U.S. patent application number 10/481284 was filed with the patent office on 2004-12-02 for housing construction.
Invention is credited to Tang, Thomas, Tat, Tee Chin.
Application Number | 20040237422 10/481284 |
Document ID | / |
Family ID | 8182068 |
Filed Date | 2004-12-02 |
United States Patent
Application |
20040237422 |
Kind Code |
A1 |
Tat, Tee Chin ; et
al. |
December 2, 2004 |
Housing construction
Abstract
A method for manufacturing an equipment housing, comprising:
locating together a first housing part (1) and a second housing
part (2) so that the first housing part overlaps the second housing
part at a join (15) between the housing parts; and irradiating the
region of the join with radiation to which the first housing part
is substantially transparent and the second housing part (2) is
absorptive so as to heat the second housing part and fuse the
housing parts (1,2) together at the join (15).
Inventors: |
Tat, Tee Chin; (Singapore,
SG) ; Tang, Thomas; (Singapore, SG) |
Correspondence
Address: |
PERMAN & GREEN
425 POST ROAD
FAIRFIELD
CT
06824
US
|
Family ID: |
8182068 |
Appl. No.: |
10/481284 |
Filed: |
July 2, 2004 |
PCT Filed: |
June 28, 2002 |
PCT NO: |
PCT/IB02/03182 |
Current U.S.
Class: |
52/79.1 ;
52/745.08 |
Current CPC
Class: |
B29C 65/72 20130101;
B29C 65/7855 20130101; B29K 2995/0027 20130101; B29C 66/1162
20130101; B29C 66/112 20130101; B29C 66/14 20130101; B29C 65/1677
20130101; B29C 66/12841 20130101; B29C 66/73921 20130101; B29C
65/1412 20130101; B29C 65/58 20130101; B29C 65/1435 20130101; B29C
66/1282 20130101; B29C 65/08 20130101; B29C 66/71 20130101; B29C
66/543 20130101; B29C 65/1635 20130101; B29C 65/1674 20130101; H04M
1/0249 20130101; B29C 66/863 20130101; B29C 66/1286 20130101; B29C
66/5346 20130101; B29C 66/71 20130101; B29C 66/542 20130101; B29C
66/1142 20130101; B29C 66/1122 20130101; B29C 66/71 20130101; B29K
2069/00 20130101; B29K 2055/02 20130101; B29K 2033/12 20130101;
B29C 65/1654 20130101; B29C 66/114 20130101; B29C 65/1638 20130101;
B29C 66/71 20130101; B23K 26/244 20151001; B29C 66/124
20130101 |
Class at
Publication: |
052/079.1 ;
052/745.08 |
International
Class: |
E04H 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 29, 2001 |
EP |
01305691.6 |
Claims
1. A method for manufacturing an equipment housing, comprising:
locating together a first housing part and a second housing part so
that the first housing part overlaps the second housing part at a
join between the housing parts; and irradiating the region of the
join with radiation to which the first housing part is
substantially transparent and the second housing part is absorptive
so as to heat the second housing part and fuse the housing parts
together at the join.
2. A method as claimed in claim 1, wherein the first housing part
is located outward of the second housing part at the join.
3. A method as claimed in claim 1, wherein the second housing part
includes a display opening.
4. A method as claimed in claim 1, wherein the first housing part
is a back cover of the housing and the second housing part is a
front cover of the housing.
5. A method as claimed in claim 1, wherein the first housing part
is a transparent display window.
6. A method as claimed in claim 5, wherein the second housing part
is a front cover of the housing.
7. A method as claimed in claim 1, wherein the radiation is laser
light.
8. A method as claimed in claim 7, wherein the wavelength of the
laser light is in the non-visible part of the spectrum.
9. A method as claimed in claim 1, wherein the irradiation step is
performed so as to generate insufficient heat to melt the outer
surface of the first housing part.
10. A method as claimed in claim 1, comprising the steps of:
locating together a third housing part and the second housing part
so that the third housing part overlaps the second housing part at
a join between the second and third housing parts; and irradiating
the region of the join between the second and third housing parts
with radiation to which the third housing part is substantially
transparent and the second housing part is absorptive so as to heat
the second housing part and fuse the second and third housing parts
together at the join.
11. A method as claimed in claim 1, wherein the housing is a
housing for a portable electronic device.
12. A method as claimed in claim 1, wherein the housing is a
housing for a mobile phone.
13. A method as claimed in claim 1, wherein the housing is a
housing for a portable electronic device.
14. An equipment housing comprising a first housing part and a
second housing part located so that the first housing part overlaps
the second housing part at a join between the housing parts; and
the parts being laser welded together at the join.
15. An equipment housing as claimed in claim 12, wherein the first
housing part is located outward of the second housing part at the
join.
16. An equipment housing as claimed in claim 13, wherein the welded
zone does not extend to the outer surface of the first housing
part.
17. Canceled
18. Canceled
Description
[0001] This invention relates to a housing construction and a
method for joining housing parts together.
[0002] FIG. 1 shows a mobile phone, and FIG. 2 shows a
cross-section on line A-A of FIG. 1. The mobile phone has a housing
that comprises a front or A cover 1, a back or B cover 2 and a
window 6. The A cover and the B cover enclose a space 8 inside the
housing in which are located a display 4 and other electronic
components 7. The display is located opposite an opening in the A
cover defined by a rim 5. The window 6 is transparent and is
located over the opening so that the display 4 can be seen through
it. The A cover and the B cover meet at a join 3.
[0003] The window 6 can be glued on to the A cover 1 by means of an
adhesive compound or a double-sided adhesive tape. Alternatively,
the window can be applied to the A cover as in-mould decoration
(IMD). FIG. 3 illustrates the use of in-mould decoration to apply
the window to the A cover. The window 10 is placed in a mould
cavity 11 in which the A cover is to be formed. (Step A). Then
plastics material to form the A cover is injected into the mould
cavity and allowed to set. (Step B). As it does so it adheres to
the window with the result that the finished A cover 12 can be
removed from the mould with the window 10 adhered to it. (Step
C).
[0004] Conventionally the A cover and the B cover are held together
by means of interior clips 9 as shown in FIG. 2. These allow the
housing to be assembled by locating the clips of the A and B covers
against each other and then pushing the covers into engagement.
[0005] Although it is easy to assemble, the housing construction
illustrated in FIGS. 1 and 2 has a number of disadvantages. First,
it can sometimes offer poor resistance to environmental
contaminants such as dirt or liquids, which can make their way into
the housing either at the join between the A cover and the B cover
or at the join between the A cover and the window. These
contaminants can cause the electronic components inside the housing
to malfunction. In that situation it is useful to be able to
disassemble the housing by disengaging the clips 9 so as to effect
a repair. Second, unless a large number of clips are
provided--which would increase the weight and cost of the
housing--the construction of FIGS. 1 and 2 can sometimes offer
little rigidity to the housing.
[0006] Instead of using clips, screws can be used to join the
covers to each other. These offer increased rigidity but they make
the housing more awkward to assemble.
[0007] The problems of contaminants entering the housing can be
addressed by using O-rings at the joins but this increases
cost.
[0008] There is therefore a need for an improved housing
construction.
[0009] According to one aspect of the present invention there is
provided a method for manufacturing an equipment housing,
comprising: locating together a first housing part and a second
housing part so that the first housing part overlaps the second
housing part at a join between the housing parts; and irradiating
the region of the join with radiation to which the first housing
part is substantially transparent and the second housing part is
absorptive so as to heat the second housing part and fuse the
housing parts together at the join.
[0010] According to another aspect of the present invention there
is provided an equipment housing comprising a first housing part
and a second housing part located so that the first housing part
overlaps the second housing part at a join between the housing
parts; and the parts being laser welded together at the join.
[0011] The first housing part is preferably located outward of the
second housing part at the join, most preferably over the entirety
of the join. By outward is meant outward with respect to the
housing, so that the first housing part preferably constitutes the
exterior surface of the housing at the join.
[0012] The first and second housing parts are preferably located in
contact with each other at the join.
[0013] The method may comprise irradiating the entire length of the
join. This preferably causes the parts to be fused together in a
continuous strip around the join. By this means the interior of the
housing may be sealed from the exterior. The housing preferably has
at least two electrical contacts embedded in it and exposed at the
outer surface of the housing, to allow electrical power to be
supplied to components within the housing. The power may serve to
charge a battery of the equipment within the housing.
Alternatively, contactless charging means such a magnetically
actuated charger could be provided in the housing.
[0014] The second housing part preferably includes a display
opening or another form of opening. The second housing part may
cover that opening, with the join conveniently surrounding the
opening.
[0015] One of the first and second housing parts is suitably a back
cover of the housing. The other of the housing parts is suitably a
front cover of the housing. Alternatively, one of the housing parts
could be a window of the housing, conveniently a transparent
display window and/or an IMD window.
[0016] The radiation is preferably laser light. The wavelength of
the laser light is preferably in the non-visible part of the
spectrum.
[0017] Preferably the irradiation step is performed so as to
generate insufficient heat to melt the outer surface of the first
housing part. By that means, the outer surface of the first housing
part, which preferably constitutes the outer surface of the housing
in the region of the join, is preferably unaffected by the
irradiation process.
[0018] The method preferably comprises the steps of: locating
together a third housing part and the second housing part so that
the third housing part overlaps the second housing part at a join
between the second and third housing parts; and irradiating the
region of the join between the second and third housing parts with
radiation to which the third housing part is substantially
transparent and the second housing part is absorptive so as to heat
the second housing part and fuse the second and third housing parts
together at the join.
[0019] The housing parts are preferably welded together at the join
by the radiation.
[0020] The housing parts are preferably made of plastics material.
The melting points of the housing parts are preferably below
250.degree. C., more preferably below 200.degree. C.
[0021] The housing could be a housing for a portable electronic
device, for example a mobile phone.
[0022] The step of locating together the first and second parts may
be formed by a process of in-mould decoration. The first part may
be moulded into the second part.
[0023] The present invention will now be described by way of
example with reference to the accompanying drawings, in which:
[0024] FIG. 1 shows a housing for a mobile phone;
[0025] FIG. 2 shows a cross-section on line A-A in FIG. 1;
[0026] FIG. 3 illustrates the application of a window to an A cover
by in-mould decoration;
[0027] FIG. 4 shows a cross-section through a housing for a mobile
phone;
[0028] FIG. 5 illustrates a laser welding process; and
[0029] FIG. 6 shows designs for housing part overlaps.
[0030] FIG. 4 shows a cross-section through a housing for a mobile
phone whose basic components are broadly similar to those of the
housing of FIGS. 1 and 2. In. FIG. 4 like components are numbered
as for FIGS. 1 and 2.
[0031] In the housing of FIG. 4 the join 14 at the periphery of the
window 6, between the window and the A cover, and the join 3
between the A cover and the B cover are laser welded. At each of
those joins a laser welding process has been used to melt at least
one of the components that meet at the join, to fuse those
components together. The fused zones are indicated at 15 in the
enlarged regions of FIG. 4 The laser welding runs around the
entirety of each of the joins. As a result, the interior of the
housing is sealed from the outside; this prevents contaminants from
entering the housing. Also, since the components are fused together
the housing is stronger than it would be if it was only clipped
together.
[0032] The process of putting IMD foil on to the window is
preferably done separately from the moulding of the A cover. To
achieve this the IMD foil is placed in the window mould, then
window material is injected into the mould and the IMD foil is
stuck to the window when it is cooled. This forms what can be
termed the IMD Window. The IMD window is then placed on the A
cover. Pressure is then applied to clamp the two parts together
before the laser welding.
[0033] FIG. 5 illustrates the laser welding process. Having been
clipped together, and with the window 6 in place on the A cover 1,
the housing is moved along a production line to a laser welding
station indicated generally at 21. The laser welding station has a
laser 22 on a robot arm 23. Once the housing has been located
relative to the arm against a jig 24 the laser is activated and the
arm 23 is moved along a pre-programmed path to scan the laser beam
over the joins that are to be welded. Where it hits the housing the
laser beam is absorbed, generating heat which locally melts one or
more of the housing components at that location and creating the
weld.
[0034] The laser is suitably a diode laser.
[0035] At each join where a weld is made it is preferred that one
of the two components that meet at the join overlaps the other, and
that the overlapping component (when viewed from outside the
housing) is relatively transparent to the laser beam but the
overlapped component is relatively absorptive to the laser beam.
For example, in the housing of FIG. 4 the window 6 overlaps the A
cover 1 at the join between them, and the window is preferably
transparent to the laser beam whereas the A cover is preferably
absorptive to it. The B cover 2 overlaps the A cover 1 at the join
3 between them, and the B cover is preferably transparent to the
laser beam whereas the A cover is preferably absorptive. With this
arrangement the centre of the zone at which melting occurs during
the laser welding process is spaced inward of the outer surface of
the housing. The laser beam is preferably scanned along the joins
slowly enough to cause local melting sufficient to form a weld but
quickly enough that the zone of melting does not spread to the
outer surface of the housing. This leaves the outer surface of the
housing intact after the laser welding process, so that the surface
finish of the housing is not marred by the laser welding.
[0036] A number of factors influence the effectiveness of the
welding process. One is the degree of light transmission through
the part to be welded. Another is the power of the laser beam that
is used. Normally low transmission can be compensated for by
increasing the laser power. Theoretically, as long the laser is
able to transmit through the material, it should be possible to
create a weld by adjusting the laser power to a sufficiently high
level. However, it should be noted that the quality of the weld
will be poorer if there is not enough laser power to heat up the
interface area adequately. The applicant has successfully
laser-welded a material having a transmission rate of 30% (material
C1000HF-16100 natural). However, in general more transmissive
materials are preferred.
[0037] The materials of the window, the A cover and the B cover are
selected to have the appropriate absorptive properties. By the use
of suitable pigments or dyes within the materials, the materials'
absorption in the visible range can be selected independently of
their absorption at the wavelength of the chosen laser. The laser
can also be selected to have a suitable emission wavelength.
Examples of materials that can be used for the transmissive
component (through which the laser is shone to the weld) and the
absorptive component are listed below:
1 Absorptive Transmissive PC/ABS C1000HF warm black PC/ABS C1000HF
natural PC/ABS C1000HF warm black PC Lexan HF 1110 clear PC/ABS
C1000HF warm black PMMA Oroglas M1-4T clear PC/ABS C1000HF warm
black PC IR grade makrolon 2405 PC Xantar J50/20/TF/15 PC/ABS
C1000HF natural ABS Terluran 949T PC IR grade makrolon 2405 PC
Lexan HF 1110 black PC IR grade makrolon 2405 PC Xantar
J50/20/TF/15 PC IR grade makrolon 2405 ABS Terluran 949T PC/ABS
C1000HF natural PC Lexan HF 1110 black PC/ABS C1000HF natural ABS
Terluran 949T PMMA Oroglas M1-4T clear PC Lexan HF 1110 black PMMA
Oroglas M1-4T clear PC Xantar J50/20/TF/15 PMMA Oroglas M1-4T clear
PC Lexan HF 1110 black PC Lexan HF 1110 clear ABS Terluran 949T PC
Lexan HF 1110 clear
[0038] Where a dye is used it should preferably not affect the
optical characteristic of the parts too much if possible.
[0039] Instead of the A cover being relatively absorptive it could
be relatively transparent and the other components relatively
absorptive to the laser beam.
[0040] The clips 9 could be omitted in the construction of FIG.
4.
[0041] The window 6 is preferably attached to the A cover 1 by an
in-mould decoration technique.
[0042] Optionally, only one of the welds could be made--for
example, the weld between the window 6 and the A cover 1 could be
omitted.
[0043] Other techniques such as ultrasonic welding could be used to
weld the parts of the housing together. However, laser welding has
been found to have a further advantage in that it does not affect
sensitive components within the housing.
[0044] FIG. 6 illustrates some examples of configurations for the
overlap between two housing parts A and B and the direction of a
laser on to the overlap to weld parts A and B together.
[0045] The technique described above could be used for the housings
of other articles than mobile phones, for instance calculators and
torches.
[0046] The applicant draws attention to the fact that the present
invention may include any feature or combination of features
disclosed herein either implicitly or explicitly or any
generalisation thereof, without limitation to the scope of any of
the present claims. In view of the foregoing description it will be
evident to a person skilled in the art that various modifications
may be made within the scope of the invention.
* * * * *