Switching apparatus

Details Switching apparatus Switching apparatus

1999-07-26

2001-09-25

Fleming, Fritz (Department: 2836)

Electricity: electrical systems and devices

Control circuits for electromagnetic devices

C361S160000

Reexamination Certificate

active

06295191

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a switching apparatus having electrodes which can be placed into and out of contact with each other for opening and closing a pair of electrodes, and more particularly, it relates to improving the efficiency in driving a switching apparatus with electromagnetic repulsion.
2. Description of the Related Art
FIGS.
8
(
a
) and
8
(
b
) show something analogous to a conventional switching apparatus utilizing electromagnetic repulsion which is, for example, described in speech No. 260 entitled “Switching Characteristic of Novel High-Speed Switch.” The speech was made at the Japanese National Convention of the Department of Industrial Application of the Electric Society at the year of 1996.
In FIGS.
8
(
a
) and
8
(
b
), a switching apparatus includes a switch
1
having a movable electrode
5
and a stationary electrode
6
which can be placed into and out of contact with each other, a repulsion unit
2
, an opening coil
3
a
for inducing current in the repulsion unit
2
, a closing coil
3
b
for inducing a current in the repulsion unit
2
, a movable shaft
4
coupled to the movable electrode
5
, a terminal
7
connected to the movable electrode
5
and the stationary electrode
6
, a pair of pressurizing springs
8
a
,
8
b
for urging the movable electrode
5
in a direction to contact the stationary electrode
6
through the movable shaft
4
, and an auxiliary switch
9
operably connected with the switch
1
through the movable shaft
4
. The repulsion unit
2
and the movable electrode
5
are fixedly coupled to the movable shaft
4
, and disposed in a concentric relation to the electrodes. The opening coil
3
a
and the closing coil
3
b
are connected to a current supply (not shown) for generating magnetic fields. Moreover, the movable shaft
4
passes through a support member S for sliding movement relative thereto. The support member S supports the opening coil
3
a
and the closing coil
3
b
in opposition to each other with the repulsion unit
2
disposed therebetween.
In this connection, note that FIG.
8
(
a
) shows a closed state of the movable and stationary coils
6
a
,
6
b
, while FIG.
8
(
b
) shows an open state of them.
Moreover,
FIG. 9
shows the load characteristics of the pressurizing springs
8
a
and
8
b
and a combined load thereof. Reference numeral
40
denotes the load characteristic of the pressurizing spring
8
a
, and
41
denotes the load characteristics of the pressurizing spring
8
b
. Reference numeral
42
denotes the combined load of the pressurizing springs
8
a
and
8
b.
The pressurizing springs
8
a
and
8
b
are so arranged as to generate a combined load
42
. Specifically, as shown in
FIG. 9
, the pressurizing springs
8
a
and
8
b
generate a load in a direction to close the movable and stationary contacts
5
,
6
of the switch
1
within a range of deflection from an intermediate position to a closed position of the combined load. Another load will be generated in a direction to open the movable and stationary contacts
5
,
6
of the switch within a range of deflection from the intermediate position to an open position of the combined load.
Next,an opening action for the switch
1
will be described. In a closed state of the switch
1
shown in FIG.
8
(
a
), a pulsating current flows from the magnetic field generation current supply (not shown) into the opening coil
3
a
. This causes an induction current to flow into the repulsion unit
2
, thereby inducing magnetic fields in a direction opposite magnetic fields generated by the opening coil
3
a.
Due to the interaction between the magnetic fields induced by the opening coil
3
a
and the magnetic fields induced by the repulsion unit
2
, the repulsion unit
2
undergoes electromagnetic repulsion to repulse the opening coil
3
a.
Due to the electromagnetic repulsion, the movable shaft
4
and the movable electrode
5
fixed to the repulsion unit
2
together act in a direction of repulsion, so that In
FIG. 9
, the magnitude of deflection of the pressurizing spring
8
a
is changed from a value permitting the spring to lie at the closed position, to a value permitting the spring to lie at the intermediate position. With the change in the magnitude of deflection, the load characteristic
42
of the pressurizing spring
8
a
deteriorates. When the pressurizing spring
8
a
warps to go beyond the intermediate position, the load characteristic
42
provides a load oriented in a direction of opening. When the magnitude of warp assumes a value permitting the spring to lie at the open position, the switch
1
remains open as shown in FIG.
8
(
b
).
Next, a closing action will be described. In an open state of the switch shown in FIG.
8
(
b
), when a pulsating current flows into the closing coil
3
b
, magnetic fields are induced therein. This causes an induction current to flow into the repulsion unit
2
. Thus, the repulsion unit
2
undergoes electromagnetic repulsion to repulse the closing coil
3
b
. Due to the electromagnetic repulsion, the movable shaft
4
and the movable electrode
5
fixed to the repulsion unit
2
act in the direction of repulsion. In
FIG. 9
, the magnitude of deflection of the pressurizing spring
8
b
changes from a value permitting the spring to lie at the closed position to a value permitting it to lie at the intermediate position. With the change in the magnitude of deflection, the load characteristic
42
improves. When the pressurizing spring
8
b
is deflected to go beyond the intermediate position, the load characteristic
42
provides a load oriented in a direction of closing. When the magnitude of deflection assumes a value permitting the spring to lie at the closed position, the switch
1
is closed as shown in FIG.
8
(
a
).
In the conventional switching apparatus, as mentioned above, the magnetic field strength provided by the repulsion unit
2
due to induction is smaller than that provided by supplying current directly to an electric circuit. Consequently, electromagnetic repulsion stemming from the interaction between magnetic fields induced by a coil and those induced in the repulsion unit does not occur effectively. Moreover, in order to increase the magnetic field strength, the number of turns of the coil has to be increased, or pulsating current output has to be increased, thus requiring a large power supply. This poses a problem in that an entire device has to be designed on a large scale.
Moreover, in the conventional switching apparatus, high driving efficiency is realized by utilizing electromagnetic repulsion derived from the interaction between magnetic fields induced by the coils and those induced in the repulsion unit. When an opening or closing action is carried out, it becomes necessary for each coil to receive the supply of pulsating current from a power supply. This is disadvantageous in terms of costs and compactness of the device.
SUMMARY OF THE INVENTION
Accordingly, the present invention is intended to obviate the foregoing problems as encountered with the conventional switching apparatus, and has for its object to provide a novel and improved switching apparatus capable of suppressing energy required for switching and being designed compactly by reducing the size of a driving power supply.
Another object of the present invention is to provide a novel and improved switching apparatus which requires a reduced number of power supplies and hence can be produced and operated at reduced costs.
Bearing the above objects in mind, according to the present invention, there is provided a switching apparatus comprising: a switch unit having a stationary electrode and a movable electrode that is movable toward and away from the stationary electrode; a movable coil fixedly mounted on a movable shaft coupled to the movable electrode; a stationary coil disposed in opposition to the movable coil; a power supply for supplying an excitation current to the stationary and movable coils so as to move the movable coil toward or away from the stat

Affiliated with

Also associated with

Rating

Switching apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Switching apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Switching apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2445731