Патент USA US2404579код для вставки
July 23, .1946. _ _ w. s. COBEN ‘2,404,579 TIRE CONSTRUCTION Filed Oct. 21, 1941 2 Sheets-Sheet 1 I3 INVENTOR william ‘5. 60km _ v ATTORNEYS v July 23, 11946. w_‘s_ (:QBEN ' 2,404,579 ' TIRE CONSTRUCTION Filed Oct. 21', 194-1 2 Sheets-Sheet 2, ' INVENTOR 101mm 5. Qo'ben ATTORNEYS ' Patented July 23, 1946 2,404,579 UNITED STATES PATENT OFFICE " 2,404,579 TIRE CONS TRUGTION William S. Cohen, Akron, Ohio, assignor to. The Firestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio Application October 21, 1941,‘ Serial No.‘ 415,851 1 1 Claim. (01. 152-409) '21 . . * This invention relates to tire constructions, and are somewhat narrower thanlsaid rib I5; 'Like more especially it relates to improved design of the latter, the lateral faces of the ribs l8 ‘are the tread portions of pneumatic tire casings. The serrated, the lugs that constitute the serrations invention has been found to be of. primary utility being designated L9, l9. The lugs IS on opposite in its application to large heavy duty tires, such 5 sides of each rib I8 are in staggered relation to as truck tires, which are subject to relatively heavy each other, and on that‘ side of each rib l8 that loads and severe service conditions. is nearest the rib IS, the lugs l9 are in staggered The chief objects of the invention are to im relation to the lugs [6 of the said rib l5. The prove the wearing qualities of pneumatic tires; arrangement is such that the grooves [3 between to improve the traction and anti-skid character 10 the rib l5 and ribs |8 has a zig-zag appearance. istics thereof; and to provide a tire tread that has The “lateral” traction elements are disposed a cooling eiTect on a tire at the hinge-points at the respective margins of the tread, which are thereof. Other objects will be manifest as the the shoulders or hinge points of the tire. Each description proceeds. of said lateral traction elements consists of a cir Of the accompanying drawings: 15 cumferential series of blocks 2|, 2| that are lon Fig. 1 is a perspective view of a pneumatic tire gitudinally spaced apart from each other, said casing embodying the invention; blocks being of greater length than width and Fig. 2 is a section, on a larger scale, on the line being disposed end to end. 2—2 of Fig. 1; The lateral face of each block 2| that con Fig. 3 is a section, on a larger scale, on the line 20 fronts an intermediate rib I8 is serrated, the 3-3 of Fig. 1; Fig. 4 is a section on the line 4—4 of Fig. 2; Fig. 5 is a section on the line 5--5 of Fig. 2; and Fig. 6 is a fragmentary developed plan view, on a larger scale, of the tread portion of the tire 25 shown in Fig. 1. rib l8 so that the intervening groove I3 is of zig zag appearance. vThe opposite face of each block 2| is sloped from the circumferentially arranged Referring to the drawings, there is shown a tire comprising the usual carcass l0 of a plu rality of fabric plies, dual bead cores H, H at each margin of said carcass, as is conventional 30 margin of the block to the sidewall of the tire. A characteristic feature of the “lateral” traction elements is their transverse width, which width is less than the width of the “intermediate” ele ments IS on the ground-engaging surface of the elements. It will also be observed that the blocks Said tread structure is formed with a plurality _ relation to the blocks 2| on the opposite side of of circumferentially extending driving or trac tion elements which for convenience may be designated as “central,” “intermediate,” and “lat the tread. Adjacent blocks 2| of each series are connected to each other by ribs 23 that are in practice in heavy duty tire construction, and a tread structure, designated as a whole by the numeral l2, on the periphery of the said carcass. 2| on one side of the tread are staggered with tegral therewith, said ribs being of narrower width than the blocks, and being somewhat lower circumferentially extending grooves I3, I3. " in height, as is best shown in Fig. 3. The “central” traction element is a rib l5 that is 40 The grooves l3 that separate the traction ele symmetrically disposed along the centerline of the ments are not of uniform depth throughout the tread, equidistant from the lateral margins 01‘ circumference of the tire, but have local regions shoulders thereof. The respective lateral faces of shallower depth, which regions are spaced of the rib | 5 are serrated, that is, they are formed apart from each other a distance equal to the with a succession of lugs IS, IS that are wedge 45 spacing of three of the lugs l6 or I9. The re shape in plan, and which project into the grooves gions of shallower depth are produced by upward |3 at opposite sides of the rib. The lugs I6 on swells or bulges 25 in the bottom of the grooves, one side of the rib are disposed in staggered rela— which swells or bulges are located at the apexes tion to the lugs on the other side of the rib, as is of lugs that constitute the serrations of the trac- ‘ most clearly shown in Fig. 6. 50 tion elements. The function of said bulges 25 is The “intermediate” traction elements are cir to impede the progress of ?ex cracks that may cumferential ribs l8, l8 that are disposed adja originate in the bottom of the grooves l3. cent the rib |5 on opposite sides thereof. The The invention provides a’tire having a greater ribs | 8 as shown are identical with the rib l5 proportion of its rubber at the center of its tread except in one important feature, namely, they 56 where service conditions are most severe, with the eral” elements, said elements being separated b ' wedge-shaped lugs that constitute the serrations being designated‘22. The lugs 22 are disposed in staggered relation to the lugs I9 of the adjacent ’ 2,404,579 3 result that the wearing quality of the tire is im proved. Furthermore, the provision‘ of narrower traction elements toward the sides of the tread increases the ?exibility thereof and improves its ' traction and non-skid characteristics. The fea ture of providing lateral traction elements in the form of blocks‘contributes to the ?exibility and traction characteristics of the tread, and also exerts a cooling effect onvthe tire at the hinge points thereof where ?exure produces the greatest heat. lateral margins of the tread, one of said ribs being ‘wider than the others and being disposed along the center line of the tread, all of said ribs having their lateral faces uniformly and continuously serrated throughout, said blocks being of greater length than width and having one lateral face confronting an outer rib of said tread, said con fronting ' face of said blocks‘ being serrated throughout their length and their other lateral faces being smooth, said blocks being connected to each other by means of a relatively narrow rib Modi?cation may be resorted to without .del- T '7 whose height is less than the height ‘of the blocks, said traction elements de?ning circumferential parting from the spirit of the invention, or the scoperthereof as de?ned by the' appended claim. Q (grooves therebetween and the bottom of said grooves having a plurality of upwardly extending ‘ What is claimed is: bulges at intervals, said intervals being equal to Apneumatic tire comprising a tread portion‘ the spacing of three of the said serrations whereby tractionelements formed with a plurality comprising of traction endless element's, circumfer» said, , progressive development of a crack in the groove _ of the tire is prevented,V ' entially extending ribs in the central area of the tread and a. circumferential series of longitu 20.v dinally spaced blocks disposed at the opposite ‘ WILLIAM ‘s. coBEN.