic must be con- 

 sidered. 



Highway building is mak- 

 ing great progress to be 

 sure, but it is only in its 

 infancy, and when the ex- 

 penditures now authorized 

 by the several States and 

 the Federal Government 

 have been exhausted the 

 work w'ill be only fairly 

 under way and tremendous 

 further outlays will be re- 

 quired. More has been ac- 

 complished in the Eastern 

 States than elsewhere, but 

 the Middle West and even 

 the South are rapidly 

 awakening to the need. It i? 

 probable that the people of 

 thirteen States will have 

 voted in favor of bond issues aggregating more than half a billion 

 dollars for better highways before next winter. Illinois, Penn- 

 sylvania, Michigan and Utah have already authorized issues 

 amounting to $162,000,000, while the legislatures of Montana. 

 Oklahoma, Alabama, California, Missouri, Georgia, Minnesota, 

 Texas and West Virginia have recommended that the people vote 

 this year for good roads appropriations totaling $371,000,000. 

 The overwhelming vote in the first four States mentioned 

 seems to indicate a successful outcome in the other nine, and 



The tot.-il roa.I mile: 

 States is about 2,456, 

 a total registration o 

 vehicles there is an a 



registr 



of the United 



I miles. With 



,146,617 motor 



an average of 2.5 mo- 



f mile of public road. 



the United States, California and Ne- 

 braska average one c; 

 persons. Iowa and S. 

 to 8. Alabama. I to 5: 





