March i, 1906.] 



THE INDIA RUBBER WORLD 



181 



A NEW RUBBER BELT AND ITS MANUFACTURE. 



EVER since rubber came into use as a material for ma- 

 chinery beltinjj, the efforts of manufacturers have 

 been ilirectetl toward the discover}' of some means of 

 counteracting its one objectionable qualitj- — the tend- 

 ency to stretch. This tendency has been overcome to some 

 extent by using a closely woven fabric as a sort of interlin- 

 ing. Although the fal)ric strengthened the belt and reduced 

 the tendency to "give ", the result from its use has not been 

 wholly satisfactory. One objection to the rubber belting has 

 been the liability of the laj-ers of rubber and cloth to sepa- 

 rate. Jlr. William R. Smith, of Buffalo, New York, has 

 invented a belt in wliich he has reversed the relative import- 

 ance of the rubber and fabric. The gripping action of the 

 rubber on the pullej' is retained, but the major portion of 

 the strength and flexibility comes from the fabric. 



It is claimed for the Smith belting that the rubber protects 

 and preserves the fabric, thus adding greatly to the strength 

 of the belt by increasing the cohesion of the fibers. The 

 fabric used differs from that used in the older types of rubber 

 belting, in tliat it is much coarser in mesh. It is not dis- 

 posed in layers, but is a continuous multiple ply woven fab- 

 ric. It is stretched and dried in the making, thus excluding 

 all moisture, and while in this condition it is treated with a 

 rubber composition that is forced into all the pores of the 

 cloth. A more thorough penetration of the rubber into the 

 fabric is assured by the fact that the pores of the latter are 

 larger than in that formerly used, and also by the fabric 

 being absolutely devoid of moisture. By this method the 

 rubber is left soft and adhesive, therebj- improving the fric- 

 tional hold on the pulley. 



Mr. Smith has not only invented a new rubber belting, 

 but he has also devised and patented the machine to make 

 it. It comprises a series of adjustable steam heated rolls be- 

 tween which the solid woven or knitted multiple ply cotton 

 webbing is run. The rolls are positively driven by gears, 

 worm wheels and worms from a single shaft running along 

 the side of the machine. The sets of rolls thoroughly dry 

 and take the stretch out of the webbing, each succeeding set 

 of rolls having greater surface velocity than the preceding 

 set and a corresponding increase in temperature. 



Tlie webbing is tlius prepared for receiving the liquid rub- 

 ber composition which is fed upon it from steam lieated ket- 

 tles or tanks as it pas.ses through the center rolls. These are 

 called the filler rolls and are placed side by side instead of one 

 above the other so as to form a shallow trough between each 

 pair, allowing the liquid composition to be applied to both 

 sides of the fabric. Tlie ends of tlie trough are formed by 

 flanges on one of the rolls in each of the sets, which run in 

 corresponding grooves in the mating rolls. In each set of 

 the filler rolls, the speed is still further increased to keep the 

 belt stretched throughout its course through the machine. 

 The rolls are built up of rings so that it is possible to change 

 the distance between the flanges which form the ends of the 

 troughs to accommodate various widths of belt. The thick- 

 ness of the belt is determined by the distance between the 

 rolls of each set, which is adjustable. 



After passing through two sets of filler rolls and being 

 thoroughly saturated and coated with the liquid rubber, the 

 belt passes between the heated rubbing plates which have 

 opposed reciprocating motions and serve to further force the 

 filling composition into the fabric as well as to smooth and 

 burnish the surface. The plates are actuated by slotted 

 leaves pivoted betw'een the planes of the plates and driven at 

 their lower ends by eccentrics. In going through the rub- 

 bing plates the rubber in tlie fabric is sufficiently vulcanized 

 w-ithout destroying its pliability and adhesive quality. 



The webbing is drawm into the machine from a reel which 

 is provided near one end with a flange to guide one edge of 

 the roll. Its rotation is retarded bj' a friction brake, the 

 tension of which may be regulated. The completed belt as 

 it is delivered from the machine passes over a guide roll and 

 is coiled upon a winding reel which is provided with a vari- 

 able speed drive to decrease the speed of the rotation as the 

 belt accumulates on the reel. A disk on the side of the reel 

 guides the belt on its inner face and is driven on its outer 

 face by a friction roller which is feathered on its driving 

 shaft so that its distance from the center of the disk may be 

 varied by a rock arm extending down to the floor, to which 

 is connected a similar arm that bears yieldingly against the 



Fig. l.^\'ie\v from the Working Side of llie Smith Fabric Treating Machine. 



THE NEW RUBBER BELT MAKING MACHINE, 



Fig. 2. — Rear View of Ihe Machine as it Appears in the BufTalo Weaving and 

 Belt Co.'s Works. 



