U.S. patent application number 09/753477 was filed with the patent office on 2002-07-04 for co-molded fastening devices.
Invention is credited to Lerra, Christopher G..
Application Number | 20020083562 09/753477 |
Document ID | / |
Family ID | 25030797 |
Filed Date | 2002-07-04 |
United States Patent
Application |
20020083562 |
Kind Code |
A1 |
Lerra, Christopher G. |
July 4, 2002 |
Co-molded fastening devices
Abstract
Co-molded fastening devices are provided, including a rigid body
and, co-molded with and extending from a portion of the body, a
resilient element constructed to provide a user of the device with
an improved grip on the device or improved comfort.
Inventors: |
Lerra, Christopher G.;
(Manchester, NH) |
Correspondence
Address: |
JAMES W. BABINEAU
Fish & Richardson P. C.
225 Franklin Street
Boston
MA
02110-2804
US
|
Family ID: |
25030797 |
Appl. No.: |
09/753477 |
Filed: |
January 3, 2001 |
Current U.S.
Class: |
24/115G |
Current CPC
Class: |
A44B 11/266 20130101;
Y10T 24/3984 20150115 |
Class at
Publication: |
24/115.00G |
International
Class: |
A44B 011/25; A44B
021/00 |
Claims
What is claimed is:
1. A co-molded fastening device comprising a rigid body and,
co-molded with and extending from a portion of the body, a
resilient element constructed to provide a user of the device with
an improved grip on the device or improved comfort.
2. The co-molded fastening device of claim 1 wherein the fastening
device comprises a quick release buckle.
3. The co-molded fastening device of claim 2 wherein the quick
release buckle comprises a side release buckle.
4. The co-molded fastening device of claim 1 wherein the fastening
device comprises a cord lock.
5. The co-molded fastening device of claim 1 wherein the fastening
device is selected from the group consisting of D-ring buckles,
loop buckles, triangular buckles, snap hooks, press buckles, slide
buckles and step lock buckles, and shoulder pads.
6. The co-molded fastening device of claim 1 wherein said resilient
element has a hardness of from about 20 to 100 Shore A.
7. The co-molded fastening device of claim 2 wherein said quick
release buckle comprises a male buckle element and a female buckle
element constructed for releasable engagement with the male buckle
element, and the resilient element is positioned on the female
buckle element.
8. The co-molded fastening device of claim 7 wherein the resilient
element is positioned so as to prevent a user's skin from being
pinched between the male and female buckle elements when they are
engaged with each other.
9. The co-molded fastening device of claim 1 wherein the body
comprises a rigid plastic having a hardness of from about 40 to 90
Shore D.
10. A method of manufacturing a co-molded fastening device having a
body and a resilient element extending from a surface of the body,
comprising introducing a first resin into a first mold cavity of an
injection mold with moving plates that are movable between a first
position, in which the plates define the first mold cavity, and a
second position, in which the plates define a second mold cavity
adjacent the first, moving the plates to the second position, and
injecting a second resin into the second mold cavity.
Description
TECHNICAL FIELD
[0001] This invention relates to co-molded fastening devices, and
more particularly to plastic buckles such as quick release buckles
and cord-locks
BACKGROUND
[0002] Many types of fastening devices are formed of molded
plastic. Examples of molded fastening devices include quick release
buckles, cord-locks, D-ring buckles, loop buckles, triangular
buckles, snap hooks, press buckles, slide buckles and step lock
buckles, and shoulder pads. Such fastening devices are generally
molded from a smooth, rigid plastic such as polyethylene, acetal or
nylon.
[0003] In applications such as backpacks and luggage, quick release
buckles are used to fasten webbing straps together. Such buckles
are easily and quickly fastened and unfastened and, in some cases,
provide adjustability of the length of one or both of the straps.
In a backpack the quick release buckles are used, for example, to
fasten the belt of the pack around the wearer's waist, to fasten a
sternum strap around the wearer's chest and, in some cases, to
provide releasable, adjustable length compression straps along the
sides of the pack. In luggage the buckles are used, e.g., to
releasably secure a removable shoulder strap to a gym bag, duffle
bag or briefcase. In some applications the buckle may come into
direct contact with the user's skin, for example when the buckle is
used to secure the chin strap of a bike helmet.
[0004] Lengths of cord or drawstring are often adjustably secured
with a cord-lock. Cord-lock devices provide a convenient way to
secure and adjust cord, but may be difficult for some users to
manipulate with finger pressure, due to their small size.
SUMMARY
[0005] The inventor has found that the functionality, comfort and
aesthetic qualities of fastening devices, such as those described
above, can be significantly improved by co-molding these devices to
include a relatively rigid base and one or more resilient portions.
The resilient portions of the fastening device provide a gripping
surface that is easier to grasp and manipulate than a smooth, rigid
plastic surface. This allows small, difficult to grasp devices such
as cord-locks to be more easily operated. Moreover, the resilient
portions may provide improved user comfort, particularly when the
device contacts a wearer's skin during use, for example when the
device is a quick release buckle for the chin strap of a bicycle
helmet, or a sternum strap for a backpack.
[0006] In one aspect, the invention features a co-molded fastening
device including a rigid body and, co-molded with and extending
from a portion of the body, a resilient element constructed to
provide a user of the device with an improved grip on the device or
improved comfort.
[0007] Implementations of the invention may include one or more of
the following features. The fastening device includes a quick
release buckle, e.g., a side release buckle, or a cord lock. The
fastening device is selected from the group consisting of D-ring
buckles, loop buckles, triangular buckles, snap hooks, press
buckles, slide buckles and step lock buckles, and shoulder pads.
The resilient element has a hardness of from about 20 to 100 Shore
A. The quick release buckle includes a male buckle element and a
female buckle element constructed for releasable engagement with
the male buckle element, and the resilient element is positioned on
the female buckle element. The resilient element is positioned so
as to prevent a user's skin from being pinched between the male and
female buckle elements when they are engaged with each other. The
body includes a rigid plastic having a hardness of from about 40 to
90 Shore D.
[0008] In another aspect, the invention features a method of
manufacturing a co-molded fastening device having a body and a
resilient element extending from a surface of the body, including
(a) introducing a first resin into a first mold cavity of an
injection mold with moving plates that are movable between a first
position, in which the plates define the first mold cavity, and a
second position, in which the plates define a second mold cavity
adjacent the first, (b) moving the plates to the second position,
and (c) injecting a second resin into the second mold cavity.
[0009] The term "fastening device", as used herein, includes not
only devices that fasten components together, but also other types
of molded hardware that are constructed to receive webbing or cord
for other purposes such as adjustment, securement and cushioning,
e.g., slide buckles and shoulder pads.
[0010] Other features and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a perspective view of a quick release buckle
according to one aspect of the invention.
[0012] FIG. 1A is a front plan view of the quick release buckle of
FIG. 1.
[0013] FIG. 1B is a schematic rear plan view of the female buckle
element of the quick release buckle of FIG. 1.
[0014] FIG. 1C is a schematic side view of the female buckle
element.
[0015] FIG. 1D is a perspective view of a female buckle element
according to an alternate embodiment of the invention.
[0016] FIG. 2 is a perspective view of a cord-lock according to one
aspect of the invention.
[0017] FIGS. 2A and 2B are, respectively, front and end plan views
of the cord-lock of FIG. 2.
[0018] FIG. 3 is a top view of a shoulder pad.
[0019] FIG. 4 is a side view of a snap hook according to one
embodiment of the invention.
[0020] FIGS. 5 and 5A are front and side views of a snap hook
according to another embodiment of the invention.
[0021] FIG. 6 is a front planar view of a triangular buckle.
[0022] FIG. 7 is a front planar view of a rectangular loop
buckle.
[0023] FIG. 8 is a front planar view of a slid e buckle.
[0024] FIG. 9 is a front planar view of a step lock buckle.
[0025] FIG. 10 is a top view of a press buckle.
[0026] FIG. 11 is a front planar view of a D-ring buckle.
DETAILED DESCRIPTION
[0027] Referring to FIGS. 1 and 1A, a quick release buckle 10
includes a pair of engageable male and female buckle elements 12
and 14. Male buckle element 12 includes a pair of prongs 16 that
releasably engage side-release openings 18 of female buckle element
14, as is well known in the quick release buckle art.
[0028] The female buckle element 14 includes a resilient portion 20
that is formed of a relatively soft, resilient material. A similar
resilient portion 21 is provided on the reverse side of the female
buckle element, as shown in FIGS. 1B-1C. A flap 19 of the resilient
portion 21 extends beyond edge 23 of the female buckle element, to
prevent a user's skin from being pinched between the male and
female buckle elements when they are snapped together. This feature
is particularly useful when the buckle is used to secure a chin
strap, e.g., of a bicycle helmet. The remainder of the quick
release buckle is formed of a rigid or semi-rigid base material
having a relatively smooth surface. In an alternate embodiment,
shown in FIG. 1D, the resilient portion 21 includes side regions 25
that extend beyond the side-release openings 18 to protect the user
from pinching in these areas.
[0029] Resilient portions 20 and 21 provide the quick release
buckle with improved tactile qualities, making it easier to grasp
securely, and thus facilitating cooperative engagement of the two
buckle elements by a user. Moreover, the resilient portions 20, 21
provide a relatively soft surface, thereby improving user comfort
if the quick release buckle is used in an application in which it
will contact the user's skin during use, e.g., as the buckle on a
chin strap of a helmet. The resilient portion preferably has a
thickness of from about 0.5 to 2.5 mm.
[0030] Referring to FIGS. 2-2B, cord-lock 40 includes male and
female cylindrical members 42, 44 having corresponding apertures
46, 48 which can be moved into alignment to define a bore for
receiving a cord. The apertures are biased out of alignment, as
shown, by a spring 50. The apertures are moved into alignment by
pressing end surfaces 52, 54 towards each other (arrows A, FIG. 2A)
to overcome the biasing force of the spring. When the apertures are
aligned, one or more ends of a cord may be threaded through the
resulting bore. The length of the cord on either side of the
cord-lock can be adjusted by again pressing surfaces 52, 54
together to release the hold of the cord-lock on the cord.
[0031] The end surfaces 52, 54 are cushioned by resilient portions
56, 58. The resilient portions provide the user with an improved
grip on the cord-lock, making it easier to initially grasp and
orient the cord-lock, and to keep a secure grip on the cord-lock
during operation. The resilient portions also improve user comfort
when pressure is applied to the end surfaces. Preferably, the
resilient portions each have a thickness of from about 0.5 to 2.5
mm. It is also preferred that the resilient portions have a beveled
edge 60, as shown, to provide a smooth contour and further enhance
user comfort.
[0032] Suitable materials for the base of the fastening device
include rigid and semi-rigid moldable plastics such as polyacetals,
acrylonitrile butadiene styrene (ABS), polyamides such as NYLON
6/6, and polyolefins such as polyethylene and polypropylene.
Preferably, the base material has a hardness of at least 40 Shore
D, more preferably from about 40 to 90 Shore D.
[0033] Suitable materials for the resilient portions of the
fastening device include thermoplastic elastomers (TPEs). Suitable
TPEs include thermoplastic vulcanates (rubber polyolefin blends),
polyetheramides, polyesters, styrene-ethylene-butylene-styrene
(SEBS) block copolymers, styrene-butadiene-styrene (SBS) block
copolymers, partially or fully hydrogenated
styrene-butadiene-styrene block copolymers,
styrene-isoprene-styrene (SIS) block copolymers, partially or fully
hydrogenated styrene-isoprene-styrene block copolymers,
polyurethanes, polyolefm elastomers, polyolefin plastomers,
styrenic based polyolefin elastomers, compatible mixtures thereof,
and similar thermoplastic elastomers. SEBS, SBS and SIS block
copolymers are commercially available from Shell under the
tradename KRATON rubber. Other suitable resilient materials include
resilient urethanes, silicones and foams. Suitable foams include
polyurethane foams, e.g., those prepared from compositions having
two components: a foamable, curable polyurethane prepolymer, and an
aqueous phase containing a latex and a surfactant. The resilient
material may include additives, such as plasticizers, fillers or
pigments. The additive may be selected to provide the resilient
material with a desired surface texture.
[0034] Preferred resilient materials are durable enough to
withstand use during the lifetime of the fastening device without
tearing or abrading, and hard enough to provide a secure-feeling
grip, while also being sufficiently soft to provide a comfortable
degree of cushioning and good tactile properties during use.
Preferred materials have a hardness of less than about 100 Shore A,
more preferably from about 20 to 100 Shore A.
[0035] The base material and resilient material can be co-molded
using conventional co-molding techniques. For example, an injection
mold with moving plates may be used, in which case one of the
materials is introduced into the mold cavity with the plates in a
first position, and the plates are then moved to a second position
prior to introduction of the other material. This type of injection
molding equipment is well known in the molding field, and utilizes
two separate melt barrels to facilitate two different materials
being melted into a single mold.
[0036] Examples of other types of molded fastening devices that
benefit from the inclusion of resilient elements are shown in FIGS.
3-11.
[0037] FIG. 3 shows a shoulder pad 70, e.g., for receiving the
webbing strap of a duffle bag (not shown). The side edges 72 of the
shoulder pad include resilient portions 120, to prevent the
shoulder pad from cutting into a user's shoulder. The resilient
portions improve comfort in the shoulder area by softening side
edges 72 to reduce the tendency of the side edges to dig into the
shoulder if the webbing strap is rotated or twisted. The shoulder
pad may also include a resilient portion on its back surface (not
shown), to provide further cushioning. It a resilient portion is
provided on the back surface it may be coextensive with resilient
portions 120 or separate therefrom.
[0038] FIG. 4 shows a snap hook 80 according to one embodiment of
the invention, and FIGS. 5 and 5A show a snap hook 80' according to
another embodiment of the invention. Snap hook 80 is relatively
small, e.g., for use as a glove hook for engagement with a small
D-ring on a corresponding glove. The resilient areas 120 improve
the user's grip on the snap hook when engaging it with a D-ring or
other element, and improves comfort in applications in which the
snap hook contacts a user's skin.
[0039] FIG. 6 shows a triangular buckle 85, and FIG. 7 shows a
rectangular loop buckle 90. FIG. 8 shows a slide buckle 95. FIG. 9
shows a step lock buckle 125. FIG. 10 shows a press buckle 130.
FIG. 11 shows a D-ring buckle 135. Each of these devices includes a
rigid body 100 and one or more resilient portions 120 mounted on
the body. In each of these devices, resilient portions 120 are
positioned to provide a user with a more secure grip on the device,
to improve the aesthetic appeal of the device, and/or to improve
comfort if the device is used in an application where it will
contact a user's skin. In some cases, the resilient portions 120
may serve to reduce abrasion of a material that the device will rub
against when in use, and/or provide a more secure grip for cinching
straps or webbing that pass through the device. In the case of
D-ring buckle 135, the resilient areas could be used to prevent or
reduce movement of a snap hook around the buckle once the snap hook
and buckle are engaged.
[0040] Other embodiments are within the scope of the following
claims. For example, other types of fastening devices can be
co-molded as described above. Moreover, the resilient portions may
be provided on other areas of the fastening devices, depending upon
the function or aesthetic qualities that are desired for a
particular application. Where more than one resilient portion is
provided on a device, the resilient portions may have different
colors, surface textures and/or hardnesses. Similarly, the
resilient element may be of a color different from that of the body
of the fastening device. The resilient element may have any desired
shape, including that of a letter, logo or design.
* * * * *