904 



THE INDIA RUBBER WORLD 



September 1, 1921 



and one weft-guide, and a different weft-guide is required for 

 everj- change in the diameter of the fabric jacket, or in the num- 

 ber of picks ( layers) of weft per inch of weave. 



MOTOR-DRIVE 



Standard motor-drive equipment is illustrated in Fig. S and 

 comprises a motor and starter 

 mounted upon a special ele- 

 vated support which keeps 

 them clear of dust and fluff. 

 Pulleys are provided for the 

 motor, and for the main 

 driving shaft, together with 

 a special endless belt. The 

 motor is adjustable vertically 

 upon its bracket through a 

 sufficient range to provide 

 for maintaining a suitable belt 

 tension at all times. E.xperi- 

 ence has shown that for ordi- 

 nary requirements, a five- 

 horse-power motor affords 

 ample power to operate the 

 larger and a three horse- 

 power motor to operate the 

 smaller type of circular looms. 



FRICTION CLUTCH AND 

 BAND BRAKE 



A friction clutch is con- 

 tained within the main driv- 

 ing pulley for transmitting 

 the power of the motor, and 

 a band brake is attached to 

 the vertical driving shaft of 

 the loom just above its bevel 

 gear connection. The same 



lever in its opposite motion FiG. S. \'akiable-Speei) Motcr- 

 relea'ses the brake and throws Drive 



in the clutch. The brake 



action will bring the loom instantly from full speed to a dead 

 stop. 



METHOD OF WEAVING 



In a woven tubular fabric the "warp" constitutes the longi- 

 tudinal element and the "weft" or "filling" the circular element. 

 Fig. 1 shows the warp contained in the original spools or "cops" 

 upon a supporting framework called the "creel." It is led from 

 there to the "tension rolls" and "heddle" sections which encircle 

 the outer edge of the loom. It is divided at the heddle sections 

 into two "sheds" which converge toward the weaving point at 

 the center of the loom. 



The filling is delivered from two shuttles, each carrying a 

 closely and specially wound cop of yarn. The two shuttles move 

 at the same time around a circular track within the heddle struc- 

 ture, both traveling in the same direction at the same rate of 

 speed, and at diametrically opposite points on the track. As the 

 shuttles travel around their track, the two sheds of warp issuing 

 from each heddle section are made to reverse their relative po- 

 sitions, vertically, during the interval between the passage of the 

 shuttles. Thus there is continuous rising and falling of heddle 

 sections, in succession, around the circumference (jf the loom and 

 continuous circular travel of the shuttles as long as the loom is 

 in operation. 



The interlocking, or weaving, of the warp and weft into the 

 form of a fabric tube takes place at the center of the loom, around 

 a "weaving pin," or "guider" as the case may be, of diameter 

 corresponding to the size of hose jacket required. .»\s fast as it 

 is woven the jacket is automatically delivered upward by the 

 action of two semi-circular "weft guides," as they lay in the weft 

 around the weaving pin. Final tensioning of the warp threads 



is concentrated at the weaving pin, and this is an important factor 

 in securing a compact fabric. 



By using a tubular weaving pin or guider it is practicable to 

 weave a fabric jacket around steam, air, or garden hose, flexible 

 metallic tubing, electrical cable, etc., or to weave a second fabric 

 jacket over one previously made with the usual type of solid 

 weaving pin. The article to be covered is passed upward from be- 

 neath the loom, through the tubular central coknnii, and the 

 guider, and may be of unlimited length. The weaving operation 

 is continuous so far as the length of product is concerned, but 

 the loom must be stopped at intervals to replenish the supply of 

 filling in the shuttles. 



CRACKING OF RUBBER INSULATION ON IGNITION CABLES 

 In a recent issue of Automotive Industries the results are re- 

 ported of an interesting series of experiments being conducted 

 by the Bureau of Standards for the purpose of finding the causes 

 of the cracking of rubber insulation of ignition cables. 



It has been found that "the cracking at sharp bends, observed 

 in the insulation of high tension ignition wires after service, is 

 due to a chemical attack upon the rubber by the ozone of the 

 electric discharge which takes place at the surface of the cable. 

 This cracking does not occur if the insulating material is not 

 under tension, or if the cable is surrounded by some medium 

 other than air ; but does occur even if the insulation is not sub- 

 jected to electric stress, provided the atmosphere near the cable 

 contains ozone. The extent of this cracking varies greatly with 

 tlif insulating material used." 



The conclusion reached is that the cracking can be materially 

 reduced l)y using braided cable and by avoiding sharp bends. 



Corona on Ignition Cables on 1-inch .-Krbor 



E.xposuRE TO Corona Only Fifteen Minutes at 13,200 Volts A. C. and 



TO Artificial Light 5 Seconds to Show Location of Discharge 

 Upper Mandrel from Left to Right: Kerite Bare, Mineral Rubber. 



Kerite Uncovered 



;>0WER Mandrel from Left to Right: Kerite Bare, Kerite Covered, 



Mineral Rubber 



The experiments referred to are fully described in Technical Note 

 No. 32 of the National Advisory Committee for Aeronautics. 



RUBBER BUTTONS FOR WASHABLE CLOTHING 



H. Craven, manufacturers' agent, Southport, England, has pat- 

 ented a rubber button which is proving particularly satisfactory 

 for underwear, pajamas, flannels, trousers, shirts and all other 

 washable garments. It is made in all sizes and shapes — flat, 

 round, domed, two and four-holes, shank, etc., of either stiff or 

 soft rubber or rubber compound. These also are used as molds 

 to be covered with fabric or other materials. 



