JPH0614236Y2 - Image forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a so-called sheloopun type image forming apparatus in which an upper part of a machine body rotates up and down, and more particularly, to a locking mechanism for locking an upper machine body to a lower machine body. It is a thing.

[Prior art]

In image forming apparatuses such as electrophotographic copying machines and electrophotographic printers, in order to facilitate maintenance, the apparatus main body is composed of an upper body and a lower body, and a shell open mechanism in which the upper body rotates up and down is adopted. Since the upper body is normally spring-biased in the opening direction, a locking mechanism is required for the lower body when the upper body is closed.

FIG. 7 shows a conventional locking mechanism, which is provided with a locking mechanism for an upper machine body that is movable in conjunction with a shell opening lever 1 provided at a location where an operator can easily operate. This locking mechanism is composed of a rotation shaft 3, locked members 4, 5, locking pieces 6, 7, etc., and the shell opening lever 1 is fixed to the rotation shaft 3 having a prism shape. The bearing 3 is rotatably supported by the bearing 8 with respect to the upper body. Further, locked members 4, 5 are fixed near both ends of the rotating shaft 3, and the shell opening lever 1, the rotating shaft 3, and the locked members 4, 5 are fixed.
Are integrally rotatable with each other in the B and B'directions. The rotating shaft 3 is constantly urged to rotate in the direction of arrow B by a spring (not shown), and the locked member 5 comes into contact with the pin 9a that is erected on the solid portion 9 of the upper machine body. The rotation stop position in the direction is regulated.

Further, hook-shaped hook portions 4a, 5 are provided at the tips of the locked members 4, 5, respectively.
a is formed, and the inclined surfaces 4b and 5 of the hook portions 4a and 5a are formed.
b is constructed smoothly.

On the other hand, the locking pieces 6 and 7 are fixedly attached to a frame (not shown) in the lower body, the tips of the locking pieces 6 and 7 are bent at a predetermined angle, and the inclined surfaces 6a and 7a thereof are smooth. It is configured. Further, locking holes 6b and 7b are provided below the above-mentioned inclined surfaces 6a and 7a of the locking pieces 6 and 7, respectively. When the upper body is rotated in the A'direction and the upper body is closed to the lower body, the hooks 4a, 5a of the locked members 4, 5 are formed.
And the locking holes 6b and 7b of the locking pieces 6 and 7 are locked.

[Problems of conventional technology]

Since the upper body of the image forming apparatus is not a completely rigid body, twisting may occur when the operator closes the upper body, and if such twisting occurs, it will be in a one-side locked state as shown in FIG. Sometimes. The one-locked state means that only one of the two locking mechanisms is locked and the other is unlocked. That is, the state shown in FIG.
While the tip of a is locked in the locking hole 7b, the hook portion 4a is stopped in front of the upper end of the locking hole 6b in the figure (A), and is in a non-locking state.

When the image forming operation is started in such a state that only one hook portion is locked, that is, in the one-locked state, the hook portion 5a is disengaged due to vibration, and the upper body of the image forming apparatus suddenly opens. There was a risk of being lost.

Further, even if the image forming operation can be performed without the upper machine body being opened, the nip force of the roll that conveys the paper is different between left and right,
Problems such as skew feed, paper jam, or unfixed on one side may occur.

[Purpose of device]

In view of the above-mentioned conventional drawbacks, the present invention provides an image forming apparatus having a locking mechanism capable of completely locking the upper body and the lower body when the shell is closed even if the upper body is slightly twisted. It is a thing.

[Key points of device]

In order to achieve the above-mentioned object, the present invention provides an upper body that can be opened and closed by rotating it about a lower body around a horizontal axis, and a biasing member that biases both bodies in an opening direction. In the image forming apparatus including a locking mechanism that locks in a closed position, the locking mechanism includes a plurality of first locking members provided on one of the two machine bodies and the other one of the two machine bodies. A first locked member that is movably supported in a predetermined direction that intersects with the rotation trajectory of the upper machine body and that is locked to each of the plurality of first locking members when the two machine bodies are closed; A second locking member provided on one side of the machine body and movable up and down, and a second locking member provided on the other side of the machine bodies, which is integrally movably connected in the predetermined direction, A second locked member that is locked by the second locking member, and when closing the two machine bodies, Note that the second locked member is locked to the first locked member by the contact between the second locked member and the second locked member. A predetermined position and a closing direction until the position exceeds a predetermined position, the second locked member locks the second locked member,
By biasing the upper body in the opening direction by the biasing member, the second locking member is moved upward, and the first locked member is locked by the first locking member. It is characterized by that.

[Example of device]

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 6 is a schematic sectional view of a liquid crystal printer which is an example of an image forming apparatus to which the locking mechanism of the present invention can be applied. The liquid crystal printer 10 is composed of an image forming section 11 and a sheet conveying section 12. The image forming unit 11 includes a photoconductor drum 13, a charger 14 arranged near the photoconductor drum 13, which uniformly applies electric charges to the surface 13a of the photoconductor drum 13, and a photosensitive member based on print data sent from an external device. A liquid crystal head 15 that forms an electrostatic latent image on the body drum 13, a developing device 16 that develops the electrostatic latent image with toner to visualize it, and the visualized toner image is conveyed by a sheet conveying mechanism described later. Coming paper P
And a cleaner 18 for cleaning the toner remaining on the photosensitive drum 13 without being transferred by the transfer device 17. Further, the paper transport unit 12
Is a paper feed roller 20 for feeding the paper P from the cassette 19, a guide plate 21 for guiding and conveying the paper fed by the paper feed roller 20, the paper P that has been fed once, and the photosensitive drum. A standby roll 22 that re-feeds the sheet P in time with the toner image on the sheet 13, and a front transport guide plate 23 that guides the sheet P transported by the standby roll 22.
And a rear transport guide plate 24, a fixing device 25 for fixing unfixed toner on the paper P by heat and pressure, and transport rolls 27, 2 for discharging the fixed paper onto a paper discharge tray 26.
It is composed of 8.

On the other hand, in the liquid crystal printer 10, the upper machine body 29 has a rotating shaft 31 in order to improve maintainability when a paper jam occurs.
It is configured so that it can be opened and closed by rotating around. Upper fuselage 2
9 and the lower body 30 can be opened in the direction of arrow A and can be closed in the direction of arrow A ′ with the two-dot chain line shown in the figure as a boundary. A force is always acting on the upper body 29 in the A direction, that is, the opening direction by a spring mechanism (not shown). Therefore, when the upper body 29 is closed, the upper body 29 is locked to the lower body 30 by the locking mechanism 2. Fig. 1 (A)
FIG. 3 is a perspective view showing the structure of the locking mechanism 2 of the present invention,
FIG. 2B is an explanatory diagram for explaining the shape of the limiting member 40, and FIGS. 2 to 5 are cross-sectional views of the main parts for explaining the operation. Each of FIGS. 2 to 5 (A) shows a C cross section in FIG. 1, and each of the same (B) shows a D cross section in FIG. 1, which is the same as FIGS. 7 and 8. The same reference numerals are given to the parts and the description thereof will be omitted.

In the locking mechanism 2 of the present invention, in order to prevent one-sided locking, a limiting member 40 is provided substantially in the center of the rotating shaft 3, and an engaging portion 41 is provided at a position corresponding to the limiting member 40 of the lower machine body 30. .

The limiting member 40 has the same shape as the locked pieces 4 and 5,
Hook portion 40 that is larger than the hook portions 4a, 5a of the locked pieces 4, 5.
a. (See FIG. 1 (B)) The engaging portion 41 provided in the lower body 30 is mainly composed of a supporting member 42, a slide piece 43, and a retracting spring 44, and is not shown like the locking pieces 6 and 7. The slide projection 43a of the support member 42 fixed to the frame is loosely fitted into the elongated hole 43c of the slide piece 43, so that the slide piece 43 is slidably supported in the vertical direction.

One end of the retraction spring 44 is locked to a locking pin 43d provided upright on the slide piece 43, and the other end is locked to the support member 42. Therefore, the slide piece 43 is biased downward and is stopped at the position where the upper end of the elongated hole 43c and the support protrusion 42a are engaged, that is, the lower limit position.

In this state, the inclined surface 43a at the upper part of the slide piece is substantially on the same plane as the inclined pieces 6 and 7 inclined surfaces 6a and 7a, and the engaging hole 43b is at the same position as the engaging holes 6b and 7b (the rotation shaft 3 Position which is different only in the longitudinal direction).

When the upper body 29 is closed from the open state, the locked members 4, 5 and the restricting member 40 approach the locking pieces 6, 7 and the sliding member 43, respectively. (State shown in FIGS. 2A and 2B) When the upper body 29 is further closed, since the hook portion 40a is larger than the hook portions 4a and 5a as described above, the inclined surface 40b is first formed. Comes into contact with the inclined surface 43a, the rotating shaft 3 slightly rotates in the B'direction, and the hook portion 40a moves to the inclined surface 4a.
Go over 3a.

In the state immediately before the hook portion 40a reaches the locking hole 43b,
The hook portions 4a and 5a are separated from the locking pieces, and are located below the upper edges of the locking holes 6b and 7b. Even if the upper body is slightly twisted, as described above, the hook 4
The shape and size of the hook portion 40a are set so that the sides of a and 5a are located below the upper edges of the locking holes 6b and 7b. (See FIGS. 3A and 3B) When the hook portion 40a reaches the locking hole 43b, the hook portion 40a is fitted into the locking hole 43b. (See FIGS. 4 (A) and (B))
When the hook portion 40a is fitted into the locking hole 43b, the hook portions 4a, 5
Since “a” is located below the upper edges of the locking holes 6b and 7b, the hook portions 4a and 5a are completely caught in the locking holes 6b and 7b without being caught by the upper edges. Get in. Therefore, only one of the hooks 4a, 5a has locking holes 6b, 7
It does not fit into b. Further, since the hook portions 4a and 5a are not caught, the hook portion 40a is smoothly fitted into the locking hole 43b. When the operator releases the hand in this state, the upper body 29 is lifted upward because it is biased in the opening direction as described above, and the hook portions 4a and 5a are locked in the locking holes 6b and
The upper body 29 and the lower body 30 are completely locked by being locked to the upper edge of 7b. At this time, the slide piece member 43 is slightly pulled up against the biasing force of the tension spring 44. (See FIGS. 5 (A) and 5 (B)) As described above, when the upper body 29 is closed, the hook portions 4a and 5a of the locked members 4 and 5 are engaged with the upper edges of the locking holes 6b and 7b. Since it fits into the locking hole after completely crossing over the hook, the hooks 4a, 5
The one-side locked state in which only one side of the a is in the locked state does not occur.

[Effect of device]

As described in detail above, according to the present invention, since the one-side locked state in which only one of the plurality of locking mechanisms is locked does not occur, the upper body is suddenly opened during the image forming operation. In addition, there is no risk of causing such problems, and problems such as oblique feeding, paper jam, and unfixed one side do not occur.

[Brief description of drawings]

FIG. 1 (A) is a perspective view of a locking mechanism used in the present invention.
Figure (B) is an explanatory view of main parts in Figure 1 (A), Figure 2 (A), (B), Figure 3 (A), (B), Figure 4 (A), (B), 5 (A) and 5 (B) are both the first
FIG. 6A is a sectional view of an essential part of FIG. 6A, FIG. 6 is a configuration diagram of an image forming apparatus of the present invention, FIG. 7 is a perspective view of a conventional locking mechanism, and FIGS. 8A and 8B are conventional. It is a principal part sectional view of a locking mechanism. 2 ... Locking mechanism, 3 ... Rotating shaft, 4, 5 ... Locked member, 4
a, 5b ... hook portion, 6, 7 ... locking piece, 6b, 7b, 43b
... Locking hole, 40 ... Restricting member, 42 ... Supporting member, 43 ... Sliding member

Claims (1)

[Scope of utility model registration request] 1. An upper body is provided so as to be openable and closable with respect to a lower body by rotating about a horizontal axis, and an urging member for urging both bodies in an opening direction and the both bodies are locked at a closed position. In the image forming apparatus including a locking mechanism, the locking mechanism includes a plurality of first locking members provided on one of the two machine bodies, and a rotation locus of the upper machine body on the other of the two machine bodies. A first locked member that is movably supported in a predetermined direction that intersects with each other and that is locked to each of the plurality of first locking members when the two machine bodies are closed; A second locking member that is movable up and down, and a second locking member that is integrally movably connected to the first locked member that is provided on the other of the two machine bodies in the predetermined direction. A second locked member that is locked, and the second locking member when closing both the machine bodies. The second locked member is brought into contact with the second locked member so that the second locked member is moved in the predetermined direction until the first locked member exceeds the position where the first locked member is locked. And after moving in the closing direction, the second locked member is locked by the second locking member, and the upper body is biased in the opening direction by the biasing member. The image forming apparatus, wherein the locking member is moved upward and the first locked member is locked by the first locking member.