вход по аккаунту


Патент USA US2404579

код для вставки
July 23, .1946.
_ w. s. COBEN
Filed Oct. 21, 1941
2 Sheets-Sheet 1
william ‘5. 60km _
July 23, 11946.
w_‘s_ (:QBEN
2,404,579 '
Filed Oct. 21', 194-1
2 Sheets-Sheet 2, '
101mm 5. Qo'ben
Patented July 23, 1946
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 Claim. (01. 152-409)
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
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
formed with a plurality
of traction
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.
Без категории
Размер файла
333 Кб
Пожаловаться на содержимое документа