578 



THE INDIA RUBBER WORLD 



[June 1, 1920. 



Stretch and roll the cushion gum thoroughly. 



(14.) Cut two strips of side wall gum to match color when 

 cured, and apply on the side of the side wall, starting just over 

 the bead, bringing it out about the tread line and trim smooth. 



(IS.) Now wash the whole surface where the tread comes 

 down with high-test gasoline to remove dirt, etc. 



(16.) Back up the hole in the tread with cushion gum and 

 pull the tread down to fit snugly in place. Be sure to have a 

 strip of cushion between the splice. 



(17.) Fill in the hole in the tread, also around the splice and 

 where the tread meets the side wall. 



(18.) Stitch, roll and perforate the whole repair well for air 

 vents and trim down smooth. All lay-back sections should be 

 run through a bench tread roller which thoroughly unites the 

 fabric and rubber. 



(19.) Cure. 



REPAIRING A RIM CUT. 



Referring to Figs. 4 and 5, a side section or rim cut repair 

 differs in a lay-back section in that only one side wall is re- 

 moved and the tread is laid back only when the injury extends 

 four or more inches in total length. 



Do not repair a rim cut unless it is an accident. Avoid re- 

 pairing a tire run under-inflated for the chances are it is weak 

 in other places and will soon blow out at some other point be- 

 yond repair. Rim cuts caused by obstacles, curbs, defective 

 rims, etc., can be successfully repaired. 



(1.) Locate the injury. 



(2.) Remove or lay back the side wall two or three inches 

 beyond the end of the injury. If it is at the heel of the bead, 

 it is not necessary to disturb the tread in most cases. If the in- 

 jury is above the heel, a portion should be removed as indicated 

 in Fig. 4, or laid back as previously described. In any event, 

 cut away the side wall or tread on a 45-degree angle to allow 

 more surface for uniting again. 



(,3.) Remove bead strips. 



(4.) Skive edges of injury. 



(5.) Buff removed portion, carrying the buffing well over the 

 repair and bead. 



(6.) The next step is very important, and that is locking the 

 repair in place. 



(7.) Cut the fabric 

 horizontally along the 

 heel of the bead about one 

 inch beyond the injury, 

 then slit the fabric on 

 about a 60-degree angle 

 toward the tread at either 

 end of the injury. See 

 heavy line in Fig. 4. 



(8.) Pry the fabric 

 loose and turn it back as 

 indicated in Fig. 4. 



(9.) The cutting down 

 from the outside being 

 completed, now turn and 

 buflf the tire as previously 

 described. Skive the injury, lift the band ply in the same manner 

 as in operation 7. Now refer to and note operation 8. Cement, 

 select skive shoe, etc. 



(10.) Close up the injury with cushion stock as described in 

 operation 8. 



(11.) Make a pattern of holland cloth that will extend from 

 under the laid-back inside ply to the laid-back outside ply of 

 fabric. When the pattern has been properly fitted, cut the fabric 

 according to the pattern and stitch in place, being careful to 

 stretch the fabric to avoid a bulge after the tire is put in service. 

 Start building up on the inside and be sure the new fabric is as 

 wide as the widest part of the lay-back. 



Fig. S. a Rim^cut Repair. 



Steam 



Pounds.' Degrees 



35 280.6 



40 2867 



(12.) Stitch down the fabric lay-back or wing. 



13.) Insert a three-ply reclaimed shoe, making sure three plies 

 come flush with the toe of the bead. 



(14.) Trim off the portion of the shoe extending over tlie toe 

 of the bead. 



(15.) Finish building up the side wall as heretofore de- 

 scribed in detail. 



CURING SCAI.£. 



The following scale shows the steam pressure and equivalent 

 degrees in F. 



Pressure. 

 Pounds. Degrees F. 



55 302.6 



60 307.3 



65 311.8 



50 298.7 



Tlie time of cure will fluctuate by difference in heat. .\im to work at 

 50 to 55 pounds pressure. 



The above is approximately correct when circulation is en- 

 tirely open, and represents degrees F. of the steam line, and not 

 at the mold. 



The time of cure of the ditferent repairs is in many cases 

 optional with the repair steam man, due to the many makes of 

 vulcanizing plants on the markets and also to the kinds of mate- 

 rials used. It is always advisable for the steam man to take test 

 cures and arrive at curing scales for himself. In fact this is 

 simple, as the different jobs as they come out can be tested with 

 a pencil point and if the impression remains and does not come 

 back to place, a slight amount more of curing will remedy it. 

 Should it be hard or brittle, decrease the cure. 



CITRING SCALE FOR FABRIC AND CORD FABRIC SECTIONAL REPAIRS. 



The following scales have been developed at a large plant 

 using controlled steam at 50 to 55 pounds pressure on standard 

 equipment and can be safely used with the best of results, in 

 any plant with this amount of steam, a slight variation being 

 made to suit the plant in use. 

 Cord 

 Size. Fabric. Fabric. Size. Fabr 



i'A. 



Minuti 



50 



Fabric. 

 Minutes 



50 



4/.. 



Cord 

 Fabric. 



70 



When using an impression pad add 10 to 15 minutes. Cure 

 a fabric tire on the arm about one hour ; cord tire, one hour 

 and fifteen minutes. 



Cure gray tubes for hole repairs 15 to 20 minutes at 50 pounds. 

 Cure red tubes slightly less than gray tubes. Splices and valve 

 pads take about the same time. 



HANDLING HOT CEMENT CLINKER BY RUBBER CONVEYOR 

 BELTING. 

 An unusual problem in handling hot cement clinkers with a 

 temperature of 200 degrees and over was recently solved at the 

 plant of the Standard Portland Cement Co., Leeds, Alabama, by 

 using a rubber conveyor belt. The clinker, however, could not 

 be cooled sufl^ciently to prevent scorching of the belt and its 

 rapid destruction. The answer was found by running the belt at 

 an incline of 12 degrees, so that the lower pulley dipped into a 

 trough of water, thus carrying a film of cold water upon the 

 belt, on which the hot clinker from the loading hopper was 

 deposited. 



The conveyor was made endless by the use of metal belt 

 fasteners which brought the belt ends tightly together, pre- 

 venting the clinker ash from getting into the joint and abrading 

 the belt ends. Moreover, in this method of joining no metal 

 came in contact with the pulleys to cause wear and a permanent 

 joint was thus assured. 



In six months of operation, this conveyor carried 61,000 tons 

 of clinker and credited saving in belt cost alone to this conveyor 

 is $300. The belt used was made particularly to withstand tem- 

 peratures to 200 degrees. ("Chemical and Metallurgical Engi- 

 neering," March 24, 1920.) 



