[0001] The present invention is relative to a heel piece. It is known that ski bindings
present a toe piece and a heel piece, which are respectively designed to hold a ski
boot in a removable manner.
[0002] In detail, the ski boot has to be able to be removed from the ski binding:
- when the user wants to remove it;
- in case of impact or fall, i.e. when a given force threshold is exceeded, at least
as a function of the weight of the skier himself/herself. For this very reason, different
ski bindings are available on the market, in which both the toe piece and the heel
piece are provided with means for adjusting the release force for the release of the
ski boot.
[0003] Therefore, the object of the present invention is to describe a heel piece comprised
in a ski binding, which is not affected by the drawbacks described above and presents
a release concept that is different from the one of the heel pieces comprised in the
traditional bindings.
[0004] The present invention provides a heel piece comprised in a ski binding, as claimed
in the first claim.
[0005] The invention will now be described with reference to the accompanying drawings,
which illustrate a non-limiting embodiment, wherein:
- figures 1a, 1b illustrate a first embodiment of the heel piece comprised in a ski
binding, which is the subject-matter of the present invention;
- figure 2 illustrates a second embodiment of the heel piece;
- figure 3 illustrates a third embodiment of the heel piece, which is the subject-matter
of the present invention;
- figure 4 illustrates a fourth embodiment of the heel piece comprised in a ski binding,
which is the subject-matter of the present invention.
[0006] All the embodiments that will be described hereinafter share a common concept, that
is the one according to which heel pieces can bend to stress and, in this way, allow
the boot to be released, when a predetermined stress threshold is exceeded.
[0007] With reference to the figures mentioned above, number 1 indicates a ski binding as
a whole, comprising a toe piece 10 and a heel piece 2, which is the subject-matter
of the present invention. Figure 1 illustrates, in detail, a part of a first embodiment
of toe piece 2, which can be used in a ski activity such as ski mountaineering. In
particular, figure 1b shows how the heel piece is supposed to be installed on a ski.
[0008] Heel piece 2 is L-shaped and is provided with a first horizontal element 20a and
a second vertical element 20b, which are connected to each other; on the first horizontal
element 20a there are a lightening hole 21 and a plurality of fixing holes 22 for
fixing heel piece 2 to the ski; in the second vertical element 20b there are holes
that are suited to support the holding of the ski boot.
[0009] Said second vertical element 20b comprises a first left section 20s and a second
right section 20d, which are equal and symmetric to each other and are spaced apart
by a slit 29, which is parallel to a common direction of both sections 20s, 20d.
[0010] Furthermore, said second vertical element 20b presents a plurality of weakening holes
23 with lateral yielding, which are partially open towards the sides of the element
itself and, thus, are suited to allow the rear support to yield, once a predetermined
load has been exceeded.
[0011] Weakening holes 23 with lateral yielding cooperate with the flexibility of the second
vertical element 20b, so as to allow the release of the boot, when a resisting force
higher than a predetermined threshold is exceeded.
[0012] Besides the above-mentioned weakening holes, the second vertical element 20b of the
heel piece illustrated in figures 1A and 1B comprises, furthermore, fixing bolts 24
for fixing a heel lift element 25, which, if necessary, can be connected to the second
vertical element 20b by means of a pair of fastening rings or ties 26.
[0013] Heel riser 25, besides being useful to rise a heel or a rear part of the sole of
the ski mountaineering boot, also prevents the heel itself of the boot from being
trapped by the two protruding bars of the heel piece.
[0014] Furthermore, heel riser 25 allows the movement of left section 20s and of right section
20d of heel piece 2 comprised in the ski binding, which is the subject-matter of the
present invention, when it is arranged in a non-use position, i.e. during the downhill
ski run. This is allowed by a pair of openings, which, in use, fit within respective
rings of heel riser 25. Said openings deliberately present a clearance, which is suited
to allow the movement, i.e. the full release ability of the boot, on the side of left
section 20s and of right section 20d.
[0015] Furthermore, heel riser 25 presents a shape that allows the boot to enter the binding
developing a predetermined stress, so that it cannot be easily lifted while walking
and so that, likewise, the boot, in use, is not caused to engage the rings during
the walk.
[0016] In detail, heel riser element 25 comprises a protuberance 25a, which is designed
to allow the rising of the rear part of the ski boot.
[0017] As already mentioned above, vertical element 20b comprises, to be more precise, a
pair of bars, which are preferably parallel, each of which presents a respective weakening
hole 23 and a respective bolt 24 with fastening elements of the latter, if necessary;
in the case illustrated said fastening elements comprise a plurality of nuts.
[0018] Figure 2 illustrates a second embodiment of the heel piece comprised in a ski boot,
suited for example for the ski touring activity, which is different from the previous
embodiment due to the shape of the bars of the second element 20b.
[0019] The concept of programmed deformation can be applied not only to the bindings for
ski mountaineering, but also to the bindings for downhill skiing (Alpine skiing).
[0020] Figure 3 illustrates a further embodiment of heel piece 2, which is suited for Alpine
skiing.
[0021] Heel piece 2, which comprises a first horizontal element 20a, a second vertical element
20b, and a third release element 20c, and wherein the second vertical element 20b
is interposed between the first horizontal element 20a and the third release element
20c, presents all the three elements, which, despite being substantially connected
to each other in correspondence to their ends, are at least partially separated by
a fracture line 31, which causes them to be respectively divided into a left part
and a right part. Obviously, other fracture lines 31 can be present in other portions
of heel piece 2.
[0022] The first horizontal element 20a is the one in which fracture line 31 ends; fracture
line 31 can end in a through hole 20f, which is substantially arranged in correspondence
to the half of the first horizontal element 20a itself.
[0023] In particular, since the third embodiment of heel piece 2 shown in figure 3 has to
support and releasably constrain an Alpine ski boot, the second vertical element 20b
comprises a projecting edge 27, which, in use, faces the respective toe piece, so
as to allow the user to keep the boot locked towards the ski.
[0024] When a given threshold load is exceeded, fracture line 31 arranged on the second
vertical element 20b allows its parts, i.e. left section 20s and right section 20d,
to separate from one another and, thus, helps increase the stress exerted on the toe
piece, which will collapse more easily than the heel piece. Fracture line 31 allows
heel piece 2 to feature an important anti-shock effect, which, in ski bindings, is
normally performed by the system of the thrust spring. Possible holes or weakenings
allow the heel piece to open in case of frontal impact of the ski, for example in
case the tip of the ski itself gets stuck.
[0025] The profile of the second vertical element 20a, in this case, presents a curved shape,
which defines a circular or elliptic arc, so as to enable the exit of the boot.
[0026] Finally, figure 4 illustrates, in a prospective view, a fourth embodiment of heel
piece 2 for ski touring.
[0027] Heel piece 2 comprises a second vertical element 20b, which is shaped as a saddle
and is constrained by a pair of front and rear support elements 50a, 50b.
[0028] The front and rear support elements 50a, 50b present the shape of a parallelepiped
with smooth walls and comprise three parallel holes, which are arranged orthogonal
to the direction of maximum extension of the second vertical element 20b, and are
engaged by a screw 51 arranged in a central position, as well as two lateral pins,
which act as smooth guides; screw 51 allows an adjustment suited to vary the distance
between the second vertical element 20a and the front support element 50b; in use,
by acting on said screw 51, it is possible to adjust the distance that divides the
second vertical element 20b from the toe piece as a function of the length of the
ski boot and as a function of the thrust that has to be exerted on hell piece 2 itself
in order to releasably lock its movement. The screws and the pins present retainers
or split pins or also snap rings.
[0029] Screw 51 can house, on one of its ends opposite to its head, a spring that will remain
comprised between its respective retainer and rear support element 50b, in order to
absorb shocks.
[0030] Therefore, front 50a and rear 50b support elements substantially define a linear
movement area of the second vertical element 20b and determine, likewise, its limit
stops.
[0031] All the heel pieces described in the presents description can be made both of metal
material and of wood material; in particular, in case wood material is used, multi-layer
wood is particularly suited for the purpose. Alternatively, the heel pieces con be
made of composite materials, acetal resin or plastic materials according to the specific
needs.
[0032] Furthermore, it is important that the heel piece comprised in a ski binding according
to the present invention presents, in some versions, angles that are slightly smaller
than right angles. Indeed, in order to properly work, the heel pieces have to support
the natural thrust of the boot towards the toe piece, so as to guarantee the proper
compression of the boot.
[0033] Therefore, in order to normalize the compressions and the resistances, in case the
heel piece is made of certain plastic materials, it is advisable to provide certain
angles between the different elements 20a, 20b, so that the boot can be used in a
normalized situation, in terms of resistance, which is best suited for its release
in case of accident or fall or, in any case, after the predetermined release threshold
has been exceeded.
[0034] In particular, unlike ordinary heel pieces, the heel piece described in the description
does not allow the traditional adjustment of the stiffness or strength of the release
of the ski boot, as traditional heel pieces, but it is rather specifically designed
and calculated, in terms of release force, to fulfill the specific needs of the user,
thus allowing the development of a product that perfectly fits to the needs of the
user, i.e. a customized product.
[0035] Therefore, heel piece 2 comprised in a ski binding according to the present invention
can be applied, with good results, to skis used in ski mountaineering activities,
in which lightness and efficiency play an important role; the same also applies to
skis for extreme skiing or to race skis.
[0036] The same concept can also be used to produce telemark bindings, provided that there
is compatibility between the areas that have to be complementary between sole and
binding.
[0037] Therefore, the shape of the anchoring means illustrated fulfills a mere explanatory
function and is not limiting, since it represents a finite number of embodiments,
which are subject to a common concept of flexibility of the constraining element constraining
the boot to the heel piece itself.
[0038] The variations of the release resistance of the boot can be adjusted with subsequent
changes of the binding carried out by the manufacturer.
[0039] In case a client buys bindings of particular value and needs specific adjustments,
he/she can send the bindings back to the manufacturer who will take care of providing
the necessary holes or reinforcements.
[0040] Furthermore, the maximum resistance forces applicable prior to the release of the
boot can be separately adjusted for the toe piece and the heel piece.