JPS6237045Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a door latch device for a microwave oven.

Conventionally, a structure is known in which a plurality of door latches that lock the door are released at once by pulling a door release lever disposed along the front surface of the door of a microwave oven toward the front of the door.

In a door latch device having such a structure, firstly, all door latches must operate uniformly no matter which part of the door opening lever is applied with pulling force, and secondly, the movement of each door latch must be controlled. Thirdly, the mechanism that transmits the movement of the door release lever to multiple door latches must operate smoothly without any squeaks or rattles, or such smooth operation. It must be of a structure that allows for easy assembly. However, conventional devices of this type are not necessarily satisfactory in the above points.

In view of this technical background, the present invention provides an improved door latch device.

FIG. 1 shows a microwave oven equipped with an embodiment of this invention. This microwave oven has a high-frequency heating chamber built into its main body 1, and the front opening of the high-frequency heating chamber is opened and closed by a door 2.
In addition, a door release lever 4 (described later) is arranged inside the door handle 3 of the door 2, and the door release lever 4 is operated to operate door latches 5, 6, which will be described later, to release the door from the locking parts 7, 8 of the main body. When the lock is released, a plurality of door switches 9 and 10 are opened and closed to switch the microwave oven circuit to a desired mode.

FIGS. 2 and 3 show an embodiment of this invention installed in this type of microwave oven.

Reference numerals 11 and 12 indicate mounting fittings welded to the outer frame 13 of the microwave oven door 2. The door latches 5, 6 are attached to the mounting brackets 11, 12 at their pivot points 1.
4 and 15 so as to be rotatable, and the base ends 5a and 6a thereof are engaged with the door frame 13 and stopped. 16 is the pivot pin 17,
An interlocking lever 18 engages with each of the door latches 5 and 6 to interlock the door latches 5 and 6, and an interlocking lever 19 engages with the door frame 1 at one end thereof.
3 and the door latch 6 at its other end, the spring biases the door latches 5 and 6 in the locking direction via the door latch 6 and the interlocking lever 16.

The door latches 5, 6 are formed with protruding pieces 5b, 6b, and contact portions 5'b, 5'b, 6b of the protruding pieces 5b, 6b,
A lock release force is applied at 6'b. The door release lever 4 is arranged along the front surface of the door in a recess 20 inside the door handle 3, and is drawn toward the door handle 3 in a manner substantially parallel to and opposed to the door handle 3 using the wall of the recess 20 as a guide.

Reference numeral 21 denotes an intermediary mechanism disposed between the door release lever 4 and the door latches 5, 6, which moves integrally with the door release lever 4 and connects the plurality of door latches 5, 6.
6 to release and bias the door latches 5 and 6. The intermediary mechanism 21 includes lever shafts 22 and 23 made of synthetic resin that fit onto both ends of the door release lever 4 and extend toward the rear of the door through the door frame 13, and are secured by nuts 24 and 25 at both ends thereof. It is formed of a plate-shaped driven lever 26 that faces the door opening lever 4 in parallel and moves in the plane direction thereof.

The plate-shaped driven lever 26 has approximately the same length as the door release lever 4, and the lever shaft 2 is connected to the lever shaft 2 at both ends thereof.
2 and 23, and screw nuts 24 and 25 onto the lever shafts 22 and 23 from the back side of the driven lever 26, so that the positions of the lever shafts 22 and 23 are regulated by the nuts 24 and 25 on the back side, and the front side thereof. The position of the door latches 5 and 6 is regulated by the protruding pieces 5b and 6b of the door latches 5 and 6. Here, when the door release lever 4 is pulled forward, the nuts 24 and 25 are integrally connected to the door release lever 4 via the lever shafts 22 and 23.
also moves forward, and these nuts 24, 25
In conjunction with this, the driven lever 26 follows and moves forward substantially parallel to the door opening lever 4.

In the above device, when the door release lever 4 is pulled toward the front of the door, the two door latches 5 and 6 rotate and are disengaged from the locking portions 7 and 8, respectively. The movement of the door latches 5 and 6 is transmitted to the driven lever 26, and further transmitted from the driven lever 26 to the respective door latches 5 and 6 via the same mechanism including the protruding pieces 5b and 6b, and the mutual movement of the door latches 5 and 6 is transmitted to the driven lever 26. 16
Therefore, all the door latches operate almost uniformly even if a pulling force is applied to any part of the door release lever 4. Further, the driven lever 26 cooperates with the nuts 24, 25 and contacts the protruding pieces 5b, 6b of the door latches 5, 6. Therefore, when the door release lever 4 is pulled toward the front of the door, the driven lever 26 protrudes accordingly. Push pieces 5b and 6b towards the front of the door,
As a result, the door latches 5 and 6 are placed at pivot points 14 and 15.
Rotate counterclockwise around , and release the lock from the locking parts 7 and 8. The door release lever 4 is normally in contact with the outer frame 13 of the door 2 as shown in FIG.
The screwing position of the nuts 24 and 23 can be adjusted in the front-rear direction, that is, the distance of the nuts 24 and 25 from the outer frame 13 is adjusted while both ends of the door release lever 4 are in contact with the outer frame 13. Thereby, since the driven lever 26 cooperates with the nuts 24 and 25, the distance from the outer frame 13 is similarly adjusted. Here,
When the nuts 24 and 25 are adjusted to a position close to the outer frame 13 and the driven lever 26 is similarly adjusted to a position close to the outer frame 13, the driven lever 26 pushes the protruding pieces 5b and 6b toward the front of the door and locks the door latch. 5,
6 is in a locked position in which it is rotated slightly counterclockwise compared to the normal state when it is locked in the locking portions 7 and 8. Conversely, when the driven lever 26 is adjusted to a position far from the outer frame 13, the protruding pieces 5b, 6b are less pressed forward by the driven lever 26, and the door latches 5, 6 are moved slightly clockwise compared to the above position. It is in the rotated lock position. The clockwise rotation is possible until the base ends 5a, 6a of the door latches 5, 6 come into contact with the door frame 13 and are stopped. Therefore, the movement of the door latches 5, 6 is caused by the movement of the proximal ends 5a, 6.
As long as a does not touch the door frame 13, nut 2
By adjusting 4 and 25 back and forth, the lock position can be easily changed and adjusted. Therefore, when the door release lever 4 is pulled, the point at which the door latches 5, 6 are unlocked from the locking portions 7, 8, or the point at which each switch 9, 10 is turned off by the door latches 5, 6 is subject to assembly errors. Even if there is an undesired deviation from the position, this deviation can be easily corrected by adjusting the nuts 24, 25 back and forth as described above. Furthermore, since the driven lever 26 and each door latch 5, 6 are simply in contact with each other, the movement of the driven lever is smoothly transmitted to each door latch even if there is no precision in the arrangement between them, so that the door can be opened. No matter which part of the lever 4 is pulled, the movement is evenly and smoothly transmitted to each door latch. Also, I have never experienced a situation where the assembly accuracy deteriorates and the device becomes difficult to move during use. On the other hand, as shown in FIG.
The protruding pieces 5b, 6b extend from the door latches 5, 6 to beyond the straight line 27 connecting the lever shafts 22, 23, and in this case, the protruding pieces 5b, 6b extend across the entire width along the front surface of the driven lever 26. Therefore, the contact surfaces 5b', 6b' of the protruding pieces 5b, 6b with the driven lever 26 are aligned with the straight line 27 connecting the lever shafts 22, 23.
pass above. As shown in FIG. 4, if the contact surfaces 28 and 29 are off the straight line 30, there is a risk that the driven lever 26 will be pressed by the protruding pieces 5b and 6b and rotate around the straight line 30. . In contrast, in this embodiment, the contact surface portion 5'
b and 6'b pass along the straight line 27, so that the driven lever 26 does not rotate undesirably, and therefore, the movement of the door opening lever 4 is ensured without loss of the amount of movement of the driven lever 26. Door latch 5,6
can be conveyed to.

As is clear from the above explanation, according to the present invention, all the door latches operate uniformly no matter which part of the door opening lever is applied the pulling force, and the movement of each door latch can be easily adjusted during assembly. Furthermore, the mechanism for transmitting the movement of the door opening lever to the plurality of door latches operates smoothly without creaks or rattles, or can be easily assembled to ensure such smooth operation.

[Brief explanation of the drawing]

Fig. 1 is a front view of a microwave oven equipped with an embodiment of this invention, Fig. 2 is a partially sectional front view of an embodiment of this invention, and Fig. 3 is a side view of the same embodiment. , FIG. 4 is a side view of a comparative example to one embodiment of this invention. 2... Microwave oven door, 4... Door release lever, 5, 6... Door latch, 16... Interlocking lever, 19... Spring, 22, 23... Lever shaft, 24, 25... Nut, 26... Follower Lever, 5b, 6b... protruding piece.

Claims (1)

[Scope of utility model registration request] a door release lever arranged along the front surface of the door of the microwave oven and capable of being pulled toward the front of the door; a plurality of door latches rotatably supported on the door;
An interlocking lever that engages with each of the door latches to interlock the door latches, a spring for biasing the door latch in the locking direction, a driven lever having approximately the same length as the door opening lever, and both ends of the door opening lever. A lever shaft is fixed to each of the lever shafts and extends to the rear of the door, and with both ends of the driven lever inserted through each of the lever shafts, the lever shaft is adjustable and screwed to each of the lever shafts, and A nut is formed on each of the door latches, and extends from each of the door latches to a point beyond a line connecting the lever axes, for causing the driven lever to follow the door release lever when the lever is pulled toward the door. A door latch device for a microwave oven, comprising a protruding piece that contacts the front surface of the following movement side of the lever and converts the following movement into a releasing operation of each of the door latches.