268 



THE INDIA RUBBER WORLD 



[February 1, 1917. 



The spreader brush is set up at the end of a spreading machine 

 and is driven by chain gearing from the main drive. Its province 

 is to dust the starch from the rubhcri-pf! fn'-r-'-- n= it passes 



from the spreader to the wind-up roller. The.'^e brushes are made 

 with soft bristles, about 8 inches in diameter and 48 to 70 inches 

 long, depending on the width of the spreader. 



There are, of course, other brushes that are included in the 

 general list of factory supplies, but the foregoing types are of 

 greater importance and therefore more interesting. [The Osborn 

 Manufacturing Co., Cleveland, Ohio.] 



THE ANDERSON FLOAT-TYPE STEAM TRAP. 



The successful operation of vacuum chamber dryers, vacuum 

 rotary dryers and fabric dryers used by rubber manufacturers 

 and reclaimers for drying rubber and fabrics depends in great 

 measure upon the efficiency of steam traps. A float trap, which 

 has a greater capacity than is actually needed in order to take 

 . ._ care of any variation, is 



usually specified. It is, more- 

 iiver, advisable and almost 

 necessary to have an individ- 

 ual trap on the steam line 

 from each separate dryer ; 

 otherwise there will be back- 

 pressure and the condensa- 

 tion will not drain properly. 

 The heating element in 

 vacuum chamber dryers, used 

 ■"■'■ in this country and abroad 



for drying rubber as it comes 

 from tne w.Mi.i=, co..=i=ts of hollow steel shelves. Steam passes 

 into these shelves, and if any steam is condensed the water 

 must be properly drained in order to make every square mch of 

 the heating surface effective and to insure maximum and uniform 

 drying of the rubber. Tlie steam trap is placed underneath the 

 dryer and connected with a special header that communicates 

 with each of the shelves and drains any condensation that may 

 collect. 



Vacuum rotary dryers are used throughout the world for 

 drying reclaimed rubber. They have a steam jacket in the outer 

 shell, and concentric with a hollow revolving drum, also steam 

 heated. A trap is provided for the steam jacket and a hollow 

 shaft to remove the condensation. 



Special fabric dryers are equipped with individual traps which 

 operate in practically the same manner as those described in 

 connection with vacuum chamber dryers. 



The trap shown in the accompanying illustration is a typical 

 float trap that is well and favorably known to the rubber trade. 

 Its operation, briefly described, is as follows : 



The condensed water enters the trap at the point marked 

 "Inlet" and when sufficient accumulates to seal the valve with at 

 least three or more inches of water, the float then raises and 

 opens the valve, allowing the condensed water to escape at just 

 the right rate to take care of the amount entering the trap, thus 

 maintaining a water seal at all times. 



After the trap has been in use a short time it is advisable, 

 especially on new piping, to remove the sediment strainer and 

 remove the accumulation of scale and chips. 



The trap may be , connected to several dryers with good 

 results, provided a uniform steam pressure is maintained at all 

 times. It is always advisable when making up a connection of 



this kind to run the several drips into a large header and attach 

 the trap to the header, which has the effect of equalizing the 

 pressure to a certain degree and produces better results. 



When the pressure varies to any extent in the dryers the one 

 having the highest pressure will discharge freely and back up 

 into those having a lower pressure, and the best results can be 

 obtained only by attaching separate traps to those having lower 

 pressure. 



A very common trouble with steam traps is caused by low 

 places or pockets in the piping system. Water accumulates in 

 the low spots and is forced through into the trap at intervals, 

 causing an uneven discharge. Where the quantity of accumulated 

 water is sufficient and the steam valve in the line is opened 

 suddenly this water is forced through the pipes at such a high 

 velocity as to cause a water hammer which is very destructive 

 to the whole piping system. [The V. D. .Anderson Co., Cleve- 

 land, Ohio.] 



MOTOR-DaiVEN TEST-PIECE GRINDER. 



In making tensile strength tests of the rubber or fabric ma- 

 terials that are used in the construction of tires, hose, belting, 

 etc.. the sample should he absolutely uniform in cross section. 



This is usually done on a small bench grinder with an abrasive 

 wheel. The original machine of this type, designed primarily 

 for grinding hose-lining test-pieces, was illustrated and described 

 in The Indi.\ Rubber ^\'oRLD December 1, 1914. 



The latest machine, shown in the accompanying illustration, 

 has been improved to meet the requirements of modern rubber 

 laboratory practice. The machine is direct connected to a 

 J4-horse-power electric motor and mounted on a continuous bed 

 plate. The ends of the test-piece are clamped by eccentric rollers 

 that hold the strip firmly against the platen. The platen is pro- 

 vided with hand-operated screws for vertical and transverse ad- 

 justments. The test-piece is ground by moving the platen 

 longitudinally under the revolving emery wheel by means of the 

 projecting handle and it is moved transversely by the cross feed 

 handle shown in the illustration. [Emerson Apparatus Co., 

 Boston, Massachusetts.] 



TIRE MOLD AND CORE CLEANING MACHTNES. 



The mechanical progress that is being made in tire building 

 follows closely the increasing demand for greater production of 

 automobile tires. The hand labor of yesterday is rapidly be- 

 coming eliminated by modern time-saving machinery. The old, 

 laborious method of cleaning tire molds and cores by hand may 

 be superseded by the ingenious machines here shown. 



Referring to the drawing, the base A supports the table B, 

 on which rests the mold C that is to be cleaned. The table 



