JP2556235B2 - Lock mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock mechanism of an image forming apparatus such as an electrophotographic printer, and more particularly, a lock mechanism in which a front side of a transfer unit is automatically rotated downward when a photosensitive drum unit is pulled out. It is about.

Recently, with the rapid spread of office automation equipment, electrophotographic printers are becoming widespread in copying machines, printers and the like. In this device, the photosensitive drum and the transfer device are separately mounted and positioned in the device, or the photosensitive drum and the transfer device are integrated into one unit. It is difficult to pull out, and when exchanging the photosensitive drum, it is necessary to remove the two units so as not to damage the transfer portion.

In addition, although the positional relationship is high in the integrated type,
Poor workability such as jam handling of printing paper and replacement of photosensitive drum. Therefore, a method that is easy to position and has good maintainability is desired.

[0004]

2. Description of the Related Art FIG. 5 illustrates an internal side view of an electrophotographic printing apparatus. In the figure, 1 is a cassette mounting portion, 2 is a cassette, 3 is a delivery roller, 4 is a conveying path, 5 is a printer section, and 6 is a stacker.

The printer section 5 includes an optical unit 50, a photosensitive drum 51a, a cleaner 52, a charging device 53, a developing device 54, and a transfer device 55.
a, a static eliminator 56, and a fixing device 57. A cassette 2 is set in the cassette mounting portion 1, and a desired size of printing paper (hereinafter referred to as paper) 2a is accumulated and stored in the cassette 2.

With such a configuration, the fixing unit 57 is heated to a predetermined temperature when the apparatus is turned on to be in a printable state, whereupon the paper is fed from the cassette 2 based on the print instruction signal.
2a is fed out in the direction of arrow A, conveyed along the conveying path 4 and sent below the photosensitive drum 51a. By this time, the photosensitive drum 51a has been neutralized by the static eliminator 56, the residual toner has been cleaned by the cleaner 52, and has been recharged by the charger 53.

Optical data emitted from an optical unit 50 composed of a laser light source or the like scans the photosensitive drum 51a, and the electrostatic image formed on the photosensitive drum 51a is developed into a toner image by a developing device 54, and then transferred to a transfer device. After being transferred onto the sheet 2a by 55a, it is fixed by the fixing device 57 and sent to the stacker 6.

Since the photosensitive drum 51a becomes dirty due to the adhesion of toner, it must be cleaned when necessary or periodically.
Also, since it is flawed by use, it is replaced when necessary. Further, the transfer device 55a is located directly below the photosensitive drum 51a and toner drops and becomes dirty, so that the transfer device 55a is regularly cleaned.

Therefore, the photosensitive drum 51a and the transfer device 55a
Since they are taken out from the device at the time of maintenance such as cleaning and replacement, they are configured to be detachable as follows. Figure 6 (a)
As shown in the side sectional view and the front sectional view of (b), the photosensitive drum 51a is housed in the housing 7a, and the housing 7a is the device frame.
8a, 8b is installed by being guided by rails 9a, 9b provided between them, one end of the shaft of the photosensitive drum 51a is connected to a motor shaft described later through couplings C1, C2, and the other end of the device frame 8a. It is pivotally supported by the cover plate 11.

More specifically, FIGS. 7 (a) and 7 (b)
As shown in the plan view and the side view, the rails 9a and 9b are provided so as to be slidable in the longitudinal direction, and the right ends thereof are connected by a pressing plate 90. Also, lock pins 91a, 91b on both sides of the left end
Is provided.

On the left side of the lock pins 91a, 91b, fulcrums 93a, 93
One end is rotatably supported by b and the lock lever 92a, which is urged to the stoppers 95a, 95b by the springs 94a, 94b.
92b is provided. Engaging grooves 96a, 96b are provided at the tips of the lock levers 92a, 92b.

Therefore, the housing 7a is held by the rails 9a and 9b, the coupling C1 is brought into contact with the coupling C2 of the motor shaft in the direction of the arrow with the center thereof aligned, and then the rails 9a and 9b are pushed in the same direction to press the pressing plates. Slide 90 until it contacts housing 7a.

In this process, the lock pins 91a of the rails 9a, 9b,
91b moves forward and engages with the engaging grooves 96a, 96b, and the lock lever
92a and 92b are rotated against the elasticity of springs 94a and 94b, and eventually springs 94a and 94b come to the opposite side of fulcrums 93a and 93b to restrict rails 9a and 9b from moving in the returning direction, and the housing It can be mounted by locking the position of 7a.

As shown in FIGS. 6 (a) and 6 (b), the transfer device 55a has leaf springs 10a-10d attached to the front, rear, left and right of its lower surface, and is attached to the lower side of the attached housing 7a. Department
When it is mounted on the housing 12a, it is pressed upward by the leaf springs 10a to 10d on the lower surface and comes into contact with the lower surface of the housing 7a for positioning.

Although not shown, a method is also used in which the photosensitive drum 51a and the transfer portion 55a are housed in a single housing and integrally mounted in the apparatus.

[0016]

According to the above-mentioned conventional method, in the method of separately mounting the photosensitive drum and the transfer device in the apparatus, the positional relationship between the photosensitive drum and the transfer device is difficult to be accurate.
Moreover, when replacing or cleaning the photosensitive drum and transfer unit,
It is necessary to remove each of the two units so as not to damage each other, and workability is poor. In the method of mounting the photosensitive drum and the transfer unit as a unit as a unit, the positional relationship can be obtained with high accuracy, but the workability of jamming the printing paper and exchanging the photosensitive drum is deteriorated. There is a problem.

An object of the present invention is to provide a lock mechanism which has good workability in maintenance such as jam clearance and replacement of the photosensitive drum.

[0018]

FIG. 1 is a principle view of the present invention, in which (a) is a side sectional view and (b) is a front view. In the figure, 7 is a first housing, 8 is a device frame, 12 is a second housing, 13 is a positioning hole, 14 is a positioning pin, 17 is an engaging claw,
18 is an arm, 70 is a first side plate, 120 is a second side plate, 51 is housed in the first housing 7 and is detachably attached to the device frame 8 in the axial direction, and the first housing 7 is attached. The first unit 55, which is positioned by inserting the plurality of positioning holes 13 provided in the first side plate 70 on the front side in the direction into the plurality of positioning pins 14 provided on the outside of the device frame 8, 55 is the first unit. Case 7
The second housing 12 is accommodated in the second housing 12 that is rotatably mounted in a direction away from the position parallel to the first housing 7 toward the front side below the tip side in the mounting direction of the When in the position parallel to the first housing 7, the first unit 51
A second unit 16 which is positioned in parallel with a predetermined gap is provided on the second side plate 120 of the second housing 12, is rotatably supported at an intermediate point, and has an engaging claw 17 at one end and an engaging claw 17 at the other end. A first lever 19 which has an arm 18 and is elastically biased toward the tip of the engaging claw 17 and whose rotation is restricted at a predetermined position is provided on the second side plate 120 of the second housing 12. When the first casing 7 and the second casing 12 are mounted on the device frame 8, the first lever 16
Has a first end at a position facing the arm 18 of the
The second lever that engages with the first side plate 70 and rotates to push the arm 17 to rotate the first lever 16 by pulling it out when the device is removed, and 15 is a lock provided on the device frame 8. It's a pin.

Therefore, when the second casing 12 is positioned in parallel with the first casing 7, the engaging claw 17 is locked by the lock pin 15.
When the first housing 7 is pulled out, the first lever 51 is rotated to rotate the first lever 51 and the first unit 51 and the second unit 55. The lever 16 is rotated so that the engaging claw 17 is disengaged from the lock pin 15.

[0020]

When the first casing 7 is mounted on the device, the positioning holes 13 are fitted into the positioning pins 14 of the device frame 8 for positioning, and then the front side of the second casing 12 is placed on the front side of the first casing 7.
When it is positioned in parallel with, the engaging claw 17 of the lever 16 engages with the lock pin 15 and the second housing 12 is locked to the first housing 7.

When the first casing 7 is removed from the apparatus for maintenance or the like, if the first casing 7 is pulled out to the front side, the first side plate 70
When the second lever 19 rotates, one end presses the arm 17 to rotate the first lever 16, and the engaging claw 17 that is locked by being engaged with the lock pin 15 is automatically It comes off, and with this, the front side of the second housing 12 opens downward.

Therefore, when the first casing 7 is pulled out, the second casing 12 is opened interlockingly, so that the workability is remarkably improved. For example, the first unit 51 is the photosensitive drum and the second unit 55 is the transfer portion. In the case of a certain electrophotographic printing apparatus, it is possible to easily perform processing for paper jams, cleaning and replacement of the photosensitive drum, and cleaning of the transfer portion.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same reference numerals denote the same objects throughout the drawings.

FIG. 2 is a schematic view of the essential parts of the present invention applied to the electrophotographic printing apparatus described in the prior art. The housing 7b of FIG.
The housing 12b, the lock lever 16a, the release lever 19a, the photosensitive drum 51a, the side plate 70a and the side plate 120a are the first housing 7, the second housing 12, the first lever 16 and the second lever 1 of FIG.
9, first unit 51, second unit 55, first side plate 7
0 and the second side plate 120, respectively.

As shown in the side sectional views and front views of FIGS. 2 (a) and 2 (b), the photosensitive drum 51a is housed in the housing 7b.
7b includes tongue pieces 71a,
71b is provided so as to overlap with the front of the device frame 8b. Positioning holes 13a, 13b at the tips of the tongue pieces 71a, 71b
Is provided.

The device frame 8b is provided with positioning pins 14a and 14b facing outwards at positions corresponding to the positioning holes 13a and 13b when the housing 7b is mounted, and the opposite side of the positioning pin 14a of the device frame 8b is provided. That is, the lock pin 15a is provided concentrically with the positioning pin 14a toward the inside.

An L-shaped holding spring 121 is fixed to the lower left end of the housing 12b, and the vertical portion in the figure is in contact with the device frame 8b. The transfer device 55b is housed in the housing 12b, and a lock lever is provided on the side plate 70a at the front end of the transfer device 55b.
16a and a release lever 19a are provided. FIG. 3 shows an enlarged perspective view of the lock lever 16a and the release lever 19a.

As shown in FIG. 3, the lock lever 16a is
It is formed in a substantially U shape inside the side plate 120a, is rotatably supported by the support shaft 122 at the lower corner, and is composed of an upper side having an engaging claw 17a at its tip and a lower side having an arm 18a. 12
The spring 123 wound around 2 urges the engaging claw 17a in the direction of the tip of the engaging claw 17a, that is, in the direction of the arrow B in the figure, and the stopper 124 regulates the rotation at a predetermined position.

The release lever 19a is L-shaped and has horizontal and vertical sides formed as a pressing portion 126 and an engaging portion 127, and extends from the hole 128 formed in the side plate 120a to the inside and outside of the side plate 120a. The corner portions are rotatably supported by the support shaft 125.

The pressing portion 126 is located inside the side plate 120a and has its tip facing the lower side near the tip of the arm 18a of the lock lever 16a, and is engaged with the stopper 129 at a substantially horizontal position to rotate only in the upward direction. Is configured to.

The engaging portion 127 is located outside the side plate 120a,
The tongue piece 71 of the side plate 70a is pulled out when the housing 7b is removed.
It is formed so that it is engaged with the tip of a and pivots to press the arm 18a to pivot the lock lever 16a in the direction of arrow C against the elastic force of the spring 123. Then, when the casing 12b is mounted in parallel under the casing 7b, the tip of the tongue piece portion 71a is arranged so as to come to a position facing the inside of the engaging portion 127.

Further, as shown in FIG. 4 (a), the housing 12b is formed in a rectangular box shape having an opening at the top, and the device frame 8b
The tip end is laterally supported by a support shaft 80 provided on the front side, and the front side is rotated downward to open with respect to the housing 7b (shown by a chain double-dashed line in FIG. 2 (a)). . Also the housing
A leaf spring 130 is mounted on the bottom surface of 12b.

The transfer device 55b has springs 20a, 20b at its tip.
Are attached, and rollers 21a to 21 are attached to the front, rear, left, and right ends of the upper surface.
d is provided. Therefore, when it is inserted into the housing 12b,
The front side is pressed by the springs 20a and 20b into the inner wall of the end portion of the housing 12b to be housed therein, and is pressed upward by the leaf spring 130.

Therefore, as shown in FIG. 4 (b), when the housing 7b is mounted, the rollers 21a to 21d of the transfer device 55b are moved to the photosensitive drum 51a.
The photosensitive drum 51a and the transfer device 56 are brought into contact with both ends of the outer periphery of the photosensitive drum 51a.
The gap b is determined.

With this construction, when the housing 12b is mounted on the device frame 8b and then the housing 12b is positioned parallel to the housing 7b, the engaging claws of the lock lever 16a
The back slope of 17a hits the lock pin 15a, and the engaging claw 17
a rotates in opposition to the elasticity of the spring 123 and escapes in the direction of arrow C.

When the lock pin 15a enters the inside of the engaging claw 17a, the lock lever 16a rotates in the direction of the arrow B by the elastic force of the spring 123, the engaging claw 17a engages with the lock pin 15a, and the housing 12b. Is locked in the case 7b. At this time, the rollers 21a to 21d come into contact with both ends of the outer periphery of the photosensitive drum 51a, and the gap between the photosensitive drum 51a and the transfer device 55b is determined.

When the photosensitive drum 51a is taken out of the apparatus frame 8b for the purpose of jamming the sheet 2a, maintenance such as cleaning and replacement, etc., when the housing 7b is pulled out forward, the tip of the tongue piece 71a releases the release lever. The release lever 19a is rotated in the direction of arrow D by engaging with the engaging portion 126 of the arm 19a.
Is pressed to rotate the lock lever 16a in the direction of arrow C, and the lock pin 15a is released from the engagement to unlock the housing 12b.

Then, as shown by the chain double-dashed line in FIG. 2 (a), the tip of the housing 12b rotates in a direction away from the housing 7b,
The holding spring 121 bends to hold the housing 12b at an inclined position. Therefore, the photosensitive drum 51a and the transfer device 55b can be cleaned or replaced by pulling out the housing 7b and removing it from the mounting. In the case of a jam of the sheet 2a, it can be easily processed in a state where the front end of the housing 12b is rotated in a direction away from the housing 7b.

In this way, the transfer device 55b in the housing 12b
Is the photosensitive drum by the spring 123 and the rollers 21a to 21d.
The clearance with 51a is determined to improve the position accuracy, and the lock is released by pulling out the housing 7b, and the housing 12b is interlocked and opens downward from the front side, improving workability and handling paper jams and exposure to light. Cleaning and replacing the drum 51a, and the transfer device 55
The cleaning of b can be easily performed.

[0040]

As described above, according to the present invention, the first housing containing the first unit and the second housing containing the second unit are locked by the common positioning pin,
When the first housing is pulled out, the second housing is opened in conjunction with each other, so that workability is significantly improved. For example, in the case of an electrophotographic printing apparatus in which the first unit is a photosensitive drum and the second unit is a transfer unit. Has an effect that it is possible to easily perform processing for paper jam, cleaning and replacement of the photosensitive drum, and cleaning of the transfer portion.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram of an example.

FIG. 4 is a block diagram of a transfer device and a housing.

FIG. 5 is an internal side view of the electrophotographic printing apparatus.

FIG. 6 is a configuration diagram showing a conventional example.

FIG. 7 is an explanatory diagram of mounting the photosensitive drum.

[Explanation of symbols]

7 is the first housing, 7a, 7b, 12a, 12b are the housings, 8,8a,
8b is a device frame, 12 is a second housing, 13,13a are positioning holes, 14,14a and 14b are positioning pins, 15 and 15a are locking pins, 16 is a first lever, 16a is a locking lever and 17,17a Is an engaging claw, 18,18a is an arm, 19
Is a second lever, 19a is a release lever, 51 is a first unit, 51a is a photosensitive drum, 55 is a second unit,
55a and 55b are transfer devices, 70 is a first side plate, 70a and 120a are side plates, 120 is a second side plate,

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-56-119151 (JP, A) JP-A-63-163870 (JP, A) JP-A-63-298268 (JP, A) JP-A-58- 163963 (JP, A) JP-A-4-86836 (JP, A) JP-A 64-40848 (JP, A) JP-A 63-296078 (JP, A) JP-A 1-170973 (JP, A) Actual Development Sho 60-184072 (JP, U)

Claims (2)

(57) [Claims] 1. A first housing which is housed in a first housing (7) and is detachably attached to an apparatus frame (8) in an axial direction.
A plurality of positioning holes (13) provided in the first side plate (70) on the front side with respect to the mounting direction of (7) are respectively provided in the plurality of positioning pins (14) provided on the outside of the device frame (8). The first unit (51) that is fitted and positioned, and the first unit (51) is located below the front end side in the mounting direction of the first housing (7) and is centered on the tip and is parallel to the first housing (7). When the second housing (12) is accommodated in the second housing (12) mounted so as to be rotatable in the direction in which the side separates, and the second housing (12) is in a position parallel to the first housing (7), the first housing A second unit (55) positioned in parallel with the unit (51) of the second unit (51), the second unit corresponding to the first side plate (70) of the first housing (7). It is provided on the second side plate (120) of the housing (12), is rotatably supported at an intermediate point, has an engaging claw (17) at one end, and forms an arm (18) at the other end. Place it elastically in the direction of the tip of the jaw (17). First lever pivot position is regulated (16)
And provided on the second side plate (120) of the second housing (12), and the device frame (8) includes the first housing (7) and the second housing.
When the (12) is attached, the arm (1) of the first lever (16) is
8) has one end at a position opposite to 8) and engages with the first side plate (70) by the pulling out when the first housing (7) is removed to rotate the arm (18). A second lever (19) for pressing and rotating the first lever (16), and positioning the second housing (12) in parallel with the first housing (7). When the engaging claw (17) is released, the device frame (8)
The second casing (12) is locked to the first casing (7) by engaging with the lock pin (15) provided on the second casing (7) and the second casing (7) is pulled out when the first casing (7) is pulled out. Lever (1
The rotation of 9) causes the first lever (16) to rotate and the engagement claw (17)
The lock mechanism is characterized in that it is configured to be disengaged from the lock pin (15). 2. The lock pin (15) is the positioning pin.
(14) The lock mechanism according to claim 1, wherein: