U.S. patent application number 12/224101 was filed with the patent office on 2009-05-28 for footwear heel.
Invention is credited to Stefano Frasconi.
Application Number | 20090133291 12/224101 |
Document ID | / |
Family ID | 36950206 |
Filed Date | 2009-05-28 |
United States Patent
Application |
20090133291 |
Kind Code |
A1 |
Frasconi; Stefano |
May 28, 2009 |
Footwear Heel
Abstract
A heel for footwears including a body (1) and an elongated
support portion (1a) wherein a rigid reinforcing core (2) is
embedded and has a stem-like structure with a substantially
frusto-conical cross section.
Inventors: |
Frasconi; Stefano; (Campi
Bisenzio (Firenze), IT) |
Correspondence
Address: |
POLLACK, P.C.
THE CHRYSLER BUILDING, 132 EAST 43RD STREET, SUITE 760
NEW YORK
NY
10017
US
|
Family ID: |
36950206 |
Appl. No.: |
12/224101 |
Filed: |
June 6, 2006 |
PCT Filed: |
June 6, 2006 |
PCT NO: |
PCT/IT2006/000419 |
371 Date: |
August 17, 2008 |
Current U.S.
Class: |
36/108 ;
36/34R |
Current CPC
Class: |
A43B 21/24 20130101;
A43B 21/36 20130101 |
Class at
Publication: |
36/108 ;
36/34.R |
International
Class: |
A43B 23/00 20060101
A43B023/00; A43B 21/00 20060101 A43B021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2006 |
IT |
FI2006U000009 |
Claims
1. A heel for footwear comprising a body and an elongated support
portion wherein a rigid reinforcing core is embedded, the
reinforcing core having a stem-like structure with a substantially
frusto-conical cross section.
2. The heel set forth in claim 1, wherein the reinforcing core is
made of ERGAL 7075.
3. The heel set forth in claim 1, wherein the reinforcing core
comprises a stem with a lower end and an upper end, the lower end
being formed with a bore, in which a shank of a heel tip is
forcibly engaged, the upper end being formed with an enlarged head
to secure the reinforcing core into the heel body.
4. The heel set forth in claim 1, wherein the stem has a conicity
increasing without interruption from the lower end.
5. The heel set forth in claim 1, wherein the profile of the stem
is in the shape of an arc of circumference radiusing the lower end
to the upper end.
6. The heel set forth in claim 5, wherein the arc is substantially
tangential to the perpendicular of the lower end of the stem
intersecting the stem lower end at the edge thereof.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of
footwear, in particular woman's footwear, and more in particular
relates to a heel for footwear, especially a so called stiletto
heel.
BACKGROUND OF THE INVENTION
[0002] As known in the field of footwear, a stiletto heel is a type
of high heel, essentially for woman's footwear, featured by a high
height/section ratio. Though all high heels require suitable means
for their reinforcement, this is absolutely indispensable in the
case of stiletto heels, in view of their slenderness, which makes
them insufficiently resistant to shear stress and bending. Normally
in order to increase the mechanical strength of high heels in
general and of stiletto heel in particular, it is customary to
reinforce them by a core made of rigid, generally metallic
material. Examples of these reinforcing cores are illustrated for
instance in the British patents n. GB 2012557 and 2063645. In these
cases the reinforcing core is made up of a steel tubular member
having a longitudinal slit, as the core is obtained by bending of a
rectangular stripe. The tubular reinforcement member is embedded in
the heel when it is injection moulded and then is finished with a
heel tip having a shank forcibly engaged within the tubular
member.
[0003] In the specific case of high heels the needs for lightness
and resistance, which have to be both satisfied, are seriously
hindered by the fact that the reinforcing core section has to be
particularly small. This definitely implies that no one of the high
heels which are now available on the market meet the resistance
provision set forth in ISO standards EN-ISO.19956/04, unless either
increasing the reinforcing core section but losing high heel's
slenderness, or using high resistance materials, such as steel, but
in this way negatively affecting heel lightness.
SUMMARY OF THE INVENTION
[0004] The object of the present invention is to provide a heel for
footwear, in particular a stiletto heel, which has high lightness
and, at the same time, mechanical resistance to shear and bending
stress.
[0005] Another object of the present invention is to provide a heel
of above mentioned type which meets the requirements of EN-ISO
19956/04 in the matter of fatigue strength.
[0006] These objects are achieved with the heel for footwear
according to the invention, which includes a body and an elongated
support portion wherein a rigid reinforcing core is embedded.
According to the invention, the core has a stem-like structure with
a substantially frustoconical cross section. Furthermore the
reinforcing core is preferably made of ERGAL 7075.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention will now be illustrated more in detail by the
following description of an exemplifying, non-limiting embodiment
thereof, with reference to the attached drawings, in which:
[0008] FIG. 1 is a partially exploded sectional view of a heel for
footwear in accordance with the invention;
[0009] FIG. 2 shows a perspective view of the reinforcing core of
the heel shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Referring to the aforesaid figures, it has been indicated at
1 a body of a stiletto heel obtained by injection molding in a
conventional way, and at 2 a reinforcing core included in its
elongated support portion 1a during the injection moulding
manufacturing process.
[0011] The reinforcing core 2 comprises a stem 3, with a
substantially frustoconical section, ending with an head 4 of
larger cross-section. The stem 3 has a length and a section
suitable for allowing it to be embedded into a stiletto heel of
conventional size.
[0012] The core 2 develops from a lower end 3a of the stem 3 with a
first stem portion 5a that has a very low conicity and is radiused
to a second stem portion 5b of greater conicity. The head 4 extends
from the upper end 3b of the stem 3.
[0013] It is very important that the stem portions 5a and 5b with
different conicity would be joined without discontinuity so as to
avoid any presence of critical sections, on which outward stresses
can concentrate, along the stem 3 of the core 2. To this end the
reinforcing core conicity preferably increases from its lower end
3a, which is the one with the lowest section.
[0014] In a preferred embodiment of the invention the profile of
the stem 3 is in the shape of an arc of circumference radiusing the
lower end 3a to the upper end 3b of the stem 3. In particular said
arc of circumference is substantially tangent to the line
perpendicular to the lower end 3a of the stem 3 intersecting the
stem lower end at the edge thereof. In order to maintain the same
ratio between the radius of the lower end 3a and the radius of the
upper end 3b for varying heights of the stem 3, the radius of
curvature of the arc-shaped profile of the stem 3 has to be
increased as a function of the stem height.
[0015] According to an important feature of the invention, optimum
results are obtained with the above described shape of the
reinforcing core 2 and using a metallic material with adequate
resistance and lightness, such as in particular the aluminium alloy
known as ERGAL 7075. Obviously materials having equivalent
mechanical features and lightness can be used as an
alternative.
[0016] The tests carried out on high heels according to the
aforementioned ISO standards, have shown that the resistance
requirements are widely fulfilled, in particular referring to the
repeated shear fatigue resistance test, which provides that the
resistance threshold is to be higher than 14,000 strokes.
[0017] Various modification and alterations to the invention may be
appreciated based on a review of the disclosure. These changes and
additions are intended to be within the scope and spirit of the
invention as defined by the following claims.
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