Information
-
Patent Grant
-
6385045
-
Patent Number
6,385,045
-
Date Filed
Friday, February 25, 200024 years ago
-
Date Issued
Tuesday, May 7, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
- Feild; Lynn D.
- Foster; David
Agents
-
CPC
-
US Classifications
Field of Search
US
- 361 704
- 361 705
- 361 627
- 361 628
- 361 631
- 361 647
- 200 23
- 200 511
- 200 3022
- 200 52 R
- 200 295
- 307 117
- 307 125
- 307 126
- 307 132 R
- 073 497
- 073 431
- 073 51432
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International Classifications
-
Abstract
A water-resistant switching device has an elastomeric body overmoulded to one part of the casing. The elastomeric body has a rib which co-operates with a hooked flange portion to define a space for receiving a hooked flange of another part of the casing to provide a watertight seal.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a water-resistant switching device and more particularly but not exclusively to an entry transmitter for a vehicle including such a switching device.
It is increasingly a requirement to provide electrical switching capable of being operated under damp conditions, for example in the open air when it is raining. In the case of entry transmitters for vehicles, which commonly use radio frequency or infra-red transmitters to operate entry systems for the corresponding vehicle, manufacturers are seeking increasing levels of waterproofing with current requirements ranging from 0.3 to 6 metres.
Prior art techniques to provide waterproofing in water-resistant switching devices include the use of an “O” ring seal, with pressure on the seal being maintained by, for example screws an overall elastomer keypad with the edge of the keypad crushed between two plastic elements and maintained there by clips, or by overmoulding the seal with elastomer.
These techniques have a number of defects, including the relatively high cost and difficulty of assembling when using screws and metal inserts, and the likelihood of plastic clips failing over long durations and high temperatures.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to at least partially mitigate the difficulties of the prior art.
According to a first aspect of the present invention there is provided a water-resistant switching device having a casing, the casing having first and second parts, said first part having a base wall and a peripheral edge wall, said device further comprising an elastomeric body extending along said base wall and forming an upstanding rib portion, wherein said rib portion is spaced from and co-operates with a portion disposed on the inside of side peripheral edge wall to receive a counterpart flange portion of the second part of said casing.
Preferably said counterpart flange portion has a thickness greater than said spacing, whereby when said counterpart flange portion of said second casing part is engaged with said portion, said rib portion resiliently grips said counterpart flange portion.
Conveniently said portion is part of said elastomeric body and forms an inwardly-directed flange portion from said peripheral edge wall, and said counterpart flange portion has an outwardly-directed lip for co-operation with said inwardly-directed flange portion.
Conveniently said portion is part of the peripheral edge wall and forms an inwardly-directed flange portion from said peripheral edge wall, and said counterpart flange portion has an outwardly-directed lip for co-operation with said inwardly-directed flange portion.
Conveniently said elastomeric body is secured to said first part of said casing.
Advantageously said elastomeric body is secured by overmoulding.
Conveniently said casing contains a circuit device, and said first part of said casing is an operating member for said circuit device.
Advantageously said casing contains a battery, and said first part of said casing is removable for changing said battery.
According to a second aspect of the present invention there is provided an entry transmitter for a vehicle comprising a water-resistant switching device according to the first aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will now be described with reference to the accompanying drawings, in which:
FIG. 1
shows a first vehicle entry transmitter of the prior art;
FIG. 2
shows a second vehicle entry transmitter of the prior art;
FIG. 3
shows a third vehicle entry transmitter of the prior art;
FIG. 4
shows a partial cross-section through a vehicle entry transmitter in accordance with a first embodiment of the present invention;
FIG. 5
shows a partial cross-section through the cap of the transmitter in
FIG. 4
, and
FIG. 6
shows a partial cross-section of another embodiment of the invention.
In the various figures like reference numerals indicate like parts.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to
FIG. 1
which shows a cross section through a portion of a first vehicle entry transmitter, a body portion
10
extends to define a cavity within which there is disposed a circuit element
11
.
A part
12
of rigid plastics is disposed to cover an opening
13
in the body
10
for access to replace battery
14
. An O ring
15
is disposed between two concentric upstanding portions
16
,
17
around the periphery of the opening
13
to afford waterproofing of the device. Screws
18
maintain an inward bias against the O ring so that waterproofing is maintained, and these are secured into threaded metal inserts
19
.
Although this arrangement can provide a good waterproofing performance, it is expensive to implement, because of the cost of the screws and metal inserts to secure the screws and secondly because of the labour costs involved in assembly.
Referring now to
FIG. 2
an elastomeric operating member
22
, has a button
28
projecting through a hole in the cap
23
. A lower portion
24
of the entry device body defines, in co-operation with the operating member
22
, a cavity within which the circuit member
11
is disposed. The lower portion
24
has an upstanding peripheral lip
25
. The cap
23
is retained in position against the lip
25
by the clipping action of a shaped flange portion
29
against the lip
25
. The elastomeric operating member
22
extends into a gap formed between a lower wall portion
26
of the cap and an upper wall portion
27
of the lower portion
24
. To aid retention of the elastomeric portion, either of the walls
26
or
27
can be provided with a barb portion
28
.
Referring now to
FIG. 3
, a third vehicle entry transmitter has a body formed of two parts
31
,
32
of which the lower
32
has an upstanding peripheral flange
33
with an inwardly-projecting lip portion
34
for clippingly engaging with a corresponding portion
35
of the upper part
31
to form a case. An elastomeric operating member
36
in the form of an elastomeric button protrudes through a hole of the upper part
31
and has a downward protrusion
37
for operating the circuit device
11
. The button
36
extends along the inner wall of the upper part
31
and is overmoulded to that wall to form a seal therewith. The lower part
32
of the case has a further upstanding rib
38
which, when the two parts are clipped together, is urged against an end face
39
of the elastomer to retain it in place.
Referring now to
FIG. 4
, the casing of a vehicle entry transmitter according to an embodiment of the invention comprises a lower part
41
and an upper part
42
. Both of these parts are made of hard plastics. The lower part
41
, has an upstanding flange portion
43
spaced from the peripheral edge of the part with an outwardly-directed lip portion
44
at the distal end thereof.
The upper part
42
, or first casing part, is a generally cup-shaped body having a generally planar base portion
45
and a peripheral side wall
46
. An elastomeric body
47
extends along the inner wall of the upper part
42
and has an upstanding rib portion
48
extending from the base wall
45
. A portion
50
disposed on the inside of the peripheral edge wall
46
is spaced from and co-operates with the rib portion
48
to receive the upstanding flange portion
43
of the lower part
41
, or second part of the casing. In this embodiment, the portion
50
is part of the elastomeric body
47
and is made of the same material. This elastomeric body
47
can also be used to form buttons through a hole in the upper part
42
(not shown in the figures).
The portion
50
of the elastomeric body extends in an end region thereof to an inwardly-directed flange
51
so that the outwardly-directed lip portion
44
can be clipped into engagement with the upper part
42
and retained there by engagement between the lip portion
44
and the flange portion
51
.
By comparison of FIG.
4
and
FIG. 5
, it will be seen that the spacing between the rib portion
48
and the portion
50
is less than the width of the flange portion
43
with its lip portion
44
, so that when the flange portion
43
of the lower part
41
is engaged with the portion
50
of the elastomeric body, the rib portion
48
resiliently grips the flange portion
43
.
Referring now to
FIG. 6
, it is shown another embodiment of the invention where the portion
50
is part of the peripheral edge wall
46
of the upper part
42
and is in the same material hard plastic. The elastomeric body
47
extends along the base wall
45
and presents an upstanding rib portion
48
. The other characteristics of this embodiment are the same as those describe in the context of
FIG. 4
: the portion
50
forms an inwardly-directed flange portion
51
from said peripheral edge wall
46
, and said counterpart flange portion
43
has an outwardly-directed lip
44
for co-operation with said inwardly-directed flange portion
51
.
The elastomeric body
47
is overmoulded onto the hard plastics upper part
42
for a secure holding.
The hard plastics material of the upper part
42
is nonetheless sufficiently flexible that pressure in the unsupported region of the base
45
causes it to distort inwardly to engage the circuit for operation thereof.
It is possible to unclip the upper part
42
to provide access to the battery
14
, for example to change the battery.
In an alternative embodiment the upper part
42
does not form an operating member, but is merely a casing part, removable for battery access.
The device of the invention is advantageous in that a simple clip-together assembly is afforded.
Although the invention has been described in the context of a vehicle entry transmitter, it is clear that other low voltage switching devices could use the same concept. Such devices include, for example, pagers and mobile phones and also external switching devices such as interphones and security locks.
Claims
- 1. A water-resistant switching device havinga casing, said casing having first and second parts, said first part having a base wall and a peripheral edge wall, said second part having a counterpart flange portion; and an elastomeric body extending along said base wall and forming an upstanding rib portion, wherein said peripheral edge wall, said base wall, and said rib portion cooperatively define a receiving portion, wherein said rib portion is spaced from and co-operates with said receiving portion disposed on the inside of said peripheral edge wall to receive said counterpart flange portion of said second part of said casing.
- 2. A water-resistant switching device according to claim 1 wherein said receiving portion is further defined by a projection of said elastomeric body.
- 3. A water-resistant switching device according to claim 1 wherein said receiving portion is further defined by a projection of said peripheral edge wall.
- 4. A water-resistant switching device according to claim 1 wherein said counterpart flange portion has a thickness greater than the spacing between said rib portion and the inside of said peripheral edge wall, whereby when said counterpart flange portion of said second part is engaged with said receiving portion, said rib portion resiliently grips said counterpart flange portion.
- 5. A water-resistant switching device according to claim 1 wherein said receiving portion is further defined by an inwardly-directed flange portion extending from said peripheral edge wall, and said counterpart flange portion has an outwardly-directed lip for co-operation with said inwardly-directed flange portion.
- 6. A water-resistant switching device according to claim 1 wherein said elastomeric body is secured to said first part of said casing.
- 7. A water-resistant switching device according to claim 6 wherein said elastomeric body is secured by overmoulding.
- 8. A water-resistant switching device according to claim 1 further including a circuit device, wherein said casing contains said circuit device, and wherein said first part of said casing is an operating member for said circuit device.
- 9. A water-resistant switching device according to claim 1 further including a battery, wherein said casing contains said battery, and wherein said first part of said casing is removable for changing said battery.
- 10. An entry transmitter for a vehicle comprising a water-resistant switching device according to claim 1.
- 11. A water-resistant switching device comprising:a casing having a first part including a base wall, an elastomeric body extending along the base wall and having a rib inwardly directed from the base wall, a peripheral edge wall extending from the base wall, and a first flange inwardly directed from the peripheral edge wall, the first flange and the rib defining a receiving portion; and a second part including a second flange, the second flange shaped to be positioned in and co-operate with the receiving portion.
- 12. The water-resistant switching device of claim 11 whereinthe elastomeric body further extends along the peripheral edge wall, and the first flange is an extension of the elastomeric body.
- 13. The water-resistant switching device of claim 11 whereinthe first flange is an extension of the peripheral edge wall.
- 14. The water-resistant switching device of claim 11 wherein the width of the receiving portion is defined by spacing between the rib and the peripheral edge wall, the second flange having a thickness greater than a portion of the spacing, the second flange engaged in the receiving portion, the rib resiliently gripping the second flange.
- 15. The water-resistant switching device of claim 11 wherein the second flange has a lip outwardly-directed to the peripheral edge wall, the lip operative to cooperatively engage the first flange.
- 16. The water-resistant switching device of claim 11 wherein the elastomeric body is secured to the base wall of the first part of the casing.
- 17. The water-resistant switching device of claim 11 wherein the elastomeric body is overmoulded by the base wall of the first part of the casing.
- 18. The water-resistant switching device of claim 11 further including:a circuit device disposed within the casing, wherein the first part of the casing is an operating member for the circuit device.
- 19. The water-resistant switching device of claim 11 further including:a battery disposed within the casing, wherein the first part of the casing is removable.
- 20. An entry transmitter for a vehicle including the water-resistant switching device according to claim 11.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9905725 |
Feb 1999 |
GB |
|
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
9309553 |
May 1993 |
WO |