Electromagnetic relay

An electromagnetic relay is provided with a movable contact sloped at a prescribed angle relative to an attracted face of an armature and a fixed contact sloped at a prescribed angle relative to an attracting face of a core. In this electromagnetic relay, it is possible to contact the movable and fixed contacts slidingly each other even when the armature is attached so as to be in contact with a frame.

BACKGROUND OF THE INVENTION 
1. Field Of The Invention 
This invention relates to an electromagnetic relay used for working a 
movable contact and for opening and closing an electric circuit by 
exciting a coil. 
2. Description Of The Prior Art 
Heretofore, there has been used an electro magnetic relay as shoen in FIG. 
5, for example. 
This conventional relay 100 shown in the figure is fixed with terminals 103 
and 104 having fixed contacts 101 and 102 facing each other to a base 105 
and is fixed to the base 105 with a frame 106 for forming a magnetic path. 
Said frame 106 is attached with a coil 107 for excitation. 
A L-like shaped conductive plate 108 having stiffness is engaged to a 
projection 106a provided on the upper side of the frame 106 in FIG. 5 at 
one end thereof, and is attached to an armature 109 at another end 
thereof. The armature 109 is suspended in movable round the one end of the 
L-shaped plate 108 engaged to the projection 106a at the state in which 
the armature 109 is separated from an end 106b of the frame 106 by the 
plate 108. 
A tension spring 110 is engaged between the upper end of the armature 109 
and a hook 106c provided to the upper end of the frame 106 in the right 
side in FIG. 5, and said armature 109 is attached with a movable contact 
112 through a movable contact plate 111. Said movable contact 112 is 
disposed so that an extension line A of the armature 109 in the directions 
of the terminals 103 and 104 may be parallel with extension lines B and B 
of the terminals 103 and 104 in the direction of the armature 109 
approximately. And in this state, the movable contact 112 is so designed 
as to contact with or discontact from the fixed contacts 101 and 102 
provided to the terminals 103 and 104 respectively. 
And either end of a wound wire 107a of the coil 107 is connected 
respectively to terminals 113 and 114 fixed to the base 105, and one end 
of a lead wire 115 is connected to the movable contact plate 111 and 
another end of the lead wire 115 is connected to a terminal 116 fixed to 
the base 105. 
In an unexcited state of the coil 107 as shown in the figure, the armature 
109 is energized in the clockwise direction by elasticity of the tension 
spring 110 round the one end of the L-shaped plate 108 and the movable 
contact 112 is in contact with the fixed contact 101 in the left side in 
FIG. 5, so that the terminal 116 is connected electrically with the fixed 
contact 101 in the left side in FIG. 5. 
In the state, supplying a prescribed electric current to the coil 107 
through the terminals 113 and 114 by changing a switch (not shown), 
magnetic flux is generated by the excitation of the coil 107, so that the 
armature 109 is attracted rightward in FIG. 5. Thereby, the armature 109 
moves rotatively in the anticlockwise direction against the elasticity of 
the tension spring 110, and the movable contact 112 attached to the 
armature 109 through the movable contact plate 111 separates from the 
fixed contact 101 on the left side in FIG. 5 and cones in contact with the 
fixed contact 102 on the right side in FIG. 5. Accordingly, the terminal 
116 of the movable contact 112 is disconnected electrically from the fixed 
contact 101 on the left side in FIG. 5 and is connected electrically with 
the fixed contact 102 on the right side in FIG. 5. 
And, in this state, intercepting the power supply through the terminal 113 
and 114 for the coil 107 by changing the switch (not shown), the coil 107 
becomes into unexcited state and discountinues to attract the armature 
109. Therefore, the armature 109 moves rotatively in the clockwise 
direction by the elasticity of the tension spring 110, and so the movable 
contact 112 separates from the fixed contact 102 on the right side in FIG. 
5 and comes in contact with the fixed contact 101 on the left side in FIG. 
5. Thereby, said movable contact 112 returns to the state shown in FIG. 5. 
Hereupon, said movable contact 112 moves along a line shown with arrow C in 
FIG. 5. Therefore, when the movable contact 112 comes in contact with the 
fixed contact 102 on the right side between the respective fixed contacts 
101 and 102 shown in FIG. 5, said movable contact 112 comes in contact 
with said fixed contact 102 in sliding each other by downward displacement 
of the movable contact 112 together with the movable contact plate 111 
because the armature 109 is attracted in the direction of the coil 107 
against the elasticity of the tension spring 110 and moves rotatively 
round the one end of the L-shaped plate 108 in the anticlockwise 
direction. And, when the movable contact 112 returns to the fixed contact 
101 on the left side between the respective fixed contacts 101 and 102 
shown in FIG. 5, said movable contact 112 comes in contact with said fixed 
contact 101 in sliding each other by upward displacement of the movable 
contact 112 together with the movable contact plate 111 because the arm 
armature 109 returns in the opposite direction of the coil 107 by the 
elasticity of the tension spring 110 and moves rotatively round the one 
end of the L-shaped plate 108 in the clockwise direction. In this manner, 
said movable contact 112 is so structured as to contact with respective 
fixed contacts 101 and 102 in sliding each other in order to wipe dust or 
the like off the contacts and to reduce contact resistance between the 
contacts (the contact of this kind is called a sliding contact, a wiping 
contact or a self-cleaning contact). 
However, in the above mentioned electromagnetic relay 100, because the 
armature 109 is designed so as to move rotatively in the clockwise or the 
anticlockwise direction round the one end of the L-shaped plate 108 by the 
elasticity of the tension spring 110 through said plate 108 in order to 
contact the movable contact 112 slidingly with the respective fixed 
contacts 101 and 102, the L-shaped plate 108 and the tension spring 110 
are required for moving the armature 109 rotatively, therefore there is a 
problem since increase of the parts in number prevents to reduce the cost. 
And, the armature 109 is desingned so as to move rotatively round the one 
end of the L-shaped plate 108 engaged to the projection 106a at the state 
in which the armature 109 is separated from the end 106b of the frame 106 
by said L-shaped plate 108, therefore there is another problem in that 
attractive force of the coil 107 for the armature 109 is lost remarkably 
by the gap existing between the armature 109 and the frame 106. 
SUMMARY OF THE INVENTION 
The present invention is made in view of the aforementioned problems of the 
prior art and an object of the invention is to provide an electromagnetic 
relay which has a movable contact and a fixed contact possible to contact 
slidingly with each other (that is the so-called sliding contact) in spite 
of simple structure, and is profitable in respect of the cost and possible 
to use the attractive force of the coil effecftively. 
The construction of the electromagnetic relay according to this invention 
for attaining the abovementioned object is characterized by having a fixed 
contact provided on a terminal fastened a base, a movable contact attached 
to a movable contact plate and for contacting and discontacting with the 
said fixed contact, an armature provided with the said movable contact 
plate, a core attached to a frame fixed to the base for attracting said 
armature and making the movable contact into touch with the fixed contact 
by excitation of a coil, and the said movable contact being sloped at a 
prescribed angle to an attracted face of said armature and said fixed 
contact being sloped at a prescribed angle to an attracting face of the 
said core. 
In the electromagnetic relay according to this invention, the fixed contact 
is sloped relative to the attracting face of the core and the movable 
contact is sloped relative to the attracted face of the armature at a 
prescribed angle respectively, therefore the electromagnetic relay 
according to this invention is structured so that the movable and the 
fixed contacts may contact slidingly with each other even when the 
armature is attached so as to contact with the frame and movably round the 
upper end thereof without using the L-shaped plate and the tension spring. 
Accordingly, the cost of said relay decreases and the attractive force 
loss of the coil also decreases.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
An embodiment of the electromagnetic relay according to this invention will 
be described below on basis of FIG. 1 and FIG. 2. 
An electromagnetic relay 1 shown in the figures is fixed to a base 2 with 
terminals 5 and 6 provided with fixed contacts 3 and 4 respectively, with 
a frame 8 attached with a core P of coil 7. An armature 9 is connected 
rotatably to the frame 8 by an resilient member 10 in the contacted state. 
The armature 9 is attached with a movable contact plate 12 (which forms a 
part of said resilent member 10 in this embodiment) provided with a 
movable contact 11 for contacting with and discontacting from said fixed 
contacts 3 and 4, and a terminal 13 connected with said movable contact 
plate 12 is fixed to the base 2. Either and of a wound wire 7a of the coil 
7 is connected to terminals 14 end 15 fixed to the base 2 respectively, 
The terminals 5 and 6 are fixed to the base 2 at the respective fixed parts 
5a and 6a provided in the center thereof in FIG. 1, and the parts lower 
than said fixed parts 5a and 6a of respective terminals 5 and 6 protrude 
downward in FIG. 1 in order to connect to the outside. 
And said terminals 5 and 6 are provided with fixed contact-attaching parts 
5b and 6b bent slightly in the leftward direction on the upper side of 
respective fixed parts 5a and 6a in FIG. 1, said fixed contact-attaching 
parts 5b and 6b are provided with fixed contacts 3 and 4 at the positions 
facing each other. 
The coil 7 is attached to the frame 8 for forming a magnetic path at a part 
of the core P thereof, and either end of a wire 7a wound around a bobbin 
7b is connected to the terminals 14 and 15 respectively. 
Said terminals 14 and 15 are also connected with a resistor R for 
eliminating a noise at the respective connected parts with said wound wire 
7a, the coil 7 is excited by supplying a prescribed current to the coil 7 
through the terminals 14 and 15. 
On the one side, frame 8 is fixed to the base 2 at an attached part 8b on 
the lower side of a frame body 8a having an inverted L-shaped section in 
FIG. 1. Said frame 8 is provided with a beam-shaped supporting part 8c for 
suspending the armature 9 so as to contact with said armature 9 (which 
will be explained later) at the left end thereof, and with a resilent 
member-fixing part 8d for fixing a frame-side portion 10b of the resilient 
member (which will be explained later) on the right side of said 
supporting part 8c in FIG. 1. 
On the other side, the armature 9 has a contacting part 9b suspended by the 
supporting part 8c of the upper end of the frame body 8a so as to contact 
with said supporting part 8c, and is attached with the resilient member 10 
by fixing a movable contact-side portion 10a of said resilient member 10 
to resilient member-fixing part 9d profided on the right side wall 9c of 
an armature body 9a in FIG. 1. 
Additionally, the resilient member 10 is a plate which has a inverted 
L-shaped section and some elasticity, and is formed in one united body 
from the movable contact-side portion 10a used as the movable contact 
plate 12 provided with the movable contact 11 and the frame-side portion 
10b fixed to the frame 8 in this embodiment. 
Said elastic member 10 is attached to the resilent member-fixing part 8d 
provided to the frame 8 at a fitting part 10c in the position near to 
right end of the frame-side portion 10b extending rightward in FIG. 1, and 
attached to the resilent member-fixing part 9d provided to said armature 9 
at a fitting part 10d in the center of the movable contact-side portion 
10a extending downward in FIG. 1. 
And, the resilient member 10 is provided with the movable contact 11 in the 
poition near to the lower end of the movable contact-side portion 10a in 
FIG. 1 between said fixed contacts 3 and 4, and a movable 
contact-attaching part 10e of the movable contact-side portion 10a is bent 
slightly in the rightward direction in FIG. 1. 
Namely, at the state in which the coil 7 is not excited as shown in FIG. 1, 
the armature 9 is energized in the clockwise direction in FIG. 1 at the 
state of contacting the contacting part 9b thereof with the supporting 
part 8c provided with the frame 8 by the resilient member 10. And the 
movable contact 11 provided to the movable contact-side portion 10a is in 
contact with the fixed contact 3 between the respective fixed contacts 3 
and 4, so that the terminal 13 and the terminal 5 are connected 
electrically with each other. 
Hereupon, as shown in FIG. 2, an extension line A extending toward the 
respective terminals 5 and 6 from the armature 9 intersects an extension 
line B extending toward the armature 9 from the fixed contact-attaching 
parts 5b and 6b of the respective terminals 5 and 6 and an extension line 
C extending toward the armature 9 from the movable contact-attaching part 
10e on the movable contact-side portion 10a (movable contact plate 12) of 
the resilient member 10 at the prescribed angle. Therefore, the fixed 
contacts 3 and 4 are sloped relative to the attracting face of the core P, 
and the movable contact 11 is sloped relative to the attracted face of the 
armature 9. 
At the state in which the coil 7 shown in FIG. 1 is not excited, by 
changing the switch (not shown) and supplying a prescribed electric 
current to the coil 7 through the terminals 14 and 15, magnetic flux is 
generated by excitation of the coil 7 and the armature 9 is attracted 
rightward in FIG. 1. 
By the attraction of the armature 9, said armature 9 moves rotatively in 
the anticlockwise direction in FIG. 1 against the elasticity of the 
resilient member 10 at the state in which the armature 9 is supported by 
the supporting part 8c provided to the frame 8 at the contact part 9b, the 
movable contact 11 provided to the movable contact-side portion 10a 
(movable contact plate 12) of the resilent member 10 discontacts from the 
fixed contact 3 between the respective fixed contacts 3 and 4 and contacts 
with the another fixed contact 4 slidingly each other, so that the movable 
contact 11 is maintained in the state as shown in FIG. 2. 
Thereby, the electrical connection between the terminal 13 connected to the 
movable contact 11 and the terminal 5 connected to the fixed contact 3 is 
intercepted and said terminal 13 and the terminal 6 connected to another 
fixed contact 4 are connected electrically. 
And, in this state, intercepting the power supply to the coil 7 through the 
terminals 14 and 15 by changing the switch (not shown), the coil 7 becomes 
into unexcited state and discontinues to attract the armature 9. Thereby, 
the armature 9 returns rotatively in the clockwise direction in FIG. 1 by 
the elasticity of the resileient member 10, the movable contact 11 
discontacts from the fixed contact 4 and contacts with the fixed contact 3 
slidingly each other, so that said movable contact 11 returns into the 
state as shown in FIG. 1. 
That is, movable contact 11 contacts with the fixed contact slidingly each 
other fulfills the function as the so-called sliding contact in the case 
the movable contact 11 separates from the fixed contact 3 on one side and 
comes in contact with the fixed contact 4 on the other side, and also in 
the case the movable contact 11 separates from the fixed contact 4 on the 
other side and comes in contact with the fixed contact 3 on one side. 
FIG. 3 and FIG. 4 show the electromagnetic relay according to another 
embodiment of this invention. 
The electromagnetic relay 1 in this embodiment is provided with flat-shaped 
fixed contact-attaching parts 5b and 6b on the upper side of fixed parts 
5a and 6a of respective terminals 5 and 6, and said respective fixed 
contact-attaching parts 5b and 6b are provided with fixed contacts 3 and 4 
so as to face each other. 
The frame 8 is bent rightward at the upper side of the attached part 8b 
thereof in FIG. 3, and has the same structure as that of the frame 8 shown 
in FIG. 1 and FIG. 2 except above. 
And also in case of this embodiment, as shown in FIG. 4, the extension line 
A extending toward the respective terminals 5 and 6 from the armature 9 
intersects the extension line B extending toward the armature 9 from the 
fixed contact-attaching parts 5b and 6b of the respective terminals 5 and 
6 and an extension line C extending toward the armature 9 from the movable 
contact-attaching part 10e on the movable contact-side portion 10a 
(movable contact plate 12) of the resilent member 10 respectively at the 
prescribed angle. Therefore, the fixed contacts 3 and 4 are sloped 
relative to the attracting face of the core P, and the movable contact 11 
is sloped relative to the attracted face of the armature 9. 
Thereby, said movable contact 11, in the same manner as that shown in FIG. 
1 and FIG. 2, contacts with the fixed contact slidingly each other and 
fulfills the function as the so-called sliding contact in the case the 
movable contact 11 separates from the fixed contact 3 on one side and 
comes in contact with the fixed contact 4 on the other side, and also in 
the case the movable contact 11 separates from the fixed contact 4 on the 
other side and comes in contact with the fixed contact 3 on one side. 
As described above, the electromagnetic relay according to this invention 
is provided with a movable contact sloped at a prescribed angle relative 
to an attracted face of an armature and a fixed contact sloped at a 
prescribed angle relative to an attracting face of a core. Therefore, it 
is possible to contact the movable and the fixed contacts slidingly each 
other even when the armature is attached to the frame so as to be in 
contact with the frame end and to move rotatively round the upper end 
thereof without using the L-shaped plate and the tension spring, so that 
excellent effects are obtained since it is possible to decrease the 
manufacturing cost and the loss of the attractive force of the coil at the 
time of the excitation.