April 1, 1921 



THE INDIA RUBBER WORLD 



501 



attached edges, whereas at ordinary room temperatures the rubber 

 would cut with rough edges fused together. 



DEVICE FOR SEJ'ARATING MOISTURE FROM STEAM, GAS AND 

 COMPRESSED AIR 



Many rubber niauuiacturers have found this type of separator 

 gives excellent service in eliminating the moisture from com- 

 pressed air at the point of usage. The 

 separators are installed at proper [wints 

 on the pipe lines and take up no more 

 space than the pipe itself and its flanges. 

 The horizontal, vertical, and angle types 

 are shown herewith. The separators are 

 made of steel plate and built for a work- 

 ing pressure of 200 pounds unless other- 

 wise specified. Companion flanges 

 ■'! and gage glasses are also furnished. 

 .! The steam or compressed air, when 



passing through the separator, is 

 caused to revolve around the spiral 

 many times. Any foreign matter 

 that is heavier than the steam is 

 thrown outward by centrifugal force, 

 where it is acted on over and over 

 again. The denser portion is re- 

 peatedly shaved off by the overlap- 

 ping edge of the slotted opening shown in the cross-section. The 

 water or other matter thus separated is delivered into the col- 

 lecting chamber below, where it is entirely isolated and cannot 



Veriic.kl .\nd Angle 

 Sep.\r.\tor 



Av>\?^\y^^\vl^5 



Horizontal Separ.\tor 



be picked up again and carried along by the currents of steam. 

 The steam passes through easily without obstruction and with- 

 out loss of pressure. — United Machine & Manufacturing Co., 

 Canton, Ohio. 



MACHINERY PATENTS 

 VACUUM PROCESS OF MOLDING HOLLOW RUBBER GOODS 



IN THE MAXfFACTURE of hollow rubber articles, like nipples, 

 syringe bulbs, hot water bottles, football bladders, inner tubes 

 for pneumatic tires and so forth, the rubber sheets are seated by 

 vacuum in two sets of mold dies or cavities. The sheets are 

 brought together to form a peripheral seam which encloses an 

 interposed mandrel or permanent hollow stem. At the same time 

 the sheet is cut to the desired shape by knife edges extending 

 around the mold cavities. 



Figs. A and B apply to nursing nipples. A rubber sheet is 

 seated on each mold plate and is drawn into the mold cavities by 

 vacuum. The clamping grooves and the cavities are both in con- 

 nection with the chambers to which vacuum is applied. A set 

 of mandrels carried by a bar is then placed in position and the 

 mold plates are forced together. Knife edges running around the 

 interior of the mold and extending to meet the mandrels, .sever 

 the sheets and force together the severed edges, at the same time 

 pressing the rubber into the grooves provided to form the beaded 

 edge of the nipple. The mandrel carrying the partially formed 

 nipples is then removed to the vulcanizing chamljer. 



Another method, slightly different in application is shown by 

 Fig. C. Here the nipples are formed end to end and the con- 

 necting part of the mandrel is slightly enlarged in order to force 

 the rubber into the bead grooves and at the same time to make 

 the waste portion relatively thin. In vulcanizing this form, the 

 seam produced by molding, is placed out of the plane of the vul- 

 canizJng mold plates, see Fig. D. Still another manner of making 

 the double nipple is illustrated by Fig. E. A cylindrical- mandrel 

 with a central collar is employed and the vulcanizing mold cavi- 

 ties are formed perpendicularly to the faces of the mold plates, 

 thus avoiding any external scam and obviating the need for the 

 waste piece. The nipple end is expanded for vulcanization by 



Various Molds for Hollow Ribber Goods 



water, etc., enclosed prior to molding, the pressure being trans- 

 mitted by passages indicated by tlie dotted lines shown in the 

 illustration E. 



Fig. F relates to syringe bulbs. The mandrel is entirely en- 

 closed. After vulcanization, it is reinoved by cutting off the 

 ends of the necks. The humps prevent undue stretching of the 

 rubber when drawn into the cavity. Fig. G pertains to hot water 

 bottles. In addition to the main mold cavity there is a half- 

 conical cavity to take the funnel mandrel, which carries the 

 usual internally threaded ferrule. It is formed with a bevel to 

 act in unison with a semi-circular extension of the knife edge 

 running around the cavity. The rubber sheet is secured over the 

 mold plate prior to being drawn into the cavity by a clamping 

 ring (Figs. G and H) formed with an extension surrounding the 

 funnel. A similar process and apparatus is used for football 

 bladders, etc. A hollow rubber stem, in this case, is vulcanized 

 into the bladder. Both this and the preceding example illustrate 

 the ready applicability of reinforcements such as strips shown in 

 Fig. /, or the tab and neck pieces in Fig. G. These arc placed in 

 pos.ition after the sheet is seated and prior to the closure of the 

 mold. Similarly the necks of the syringe bulb may be rein- 

 forced by a small section of rubber tube carried at each end of 

 the mandrel. 



For inner tubes, Figs. / and K, the molds have inner and miter 

 clamping grooves, inner and outer cutting edges extending radi- 

 ally inwards to sever the portions of sheeting for enclosing the 

 valve stem. Each mold cavity and Likewise the vulcanizing mold, 

 is formed with a hump giving the tube a cross-section as indi- 

 cated in Figs. K and L. On the expansion of the tire cover, the 

 inner and the outer peripheries arc somewhat thicker than the 

 side walls and in addition, insertion is facilitated. Before closing 

 the valve stem Fig. /, reinforcing washers and rings are laid 

 in the groove between the cutting edges. During the vulcaniza- 

 tion, where necessary the articles are kept extended in the mold 

 by pressure supplied through the hollow stem, similar to the 

 valve stem in the case of the inner tube, or by water, ammonia, 

 and other liquids introduced before closing the mold. — Fred T. 

 Roberts, Cleveland, Ohio. U. S. A.. Tulv 8. I9I9: British Patent 

 No. 17085. 



