Electricity: electrothermally or thermally actuated switches – Electrothermally actuated switches – With bimetallic elements
Reexamination Certificate
2002-02-26
2003-09-09
Vortman, Anatoly (Department: 2835)
Electricity: electrothermally or thermally actuated switches
Electrothermally actuated switches
With bimetallic elements
C337S059000, C337S066000, C337S072000
Reexamination Certificate
active
06617952
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a switch that includes an N-shaped spring connected to an end of a bimetal plate. An adjusting screw is engaged with one end of the N-shaped spring so as to adjust the position of the end of the spring.
BACKGROUND OF THE INVENTION
A conventional switch is shown in
FIGS. 1 and 2
and includes a base
6
having an open top to receive a button
7
therein. Three terminal plates
61
,
62
and
63
extend through three slots defined through the bottom of the base
6
. The terminal plate
62
has a first contact point
922
and a bimetal plate
92
is located above the terminal plate
62
. A second contact point
921
is connected to a bottom of the bimetal plate
92
. An N-shaped spring
91
has one end pivotally connected to a recess
920
in one end of the bimetal plate
92
, and the other end of the spring
91
is pivotally received in a groove
60
in an inside of the base
6
. A swing member
83
pivotally connected between two opposite insides of the base
6
and a cone-shaped protrusion extends from an inside of the groove of the swing member
83
so as to define two recesses
831
separated by the protrusion. A connection plate
93
is pivotally connected to an end of the swing member
83
and the bimetal plate
92
. A pushing rod
81
has a top end connected to an underside of the button
7
and a lower end of the pushing rod
81
can be inserted in either of the two recesses
831
in the swing member
83
. A spring
82
is mounted to the pushing rod
81
to allow the button
7
to return.
As shown in
FIG. 3
, when pushing the button
7
, the pushing rod
81
pushes the swing member
83
counter clockwise so that the two contact points
921
,
922
contact and the circuit is closed. The bimetal plate
92
is maintained its position after the N-shaped spring
91
is deformed below its critical deformation ling “L”, and the button
7
is biased upward by the spring
82
. As shown in
FIGS. 4 and 5
, when pushing the button
7
again, the pushing rod
81
is pivoted the swing member
83
clockwise, and the two contact points
921
,
922
are separated again to open the circuit.
When the current overrides, the bimetal plate
92
is supposed to be deformed and overcomes the force of the N-shaped spring
91
to separate the two contact points
921
,
922
. However, the spring force of the N-shaped spring
91
could be too large to be overcome by the deformation of the bimetal plate
92
. The deformation efficiency of the bimetal plate
92
could not be large enough to provide enough deformation to the bimetal plate
92
such that the N-shaped spring
91
does not change its position and the circuit cannot be opened in time.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a switch comprising a base having a button on a top thereof and three terminal plates respectively extend through the bottom of the base. A groove is defined in an inside of the base and an adjusting hole is defined in the base and communicates with the groove. A first contact point is connected to one of the terminal plates.
A bimetal plate is located in the base an N-shaped spring has one end thereof engaged with the groove in the inside of the base, and the other end of the N-shaped spring is pivotally connected to the bimetal plate.
A swing member is pivotally connected between two opposite insides of the base and a cone-shaped protrusion extends from a top of the swing member so as to define two notches separated by the protrusion. A connection plate is connected between an end of the swing member and the bimetal plate.
A pushing rod has a spring mounted thereto and is located between the button and the swing member. A lower end of the pushing rod is located in one of the two notches in the swing member.
An adjusting member is movably engaged with the adjusting hole and an end of the adjusting member contacts the N-shaped spring in the groove.
The primary object of the present invention is to provide a switch having an adjusting member which is movably engaged with the base of the switch so as to adjust the position of an N-shaped spring to ensure the deformation of the bimetal plate is able to overcome the spring force of the N-shaped spring when the current overrides.
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, a preferred embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an exploded view to show a conventional switch;
FIG. 2
is a cross sectional view to show the conventional switch is in open circuit status;
FIG. 3
is a cross sectional view to show the button of the conventional switch is pushed to close the circuit;
FIG. 4
is a cross sectional view to show the button of the conventional switch returns to its original position when the circuit is closed;
FIG. 5
is a cross sectional view to show the button of the conventional switch is pushed again to open the circuit;
FIG. 6
is an exploded view to show the switch of the present invention;
FIG. 7
is a cross sectional view to show the switch in open circuit status;
FIG. 8
shows that the bimetal plate is deformed when the current overrides and the two contact points are separated;
FIG. 9
is an exploded view to show another embodiment of the switch of the present invention;
FIG. 10
is a cross sectional view to show the switch of the embodiment as illustrated in
FIG. 9
is in close circuit status, and
FIG. 11
shows that the bimetal plate of the switch of the embodiment as illustrated in
FIG. 9
is deformed when the current overrides and the two contact points are separated.
REFERENCES:
patent: 3686602 (1972-08-01), Jullien-Davin
patent: 3768057 (1973-10-01), Sekira et al.
patent: 4990882 (1991-02-01), Peter
patent: 5223813 (1993-06-01), Cambreleng et al.
patent: 5262748 (1993-11-01), Tsung-Mou
patent: 5498846 (1996-03-01), Chin
patent: 5889457 (1999-03-01), Hsu et al.
patent: 6072381 (2000-06-01), Yu
patent: 6275134 (2001-08-01), Chen
patent: 6353526 (2002-03-01), Pellon
patent: 6445273 (2002-09-01), Yu
patent: 647094 (1984-12-01), None
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