Information
-
Patent Grant
-
6489580
-
Patent Number
6,489,580
-
Date Filed
Wednesday, January 24, 200123 years ago
-
Date Issued
Tuesday, December 3, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Wenderoth, Lind & Ponack, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 200 406
- 200 292
- 200 622
- 200 832
-
International Classifications
-
Abstract
A push-on switch includes an insulating resin case 21 which contains a main body 24, a central fixed contact point 22 and an outer fixed contact point 23 fixed on the back wall of a front-open recess 21A; a domed movable contact 27; and an operating body 29 supported by a cover 30. The case 21 has an overhang 25, which stretches horizontally from the case in the upper part to be of a size greater than the size of main body 24. The overhang 25 is provided with terminals 26 electrically coupled with the central fixed contact point 22 and the outer fixed contact point 23, respectively. In the above-configured switch, the constituent parts are simplyformed, and can be manufactured through easy mold machining or other processing methods.
Description
FIELD OF THE INVENTION
The present invention relates to a side-push type push-on switch for use in operating sections of various kinds of electronic apparatus. A method for mounting the switch is also included.
BACKGROUND OF THE INVENTION
There is an increasing need for inexpensive push-on switches that can be operated with a sidewise push force, or an operating force exerted in a direction parallel to the surface plane of a printed circuit board. Also, in view of the prevailing trends for downsized equipment and the preference for slim-shaped designs in the market of electronic apparatus, switches for such apparatus are requested to be small enough to satisfy various designing requirements.
A side-push type push-on switch known to meet the above-described general requirements is disclosed in Japanese Utility Model Laid-open Publication No. 51126.
FIG. 15
shows a cross-sectional side view of a conventional push-on switch, and
FIG. 16
is an exploded perspective view. As shown in
FIG. 16
, a resin case
1
that opens upward is provided in its inner recess with a pair of outer fixed contact points
2
and a central fixed contact point
3
formed integrally by insert molding. The respective fixed contact points
2
and
3
are electrically coupled with terminals
4
provided on an outside wall surface of the resin case
1
.
A rectangular movable contact
5
made of an elastic thin metal sheet is formed of a frame
5
A and a bridging arch
5
B disposed in the middle of the frame
5
A. The movable contact
5
is placed so that the frame
5
A makes contact with the outer fixed contact points
2
.
The bridging arch
5
B of movable contact
5
is held above the central fixed contact point
3
with a certain specific clearance.
Placed further above are a flexible anti-dust sheet
6
made of an insulating resin and an operating member
7
.
The operating member
7
consists of an operating section
8
protruding toward the front from an opening
1
A of side wall of case
1
, and a flat plate section
9
formed integrally behind the operating section
8
. The flat plate section
9
is provided in the middle part with a C-shaped vacancy
10
(“C-shaped” includes a square shape without one side), with its opening facing the front; the remaining central portion has a thinned area
12
at a stem region so that the central portion functions as a pushing section
11
, which pushes the contacts.
The operating member
7
is placed, at the flat plate section
9
, on a step existing around the recess of case
1
so that the pushing section
11
is located above the bridging arch
5
B of movable contact
5
.
A press board
13
is attached on the case
1
covering the flat plate section
9
of operating member
7
, with claws
13
A hooked to recesses
1
B provided on the outer wall.
Thus the flat plate section
9
is supported between the step existing around the recess of case
1
and the bottom surface of the press board
13
, and the operating member
7
can slide to-and-fro.
In the press board
13
, an “L”-shaped bracket
15
is formed downward between a pair of slits
14
. The steep-angled front face of bracket
15
contacts with the tip end
11
A of the pushing section
11
of the operating member
7
.
The above-configured conventional push-on switch is, in a normal mounting method, put on a printed circuit board and soldered, at its external connection terminals
4
, with a circuit pattern (not shown) formed on the printed circuit board (not shown) of an apparatus, with the operating section
8
protruded from the front edge.
As to the operating mechanism of the conventional push-on switch, when the operating section
8
of operating member
7
protruding from the front edge of the printed circuit board is pressed towards a direction as indicated by an arrow in
FIG. 15
, the flat plate section
9
, which is an integral part of the operating section
8
, moves together along a space formed by parallel surfaces of the case
1
and the press board
13
. The pushing section
11
moves in the same direction as well.
Since the pushing section
11
is in contact, at the tip end
11
A, with the steep-angled front face of the bracket
15
of press board
13
, the whole pushing section
11
bends downward with the thinned area
12
formed at the stem as the fulcrum. The bottom surface of tip end
11
A of pushing section
11
pushes the bridging arch
5
B of movable contact
5
down via the anti-dust sheet
6
, and then the bridging arch
5
B is reversed to mechanically contact, at its bottom surface, with the central fixed contact point
3
. The outer fixed contact points
2
and the central fixed contact point
3
are made to have an electrical contact via the movable contact
5
; or, the switch is brought to ON state.
When the pressure on the operating section
8
is withdrawn, the pushing section
11
is pushed back to its upper position by an elastic restorative force of the bridging arch
5
B of movable contact
5
, and slides along the bracket
15
to return to the original position; thus, the switch returns to the OFF state as shown in FIG.
15
.
In the above-configured conventional push-on switch, the pushing section
11
needs to be provided in the operating member
7
; therefore, a C-shaped vacancy
10
has to be formed in the flat plate section
9
and a thinned area
12
must be created at the stem. In order to meet the stricter requirements for downsizing, it is desired for the length of the pushing section
11
of operating member
7
to be shorter, the thickness of the thinned area
12
is to be reduced a step further, and also the size of the movable contact
5
is to be still smaller. This means that it is necessary to make more precise machining for the dies and molds, and to provide more severe controls over, for example, the flow characteristics of resin materials, the conditions for operating the molding machines, as well as the maintenance of precision dies and molds and other items. This inevitably results in a higher cost.
Conventionally, the mounted switches are fixed only by soldering the terminals
4
on a printed circuit board. Therefore, the conventional switches are vulnerable to operating forces exerted in parallel with the printed circuit board. Enhancement of the mounting strength has been an outstanding item that needs improvement with the conventional push-on switches.
The present invention addresses the above tasks for improvement, and aims to provide a compact side-push type push-on switch. Die and mold machining and preparation of constituent parts for the push-on switch of the present invention are easier and lower in total cost. In the push-on switches of the present invention, operating forces exerted onto the switch are encountered by the end-face at the edge of a printed circuit board.
SUMMARY OF THE INVENTION
A switch of the present invention comprises:
an insulating resin case containing a main body of a switch mechanism formed in a front-open cavity, where a central fixed contact point and an outer fixed contact point are fixed on the inner surface of a recess;
a domed movable contact housed in the recess, the movable contact constituting the switching contact element coupled with the fixed contact points; and
an operating body supported by a cover so that it can move to-and-fro for pushing at the rear end the domed movable contact.
The resin case is provided with an overhang which stretches (extends) horizontally from the case in the upper part of a region corresponding to the main body of the switch mechanism for a distance greater than the size of main body region. The overhang is provided with terminals, electrically coupled with the central fixed contact point and the outer fixed contact point, respectively.
Thus, a complex mechanism conventionally needed for converting a sidewise operating force into a switching action is replaced by a simple structure. Namely, in a side-push type push-on switch of the present invention, the domed movable contact is pushed directly by the rear end of an operating body which can move to-and-fro in the direction of the operating force.
The constituent components of the above-configured push-on switch are of simple construction, so they can be prepared through simple and easy procedures of mold machining and/or other manufacturing processes at low cost. In addition, the push-on switch operates with a superior functional feeling.
Furthermore, the push-on switch of the present invention is mounted on a printed circuit board with the back wall of the case, in the main body region, making contact with the end-face of a cut provided in a printed circuit board while a bottom of the overhang is immediately contact on to the upper surface of the printed circuit board, and the terminals provided in the overhang are connected with respective circuit patterns on the printed circuit board. Therefore, the operating force applied to the operating body is ultimately encountered by the end-face of the printed circuit board in an area behind the main body. Thus high connection reliability is ensured in the present push-on switches with respect to the printed circuit board.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a cross-sectional view of a push-on switch in a first exemplary embodiment of the present invention.
FIG. 2
is a perspective view of the push-on switch, as a finished product.
FIG. 3
is an exploded perspective view of the push-on switch.
FIG. 4
is a cross-sectional view of the push-on switch, in a state of being pushed.
FIG. 5A
is a perspective view showing a method for mounting the push-on switch.
FIG. 5B
is a perspective view showing another method for mounting the push-on switch.
FIG. 6
is a perspective view in part of an electronic apparatus, showing a state where the push-on switch is mounted on a printed circuit board.
FIG. 7A
is a cross-sectional view showing a state where the push-on switch is put on a printed circuit board with a slight dislocation.
FIG. 7B
is a cross-sectional view showing a state after the push-on switch is mounted and soldered on a printed circuit board.
FIG. 8
is a cross-sectional view of a push-on switch in a second exemplary embodiment of the present invention.
FIG. 9
is a cross-sectional view of the push-on switch in a state of being pushed.
FIG. 10
is a perspective view of a push-on switch in a third exemplary embodiment of the present invention.
FIG. 11
is an exploded perspective view of the push-on switch.
FIG. 12
is a perspective view in part of an electronic apparatus, showing how a push-on switch in a fourth exemplary embodiment is mounted thereon.
FIG. 13
is a perspective view in part of an electronic apparatus, showing a state after a push-on switch in a fifth exemplary embodiment is mounted on the printed circuit board.
FIG. 14
is a perspective view of another example, showing a state after mounting.
FIG. 15
is a cross-sectional view of a conventional push-on switch.
FIG. 16
is an exploded perspective view of the conventional push-on switch.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention are described in the following with reference to the drawings.
First Embodiment
FIG. 1
shows a cross-sectional side view of a push-on switch in accordance with a first exemplary embodiment of the present invention;
FIG. 2
shows a perspective view; and
FIG. 3
is an exploded perspective view.
As shown in the
FIGS. 1-3
, a case
21
made of an insulating resin contains a main body
24
of a switch mechanism formed in a front-open recess
21
A, where a central fixed contact point
22
and two outer fixed contact points
23
disposed symmetrically at both sides of the central fixed contact point
22
are provided integrally by an insert molding method in the inner back wall of the recess so that these fixed contact points are exposed to approximately the same height from the wall surface.
The resin case
21
is provided with an overhang
25
which stretches (extends) horizontally in the directions towards both sides and towards the rear from the resin case
21
in the upper part of the main body
24
of the switch mechanism so as to have a size greater than the size of the main body.
The overhang
25
is provided in the rear comers at the right and the left with connection terminals
26
, which are electrically coupled respectively with the central fixed contact point
22
and the outer fixed contact points
23
. Each of the connection terminals
26
consists of a parallel part
26
A which extends along the side and rear walls of overhang
25
and a protrusion part
26
B which stretches sidewise from the parallel part
26
A at the same level as the bottom surface of the overhang
25
.
Although the connection terminal
26
is compatible with the reflow soldering by the parallel part
26
A alone, the extrusion part
26
B contributes to an increase in the connection stability after soldering.
A round domed movable contact
27
made of an elastic metal sheet is housed in the recess
21
A of case
21
with the circumferential edge placed on the outer fixed contact points
23
, so that it opposes the central fixed contact point
22
with a certain predetermined clearance between the contact point
22
and a rear surface of a dome summit
27
A of contact
27
.
In the front of the domed movable contact
27
, a flexible insulating sheet
28
is provided for sealing the recess
21
A of case
21
closed against dust and supporting the domed movable contact
27
.
The insulating sheet
28
not only determines the location of the domed movable contact
27
itself, but it regulates a relative positioning of movable contact
27
with the fixed contact points
22
and
23
.
The insulating sheet
28
may be provided with a pressure sensitive adhesive layer or a sticking agent layer on its surface. These layers further increase a positional accuracy of the movable contact
27
against the fixed contact points
22
and
23
and assure the long-term contact reliability.
An operating body
29
is provided in front of the domed movable contact
27
, via the insulating sheet
28
. The operating body
29
can move to-and-fro to push at its rear end pushing part
29
A the domed movable contact
27
at the dome summit
27
A.
A flange
29
B of the operating body
29
can slide to-and-fro while being guided by a wall
21
B protruding forward from the case
21
, so the operating body
29
can move together. An operating part
29
C provided in the front of flange
29
B protrudes through an opening
30
A of a cover
30
attached to the case
21
.
The cover
30
is attached and fixed to the case
21
, as shown in
FIG. 2
, by hooking claws
30
B in trenches
21
C provided in the case
21
at the right and left.
The cover
30
may be attached and fixed to the case
21
also by other means; for example, providing a dowel (not shown) at the front of case
21
and hammering it flat after it penetrates through a hole provided in the cover
30
.
Now in the following, operation of the above-configured push-on switch in the present embodiment is described.
FIG. 1
shows the push-on switch in an OFF state. When the operating body
29
is pressed at operating part
29
C in a direction as indicated by an arrow, the operating part
29
C moves straight, without any dislocation or tilting, in the direction of the arrow, guided at the flange
29
B by the inner surface of wall part
21
B of case
21
. Pushing part
29
A of the operating body
29
pushes, via insulating sheet
28
, the domed movable contact
27
at the dome summit
27
A.
When the strength of the pressing force goes beyond a certain level, the domed movable contact
27
reverses, which is accompanied a click feeling, to contact with the central fixed contact point
22
at the rear surface at dome summit
27
A. Thus the central fixed contact point
22
and the outer fixed contact points
23
are brought into electrical conduction via the domed movable contact
27
. The two terminals
26
provided in the overhang
25
are brought into electrical contact accordingly. Now the push-on switch is ON, as shown in FIG.
4
.
The domed movable contact
27
is regulated in the position by the insulating sheet
28
and kept in a certain predetermined position during the pressing operation; therefore,
1) a clear click-feeling is generated every time when it is pushed with a certain force, providing a stable electrical contact between the central fixed contact point
22
and the outer fixed contact points
23
, and
2) the operational action of pushing proceeds smoothly, since there is no slide resistance between the pushing part
29
A of operating body
29
and the upper surface of domed movable contact
27
.
When the pressure exerted on the operating body
29
is withdrawn, the domed movable contact
27
restores its original shape with a self restorative elastic force, and returns the operating body
29
to the initial location, bringing the switch to its OFF state as shown in FIG.
1
.
At this state, since the front surface of flange
29
B is in contact with the rear surface of cover
30
, the operating body
29
rests at a certain predetermined position.
As described above, in a push-on switch in the present embodiment, when an operating force is applied to the operating part
29
C, the operating body
29
moves in the same direction in which the operating force is applied and the pushing part
29
A, which is the rearmost part of the operating body
29
, pushes the domed movable contact
27
directly. Thus the push-on switch has a simple structure, using simple constituent components. They can be manufactured through an easy mold machining or other machining processes at low cost. The above-configured side-push type push-on switch provides also a superior feeling of operation.
Next, a method for mounting a push-on switch in the present embodiment, as well as an electronic apparatus containing the push-on switch, are described.
FIGS. 5A and 5B
show methods for mounting a push-on switch in the present exemplary embodiment onto a printed circuit board. There are two methods for mounting, as shown respectively in FIG.
5
A and FIG.
5
B.
A first method for mounting is shown in
FIG. 5A. A
rectangular cut
32
slightly larger than the size of case
21
in the region of main body
24
is provided in the front end of printed circuit board
31
. The cut
32
has a width slightly greater than a width of the main body
24
, and a depth substantially identical to a depth of the main body
24
including the thickness of cover
30
. Two lands
34
are provided on the printed circuit board
31
so that they respectively surround the cut comers, and the lands
34
are each connected with a circuit pattern
33
formed on the printed circuit board
31
.
A push-on switch is held at the overhang
25
provided in the upper part of case
21
to be positioned so that the region of main body
24
is just above the cut
32
of printed circuit board
31
.
And then, it is lowered as indicated by an arrow to have the region of main body
24
inserted in the cut
32
, until the bottom surface of overhang
25
comes in contact with the upper surface of printed circuit board
31
. Then, as shown in
FIG. 6
, the terminal
26
provided in the overhang
25
is positioned on the land
34
of printed circuit board
31
, and the back wall surface of case
21
in the region of main body
24
is in contact against the end-face of the cut
32
.
Finally, after the terminal
26
is connected to the land
34
, an electronic apparatus is completed with the operating part
29
C protruded from the front edge of printed circuit board
31
.
Since the terminal
26
is provided with the extrusion part
26
B, a push-on switch mounted on printed circuit board
31
can be soldered with a broader space to have a high connection strength, even when it is soldered by reflow soldering. Thus a rigid and stable connection can be produced through a reduced number of process steps.
It is preferred to provide the land
34
on printed circuit board
31
with a slight space from the corner of the cut
32
. Forming the land
34
in the above-described pattern arrangement will prevent cream solder, etc. from oozing out into the space of the cut
32
. This contributes to providing a stable mounting quality.
The cut
32
may be tapered narrower towards its lower part, with the case
21
also provided with the corresponding taper in the region of main body
24
. The above-described arrangement eases mounting operation of a push-on switch on a printed circuit board; namely, even if the starting position of a push-on switch is slightly dislocated, it will proceed along the tapered slope of the end-face, eventually reaching to an exact position.
It is preferred to make the width of the cut
32
, where rectangular cut
32
and side surfaces of the case
21
make contact in the region of main body
24
, only slightly larger than the width of the region of main body
24
. Under the above-described arrangement, the sides in the region of main body
24
are supported firmly by the end-faces of the rectangular cut
32
. Thus the play can be minimized, and the push-on switches can be mounted at high placement accuracy.
A second method for mounting a push-on switch in the present embodiment is shown in
FIG. 5B. A
push-on switch is held at the overhang
25
, and the case
21
in the region of main body
24
is inserted horizontally into the rectangular cut
32
from the front as indicated by an arrow. The bottom surface of overhang
25
is kept slightly off the upper surface of printed circuit board
31
.
When the back surface of the case in the region of main body
24
touches the rear end-face of cut
32
, the horizontal inserting motion is stopped, and then the push-on switch is lowered as indicated by the arrow until the bottom surface of overhang makes contact with the upper surface of printed circuit board
31
, as shown in FIG.
6
.
Finally when the terminal
26
is connected with the land
34
, an electronic apparatus is completed, with the operating part
29
C protruding from the front edge of printed circuit board
31
.
In accordance with the present method, a push-on switch in the region of main body
24
is first inserted in to a specified location inside the cut
32
of printed circuit board
31
, and then lowered for fixing. Therefore, the back end of a push-on switch can easily be brought to make contact with the rear end-face of the cut
32
.
The cut
32
may be shaped so that the gap between the end-faces gets narrower towards the rear end, with the case
21
also provided with a corresponding form in the region of main body
24
. The above arrangement eases mounting of a push-on switch on a printed circuit board; namely, even if the starting position of the region of main body
24
is slightly dislocated, it proceeds along the narrowing end-faces of the cut
32
, eventually reaching an exact location.
As described in the foregoing, a push-on switch in the present embodiment is mounted on a printed circuit board
31
with only its portion of the overhang
25
protruded above the printed circuit board
31
. So, it will provide an electronic apparatus with additional room for further downsizing and thinning.
Forming a land
34
over an extended area, in a rearward direction away from the push-on switch, may work as a good remedy for a case as shown in
FIG. 7A
, where a push-on switch is inadvertently placed on a printed circuit board
31
slightly dislocated towards the front, or a once-located push-on switch is slightly dislocated during transfer to the next process step during a manufacturing process. With the above-described land
34
of an extended area, a slightly-dislocated push-on switch may be pulled back as indicated by an arrow of
FIG. 7B
when it is soldered, by the effect of surface tension of the solder. Namely, the push-on switches may be self-aligned to the exact position in the cut
32
of printed circuit board
31
. Thus good mounting quality is obtained.
Since the bottom surface of overhang
25
is kept in close contact with the printed circuit board
31
and the back surface in the region of main body
24
is touching the rear end-face of cut
32
, operating force exerted in parallel with the printed circuit board
31
on the operating body
29
is encountered by the rear end-face of the rectangular cut
32
via the region of main body
24
. Therefore, the soldered portion connecting the land
34
and terminal
26
does not have an undesirable mechanical load applied thereto. Reliable electrical ON/OFF performance can be expected over a long period of time, even after pressing actions are repeatedly exerted on the push-on switch.
Furthermore, by adjusting the thickness of the overhang
25
so that the approximate center of pushing part
29
A substantially coincides with the center of printed circuit board
31
in its thickness direction, the operating force can be better absorbed by the printed circuit board. Under the above-described arrangement, stress on the portion of connection terminal
26
can be reduced still further. Thus a connection stability of the push-on switch with a printed circuit board
31
is improved a step further.
Although the above description has been made only with examples where the push-on switches are mounted with their operating parts
29
C protruded from the front edge of a printed circuit board
31
, an entire part of the push-on switch including the operating part
29
C may be mounted instead behind the front edge of a printed circuit board
31
, so that it is operated using an operating member provided in the apparatus side. Or, instead of mounting a push-on switch in a rectangular cut
32
, it may be mounted, for example, in the inside of a through hole of a certain specific form provided in a printed circuit board
31
. Irrespective of the method of mounting, the push-on switch of the present embodiment makes a significant contribution to the downsizing of electronic apparatus.
The above-described methods for mounting may be applied also to other kinds of electronic components besides the push-on switches of the present invention. The mounting method can be readily used for any of the electronic components that have an overhang in the upper part of the case, where the overhang stretches horizontally in the sidewise directions for a distance greater than the size of main body region of the case and is provided with terminals for connection.
The push-on switch in the present embodiment contains an interposed insulating sheet
28
. However, it is not an essential constituent. By eliminating it, the number of components and the manufacturing process steps becomes less, and the total cost lower.
Second Embodiment
FIG. 8
shows a cross-sectional side view of a push-on switch in a second exemplary embodiment of the present invention. The only difference from the first embodiment is that the operating body
41
is made of an elastic material in the present embodiment. The remaining portions are the same as those of the first embodiment; so, the detailed description of the remaining portions is not repeated.
A rubber material, an elastomer or other elastic resin materials can be used for the operating body
41
.
As shown in
FIG. 8
, the operating body
41
is supported by a cover
30
attached on case
21
, with the operating part
41
A protruding through an opening
30
A of the cover
30
. A front surface of flange
41
B, disposed behind the operating part
41
A, makes contact with the rear surface of cover
30
to regulate location of the operating body
41
.
The operating body
41
moves to-and-fro in the case guided by the wall
21
B of case
21
, so that the operating body
41
can push, at the pushing part
41
C, the dome summit
27
A via insulating sheet
28
.
For the other portions, the same constituent parts as in the first embodiment are used, description of which is eliminated here.
Next, operation of the push-on switch in the present embodiment is described
FIG. 8
shows the switch in an OFF state. When the operating body
41
at operating part
41
A is pressed in a direction as indicated with an arrow, the operating body
41
moves horizontally in the rearward direction and this accompanies a deformation due to elastic compression over a portion of the operating body
41
from operating part
41
A to pushing part
41
C. The pushing part
41
C pushes the domed movable contact
27
at the dome summit
27
A via the insulating sheet
28
and the dome summit
27
A sinks. When the pressing force goes beyond a certain level, the domed movable contact
27
reverses with an accompanying click feeling to come in contact with the central fixed contact point
22
at the rear surface of dome summit
27
A. Thus the central fixed contact point
22
and the outer fixed contact points
23
are brought into contact via the domed movable contact
27
. The terminals
26
are electrically connected accordingly to place the push-on switch in an ON state, as shown in FIG.
9
.
When the pressing force is withdrawn, the domed movable contact is
27
restored to its original shape by an elastic restorative force, and returns the operating body
41
to the initial location bringing the switch back to the OFF state as shown in FIG.
8
.
Since the operating body
41
is made of an elastic material in the present embodiment, it provides a longer operating stroke including a certain length due to the deflection in operating body
41
.
An appropriate material may be selected for the operating body
41
to provide desired operating stroke.
A push-on switch in the present embodiment may be fabricated so that an operating body
41
can undergo a further elastic deformation after the push-on switch is brought into an ON state; namely, the push-on switch may provide an over stroke in the pressing operation. In the above-described configuration, however, attention has to be paid to avoid applying too much load to the contact points section formed of the domed movable contact
27
, central fixed contact point
22
and outer fixed contact points
23
.
Furthermore, a push-on switch in the present embodiment may be assembled, by making use of the elastic force of the operating body
41
, in a way that the operating body
41
itself and the domed movable contact
27
are normally pressed backward for a slight amount. Under the above-described way of fabrication, dislocating of assembled components is curtailed. Significance of this way of fabrication is revealed when the push-on switch is used in, for example, a portable electronic apparatus, where generation of abnormal sounds due to rattling of constituent components can be avoided.
The rattling sound as well as contacting noise may be prevented more effectively by disposing an apparatus side operating member always in contact with the operating part
41
A of operating body
41
so that a certain amount of compression force is present therein.
A method for mounting the push-on switch of the present invention and the state after mounting on a printed circuit board remain the same as those in the first embodiment, so description thereof is omitted here.
Although the operating part
41
A, the flange
41
B and the pushing part
41
C in the present embodiment have been formed integrally as a single-piece operating body
41
, it may be fabricated otherwise. Namely, for example, first making the flange part with a solid material and then combining an elastic operating part and an elastic pushing part together; or combining an integrated elastic body constituting the operating part and the pushing part with the flange part.
Third Embodiment
FIG. 10
shows a perspective view of a push-on switch in a third exemplary embodiment of the present invention.
FIG. 11
is an exploded perspective view of the push-on switch.
As shown in the
FIGS. 10 and 11
, the push-on switch in the present embodiment comes without operating body and cover, as compared with the counterpart in the first embodiment.
Namely, an insulating resin case
51
contains a main body
54
of a switch mechanism formed in a front-open recess
51
A, where a central fixed contact point
52
and two outer fixed contact points
53
, which are disposed symmetrically at both sides of the central fixed contact point
52
, are provided integrally by an insert molding method in an inner recess of the case
51
so that these fixed contact points are exposed from a wall surface of the recess. The resin case
51
is provided with an overhang
55
which stretches horizontally in directions towards both sides and towards the rear from the resin case
51
in the upper part of a region corresponding to the region of main body
54
so as to have a size greater than the size of main body region.
The central fixed contact point
52
and the outer fixed contact points
53
are electrically connected respectively with terminals
56
provided on the overhang
55
, like in the first embodiment.
A domed movable contact
27
is housed in the recess
51
A of case
51
with the circumferential edge placed on the outer fixed contact points
53
, so that it opposes the central fixed contact point
52
keeping a certain predetermined clearance from the reverse surface of the dome summit
27
A. And a flexible insulating sheet
28
is provided for sealing the recess
51
A closed and supporting the domed movable contact
27
at the front surface at the dome summit
27
A for regulating the location. the basic structure remains the same as that in the first embodiment.
The above-configured push-on switch operates on the same basic principle s the first embodiment. So, only a brief description is made here.
Since the push-on switch in the present embodiment has no operating part appearing outside, it is operated by operating pressure given, via insulating sheet
28
, to the domed movable contact
27
using an apparatus side operating member (not shown).
When the pressing force goes beyond a certain level, the domed movable contact
27
reverses and is accompanied by a click feeling to come into contact with the central fixed contact point
52
at the rear surface at dome summit
27
A. Thus the central fixed contact point
52
and the outer fixed contact points
53
are brought into electrical contact, and the corresponding terminals
26
are brought into electrical contact.
When the operating pressure is withdrawn, the domed movable contact
27
is restored to its original shape by an elastic restorative force, and the switch returns to an OFF state.
The method for mounting the push-on switch in the present embodiment and the state after mounting on a printed circuit board are the same as in the first embodiment. So, description of thereof omitted here.
As described above, the push-on switches in the present embodiment can be provided using fewer components, and the shape of case
51
can be much simplified, as compared with the first embodiment. Thus a push-on switch that is cheaper and superior in operational function is provided.
Fourth Embodiment
FIG. 12
is a perspective view showing a push-on switch and an electronic apparatus in part, or a printed circuit board on which the switch is mounted, in a fourth exemplary embodiment of the present invention. As compared with that in the first embodiment, a case
61
of the present embodiment is provided with a protrusion
63
for forming a protrusion/recess area in the region of main body
62
.
The protrusion
63
is provided in two places symmetrically located at both sides of the center line with respect to the width of the case
61
; the protrusions
63
reach upward to an overhang
64
, and downward to the level of a skirt line of case
61
.
As to the structure of other parts and the operation, they remain the same as in the first embodiment. So, description thereof is omitted here.
As shown in
FIG. 12
, a cut
66
of a printed circuit board
65
is provided at the rear end with recesses
67
for accepting protrusions
63
of case
61
.
The push-on switch in the present embodiment is mounted on the printed circuit board
65
with the protrusions
63
engaged in the recesses
66
. By being mounted as above, the push-on switch can be held firmly in the place until it is finally fixed by soldering.
When an operating force is exerted in an oblique direction, movement of the switch is resisted by an engaged structure formed of the protrusions and the recesses, besides a pair of side-faces of the cut
66
. Thus the stress due to the oblique force is better absorbed in the present embodiment by the engaged structure, to provide an enhanced mounting strength.
Since the engaged structure keeps the push-on switch fixed firmly at the central zone including its right and left vicinities, where the influence of operating force is the greatest, the mounting stability is significantly increased. Shape, location, numbers, etc. of the engaging structure are optional.
Fifth Embodiment
FIG. 13
is a perspective view in part of an electronic apparatus, showing a push-on switch in a fifth exemplary embodiment of the present invention mounted on a printed circuit board. The push-on switch in the present embodiment differs from the first embodiment in the way a terminal
71
is provided and in the method by which it is mounted on a printed circuit board.
The push-on switch in the present embodiment is mounted on a printed circuit board in a way such that a push-on switch similar to that in the first embodiment is held upside down. Namely, the top surface of the overhang
25
of case
21
in the first embodiment is positioned at the bottom in the present embodiment, and the bottom surface is placed in contact with the upper surface of printed circuit board
72
to be fixed thereon.
In the present embodiment, a connection terminal
71
provided in the overhang
25
is devised so that it can be connected and fixed by soldering on a circuit pattern
73
of printed circuit board
72
.
As to the structure of other parts and the operation, they remains the same as in the first embodiment. So, no detailed description thereof is repeated here.
Since the push-on switch in the present embodiment is disposed on a printed circuit board
72
with the broad contact area of the overhang
25
down, it can stand alone by itself in a stable manner. This means that the soldering and other procedures can be performed with ease, because the push-on switch is positioned stably thereon. And the operating forces may be dispersed by the broad contact area, so the push-on switch does not easily topple down.
Furthermore, the printed circuit board
72
does not need to be provided with a rectangular cut in the present embodiment, which saves a processing cost.
Still further, the cover
74
may be provided with a reinforcement terminal
74
A, as shown in
FIG. 14
, in addition to the terminal
71
. When the reinforcement terminal
74
A is soldered and fixed on a land
76
of printed circuit board
75
, the mounted strength is further enhanced. The reinforcement terminal
74
A may be utilized also for an anti-electrostatic purpose by electrically connecting the land
76
with the grounding line of the electronic apparatus.
As described in the foregoing, the present invention provides a side-push type push-on switch having a superior operational property. It is mounted and fixed on a printed circuit board with a structure where an operating force is encountered by the end-face of the printed circuit board.
Furthermore, mold machining, manufacturing of constituent components, etc. can be conducted with ease and be less expensive in the present invention even when the push-on switches are miniature-size.
Electronic apparatus can still be downsized and thinned by introducing the push-on switches of the present invention.
Claims
- 1. A push-on switch comprising:a case made of an insulating resin and including a main body and an overhang that protrudes outwardly beyond said main body at an upper part of said main body so as to have a size greater than said main body, said case having a forwardly-opening recess; a central fixed contact point and an outer fixed contact point mounted to said case and exposed in said recess; a domed movable contact made of an elastic thin metal sheet housed in said case and having an outer circumference disposed on said outer fixed contact point; an operating body mounted to said case so that said operating body can move said domed movable contact; a cover attached to said case and supporting said operating body; and terminals provided in said overhang and electrically coupled with said central fixed contact point and said outer fixed contact point, respectively.
- 2. The push-on switch of claim 1, wherein said domed movable contact is positioned and held to the case by an insulating flexible sheet provided with one of a sticking agent layer and a pressure sensitive adhesive layer.
- 3. The push-on switch of claim 1, wherein said operating body is provided with an operating part protruding forward through an opening of said cover.
- 4. The push-on switch of claim 3, wherein said operating body is formed of elastic material.
- 5. The push-on switch recited in claim 1, wherein each of said terminals provided in said overhang of said case has an additional portion extending in parallel to said overhang.
- 6. An electronic apparatus including a printed circuit board having a cutout portion, and a push-on switch, said push-on switch comprising:a case made of an insulating resin and including a main body and an overhang that protrudes outwardly beyond said main body at an upper part of said main body so as to have a size greater than said main body, said case having a forwardly-opening recess; a central fixed contact point and an outer fixed contact point mounted to said case and exposed in said recess; a domed movable contact made of an elastic thin metal sheet housed in said case and having an outer circumference disposed on said outer fixed contact point; an operating body mounted to said case so that said operating body can move said domed movable contact; a cover attached to said case and supporting said operating body; and terminals provided in said overhang and electrically coupled with said central fixed contact point and said outer fixed contact point, respectively, wherein said push-on switch is mounted on said printed circuit board in a manner such that said case, in a region corresponding to said main body, fits in said cutout portion of said printed circuit board while a bottom surface of said overhang keeps close contact with an upper surface of said printed circuit board, and said terminals provided in said overhang are connected to circuit patterns formed on said printed circuit board.
- 7. The electronic apparatus of claim 6, wherein the cutout portion of said printed circuit board is shaped to have an opposing pair of end-faces spaced apart by a dimension slightly larger than a width of said main body, andsaid opposing pair of end-faces support the sides of said case at said main body thereof.
- 8. The electronic apparatus of claim 6, wherein a land is provided on said printed circuit board and is slightly spaced from an edge of said cutout portion of said printed circuit board.
- 9. The electronic apparatus recited in claim 6, wherein a back wall of said main body makes contact with an end-face of said cutout portion of said printed circuit board.
- 10. The electronic apparatus of claim 9, wherein said back wall of said main body is formed to have a specific pattern of at least one protrusion and at least one recess, and said printed circuit board is provided at a contact edge in said cutout portion with a counterpart pattern to be engaged with said specific pattern.
- 11. The electronic apparatus of claim 10, wherein a center of said push-on switch is coplanar with a center of said printed circuit board in a direction of thickness.
- 12. The electronic apparatus recited in claim 9, wherein a land is provided on said printed circuit board for connection with one of said terminals of said push-on switch for an extended space stretching rearwardly.
- 13. An electronic apparatus including a printed circuit board having a cutout portion, and a push-on switch, said push-on switch comprising:a case made of an insulating resin and including a main body and an overhang that protrudes outwardly beyond said main body at an upper part of said main body so as to have a size greater than said main body, said case having a forwardly-opening recess; a central fixed contact point and an outer fixed contact point mounted to said case and exposed in said recess; a domed movable contact made of an elastic thin metal sheet housed in said case and having an outer circumference disposed on said outer fixed contact point; an operating body mounted to said case so that said operating body can move said domed movable contact; a cover attached to said case and supporting said operating body; and terminals provided in said overhang and electrically coupled with said central fixed contact point and said outer fixed contact point, respectively, wherein said push-on switch is mounted on a printed circuit board with said overhang of said case in contact thereon, and at least one of said terminals provided in said overhang is connected with a circuit pattern formed on an upper surface of said printed circuit board.
- 14. A method for mounting a push-on switch on a printed circuit board, said push-on switch comprisinga case made of an insulating resin and including a main body and an overhang that protrudes outwardly beyond said main body at an upper part of said main body so as to have a size greater than said main body, said case having a forwardly-opening recess, a central fixed contact point and an outer fixed contact point mounted to said case and exposed in said recess, a domed movable contact made of an elastic thin metal sheet housed in said case and having an the outer circumference disposed on said outer fixed contact point, an operating body mounted to said case so that said operating body can move said domed movable contact, a cover attached to said case and supporting said operating body, and terminals provided in said overhang and electrically coupled with said central fixed contact point and said outer fixed contact point, respectively, said method comprising: inserting said main body of said push-on switch from the upper side into a cutout portion provided at an end of said printed circuit board until a bottom surface of said overhang of said case reaches to make contact with an upper surface of said printed circuit board; and connecting at least one of said terminals to a circuit pattern formed on said upper surface of said printed circuit board.
- 15. A method for mounting a push-on switch on a printed circuit board, said push-on switch comprisinga case made of an insulating resin and including a main body and an overhang that protrudes outwardly beyond said main body at an upper part of said main body so as to have a size greater than said main body, a central fixed contact point and an outer fixed contact point mounted to said case and exposed in said recess, a domed movable contact made of an elastic thin metal sheet housed in said case and having an outer circumference disposed on said outer fixed contact point, an operating body mounted to said case so that said operating body can move said domed movable contact, a cover attached to said case and supporting said operating body, and terminals provided in said overhang and electrically coupled with said central fixed contact point and said outer fixed contact point, respectively, said method comprising: inserting said main body of said push-on switch from the front into a cutout portion provided at an end of said printed circuit board to a certain predetermined location; lowering said case until a bottom surface of said overhang of said case contacts on an upper surface of said printed circuit board; and connecting at least one of said terminals to a circuit pattern formed on said upper surface of said printed circuit board.
- 16. The push-on switch of claim 2, wherein said operating body is provided with an operating part protruding forward through an opening of said cover.
- 17. The push-on switch recited in claim 2, wherein each of said terminals provided in said overhang of said case has an additional portion extending in parallel to said overhang.
- 18. The push-on switch recited in claim 3, wherein each of said terminals provided in said overhang of said case has an additional portion extending in parallel to said overhang.
- 19. The push-on switch recited in claim 4, wherein each of said terminals provided in said overhang of said case has an additional portion extending in parallel to said overhang.
- 20. The electronic apparatus of claim 7, wherein a land is provided on said printed circuit board and is slightly spaced from an edge of said cutout portion of said printed circuit board.
- 21. The electronic apparatus recited in claim 7, wherein a back wall of said main body makes contact with an end-face of said cutout portion of said printed circuit board.
- 22. The electronic apparatus recited in claim 8, wherein a back wall said main body makes contact with an end-face of said cutout portion of said printed circuit board.
- 23. The electronic apparatus recited in claim 10, wherein a land is provided on said printed circuit board for connection with one of said terminals of said push-on switch for an extended space stretching rearwardly.
- 24. The electronic apparatus recited in claim 11, wherein a land provided on said printed circuit board for connection with one of said terminals of said push-on switch for an extended space stretching rearwardly.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-015167 |
Jan 2000 |
JP |
|
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
5-1126 |
Jan 1993 |
JP |