126 



THE INDIA RUBBER WORLD 



[December 1, 1913. 



feature of any steam hose is its tube or lining, since the tendency 

 of the rubber is to harden or over-vulcanize under the heat. 

 The average hose is vulcanized at a temperature of about 260 

 degrees F., and when we consider that steam under a pressure 

 of 100 pounds creates a temperature of about 338 degrees (at 

 200 pounds the temperature is 388 degrees), the necessity of a 

 special lining can be readily appreciated. Steam hose is con- 

 structed with from four to eight plies of fabric in Yi to 2-inch 

 sizes. If the pressure is more than 70 or 80 pounds per square 

 inch the hose should be reinforced with wire or marhne wrapping. 



Fig. 3. 



The Wkbb Molding M.vchine Oi'kratf.i) With Rubber 

 Hose. 



Where welding is done by means of the oxy-acetylene or other 

 gas process, the torch is attached by means of a rubber hose 

 to the gas tanks in order that it may be manipulated to the 

 best advantage for heating the metal which is being welded. 

 Here again the flexibility of rubber hose not only widens the 

 scope of the new process of welding, but it also makes possible 

 more convenient methods of accomplishing many other kinds of 

 work which were slowly and clumsily done before the advent of 

 the portable heater. On account of the penetrating ability of gas 

 the lining and layers of rubber between the fabric should be very 

 compact and durable. Such hose is usually made only in small 

 sizes, under one inch in diameter, and with three plies of fabric. 



In Fig. 1 is shown one form of a self-contained portable heater 

 in which the attached rubber hose plays an important part. 

 This torch has found a wide use in boiler shop work for shrink- 

 ing, expanding, heating crown sheets, laying patches, drawing 

 blisters, bending plates, etc. The metal coil which covers the 

 hose is principally for protecting it from wear, since the pres- 

 sure in this case is not excessive. Certain types of these heaters 

 or torches, when the ^as mixture is properly controlled, will give 

 a light equal- to more than 1.000-candle power; hence they are 

 often used for night work in places where electric or other 

 lights are not available. 



In the foundry rubber hose is as indispensable as in tlie ma- 

 chine shop, but it is employed chiefly for entirely different pur- 

 poses. Perhaps the most conspicuous use to which rubber is 

 put in connection with foundry work is in its attachment to the 

 sand blast. Ever since the beginning of the industry foundry- 

 men have been confronted with unusual problems pertaining to 

 the cleaning of special castings; but since the introduction of the 

 sand blast many of these problems have proved easy of solution. 

 One form of the modern sand blast, in whicli rubber hose forms 

 an essential part is seen in Fig. 2. The tank portion of the appa- 

 ratus comprises the container for the sand, while the air pressure 

 is introduced through the valve at the side, this valve being con- 

 nected with the source of the air pressure by means of a length 

 of three or four-ply air hose not seen in the illustration. The 

 hose shown connected with the tank conveys the sand under 

 pressure to the outlet, whence it is directed with great force 



against the casting. Tlie workmen can move the nozzle about 

 over the work as portions of the casting are cleaned. The appa- 

 ratus shown herewith will clean from 3 to 5 square feet of steel 

 plate per minute, and as much as ten tons of castings per day, 

 according to the air pressure and the size of the nozzle used. 



Sand blast hose must be of special construction in order to 

 withstand the cutting action of the sand. A solid substance, such 

 as hard-vulcanized rubber or a metal lining cannot be used, since 

 these would be worn away very rapidly. Therefore, a thick lining 

 of soft Para rubber is employed, the lining being almost equal in 

 thickness to the walls of the hose. Such hose rarely comprises 

 more than four plies of fabric, since the erosion resisting qual- 

 ities are more essential than strength. 



Perhaps the hose which is most commonly seen in shops and 

 foundries is fire hose. Where would civilization be today 

 were it not for the introduction of rubber hose in fire fighting 

 apparatus? Of course, hose made of other substances — such as 

 leather — has been tried, but has always proven either too ex- 

 pensive or incapable of standing up under the wear and ex- 

 cessive strain to which they are subjected, Today almost every 

 shop and factory of any size has its private apparatus and a squad 

 of workmen trained to fight fires. 



Another instance of the univefsality of the rubber hose is seen 

 in its application to pneumatic molds and presses, two types of 

 which are illustrated in Figs. 3 and 4. These presses are used 

 for squeezing the molding sand tightly around the pattern so that 

 a good, smooth casting will result. Tlie rubber hose forms an 

 essential part of this device also. It is so arranged that the 

 nozzle or valve at the outlet end may be applied to or removed 

 from the press almost instantly, while the operating lever permits 

 any desired pressure to be brought against the mold. Fig. 4 

 shows the application of the rubber hose in this respect particu- 

 larly well. In this machine the hose is designed to withstand 

 an average pressure of about 80 pounds .ind to deliver about 4 

 cubic feet of free air per minute. In construction, this hose is 

 the same as that used with other pneumatic tools. The advant- 

 ages of this mrichine are many. It relieves the operator of heavj' 



Fig. 4. T.-\bor .Air Pressure Mold ix Operation. 



work and allows him to bend his energy toward greater pro- 

 duction. Absolute uniformity in the density of the sand is ob- 

 tained, by this means, and consequently the loss of castings 



