KK 1. 1915.] 



THE INDIA RUBBER WORLD 



-f^ 



X -y ^ 



ADAMSON'S TREAD MOLD. 



Tire treads are usually vulcanized either in two-part molds 

 or wrapped with strips of cotton cloth. In the former method 

 the gases in the compound are sometimes trapped, causinj,' 

 blisters: while cloth wrapping is expensive. 



.Xdamson's mold provides a support of powdered soapstone 

 or niolder's sand, which surrounds the tread surface of the 

 casing and holds it in shape wliilc ilu- gases are free to escape. 

 ^ Referring to the 



drawing. 1 is a 

 y 3 nu-tal core on 



wliich the cas- 

 ing is built up. 

 and which is 

 hollow to per- 

 mit access of 

 steam through 

 openings 2. The 

 upper and lower 

 / ^ mold sections 3 



" and 4 respect- 



ively have channels j, which lurm the beads 6. the sections 

 being clamped together by bolts /. The lower mold section 4 

 is extended annularly at iV. forming a circular channel that 

 surrounds the tread surface 9. 



In practice the built-up tire shoe is placed between the sec- 

 tions J! and 4, which are then clamped together. This shapes 

 the beads as well as the body of the shoe in the usual manner. 

 TI1C pocket formed by the extensions of the molds is then filled 

 with molder's sand, which is tamped, in the usual manner, 

 and brought flush with the upper edges of the extensions, 

 wlien the mold is ready for the vulcanizer. The sand sur- 

 rounding the tread surface of the shoe will maintain the rub- 

 ber stock — softened by the rise in temperature — against move- 

 ment, while it also permits the escape of any gases liberated 

 in the rubber. [C. F. .Adamson. assignor to United States 

 Rubber Co., United States Patent No. 1,150.922.] 



OTHER INVENTIONS. 



Raymond B. Price lias recently been granted five patents cov- 

 ering processes of vulcanization and methods of making rubber 

 thread and other vulcanized products. Pjrief descriptions follow : 



\ii.CANizATiON With .\ Fnin Medu.vi. — Tires, hose, boots, 

 and shoes are vulcanized in a bath of calcium chloride or other 

 heat transmitting mediums of a fluid nature under the vulcaniz- 

 ing temperature. [United States patent Xo. 1.152.834.] 



Vii.CANizATicN With a Fluid Medh-.m Under Pressure. — 

 Tlie article to be vulcanized is surrounded with a heating medium 

 and the latter subjected to pressure. [United States patent No. 

 1.152.835.] 



X'uLCANiziNG Fabric and Rubber. — A layer or layers of fabric 

 are interposed between layers of rubber such as in hose or tires. 

 The fabric layer is first subjected to fluid pressure and then a 

 greater pressure is applied to the exterior rubber layers. This 

 removes the moisture and compacts tlie layers of fabric and 

 ru).ber. [United States patent No. 1.152,836.] 



Warming, Pre-heating, and Vulcanizing Process.— Boots 

 and shoes are treated to a preliminary warming at or under 

 atmospheric pressure, then to a pre-heating at a temperature 

 above the curing heat and at a pressure above, at, or belou- 

 atmosphere, and finally they are vulcanized. [United States pat- 

 ent No. 1,152,837.] 



Making Rubber Thread. — A number of superimposed layers 

 of rubber sheet are coated with a medium, such as glycerine, 

 that is Ii(iuid at the vulcanizing temperature and the pile is then 

 vulcanized. The coating of glycerine prevents the layers from 

 adhering so that they can be separated after vulcanizing. 

 ILnited States patent No. 1.152,838.] 



Drying Apparatus for Kubiier-Coatkd Fabric? with Recov- 

 ery OF THE Benzine.— The air space above or surrounding a 

 proofed fabric from which solvent is being evaporated is com- 

 pletely enclosed, and facilities are provided for inspecting the 

 fabric after passing the spreading knife. The vapor of the sol- 

 vent is recovered in a closed systetn in which the vapor-laden air 

 is drawn by a fan from the drying chamber through two re- 

 frigerators for condensation ; the residual air being reheated 

 and passing again into the drying chamber. [E. Bataille, French 

 patent Xo. 474,003—1914.] 



A New Waterproof Fabric and Process of Manufacture. — 

 The inventor uses loose staple cotton, hair or threads dis-. 

 tributed in thin layers, the fibers of one or more layers being 

 angularly disposed to the iibers of the adjacent layers. When 

 a sufficient number of layers have been piled together they 

 are submerged in a solution of rubber. After the excess 

 rubber has been pressed out the material is sheeted. 



The claim is made that tires made up of this material are 

 non-skid and puncture proof, and that rubber heels of the 

 material wear longer and will not slip on wet pavements. 

 [Hadwen Swain. United States patent No. 1,152,349.] 



Manufacture of Seamless Goods. — Gloves, nipples, finger 

 cots, tobacco pouches, etc.. are made by dipping. A recent 

 invention covers a process which consists in dipping and vul- 

 canizing separately each successive layer of rubber. The 

 layers may be of different rubbers and consistency, and in 

 making gloves, nipples and finger cots the bead at the open 

 end is formed before curing by rolling up the layer.i. 

 [Thomas W. Miller, assignor to The Faultless Rubber Co.. 

 United Slates patent Xo. 1.152.372. | 



THE GAEDNEa VALVE PACKINJ GRINOEB. 



Hard rubber valves must lie accurately finished to be serv- 

 iceable—that is. the two opposite sides of the ring should be 

 ground fiat and parallel to within two thousandths of an 

 inch. Also rings of the same size should not vary in thick- 

 ness more than five thousandths of an inch. 



The Gardner machine is used for grinding at the same time 

 two parallel sides of a valve or ring. The two abrasive discs 

 are mounted on 

 opposite 1 > 

 placed heads 

 driven by in- 

 dependent belts. 

 The right hand 

 head is fixed 

 and the one on 

 t h e left is 

 moved laterally 

 by a rack and 

 gear operated 

 bj- a hand or 

 foot lever. A 



s t o p - s c r e w. 

 graduated in 

 thousandths ni 

 an inch, rcgii 

 lates the for 

 ward travel oi 

 the head so that 

 duplicate work 

 can be finished 

 accurately. 



In the illustration the g 

 iug. one at a time, \alve: 

 clamped in a simple wo< 

 revolving discs by the rig 

 able head and grinding d 



a lever operated 



der IS shown in operation, unisli- 

 .es of six different sizes. These are 



ooden holder and held between the 

 iglit hand of the operator. The mov- 



disc is brought up against the valve 

 the left hand of the operator. 



