August I. 1916.] 



THE INDIA RUBBER WORLD 



605 



these tires must be pressed on so tightly as to remain m place 

 under severe side thrusts delivered while the vehicle, and con- 

 sequently the wheels also, are subject to considerable vibration, 

 which naturally tends to loosen the band from the felly. 



It will further be noted that in deciding upon the widths of 

 wheel rims, care was taken to arrange for ample safeguard 

 against damage being done to the tire, whenever the wheels run 

 against the curb. In case of flangeless rims, a minimum of 

 10 millimeters [.3937 inch] is to be left projecting at each side of 

 the tire. Where a flange is provided at one side, this allowance 

 is demanded on the opposite edge of the rim. The edge of the 

 rim is tapered to allow easy entry oi the wheel into the tire. 



In order that support may be offered for the steel blocks used 

 when removing the tires, it is recommended that an inturned 

 flange be provided ; failing that, suitable pads or rests, spaced at 

 equal intervals round the rim, would suffice. 



AEROPLANE TIRES.* 



NOW that increased attention is being given to the employ- 

 ment of aeroplanes as aids in national defense, it is inter- 

 esting to note the part that tires play in their use. Aeroplane 

 motors, like automobile motors, must be protected from jolts by 

 pneumatic tires. In the earlier days all sorts of makeshifts were 

 used ; even bicycle tires were pressed into service on some of 

 the pioneer machines. Some builders went so far as to use full 

 size automobile tires. These were equal to the occasion as far 

 as reducing the shock of landing was concerned, but were far 

 too heavy and offered too much wind resistance. 



The old type of aeroplane tire was costly and uncertain. Pres- 

 ent day necessity has compelled tire dependability, as machines 

 are now larger and heavier and must carry more passengers and 

 heavier loads. 



The development of tires to fit the peculiar requirements of 

 the aeroplane began about five years ago. It was early dis- 

 covered that resiliency was an important factor — that a live, 

 springy tire actually aided the machine to get oflf the ground 

 and helped to absorb the shock of landing. Experiments were 

 made with cord construction, with the result that cord tires for 

 aeroplanes have been refined to a point of efficiency equal to that 

 of its successful big brother for electric and gasolene cars. 



On aeroplanes, tires of large cross section are used to pro- 

 vide maximum cushioning ability to resist the lateral thrusts 

 that occur when the machine side-swipes the earth in landing. 

 On machines used for scouting in war, the cross section size 

 is reduced one inch to reduce weight, thereby permitting the 

 carriage of an additional amount of gasolene. 



•By E. R. Pr 



Dept., The Goodyear Tire & Rubber Co. 



THE C0MPHES8I0N INNER TUBE. 



This type of inner tube is designed along new lines of con- 

 struction with the object of avoiding pinching, rim cuts and punc- 



ture troubles. It is extra thick and molded from Upriver fine 

 stock, the diameter being larger in its nor- 

 mal cross section than that of the casing. 

 The first illustration shows the tube in its 

 normal position in the casing, before inflation. 

 When inflated, as shown in the second illus- 

 tration, the excess diameter and molded 

 construction of the tube, it is claimed, pro- 

 duces radial compression that eflfectivcly 

 ?s an ordinary puncture when the object 



is withdrawn. When fully deflated, the tube 



occupies a folded position apparent in the 



illustration that permits a car of ordinary 



weight to run a limited distance on the rim 



without injury to the casing or tube. It is 



said that the heavy walls of the tube re- 

 quire less air pressure and prevent the ma- 

 jority of blow-outs. 



m 



While these tubes 

 are more expensive than the ordinary 

 inner tube, the extra service and im- 

 munity from tire troubles are said, by 

 those who have used them, to be worth 

 the dift'erence in price. [Compression In- 

 ner Tube Co., Louisville, Kentucky..] 



THE PARKER DEMOUNTABLE RIM AND WHEEL. 



Two patents of interest to the rubber tire industry were 

 granted recently to Orrel A. Parker, manager of the Hydraulic 

 Pressed Wheel Co., Cleveland, Ohio. The most important in 

 relation to tires covers 

 a rim that apparently 

 avoids the P e r I m a n 

 claims by providing 

 four simple bolts and 

 two clamps, the former 

 exerting a radial and 

 the latter a lateral pres- 

 sure in attaching the 

 rim to the felly of the 

 wheel. Dowel pins are 

 provided on the rim op- 

 posite the locking de- 

 vices to take the thrust 

 of the drive. 



The second patent provides means for attaching the rim 

 directly to the spokes of an all-metal wheel. In this, the alter- 

 nate spokes are provided with radial locking screws and lateral 

 clips of substantially the same construction as those set forth 

 in the principal patent. 



The illustration shows the application of the Parker demount- 

 able rim to a wooden wheel of the ordinary type. 



KONTHLT TIKE EXPENSE. 



That tire expense is one of the large items in the cost of 

 operating a motor car is generally conceded. But accurate 

 average figures are diflScult to obtain, due to the great variety 

 of cars and the varying conditions under which they are 

 operated. Exact figures, therefore, are interesting. 



Cost Per Month of Opi 

 A 

 51 HP 



Miles traveled 883 



Fuel consumed, gallons 175 



Cost of fuel at 30 cents a gallon $52.50 



Cost of lubricants 2.17 



Tire expense 54.95 



Insurance 17.14 



Storage 40.00 



Supplies, license fees 13.66 



The Automobile Club of America has recently accumulated 

 data on the cost of operating large town cars, shown in the 

 following table, in which the monthly tire expense is given : 



It would seem that these figures are excessive; however, 

 the weight of the cars and the fact that they were driven by 

 chauffeurs must be considered. 



Total $180.42 $168.07 $138.17 $157.12 $119.82 $152.72 



