Note: Descriptions are shown in the official language in which they were submitted.
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PERSONAL TRACTION DEVICE
FIELD OF THE INVENTION
[0001] This invention pertains to personal traction devices that can be worn
over
footwear such as shoes or boots so that traction mechanisms extend over the
sole of the
shoe for increasing the traction of the sole.
BACKGROUND OF THE INVENTION
[0002] There are many versions of personal traction devices that can be
mounted to
shoes, boots, or the like, for increasing traction when walking on ice or snow-
covered
surfaces.
[0003] Such devices often include stretchable mounting straps that are
configured to
grasp the toe and heel portions of the boot. The traction mechanisms are
connected to the
straps and may be in the form of chains, flexible material with embedded metal
studs, or
other material with roughened or irregular surfaces that extend across the
sole of the boot,
usually in the vicinity of the sole that underlies the heel and metatarsal
portion of the foot.
[0004] A number of factors must be considered when designing such traction
devices.
For example, some mechanisms that provide very good traction, such as
outwardly
projecting metal spikes, may suffer from rapid wear or be uncomfortable to
walk on for a
length of time, especially when one is in an environment where the walking
surface may
change between dry, hard surfaces and icy or snow-packed surfaces. Also, it is
difficult
to durably mount metallic members, such as spikes or studs, to a flexible
cross strap or
the like. To this end, some designs provide for replacing dislodged or worn
spikes, which
necessarily increases the cost and complexity of the device.
[0005] Some mechanisms that extend across the sole of the shoe or boot, such
as
relatively low-profile chains or coiled spring-like members may be more
comfortable to
the user, but they typically have less aggressive traction characteristics.
[0006] The present invention is directed to a personal traction device that
provides a
traction mechanism that is very comfortable underfoot, while providing
excellent traction
over slippery surfaces as well as excellent long-term wear.
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BRIEF SUMMARY OF THE INVENTION
[0006a] Accordingly, there is provided a traction device, comprising: an
elastomeric
member; a cable assembly connected to the elastomeric member and having an
elongated
segment; a cleat carried on the segment; the cleat having: an elongated core
through which
extends a passage having a central axis, and through which passage fits the
segment so that
the cleat is rotatably carried thereon; a protrusion extending radially from
the core and
including a first inclined surface thereon that is oblique to the central axis
of the passage to
thereby shape the protrusion such that the protrusion tapers to a first bladed
edge.
[0006b] There is also provided a traction device, comprising: an elastomeric
member;
a cable assembly connected to the elastomeric member and having an elongated
segment;
a cleat carried on the segment; the cleat having: an elongated core through
which extends
between opposing end faces of the core a passage having a central axis, and
through which
passage fits the segment so that the cleat is rotatably carried thereon; a
protrusion extending
radially from the core and including two inclined surfaces thereon that are
oblique to the
central axis of the passage and join to define the protrusion as a wedge
having an outermost
edge.
[0006c] In a further aspect, there is provided a cleat for use with a traction
device,
comprising: an elongated core through which extends a passage having a central
axis;
a protrusion extending radially from the core and including a first inclined
surface thereon
that is oblique to the central axis of the passage to thereby shape the
protrusion such that the
protrusion tapers to a first bladed edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Fig. 1 is a perspective view of a personal traction device in accord
with the
present invention shown mounted to a boot.
[0008] Fig. 2 is a plan view of a forward or toe assembly component of the
personal
traction device.
[0009] Fig. 3 is a plan view of a rear or heel assembly component of the
personal traction
device.
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[0010] Fig. 4 is a perspective, enlarged view of one embodiment of a cleat
component of
the personal traction device.
[0011] Fig. 5 is an end view of the cleat of Fig. 4.
[0012] Fig. 6 shows a side view of a portion of a traction device.
[0013] Fig. 7 is a perspective, enlarged view of another embodiment of a cleat
component of the personal traction device.
[0014] Fig. 8 is an end view of the cleat of Fig. 7.
[0015] Fig. 9 is a side view taken along lines 9 - 9 of Fig. 10.
[0016] Fig. 10 is a side view taken along lines 10 - 10 of Fig. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] Fig 1 illustrates the traction device 20 mounted to a boot 22. A
generally ring-
shaped elastomeric member 24 is stretched around the boot, above the sole of
the boot. The
elastic properties of that member 24, as well as the friction between the
member and the boot,
secure that member in place.
[0018] The elastomeric member 24 is formed with several downwardly projecting
tabs
26. Each tab 26 is formed with an aperture for receiving a connector link 28
of a cable
assembly 30, 32 that extends across the sole (underside) of the shoe as
described more fully
below.
[0019] Fig. 2 is a plan view of the forward or toe cable assembly 30 of the
personal
traction device. This assembly comprises a single length of stainless wire
rope 34, shown in
dashed lines, and preferably having a 0.0625-inch (1.6 mm) diameter. The ends
of the rope
34 are overlapped and fastened by a crimp 36.
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[0020] Crimps 38 are also applied in two places near the forward part of the
rope to
define two spaced-apart, forward connector loops 40 in the rope. Each of these
loops is
captured by one of the above mentioned connector links 28 that extend from
each tab 26
of the elastomeric member 24.
[0021] Similarly, crimps 42 are applied in two places near the rearward part
of the rope
to define two spaced-apart, reward connector loops 44 in the rope. Each of
these loops is
also captured by a connector link 28 that extends from a tab 26 of the
elastomeric member
24.
[0022] With continued reference to Fig. 2, the overall wire rope 34 can be
considered
as having four segments, each segment extending between a connector loop. For
example, a transverse segment 46 of the assembly extends between the forward
connector
loops 40. Another transverse segment 46 extends between the rearward connector
loops
42. A lengthwise segment 48 extends between a forward connector loop 40 and
rearward
loop 44 on each side of the assembly.
[0023] As seen in Fig. 2, the segments are arranged in a generally trapezoidal
shape,
with the two lengthwise segments extending along, but not parallel to, the
long centerline
50 of the assembly (that centerline corresponding to the centerline of the
boot to which
the assembly is attached). The two transverse segments 46 extend generally
across and
perpendicular to that centerline 50.
[0024] Each segment of the wire rope 34 is strung or threaded with cleats 52
and
spacers 70 such that a spacer 70 is located between each cleat 52. Figs. 4 and
5
respectively illustrate in enlarged perspective and end views the details of
on embodiment
of a cleat 52 made in accordance with the present invention.
[0025] In particular, each cleat 52 depicted in the embodiment of Figs. 4 and
5 is
formed of durable metal, such as stainless steel, and is generally cross-
shaped. The cleat
includes a round through-passage 54 having a diameter (eg, 0.0781 inches or
2.0 mm)
that is slightly larger than that of the wire rope that slides through the
passage.
Accordingly, the threaded cleat is free to rotate about the rope 34.
[0026] The cross-shaped cleat 52 defines several edges where two surfaces
meet. For
example, as shown in Figs. 4 and 5, a first edge 56 of the cleat is defined by
the junction
of the two surfaces shown at 58 and 60. Another such edge 56' is defined by
the junction
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of the two other surfaces shown at 58' and 60.' It is noteworthy that this
pair of first
edges 56, 56' are parallel to one another and reside in a common plane, which
is indicated
by the "ground" line 62 in Fig. 5.
[0027] The cleat 52 is symmetrical about its center. Accordingly, a pair of
second
edges 64, 64' matching but opposite to the first pair 56, 56' are defined on
the opposing
side of the cleat. Those edges 64, 64' are respectively defined by the
junctions of
surfaces 74, 76 and 74', 76' and likewise disposed in a common plane, which is
shown by
the "sole" line 66 in Fig. 5. Plane 66 is parallel to the opposing plane 62.
[0028] The configuration of the first set of edges 56, 56' as shown in Fig. 5,
orients
those edges to be pointing downwardly in the direction as shown by arrows "D"
in Fig. 5.
In this regard, a line that bifurcates the angle between the two surfaces that
form the edge
56, 56' is aligned with the direction that the edge is "pointing." Thus, in
Fig. 5 the edges
56, 56' are pointing in the downwardly direction "D," normal to the plane 62.
[0029] On the opposite side of the cleat 52, the second set of edges 64, 64'
as shown in
Fig. 5 are oriented so that those edges are pointing upwardly as indicated by
arrows "U"
in Fig. 5, perpendicular to the plane 66 in which the edges are disposed.
[0030] Considering further the cleat shown in Fig. 5, the lower or ground
plane 62 may
be considered the surface (such as an ice-covered walkway) upon which the
cleat 52 bears
when fastened to the sole of a boot as shown in Fig. 1. The opposing plane 66,
in this
instance, corresponds to the underside or sole of the boot 22.
[0031] Consequently, all of the cleats of the device, when pressed between the
sole 66
and ground surface 62 by the weight of the wearer, will have a downwardly
pointing pair
of sharp edges forced into the icy surface for providing excellent traction.
In this regard,
the configuration of the cleat (as described above) is such that when pressed
between two
planes (Fig. 5) it will assume a stable equilibrium position. Specifically,
the cleat rotates
about the rope 24 by an amount sufficient to direct a pair of edges to rest
upon or point to
the lower surface, and an opposing pair of edges points to or engages the
surface of the
upper plane.
[0032] In one embodiment, the outermost radial surfaces of the cleat, such as
surface
60' is formed to be slightly arched or convexly curved, which curvature may
enhance the
tendency of the cleat to arrive at its stable equilibrium orientation just
discussed. It is
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contemplated, however, that such surfaces could also be flat, and the cleat
would still
move to its stable equilibrium orientation (Fig. 5) when pressed between two
generally
parallel planes.
[0033] As noted, the cleat is symmetrical so that the cleat shown in Fig. 5
will assume
a stable equilibrium orientation at any one of four different positions. That
is, the cleat
will assume a stable equilibrium orientation when rotated by any integer
multiple of 90
degrees beyond what is shown in Fig. 5. Put another way, a third pair of edges
80, 80'
and opposing fourth pair of edges 82, 82' are formed in the cleat 52 to
function in the
same manner as the above-discussed first and second edge pairs in instances
where the
cleat happens to be rotated 90 degrees from the orientation shown in Fig. 5.
[0034] It is noteworthy that the effect of the upwardly pointing edges of the
cleat
(edges 64 and 64' in Fig. 5), in addition to helping to stabilize the cleat in
the position
where the opposing edges point directly into the slippery surface 62, is to
provide cutting
edges pointed toward the underside of the shoe. These edges tend to shear
through ice,
snow and other debris that may on occasion move between the cleat and the
sole. In this
regard, the upwardly pointing cleat edges provide a self-cleaning action for
preventing
unwanted buildup of material on the device.
[0035] Although the cleat shown in the figures has inner corners defining a 90-
degree
angle, it is contemplated that those corners could also be formed as concave
curves, as
shown by the dashed lines 88 in Fig. 5.
[0036] The opposing end faces 90 of the cleat are flat and reside in planes
perpendicular to the long axis of the passage 54 in the cleat. It will be
appreciated that
where the end surfaces 90 join the edges (such as edges 56' or 64' shown in
Fig. 4) there
is defined a relatively sharp point 92 in the cleat. Consequently, each end of
the cleat has
associated with it eight sharp points 92. The wire rope upon which the cleats
are carried
is free to bend slightly to accommodate irregular surfaces, walking motions,
etc.
Consequently, the numerous sharp points 92 of the cleat will dig into the icy
surface for
enhancing traction, preventing sliding and otherwise supplement the traction
provided by
the edges discussed above.
[00371 The spacers 70 mentioned above (See Figs. 1, 2, and 6) are hollow,
cylindrical
members, preferably made of stainless steel. As shown in Fig. 6, the outer
diameter of
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the spacers is significantly less that the maximum cross sectional width of
the cleats 52.
As a result, the numerous sharp points 92 of the cleats are exposed (for
supplementing
traction) by a degree much greater than would be the case if the cleats were
threaded
adjacent to one another with no such spacers.
[0038] Fig. 3 shows in plan view the rearward or heel cable assembly 32 of the
personal traction device. This assembly comprises a single length of stainless
wire rope
94, having a 0.0625-inch (1.6 mm) diameter and shown in dashed lines. The ends
of the
rope 94 are fastened by a crimp 96. This assembly includes alternating cleats
52 and
spacers 70 configured and arranged as described above in connection with the
toe cable
assembly 30.
[0039] Apex loops 98 are threaded onto the wire rope at each of three corners
of the
triangular-shaped heel assembly. Alternatively, crimps could be used instead
of or in
addition to these loops to define and stabilize the shape of the assembly.
Each of the apex
loops 98 is captured by a corresponding connector link 28 that extends from
each tab 26
of the elastomeric member 24.
[0040] With continued reference to Fig. 3, the overall wire rope 94 can be
considered
as having three segments, each segment extending between an apex loop 98. For
example, a transverse segment 100 of the assembly extends between the two
forward
apex loops.
[0041] Figs. 7 - 10 illustrate another embodiment of a cleat component of the
present
invention. This cleat 152 is formed of durable material comprising, for
example, stainless
steel. The cleat 152 is generally cross-shaped and can be considered as having
a central
core portion 153. The core 153 of the cleat has flat, opposing end faces 160
and has
formed through it a round through-passage 154 having a diameter (e.g., 2.0 mm)
that is
slightly larger than that of the wire rope that slides through the passage.
[0042] The passage 154 (like the earlier described passage 54) includes a
central axis
as shown in the figures as line 155 for reference purposes.
[0043] Four spaced apart protrusions 157, 159, 161, 163 extend radially
outwardly
from the core 153 of the cleat 152. These protrusions are evenly spaced apart
from one
another and are generally plate-like members, preferably having thicknesses
(Fig. 8)
slightly greater than the diameter of the passage 154.
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[00441 In this embodiment, some of the protrusions are shaped to have sharp,
bladed
edges 165. Bladed edges are, for the purposes of this description, edges
formed from
surfaces that meet at an angle of less than 90 degrees. In the present
embodiment, the
bladed edges are provided on two diametrically opposed protrusions 161, 163
(See Figs. 7
and 10).
[00451 Each bladed edge 165 is made up of the junction of two surfaces, one of
which
is a surface 167 that is formed so that it is inclined to be oblique (that is,
neither parallel
nor perpendicular) to the central axis 155 of the cleat. In this embodiment,
that inclined
surface 167 joins the extension of the end surface 160 of the cleat core (Fig.
10), thereby
defining a tapered portion in the protrusion 161, 163 that terminates in the
bladed edge
165. In a preferred embodiment, each protrusion 161, 163 has two inclined
surfaces 167
and associated tapered portions, thus defining a bladed edge 165 on each of
the opposite
ends of the protrusion.
[00461 It is contemplated that a single inclined surface may be formed to
extend along
the length of the cleat and thus define a single bladed edge on one end of the
cleat.
Moreover, it is also contemplated that the cleat could be made with the end
surface 160 of
the cleat oriented to be inclined oblique to the central axis and thus serving
as the inclined
surface that imparts a taper into the protrusion and form a bladed edge. (For
instance, in
Fig. 4, the end face 90 of that cleat 52 may be formed obliquely to the
central axis of the
passage 54 and thereby defining at edge 60 a bladed edge as discussed in the
present
embodiment.)
[00471 It is noteworthy here that the bladed edges 165 described above are
particularly
useful for digging into ice-covered surfaces to improve traction. Moreover,
all of the four
protrusions may be formed with one or more such bladed edges. In the preferred
embodiment, however, the other opposing pair of protrusions 157, 159 (See
Figs. 7 and 9)
are each shaped to define a wedge 169. For the purposes of this description, a
wedge is
considered to be the shape resulting from the junction of two surfaces with an
angle of 90
degrees or more between them. In the present embodiment (see, in particular,
Fig. 9), the
wedge 169 is formed by two inclined surfaces that extend from opposing ends of
the
protrusion to join midway between those ends and define a sharp, outermost
edge 171 of
the wedge.
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[0048] In view of the foregoing description of the embodiment of Figs. 7 - 10
it can
be seen that the protrusions 157, 159, 161, 163 are arranged around the
central axis 155
(Fig. 7) in a manner such that each protrusions 161, 163 shaped to have
opposing bladed
edges 165 is adjacent to a protrusion 157, 159 that is shaped as a wedge with
a central
outermost edge 171. One advantage to arranging the protrusions in this
alternating
manner is to maintain sufficient material in the cross section of the cleat
(that is, along the
axis 155) to increase durability of the cleat over what it might be if blade
edges were
formed on all four protrusions.
[0049] Moreover, in instances where, as in this embodiment, the protrusions
are sized
to extend radially outwardly by the same distance (see Fig. 8), the adjacent
blade edges
165 and wedge edge 171 provide three tripodal points (shown at 175 in Fig. 7)
that are
disposed in a common plane and thus support the cleat 152 in a stable position
upon a flat
surface.
[0050] It will be appreciated that a similar tripodal arrangement of points
175 is
provided on four sides of the cleat 152 (that is, at 90 degree intervals). As
a result, the
cleat 152, when pressed between a shoe sole and ground surface by the weight
of the
wearer (those surfaces shown, for example at 62 and 66 in Fig. 5), will
provide a
downwardly facing tripod of sharp points 175 forced into the icy surface for
providing
excellent traction, as well as an upwardly projecting tripod of sharp points
175 to engage
the sole of the shoe.
[0051] The embodiments illustrated and described are not intended to be
exhaustive or
limit the invention to the precise form disclosed. The embodiments were chosen
and
described in order to explain the principles of the invention and its
application and
practical use, and thereby enable others skilled in the art to utilize the
invention.
Modifications, therefore, may be made to the preferred embodiments while still
falling
within the scope of the claims.
[0052] For example, each cable assembly could be modified to have more or
fewer
segments, or arranged in patterns other than the trapezoidal or triangular
ones depicted
here. Also, the tabs depending from the mounting strap may be equipped with
rivets that
capture one or more links for attachment to the loops on the wire rope. Such
links may be
bent or otherwise arranged so that the tab-to-wire rope connection rides
smoothly over the
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boot. Moreover, it is also contemplated that many of the benefits of the
configuration of
the cleat 152 described above could be obtained if only three evenly spaced
protrusions
(rather than four) were employed.
