July 1, 1917.; 



THE INDIA RUBBER WORLD 



587 



signal stations simultaneously any desired number of times at 

 brief intervals. As the signals are being transmitted a colored 

 prism pilot light in the central station cabinet indicates to the 

 operator that the system is in operation. 



Signal stations are located in the various departments of the 

 mill and the signals are adapted to be heard under the varying 

 noise conditions. Under ordinary conditions a gong is used. 



while in offices and laboratories the autotone signal is pre- 

 ferred. . When extreme noise precludes a bell, steam or air 

 whistles are substituted, and when air or steam is not available 

 electric horns may be used. 



One of the optional features of the service is the automatic 

 ringing of a special signal, distinctive from the call signals, for 

 starting and stopping work, while another feature provides 

 means for summoning the watchman to the gate wlien the factory 

 is closed. [The Autocall Co., Shelby, Ohio.] 



CEMENT TUBE FILLING AND CLOSING MACHINE, 



\\'hen it is considered that the tool box of almost every motor 

 car, motorcycle and bicycle contains a tube of rubber cement for 

 emergency purposes, it is not diflicult to estimate that millions of 



tlicse little accessories are pro- 

 duced annually. The tubes are 

 tilled with cement at the large end 

 which must be closed and sealed 

 with a special metal clip to pre- 

 \ ent leakage. The filling and clos- 

 ing operation is automatically per- 

 formed on the machine here il- 

 histratcd, wiiicli is used by many 

 of the leading cement manufac- 

 turers. As will be seen, the ma- 

 liiine is mounted on a substantial 

 bed-plate supported by suitable 

 legs, and is driven by belt power 

 or motor drive, if desired, only I4 

 horse power being required. 



The container is designed to 

 carry sufficient air pressure to 

 f^icilitate the flow of the rubber 

 ( rment. This air pressure may be 

 1 ikcn from any source available, 

 but must not exceed 20 pounds 

 jK-r square inch at the receiver on 

 tlie machine. Any pressure less 

 than this may be used, depending 

 ■on the viscosity of the material which is being handled. 



The machine will handle tubes ranging from yi to I'/i inches 

 in diameter and from 2 to 6 inches in length and has a capacity 

 of 25 to 30 tubes i)er minute. It occupies a floor space of 30 by 30 

 inches and weighs 405 pounds. [.Arthur CoUon Co., Detroit, 

 jVIichigan.) 



STAMPED HETAI, RTIBBEa HOLDS. 



The time-worn method of making cast iron or steel molds 

 adapted to the manufacture of hot-water bottles, bulbs and hol- 

 low toys is a matter of considerable expense, particularly when 

 large quantities of goods are produced. While the following 

 process is admittedly tentative and limited in application, the 

 idea is practical and of sufficient suggestive value to make it 

 interesting. 



StaiTiping or drawing plates of soft steel forming a multiplicity 

 of forms by means of dies and hydraulic pressure is a highly 

 specialized branch of mechanical art. The steel maker is called 

 upon to provide special sheet material of different gages, pos- 

 sessing the proper strength and ductility for the cold stamping 

 process. All manner of forms with embossed and engraved sur- 

 faces are accurately reproduced in sheet metal by specially con- 

 structed dies in a hydraulic press. 



For example, the first steps in making stamped hot-water 

 bottle molds would be to construct the dies. This operation 

 will, of course, be costly, but a thousand or more molds may 

 be formed in the press with these dies at a ridiculously small 



cost when compared to 

 that of making the same 

 niimlier of cast iron or 

 steel molds. Two pairs 

 of dies, called a die and 

 force, are made, consist- 

 ing of a male and female 

 die for each half of the 

 mold. Soft steel blanks 

 are forged or otherwise 

 rough-shaped by machin- 

 ing, and by milling and 

 JKUid cutting, two pairs 

 of dies comprising a die 

 and force are made in 

 exact reproduction of 

 each half of the water- 

 liottle and provided with 

 dowel projections and de- 

 pressions for alining the 

 mold parts. The dies 

 arc then case-hardened and fitted to the die press. 



The mold parts are stamped separately from sheets of steel 

 from 1-16 to ]/s inch thick, depending on the character of the 

 mold to be made. The outfit recommended for this work con- 

 sists of a 600-ton hydraulic press connected to a motor-driven 

 four-plunger pump. The press is of the four-column type. 





working at a pressure of 6,000 tons per square inch. The ram 

 has a six-inch stroke and the platens measure 23 by 24 inches, 

 operation of the press being controlled by a hand lever. 



After the stamping operation the up|)er and lower [larts of 

 each mold are assembled and require very little fitting, spring 



