Information
-
Patent Grant
-
6496095
-
Patent Number
6,496,095
-
Date Filed
Thursday, March 8, 200123 years ago
-
Date Issued
Tuesday, December 17, 200222 years ago
-
CPC
-
US Classifications
Field of Search
US
- 337 367
- 337 59
- 337 62
- 337 66
- 337 76
- 337 79
- 337 53
- 337 74
- 337 75
- 337 39
- 337 85
- 337 91
- 337 112
- 337 113
- 337 140
- 337 334
- 337 345
- 029 622
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International Classifications
- H01H3702
- H01H3732
- H01H3746
- H01H3752
-
Abstract
A push button switch includes a box with a button movably inserted in the box and an oscillation member is pivotally connected to a terminal plate. A bimetal plate is connected to the other terminal plate. A curved spring is connected to the oscillation member and a tongue of the button contacts the curved spring so that the bimetal plate contacts the oscillation member when pushing the button. A movable member has a U-shaped member which has an end engaged with an enclosed recessed area in the button. The inner periphery of the recessed area positions the end of the U-shaped member at open and close position. The movable member is pushed by the deformation of the bimetal plate and the U-shaped member is moved from the position in the recessed area.
Description
FIELD OF THE INVENTION
The present invention relates to a push button switch that has simple structure and having an override interruption structure so as to automatically open the circuit in case of the override.
BACKGROUND OF THE INVENTION
Many conventional push buttons with an override interruption structure known to applicant are disclosed in U.S. Pat. Nos. 5,786,742, 5,223,813, 4,937,548, 4,661,667, 5,223,813, 4,931762, 5,451,729 and 4,704,594. U.S. Pat. No. 4,937,548. A thermally deformed bimetal plate is used to open circuit in case of the override. However, the action to open the circuit takes time because the structure for disengagement two contact points is indirectly operated by the bimetal plate so that there is a possibility that the electric current will destroy the electric equipment in case of the override. Furthermore, an additional wire is required between the bimetal plate and a conductive plate. In U.S. Pat. No. 5,786,742, the button is directly connected to the contact point so that the open action for the circuit is not fast enough to timely protect the equipment.
The present invention intends to provide a push button switch that has a simple structure and timely opens the circuit to protect the electric equipment.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a push button switch comprising box having a button movably inserted in an open top of the box. A tubular member extends from an underside of the button and a spring is biased between the tubular member and the box. A tongue extends from an underside of the button and a recessed area is defined in a surface of the tubular member. The recessed area has a polygonal inner periphery and a central member is located in a center of the recessed area. A first terminal plate and a second terminal plate respectively extend from a bottom of the box. A board extends from an inner side of the box and a hole is defined in a surface of the board. Two rods respectively extend from the inner side of the box.
A movable member has two slots and the rods are movably received in the two slots. A U-shaped member has a leg extending through the movable member and engaged with the recessed area. The other leg of the U-shaped member is inserted in the hole in the board. A U-shaped bimetal plate has a central plate located between two legs of the U shaped bimetal plate and a first contact point is connected to the central plate. The two legs of the bimetal plate is fixedly connected to a top of the first terminal plate. The bimetal plate is located beside an end of the movable member. An oscillation member has a first end pivotally connected to the second terminal plate and a second end of the oscillation member has a second contact point connected thereto. A curved spring has an end fixedly connected to the box and the other end of the curved spring is connected to the oscillation member. The tongue contacts the curved spring.
The object of the present invention is to provide a switch that has a movable member which is pushed by the bimetal plate in case of the override and the movement of the movable member shifts a U-shaped member to let the button to jump up.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an exploded view to show the push button switch of the present invention;
FIG. 2
is an exploded view to show a push button and a spring of the present invention;
FIG. 3
is an illustrative view to show an open circuit status of the switch of the present invention;
FIG. 4
is an illustrative view to show a close circuit status of the switch of the present invention;
FIG. 5
is an illustrative view to show an open circuit status of the switch of the present invention when the bimetal plate is deformed in case of the override;
FIG. 6
a
shows the position of a leg of the U-shaped member in the recessed area of the push button when the circuit is in open position;
FIG. 6
b
shows the position of the leg of the U-shaped member in the recessed area of the push button when the button is pushed to close the circuit;
FIG. 6
c
shows the position of the leg of the U-shaped member in the recessed area of the push button when the circuit is in close position;
FIG. 6
d
shows the position of the leg of the U-shaped member in the recessed area of the push button when the button is pushed to open the circuit;
FIG. 7
a
shows that when the metal plate is to be deformed, the leg of the U shaped member is still in the close circuit position the same as that shown in
FIG. 6
c.
FIG. 7
b
shows that when the metal plate is deformed, the leg of the U-shaped member is shifted left, and
FIG. 7
c
shows that when the metal plate is deformed and the circuit is opened, the button jumps up and the leg of the U-shaped member is located at the position the same as that shown in
FIG. 6
a.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to
FIGS. 1
to
3
, the push button switch in accordance with the present invention comprises a box
2
having a button
1
movably inserted in an open top
21
of the box
2
. A tubular member
11
extends from an underside of the button
1
and a hole
110
is defined in an underside of the tubular member
11
so as to receive one end of a spring
14
therein. The other end of the spring
14
contacts an inner side of the box
1
. A tongue
13
extends from an underside of the button
1
and has an inclined surface. A recessed area
12
is defined in a surface of the tubular member
11
and the recessed area
12
has a polygonal inner periphery. A central member
121
is located in a center of the recessed area
12
and a dent
1210
is defined in a top of the central member
12
. A triangle plate
122
extends from the inner periphery of the recessed area
12
and is located above the dent
1210
of the central member
12
.
A first terminal plate
24
and a second terminal plate
25
respectively extend from two slits
22
,
23
defined in a bottom of the box
2
. A board
20
extends from an inner side of the box
2
and a hole
26
is defined in a surface of the board
20
and a recess
211
is defined in an underside of the board
20
. Two rods
27
,
270
respectively extend from the inner side of the box
2
.
A movable member
4
has two slots
42
,
43
defined therethrough and the two rods
27
,
270
are movably received in the two slots
42
,
43
. A U-shaped member
40
has a leg
41
thereof extending through a hole
411
in the movable member
4
and is movably engaged with the recessed area
12
. The other leg
410
of the U-shaped member
40
is inserted in the hole
26
in the board
20
.
A U-shaped bimetal plate
3
has a central plate
32
located between two legs
31
of the U-shaped bimetal plate
3
. A first contact point
34
is connected to the central plate
32
and the two legs
31
of the bimetal plate
3
are fixedly connected to a top of the first terminal plate
24
. The bimetal plate
3
is located beside an end
44
of the movable member
4
.
The second terminal plate
25
has a groove
251
defined in a top thereof and two notches
252
are defined through an inner periphery of the groove
251
. A first end of the oscillation member
5
is pivotally received in the groove
251
and two protrusions
51
extend from the first end of the oscillation member
5
, the two protrusions
51
engaged with the two notches
252
. Accordingly, the oscillation member
5
is pivoted about the first end of the oscillation member
5
. A second end of the oscillation member
5
has a second contact point
54
connected thereto. A curved spring
55
has an end fixedly received in a notch
212
of the board
20
and the other end of the curved spring
55
has two lugs
551
extending through slots
52
in the oscillation member
5
. The inclined surface of the tongue
13
contacts the curved spring
55
. An L-shaped spring
45
has one end engaged with the recess
211
and the other end of the L-shaped spring
45
pushes the U-shaped member
40
toward the recessed area
12
of the button
1
. A cover
20
is connected to the box
2
to receive the parts mentioned above in the box
2
by screws or rivets
202
extending through holes
201
in the cover
20
and engaged with the holes
29
in the box
2
.
When the circuit is in open status, the button
1
is moved to the highest position by the spring
14
and the leg
41
is located at a lowest position in the recessed area
12
as shown in
FIG. 6
a.
As shown in
FIG. 4
, when the button
1
is pushed to close the circuit, the curved spring
55
is pushed by the downward movement of the tongue
13
, the oscillation member
5
is then pivoted to let the second contact point
54
to contact the first contact point
34
to form a close circuit. In the mean while, referring to
FIG. 6
b
, the leg
41
of the U-shaped member
40
is moved counter clockwise. When the user release the button
1
, the button
1
slightly moves upward and the leg
41
is in the dent
1210
and located between the triangle plate
122
and the central member
121
as shown in
FIG. 6
c
. When the button
1
is pushed again, the circuit will be opened and the leg
41
is moved as shown in
FIG. 6
d.
FIG. 5
shows that the bimetal plate
3
is deformed in case of the override, a top of the bimetal plate
3
is deformed toward the left to push the end
44
of the movable member
4
, and the second contact point
54
and the first contact point
34
are separated. The leg
41
of the U-shaped member
40
is then shifted from the position in
FIG. 7
a
to the position in
FIG. 7
b
. A boss
28
extends from an inside of the box
1
and contacts the central plate
32
of the bimetal plate
3
when the bimetal plate
3
is deformed. The boss
28
prevents the central plate
32
of the bimetal plate
3
from being over deformed.
When the button
1
jumps up, the leg
41
of the U-shaped member
40
is moved to the position as shown in
FIG. 7
c.
While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope and spirit of the present invention.
Claims
- 1. A push button switch comprising:a box having a button movably inserted in an open top of said box, a tubular member extending from an underside of said button and a spring biased between said tubular member and said box, a tongue extending from an underside of said button and a recessed area defined in a surface of said tubular member, said recessed area having a polygonal inner periphery and a central member located in a center of said recessed area, a first terminal plate and a second terminal plate respectively extending from a bottom of said box, a board extending from an inner side of said box and a hole defined in a surface of said board, two rods respectively extending from said inner side of said box; a movable member having two slots defined therethrough and said two rods movably received in said two slots, a U-shaped member having a leg thereof extending through said movable member and movably engaged with said recessed area, the other leg of said U-shaped member inserted in said hole in said board; a U-shaped bimetal plate having a central plate located between two legs of said U-shaped bimetal plate, a first contact point connected to said central plate and said two legs of said bimetal plate fixedly connected to a top of said first terminal plate, said bimetal plate located beside an end of said movable member, and an oscillation member having a first end pivotally connected to said second terminal plate and a second end of said oscillation member having a second contact point connected thereto, a curved spring having an end fixedly connected to said box and the other end of said curved spring connected to said oscillation member, said tongue contacting said curved spring.
- 2. The switch as claimed in claim 1, wherein said second terminal plate has two notches defined in a top thereof and two protrusions extend from said first end of said oscillation member, said two protrusions engaged with said two notches.
- 3. The switch as claimed in claim 2, wherein said second terminal plate has a groove defined in said top thereof and said first end of said oscillation member pivotally received in said groove.
- 4. The switch as claimed in claim 1, further comprising a recess defined in an underside of said board and an L-shaped spring has one end engaged with said recess, the other end of said L-shaped spring pushing said U-shaped member toward said recessed area of the button.
- 5. The switch as claimed in claim 1, further comprising an inclined surface defined in said tongue and said inclined surface contacting said curved spring.
- 6. The switch as claimed in claim 1, wherein said tubular member has a hole defined in an underside thereof so as to receive one end of said spring therein.
- 7. The switch as claimed in claim 1, further comprising a dent defined in a top of said central member and a triangle plate extends from said inner periphery of said recessed area, said triangle plate located above said dent of said central member.
- 8. The switch as claimed in claim 1, further comprising a boss extending from an inside of said box and contacting said central plate of said bimetal plate when said bimetal plate is deformed.
US Referenced Citations (13)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3313465 |
Oct 1984 |
DE |
2766007 |
Jan 1999 |
FR |