May I, 1907.] 



THE INDIA RUBBER WORLD 



253 



ROCKWELL DOUBLE CHAMBER FURNACE. 



"T^HE illustration relates to a met^il melting furnace for cop- 

 * per, brass, bronze, aluminum, steel and iron wliich has 

 given special satisfaction in machine shops, including a shop 

 connected with one of the largest rubber factories in the country. 

 In the case referred to, the furnace is used for melting an 

 alum alloy for molds for rubber work. As shown in the illus- 

 tration, this furnace is constructed with two chambers, 

 ranged that they may be used alter- 

 nately. The exhaust heat from the ac- 

 tive or primary chamber goes into the 

 other, thereby simultaneously melting 

 in one chamber and heating the metal 

 in the other to very near the melting 

 point, with one burner and at no addi- 

 tional cost. Besides the economy in- 

 volved, this makes melting practically 

 continuous, permitting melts of various 

 mixtures of metals to follow one an- 

 other in rapid succession. This fur- 

 nace is adapted to oil or gas fuel and 

 the construction is such that there is 

 very little heat lost or radiated. [Rock- 

 well Engineering Co., Xo. 26 Cortlandt 

 street, New York] 



ik-ctric motors that are well laid down, powerful enough for 

 their work, and designed with a reasonable allowance for 

 overload during short periods. More than one machine 

 geared to the same motor may be run independently 

 if desired, and arrangement of friction 

 the machines to be started 



of each 

 clutches 



other, 

 permits 



or stopped 



While One Ch.\meer is Open for Re-Lininc the Other C.\n Be Useu. 



ELECTRIC DRIVES FOR RUBBER MACHINES. 



XTOTHIXG is more trying to the ordinary steam engine drive 

 ^ ' than a load which varies widely, running suddenly from 

 light demands to a high maximum. The London journal Elec- 

 trics recently reported an instance where a rubber masticator 

 run by a steam drive and becoming overloaded, made serious 



Single Ge.\red Rubber }iIixing .\nd Sheeting Machine, Driven 

 Through Flexible Coupling. 



trouble for the whole factory in which it was used. An electric 

 motor, with the perfection in which, and of their connections, 

 they are now made, not only does its work, but can be depended 

 upon to do "tough'' work as well as light. 



Messrs. David Bridge & Co., of 

 Castleton, Manchester. England, 

 have been supplying some rubber 

 machinery on a large scale, adapt- 

 ed for driving with electric mo- 

 tors, which has given thorough 

 satisfaction. The experience has 

 been that though the load on such 

 machines is very irregular, there 

 is no trouble in driving them with 



without shock or jar. There is little power lost, as compared 

 with the loss between a steam engine and various machines with 

 rapidly altering loads. 



The illustration herewith is of a single geared rubber mixing 

 and sheeting machine, electrically operated through a special cut 

 w^orm gearing. The speed of the 20 hp. motor used is 450 

 revolutions per minute. It drives on to the worm gear through 

 a flexible coupling; the worm wheel itself is keyed on to the 

 roller end, and runs at 16 revolutions per minute. It acts as a 

 driver for the front roller as well— a novel arrangement for 

 heavy rubber machinery and one that works satisfactorily. 



It is hardly necessary to say that there is enormous loss of 

 power with mechanical transmission between a steam or other 

 engine and various machines with rapidly altering loads. The 

 electric motor can be designed to tackle that work, not only 

 without fear of breakdown, but with decided economy and 

 efficiency. 



BLACK DIAMOND TOOL POINTS 



■T^HE turning of fountain pen barrels and a great variety of 

 ■'■ other articles made of hard rubber is a branch of the 

 rubber industry that calls for a number of special appliances. 

 There are used in this connection tools pointed with carbon 

 (black diamond), and these points are variously shaped to adapt 

 them to particular uses. The illustrations herewith relate to 

 such carbon points, made by Thomas L. Dickinson, No. 45 Vesey 

 street. New York. These points are used also for turning fiber, 

 celluloid, and other rolls, involving material of a tough, hard or 

 gritty nature, on which a steel tool will not hold its edge and 

 where it is desired to turn out a large number of pieces of uni- 

 form size. 



Carbon (Black Dia.mond) Tool 



