542 



THE INDIA RUBBER WORLD 



[Ju.. 



artificially increased induction load and wherein the conductor ii 

 insulated with gutta percha or similar material, the dielectric 

 losses are minimized by eliminating or reducing the resinous 

 substances. "Green" gutta percha which contains a small amount 

 of resin may be used alone or may be mixed with gutta perchi 

 or balata to reduce the proportion of resin. Artificial gutta perclia 

 or Gutta Gentcsch, prepared according to Specification 15,255 

 (1899), may also be mixed with gutta percha or used alone. 

 The insulating material may be arranged in several layers, and 

 one or more of the substances, such as resin-freed balata, green 

 gutta percha, Gutta Gentcsch, and gutta percha mixtures, may be 

 used in some or all of the layers. 



[K. W. Wagner, 1 Luisenenstrasse. Lankwitz, Berliii. Germany. 

 British patent No. 1.346 (191SV] 



OTHER PROCESS PATENTS. 



THE UNITED STATES. 

 Method of making vulcanizeii rubber. C. O. Mason. Naugatuck, 



Conn., assignor to The Goodyear's Metallic Rubber Shoe Co.. 



a corporation of Connecticut. 

 \'ulcanized rubber article. C. D. Mason, Naugatuck, Conn.. 



assignor to The Goodyear's Metallic Rubber Shoe Co., a cor- 



Process of making tires. J. R. Gammeter and W. H. Allen, 

 .-Xkrcn, Ohio, assignor to The B. F. Goodrich Co., New York 

 City. 



Method of making tires. T. R. Gammeter, Akron, Ohio, as- 

 signor to. The B. F. Goodrich Co., New York City. 



Process for treating plastic material. R. B. F'rice, New York 

 City, assignor to Rubber Regenerating Co., Mishawaka, Ind. 



Process of testing textiles. H. L. Scott, Providence, R. I. 



1,184,03S. 



1,184,328. Method of making cord 



M. A. Dees, assignor to American 



and S. R. Monroe, executors of 



THE innTED KINGDOM. 



during rubber balls.' A. Schnek, 32 



THE DOMINION OF CANADA. 



Method of manufacturing tires. Morgan & Wright, assignee of 

 E. E. A. G. Mever and G. W. Seiberling— all of Detroit, 

 Mich. 



Process of eliminating porosity from a rubber bottom for a 

 rubber shoe. The Canadian Consolidated Rubber Co., Limited, 

 Montreal, Quebec, Canada, assignee of W. E. Piper, Melrose, 

 Mass. 



RUBBER CALENDER CONTROLLERS. 



""PHE application of electrical apparatus to rubber calender 

 ■*• drives, in practically all cases, requires motors with 4 to 1 

 speed variation and suitable controllers. The speed limit of the 

 motors should be approximately 1,000 revolutions per minute. 

 To meet these requirements the Westinghouse Electric & Manu- 

 facturing Co., East Pittsburgh, Pennsylvania, has developed a 

 line of motors and controllers for rubber calender drives, de- 

 signed for operation on two voltages — 115 and 230 volts direct 

 current. This method has been adopted, due to the fact that 

 electrical equipment for calenders can be made somewhat 

 cheaper if used on a two-voltage circuit rather than a single- 

 voltage circuit, and there is very little difference between the 

 cost of providing either a two-wire or a three-wire circuit. As 

 a matter of fact, in practically all large rubber plants two- 

 voltage, direct-current circuits are used to secure power for 

 the calenders. 



As a rubber calender represents a constant torque applica- 

 tion, a motor of sufficient capacity to provide the required torque 

 at high speed will take care of the power requirements through- 

 out the whole speed range. The motors furnished for calender 

 drives have a two to one speed range by field control. 



The controllers furnished provide approximately a 6 to 1 

 speed variation by means of armature and shunt field control 

 on the two-voltage circuit. They also have a "threading in" 



•Denotes patents for American inventions. 



point which gives a speed of approximately 50 per cent of nor- 

 mal low running speed by means of armature control. This 

 threading in point is used when starting up the calender after 

 it has been stopped. Acceleration is automatic up to the setting 

 of the master switch handle, and is controlled by shunt con- 

 tactors with mechanically interlocked accelerating relays, and 

 by field accelerating relays. Emergency stop with dynamic brak- 

 ing is obtained by a slack cable switch, which can be operated 

 by rope, or by another suitable means, and must be reset by 

 hand. The design of these controllers is such that there is no 

 slump in speed when decelerating from 230 to 115 volts. The op- 

 eration and features of the controllers in brief are as follows : 

 Starting and speed acceleration is obtained by a drum type 

 master switch. A starting push button is also furnished, by 

 means of which the calender can be started and automatically 



accelerated to speed corresponding to the setting of the master 

 switch. One of the line contactors is provided with a back con- 

 tact, which gives dynamic braking on the motor when the cal- 

 ender is shut down, either by means of the slack cable switch 

 or the master controller. This assures stopping of the calender 

 quickly. A two-pole, double-throw knife switch is also provided 

 to permit quick reversing of the calender. The controllers, how- 

 ever, are not designed, nor are they required to operate in the 

 reverse direction. Overload and no-voltage protection is pro- 

 vided. 



The controller shown on the left in the illustration is one for 

 use with motors varying from 75 to 150 horse-power in capac- 

 ity. The line and transfer contactors shown on the bottom 

 panel are of 500-ampere capacity. The accelerating contactors 

 shown on the upper portion of the panel have a capacity of 250 

 amperes. The panel on the right is for use with motors having 

 a capacity of 125 hprse-power and upwards. The main line con- 

 tactors and transfer contactors have a capacity of 1,250 am- 

 peres, and the accelerating contactors are of 500-ampere ca- 

 pacity. 



ARTIFICIAL DAYLIGHT LAMP FOE COLOR WORK. 



Rubber chemists engaged in preparing and matching colored 

 ri'bber stocks will appreciate the Scimatco lamp. 



The annoyance and loss frequently sustained by insufficient or 

 improper illumination, or by delays spent in waiting for sun- 

 light, have been looked upon as necessary evils. The Scimatco 

 artificial daylight lamp has removed completely the risk of these 

 losses and made it possible to ignore the weather and the hour 

 in making color comparisons because the light produced is 

 spectro-scopically identical with daylight. [Scientific Materials 

 Co., Pittsburgh, Pennsylvania.] 



