Electricity: circuit makers and breakers – Solid contact – Membrane type
Reexamination Certificate
2002-02-12
2003-08-05
Friedhofer, Michael (Department: 2832)
Electricity: circuit makers and breakers
Solid contact
Membrane type
C200S512000, C200S513000, C200S00100B
Reexamination Certificate
active
06603086
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a dome switch having multiple switching function.
2. Description of the Related Art
A two-step switch is used frequently for a window regulator switch in a car. The first step switch operation, pushed by a finger with click feeling, makes a window glass moved and if the finger is left from the switch on the condition, the window glass is stopped. However, when pushing the switch more over the first step switch operation, the window glass moves continuously until reaching to a specified position (top end or bottom end) even if the finger is left from the switch.
Such two-step switch is usually constituted with combining at least two single switches. An example of a rocker-type combined switch, applied by the two-step switch (example of two rocker-type combined switches mounted on) is shown in
FIGS. 12
,
13
A,
13
B and
13
C.
FIG. 12
is an exploded perspective view of the switch.
FIGS. 13A
,
13
B and
13
C are sectional views of one two-step switch for describing its actions.
A switch-operating portion
82
, mounted on a cover
81
, is pivoted on a shaft
83
capably of rocking. The switch-operating portion
82
is provided inside thereof with cam portions
82
a
,
82
a
′ for moving pins
82
b
,
82
b
′ up and down by rocking the switch-operating portion
82
. The switch-operating portion
82
is provided at the back side thereof near the cam portions
82
a
,
82
a
′ with a concave cam portion
82
c
for returning the switch-operating portion
82
to a neutral position (position shown in FIG.
13
A), which is in a condition of OFF (electrically nonconductive condition) on single switches
87
,
87
′, by combined action of the concave cam
82
, a restraining pin
84
and a spring
84
a
when an operator finger is left from the switch-operating portion
82
.
An electric circuit body
85
, covered by a cover
81
, is generally provided with an electric circuit (not shown) and an electric contact. A rubber contact
86
is fixed by a rubber contact locking hole
85
a
of the electric circuit body and a locking piece
86
a
of the rubber contact
86
.
When single switches
87
,
87
′,
88
and
88
′, mounted on positions corresponding to contacts for rubber contacts on the electric circuit body
86
, are pushed and deformed, electrodes provided at the side of the electric circuit body
85
on the single switches contact respectively with the contacts of the electric circuit body
85
and then the switches turn ON to be electric conductive.
The single switches
87
(
87
′) and
88
(
88
′) have deferent stroke length to contact with the electric contacts.
When an operator pushes an arrow portion of the switch-operating portion
82
, shown in
FIG. 13A
, the switch-operating portion
82
sways to be in a condition shown in FIG.
2
B. In the condition, a pin
82
b
is pushed down by the cam
82
a
and a single switch
87
is pushed so that a first contact (not shown) in the electric circuit body
85
turns ON to be electric conductive. The operator can perceive the single switch
87
turning ON by operation feeling of deformation of a rubber portion of the single switch
87
.
When the operator pushes down more the switch-operating portion
82
, the switch-operating portion
82
sways more to be in a condition shown in FIG.
13
C. In the condition, not only the single switch
87
but also the single switch
88
turn ON to be electric conductive.
After that, when the operator moves the finger away from the switch-operating portion
82
, the switch-operating portion
82
returns to a neutral position (position shown in FIG.
13
A and the single switches
87
,
88
turn OFF.
Thus, operating a left side (an arrow portion) of the switch-operating portion
82
, three conditions which are both single switches
87
,
88
OFF (OFF+OFF), only single switch
87
ON (ON+OFF) and both single switches
87
,
88
ON (ON+ON) can be given to control various operations with relays or control circuits sensing conditions of single switches.
Describing above the example of operating the left side in a figure of the switch-operating portion
82
, in case of operating a right side of the switch-operating portion
82
, firstly a single switch
87
′ turns ON and secondly a single switch
88
′ turns ON.
In such two-step switch, a rubber contact locking piece projects from a rear surface of an electric circuit body to be an obstacle to mount the electric circuit body on a surface in an equipment with a double-side adhesive tape or the like. Therefore, getting watertight structure is hindered and also getting thinner thickness of a single switch portion becomes difficult. Two respective single switches are required to have three conditions which are OFF+OFF, ON+OFF and ON+ON so that miniaturization of the single switch is difficult.
In a process from the first step to the second step, a reaction force by compressive elasticity of a rubber portion of the single switch
87
is relative strong to be difficult to sense securely the operation of the switch-operating portion by only operating feeling when the two single switches turn ON.
Objects to be Solved
This invention has been accomplished to overcome the above drawbacks and an object of this invention is to provide a switch having multiple switching functions to be easily miniaturized, watertight and compact.
SUMMARY OF THE INVENTION
How to Attain the Object
In order to attain the objects, according to an aspect of this invention, there is provided a dome switch including a single switch comprising a front sheet having a domed projection projecting outside, being reversed to a back side and provided at the back side with an electrode; an electric circuit body having an electric contact to contact with an electrode provided on the domed projection when the domed projection is turned over; and a domed convex portion provided near the center of the domed projection. In process of pushing the convex portion, firstly the projection is turned over and an electrode provided near the periphery of the convex portion at the back side of the front sheet contacts with the electric contact provided on the electric circuit body and secondly an electrode provided near the center of the domed convex portion at the back side of the front sheet contacts with the electric contact provided on said electric circuit body.
In the above-mentioned structure, the dome switch can be thinner and more compact and water-tighten easily. Furthermore, any locking piece provided on a back side of the electric circuit body is not required, then the dome switch can be mounted easily on a surface of an equipment.
According to an other aspect of the invention, there is provided the dome switch which comprises the dome switch as referred to above, wherein the domed convex portion has a structure capable to turn over to the back side of the front sheet. In the above-mentioned structure, an operator can confirm an action of a second step switch by feeling and then more secure operation can be done.
According to further aspect of the invention, there is provided the dome switch which comprises the dome switch as referred to above, and has a plurality of the single switches. In the above-mentioned structure, more complicated function and operation can be given to keep compact size.
According to a more other aspect of the invention, there is provided the dome switch which comprises the dome switch as referred to above all, and is provided between the front sheet and the electric circuit body with a spacer sheet formed with a throughhole for ensuring contact between the electrode at the back side of the front sheet and the electric contact of the electric circuit body in the single switch to prevent deformation of the front sheet.
In the above-mentioned structure, deformation of the front sheet is prevented for a lot of repeat operation so that durability and reliability of the switch are extremely improved.
According to a further aspec
Kawaguchi Kenichiro
Kubota Minoru
Mori Seiji
Armstrong Westerman & Hattori, LLP
Friedhofer Michael
Yazaki -Corporation
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