Image forming system

Abstract

To increase safety of the entire apparatuses in a state in which two or more apparatuses are connected with each other, and improve usability.SOLUTION: A lock mechanism 150 has a lock member 152 that has a hook part 155 and a bar member 151. A lock state is maintained by a repulsive force generated by contact of the hook part 152 with a main body frame 30 and exerted from the main body frame 30 to the hook part 155 and a force generated by contact of the bar member 151 with the lock member 152 and exerted from the bar member 151 to the lock member 152. The hook part 155 is separated from the main body frame 30 and the bar member 151 is separated from the lock member 152, and thereby a release state is maintained by the self weight of the lock member 152.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an image forming system, for example, an image forming apparatus such as a copying machine or a printer, and a paper feeding device attached thereto. [Background technology]

[0002] Generally, a removable function expansion device is attached to an image forming apparatus such as a printer. In some cases, multiple function expansion devices can be attached, and multiple identical function expansion devices can be attached, or a second function expansion device can be attached to a first function expansion device. For example, attaching multiple feed function expansion devices to an image forming apparatus increases the sheet stacking capacity and enables it to handle a large number of print jobs. Another example is attaching a base with casters below the image forming apparatus or a feed function expansion device to facilitate movement of the entire apparatus.

[0003] An image forming apparatus has been proposed that is equipped with a locking mechanism that uses a locking claw to lock devices together when a function expansion device is attached to the image forming apparatus, or when another function expansion device is attached to a function expansion device (see, for example, Patent Document 1). This mechanism is provided to prevent the devices from becoming uncoupled and becoming unstable during installation or transportation. The locking mechanism is required to have the following two features. First, it is required to lock the devices together so that the entire apparatus is highly stable and robust. Second, it is required to enable the user to switch between a locked state and an unlocked state, allowing the user to freely couple or uncouple the devices together. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-070279 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional configuration has the following concerns. First, in consideration of the precision of the components between the devices, a gap is necessary between the locking claw of the locking housing and the engaged part of the locked housing. There is a concern that this gap could cause the entire image forming device, with the function expansion device attached, to become unsteady. For example, if a base with casters is attached to the device, the casters could hit a step and cause the upper device to lift up, giving the user the impression that the entire device is unstable.

[0006] Second, when the locking claw is switched to a position corresponding to the locked state when the function expansion device is in a standalone state, that position is maintained. When connecting devices, it is desirable that the locking claw be in a position corresponding to the unlocked state so that the locking claw of the locking housing and the engaged portion of the locked housing do not interfere with each other. However, in conventional configurations, the locking claw is maintained in a position corresponding to the locked state when the locking housing is in a standalone state. In this case, there is a concern that the locking claw may be deformed by the locked housing, or that the user may have to take their hand off the locked housing and operate it to a position corresponding to the unlocked state. For these reasons, there is a demand for improving the stability of the entire device when two or more devices are connected, as well as improving usability.

[0007] The present invention has been made under these circumstances, and aims to increase the stability of the entire device when two or more devices are connected together, and to improve usability. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention has the following configuration. (1) An image forming system for forming an image on a recording material, comprising a first device having a first housing and a second device having a second housing, the first device being stacked on top of the second device in a vertical direction, the system further comprising a locking mechanism for locking the first device and the second device, or releasing the locked state, the locking mechanism comprising a first member provided on the second housing and having a hook portion that can be in a state of contact with the first housing or in a state of being spaced apart from the first housing, and a first member that can contact the first member to cause the hook portion to contact the first housing. and a second member that moves the hook portion away from the first housing by moving the hook portion away from the first member, wherein the locked state is maintained by a repulsive force exerted from the first housing on the hook portion when the hook portion abuts against the first housing and a force exerted from the second member to the first member when the second member abuts against the first member, and the released state is maintained by the weight of the first member when the hook portion moves away from the first housing and the second member moves away from the first member. [Effects of the Invention]

[0009] According to the present invention, it is an object to improve the stability of the entire device when two or more devices are connected together, and to improve usability. [Brief explanation of the drawings]

[0010] [Figure 1] Cross-sectional view of an image forming apparatus according to first to third embodiments. [Figure 2] 1 is a perspective view of a frame of an image forming apparatus main body according to a first embodiment, viewed from the bottom in the vertical direction; [Figure 3] FIG. 1 is a perspective view of a frame of an expansion feeding unit according to a first embodiment, viewed from the bottom in the vertical direction; [Figure 4] FIG. 1 is a perspective view of an expansion feeding unit according to a first embodiment, viewed from above in the vertical direction; [Figure 5] FIG. 1 is a perspective view of a locking mechanism according to a first embodiment; [Figure 6] Detailed view of the locking mechanism in the locked state in the first embodiment [Figure 7] Detailed view of the locking mechanism in the intermediate state of the first embodiment [Figure 8] Detailed view of the locking mechanism in the unlocked state in the first embodiment [Figure 9] FIG. 1 is a detailed view showing the force acting on the locking mechanism in the locked state according to the first embodiment. [Figure 10] Detail diagram of the locking mechanism when the expansion feeding unit is used alone in the first embodiment. [Figure 11] Detailed view of the locking mechanism in the locked state in the second embodiment [Figure 12] Detailed view of the locking mechanism in the unlocked state in Example 2 [Figure 13] Detailed view of the locking mechanism in the locked state in the third embodiment [Figure 14] Detail view of the locking mechanism in the unlocked state in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions. Therefore, unless otherwise specified, it is not intended that the scope of the present invention be limited to these. [Example]

[0012] [Overall configuration of image forming device] FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming system having an image forming apparatus and a function expansion device according to a first embodiment. In FIG. 1, a laser beam printer is shown as an example of an image forming apparatus. A plurality of expansion feeding units and a base with casters are also shown as examples of a function expansion device. The laser beam printer, the plurality of expansion feeding units, and the base with casters constitute an image forming system for forming an image on a recording material.

[0013] The image forming apparatus main body 1 is equipped with a drum-shaped electrophotographic photosensitive member (hereinafter referred to as photosensitive drum) 8 as an image carrier. The photosensitive drum 8 is configured by providing a photosensitive material such as an organic photoconductor (OPC), amorphous selenium, or amorphous silicon on a cylindrical drum base made of aluminum, nickel, or the like. The photosensitive drum 8 is rotatably supported by the image forming apparatus main body 1 and is driven to rotate at a predetermined process speed by a drive source. Around the photosensitive drum 8, a charging member 80, a developing member 81, and a transfer roller 9 as a transfer member are arranged in this order along the rotational direction. In addition, a scanner unit 7 as an exposure means is arranged above the photosensitive drum 8. The photosensitive drum 8, charging member 80, and developing member 81 are configured as a process cartridge 6 that is detachably attached to the apparatus main body.

[0014] Other components of the image forming apparatus main body 1 include, in order along the conveyance path of the recording material S1, a cassette 2 for loading recording material S1 such as paper, a paper feed roller 3 as a paper feeding means, a pair of conveyance rollers 4, and a pair of registration (hereinafter referred to as registration) rollers 5. The image forming apparatus main body 1 also includes a fixing device 10 as a fixing means, a pair of discharge rollers 11, and a discharge tray 12.

[0015] [Operation of image forming device] Next, the operation of the image forming apparatus main body 1 will be described. The photosensitive drum 8, which is driven to rotate by the drive source, is uniformly charged to a predetermined polarity and a predetermined potential by the charging member 80. After charging, the surface of the photosensitive drum 8 is exposed to light based on image information by the scanner unit 7, and the charge in the exposed area is removed to form an electrostatic latent image (latent image). The electrostatic latent image is developed by the developing member 81 and visualized as a toner image.

[0016] The toner image on the photosensitive drum 8 is transferred onto the recording material S1 by the transfer roller 9. The transfer roller 9 is urged toward the photosensitive drum 8 by an urging member (not shown). With this configuration, a transfer nip is formed between the transfer roller 9 and the photosensitive drum 8. In this way, the transfer roller 9 performs a transfer operation to transfer the toner image on the photosensitive drum 8 (on the image carrier) onto the recording material S1 at the transfer nip.

[0017] Meanwhile, recording material S1 is fed by a paper feed roller 3 from a cassette 2 that stores a stack of recording material S1. The recording material S1 is conveyed to the transfer nip portion via a pair of conveying rollers 4 and a pair of registration rollers 5. An unfixed toner image transferred from the photosensitive drum 8 to the recording material S1 at the transfer nip portion is heated and fixed by a fixing device 10. After passing through the fixing device 10, the recording material S1 is discharged onto a discharge tray 12 via a pair of discharge rollers 11.

[0018] [About the bottom of the image forming device] Next, the configuration of the bottom of the image forming apparatus main body 1 will be described. FIG. 2 is a perspective view of the main body frame 30 of the image forming apparatus main body 1, which is the first device, viewed from below, and also shows the up-down, left-right, and front-to-back directions. The image forming apparatus main body 1 has the main body frame 30, which is the first housing. The main body frame 30 has a left side panel 31 and a right side panel 32 made of a conductor such as metal. The main body frame 30 has grounding portions 21a-21d and device installation portions 22a-22d on its bottom surface. The grounding portions 21a-21d are portions that come into contact with a desk when the image forming apparatus main body 1 is placed on the desk, for example, and are, for example, surfaces with a certain area. The device installation portions 22a-22d are surfaces that come into contact with the extended feeding unit 100 (see FIG. 1, etc., described below) when the image forming apparatus main body 1 is placed on the extended feeding unit 100, and are, for example, surfaces with a certain area.

[0019] In some cases, a member with a high friction coefficient, such as rubber, is attached to the contact portions 21a-21d to prevent the image forming apparatus main body 1 from sliding on a desk or other surface due to user operation, etc. Therefore, when the image forming apparatus main body 1 is installed on the extended feeding unit 100, if the contact portions 21a-21d are installed on the extended feeding unit 100, the amount of compression of the rubber will not be uniform due to differences in weight balance. As a result, the position and inclination of the image forming apparatus main body 1 relative to the extended feeding unit 100 will not be constant, which may cause skew during transport of the recording material S2 (see FIG. 1) from the extended feeding unit 100, leading to concerns about a decrease in image quality, etc. Therefore, when the image forming apparatus main body 1 is installed on the extended feeding unit 100, the device installation portions 22a-22d, separate from the contact portions 21a-21d, are configured to contact the extended feeding unit 100.

[0020] Positioning holes 23a to 23c are provided on the bottom surface of the main body frame 30. The positioning hole 23a on the right side plate 32 is, for example, a round hole provided on the front right side of the main body, and the positioning hole 23c is, for example, an oblong hole provided on the rear right side of the main body. Note that the positioning hole 23a may be an oblong hole and the positioning hole 23c may be a round hole. The positioning hole 23b on the left side plate 31 is an oblong hole provided on the front left side of the main body. These positioning holes 23a to 23c are used for positioning with the extended feeding unit 100, which will be described later. The bottom surface of the main body frame 30 is provided with a hole 90b on the front side of the left side plate 31 and a hole 90a on the rear side of the right side plate 32. The holes 90 (90a, 90b) are holes through which hook portions of a locking mechanism, which will be described later, are passed. Contact portions 27 (see FIG. 6, etc.) that contact the hook portions of the locking mechanism are provided near the holes 90b, 90a on the left side plate 31 and right side plate 32.

[0021] [Configuration of the extended feeding unit] Next, we will explain the extended feeding units 100 and 200 externally connected to the image forming apparatus main body 1 and the caster-equipped base 500 externally connected to the extended feeding unit 200. As shown in FIG. 1, the extended feeding unit 100, which is the second device, is attached below the image forming apparatus main body 1 and can be connected to the image forming apparatus main body 1 from below. That is, the image forming apparatus main body 1, which is the first device, is stacked on top of the extended feeding unit 100, which is the second device, in the vertical direction, and the first and second devices operate in cooperation to form an image on a recording material. The extended feeding unit 100 has a cassette 102 that stores sheets S2, a paper feed roller 103 that feeds sheets S2 stored in the cassette 102, and a conveying roller pair 104 that conveys the sheets S2. The sheets S2 stored in the cassette 102 are fed by the paper feed roller 103 and sent into the image forming apparatus main body 1 by the conveying roller pair 104, where an image is formed through the process described above.

[0022] Further, the extended feeding unit 200 is mounted below the extended feeding unit 100 and can be connected to the extended feeding unit 100 from below. The extended feeding unit 200 has a cassette 202 in which sheets S3 are stored, a paper feed roller 203 that feeds the sheets S3 stored in the cassette 202, and a pair of conveying rollers 204 that convey the sheets S3. The sheets S3 stored in the cassette 202 are fed by the paper feed roller 203 and sent into the extended feeding unit 100 by the pair of conveying rollers 204, and then sent into the image forming apparatus main body 1, where an image is formed through the process described above.

[0023] In this way, the extended feeding units 100, 200 can be connected in a stacked manner to the image forming apparatus main body 1, making it possible to increase the amount and types of sheets S that can be stored inside the image forming apparatus main body 1. Furthermore, the extended feeding units as function expansion devices are not limited to two levels, and it is possible to connect three or more levels of extended feeding units. These extended feeding units 100, 200 have the same configuration, and the paper feed rollers 103, 203 and cassettes 102, 202 that they each have are the same configuration as the paper feed roller 3 and cassette 2 of the image forming apparatus main body 1.

[0024] [About the bottom of the function expansion device] Figure 3 is an oblique view of the frame 130, which is the second housing of the extended feeding unit 100, viewed from below in the vertical direction, and Figure 4 is an oblique view of the extended feeding unit 100 viewed from above in the vertical direction, also showing the up-down, left-right, and front-to-back directions.

[0025] 3, the frame 130 has a left side plate 131 and a right side plate 132. As with the image forming apparatus main body 1, the bottom surface of the extended feeding unit 100 is provided with grounding portions 121a to 121d and device installation portions 122a to 122d. The grounding portions 121a to 121d are surfaces that come into contact with the desk when the extended feeding unit 100 is installed on the desk or the like. The device installation portions 122a to 122d are surfaces that come into contact when the extended feeding unit 100 is installed on the extended feeding unit 200.

[0026] A member with a high friction coefficient, such as rubber, is attached to the contact portions 121a-121d to prevent the extended feeding unit 100 from sliding on a desk or the like due to user operation, etc. Therefore, when the extended feeding unit 100 is installed on the extended feeding unit 200, if the contact portions 121a-121d with rubber or the like attached are installed on the extended feeding unit 200, the amount of compression of the rubber will not be uniform due to differences in weight balance. As a result, the extended feeding unit 100 may tilt relative to the extended feeding unit 200, which may result in a deterioration in image quality due to skew during transport of the recording material S3. Therefore, the device installation portions 122a-122d are configured to come into contact with the extended feeding unit 200 when the extended feeding unit 100 is installed on the extended feeding unit 200.

[0027] Positioning holes 123a to 123c are provided on the bottom surfaces of the left side plate 131 and the right side plate 132. These positioning holes 123a to 123c correspond to positioning pins, which will be described later, and are used for positioning when connecting the extended feeding unit 200 below the extended feeding unit 100. The bottom surface of the frame 130 is provided with a hole 190b on the front side of the left side plate 131 and a hole 190a on the rear side of the right side plate 132. The holes 190 (190a, 190b) are holes through which hook portions of a locking mechanism, which will be described later, are passed. Also, abutting portions that abut against the hook portions of the locking mechanism are provided near the holes 190 (190a, 190b).

[0028] As shown in FIG. 4, positioning pins 140 to 142 are provided at three locations on the top surface of the extended feeding unit 100. In FIG. 4, the outer side of the left side plate 131 is covered by a cover 131a, and the outer side of the right side plate 132 is covered by a cover 132a. The positioning pins 140 and 141 are arranged on both ends of the longitudinal direction (left-right direction) of the conveying roller pair 104. Here, the longitudinal direction of the conveying roller pair 104 is also the direction perpendicular to the conveying direction of the recording material S. The positioning pin 140 is arranged on the front side of the right side plate 132 in the front-rear direction in the conveying direction of the recording material S1, and the positioning pin 141 is arranged on the front side of the left side plate 131 in the front-rear direction in the conveying direction of the recording material S1. The positioning pins 140 and 142 are arranged near both ends of the right side plate 132 in the front-rear direction in the conveying direction of the recording material S1. The positioning pin 142 is disposed on the rear side in the front-rear direction of the right side plate 132 in the conveying direction of the recording material S1. The image forming apparatus main body 1 and the expansion feeding unit 100 are electrically connected by a drawer connector 160.

[0029] The expansion feeding unit 100 includes a cassette guide 120 and a locking mechanism 150. The locking mechanism 150 includes a tensioning member 151, a locking member 152, an operating unit 159, and the like. The locking mechanism 150 will be described later. As shown in FIG. 3, the locking mechanism 150 is provided on the surface of the right side plate 132 facing the outside. As shown in FIG. 4, the locking mechanism 150 is covered by a cover 132a, thereby sealing the space formed by the right side plate 132 and the cover 132a. The same applies to the locking mechanism 150 provided on the left side plate 131. The configurations of the grounding portion, device installation portion, positioning holes, and positioning pins in the expansion feeding unit 200 are the same as those in the expansion feeding unit 100, and therefore detailed description thereof will be omitted. Note that, when focusing on the expansion feeding unit 100 and the expansion feeding unit 200, the expansion feeding unit 100 corresponds to the first device, and the expansion feeding unit 200 corresponds to the second device.

[0030] 1, the wheeled base 500 is disposed below the extended feeding unit 200 and can be connected to the extended feeding unit 200 from below, facilitating movement of the entire device. Similar to the extended feeding unit 100, the top surface of the wheeled base 500 is also provided with a plurality of positioning pins (for example, three) and a locking mechanism. Note that, when focusing on the extended feeding unit 200 and the wheeled base 500, the extended feeding unit 200 corresponds to a first device, and the wheeled base 500 corresponds to a second device.

[0031] [Positioning method] Next, a method for positioning and fastening the image forming apparatus main body 1 and the extended feeding unit 100 will be described. When the image forming apparatus main body 1 is placed on the extended feeding unit 100, the extended feeding unit 100 is placed so that positioning pins 140 to 142 of the extended feeding unit 100 fit into positioning holes 23a to 23c provided in the image forming apparatus main body 1, respectively. Since the positioning pins 140 and 141 are arranged on both ends of the conveying roller pair 104 in the longitudinal direction, the conveying roller pair 104 can be accurately positioned with respect to the conveying roller pair 4 of the image forming apparatus main body 1. By accurately positioning the conveying roller pair 104, deterioration of image quality due to skew during conveyance of the recording material S2 is prevented.

[0032] Furthermore, the positioning pins 140 and 142 are disposed near both ends of the right side plate 132 in the front-to-rear direction in the conveyance direction of the recording material S1. Therefore, in addition to the effect of the positioning pins 140 and 141, it is possible to suppress misalignment between the extended feeding unit 100 and the image forming apparatus main body 1, thereby minimizing gaps and steps in the exterior. The positioning configuration in the extended feeding unit 200 is similar, so a detailed description will be omitted.

[0033] [Connection method using locking mechanism] The locking mechanism 150, which is a characteristic configuration of the first embodiment, will be described with reference to FIGS. 2 to 9. The locking mechanism 150 is in a locked state in which the first device and the second device are connected (fixed) and relative movement is restricted (hereinafter referred to as locked), or in an unlocked state (released state) in which the locked state is released. FIG. 5 is a perspective view of the locking mechanism 150. FIG. 6 is a diagram showing the locked state of the locking mechanism 150 when the image forming apparatus main body 1 is connected to the extended feeding unit 100. FIG. 7 is a diagram showing an intermediate state in which the locking mechanism 150 transitions from the locked state to the unlocked state. FIG. 8 is a diagram showing the unlocked state of the locking mechanism 150.

[0034] The locking mechanism 150 is composed of a tension member 151, a locking member 152, a pivot 153 for the locking member 152, a pivot 154 for the tension member 151, and a link member 156, and is mounted on a lock-side housing (hereinafter referred to as the lock-side housing). For example, if the two devices to be connected are the image forming apparatus main body 1 and the extended feeding unit 100, the lock side refers to the extended feeding unit 100. In this case, the lock-side housing refers to the frame 130 of the extended feeding unit 100. Furthermore, if the two devices to be connected are the extended feeding unit 100 and the extended feeding unit 200, the lock side refers to the extended feeding unit 200. In this case, the lock-side housing refers to the frame of the extended feeding unit 200. Furthermore, if the two devices to be connected are the extended feeding unit 200 and the base with casters 500, the lock side refers to the base with casters 500. In this case, the housing on the lock side refers to the frame of the base 500 with casters.

[0035] Locking member 152, which is the first member, has hook portion 155, which comes into contact with the housing on the locked side (hereinafter referred to as the locked-side housing). Hook portion 155 is provided on frame 130, which is the second housing, and is in a state of abutting against main body frame 30, which is the first housing, or in a state of being spaced apart from main body frame 30. Locking member 152 has rotating shaft 153, which is the first rotating shaft, and abutting portion 152a, which is provided on the opposite side of rotating shaft 153 from hook portion 155, and is in a state of being a first abutting portion that abuts against core tension member 151 in the locked state.

[0036] For example, if the two devices to be connected are the image forming apparatus main body 1 and the extended feeding unit 100, the locked side refers to the image forming apparatus main body 1. In this case, the housing on the non-locked side refers to the main body frame 30 of the image forming apparatus main body 1. Also, for example, if the two devices to be connected are the extended feeding unit 100 and the extended feeding unit 200, the locked side refers to the extended feeding unit 100. In this case, the housing on the locked side refers to the frame 130 of the extended feeding unit 100. Furthermore, for example, if the two devices to be connected are the extended feeding unit 200 and the caster-equipped base 500, the locked side refers to the extended feeding unit 200. In this case, the housing on the locked side refers to the frame of the extended feeding unit 200.

[0037] The second member, core tension member 151, has an operating part 159 (see FIG. 4) that can be operated by the user. As shown in FIG. 4, operating part 159 protrudes from the inner surface of left side plate 131 (or right side plate 132), and the user accesses operating part 159 (locking mechanism 150) from inside frame 130. Note that left side plate 131 (right side plate 132) is provided with a guide hole 131b that guides operating part 159 so that core tension member 151 can be rotated (or moved) via operating part 159.

[0038] The core tensioning member 151 abuts the hook portion 155 against the main body frame 30 by abutting against the locking member 152, which is the first member, and moves away from the locking member 152, thereby moving the hook portion 155 away from the main body frame 30. The core tensioning member 151 is provided on the frame 130. As shown in Figure 6 and other figures, the core tensioning member 151 and the locking member 152 are in contact at the end of the locking member 152 opposite the hook portion 155 and the end of the core tensioning member 151 opposite the pivot shaft 154. The core tensioning member 151 has an abutment portion 151a, which is a second abutment portion that abuts against the abutment portion 152a of the locking member 152 in the locked state. Core tensioning member 151 has a rotation axis 154, which is a second rotation axis, and rotation around rotation axis 154 causes abutment portion 151a to abut against or move away from abutment portion 152a. The rotation of core tensioning member 151 is performed by an operating portion 159. Core tensioning member 151 and locking member 152 are biased by their own weight into a position corresponding to the unlocked state.

[0039] The extended feeding unit 100, which is the locking housing, is detachable from the image forming apparatus main body 1, which is the locked housing, and the housings can be locked together by a locking mechanism 150. As shown in FIG. 4 , the locking mechanisms 150 are mounted in two locations, on the front left and rear right of the extended feeding unit 100, and a locking member 152 protrudes from the top surface of the extended feeding unit 100. More specifically, a pivot shaft 153 for the locking member 152 and a pivot shaft 154 for the core tensioning member 151 are mounted on the left side plate 131 and the right side plate 132. The locking member 152 is supported on the pivot shaft 153 of the locking member 152, and the core tensioning member 151 is supported on the pivot shaft 154 of the core tensioning member 151.

[0040] The link member 156 has an engagement portion 157 for the locking member 152 and an engagement portion 158 for the core tensioning member 151, and connects the core tensioning member 151 and the locking member 152. One end (engagement portion 157) of the link member 156 is provided near the abutment portion 152a of the locking member 152, and the other end (engagement portion 158) is provided near the abutment portion 151a of the core tensioning member 151, and transmits the movement of the core tensioning member 151 to the locking member 152. As shown in Figure 5 and other figures, the engagement portion 158 of the link member 156 is an elongated hole, and an engagement portion 151b that the core tensioning member 151 has near the abutment portion 151a fits into the elongated hole of the engagement portion 158. The engagement portion 151b moves through the elongated hole in response to the rotation of the core tensioning member 151.

[0041] [Lock Status] First, the forces acting on the locking mechanism 150 in the locked state when the image forming apparatus main body 1 is connected to the extended feeding unit 100 will be described with reference to FIGS. 6 and 9. FIG. 9 shows the directions of forces F1 and F2 acting on the locking mechanism 150 in the locked state. For ease of explanation, the link member 156 is not shown in FIG. 9. The hook portion 155 is configured to slightly deform the abutting portion 27 to ensure contact. Therefore, a repulsive force in the direction F1 (hereinafter referred to as repulsive force F1) acts on the hook portion 155. This repulsive force F1 acts as a moment that rotates the locking member 152 in the clockwise direction M1 in FIG. 9. The moment that rotates the locking member 152 in the clockwise direction M1 is transmitted to the tensioning member 151, which is in contact with the locking member 152, as a force in the direction F2 (hereinafter referred to as force F2). Here, the abutment portion 151a, which is the contact point between the core tensioning member 151 and the locking member 152, is arc-shaped, and a perpendicular line to this arc passes approximately through the center of the pivot shaft 154 of the core tensioning member 151 (broken line). Therefore, the force F2 acting from the locking member 152 to the core tensioning member 151 is directed toward the pivot shaft 154 of the core tensioning member 151, acting as a compressive force on the core tensioning member 151 (solid arrow in the figure), and is supported by the compressive rigidity of the core tensioning member 151. At this time, the locking member 152 receives a reaction force (-F2) (broken arrow in the figure) from the core tensioning member 151 against the compressive force F2, which acts as a moment to rotate it in the counterclockwise direction M2 in Figure 9.

[0042] Due to this force relationship, the core tensioning member 151 is maintained in a locked position by a compressive force directed toward the pivot shaft 154. The locking member 152 receives rotational moments in opposite directions from the abutment portion 27 and the core tensioning member 151, respectively, and is clamped between the abutment portion 27 and the core tensioning member 151, maintaining the locked position.

[0043] Here, when a force is generated that increases the distance between the housings, a force in the F1 direction (hereinafter also referred to as a separating force F1) is applied from the image forming apparatus main body 1 to the hook portion 155. In this case, the separating force F1 acts as a compressive force on the core tension member 151 and is supported by the compressive rigidity of the core tension member 151. In other words, even when the separating force F1 is generated, the locking mechanism 150 maintains the locked state.

[0044] As described above, in the locked state, the hook portion 155 of the locking member 152 always comes into contact with the abutment portion 27 of the image forming apparatus main body 1. Therefore, the image forming apparatus main body 1 and the extended feeding unit 100 are locked together without any gap. At this time, the force separating the image forming apparatus main body 1 and the extended feeding unit 100 (separating force F1) acts in the compressive direction on the tensioning member 151, so the locking strength is strong and the stability of the entire apparatus can be improved.

[0045] Furthermore, the abutment portion 27 is a part of the left side plate 31 and the right side plate 32, which are made of a conductive material such as metal. The locking member 152, the pivot shaft 153, the left side plate 131, and the right side plate 132 are also made of a conductive material such as metal. Because the locking member 152 always comes into contact with the abutment portion 27, the left side plate 31 and the right side plate 32 of the image forming apparatus main body 1 and the left side plate 131 and the right side plate 132 of the extended feeding unit 100 are electrically connected via the locking mechanism 150. Therefore, electrical conduction between the housings is possible without providing a separate earth.

[0046] [Unlocked] Next, the locking mechanism 150 when the extended feeding unit 100 is alone will be described with reference to Figure 10. When the image forming apparatus main body 1 is not connected to the extended feeding unit 100, the force (F1 described above) that holds the tensioning member 151 and the locking member 152 in a position corresponding to the locked state does not act. In this case, the tensioning member 151 and the locking member 152 are biased by their own weight toward a position corresponding to the unlocked state. Therefore, when only the extended feeding unit 100 is present, the locking mechanism 150 always waits in a position corresponding to the unlocked state.

[0047] [Transition from locked to unlocked state] When the image forming apparatus main body 1 is connected to the extended feeding unit 100, the operation of transitioning the locking mechanism 150 from the locked state shown in Fig. 6 to the unlocked state shown in Fig. 8 will be described. The cases when there is no resistance to the movement of the locking member 152 and when there is resistance to the movement of the locking member 152 will be described.

[0048] (When there is no resistance to the movement of the locking member) When there is no resistance to the movement of the locking member 152, if the user operates the tensioning member 151 to rotate it in the clockwise direction R1 in the locked state shown in Figure 6, the locking member 152 will rotate clockwise due to its own weight, resulting in a transition to the unlocked state shown in Figure 8.

[0049] (When there is resistance to the movement of the locking member) When there is resistance to the movement of the locking member 152, if the user operates the core tensioning member 151 to rotate in the clockwise direction R1 in the locked state of Figure 6, only the core tensioning member 151 will rotate, resulting in a transition to the intermediate state of Figure 7. The intermediate state is a state in which the core tensioning member 151 and the locking member 152 are separated, while the hook portion 155 of the locking member 152 remains in contact with the contact portion 27 of the main body frame 30. When the core tensioning member 151 is rotated further clockwise, the core tensioning member 151 pulls the link member 156, and the link member 156 pulls the locking member 152. As a result, the state transitions to the unlocked state shown in Figure 8. Resistance to the movement of locking member 152 is expected to occur when a sticky foreign substance such as grease gets between abutting portion 27 and hook portion 155, or when sliding resistance between abutting portion 27 and hook portion 155 increases, generating a force that maintains contact between abutting portion 27 and hook portion 155. With this configuration, even if there is resistance to the movement of locking member 152, the operating force of core tension member 151 can be transmitted to locking member 152, ensuring a transition to the unlocked state shown in Figure 8.

[0050] [Transition from unlocked to locked state] Next, the operation of transitioning from the unlocked state shown in FIG. 8 to the locked state shown in FIG. 6 will be described. In the unlocked state of FIG. 8, the operating unit 159 is used to rotate the core tension member 151 counterclockwise R2. The locking member 152 rotates counterclockwise along with the rotating core tension member 151, and the locking mechanism 150 transitions to the locked state shown in FIG. 6. In the locked state, the hook portion 155 of the locking member 152 comes into contact with the abutment portion 27 of the image forming apparatus main body 1. As described above, the hook portion 155 always comes into contact with the abutment portion 27. This allows the devices to be held without any gaps, and the core tension member 151 receives the force that would separate the devices via the locking member 152, firmly maintaining the connection between the devices and further improving the stability of the entire device.

[0051] In this way, the locking mechanism 150 is maintained in a locked state as follows: by a repulsive force exerted from the main body frame 30 on the hook portion 155 when the hook portion 155 abuts against the main body frame 30, and by a force exerted from the core tensioning member 151 to the locking member 152 when the core tensioning member 151 abuts against the locking member 152. Furthermore, the locking mechanism 150 is maintained in an unlocked state by the weight of the locking member 152 and the core tensioning member 151 when the hook portion 155 moves away from the main body frame 30 and the core tensioning member 151 moves away from the locking member 152.

[0052] Furthermore, the locking mechanism 150 is placed in a locked state when the abutting portion 151a abuts against the abutting portion 152a and the locking member 152 rotates in a predetermined direction (counterclockwise) of the rotation shaft 153, causing the hook portion 155 to abut against the main body frame 30. The locking mechanism 150 is placed in an unlocked state when the abutting portion 151a moves away from the abutting portion 152a and the locking member 152 rotates in a direction opposite to the predetermined direction of the rotation shaft 153 (clockwise), causing the hook portion 155 to move away from the main body frame 30. In the unlocked state, the hook portion 155 protrudes upward from the upper surface of the frame 130 in the vertical direction.

[0053] Furthermore, the locking member 152 and the main body frame 30 are formed of a conductive member, connecting the locking housing and the locked housing. When the locking member 152 moves or rotates to a position corresponding to the locked state, the locking housing and the locked housing become conductive. In the locked state, the hook portion 155 abuts against the main body frame 30, electrically connecting the main body frame 30 and the frame 130 via the locking member 152.

[0054] Furthermore, in the first embodiment, an example in which there are two locking mechanisms 150 is shown, but a configuration in which locking mechanisms 150 are added in one or two locations on all four sides excluding the front left and rear right may also be used. Furthermore, in the first embodiment, the core tension member 151 and the locking member 152 are biased by their own weight into a position corresponding to the unlocked state. As a result, when connecting devices, the locking member waits in a position corresponding to the unlocked state without requiring user operation. Furthermore, a link member 156 connecting the core tension member 151 and the locking member 152 is configured to reliably transition to the unlocked state. These configurations may also be configured so that the core tension member 151 and the locking member 152 are biased into the unlocked state by the elastic force of a spring or the like. In other words, the locking member 152 may be configured to move or rotate into a position corresponding to the unlocked state by an elastic member such as a spring.

[0055] The configuration of the locking mechanism 150 described above is the same for the locking mechanism of the extended feeding unit 200 and the locking mechanism of the caster-equipped base 500. Here, only the locking mechanism 150 for locking the extended feeding unit 100 to the image forming apparatus main body 1 will be described as a representative, and descriptions of the locking mechanisms of the extended feeding unit 200 and the caster-equipped base 500 will be omitted.

[0056] As described above, according to the first embodiment, it is possible to improve the stability of the entire device when two or more devices are connected together, and also improve usability. [Example]

[0057] [Connection method using locking mechanism] Example 2 will be described using Figures 11 and 12. Components similar to those in Example 1 are given the same reference numerals and will not be described again. Figure 11 shows the locked state of the locking mechanism 250 and the direction of the applied force (F3). Figure 12 shows the unlocked state of the locking mechanism 250. The locking member 252 has an abutment portion 252a that abuts against the core tensioning member 251 at the end opposite the hook portion 155. The core tensioning member 251 has a rail portion 251b, an abutment portion 251a that abuts against the abutment portion 252a of the locking member 252 at the end opposite the rail portion 251b, a slope portion 251c, and an operating portion (not shown). The rail portion 251b guides the parallel movement of the core tensioning member 251. As the core tensioning member 251 moves along the rail portion 251b, the second abutment portion 251a comes into contact with or moves away from the first abutment portion 252a. The core tensioning member 251 is mounted on the frame 130 and is configured to be able to move parallel to the arrow directions X1 and X2 in Figures 11 and 12. The core tensioning member 251 and the locking member 252 are biased by their own weight into a position corresponding to the unlocked state.

[0058] (locked state) First, the forces acting on the locking mechanism 250 in the locked state will be described with reference to FIG. 11. In FIG. 11, F1 and F3 indicate the directions of forces acting on the locking mechanism 250 in the locked state. The hook portion 155 makes contact by slightly deforming the abutment portion 27. As a result, a repulsive force F1 in the direction of F1 acts on the hook portion 155. This repulsive force F1 acts as a moment that rotates the locking member 252 in the clockwise direction M3 in FIG. 11. The moment that rotates the locking member 252 in the clockwise direction M3 is transmitted to the core tensioning member 251 in contact with the locking member 252 as a force in the direction of F3 (hereinafter referred to as force F3). Here, the directions X1 and X2 in which the core tensioning member 252 can move in parallel and the direction of the force (-F3) acting from the locking member 252 to the core tensioning member 251 are approximately perpendicular to each other. Here, "approximately perpendicular" includes cases where the directions are strictly perpendicular and also cases where the directions are considered to be substantially perpendicular. Therefore, the force acting from the locking member 252 to the core tensioning member 251 acts as a compressive force on the core tensioning member 252 and is supported by the compressive rigidity of the core tensioning member 252. At this time, the locking member 252 receives a reaction force of the compressive force F3 from the core tensioning member 251, which acts as a moment to rotate it in the counterclockwise direction M4 in Figure 11.

[0059] Due to the relationship described above, the core tension member 251 is maintained in the locked position by the compressive force F3. The locking member 252 receives rotational moments in opposite directions from the abutment portion 27 and the core tension member 251, and is clamped between the abutment portion 27 and the core tension member 251, maintaining the locked position. If a force is generated that increases the distance between the housings, a separating force F1 in the F1 direction acts on the hook portion 155 from the image forming apparatus main body 1. In this case, the separating force F1 acts on the core tension member 251 as a compressive force F3 and is supported by the compressive rigidity of the core tension member 251.

[0060] (Transition between locked and unlocked states) Next, we will explain the operation of transitioning the locking mechanism 250 from the locked state shown in Figure 11 to the unlocked state shown in Figure 12. In the locked state of Figure 11, the user translates the core tensioning member 251 in the direction of the arrow X1 in Figure 11. When the core tensioning member 251 translates in the direction of the arrow X1, the abutting portion 251a of the core tensioning member 251 that was abutting against the abutting portion 252a of the locking member 252 moves, and there is no longer a portion that supports the abutting portion 252a. This state is expressed as the core tensioning member 251 being retracted. When the core tensioning member 251 is retracted, the locking member 252 rotates clockwise under its own weight, transitioning to the unlocked state shown in Figure 12.

[0061] The operation of transitioning the locking mechanism 250 from the unlocked state shown in FIG. 12 to the locked state shown in FIG. 11 will now be described. In the unlocked state shown in FIG. 12, the user operates the core tensioning member 251 to move it parallel to the arrow direction X2 in FIG. 12. The locking member 252 rotates counterclockwise along the inclined surface 251c of the moving core tensioning member 251, transitioning the locking mechanism 250 to the locked state shown in FIG. 11. At this time, the locking member 252 is sandwiched between the abutting portion 27 and the core tensioning member 151, maintaining the locked state. Note that the inclined surface 251c of the core tensioning member 251 is formed linearly, but it may be formed curved, for example, as long as it does not interfere with the rotation of the locking member 252. In the locked state shown in FIG. 11, the repulsive force from the abutting portion 27 and the separating force between the housings are supported by the compressive rigidity of the core tensioning member 251. This type of locking mechanism 250 also achieves the same effects as in Example 1.

[0062] In this way, the locking mechanism 250 is maintained in a locked state as follows: by a repulsive force exerted from the main body frame 30 on the hook portion 155 when the hook portion 155 abuts against the main body frame 30, and by a force exerted from the core tensioning member 251 to the locking member 252 when the core tensioning member 251 abuts against the locking member 252. Furthermore, the locking mechanism 250 is maintained in an unlocked state by the weight of the locking member 252 when the hook portion 155 moves away from the main body frame 30 and the core tensioning member 251 moves away from the locking member 252.

[0063] Furthermore, the locking mechanism 250 is placed in a locked state when the abutting portion 251a abuts against the abutting portion 252a and the locking member 252 rotates in a predetermined direction (counterclockwise) of the rotation shaft 153, causing the hook portion 255 to abut against the main body frame 30. The locking mechanism 250 is placed in an unlocked state when the abutting portion 251a moves away from the abutting portion 252a and the locking member 252 rotates in a direction opposite to the predetermined direction of the rotation shaft 153 (clockwise), causing the hook portion 155 to move away from the main body frame 30.

[0064] As described above, according to the second embodiment, it is possible to improve the stability of the entire device when two or more devices are connected together, and also improve usability. [Example]

[0065] [Connection method using locking mechanism] Embodiment 3 will be described using Figures 13 and 14. Note that the same components as those in Embodiment 1 are assigned the same reference numerals and their description will be omitted. Figure 13 shows the locked state of locking mechanism 350, and Figure 14 shows the unlocked state of locking mechanism 350. Locking mechanism 350 is made up of a tension member 351 and a pivot shaft 354 mounted on image forming apparatus main body 1, which is the locked side housing, and a locking member 352 and a pivot shaft 153 mounted on extended feeding unit 100, which is the locking side housing.

[0066] The second member, or core tension member 351, has a rotation shaft 354, or third rotation shaft, and rotation around the rotation shaft 354 causes a contact portion 351a, or second contact portion, to come into contact with or move away from a contact portion 352a, or first contact portion. More specifically, the rotation shafts 354 are mounted on the left and right side plates 31 and 32 of the image forming apparatus main body 1, and the core tension member 351 is supported on the rotation shafts 154. The rotation shafts 153 are mounted on the left and right side plates 131 and 132 of the extended feeding unit 100, and a locking member 352 is supported on the rotation shafts 153. The locking member 352 has a contact portion 352a, which abuts against the core tension member 351, at the end opposite to the end that abuts against the contact portion 27 of the hook portion 155. The core tension member 351 has an abutment portion 351a at the end opposite the pivot shaft 354 that abuts against the abutment portion 352a of the locking member 352. The abutment portion 351a is arc-shaped. The core tension member 351 has an operating portion (not shown) that can be operated by the user. The core tension member 351 and the locking member 352 are biased by their own weight into a position that corresponds to the unlocked state.

[0067] (locked state) In the locked state shown in Figure 13, the repulsive force from the abutment portion 27 and the separating force between the housings are supported by the compressive rigidity of the core tension member 351, and the locking member 352 is clamped between the abutment portion 27 and the core tension member 351, maintaining a posture corresponding to the locked state.

[0068] (Transition between locked and unlocked states) Next, we will explain the operation of transitioning the locking mechanism 350 from the locked state shown in Figure 13 to the unlocked state shown in Figure 14. In the locked state of Figure 13, the user operates the core tensioning member 351 to rotate it counterclockwise. When the core tensioning member 351 rotates counterclockwise, the abutment portion 351a of the core tensioning member 351 that was abutting against the abutment portion 352a of the locking member 352 moves, and there is no longer a portion supporting the abutment portion 352a. This state is expressed as the core tensioning member 351 being retracted. When the core tensioning member 351 is retracted, the locking member 352 rotates clockwise due to its own weight. As a result, the state transitions to the unlocked state shown in Figure 14.

[0069] The operation of transitioning the locking mechanism 350 from the unlocked state shown in Figure 14 to the locked state shown in Figure 13 will now be described. In the unlocked state of Figure 14, the core tensioning member 351 is operated to rotate clockwise. The locking member 352 rotates counterclockwise along with the rotating core tensioning member 351, and the locking mechanism 350 transitions to the locked state shown in Figure 13. Here, the abutment portion 351a of the core tensioning member 351, which is the part of the core tensioning member that comes into contact with the locking member 352, is arc-shaped, and its center coincides with the rotation axis 154. Note that, although the abutment portion 351a of the core tensioning member 351 is formed in an arc-shape, it is not limited to this shape and may have any shape as long as it does not interfere with the rotation of the locking member 352.

[0070] In the third embodiment, the configuration has been described in which the core tension member 351 has an operating part, but it is also possible to configure the core tension member 351 and the locking member 352 both to have operating parts. This type of locking mechanism 350 also provides the same effects as the first embodiment.

[0071] As described above, according to the third embodiment, it is possible to improve the stability of the entire device when two or more devices are connected together, and also improve usability. [Explanation of symbols]

[0072] 1 Image forming device main body 30 Main frame 100 Extended Feeding Unit 130 frames 150 Locking mechanism 151 Core tension member 152 Locking member 155 Hook part

Claims

1. a first device having a first housing; a second device having a second housing; an image forming system for forming an image on a recording material, the image forming system including: a locking mechanism that switches between a locked state in which the first device and the second device are locked and a released state in which the locked state is released, The locking mechanism is a first member provided on the second housing and having a hook portion that is in contact with the first housing or spaced apart from the first housing; a second member that abuts against the first member to bring the hook portion into contact with the first housing and moves away from the first member to move the hook portion away from the first housing; and the locked state is maintained by a repulsive force exerted from the first housing to the hook portion when the hook portion abuts against the first housing, and a force exerted from the second member to the first member when the second member abuts against the first member, An image forming system characterized in that the released state is maintained by the weight of the first member when the hook portion moves away from the first housing and the second member moves away from the first member.

2. the first member has a first rotation shaft and a first abutment portion that is provided on an opposite side of the first rotation shaft from the hook portion and abuts against the second member in the locked state, the second member has a second abutment portion that abuts against the first abutment portion in the locked state, The locking mechanism is the second abutment portion abuts against the first abutment portion, and the first member rotates in a predetermined direction about the first rotation shaft, causing the hook portion to abut against the first housing, thereby entering the locked state; The image forming system of claim 1, characterized in that the second abutment portion moves away from the first abutment portion, and the first member rotates in a direction opposite to the specified direction of the first rotation axis, causing the hook portion to move away from the first housing, thereby entering the released state.

3. 3. The image forming system according to claim 2, wherein the second member has a second rotation axis, and the second contact portion contacts or moves away from the first contact portion by rotating around the second rotation axis.

4. The second contact portion has an arc shape, 4. The image forming system according to claim 3, wherein the direction of the force exerted from the first member to the second member is toward the center of the second rotation shaft.

5. The image forming system according to claim 4, characterized in that the locking mechanism has a link member having one end provided near the first abutment portion of the first member and the other end provided near the second abutment portion of the second member, which transmits movement of the second member to the first member.

6. a rail portion that guides the parallel movement of the second member; 3. The image forming system according to claim 2, wherein the second member moves along the rail portion so that the second contact portion comes into contact with the first contact portion or moves away from the first contact portion.

7. 7. The image forming system according to claim 1, wherein the second member is provided in the second housing.

8. 3. The image forming system according to claim 2, wherein the second member is provided in the first housing.

9. 9. The image forming system according to claim 8, wherein the second member has a third rotation axis, and the second contact portion contacts or moves away from the first contact portion by rotating around the third rotation axis.

10. the first member, the first housing, and the second housing are conductive members, 10. The image forming system according to claim 1, wherein in the locked state, the hook portion abuts against the first housing, thereby electrically connecting the first housing and the second housing via the first member.

11. 11. The image forming system according to claim 1, wherein the hook portion protrudes upward from an upper surface of the second housing in the up-down direction in the released state.

Images