January 1, 1919.] 



THE INDIA RUBBER WORLD 



185 



nference of the casing. 



iing shall be at least 

 three inches apart when measured on the circumterence of the casing. 



(c) All fabric must be square-woven (23 by 23) from Egyptian long- 

 staple cotton or its phvsical equivalent as approved by the Government, 

 weighing 17 "4 ounces to the square yard with an allowable variance of 

 plus or minus 3 per cent. , , . 



(d) ■Ml fabric must be thoroughly dried according to standard manufac- 

 turing practice before it is started through the operations of rubberizing. 



Ce) The usual methods of inspection used by tire companies in com- 

 mercial practice to discover defects in each roll of fabric shall be employed. 

 All fabric shall be tested in an approved testing machine to determine the 

 tensile strength i'n the following manner: the distance between the grips 

 on the machine shall be approximately three 

 of the jaws shall be at the rate of 20 inch« 

 shall be cut from each roll in such a manner 

 sary waste of material. Three samples shall be 

 mine the warp strength and three 

 determine the filler strength^ The 

 lowing manner: unra' 

 one hour and thirty 

 ompleted within thirty secuuus u. i;'_..c_oj^ '.'^"-"r'l.'r',^;';'' 165~pounds 



_s. and the separatio 



minute. Six samples 



eliminate any unneces- 



longitudinally to deter- 



shall be cut transversely to 



shall be prepared 



less tha 



23 yarns (1-inch wi'dth) ; fabric shall be dried 

 inutes at 110 deerees C. Breaking test shall be 

 seconds of time of removing test strip from oven 

 The' results must show a tensile strength of 

 per inch width for either warp or filler. 



(f) Beads shall be constructed with a core 



<g) One chafing strip of 



standard corn- 



used 



n fabric wcighin 

 )n each side of 

 iide of the casing 



f rubber compound 

 breaker. The minii 



of this 



hall be 

 chafing strip sha'll extend upward ( 

 from the channel of the bead. 



(h) There shall be a cushion 

 fabric which shall be wider than t 

 cushion shall be 0.045-inch. . 



(i) Over the cushion there shall be at least one breaker strip of open- 

 weave fabric such as is used in standard commercial practice, coated on 

 both sides with a rubber compound having the physical and chemical proper- 

 tics of a nature to form a perfect union between the cushion and tread 

 when the cure is effected. This breaker strip shall have a minimum width 

 ol 2'A inches Breaker shall be made from long-staple cotton weighing 



"'"(i'rTh;^"trLd"onhrca^ngVan'not be less than 5/16-inch thi.k in 

 the center 's-inch of which shall be the minimum thickness for that part 

 of the tread under the middle of the non-skid portion. 



(k) The sidewall of the casing shall have a minimum thickness of 



''■"/""Thysicai Measurements and Tests, (a) Cross-sectional diameter 

 of each tire inflated according to the recommended weight and load schedule 

 of the S. A. E. shall not be less than 3-7/16 inches. 



(b) Tivcs shall be capable of withstanding water pressure of 300 pounds 

 per square inch without apparent injury. This test is to be made at the 

 disc^retion^of^the_^inspector.^^ union between plies of fabric shall average 

 16 pounds or more per inch, using the standard f "'="<'",'".' ^;^^,J„J'^f'j?f 

 of the casing is to be cut one inch in width, measured circumfcrentially. 

 "'- plies are to be started and pulled down two inches at one bead, which 



^. , ., J ;_ *u^ :.,,..^ r^( cfnnHarH frirtion testing machinc. 



ith the standard 



:o be started 

 bead is to be clamped in 

 The test shall be made on a 

 dead weight friction test. 



y ply 



of separ 



shall not be mo 



d) Strength of the l 

 breaker and cushion 

 standard dead weight 



e) Strength of the u 



le breaker and 

 s than 28 poun 

 above provided 



ad and between 



standard dead weight friction test as 



iidewall and carcass shall be not less 

 standard dead weight friction test as 



the bid 



igs will not be gi' 

 lishes an affidavit 



used 



flat! 

 y tested 



affidavit 



that these cars average at least 1,000 



(h) Tlie speeds, loads, tire size" - 

 such that the casings are properl 

 an inspector to see that the abov 



(c) A bidder must supply an 

 the Government,, stating that the ca: 

 cross-section and practically duplicate, 

 which he has previously tested in acco 

 and a sufficient number of casings sati 

 than 6. have averaged on the rear whc 



6 Lining. The inside of each casi 

 ance with the standard practice of the 



7 Flaps. No flaps shall be suppli 

 8: Compounds, (a) Tread.-The 



the characteristics of a compound containing 

 of the best quality new wild or plantation ri 



The Gov 



ied with. 



ny casings 



e delivering : 

 igs to be delivered 



construction and material, casings 

 ance\vith paragraphs (a) and (b), 

 actcry to the Government, not less 

 s at least 4.000 miles. 

 » shall be properly lined in accord- 

 ire manufacturers. 



ead shall be made from 



Inspection. The Go 



reserves the right to make any inspec- 

 insure the product meeting all require- 



""'lO* Wrapping^'^an'^d 'Siasking. All casings shall be spirally wrapped 

 according to standard practice and properly labeled on the outside showing 

 the size and type, and name of manufacturer A label . with the mon^ 

 and year of manufacture stamped on it shall be pasted in a conspicuous 

 ""Tf.' Packing. Packing shall be as per specifications accompanying tha 

 request for bid. 



PNEUMATIC AUTOMOBILE CASINGS (NON-SKID). 

 Size 31 by 4 inches. 

 fabric construction. 



Specification No. 1063A. 

 November 1, 1918. 

 1. General, (a) Pneumatic automobile casings manufactured in ac- 

 cordance with this specificat 





The 



jfactur 



shall be of fabric construction of the si^e 



load of 815 pounds when 



guarantee them to be free 



from defects in material and workmanship. 



(d) Casings shall be plainly marked with manufactu 

 number and size of tire. 



(e) As soon as [lossible 

 the equivalent metric sizes 



Engineers.^ All casings manufactured in accordance with this specification 

 shall be of the manufacturer's standard non-skid clincher type, designed 

 for the S. A. E. clincher rim of the size 30 by iyi inches. 



3. Construction, (a) Splices on the first ply of fabric shall be gum- 



"''"b^ Carcass of casing shall consist of not less than five nor more than 

 six separate plies of tire fabric, with friction coat on two sides and skim 

 coat on one s.de. The gage of one ply frictioned on two sides and skim- 

 coatcd on one shall be at least 0.045-inch. Each ply shall have not more 

 than two splices which must be at least seven inches apart measured on 

 the circumterence of the casing. The splices in the casing shall be at least 

 three inches apart when measured on the circumference of the casing. 



(c) All fabric must be square-woven (23 by 23) from Egyptian long- 

 staple cotton or its physical equivalent as approved by the Government, 

 weighing 17!4 ounces to the square yard with an allowable variance of 



(d) All fabric must be thoroughly dried according to standard manu- 

 facturing practice before it is started through the operations of rubberizing. 



(e) The usual methods of inspection used bv tire companies in com- 

 mercial practice to discover defects in each roll of fabric shall be employed. 

 ■\11 fabric shall be tested in an approved testing machine to determine the 

 tensile strength in the following manner; the distance between the grips 

 on the machine shall be approximately three inches, and the separati'on of 

 the jaws shall be at the rate of 20 inches per minute. Six samples shall 

 be cut from each roll in such a manner as to eliminate any unnecessary 

 waste of material Three samples shall be cut longitudinally to determine 

 the warp strength and three samples shall be cut transversely to determine 

 the filler strength. The samples shall he prepared in the following manner: 

 unravel to 23 yarns (1-inch width); fabric shall be dried one hour and thirty 

 minutes at 110 degrees C. Breaking test shall be completed within thirty 

 seconds of time of removing test strip from oven. The results must show 



ngth of not less than 165- pounds per inch width for either 



(f) Beads shall be 



ted with 



fille 



standard 



fabric weighing not less than 8 

 ach side of the tire. The chafing 

 f the tire at least 3.^.inch from 



rliafing strip of square-v 

 ounces per square yard shall be used 

 strip shall extend upward on the s 

 the channel of the bead. 



(h) There shall be a cushion of rubber compound applied over the 

 f..bric which shall be wider than the breaker. The minimum gage of this 

 cushion shall be 0.050-inch. 



(i) Over the cushion there shall be at least one breaker strip of open- 

 weave fabric such as is used in standard commercial practice, coated on 

 both sides with a rubber compound having the physical and chemica prop- 

 erties of a nature to form a perfect union between the cushion and tread 

 when the cure is effected. This breaker strip shall have a minimum width 

 of 2^ inches. Breaker shall be made from long-staple cotton weighing 



(j) The 



if the 



ad of 



lall not he less than l^inch thick in the 

 the minimum thickness for that part of 



s'h"a'li"have''l'^'minimum thickness of 0.050- 



id Tests, (a) Cross-sectional diameter 

 he recommended weight and load schedule 



than 4 inches, 

 'ithstanding water pressure of 300 pounds 



nch us; 



be 



Illy. 



The plies are to be started and pullr.: ^i. . )i i ■ 

 itrad i^ to be clamped in the jaus ..i .^l.,iu..i 

 The te^t shall be made on any ply of fabric in 

 le.Td weight frictic 



''"fdr'^^tr''°nK'h"of"die union between the breaker and tread and between 

 the breaker and cushion shall not he less than 28 pounds per inch, using 

 the standard dead weight friction te.' 

 fe) Strength of the union betwe 

 less than 16 pounds per inch, using 



. , . provided. 



hion-and carcass shall be not 



ndard dead weight friction test 



jfacturers bidding on government requirements 



he given consideration unless the maker submitting 

 hvit 'tating that he has maintained and will con- 

 t two cars used exclusively for test work, and 

 ,1 least 1.000 car miles per car per week. 



