Information
-
Patent Grant
-
6608273
-
Patent Number
6,608,273
-
Date Filed
Wednesday, July 17, 200222 years ago
-
Date Issued
Tuesday, August 19, 200321 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 200 5 A
- 200 5 R
- 200 283
- 200 284
- 200 406
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International Classifications
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Abstract
A thin push switch used in a portable electronic apparatus includes a less number of components jointed together without any adhesive controlled hardly, and can thus be favored with mass production. The push switch includes an insulating spacer having first cramp-locked tabs cramp-locked with the first terminals of a fixed plate and second cramp-locked tabs cramp-locked with the second terminals of a contact plate. The fixed plate includes a fixed contact, and the contact plate includes a movable contact. Accordingly, the contact plate, the insulating spacer, and the fixed plate can be joined together without an adhesive.
Description
TECHNICAL FIELD
The present invention relates to a thin push switch used in a portable electronic device such as a mobile telephone or a portable headphone stereo player.
BACKGROUND ART
As portable electronic apparatuses have been having a reduced size or thickness, downsizing of push switches in the device is significantly desired. A conventional push switch having a reduced size or thickness for optimum downsizing is disclosed in Japanese Patent Laid-open No.7-254327, and will be explained below referring to the relevant drawings.
FIGS. 8 and 9
are a perspective view and an exploded perspective view of the conventional push switch, respectively. A bottom metal plate
1
of the push switch has a fixed contact
2
provided on the center thereof, and also has first external terminals
1
A formed on one edge thereof which are downwardly bent in an L-shape. The metal plate
1
has notches
1
B formed at the opposite edge thereof having a specific width. An adhesive insulating sheet
3
having both surfaces thereof coated with an adhesive agent is bonded at the lower side with the adhesive agent to the upper side of the bottom metal plate l. The adhesive insulating sheet
3
has a center opening
3
A formed therein. Upon being bonded to the bottom metal plate
1
, the bottom metal plate
1
has a center contact
2
positioned a center of the center opening
3
A, and has an upper end of the center contact exposed upward through the center opening
3
A. The adhesive insulating sheet
3
includes notches
3
B formed corresponding to the notches
1
B formed at the other edge of the bottom metal plate
1
. The adhesive insulating sheet
3
is bonded with an elastic metal plate
4
at the upper side thereof with the adhesive agent. The elastic metal plate
4
includes a dome-shaped projection
5
swelling upward at the center of the plate
4
. The lower side of the projection
5
is positioned opposite to and spaced from the fixed contact
2
at the center of the plate
1
. The elastic metal plate
4
has second external terminals
4
A formed with bent downward in an L-shape. The second external terminals
4
A extend downward through the notches
3
B of the adhesive insulating sheet
3
and the notches
1
B of the bottom metal plate
1
with being electrically isolated from the bottom metal plate
1
.
An operation of the conventional push switch will be explained. Upon being depressed downward with a pressure, the dome-shaped projection
5
of the elastic metal plate
4
has the dome shape inverted with a click feel, and has the lower side directly contacts with the fixed contact
2
of the bottom metal plate
1
. This allows the elastic metal plate
4
and the bottom metal plate
1
to electrically conducts to each other, thus turning on the switch, i.e. the first external terminals
1
A and the second external terminals
4
A conducts to each other. Upon being released from the pressure, the dome-shaped projection
5
can return back to the original shape by an own elasticity, thus electrically disconnecting between the bottom metal plate
1
and the elastic metal plate
4
and turning off the switch.
The conventional push switch includes the bottom metal plate
1
and the elastic metal plate
4
bonded to each other with the adhesive agent of the adhesive insulating sheet
3
. It is however difficult to control and maintain the thickness and adhesivity of the adhesive agent coated on both sides of the adhesive insulating sheet
3
, and hence, extra steps for adjustment in the production of the switch is required.
DISCLOSURE OF THE INVENTION
A thin push switch includes a less number of components joined together without adhesive, causing a trouble, in the handling, and can thus be favored with mass production.
The push switch includes the following elements:
(A) A fixed plate including a fixed contact at the center thereof, first cramp-locking sections respectively provided at a pair of first ends opposite to each other, and a first terminal electrically connected with the fixed plate;
(B) A contact plate, which faces the fixed plate, including a movable contact facing the fixed contact, second cramp-locking sections respectively provided at a pair of second ends opposite to each other which are disposed at different positions from the first opposite ends of the fixed plate, and second terminals electrically connected with the movable contact; and
(C) An insulating spacer, which is disposed between the fixed plate and the contact plate, including first cramp-locked tabs being positioned corresponding to the first ends and cramp-locked by the first cramp-locking sections, second cramp-locked tabs being positioned corresponding to the second ends and cramp-locked by the second cramp-locking sections, and an opening facing the fixed contact.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a side cross sectional view of a push switch according to an exemplary embodiment of the present invention.
FIG. 2
is a perspective view of the push switch according to the embodiment.
FIG. 3
is an exploded perspective view of the push switch being not assembled according to the embodiment.
FIG. 4
is a partially enlarged cross sectional view of a fixed contact and a movable contact of the push switch in its operation according to the embodiment.
FIG. 5
is a perspective view of a fixed plate having a knurl of the push switch of the embodiment.
FIG. 6
is a back view of a fixed plate having a recess of the push switch according to the embodiment.
FIG. 7
is a perspective view of the push switch including a contact plate having a movable contact according to the embodiment.
FIG. 8
is a perspective view of a conventional push switch.
FIG. 9
is an exploded perspective view of the conventional push switch.
BEST MODES FOR CARRYING OUT THE INVENTION
FIG. 1
is a cross sectional side view of a push switch according to an exemplary embodiment of the present invention.
FIG. 2
is a perspective view of the assembled push switch.
FIG. 3
is an exploded perspective view of the push switch which is not assembled.
A fixed plate
11
made of a metal has a fixed contact
12
projecting upward provided at the center of a bottom portion
11
A substantially shaped in square. The fixed plate
11
includes a pair of first terminals
13
extending outward from two opposite edges of the bottom portion
11
A. As shown in
FIG. 3
, each first terminal
13
is arranged in a squared U-shape upwardly opening. The terminal
13
includes a first extension
13
A of a specific width being formed unitarily with the bottom portion
11
A and extending horizontally from the edge of the bottom portion
11
A, and a couple of first cramp-locking tabs
13
B bent upward from both sides of the first extension
13
A.
An insulating spacer
14
is provided to overlap the fixed plate
11
. The spacer is made of heat-resistant insulating resin material and shaped substantially in square which is equal to or slightly greater than the size of the bottom portion
11
A. As both are overlapped, the fixed contact
12
is exposed through an opening
14
A provided at the center of the insulating spacer
14
. The insulating spacer
14
includes first cramp-locked tabs
14
B respectively extending horizontally from two opposite ends of the square shape about the opening
14
A. The width of the first cramp-locked tab
14
B is substantially equal to or slightly smaller than that of the first extension
13
A of the first terminal
13
. The length of the first cramp-locked tab
14
B is slightly greater than that of the first extension
13
A. The insulating spacer
14
has second cramp-locked tabs
14
C respectively extending horizontally from two other opposite ends of the square shape about the opening
14
A. The line extending across the first cramp-locked tabs
14
B is designated at substantially a right angle to the line extending across the second cramp-locked tabs
14
C. The insulating spacer
14
is jointed to the fixed plate
11
through having the first cramp-locked tabs
14
B put on the first sections
13
and cramp-locked by the first cramp-locking tabs
13
B of the fixed plate
11
.
A contact plate
15
made of an elastic metal plate includes a top portion
15
A sized generally identical to the bottom portion
11
A of the fixed plate
11
. The contact plate
15
includes a pair of second terminals
16
respectively extending outward from two opposite edges of the top portion
15
A. More specifically, the contact plate
15
is placed over the insulating spacer
16
, so that the line extending across the second terminals
16
may intersect substantially at a right angle to the line extending across the first terminals
13
. As shown in
FIG. 3
, each second terminal
16
is arranged a squared U-shape opening downward. The terminal
16
includes a second tab
16
A of a specific width extending horizontally from the edge of the top portion
15
A and a couple of second cramp-locking tabs
16
B bent downward from both sides of the second tab
15
A. The width of the second cramp-locked tab
14
C is generally equal to or slightly smaller than that of the second tab
16
A of the second terminal
16
. The length of the second cramp-locked tab
14
C is slightly greater than that of the second tab
16
A. The insulating spacer
14
is jointed to the contact plate
15
through having the second cramp-locked tabs
14
C, which are not cramp-locked with the first terminals
13
, put directly from below the second terminals
16
and cramp-locked by the second cramp-locking tabs
16
B of the contact plate
15
.
While the fixed plate
11
, the insulating spacer
14
, and the contact plate
15
are jointed together to be a single assembly, a portion of the contact plate
15
corresponding to the opening
14
A of the insulating spacer
14
, i.e., a center of the top portion
15
A opposite to the fixed contact
12
of the fixed plate
11
operates as a movable contact
17
of the push switch.
An operation of the push switch according to the embodiment will be described below.
While the movable contact
17
of the contact plate
15
is not depressed, as shown in
FIG. 1
, the lower side of the contact
17
is spaced from the fixed contact
12
by the insulating spacer
14
, hence leaving the push switch turned off.
When the movable contact
17
or the center of the top portion
15
A of the contact plate
15
is pressed down as denoted by an arrow mark of FIG.
1
and deflected downward with elastic deformation, the lower side of the contact
17
directly contacts with the fixed contact
12
.
FIG. 4
illustrates the movable contact
17
pressed down and held directly contacting with the fixed contact
12
. As a result, the push switch is turned on with the first terminal
13
conducted to the second terminal
16
.
Then, when the depressing action is canceled, the contact plate
15
returns back to the original position with an elasticity of the plate
15
as shown in FIG.
1
. As the movable contact
17
has been isolated from the fixed contact
12
, the push switch is turned off.
The push switch according to the embodiment has the insulating spacer
14
jointed by cramp-locking to the fixed plate
11
and the contact plate
15
. This requires no adhesive agent which may be cause trouble during being handled and a less number of steps for checking the cramp-locked portions.
In addition, the process of assembling the push switch includes aligning the fixed plate
11
and the contact plate
15
together with reference to the insulating spacer
14
and joining them together by simply cramp-locking, thus enabling the switch to be mass-manufactured continuously easily.
As shown in
FIG. 5
, the fixed plate
11
may includes the fixed contact
21
having a knurl at the top thereof for increasing the number of contact points and for improving steadiness of contact between the fixed contact
21
and the lower side of the movable contact
17
of the contact plate
15
. The knurl prevents the fixed contact
21
from any tiny particles of dust in a recess and prevents the switch from being stuffed between the contacts, thus contributing to an highly steady, reliable operation of the push switch.
Alternatively, the fixed plate
11
may include a pattern of grooves
13
C surrounding the first terminals. The grooves
13
C are provided on the lower side, on which the switch is mounted to a printed circuit board (PCB). The grooves
13
C allows the push switch to have an enhanced operational steadiness and reliability as receiving a flux for the process of mounting the push switch to the PCB.
Even if the flux moves into a space between the fixed plate
11
and insulating spacer
14
or between the contact plate
15
and insulating spacer
14
, the flux can stop at the edge of the opening
14
A provided in the insulating spacer
14
by a surface tension of the flux.
Once the flux is cured between the fixed plate
11
and insulating spacer
14
or between the contact plate
15
and insulating spacer
14
, the flux securely bonds the plates thus increasing the joining strength between the plates during the mounting process.
The contact plate
15
may be covered at the upper side thereof with an insulating film when the push switch is installed at a specific location where a static electricity is inevitable. The insulating film protects the push switch from the static electricity, thus increasing the operational reliability of the switch.
FIG. 7
is a perspective view of a modification of the push switch. The switch includes a contact plate
31
including a movable contact
32
formed in a dome-shape expanding upward provided at the center of the contact
32
. The movable contact
32
is inverted in the shape by a pressing operation. Therefore, the switch may be turned on with a click feel.
Also, as shown in
FIG. 7
, the dome-shaped movable contact
32
may be surrounded by slits
33
. This reduces the joints between the movable region and the non-movable region. Accordingly, the contact plate
31
can be prevented from a load applied to the inverted movable contact
32
in the shape. This allows an operator to feel the click more clearly. The slit
33
may be replaced by an aperture with the same effect.
Moreover, upon including the slits or apertures, the contact plate
31
may be accompanied with an insulating film
34
applied over the upper side of the plate
31
for reducing an influence of a static electricity. This prevents any matter from entering and fouling the contact of the switch, thus avoiding malfunction of the switch.
The fixed plate, the contact plate, and the insulating spacer of the push switch are not limited to a square shape but may be arranged of any appropriate shape such as a round shape.
The switch above-described includes the first cramp-locking sections operating as the first tab of the fixed plate and the second cramp-locking sections operating as the second tab of the contact plate. They may be arranged separately. More specifically, the fixed plate may include first terminals and first cramp-locking sections provided separately at two opposite ends the plate, respectively. Similarly, the contact plate may include second terminals and second cramp-locking sections provided separately at two opposite ends the plate, respectively.
INDUSTRIAL APPLICABILITY
As set forth above, a thin push switch according to the present invention has a reduced number of components joined to each other by simply cramp-locking. The push switch, since being efficiently assembled by an unelaborate step of cramp-locking, can be favored with mass production. The push switch thus has an improved performance and reduced in the cost.
Claims
- 1. A push switch comprising:a fixed plate including: a fixed contact provided at a center thereof; first cramp-locking sections provided at a pair of first ends opposite to each other thereof; and a first terminal electrically connected with said fixed plate; a contact plate facing said fixed plate, including: a movable contact provided at a location facing said fixed contact; second cramp-locking sections provided at a pair of second ends opposite to each other thereof, said second ends being at different positions from said first ends; and a second terminal electrically connected with said movable contact; and an insulating spacer disposed between said fixed plate and contact plate, said insulating spacer having an opening formed at a position facing said fixed contact, said insulating spacer including: first cramp-locked tabs located at said first ends and cramp-locked by said first cramp-locking sections; and second cramp-locked tabs located at said second ends and cramp-locked by said second cramp-locking sections.
- 2. A push switch according to claim 1, wherein said first terminal is provided unitarily with said first cramp-locking sections.
- 3. A push switch according to claim 1, wherein said second terminal is provided unitarily with said second cramp-locking sections.
- 4. A push switch according to claim 1, wherein said fixed contact includes a knurl provided on a first side thereof facing said movable contact.
- 5. A push switch according to claim 1, wherein said fixed plate having a recess formed on a second side thereof near said first terminal, said second side being opposite to said first side.
- 6. A push switch according to claim 1, wherein said movable contact includes a dome-shaped portion projecting towards a direction opposite to a direction to said fixed plate.
- 7. A push switch according to claim 6, wherein at least one of a slit and an aperture is formed around said dome-shaped portion.
- 8. A push switch according to claim 1, further comprising an insulating film provided on said contact plate at an opposite side to a side facing said fixed plate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-250646 |
Aug 2000 |
JP |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/JP01/06773 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO02/17340 |
2/28/2002 |
WO |
A |
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
60-57025 |
Apr 1985 |
JP |
02-106642 |
Aug 1990 |
JP |
07-254327 |
Oct 1995 |
JP |
11-265634 |
Sep 1999 |
JP |