Electricity: magnetically operated switches – magnets – and electr – Electromagnetically actuated switches – Polarity-responsive
Reexamination Certificate
2000-10-25
2002-07-30
Donovan, Lincoln (Department: 2832)
Electricity: magnetically operated switches, magnets, and electr
Electromagnetically actuated switches
Polarity-responsive
C335S080000
Reexamination Certificate
active
06426689
ABSTRACT:
This application is based on a Japanese Patent Applications Hei. 11-304734 filed on Oct. 26, 2000, Hei. 11-322700 filed on Nov. 12, 1000 and 2000-182211 filed on Jun. 16, 2000, herein cooperated by reference.
BACKGROUND OF INVENTION
1. Field of Application
The present invention relates to an electromagnetic relay constituted by a yoke, a coil portion wound onto the yoke, an armature toggled and provided with respect to the yoke, and a moving contact and a fixed contact which are brought into a contact and separation state depending on the toggle motion of the armature.
2. Related art
FIGS. 1
to
3
show a conventional electromagnetic relay of this type. The electromagnetic relay comprises a yoke C having a winding space divided by a coil bobbin A, a coil B wound thereon and magnetic pole portions C
1
and C
2
provided on both ends, a pair of armatures D
1
and D
2
which are attracted into and separated from the magnetic pole portions C
1
and C
2
of the yoke C to be rotated depending on the excitation state of the coil B, a fixed contact plate E provided with a fixed contact E
1
, a movable spring F provided with a moving contact F
1
opposite to the fixed contact E
1
, and a card G linked to the armatures D
1
and D
2
for displacing the movable spring F such that the moving contact F
1
abuts on or separates from the fixed contact E
1
depending on the rotating operation of the armatures D
1
and D
2
.
The yoke C forms a coil block CC together with the coil bobbins A and B. Moreover, the armatures D
1
and D
2
interpose a permanent magnet H therebetween, and is formed of a molding material integrally with the permanent magnet H. Thus, an armature block DD is formed. A portion J thus formed integrally is provided with a support portion J
1
rotatably supported on a body K in which parts such as the armature block DD and the coil block CC are arranged, and furthermore, is provided with a lever J
2
extended and linked to one of ends of the card G having the other end connected to the movable spring F.
The lever J
2
is connected to the yoke C through an adjusting spring L to be rotatably supported in a state in which a clearance GG is formed between both magnetic pole portions C
1
and C
2
of the yoke C respectively. The clearance GG between the magnetic pole portions C
1
and C
2
of the yoke C and the armatures D
1
and D
2
is regulated by properly changing the shape of the adjusting spring L. By thus regulating the clearance GG, a working voltage of the abutting and separating operation of both contacts E
1
and F
1
can be regulated so that a sensitivity of the abutting and separating operation of the contacts E
1
and F
1
can be regulated.
When a current is caused to flow in a preset direction so that the coil B is excited, an end D
11
of the armature D
1
is attracted into the magnetic pole portion C
1
on one end of the yoke C and the other end D
22
of the armature D
2
is attracted into the magnetic pole portion C
2
on the other end of the yoke C such that a closed magnetic circuit is formed. Consequently, the armature block DD is rotated clockwise in FIG.
17
. As a result, the card G linked to the lever J
2
of the armature block DD is driven toward the movable spring F, and the movable spring F connected to the driven card G is displaced toward the fixed contact plate E so that the moving contact F
1
of the movable spring F abuts on the fixed contact E
1
of the fixed contact plate E. When the excitation of the coil B is stopped, this state is held.
When a current is caused to flow in a direction reverse to the above-mentioned direction so that the coil B is excited in this state, an end D
12
of the armature D
1
is attracted into the magnetic pole portion C
2
on the other end of the yoke C and one end D
21
of the armature D
2
is attracted into the magnetic pole portion C
1
on one end of the yoke C such that a closed magnetic circuit is formed. Consequently, the armature block DD is rotated counterclockwise in FIG.
2
. As a result, the card G linked to the lever J
2
of the armature block DD is driven in such a direction as to go away from the movable spring F, and the movable spring F connected to the driven card G is displaced apart from the fixed contact plate E so that the moving contact F
1
of the movable spring F is separated from the fixed contact E
1
of the fixed contact plate E. When the excitation of the coil B is stopped, this state is held.
With such a structure, however, the armature block DD is positioned in three points, that is, the magnetic pole positions B
1
and B
2
and the fulcrum J
1
. Therefore, a variation in the dimensions of parts causes a clearance to be generated between the end of the magnetic pole portion C
2
and the armature D
22
of the armature block J in either of the magnetic pole positions B
1
and B
2
(the B
2
side in an example of
FIG. 3
) as shown in FIG.
3
. As a result, a fluctuation in a magnetic characteristic is increased so that a shock resistance is deteriorated. Moreover, it is very difficult to regulate a sensitivity.
In this phenomenon, the following troublesome are to be caused , as shown in
FIG. 2
, the clearance GG is formed in two portions between the armatures D
1
and D
2
and the magnetic pole portions C
1
and C
2
of the yoke C. Therefore, in a state in which the sensitivity of the abutting and separating operation of the contacts E
1
and F
1
is regulated, the clearance GG in at least one of the two portions remains so that a variation in suction force is increased. Consequently, it is hard to regulate the sensitivity of the abutting and separating operation of the contacts E
1
and F
1
.
SUMMARY OF INVENTION
The invention has been made in consideration of the circumstances and has an object to provide an electromagnetic relay in which a fluctuation in a magnetic characteristic is small, a shock resistance is enhanced and a sensitivity can be regulated easily.
Another object is to provide an electromagnetic relay capable of easily regulating a sensitivity of the abutting and separating operation of both contacts.
In order to solve the problem, a first aspect of the invention is directed to an electromagnetic relay comprising a yoke having both ends bent in one direction, a coil portion wound onto a central part between the ends of the yoke, a permanent magnet provided between the ends of the yoke, an armature formed to have a greater length than that between the ends of the yoke and provided on the one direction side with respect to the permanent magnet, and a hinge spring capable of causing both end sides of the armature to be toggled with respect to the ends of the yoke, thereby integrally fixing the permanent magnet and the armature, wherein a protrusion is provided between the permanent magnet and the armature.
With such a structure, the position of the armature is determined by two points of the protrusion and either of the positions of magnet poles. Therefore, an unnecessary clearance is not generated so that a magnetic gap is not caused. Consequently, a fluctuation in a magnetic characteristic is reduced so that a shock resistance can be enhanced. Moreover, a sensitivity can be regulated easily.
The electromagnetic relay according to the first aspect of the invention may further comprise an auxiliary yoke formed like a plate having a length which is almost equal to the length between the ends of the yoke and provided on a side reverse to the one direction with respect to the permanent magnet, the permanent magnet being formed like a plate having a smaller length than that between the ends of the yoke, the armature being formed like a plate and having the protrusion on a face opposed to the permanent magnet, the hinge spring being formed to have a central part attached to a face on the one direction side in the armature and both side parts extended from the central part in a direction reverse to the one direction, attached to both side faces of the auxiliary yoke respectively, and having both side parts interposing the permanent magnet therebetween, and the permanent magnet,
Kamitani Fumihiro
Matsui Osamu
Motoyama Masanori
Nakagawa Masafumi
Nishikawa Toyotaka
Donovan Lincoln
Matsushita Electric & Works Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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