March 1, 1921 



THE INDIA RUBBER WORLD 



419 



connected by means of a shellac or rubber solution. Such a tire 

 is fastened upon the rim by the use of some adhesive material. 

 The inner rubber tube prevents the flattening of the felt layers. 

 Another methi)d, also of earlier date, provides for a felt band 

 of approximately ten inches in width. This band is wound 

 around a rim by means of a revolving table. When the tire has 

 reached the desired thickness the band is cut and the whole is 

 sewed together with woolen thread so that the different layers 

 cannot get out of position. The tire then is subjected to a 

 felting process, after which it is icturned to another rim, where 

 it is beaten circular by a hamn.ering process. Still hot, it is 

 put upon a third rim. where it is allowed to dry and cool. The 

 outer layers of the tire are impregnated to harden the tire sur- 

 face while the inner layers remain soft so as to give the re- 

 quired elasticity. 



A new method of making the felt tire, shown in Fig. 19, is 

 the follow ing : A cylinder of felt of the diameter required for 

 covering the rim of the wheel is first made. From this cylinder, 

 rings of the desired thickness are cut. These are fashioned 

 upon a turning lathe and impregnated with a waterproof solu- 

 tion. In another construction by the same method the ring ob- 

 tained in the above manner is pressed into tire form, when it is 

 impregnated with a waterproofing solution and covered with a 

 surface of oil or paraffine. In every case only the outer thick- 

 nesses of the tire are impregnated. 



Figs. 20 and 21 show a felt tire in which the individual felt 

 sections f are placed side by side and fastened upon w-ires r. 

 This is an American invention. Fig. 22 is of similar character. 

 The felt sections are made of spirally cut strips of felt which 

 are impregnated with a rubber solution. After drying they are 

 placed side by side and compressed by a strong hydraulic pres- 

 sure. The tire section obtained in this manner is vulcanized and 

 covered with a hardening material. Each section is placed upon 

 a U-rim and fastened by means of a bolt b'. If the tire is to be 

 used upon a flat rim, the whole I'-rim will have to be fastened 

 upon the felloe which is covered for this purpose with a wooden 

 rim h. To prevent the slipping of the U-rim a bolt is inserted 

 through the felloe of the wheel. 



Fig. 23 shows a dual tire which is made by laying strips of 

 felt upon each other f, f and covering the whole with a leather 

 cover /, /'. The felt tires are placed upon an iron rim e, c' which 

 is placed upon the rim base and fastened by bolts b. The tire 

 surface is protected by layers of leather and supported by iron 

 or steel hands. The material is wool felt. Another felt-ribbon 

 tire, Fig. 24, is produced by placing a number of layers of felt 

 upon the wheel surface. The felt strips f in this case are some- 

 what wider than the width of the rim and pressure is applied 

 from the side by means of two side rings r and a screw-bolt b 

 until the width of the tire has been reduced to the w'idth of the 

 rim. An outer iron or steel tire is fastened upon this base, the 

 felt giving elasticity to the structure. The same idea is executed 

 with the aid of two felt tires between which a steel band is 

 introduced to separate the felt strip tires. 



An American patent provides for a piece of felt which is cut 

 in the form of an irregular square. Fig. 25. This is pressed into 

 a circular profile, as shown in Fig. 26, which gives stronger pres- 

 sure to the outer points a, b, c, d and leaves the center k com- 

 paratively soft and elastic. This tire is enclosed in a cover of 

 rubber, leather, canvas or any other suitable material and fastened 

 together on the inner ring. Fig. 27 also shows an inner center 

 of elastic felt which is enclosed in a rubber casing. This casing 

 is vulcanized to the filling material. The ends of the tire are con- 

 nected as shown in Fig. 28. The rim of this tire is of U-shape, 

 which is bent inward when the tire is fi,\cd upon the rim. 

 ■ Fig. 29 shows a dual tire also mounted upon a U-rim. The body 

 of this tire consists of blocks of felt f, f which are placed close 

 together. To secure the blocks upon the rim two iron rings are 



pressed sidewise into the felt over the rim as shown in r. A rather 

 interesting example is that represented in Fig. 30. This is a com- 

 position tire of rubber, cotton and felt. A rubber tube k' is in- 

 serted into another rubber tube k. The inner tube is filled with a 

 center of cotton />. while the space between the inner and outer tube 

 is filled with spirally wound layers of felt a. The cotton filling is 

 intended to prevent the stretching of the tire so that it will stay 

 upon the rim without any special preparation. T-shaped screw- 

 bolts can be used to fasten the tire. These are inserted through the 

 rim. .A new American tire uses thin layers of felt for the body of 

 the tire. These layers are bound together by similar layers made 

 50 per cent of rubber and 25 per cent of gelatine. The individual 

 layers are vulcanized. 



HAIR TIRES 



These are mostly tires of the cushion or bolster type or com- 

 binations of both. Fig. 31 is a tire of the most simple kind. The 

 hair is tightly fastened into a deeply curved rim. The center of the 

 tire, shown in Fig. 32, consists of closely wound hair which is 

 covered by a rubber cover and fastened upon a base which is also 

 made of caoutchouc. The tire is inserted into a U-shaped rim. 



There are several variations of this tire. Thus, the center of the 

 hair covering may be a rubber tube. Or the hair body may be 

 enclosed in a rubber tube. 



Fig. 33 represents a cushion tire where the outer casing is made 

 of rubber which is strengthened on the sides />. The center is filled 

 with carefully pressed hair. In use this tire will flatten out and its 

 heavier sides then will prevent friction from the rim. More elastic 

 is a tire which contains, besides the rubber cover, a center made of 

 rubber. Fig. 34. This tire contains, besides the rubber filling k and 

 the hair cushion It, an air space /. The various sections are sepa- 

 rated by canvas walls and a cover of caoutchouc or leather is iiro- 

 vided. The strong rubber block in this tire retains the tire in its 

 proper position and also supports it if the air chamber should be 

 demolished. The same principle is applied in another tire which 

 contains Iwo compartments, one to be filled with air while the 

 other contains a hair cushion. The bases of these tires may be 

 supplied by a metal insert w-hich takes the place of the air cushion. 



Combination fillings of hair and cork have been tried in this 

 respect and feather fillings also have been used with varying 

 success. 



PAPER AND CARDBOARD TIRES 



The paper and cardboard tires follow in general principle the 

 felt strip and section type of tire. 



Layers of waterproof paper are placed side by side and pressed 

 together by the walls of the rim. The whole is fastened by bolts. 

 Fig, 35 shows such a tire where the body consists of paper layers p, 

 connected with each other by a binding material. To prevent the 

 slipping of this tire the rim is provided with corrugations which 

 grip into similar ones in the tire base. The running surface of 

 this tire is made of rubber or leather, k. 



A French patent, Fig. 36, provides for paper blocks which are 

 connected by tension rings. The whole is placed upon a spiral 

 spring s and a solid bolt is inserted from the sides. A section 

 tire is made of very thin layers of paper which are put upon the 

 rim and are connected by pressure or other means. The same 

 may be effected by making blocks out of the individual pieces 

 of paper. The blocks are provided with wavelike incisions which 

 grip into each other. 



.\ paper band tire is that shown in Fig. 37. A band of paper a 

 is loosely wound around the rim. The running surface b is fast- 

 ened tightly around the paper, which presses it loosely together 

 and brings about the desired elasticity. A soft binding material 

 is inserted between the various layers of paper. Tar, pitch or 

 resin are especially suitable for this purpose. The softness of 

 the binding material, together with the loose adhesion of the 

 paper layers, gives a great elasticity to this tire, which compares 

 well with that of an all-rubber tire. 



