JPH0121574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch device using a toggle mechanism.

Generally, a switch using a toggle mechanism opens and closes by bringing a pair of contacts into contact and separating with a constant contact pressure, but in the process from ON to OFF, the contact pressure gradually decreases and reaches the zero point.
In this process, when the contact pressure is around zero, it becomes extremely unstable.
It has the disadvantage that the arc causes electrolytic corrosion and chattering.

The object of the present invention is to provide a switch device that can eliminate the above-mentioned drawbacks.

The present invention includes a drive arm that rotates around an axis in response to a bimetal, and a reversing plate that is held by a holding portion formed on the drive arm and is provided with a toggle spring that is engaged so that the reversible plate can be freely reversed. ,
It consists of an insulator fixed to the free end side of the reversing plate and a pair of contact plates facing each other, and at least one of the pair of contact plates is biased in a direction perpendicular to the direction of operation of the insulator. The insulator is elastically biased in a direction in which the contacts are brought into contact with each other, and the insulator is inserted into and removed from between the contact plates by a toggle action of the reversing plate, thereby bringing the contacts into and out of contact. It is. In other words, by making the insulator protrude between the contact plates that are in elastic contact and separating the contact plates, the insulator is evacuated from between the contact plates.
It turns ON and OFF, but since the insulator is held by a toggle mechanism that quickly reverses, the speed between the contact plates is extremely fast.Furthermore, since the contact plates face each other with the insulator in between, the insulator is retracted. At the moment the insulator protrudes, it contacts the insulator at high speed without any delay factor, and at the moment the insulator protrudes, it separates at high speed without causing any delay factor to its own elasticity.
Therefore, the structure is such that electrolytic corrosion due to chattering and arcing can be prevented and durability can be improved.

An embodiment of the present invention will be described based on drawings of a toaster. Although only one side is shown, 1 is a main frame that partitions both ends of the bread roasting chamber, and this main frame 1 has a lifting shaft 2.
is provided. A lifting platform 4 connected to a bread pedestal 3 provided in the bread roasting chamber is provided on the lifting shaft 2 so as to be able to move up and down while being biased upward by a spring 5. Further, the main frame 1 is provided with a locking mechanism 6 for locking the lifting platform 4 in a lowered state. That is, this lock mechanism 6 includes a foot lever 9 that interferes with the lowering movement of the lifting table 4 and rotates clockwise while pulling the spring 7 and engages with a locking hole 8 formed in the side surface of the lifting table 4. , a lock lever 1 which is rotatably held while being biased counterclockwise by a spring 10 and engages with one end of the foot lever 9;
1 and more. Further, a switch stand 12 is fixed to the main frame 1, and an actuator 1 that is pressed by the pressing piece 13 of the lift stand 4 is mounted on the switch stand 12.
4 and a bimetallic power switch 16
A bimetal switch 17, which is a switch, is provided. This bimetal switch 17 is a switch using a toggle mechanism. That is, the switch stand 12 has a U-shaped base 18 at one end.
A drive arm 20a having an adjusting screw 19 screwed onto the other end thereof is rotatably held on a shaft 22 while being biased clockwise by a spring 21. The free end edge of this base 18 holds one edge of the reversing plate 23.
A letter-shaped holding portion 24 is formed. The other end of a toggle spring 25, one end of which is held by the shaft 22, is fixed to the reversing plate 23, and an insulator 27 having a conical inclined portion 26 at the top thereof is fixed to the tip. The drive arm 20a, the reversing plate 23, and the tension spring 25 form a toggle mechanism 20. A fixed contact plate 28 and a movable contact plate 29, which are contact plates facing each other with this insulator 27 in between, are fixed to the side surface of the switch base 12 with screws 31 with an insulator 30 interposed on the base side thereof. ing. One movable contact plate 29 is biased in the contact contact direction by forming a U-shaped bending portion 32 in its intermediate portion. Further, an inclined surface 33 corresponding to the inclined portion 26 of the insulator 27 is formed at one end of the movable contact plate 29. These contact plates 28 and 29 have contact points 28 facing each other between the inclined surface 33 and the bending portion 32.
a, 29a are fixed. Further, stoppers 34 and 35 are formed on the switch base 12 and face each other with the reversing plate 23 in between.

Next, a support shaft 36 is erected at the lower left side of the main frame 1, and a release rod 38 is held on the support shaft 36 and a support portion 37 provided at the upper part of the main frame 1 so as to be vertically movable. There is. An adjustment screw 39 is screwed into the lower end of the release lever 38 to flip up the tip of the lock lever 11 extending downward to the left.
A pin 40 located at the upper part of the pin 40 is erected, and sawtooth locking portions 41 are formed on both sides. Further, a seesaw body 42 is rotatably held on the support shaft 36 while being biased counterclockwise by a torsion spring 43. This seesaw body 42 has the locking portion 4
A feed pawl 44 that elastically engages with 1 is held. These feed claws 44 are formed with projecting pieces 45 that extend rearward. A lever 46 connected to the lifting platform 4 is provided. This lever 46 comes into contact with the projecting piece 45 to separate the feed pawl 44 from the locking portion 41, and releases the feed pawl 44 to engage with the locking portion 41 when descending. Therefore, tapered inclined edges 47 are formed on both sides of the upper part of this lever 46. Furthermore, a plate 4 is provided on the support shaft 36 and the support portion 37 to prevent the pin 40 of the release rod 38 from falling.
8 is retained. (See Figure 1) Furthermore,
This support shaft 36 has a receiving piece 49 that extends further to the right than the receiving piece 49 that extends to the right of the seesaw body 42 and projects between the free end of the bimetal 16 and the adjustment screw 19 of the drive arm 20a. Operation expansion lever 5
0 is rotatably held. Furthermore, a knob 52 having a cam 51 that comes into contact with the pin 40 is attached to the support shaft 36 .

Next, a circuit diagram is shown in FIG. The bimetal 16 and the bimetal switch 17 are connected in parallel between the heater 53 provided in the bread roasting chamber and the power switch 15 connected to a power source 54.

In this configuration, the roasting time is set by turning the knob 52. That is, the cam 51 pushes up the pin 40 to arbitrarily set the distance between the left end of the lock lever 11 and the adjusting screw 39 of the release lever 38. Then, the lifting platform 4 is lowered together with the bread holder 3. As a result, the lever 46 also descends and its inclined edge 47 releases the feed pawl 44, so that the feed pawl 44 engages with the locking portion 41. On the other hand, the power switch 15 is turned on and the heater 53 is kept energized. Then, the bimetal 16 generates heat by itself and begins to curve, pressing the receiving piece 49 of the seesaw body 42 and the operation magnifying lever 50. As a result, the drive arm 20a rotates counterclockwise via the adjustment screw 19, and the V-shaped holding portion 24 crosses the line of action of the toggle spring 25, so that the reversing plate 23 is stored in the toggle spring 25. Due to the energy, the insulator 27 is reversed at a very high speed and the contact plate 2
Evacuate at high speed from between 8 and 29. This results in
The movable contact plate 29 momentarily contacts the fixed contact plate 28 due to the elasticity stored in the bending portion 32. That is, the bimetal switch 17 is turned on. The stroke of the reversing plate 23 at this time is the stopper 34.
limited by. As a result, bimetal 16
The energization to is cut off, and the bimetal 16 is eventually cooled by heat radiation and returns upward. Accordingly, the seesaw body 42 is urged by the torsion spring 43 to return, and the drive arm 20a is also returned clockwise by the force of the spring 21. As a result, the reversing plate 23 is reversed counterclockwise at high speed, and the insulator 27 is rotated against the contact plate 23.
It protrudes at high speed between 8 and 29. The movable contact plate 29 is separated from the fixed contact plate 28 and the bimetal switch 1
7 is turned off, and from this point on the bimetal 16 is energized. That is, the bimetal 16 repeats heating, cooling, and deforming operations to cause the seesaw body 42 to reciprocate. Each time, the release rod 38 is sent upward little by little by the feed pawl 44, and eventually the adjustment screw 3
Flip up the lock lever 11 with the tip of 9. As a result, the foot lever 9 is released and returns counterclockwise, and the lifting platform 4 is moved between the bread holder 3 and the lever 46.
rises with As the lever 46 rises, the feed pawl 44 is pushed outward, making it possible to adjust the set height of the release rod 38.

Regarding the operation of the bimetal switch 17, the insulator 27 is provided on the reversing plate 23, which reverses itself at a very high speed using the tension stored in the toggle spring 25 as energy.
The contact and separation operations of the contact plates 28 and 29 are performed instantaneously. That is, when ON, the movable contact plate 29 contacts the fixed contact plate 28 by its own elasticity without any delay factor being applied to the insulator 27, and when OFF, the movable contact plate 29 separates from the fixed contact plate 28 at the moment the insulator 27 protrudes. Therefore, the durability can be improved without causing chattering or electrolytic corrosion of the contacts due to arcing. Further, the bimetal 16 operates the drive arm 20a of the toggle mechanism 20, and the bimetal 16 is connected to the support shaft 36.
The distance from the support shaft 36 to the adjustment screw 19 is greater than the distance from the contact point with the operation enlargement lever 50.
Since the drive arm 20a is driven via the drive arm 20a, the strokes of the drive arm 20a and the reversing plate 23 are expanded. As a result, the tension of the toggle spring 25 that is stored when the vehicle is inverted and neutral is increased, and the contact switching is performed by the increased tension, so that the switching operation is even more reliable. In addition, since the contact plate 29 is biased by forming a U-shaped bending part 32 in its middle part, the spring constant is small and no large stress is generated, so that it can withstand long-term use. Can be done. Furthermore, since the upper portions of the contact plates 28 and 29 are covered by the switch base 12, they are always protected and do not deform during transportation or assembly. Although one of the contact plates 28 and 29 is fixed and the other is movable, both may be movable. Moreover, the bimetal switch 17 may be used for other than toasters.

As described above, this invention has an insulator mounted on a toggle mechanism that quickly reverses itself using energy stored in a toggle spring, so that the speed of ejection and retraction is extremely fast. By energizing and facing each other, when the insulator is retracted, it contacts the insulator at high speed without any delay factor, and the moment the insulator protrudes between the contact plates, it is delayed by its own elasticity. This has the effect of being able to separate at high speed without being affected by any factors, thereby preventing chattering and electrolytic corrosion due to arc, and improving durability.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a perspective view showing the mechanical part of the toaster, Fig. 2 is a front view showing the main part in a reduced scale, Fig. 3 is a front view showing the roasting state of the main part in a reduced scale, and Fig. 4 is a front view showing the main part in a reduced scale.
The figure is a partially enlarged front view showing the operation of the bimetal and bimetal switch, Fig. 5 is an enlarged exploded perspective view of the bimetal switch, Fig. 6 is its perspective view, Fig. 7 is its plan view, and Fig. 8 9 is an enlarged side view showing the relationship between the contact plate and the insulator, and FIG. 9 is a circuit diagram. 17...Bimetal switch (switch), 2
0...Toggle mechanism, 25...Toggle spring,
27... Insulator, 28... Fixed contact plate (contact plate),
29...Movable contact plate (contact plate).

Claims (1)

[Claims] 1. A drive arm that rotates around an axis in response to a bimetal, a reversing plate that is held by a holding part formed on the drive arm and is provided with a toggle spring that can be freely reversed, and this reversing plate. It consists of an insulator fixed to the free end side of the plate and a pair of opposing contact plates, and at least one of the pair of contact plates is offset in a direction perpendicular to the direction of operation of the insulator. A switch device characterized in that the contacts are elastically biased in a direction in which they come into contact with each other, and the insulator is inserted and removed between the contact plates by a toggle action of the reversing plate, thereby causing the contacts to connect and separate.