JPH0721791Y2 - Latch mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to a latch mechanism for fixing a door body that is openably and closably attached to a casing of a copying machine, a facsimile machine or the like in a closed state.

2. Description of the Related Art In recent years, copiers and facsimile machines have become widespread and expanded, and are widely used as general office machines. In such copiers and facsimile machines, the internal cleaning,
Generally, an openable and closable door is provided in the housing to handle troubles when a paper jam occurs or to replace consumable parts, and the above process can be easily performed by opening the door. .

Taking a facsimile machine as an example, one of a pair of rollers that presses each other for conveying paper, or one of a roller and a belt that press each other is provided on the apparatus main body side, and the other is provided on the door body side, and the door body is opened The pressure contact of the rollers and the like is released at the same time so that the jammed paper can be easily removed. In the apparatus having such a configuration, a latch mechanism is used in order to prevent the door body from opening during normal operation or to maintain the pressure contact state of the rollers and the like appropriately.

In the conventional latch mechanism, as shown in FIG. 4, the latch pawls 21 and 22 having the tips 21a and 22a formed obliquely and the recesses 21b and 22b formed on the sides are provided at both ends of the shaft member 23. The shaft member 23 is rotatably attached to the end of the door body 24 opposite to the center of rotation, and is pinned to a position corresponding to the pair of latch claws 21 and 22 of the casing (not shown). Members 25 and 26 are provided respectively. The latch pawls 21 and 22 are biased by a coil spring or the like, and when the door body 24 is closed, the latch pawl 2
The slanted portions 21a and 22a of the first and the second 22 contact the pin members 25 and 26, and the slanted portions 21a and 22a are pushed by the pin members 25 and 26, and the latch claws 2
After the members 1 and 22 rotate against the biasing force of the coil spring or the like, the pin members 25 and 26 engage with the recesses 21b and 22b of the latch claws 21 and 22 to fix the door body 24 to the housing. It is like this.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-described latch mechanism, when fixing the door body to the housing, the door body is closed and then the side of the door body where the latch claws are provided is pressed toward the housing side. Thus, the latch claw and the pin member are engaged with each other. But,
By pressing the vicinity of the center of the door body on the side of the latch claws (the position in FIG. 4), both latch claws engage with their respective pin members and a good locked state can be obtained. When the vicinity of (for example, the position in FIG. 4) is pressed, the door body bends as shown by the dotted line in FIG. 4, and as shown in FIG. The latch claw (latch claw on the side closer to the portion that pressed the door body) 21 engages with the pin member 25, while the other latch claw 22 has the inclined portion 22.
a remains in contact with the pin member 26, and the latch claw 2
The second recess 22b may not engage with the pin member 26. Hereinafter, a state in which the concave portion of the latch claw and the pin member are engaged is referred to as a latch state, and a state in which only one of the pair of latch claws is in the latch state is referred to as a one-latch state.

Generally, when both of the latch claws are not in the latched state, the sensor or the like detects that the door is not closed, and the device cannot be operated.
In the one-sided latched state, such a detection may not be performed, and in this case, the pressure contact state of the sheet conveying roller or the like becomes improper, which may cause a sheet skew or a sheet jam. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a latch mechanism that does not have a one-side latch state.

Means for Solving the Problems A door is rotatably provided in a housing, and a pair of latch claws that can be integrally rotated with each other are provided in the vicinity of both side portions on the side opposite to the center of rotation of the door. Alternatively, the pair of pin members, which are arranged on one of the door bodies and which engage with the pair of latch claws, are arranged on the other side of the housing or the door body. Each of the latch claws has a first sliding portion substantially parallel to the rotation radius direction, a concave portion on the rotation center side of the first sliding portion, and a first slide portion on the side opposite to the rotation center. A second sliding portion formed obliquely with respect to the moving portion, and when the door is closed, the latch claw is moved to the second sliding portion and the first sliding portion by the pin member. The pin member is engaged with the concave portion to fix the door body after rotating the door body. Then, in order to fix the door body in the closed state, a pair of latch claws or a pair of pin members of the door body when pressing the vicinity of one end on the side opposite to the rotation center of the door body The length of the straight portion of the latch pawl is set to be longer than the maximum amount of bending between the arranged portions.

According to the latch mechanism of the present invention, the length of the first sliding portion of the latch claw is provided with the latch claw or pin member of the door body when the door body is pressed to close the door body. It is longer than the maximum bending amount between the parts. As a result, when the pin member can be engaged with the recess of one latch pawl but the pin member is not engageable with the recess of the other latch pawl, the other latch pawl first The pin member is in contact with the one sliding portion. In this state, the other latch claw is rotated by the pin member, and the respective latch claws rotate integrally, so that the one latch The pawl cannot also engage the pin member. In this way, unless both latch claws are pressed to the position where they can be engaged with the pin member, both latch claws will not be in the latched state.
As a result, the one-latch state does not occur, and the trouble caused by the one-latch state can be eliminated.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a part of a facsimile machine or the like which employs a latch mechanism according to the present invention. A door 2 is rotatably supported on the top of the housing 1. Although not shown, a thermal head for recording and other means necessary for recording are housed inside the housing 1. Reference numerals 3 and 4 denote drive rollers that are rotationally driven by drive means (not shown), and support shafts 5 and 6 of the drive rollers 3 and 4 are support members attached to the housing 1.
Backed by 7,8. Reference numerals 9 and 10 denote pinch rollers provided so as to come into pressure contact with the drive rollers 3 and 4.
A support member 11 is rotatably supported by a support member 11, and the support member 11 is attached to the lower surface of the door body 2 via spring members 12 and 12.

A pair of latch claws 13 (13 ') are provided on both ends of the door body 2 on the side opposite to the center of rotation, and a pin member 14 (14') is provided on the housing 1 correspondingly. There is. Latch claw 13 (1
3 ') are integrally fixed to both ends of a shaft member 16 rotatably supported by a support member 15 fixed to the door body 2, and the stopper 17 restricts the clockwise rotation. It is biased clockwise by the coil spring 18. As shown in FIG. 2, the latch claw 13 (13 ') has a first sliding portion which is substantially parallel to the radial direction A of rotation thereof.
13a (13a '), a recess 13b (13b') on the shaft member 16 side of the first one sliding portion 13a (13a '), and a first sliding portion on the end opposite to the shaft member 16 The second sliding portion 13c (13c ') is formed obliquely with respect to 13a (13a'). Latch nail
The length z of the first sliding portion 13a (13a ') of 13 (13') is one of the sides on which the latch claws 13 (13 ') of the door body 2 for closing the door body 2 are arranged. It is set so as to be larger than the maximum amount of bending between the portions where the latch claws 13 (13 ') of the door body 2 are pressed when the vicinity of the end portion is pressed.

As shown in FIG.
The state of the latch pawls 13,13 'is shown when the ends of the door body 2 are pressed to engage the 4,14'. According to this embodiment, the length z of the first sliding portions 13a, 13a 'of the latch claws 13, 13' is such that the door body 2 is latched when the door body 2 is pressed to close the door body 2. It is set to be longer than the maximum deflection amount y between the portions where the claws 13 and 13 'are arranged. As a result, for example, when one end of the door body 2 on the side where the latch claws 13 and 13 'are provided is pressed, the concave portion of the one latch claw (the front latch claw in FIG. 3) 13 is pressed. Even when the pin member 14 can be engaged with the first sliding portion 13 of the other latch claw 13 '.
The a'is in contact with the pin member 14 'at a position (z-y) lower than the recess 13b', and in this state, the other latch claw 13 'is moved by the angle α ° by the pin member 14'. It is rotated and each latch claw 13, 13 'is
Since it rotates integrally by 6, one of the latch claws 13 cannot also engage with the pin member 14. In this way, unless both latch claws 13 and 13 'are pressed to the positions where they can be engaged with the pin members 14 and 14', respectively, the latched state will not occur, so that it is not possible to operate in the one latched state, It is possible to prevent skewing of the paper and jamming of paper due to no recording being performed in a state where the pressure contact between the drive rollers 3 and 4 and the pinch rollers 9 and 10 is not appropriate.

In the device implemented by the present inventors, y = 8
Good results have been obtained by setting z = 15 to 25 mm for ~ 12 mm. Further, in this embodiment, the latch claw is provided on the door body,
Although the pin member is provided in the housing, the latch claw may be provided in the housing and the pin member may be provided in the door body.

Effect of the Invention Since the present invention is configured as described above in detail, the latched state cannot be obtained unless both the latch claws can be engaged with the pin member, and there is no one-latch state. Therefore, it is possible to eliminate the trouble caused by the one-latch state.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of an embodiment of the present invention, FIG. 2 is a view showing the shape of the latch pawl, FIG. 3 is a perspective view for explaining the movement of the latch pawl, and FIG. FIG. 5 is a perspective view for explaining the conventional technique, and FIG. 5 is a perspective view for explaining the problems of the conventional technique. 1 ... Case, 2 ... Door, 13,13 '... Latch claw, 13a, 1
3a '... first sliding portion, 13b, 13b' ... recessed portion, 13c, 13c '
...... Second sliding part, 14,14 '…… Pin member, 16 …… Shaft member.

Claims (1)

[Scope of utility model registration request] 1. A door body is provided rotatably in a housing, and a pair of latch claws that can integrally rotate with each other are provided in the vicinity of both ends of the door body opposite to a center of rotation of the door body. A pair of pin members that engage with the pair of latch claws are disposed on the other side of the housing or the door body while being disposed on one side of the body,
Furthermore, each latch claw has a first
Of the sliding part and the first sliding part on the side of the rotation center of the first sliding part, and the second sliding part formed on the side opposite to the center of rotation and obliquely to the first sliding part. And the pin member engages with the recess after the latch pawl is rotated by the pin member along the second sliding part and the first sliding part when the door is closed. In the latch mechanism adapted to fix the door body in combination, in order to fix the door body in a closed state, the latch mechanism is used when the vicinity of one end of the door body opposite to the rotation center is pressed. A latch mechanism, wherein the length of the first sliding portion of the latch pawl is made longer than the maximum amount of bending between the portions of the door body where the pair of latch pawls or the pair of pin members are arranged.