U.S. patent application number 11/885775 was filed with the patent office on 2008-07-10 for reinforced toe-cap for safety footwear.
Invention is credited to Valter Bozzetto, Leo Sartor.
Application Number | 20080163519 11/885775 |
Document ID | / |
Family ID | 36124466 |
Filed Date | 2008-07-10 |
United States Patent
Application |
20080163519 |
Kind Code |
A1 |
Sartor; Leo ; et
al. |
July 10, 2008 |
Reinforced Toe-Cap for Safety Footwear
Abstract
A reinforced toe-cap (1, 100, 200) for safety footwear comprises
a body (2) in which a top region (5) and a front toe region (4) are
defined; a protuberance (6, 106, 206) is defined on the body in the
top region, projecting from the profile of the top region.
Inventors: |
Sartor; Leo; (Montebelluna,
IT) ; Bozzetto; Valter; (Santa Lucia Di Piave,
IT) |
Correspondence
Address: |
GOTTLIEB RACKMAN & REISMAN PC
270 MADISON AVENUE, 8TH FLOOR
NEW YORK
NY
10016-0601
US
|
Family ID: |
36124466 |
Appl. No.: |
11/885775 |
Filed: |
February 3, 2006 |
PCT Filed: |
February 3, 2006 |
PCT NO: |
PCT/EP2006/000942 |
371 Date: |
September 6, 2007 |
Current U.S.
Class: |
36/77M ; 36/72R;
36/77R |
Current CPC
Class: |
A43C 13/14 20130101;
A43B 23/086 20130101 |
Class at
Publication: |
36/77.M ;
36/77.R; 36/72.R |
International
Class: |
A43B 23/08 20060101
A43B023/08; A43B 13/22 20060101 A43B013/22 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2005 |
IT |
PD2005A000084 |
Claims
1. A reinforced toe-cap for safety footwear, comprising a body in
which a top region and a front region are defined, and wherein a
protuberance is defined on the body, the protuberance projecting
from the profile of the top region and/or of the front region.
2. A toe-cap according to claim 1 in which the protuberance has a
height of between 1 and 5 mm relative to the profile of the top
region.
3. A toe-cap according to claim 1 in which the protuberance has
dimensions at the base of between 10 and 40 mm.
4. A toe-cap according to claim 1 in which the protuberance is
formed on the top region at a distance of between 10 and 35 mm from
the end of the front region.
5. A toe-cap according to claim 1 in which the protuberance is
formed integrally on the body.
6. A toe-cap according to claim 5 in which the body and the
protuberance are formed simultaneously by injection and moulding of
plastics material.
7. A toe-cap according to claim 1 in which the protuberance is made
of material different from the material of which the body is
made.
8. A toe-cap according to claim 7 in which the protuberance is made
of metal, of plastics material, or of composite material.
9. A toe-cap according to claim 7 in which the protuberance is
produced by the moulding onto the body of a plastics material
different from the material of which the body is made.
10. A toe-cap according to claim 1 in which the protuberance is
produced by the fitting of a separate supplementary piece onto the
body.
11. A toe-cap according to claim 1 in which a closed chamber
remains between the body and the protuberance.
12. A toe-cap according claim 1 in which a viscoelastic or
elastomeric material or a substantially inextensible,
tear-resistant material is interposed between the protuberance and
the body.
13. A toe-cap according to claim 1 in which a fabric of
tear-resistant and substantially inextensible material is
superimposed on the protuberance.
14. A toe-cap according to claim 12 in which the fabric of
substantially inextensible, tear-resistant material extends in a
closed loop around the body.
15. A toe-cap according to claim 13 in which the fabric of
substantially inextensible, tear-resistant material extends in a
closed loop around the body.
16. A kit for the production of a reinforced toe-cap for safety
footwear, the kit comprising a body and at least one supplementary
piece which can be fitted onto the body so as to project from the
profile of the body.
17. A kit according to claim 16 in which a plurality of the said
supplementary pieces are provided, at least two of the said
supplementary pieces being made of different materials.
Description
TECHNICAL FIELD
[0001] The present invention relates to a reinforced toe-cap for
safety footwear according to the characteristics set forth in the
preamble to the main claim. It is also directed towards a kit for
the production of a reinforced toe-cap.
BACKGROUND ART
[0002] In the technical field to which the invention relates,
reinforcing toe-caps to be inserted so as to fit in toe regions of
safety footwear are known.
[0003] Since these toe-caps are intended to protect the ends of the
feet, they have to be able to withstand the impact of predetermined
falling loads without breaking and without undergoing significant
deformation in accordance with standard tests for evaluating the
strength of these items. In order to offer the mechanical
properties that are necessary to pass the required strength tests,
it is known to make the toe-caps of metal or plastics material or
even of composite material.
[0004] However, each of the above-mentioned types has some
disadvantages. In fact metal toe-caps are generally heavy and are
also unsuitable for some uses including use in locations in which
there may be metal-sensitive apparatus (for example, metal
detectors) or in locations in which there is a need to withstand
very high or very low temperatures, given the high thermal
conductivity of metals. As far as toe-caps made of plastics
materials are concerned, they generally have to have considerable
thicknesses in order to offer the required mechanical strength, to
the detriment of the dimensions and comfort of the footwear in
which they are fitted. Finally, the use of reinforcing toe-caps
made of composite material is limited by the relatively high
production cost.
[0005] Reinforcing toe-caps having particular shapes, for example,
with variable thickness along the cross-section of the toe-cap, are
also known.
DESCRIPTION OF THE INVENTION
[0006] The problem underlying the present invention is that of
providing a reinforcing toe-cap for safety footwear that is
designed structurally and functionally to overcome the limitations
set out above with reference to the prior art mentioned.
[0007] This problem is achieved by the present invention by means
of a reinforcing toe-cap formed in accordance with the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The characteristics and the advantages of the invention will
become clearer from the detailed description of some preferred
embodiments thereof which are described by way of non-limiting
example with reference to the appended drawings, in which:
[0009] FIG. 1 is a perspective view of a reinforcing toe-cap formed
in accordance with the present invention,
[0010] FIG. 2 is a longitudinal section through the toe-cap of FIG.
1,
[0011] FIG. 3 is a longitudinal section through a second embodiment
of a reinforcing toe-cap formed in accordance with the present
invention,
[0012] FIG. 4 is an exploded longitudinal section through a third
embodiment of a reinforcing toe-cap formed in accordance with the
present invention,
[0013] FIG. 5 is a longitudinal section through the toe-cap of FIG.
4 in the assembled condition.
PREFERRED EMBODIMENTS OF THE INVENTION
[0014] With reference initially to FIGS. 1 and 2, a reinforcing
toe-cap for safety footwear formed in accordance with the present
invention is generally indicated 1.
[0015] The toe-cap 1 is intended to be connected, by conventional
techniques, to a sole and/or to the upper of a safety shoe or boot,
not shown.
[0016] The toe-cap 1 comprises a body 2 which is generally in the
shape of a half-shell that is open on one side in the region of an
opening 3 through which the user's foot is inserted; the half-shell
is closed at the opposite end by a front region 4 of the
toe-cap.
[0017] A top region 5 extends and is defined between the opening 3
and the front region 4 which is intended to face the end of the
foot in use; the top region 5 is connected to the front region 4
and is intended to face the upper surface of the foot in use.
[0018] A terminal portion 2a of soft material such as, for example,
rubber preferably also extends from the opening 3 of the body 2 to
improve the comfort of the footwear.
[0019] According to a first aspect of the invention, a protuberance
6 is formed on the body 2, the protuberance projecting from the
natural profile defined by the curvature of the toe-cap. For
clarity, the natural profile of the toe-cap is indicated by a
broken line in the section of FIG. 2.
[0020] In this context, the term "protuberance" therefore adopts
the generally accepted meaning which, in an attempt to give it a
greater geometrical connotation, could be defined as a surface
portion which comprises a maximum of curvature and is joined at
least to a portion of the surrounding surface by a concave
connecting region, or by a region of discontinuity of
curvature.
[0021] The protuberance 6 is preferably formed on the top region 5
at a distance S of between 10 and 35 mm from the end of the front
region 4, but it may also usefully be formed on the front region,
as explained further below.
[0022] The body 2 is preferably produced by the technique of
injection and moulding of a plastics material such as, for example,
polycarbonate, polyamide, polypropylene, polyethylene or other
polyolefins. However, it may also advantageously be made of other
materials that are conventionally used in the field in question,
such as metals or composite materials. The latter are preferably of
the type with woven or non-woven long fibres impregnated with a
thermosetting or thermoplastic resin matrix.
[0023] In the first embodiment of the invention described herein,
the protuberance 6 is produced integrally with the body 2 and
preferably has a lenticular shape with a generally elliptical base
plan and with the following dimensions: height H relative to the
profile of the top region of between 1 and 5 mm; both longitudinal
and transverse dimensions L of the base of between 10 and 40
mm.
[0024] The protuberance 6 may, however, be circular in plan or may
have other shapes more complex than that shown in the appended
drawings. For example, it may extend longitudinally along the top
region 5 possibly also extending over the front region 4, it may
extend longitudinally in a central position or in an offset
position, or it may have an arcuate base plan or a flatter profile,
for example, with a trapezoidal cross-section.
[0025] Moreover, two or more protuberances may also be provided,
extending on the top region 5 and/or the front region 4 parallel to
one another or intersecting one another.
[0026] To compare the properties of toe-caps formed in accordance
with the present invention with those produced conventionally, that
is, without protuberances on the top region, the Applicant has
carried out a series of tests to demonstrate their impact
strength.
[0027] A test typically used to check the impact strength consists
in dropping a metal gravity body having a predefined weight
(normally 20 kg), on edge, from a predetermined height (normally 1
metre), onto the toe-cap to be tested (ISO standard
20345/2003).
[0028] The test is considered to be passed if the maximum
deformation caused in the toe-cap by the impact with the gravity
body is below a predetermined threshold and the toe-cap does not
have significant cracks. In this case the toe-cap would in fact be
able to perform the function of protecting the user's foot in a
positive manner.
[0029] Naturally, the toe-caps of both types were produced by the
injection and moulding of the same plastics material, in the
specific case, polycarbonate.
[0030] The results of the tests showed that the presence of the
protuberance 6 conferred on the toe-cap 1 a greater ability to
withstand impacts by falling gravity bodies which was quantifiable
as an increase of about 10%-15%.
[0031] Although it is not desired to be bound to a particular
theory, the favourable results obtained might be explained by the
fact that, for a given material and thickness, the impact is
absorbed better by a structure having a more marked curvature in
comparison with a flatter structure, since a significant component
of the forces discharged onto the toe-cap by the impact with the
gravity body is discharged towards the side walls of the toe-cap
and by the side walls to the sole. With the low-curvature surface
of conventional toe-caps, on the other hand, the component of the
force which has to be absorbed by the region of the toe-cap
corresponding to the impact is much greater and this consequently
causes the greater deformation of the material.
[0032] Moreover, it should be noted that, in conventional toe-caps,
the region of lesser curvature is often precisely the top region
where the likelihood of an impact by a load falling from above is
greatest and therefore where the protective function of the toe-cap
is most important.
[0033] The impact strength of the top region can thus be increased
without increasing the thickness of the layer of plastics
material.
[0034] In the above-mentioned case in which the protuberance is
formed in the front region 4, the toe-cap naturally adopts a
greater impact strength in that region. This may be useful when the
footwear in which the toe-cap is to be fitted is required to offer
a particular impact strength in that specific region. This is the
case, for example, in footwear used by firemen which have to be
capable of being used to kick down obstacles (for example, a
door).
[0035] FIG. 3 shows a reinforcing toe-cap 100 constituting a second
embodiment of the invention in which similar details have the same
reference numerals as in the embodiment described above.
[0036] The toe-cap 100 comprises a protuberance 106 which is
produced by being moulded onto the previously-produced body 2.
[0037] The protuberance 106 can thus advantageously be moulded on
with a plastics material different from that used to produce the
body 2, thus permitting greater freedom in the selection of the
materials to be used in accordance with appropriate considerations
of economy, type of application, and efficiency of performance. For
example, the protuberance may advantageously be made of
polycarbonate or of polyamide and the body 2 of less expensive
polypropylene.
[0038] FIGS. 4 and 5 show generally a reinforcing toe-cap 200
constituting a third embodiment of the invention in which similar
details have the same reference numerals as in the embodiment
described above.
[0039] In the toe-cap 200, the protuberance is produced by
connecting a supplementary piece 206 to the body 2. These elements
are produced separately and independently and can be connected, for
example, by gluing.
[0040] The supplementary piece 206 may advantageously be made of
any material that is considered suitable, including plastics
material, for example, those mentioned above, a metal, a composite
material, etc.
[0041] In this embodiment, a closed chamber 207 is defined between
the supplementary piece 206 and the body 2. This structure is
generally stronger, given that the overall impact strength in the
region of the protuberance is determined both by the presence of
the supplementary piece 206 and by the presence of the body 2.
[0042] According to a first variant of the invention, a material
having viscoelastic or elastomeric properties, such as, for
example, silicone or thermoplastic, vulcanized or even expanded
rubbers, may be provided in the closed chamber 207.
[0043] According to a second variant of the invention, a layer of
tear-resistant and substantially inextensible material, for
example, an aramidic-fibre fabric such as the material known by the
trade name of Kevlar.RTM., is interposed between the supplementary
piece 206 and the body 2.
[0044] These measures further improve the impact strength of the
toe-cap 100.
[0045] In fact, tests carried out by the Applicant have shown that
the interposition of a viscoelastic or elastomeric layer or of an
aramidic-fibre fabric increases the impact strength of the toe-caps
by a fraction quantifiable as between 15% and 20%.
[0046] As well as providing finished toe-caps in which the body and
the toe-cap are already connected to one another, this latter
embodiment of the invention advantageously permits the production
of safety toe-caps from separate elements which are made of
different materials and which can be combined with one another in
various ways to produce toe-caps that are individualized according
to the specific field of application of the safety footwear in
which they are to be fitted.
[0047] The body 2 will generally be produced by injection and
moulding of plastics material, whereas the supplementary piece 206
that can be connected to the body 2 will be available in plastics
material with better mechanical characteristics (polycarbonate,
polyamides, ABS, and other techno-polymers), or in metal, or even
in composite material.
[0048] It is thus possible to provide kits suitable for the
production of a reinforced toe-cap for safety footwear and
comprising a body made of plastics material and one or more
supplementary pieces made of different materials each arranged to
be connected to the body 2. This operation can be performed by the
safety footwear manufacturer who may in general be other than the
manufacturer of the toe-caps. In this latter case, moreover, the
capability is provided for a supplementary piece that has been
damaged as a result of an impact to be replaced-by another
supplementary piece without replacing the entire shoe or boot.
[0049] According to a variant of the present invention which is
applicable in the same manner to all of the embodiments described
above, a layer of tear-resistant and substantially inextensible
material such as an aramidic-fibre fabric, for example, Kevlar.RTM.
may be applied firmly on top of the protuberance 6, 106, and 206.
The toe-caps thus obtained have clear improvements, at least of the
order of 10%-20%, in terms of impact strength.
[0050] This advantageous effect can reasonably be attributed to the
fact that, by virtue of the presence of the aramidic-fibre fabric,
the stresses resulting from the impact, which is extremely
localized, are distributed over a much larger area. In fact it is
pointed out that a localized deformation of the body 2 translates
into a tensile load on the fabric between the deformed region and
the non-deformed (or less deformed) region and into a shearing
stress between the fabric and the surface of the body that is in
contact with the fabric. However, these loads are resisted by the
properties of tensile strength and very low percentage extension
which characterize aramidic fibres and by the adhesion force
between the fabric and the body.
[0051] The aramidic-fibre fabric may also be wrapped around the
body 2 so as to be closed in a loop around the body without breaks
in continuity. Greater lateral limitation of deformation of the
toe-cap is thus achieved, resulting in a further increase in impact
strength.
[0052] The present invention thus solves the problem discussed with
reference to the prior art mentioned, at the same time offering
many further advantages.
* * * * *