February 1, 1916.] 



THE INDIA RUBBER WORLD 



227 



is performed in a different set of molds and is therefore another 

 story. 



N()\EL SII.M'I.VC. MUM) KOK TA-XK Hfl-IIS. 



In the making of relatively small hollow riihher articles such 

 as bulbs of various sorts and sizes, the component parts are 

 usually cemented together by hand and finished in molds under 

 pressure. If any defects are developed in goods made in this 

 way the weakness is invariably shown by I)reaks or leaks in the 

 seams. 



That inventive thought and marked nieclianical skill have 

 been brought to bear correctively on these inherent faults in bulb 

 construction, is forcibly shown in the following description of a 

 new tank bulb and the novel molds for making them. 



The old type of flush tank bulb was just an ordinary round 

 hollow rubber ball suspended by a lift rod that was fastened to 

 the ball in any convenient way and was usually inefficient and a 

 constant nuisance. Marked improvements are indisputably pos- 

 sessed by the newest type of tank bulb with the rigid top. In 

 the first place it keeps its shape, for the reason that the up- 

 per half is rigid. Then the lower half is half round and made of 

 good quality soft, flexible rubber that insures a positively water- 

 tight contact between the bulb and valve seat. 



In Fig. 3 will be seen the object in question with the metal 

 reinforcement on the right that imparts rigidity to the upper half 

 of the bulb by being securely vulcanized therein. Then comes the 

 hinged shaping mold — that is shown in the position for filling and 

 emptying by the two following illustrations. Referring first to 

 Fig. 4 will be seen the mold open with the cone plate shaper in 

 front of it. The ball plate shaper is not shown in either illustra- 

 tion as its function will be clearly understood by the description 

 of its use that follows in the context. 



A round disk of suitable diameter is cut from a sheet of reg- 

 ular stock and pressed into the lower mold by the cone shaper. 

 The metal cap then follows, and over this another disk of thin 

 rubber is placed and pressed home by the shaper. thus forming 

 the rigid cone shaped half of the bulb. 



The lower half or ball part is then covered with a round disk 

 of sheeted stock of suitable thickness which is pressed in place 

 by the ball plate shaper. The two mold parts, which in reality 

 are cutting as well as forming dies, are then placed together— 

 the upper and lower halves being aligned by dowel pins— and the 

 whole subjected to hydraulic pressure. In this way the edges are 

 homogeneously united and the bulb, therefore, is made absolutely 

 seamless, a feature, it would seem, that up to the present time is 

 unique in articles of this description. 



Now that this bulb has been satisfactorily shaped there re- 

 mains still the question of getting it safely out of the mold with- 

 out injury, as crude rubber stock is soft and easily damaged. 

 This is accomplished by an ingenious construction of the shaping 

 mold, the two halves of which are divided longitudinally and 

 hinged at one end. Thus by the simple process of opening the 

 mold along its vertical plane the completed bulb is easily removed, 

 as can be clearly seen in Fig. 5. 



SHAPING MOLDS FOR AEROPLANE INNER Tl'I'.ES. 

 Just how far the use of dies and molds can be carried in the ac- 

 tual production of inner tubes for automobiles remains to be 

 seen ; however, the scheme apparently has practical possibilities 

 capable of further development. The following description and 



illustratiuns relate to the forming and vulcanizing of inner tubes 

 used in the tires of aeroplane wheels. 



The molds, or rather dies, are shown in the illi«trations, Fig. 6 

 and Fig 7. In the former the ring core and mold for shaping up 



Fig. 6. Aeroplane Tire Inner 

 Tube Shaping Mold and Core. 



Fig. 7. Aeroplane Tire Inner 

 Tube Press Mold. 



one half of the tube is illustrated, the other half mold not being 

 shown. In practice, the sheeted stock is cut in circular or ring 

 form and laid on the lower shaping mold and upon that the cir- 

 cular core is pressed, thereby shaping up one-half of the tube. 

 The other half is formed by another circle of rubber placed as 

 before in the upper mold half and pressed home by the same 

 circular core that was previously used. 



Now the two halves of the inner tube are in their respective molds, 

 seen in Fig. 7, and ready to be placed together. Before this is done 

 the air valve must be fixed in its proper position. This is care- 

 fully inserted in the cavity provided for it and then the two mold 

 halves, aligned by dowel pins, are placed together and subjected 

 to hydraulic pressure. The result is an absolutely seamless, end- 

 less inner tube being formed by pressure and the action of the 

 edges of the upper and lower shaping molds. The complete inner 

 tube is then removed and placed in special vulcanizing molds in 

 which it is cured by heat and pressure. 



"SIMPLEX" PIPE JOINT CLAMP. 



Pipe joint leaks cost money and often make it necessary to 

 take down the entire line, an expensive procedure when the 

 mill is rushed with orders and working overtime. A handy 

 device that can be quickly applied and one that it is claimed will 

 effectively stop the leak is the "Simplex," which consists of an 

 outside two-part ring, an inside split ring and a square packing 

 ring. To use. the packing ring is first forced against the leaky 

 joint, the inside split ring is next forced against the packing, 

 and the outside ring is bolted around the pipe to prevent slip- 

 ping. [Yarnall-Waring Co., Philadelphia, Pennsylvania.] 



SHALER'S NEWEST REPAIR VULCANIZER. 



A new garage electric vulcanizer with capacity for 200 tubes 

 and 12 casings a day differs from the larger steam vulcanizers 

 in that the heat is generated from the city service by connecting 

 with any lamp socket. [C. A. Shaler Co., Waupun, Wisconsin.] 



ENGLISH SCHOOLS OF REPAIR VULCANIZING. 



The instruction classes held at the City and West End Vul- 

 canizing Schools of Harvey Frost & Co., Limited, London, are 

 intended for those who wish to have actual instruction in the 

 general repair of tires and inner tubes, according to the Harvey 

 Frost process. As the co.st of tuition and materials is con- 

 siderable, a nominal fee is charged, and when the pupil is 

 proficient, he is given a certificate. A certificate can also be 

 obtained by submitting satisfactory repairs executed in accord- 

 ance with the printed instructions issued by the company. The 

 Harvey Frost Diploma of Merit is further granted by the direct- 

 ors of the schools to those pupils who have shown exceptional 

 ability in making repairs. 



