Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
A-4219
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James W. Coutts
IMPROVEMENTS RELATING TO CABLE-TYPE TIRE CHAINS
SPECIFICATION
Back~round of the Invention
The invention relates to cable-type chains for
use on vehicle tires, for improving traction, for
example, in ice or snow conditions. In particular,
the invention is concerned with cable-type chains
which include a pair of elongate flexible side mem-
bers adapted to extend circumferentially around oppo-
site side walls of a tire, and cross members provided
with traction means such as traction sleeves, the
cross members being connected between the side members
so as to extend over and across the tire tread.
Chains of this general type are well known; see, for
example, U.S. Patent No. 4,155,389.
It is desirable in the design of cable-type
tire chains, to maximize traction, vehicle stability
and chain life, consistent with minimizing wear both
of the tire and of the chain itself. The present
invention is directed, inter alia, toward aspects of
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cable-type tire chain design adapted to provide the
tire chain with favorable characteristics in the above
or other respects.
Summary of the Invention
In one of its aspects, the invention provides a
novel type of traction sleeve for use on a cable-
type tire chain, the sleeve comprising a body portion
in the form of a right cylinder, and at least one end
portion flared outwardly from the body portion, the
end portion defining a notch providing sharp corners
on one end of the sleeve. Preferably, both end
portions of the sleeve are flared and notched as
indicated, and conveniently, the sleeve may be formed
by bending an initially flat metal strip into tubular
form in a suitable die or the like.
In another of its aspects, the invention provides
a cross member for a cable-type tire chain, the cross
member being provided with traction means, preferably
traction sleeves, and having at its opposite ends
attachment means for connecting the cross member to
side members of the chain, wherein the cross member
comprises a cable covered over at least a part of its
length with a sheath of wire wound helically around
the cable, and with the sheath being free to rotate
on the cable. Preferably the cross member construc-
tion is such as to provide elongate sheaths at least
at opposite end portions of the cross member, with
traction sleeves freely rotatably mounted on the end
portions over the wire sheaths.
In still another of its aspects, the invention
provides a cross member for a cable-type tire chain,
the cross member being provided with traction means
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and having at its opposite ends attachment means for
connecting the cross member to side members of the
chain, the attachment means including, in each case,
a connector element fixed to the end of the cross
member, the connector element having a head with a
curved outer surface (conveniently, the head may be
part-spherical), the head being adapted to be rotatably
received in a complementary connector element attached
to one of the side cables, in a manner permitting
rotation of the cross member about its longitudinal
axis.
Additional features and advantages of the
invention will be apparent from the ensuing descrip-
tion and claims taken in conjunction with the accom-
panying drawings.
Brief Description of the ~rawings
Figure 1 is a perspective view of a vehicle tire
equipped with a tire chain constructed in accordance
with the invention;
Figure 2 is an enlarged sectional view on line
2-2 of Figure l;
Figure 3 is an exploded perspective view of
parts of the tire chain shown in Figure 1, including
a cross member and a connector element;
Figure 4 is a side elevational view of a traction
sleeve;
Figure 5 is an enlarged sectional view on line
5-5 of Figure 3; and
Figure 6 is an enlarged sectional view on line
6-6 of Figure 3.
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Description of Preferred Embodiment
As shown in Figures 1 and 2, a vehicle tire 10
is provided with a cable-type tire chain comprising
elongate flexible side members 12 and 14 (only one
side member 12 is visible in Figure 1), which extend
circumferentially around opposite side walls 16 of
the tire, and cross members 18, carrying traction
means in the form of traction sleeves 20, the cross
members being connected between the side members
and extending over and across the tire tread 22. The
opposite ends of the respective side members 12 and
14 may be connected together, in known manner, by
any suitable connector 24 (Figure 1), so that the
cable chain securely embraces the tire. Side members
12 and 14 may, for example, comprise stranded metal
cable or other suitable elongate flexible material.
Fach of the cross members 18, see particularly
Figures 2 and 3, comprises a length of cable 26 (such
as stranded-metal aircraft cable) divided, by
bushings 28 crimped to the cable, into a central
section A and outer sections B and C. A wire is
helically wound around central section A so as to pro-
vide an elongate sheath 30 extending substantially
the entire length of the central section. The
diameter of the sheath is such that it can rotate
freely on the cable 26. Outer sections B and C are
likewise provided with freely rotatably helically
wound elongate wire sheaths 32 and 31. Each end of
the cross member has a connector element in the form
of a further crimped-on bushing 36 with a part-
spherical head 37. Each of the cable sections B and
C carries a number of the traction sleeves 20, over
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the respective sheaths 32 and 34, the diameter of
the sleeves 20 and the number of sleeves being such
that they are freely rotatable.
The traction sleeves (see Figure 4) each have a
body portion 35 in the form of a right cylinder and
outwardly flared end portions 38. The end portions
define V-shaped notches 40 providing sharp corners
42 at the opposite ends of the sleeve for biting into
ice, snow or the like. Bushings 28 have part-
spherical heads 29, which may be received in theflared ends of the innermost sleeves and provide
bearing surfaces which facilitate sleeve rotation.
Conveniently, the sleeves may each be formed by bend-
ing ~in a suitable die or the like) an initially
flat strip of metal into tubular form with flared
end portions and so that opposite edges 39, 41 of
the strip are juxtaposed in the body portion of the
sleeve in parallel to the sleeve axis. With this
procedure, the flaring of the end portions in itself
may form the V-shaped notches 40, which are defined
between the end sections of ed~es 39 and 41.
It will be noted that the lengths of sections
~, B and C of the cross members are such that when the
tire chain is fitted to a tire, the traction sleeves
are located in the vicinity of the tread shoulders
22a, and 22b, with the center of the tire tread being
free of sleeves. This is preferred, but not essen-
tial, and, the sleeves could be continued across the
entire tread. (In this case, bushings 28 could be
omitted and a single wire sheath could be used for
the entire length of each cross member.) Further,
while in the illustrated embodiment, there are unequal
numbers of traction sleeves on the respective end
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portions of the cross member, the actual number of
sleeves used in practice may be varied to suit dif-
ferent applications.
The ends of the cross members 18 are connected
to the side members 12 and 14 by attachment means
including the bushings 36 and complementary connector
elements 34 shown particularly in Figures 2 and 3.
Each connector element 34 is formed from a flat
metal plate having one end 46 bent to form a tab
by which the element 34 is crimped firmly to the
relevant side member. The other end of the element
34 is bent to form a further tab 48 having a keyhole-
like opening 50, adapted to receive, through its
large end, the head 37 of one of the end bushings 36
of the cross member when tab 48 is lifted away from
the body of the element. The bushing 36 can then be
moved down opening 50 toward the end of element 34.
When tab 48 is then flattened toward the body of
the plate, head 37 becomes trapped in element 34 as
shown in Figure 2, the narrow part of opening S0
being of insufficient width to permit withdrawal of
head 37, and the flattening of tab 48 preventing
head 37 from moving toward the large end of opening
50. The connector configuration, however, due inter
alia to the part-spherical head 37, permits rotation
of the cross member about its longitudinal axis.
The cross member can be released by bending tab 48
to the position of Figure 3 (with the aid of a tool)
and removing head 37 through the large end of open-
ing 50.
The ability of the cross member cables 26 torotate relative to the connector elements 34, along
with the free rotational mounting of the wire sheaths
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30-32 and of the traction sleeves, contributes
significantly to reducing or at least equalizing wear
on the cable chain. Additionally, the specific de-
sign of the traction sleeves imparts good lateral
traction to a tire, while resisting clogging by
ice chips or the like. Further, the connector ele-
ments provide a rather low-profile connection between
the cross members and the side members which is useful
in vehicle wheel wells having limited clearance,
and the connections may also permit a degree of
lateral hinging as between the side members and the
ends of the cross members useful in accommodating
changes in tire profile.
While only a single preferred embodiment of
the invention has been described herein in detail,
the invention is not limited thereby and modifica-
tions can be made within the scope of the attached
c laims .
This application is a division of Canadian patent
application serial number 397,824, filed March 8, 1982.
