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THE INDIA RUBBER WOKLD 



INTERNATIONAL DISCUSSION OF CLINCHER AND 

 STRAIGHT-SIDE TIRES. 



\ VERY INTERESTING DISCUSSION between the editor of "Omnia,' 

 •** the well-known French automobile journal, and the tech- 

 nical assistant to the president of the United States Tire Co., re- 

 garding the advantages or disadvantages of the straight-side tire 

 as opposed to the clincher tire, brings out the following points : 



THE FRENCH VIEWPOINT. 



Americans have gone back to rims with detachable side rings, 

 and even split rings which the countries that invented the auto- 

 mobile, with France in the lead, devised in the early days of 

 pneumatic tires but soon found to be wrong in principle and 

 discarded. 



The fundamental fact in this pneumatic tire question is that 

 the -Americans have never been able to attain perfection in the 

 manufacture of soft tire beads. They have never been able fully 

 to obtain that combination of strength and flexibility from which 

 the clincher bead tire derives its true value. They grew impatient 

 and not wishing to experiment, pulled out of the dust of our 

 stock-room the stiff bead, the bead with cables buried in it, and 

 decided to use this type of bead in spite of everything. 



Europeans mount their tires on one-piece rims by stretchinp; 

 their flexible beads over a groove into which the beads slip once 

 they are in place. This is the clincher type. 



Americans do away with the beads, make the sides of their tires 

 straight and vertical, and insert into them non-stretchable steel 

 cables, which makes it necessary first to split the rim and then 

 to reinforce the parts. 



If an American has a break-down, in nine cases out of ten he 

 does not personally try to solve the trouble. He puts his car 

 in a garage and leaves the work to a professional repairman. 



This custom is easy to follow over there for the reason that 

 automobile riding is largely restricted to cities, big suburbs, and 

 highways, where repair shops are abundant. Such a great num- 

 ber of cars necessarily results in a huge number of repair spe- 

 cialists, it is easy to understand that these specialists can afford 

 first-class shop equipment. 



On the other hand, in France the number of automobiles in 

 use is comparatively insignificant — 90.000 in 1919. Motor cars 

 are widely scattered and repairmen are few and far between. 

 For these reasons the solution of tire troubles falls on the driver 

 and the work has to be done on the road. 



This difference of conditions is vital. It constitutes practically 

 the whole problem. 



THE AMERICAN ANSWER. 



The straight-side tire was built because it was felt iliat a 

 ■lore dependable, safe and simple fastening than the hooked bead 

 of the clincher type was needed for heavier cars. For safety 

 and dependability we wanted a tire which could not under any 

 conditions blow out over the rim — one in which the beads did 

 not require a secondary locking device such as lugs, spreaders, 

 etc., to hold them in place once the primary locking device — infla- 

 tion pressure — suddenly vanished through a puncture or blowout. 

 We also sought a combination of bead and rim contour that 

 would not allow the gouging of the tire by the edge of the rim 

 when sudden deflation occurred in service. 



As our development of the straight-side tire progressed, we 

 found that we had introduced not only a more safe, dependable 

 and simple fastening, but also a tire which would deliver consist- 

 ently greater mileage than the best clincher tire we, or any 

 others, could build. In .studying the reasons for this difference, 

 we have come to the conclusion that they lie in the better struc- 

 tural arrangement of the plies of fabric or cord at and above the 

 bead proper and in the larger volume of air carried by the 

 straight-side type. These are the basic reasons and they explain 

 the margin in favor of the straight-side when tires of both types 

 go through a road test without injury. The margin becomes still 

 greater if the tires are run flat even the minimum distance re- 



(juircd to stop the car after a puncture or cut has occurred. 

 Under these conditions the deflated straight-side tire lies naturally 

 over the out-turned flanges of the rim without injury, while the 

 in-turned flanges of the clincher rim cut and chafe many miles 

 out of the clincher tire. Furthermore, the straight-side tire will 

 withstand under-inflation far better than will the clincher. 



It is very easy to catch the tube under the toe of a clincher 

 bead in mounting the tire — something which can not happen to 

 ihe tube in a straight-side tire. Also, unless lugs are used, the 

 tube in a clincher tire can easily be pinched under the beads 

 when the toes of the latter rock as the car takes a curve at speed. 

 In the straight-side type there is no rocking of the beads under 

 any conditions. 



TESTING SHIPPING BOXES. 



IN A TEST for Strength of shipping boxes, the object of which 

 is a simulation of the rough knocks, bumps and jars of 

 handling which a loaded box may encounter in railroad 

 traffic, there has been designed a machine by which the rail- 

 road usage which a box may meet in a 2,000-mile haul can 

 be duplicated in four or five minutes. 



The first machine of this kind — known as the drum box- 

 testing machine — was designed by the United States Government 

 Forest Products Laboratory at Madison, Wisconsin. The 

 results of the box tests made at this laboratory were pub- 

 lished in The India Rvbber World, August 1, 1919. pages 626- 

 628. 





Drum Box-Testing Machine. 



The machine installed at the Mellon Institute, shown here- 

 with, is an improvement over the original tester in that the 

 inconvenience of overhead pulleys and shafting has been 

 done away with by the substitution of a reduction gear for 

 cutting down the motor speed to the drum speed of two 

 revolutions per minute. 



A valuable field of investigation and scientific study of the 

 construction and materials of packages is opened up by the 

 new machine, such as best methods of interior and exterior 

 packing for fragile or irregular shaped objects; the determi- 

 nation of proper specifications for containers carrying various 

 commodities, etc. 



The Container Club of Chicago, an association composed 

 of corrugated and solid fiber box manufacturers of the United 

 States, offers free service in the designing of scientific pack- 

 ing methods for the various commodities capable of being 

 shipped in fiber containers. 



