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THE INDIA RUBBER WORLD 



December 1, 1920 



THE WEAVER WHEEL ALINEMENT INDICATOR 



WHEN the wheels of an automobile arc parallel, the wear on 

 the tires is at a minimum since the wheels roll with no 

 friction. Any deviation from this develops a side thrust, or 

 "drag" on the tires that is very destructive. If, for example, the 

 front wheels are out of true one inch, the tires must be dragged 

 sideways three inches in every revolution. Figuring upon this 

 basis, a 30-inch tire would be dragged sideways 168 feet in every 

 mile that the car is driven. 



Statistics show that from tifty to seventy-five per cent of the 

 cars being driven today have their wheels out of alinemcnt to 

 a greater or lesser degree, causing needless wear of tires and 

 costing the motoring public much money. 



To show motorists and garage men easily and convincingly 

 wheel conditions, the Weaver wheel alinement indicator has been 

 created. This instrument will accurately record the misaline- 

 ment of the wheels to the minutest fraction of an inch by simply 

 driving one wheel of the car over it. 



The instrument consists only of two flat steel plates with roller 

 bearings between, the upper plate being accurately connected 

 with a recording mechanism which registers the movement of 

 the plate on the dial. With the portable type, the car owner can 

 run his car slowly over the plate and a glance at the dial will 

 show him the misalinement of the car wheels while the car is 

 in motion or, in other words, the true running alinement which 

 it has heretofore been absolutely impossible to record. 



The larger or stationary type is designed for installing in the 

 runway of the garage so that cars passing in or out will pass 

 over it. This, type is equipped with an electric bell which rings 



Wheel Alinement Device 



if the wheels are out of alinement more than the minimum de- 

 gree which the garage man chooses to establish. Ordinarily, it 

 is considered that three-eighths of an inch misalinement is not 

 serious and the alinement indicator can be set so that the bell 

 will not ring unless the misalinement is more than this or any 

 minimum which the garage man chooses to establish. — The 

 Weaver Manufacturing Co., Springfield, Illinois. 



THE AIR BAG PROBLEM 



THE air bag possibly causes more trouble to the vulcanizer than 

 any other article used in repair work. The average repairman 

 does not stop to consider that the life of an air bag depends 

 entirely upon how it is- used, and consequently it is not given 

 the proper attention and care. This makes it an impossibility 

 to guarantee the air bag for any definite number of cures. 



Before the air bag is used, remove the valve core and inject 

 about one-half pint of water. This can be done by pressing 

 the sides of the air bag together and inserting the stem in a 

 tank or vessel of water, and releasing the pressure. This 



should be repeated about every ten cures, as the water generates- 

 steam, some of which escapes every time the air is released from 

 the bag after a cure. 



The water in the bag keeps the gum tube soft and flexible. 

 It prevents checking and cracking on the inside, which cause 

 a bag to leak. 



It is advisable to have two sets of air bags of each size, one 

 for straight side, and the other for clincher tires. The reason 

 is obvious, as the contours of the two types of casings are 

 entirely different. If the air bag is formed to the straight side 

 tire and then used in a clincher type, it will have to change 

 shape each time. Tliis injures the tube and causes the bag to 

 leak. . 



Another important detail is fitting the bag in the casing. The 

 size given on the outside of the casing does not always determine 

 the size of air bag used. This is especially applicable to cord 

 lires. If the air bag is too small and the ne.xt size is too large, 

 it is better to use a smaller bag and pad it to fill out the casing 

 properly, using one, two or even four plies of fabric if 

 necessary. 



Pads can be made from pulled fabric, and can be used in- 

 definitely. If the bag is too small and not padded to Rt, it 

 will expand beyond its limitations, breaking the fabric or caus- 

 ing it to blow out. This will cause a spong\- or porous cure, and 

 the patch on the tire will wear off prematurely. Padding the air 

 bag to insure a perfect fitting is a very essential part of the 

 operation, if good results are to be expected. The time con- 

 sumed is more than compensated for by the additional number 

 of cures obtained. 



Another air bag abuse is forcing the bag in a casing too 

 small for it. This will cause it to crush or pinch between 

 the beads, breaking the gum tube inside and causing the bag 

 to leak. A bag used in this manner has the appearance of 

 being porous when tested. 



Often the repairman forgets to deflate the bag before releas- 

 ing the clamps. The consequence is a blow-out in the air bag. 

 This is the result of carelessness on the part of the user and not 

 of faulty construction. 



-\ir bags should be inflated to a uniform pressure at all 

 times. If you are using 60-pound pressure in a 3j4-inch bag,^ 

 continue to use the same pressure and depend upon the pads 

 to assist by filling out the casing to proper capacity. If you 

 inflate to an abnormal pressure, it will strain the fabric, caus- 

 ing it to crack and lessening the number of cures. 



Always soapstone the interior of all casings before inserting 

 the air bag, otherwise it will stick and to remove without twist- 

 ing or buckling will be impossible. This will cause it to break 

 at the parts affected. 



.\nothcr suggestion that is important to the repairman is the 

 inadvisability of leaving air bags in a flattened condition. All 

 bags should be inflated after they are used. It is necessary 

 to their longevity to retain their natural shape when not in use. 



Sometimes the repairman adopts the habit of cooling the air 

 bag by throwing it in water. This hardens it and will cause 

 it to crack or break quickly. — Miller Tire Trade .Xczvs. 



"TIRE SAVE" AND "JIFOID" 



"Tire Save" is a putty of about the consistency of bread dough, 

 containing a high grade of Para rubber in its composition, as 

 well as chemicals that produce vulcanization w-ith exposure to- 

 air. F'alchcs applied with "Tire Save," it is claimed, become 

 permanently vulcanized to the tube to which it is aflfixed, 



"Jifoid" is a self-healing cement for plugging leaks and punc- 

 tures in single tube bicycle tires, without the use of either patches 

 or plugs. This cement is put up in both tubes and cans. 



Both "Tire Save" and "Jifoid" are put out by the same manu- 

 facturer. — National Rubber & Specialties Co., Chickering ave- 

 nue and C, H. &• D. Railway, Cincinnati, Ohio. 



