U.S. patent application number 14/812602 was filed with the patent office on 2015-11-19 for case for a mobile device with a screen.
The applicant listed for this patent is Tech 21 Licensing Limited. Invention is credited to Wilhelm MARSCHALL, Jason Lloyd ROBERTS, Benjamin THORPE.
Application Number | 20150327657 14/812602 |
Document ID | / |
Family ID | 50191714 |
Filed Date | 2015-11-19 |
United States Patent
Application |
20150327657 |
Kind Code |
A1 |
ROBERTS; Jason Lloyd ; et
al. |
November 19, 2015 |
CASE FOR A MOBILE DEVICE WITH A SCREEN
Abstract
A case for a mobile device with a screen, the case comprising a
band arranged to surround the edge of the device. The band
comprises a layer of flexible polymer and a layer of a damping
material which is softer than the flexible polymer provided within
the flexible polymer layer. The damping material has a plurality of
integrally formed protrusions projecting inwardly protrusions
projecting inwardly from a substantial portion of the inner
periphery of the band to engage with the device. The protrusions
are provided at least in the corner regions of the case and the
protrusions are arranged such that, in normal use there is
substantially no contact between the band and the device other than
through the protrusions.
Inventors: |
ROBERTS; Jason Lloyd;
(Twickenham, GB) ; MARSCHALL; Wilhelm;
(Twickenham, GB) ; THORPE; Benjamin; (Twickenham,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Tech 21 Licensing Limited |
Twickenham |
|
GB |
|
|
Family ID: |
50191714 |
Appl. No.: |
14/812602 |
Filed: |
July 29, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14586256 |
Dec 30, 2014 |
|
|
|
14812602 |
|
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Current U.S.
Class: |
224/191 |
Current CPC
Class: |
Y10T 428/1352 20150115;
H05K 5/0086 20130101; A45C 2011/002 20130101; B29C 70/68 20130101;
B29C 45/14336 20130101; A45C 2011/003 20130101; H04B 1/3888
20130101; A45F 5/00 20130101; A45C 11/00 20130101 |
International
Class: |
A45F 5/00 20060101
A45F005/00; A45C 11/00 20060101 A45C011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 3, 2014 |
GB |
1400079.8 |
Claims
1. A case for a mobile device with a screen, the case comprising a
band arranged to surround the edge of the device, the band
comprising a layer of flexible polymer and a layer of a damping
material which is softer than the flexible polymer provided within
the flexible polymer layer, the damping material having a plurality
of integrally formed protrusions projecting inwardly from a
substantial portion of the inner periphery of the band to engage
with the device, wherein the protrusions are arranged such that, in
normal use there is substantially no contact between the band and
the device other than through the protrusions; wherein the
protrusions are provided at least in the corner regions of the
case.
2. A case according to claim 1, wherein there are no protrusions,
or shorter protrusions along portions of the longer edges of the
case such that the case will not contact the device in these
regions in normal use.
3. A case according to claim 1, wherein the protrusions are ribs
extending generally across the depth of the band and have a curved
cross-section when viewed in a section taken in the plane of the
device.
4. A case according to claim 3, wherein the curved cross-section is
substantially semi-circular.
5. A case according to claim 1, wherein the damping material is
provided with a plurality of outwardly projecting protrusions which
are imbedded in the flexible polymer material.
6. A case according to claim 5, wherein the outwardly projecting
protrusions are ribs which are rectangular in cross-section when
viewed in a section taken in the plane of the device.
7. A case according to claim 1, wherein a layer of material harder
than the flexible polymer material is provided outside of the
flexible polymer material.
8. A case according to claim 1, wherein the flexible polymer layer
has a Shore A hardness range of 70 to 90.
9. A case according to claim 1, wherein the layer of damping
material has a Shore A hardness range of 0 to 70.
10. A case according to claim 7, wherein the layer of material
harder than the flexible polymer material has a hardness range of
75 Shore A to 85 Shore D.
11. A case according to claim 1, wherein the protrusions are robust
enough, so that, when dropped from 7 meters onto a hard surface,
the protrusions will prevent contact between the device and the
material between adjacent protrusions.
12. A case according to claim 1, wherein each protrusion protrudes
for a depth at least 0.5 mm from the band, has a width greater than
the depth and a pitch between adjacent protrusions which is greater
than twice the width.
13. A case according to claim 12, wherein the depth of each
protrusion is at least 1 mm.
14. A case according to claim 8, wherein the protrusions are robust
enough, so that, when dropped from 7 meters onto a hard surface,
the protrusions will prevent contact between the device and the
material between adjacent protrusions.
15. A case according to claim 9, wherein the protrusions are robust
enough, so that, when dropped from 7 meters onto a hard surface,
the protrusions will prevent contact between the device and the
material between adjacent protrusions.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/586,256 filed on Dec. 30, 2014, herein
incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a case for a mobile device
with a screen such as a smart phone, tablet or E-reader.
BACKGROUND OF THE INVENTION
[0003] It is well known to make such cases of thermoplastic
polyurethane (TPU) as this provides good durability for the case.
It does not, however, provide good impact protection for the device
as there is little dissipation of the impact and most of the energy
of the impact is transferred to the device. Known impact resistant
materials improve this to some extent.
[0004] The present invention aims to improve on this.
SUMMARY OF THE INVENTION
[0005] According to the present invention there is provided a case
for a mobile device with a screen, the case comprising a band
arranged to surround the edge of the device, the band comprising a
layer of flexible polymer and a layer of a damping material which
is softer than the flexible polymer provided within the flexible
polymer layer, the damping material having a plurality of
integrally formed protrusions projecting inwardly from a
substantial portion of the inner periphery of the band to engage
with the device, wherein the protrusions are arranged so that in
normal use there is substantially no contact between the band and
the device other than through the protrusions; wherein the
protrusions are provided at least in the corner regions of the
case.
[0006] Having protrusions in engagement with the majority of the
periphery of the device reduces significantly the contact area
between the device and the case to minimise energy transferred to
the device. The flexible polymer outer layer absorbs impact energy
and holds the shape of the case, while the softer material with the
protrusions further absorbs and dissipates the remaining energy of
the impact away from the device.
[0007] The contact with the protrusions is concentrated at
vulnerable regions such as the corners of the device. Portions of
the longer edges, or portions of edges where plugs sockets are
present may have no protrusions. Alternatively, shorter protrusions
may be provided along the longer edges of the case that will not
contact the device in normal use but will provide some cushioning
if the longer edges of the case are deflected inwardly.
[0008] The protrusions may have a number of configurations. They
may, for example be circular or annular projections extending
inwardly from the band. However, it has been found that the
preferred configuration is one in which the protrusions are ribs
extending generally across the depth of the band and have a curved
cross-section when viewed in a section taken in the plane of the
device. Preferably, the curved cross-section is substantially
semi-circular. Experiments have shown that such a shape can absorb
and dissipate high amounts of energy.
[0009] The case may consist only of the band. However, it may also
have a rear wall engaging with the back of the device. It may
further include a hinged cover to protect the screen.
[0010] The interface between the two materials may be planar.
However, preferably, the damping material is provided with a
plurality of outwardly projecting protrusions which are imbedded in
the flexible polymer.
[0011] The protrusions between the two materials improve the
cushioning and greatly increase energy absorption. The protrusions
may have the same configuration as the inwardly projecting ribs.
However, preferably, they are ribs which are rectangular in
cross-section when viewed in a section taken in the plane of the
device.
[0012] In order to further enhance impact protection, a layer of
material harder than the flexible polymer material (measured on the
Shore A hardness scale) may be provided outside of the flexible
polymer material. This provides a hard outer shell to further
spread the impact.
[0013] The flexible polymer may be TPE or TPU. The softer material
is preferably a viscoelastic material or an impact damping or
absorbing polymer.
[0014] The protrusions are preferably relatively robust in the
sense that when dropped from 7 meters onto a hard surface, the
protrusions will prevent contact between the device and the
material between adjacent protrusions.
[0015] This may be achieved by having relatively large ribs where,
preferably, each protrusion protrudes for a depth at least 0.5 mm
(more preferably 1 mm) from the band, has a width greater than the
depth and a pitch between adjacent protrusions which is greater
than twice the width.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Examples of cases in accordance with the present invention
will now be described by reference to the accompanying drawings, in
which:
[0017] FIG. 1 is a cross-section of a portion of a first case
included for background interest only in contact with the
device;
[0018] FIG. 2 is a similar view of a second case;
[0019] FIG. 3 is a similar view of a third case; and
[0020] FIG. 4 is a cross-section in the plane of the device of a
full case with the arrangement of FIG. 3.
DETAILED DESCRIPTION
[0021] FIG. 1 shows a small proportion of the case to illustrate
the principle of the present invention. The whole case will run
around the entire periphery of the device D.
[0022] The simplest design is typified in FIG. 1 which is a single
material 1, in this case TPU (for example BASF Elastollan), which
is provided with a number of inwardly extending ribs 2 which, as
shown, have a semi-circular cross-section in the plane of the
device and extend across the width of the band. The ribs in this
example have a width of 2 mm, a depth of 1.5 mm and a spacing of 3
mm.
[0023] The same basic structure is observed in FIG. 2 which is in
accordance with the invention, this time in a two part layer. The
TPU forms the outer layer while an inner layer 3 formed in a dual
injection process or as an insert mold is formed of a viscoelastic
polymer which is softer than the TPU (for example, a TPE such as
Kraiburg Thermolast K or a PU foam such as BASF Elastoflex). This
time, the inwardly projecting ribs 2 are provided in the
viscoelastic polymer layer 3. The viscoelastic polymer layer 3 also
has a number of inwardly projecting ribs 4 which are embedded in
the TPU layer 1.
[0024] The third case shown in FIG. 3 also in accordance with the
invention adds to the second case of FIG. 2, a hard outer shell 5
which is a rigid polymer case (for example Bayer Makrolon). As
shown in FIG. 3, this may only be present in certain regions where
higher hardness is beneficial.
[0025] The manner in which the example shown in FIG. 3 is applied
to a full case is shown with reference to FIG. 4. It will be
appreciated that the examples of FIGS. 1 and 2 can be applied in
the same manner, in the case of FIG. 2 omitting the outer shell 5,
and in the case of FIG. 1 with all of the case being formed of a
single layer of thermoplastic polymer 1.
[0026] In the full case shown in FIG. 4, the TPU material 1 forms
the bulk of the casing including the majority of the rear face 6.
This is lined with a layer of viscoelastic polymer 3 which extends
across a portion of the rear face 6 and up the sides of the
majority of the case. There are regions 7 and 8 in FIG. 4 where the
viscoelastic polymer is absent and the only material is the TPU so
as to allow access to the buttons in the side of the device in
region 7 and the ports for the charger plug and headphone jack in
region 8. The ribs 2 are present particularly at the corners of the
device to provide maximum cushioning in these regions. Running
along the majority of each side of the case are truncated ribs 2'
so that the case does not contact the device in these regions
during normal use thereby further isolating the sides from impact
on the screen.
[0027] The interface between the TPU 1 and viscoelastic polymer 5
has a plurality of rectangular ribs 9 protruding inwardly from the
viscoelastic polymer 5. These ribs 9 have a rectangular profile in
cross-section, the width of which is at least twice their
depth.
[0028] The case is completed by the rigid polymer layer 5 which
extends along the majority of each side of the case. There is also
a ring of rigid polymer 10 surrounding an orifice 11 which provides
a window for the rear facing camera, sensor and LED flash.
[0029] As can be seen from FIG. 4, the casing is designed to
provide maximum cushioning in the corner regions. However, along
the long side portions, the case is largely held away from the
device and has enhanced rigidity afforded by the rigid polymer
layer 5.
* * * * *