JP6497945B2 - Position holding mechanism - Google Patents

Description

  The present invention relates to a position holding mechanism that holds a movable housing at a predetermined position.

  Conventionally, in a configuration including one housing and another housing that moves relative to the housing, various configurations have been proposed that hold the position of the other housing that moves at a predetermined position. ing. For example, a sheet conveying apparatus has been proposed that includes a first door that opens and closes with respect to a printer main body, and a reversing path guide that can be opened and closed with respect to the first door (see Patent Document 1). In this sheet conveying apparatus, the first door and the reverse path guide are connected by a toggle spring and a link portion, the reverse path guide is held in the open position, and the reverse path guide is moved along with the closing operation of the first door. It is configured to be closed.

  In addition, in a configuration in which the drawer unit provided so as to be able to be pulled out with respect to the housing is held at a predetermined position, a slide rail is provided with a step or a depression in the gravity direction, or a drawer unit is attracted by a magnet or the like It has been known.

JP 2012-012170 A

  However, the configuration described in Patent Document 1 described above and other configurations for holding the position are provided with an auxiliary mechanism such as a spring, a link, or a magnet, and there is a problem from the viewpoint of downsizing and cost reduction of the device. there were.

  Further, in a configuration in which a biasing member such as a spring is provided, the casing may move vigorously against the user's intention due to the biasing force. In a configuration in which a step or depression is provided on the slide rail, a large operating force is required when pulling up the housing (drawer unit) from the step or depression. Therefore, such a configuration has a problem from the viewpoint of operability.

  Accordingly, an object of the present invention is to provide a position holding mechanism having a simple configuration and good operability.

In the position holding mechanism, the present invention provides a first casing, a second casing that is movable with respect to the first casing, the first casing, and the second casing. A connecting portion provided on any one of the bodies and slidably connected to a connected portion provided on the other of the first casing and the second casing, and The connecting portion includes a first hole portion and a third hole portion whose length in the width direction perpendicular to the sliding direction in which the connected portion slides is longer than the length of the connected portion in the width direction, and the covered portion. and the width direction of the second hole portion shorter than the length of the connecting portion, are continuously formed, the have a slide hole which the connecting portion is slidably supported, said second housing, said When the connected portion is located in the first hole, the first casing is connected to the connected portion and the connected portion. The second hole portion is disposed between the first hole portion and the third hole portion in the sliding direction, and extends parallel to the sliding direction and slides on the connected portion. The third hole has a second edge that extends in parallel with the sliding direction and is longer than the first edge .

Further, according to the present invention, in the position holding mechanism, the first casing, the second casing provided to be movable with respect to the first casing, the first casing, and the second casing A connecting portion provided in one of the housings and provided with a slide hole, and a connected portion provided in the other of the first housing and the second housing and connected to the slide hole. And the connecting portion and the covered portion so that the to-be-connected portion extends along the longitudinal direction of the slide hole as the second housing moves relative to the first housing. The connecting portion moves relatively, and the slide hole of the connecting portion has the first hole portion and the third hole portion, and the length in the width direction orthogonal to the longitudinal direction is the width direction of the connected portion. shorter than the length, and have a, a second hole portion shorter than a length of the first hole portion and the width direction of the third hole portion, the second The housing is held by the first housing via the connecting portion and the connected portion when the connected portion is located in the first hole portion, and the second hole portion is The first edge portion is disposed between the first hole portion and the third hole portion in the longitudinal direction, extends in parallel with the longitudinal direction, and slides on the coupled portion, and The hole has a second edge that extends parallel to the longitudinal direction and is longer than the first edge .

  According to this invention, the to-be-connected part provided in either one of the 1st housing | casing and the 2nd housing | casing is supported by the slide hole of a connection part. The slide hole has a first hole whose length in the width direction is longer than a length in the width direction of the connected portion, and a second hole that is shorter than the length in the width direction of the connected portion. . Therefore, for example, the connected portion is held in the second hole portion, so that either the first housing or the second housing can be connected with a simple configuration without providing an auxiliary mechanism such as a spring or a magnet. It can be held in place. Further, since the casing does not move suddenly by the spring and a large operating force for pulling up the casing against gravity is not required, the operability can be improved.

1 is an overall schematic diagram illustrating a printer according to a first embodiment. The side view which shows the door unit of the state which the inner door closed. The side view which shows the door unit in the state where the inner door was opened. The enlarged view which expanded and showed the broken-line part of FIG. The perspective view which shows a connection member. Explanatory drawing explaining the dimension of a slide hole and a connection boss | hub. Explanatory drawing explaining the movement of the connection boss | hub which slides within the slide hole. Explanatory drawing explaining the dimension of each part of a slide hole. It is a figure which shows the 1st modification concerning 1st Embodiment, Comprising: The side view which shows having reversed the attachment structure of the connection member. The perspective view which shows the slide unit of the 2nd modification based on 1st Embodiment. Explanatory drawing explaining a motion of a cassette and a connection boss | hub. It is a figure which shows the 3rd modification which concerns on 1st Embodiment, Comprising: The side view which shows having comprised the boss | hub and the connection boss | hub in the cross-sectional C shape. It is a figure which shows the 3rd modification which concerns on 1st Embodiment, Comprising: The side view which shows having comprised the boss | hub and the connection boss | hub in the cross-sectional rectangular shape. The side view showing the door unit in the state where the inner door concerning a 2nd embodiment was closed. The side view which shows the door unit in the state where the inner door was opened. The enlarged view which expanded and showed the broken-line part of FIG. Explanatory drawing explaining the dimension of each part of a slide hole. The side view which shows the connection member which concerns on 3rd Embodiment.

  A printer 100 (image forming apparatus) according to an embodiment of the present invention is an electrophotographic laser beam printer that forms toner images of four colors. As illustrated in FIG. 1, the printer 100 includes a sheet feeding unit 110 that feeds stacked sheets and an image forming unit 140 that forms an image to be transferred to the sheet. In addition, the printer 100 includes a fixing device 150 that fixes an image transferred on a sheet, and a door unit 189 (position holding mechanism) that can be opened and closed with respect to the apparatus main body 100A of the printer 100. .

  When an image formation command is output to the printer 100, an image forming process by the image forming unit 140 is started based on image information input from an external computer or the like connected to the printer 100. The image forming unit 140 includes an exposure device 142 and four process cartridges Y, M, C, and Bk that form images of four colors of yellow, magenta, cyan, and black. The four process cartridges Y, M, C, and Bk have the same configuration except that the colors of images to be formed are different. Only the image forming process of the process cartridge Y will be described, and the process cartridges M, C, and Bk will be described. Description is omitted.

  The exposure device 142 irradiates the photosensitive drum 141 of the process cartridge Y with laser light based on the input image information. At this time, the photosensitive drum 141 is charged in advance by a charging roller (not shown), and an electrostatic latent image is formed on the photosensitive drum 141 when irradiated with laser light. Thereafter, the electrostatic latent image is developed by the developing unit 143, and a yellow toner image is formed on the photosensitive drum 141.

  Similarly, magenta, cyan, and black toner images are formed on the photosensitive drums of the process cartridges M, C, and Bk. The toner images of the respective colors formed on the photosensitive drums are transferred to the intermediate transfer belt 145 driven in the A direction by the primary transfer rollers 144Y, 144M, 144C, and 144Bk, and are transferred to the secondary transfer unit 130 by the intermediate transfer belt 145. Be transported. The secondary transfer unit 130 is configured by a nip between the secondary transfer inner roller 131 and the secondary transfer outer roller 132 facing each other, and a predetermined pressure and electrostatic load bias are applied to the sheet S by the nip. The image can be transferred. Note that the image forming process for each color is performed at a timing at which the image is superimposed on the upstream toner image primarily transferred onto the intermediate transfer belt 145.

  In parallel with the above-described image forming process, the sheets S stored in the cassette 6 of the sheet feeding unit 110 are separated one by one by a feeding separation unit (not shown) and conveyed toward the registration roller pair 120. Is done. In the present embodiment, only one cassette 6 is provided. However, a plurality of cassettes for stacking sheets of different sizes are provided, and sheets are fed according to the sheet size selected from the plurality of cassettes. You may send it.

  The skew transfer is corrected by the registration roller pair 120, and the first surface (front surface) of the sheet S conveyed at a predetermined conveyance timing is subjected to intermediate transfer by an electrostatic load bias applied to the secondary transfer unit 130. A full color toner image on the belt 145 is transferred. The sheet S on which the toner image is transferred is given predetermined heat and pressure in the fixing device 150, and the toner is melted and fixed (fixed). For the sheet S that has passed through the fixing device 150, a conveyance path through which the sheet is conveyed is selected by the first switching member F1, the second switching member F2, and the third switching member F3.

  The sheet guided to the first discharge roller pair 160 by the first switching member F1 is discharged to the first discharge tray 170. The sheet S guided to the second discharge roller pair 161 by the first switching member F1 and the second switching member F2 is discharged to the second discharge tray 171. Further, the sheet S guided to the second discharge roller pair 161 is driven in the reverse direction by the second discharge roller pair 161 and is guided to the third discharge roller pair 162 by the third switching member F3. It is discharged to 184.

  When images are formed on both sides of the sheet S, the sheet S on which the image is formed on the first side is guided to the double-sided path 164 by the third switching member F3, and the registration roller by the double-sided roller pair 163 and the like. Transported to pair 120. Then, a toner image is formed on the second surface (back surface) of the sheet S by the secondary transfer unit 130. The sheet S on which the toner image is fixed on the sheet by the fixing device 150 and the image is formed on the first surface and the second surface is selected as the first discharge tray 170, the second discharge tray 171 and the third discharge tray 184. Are exhausted.

  Next, the door unit 189 which is a main part of the present invention will be described in detail. As shown in FIGS. 1 and 2, the door unit 189 includes an outer door 190 that is rotatable (openable and closable) with respect to the apparatus main body 100A around a rotation shaft 192, and a shaft (not shown). The inner door 191 is provided at the center so as to be rotatable (openable and closable) with respect to the outer door 190. The outer shape of the door unit 189 is indicated by a broken line portion in FIG. 1, and the transfer conveyance path 129 (see FIG. 1) is opened by opening the outer door 190 (first housing) in the B direction shown in FIG. For example, a sheet that is opened and jammed in the transfer conveyance path 129 can be taken out.

  As shown in FIG. 3, the inner door 191 (second housing) is opened in the B2 direction away from the outer door 190 to open the double-sided path 164 (conveyance path). As a result, it is possible to easily access the double-sided path 164 that is difficult to jam by simply opening the outer door 190.

  As shown in FIG. 4, the outer door 190 is provided with a boss 3 that extends in a direction orthogonal to the opening / closing direction of the outer door 190. The inner door 191 is provided with a connecting boss 4 (connected portion) that extends parallel to the axial direction of the boss 3. FIG. 4 is an enlarged view of the broken line portion of FIG.

  The door unit 189 has an engagement hole 11 that engages with the boss 3 of the outer door 190, and includes a connection member 10 (connection portion) that is rotatably supported by the boss 3. A slide hole 12 is formed in the central portion of the connecting member 10 so that the connecting boss 4 of the inner door 191 is slidably supported. The connecting member 10 is connected to the inner portion 191 via the connecting boss 4 and the slide hole 12. The door 191 is slidably connected. That is, as the inner door 191 moves with respect to the outer door 190, the connecting member 10 and the connecting boss 4 relatively move so that the connecting boss 4 extends along the longitudinal direction of the slide hole 12. The slide hole 12 is formed extending in the longitudinal direction of the connecting member 10, and the connecting member 10 is formed of an elastic member such as resin.

  As shown in FIGS. 5 and 6, the connecting member 10 has a support portion 13 integrally formed in the vicinity of the engagement hole 11, and the support portion 13 is formed with respect to a portion where the engagement hole 11 is formed. They are arranged with a predetermined clearance f. A protruding protrusion 13 a is provided at the tip of the support portion 13.

  As shown in FIG. 5, the slide hole 12 has a different hole shape in the sliding direction in which the connecting boss 4 slides. The first hole 12a and the second hole 12c are distinguished for convenience by the difference in the hole shape. And the 3rd hole 12b is formed continuously. The first hole 12a (first hole) and the third hole 12b (first hole) are respectively formed at both ends of the slide hole 12, and the second hole 12c (second hole) is formed at both ends of the slide hole 12. It is formed between. The third hole 12b is provided close to the boss 3 with respect to the first hole 12a and the second hole 12c, and is longer in the sliding direction than the first hole 12a and the second hole 12c. .

  Next, the dimensional relationship between the slide hole 12 and the connecting boss 4 will be described. As shown in FIG. 6, the connecting boss 4 is formed in a cylindrical shape, and the length φD in the width direction perpendicular to the sliding direction (longitudinal direction of the slide hole 12) coincides with the length of the outer diameter. The lengths a and b in the width direction of the first hole 12a and the third hole 12b of the slide hole 12 are set to be substantially equal to or longer than the length φD of the connecting boss 4 in the width direction. (A ≧ φD, b ≧ φD).

Further, the length c of the slide hole 12 in the width direction of the second hole 12c is set to be smaller than the length φD of the connecting boss 4 in the width direction (c <φD). Therefore, between the respective lengths a, c, b in the width direction of the first hole 12a, the second hole 12c, and the third hole 12b of the slide hole 12, and the length φD in the width direction of the connecting boss 4. The following relational expression holds.
a ≧ φD> c (1)
b ≧ φD> c (2)

  In the present embodiment, the length a in the width direction of the first hole 12a and the length c in the width direction of the third hole 12b are set to be substantially the same, but the above-described relational expression (1) ( Any value may be set as long as 2) is established.

  Next, an operation when the inner door 191 is opened and closed with respect to the outer door 190 will be described. As shown in FIG. 7, the connecting boss 4 of the inner door 191 moves in the slide hole 12 in accordance with the opening / closing operation of the inner door 191. Here, a position where the connecting boss 4 is located in the third hole 12b is a closed position H, a position where the connecting boss 4 is located in the first hole 12a is an open position K, and the connecting boss 4 is the first position. A position from the third hole 12b to the second hole 12c is defined as a holding start position J.

  In a state where the inner door 191 is closed by the outer door 190, the connecting boss 4 is located at a position close to the boss 3 at the closed position H. When the inner door 191 is gradually opened by the user, the connecting boss 4 moves from the position close to the boss 3 toward the holding start position J. At this time, since the connecting member 10 is provided so as to be rotatable with respect to the outer door 190 and slidable with respect to the inner door 191, the connecting boss 4 moves smoothly in the slide hole 12. Can do. Further, according to the relational expression (2) described above, the connecting boss 4 can slide within the slide hole 12 without generating a large sliding resistance, and the user's operating force can be reduced.

  Next, when the connecting boss 4 is located in the section from the holding start position J to the position immediately before the opening position K, the length c of the second hole 12c in the width direction is shorter than the length φD of the connecting boss 4; The boss 4 presses the connecting member 10. Thereby, an external force F acts on the connecting member 10 from the connecting boss 4. Then, the connecting member 10 is elastically deformed slightly in the direction of the arrow T (outward with respect to the slide hole 12), and the connecting boss 4 moves in the second hole 12c in a light press-fit state. At this time, a predetermined sliding resistance is generated in the connecting boss 4, and the inner door 191 can be held at a desired position by the sliding resistance.

  When the user opens the inner door 191 further, the connecting boss 4 reaches the opening position K, and the elastic deformation of the connecting member 10 is eliminated by the relational expression (1) described above. In a state where the connecting boss 4 is located at the open position K, the inner door 191 is opened to the maximum opening. The movement of the connecting boss 4 in the direction of the closing position H is regulated by the second hole 12c that has returned to the dimensional relationship of the relational expression (1) described above after the elastic deformation has been eliminated. Unless an external force equal to or greater than the sliding resistance is applied, the inner door 191 is held open.

  Moreover, the shape of the 1st hole 12a is formed so that the connection boss | hub 4 may be loosely fitted, and it can hold | maintain without backlash in the state which opened the inner door 191. Further, in a state where the connection boss 4 is located at the open position K, the movement of the connection boss 4 is restricted by the protrusion 13a of the support portion 13 coming into contact with the inner wall of the outer door 190, and the connection boss 4 is restricted to the first hole 12a. The connecting member 10 is prevented from being damaged by colliding with the end of the connector. Since the support portion 13 is provided with a predetermined clearance f, the support portion 13 is urged to be elastically deformed to prevent stress concentration on the connecting member 10 including the support portion 13 and to be damaged. It is configured to be difficult. In addition, you may comprise so that the opening of the inner door 191 may be controlled by receiving the connection boss | hub 4 with the inner wall of the 1st hole 12a, without providing the support part 13. FIG.

  Further, when the inner door 191 is closed, an external force equal to or greater than the predetermined sliding resistance in the second hole 12c is applied by the user in the closing direction of the inner door 191, so that the connecting boss 4 is opposite to the movement path described above. Move the route. Since the detailed operation when closing the inner door 191 is merely a process reverse to the operation when opening the inner door 191, the description thereof is omitted.

  As described above, in the present embodiment, it is possible to hold the inner door 191 with a simple configuration and at a low cost as compared with the conventional case where an auxiliary mechanism such as a spring or a magnet is provided. Further, in a state where the connecting boss 4 is located in the section from the holding start position J to the opening position K, the inner door 191 can be held at a desired position. Therefore, for example, when the space adjacent to the outer door 190 of the printer 1 is narrow, the inner door 191 is held at the holding start position J without opening the outer door 190 to the maximum opening degree, and jam processing is performed. be able to. Thereby, the opening degree of the inner door 191 can be set according to a condition, and usability can be improved.

  Moreover, since this Embodiment utilizes the elastic deformation of the connection member 10, the operation direction at the time of opening and closing the inner door 191 is only one direction. That is, there is no need to operate the housing in multiple directions, as in the configuration in which the slide rail is provided with a groove to hold the housing, and the housing does not move suddenly due to a biasing force such as a spring. Good properties.

  Furthermore, in this embodiment, the operating force and the holding function of the inner door 191 can be easily adjusted by changing the shape of the slide hole. This will be described below with reference to FIG. The length of the second hole 12c in the sliding direction is defined as the length w, and the difference between the lengths a and b of the first hole 12a and the third hole 12b in the width direction and the length c of the second hole 12c in the width direction. Is the difference t (a = b, a−c = t).

  Here, when the difference t is increased, the sliding resistance of the connecting boss 4 in the second hole 12c can be increased, and when the difference t is decreased, the sliding resistance can be decreased. That is, by adjusting the length of the difference t, the operation force when the user opens and closes the inner door 191 is minimized while maintaining the magnitude of the sliding resistance that can be held with the inner door 191 open. Can be easily set. Note that the magnitude of the sliding resistance that can be held with the inner door 191 opened is determined by the rotational moment caused by the weight of the inner door 191.

  Further, by increasing the length w, it is possible to lengthen the section in which the sliding load is generated in the second hole 12c, and it is possible to increase the redundancy with respect to the unexpected external force received when the inner door 191 is open. . On the other hand, by shortening the length w, it is possible to shorten the time during which the sliding load is generated, and to reduce the time during which the operation load is applied to the user who opens and closes the inner door 191. That is, by adjusting the length w, it is possible to easily perform the adjustment that minimizes the user's operation force while maintaining redundancy against the unexpected external force.

(First modification)
FIG. 9 shows a first modification of the door unit 189 in the present embodiment, and shows a configuration in which the attachment of the connecting member 10 described above to the outer door 190 and the inner door 191 is reversed. That is, the connecting member 10 is supported so as to be slidable with respect to the outer door 190 by engaging the boss 3 of the outer door 190 with the slide hole 12, and the connecting boss 4 and the engaging hole 11 of the inner door 191. Is engaged with the connecting boss 4 so as to be rotatable.

  In such a mounting configuration, the boss 3 slides in the slide hole 12 as the inner door 191 opens and closes, and the same effects as those described above with reference to FIGS. That is, if the connection member 10 is provided on one of the outer door 190 and the inner door 191 and the connection member 10 is slidably supported on the other door, the above-described effect can be obtained.

(Second modification)
The above-described configuration described with reference to FIGS. 1 to 9 exemplifies an opening / closing movement type position holding mechanism in which the other casing rotates (opens and closes) with respect to one casing, such as the outer door 190 and the inner door 191. However, the present invention is not limited to the open / close moving type, and may be, for example, a slide moving type configuration. An example of the slide movement type position holding mechanism is shown in FIG.

  As shown in FIG. 10, the slide unit 179 (position holding mechanism) includes a frame 5 that is a first housing and a second housing that is slidable (movable) in the P direction with respect to the frame 5. And a cassette 6 which is a body. In the printer 100 shown in FIG. 1, for example, the slide unit 179 can be applied to the cassette 5 (storage member) of the sheet feeding unit 110 in which the frame 5 is a frame of the apparatus main body 1A and the cassette 6 stores sheets. .

  As shown in FIG. 11, the slide unit 179 has a connecting member 10 that connects the frame 5 and the cassette 6. The connecting member 10 is supported by the frame 5 when the boss 3 of the frame 5 is engaged with the engaging hole 11, and is connected to the cassette 6 when the connecting boss 4 of the cassette 6 is engaged with the slide hole 12. On the other hand, it is slidably supported.

  When the connecting boss 4 is positioned in the first hole 12 a of the slide hole 12, the cassette 6 is held open, and when the connecting boss 4 is positioned in the second hole 12 b of the slide hole 12, the cassette 6 is held. Is closed. The connecting boss 4 moves in the same manner as in the above-described configuration described with reference to FIGS.

  In the slide movement type position holding mechanism, the connecting member 10 does not have to be supported rotatably with respect to the frame 5, and the connecting member 10 is fixed to the boss 3 of the frame 5. Also good.

(Third Modification)
1 to 8, the boss 3 and the connection boss 4 do not necessarily have a cylindrical shape. For example, as shown in FIG. 12, the boss 3 and the connecting boss 4 may be formed in a C-shaped cross section, or may be formed in a rectangular cross section as shown in FIG. That is, the connecting boss 4 may have any shape as long as it can move along the slide hole 12, and the boss 3 may have any shape as long as it can be connected to one housing. The effects of the present invention are not limited by the shapes of the boss 3 and the connecting boss 4.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the second embodiment, the connecting member 10 of the first embodiment is configured integrally with the outer door 190. About the structure similar to 1 embodiment, illustration is abbreviate | omitted or attaches | subjects the same code | symbol to a figure and demonstrates.

  As shown in FIGS. 14 and 15, the door unit 199 (position holding mechanism) is centered on an outer door 190 ′ that can be opened and closed with respect to the apparatus main body 100 </ b> A around a rotation shaft 192, and a shaft (not shown). And an inner door 191 that can be opened and closed with respect to the outer door 190. A connecting portion 10 ′ is integrally formed with the outer door 190 ′ (first housing).

  As shown in FIG. 16, a slide hole 12 is formed in the central portion of the connecting portion 10 ′ so that the connecting boss 4 of the inner door 191 is slidably supported. The connecting portion 10 ′ includes the connecting boss 4. And, it is slidably connected to the inner door 191 through the slide hole 12. The connecting portion 10 ′ is formed of an elastic member such as resin and has a rib portion 14 that is thick, so that the strength of the connecting portion 10 ′ is improved.

  Unlike the first embodiment, the slide hole 12 is formed in an arc shape along the rotation trajectory of the inner door 191, but the connecting boss 4 and the first holes 12a and second of the slide hole 12 are formed. The dimensional relationship in the width direction between the hole 12c and the third hole 12b is the same as that in the first embodiment. Therefore, the code | symbol which shows these dimensions is attached | subjected to FIG. 17, and description is abbreviate | omitted.

  Further, the action of the connecting boss 4 in the slide hole 12 based on the opening / closing operation of the inner door 191 is the same as that of the first embodiment, and has the same effect. In the present embodiment, since the connecting portion 10 ′ is formed integrally with the outer door 190 ′, the position of the inner door 191 can be maintained with a simpler configuration, and the cost can be reduced.

  In the present embodiment also, the features of the first to third modifications described in the first embodiment can be applied, and the above-described effects based on these features can be achieved.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The same configuration as that of the first embodiment will be described by omitting illustration or attaching the same reference numerals to the drawings. As shown in FIG. 18, in the connecting member 200 (connecting portion), the engaging hole 11 that engages with the boss 3 of the outer door 190 and the sliding hole 12 in which the connecting boss 4 of the inner door 191 is slidably supported. And are formed. A notch 15 is continuously formed at the end of the slide hole 12 opposite to the side close to the boss 3 (the first hole 12a side), and the notch 15 is connected in the width direction. The boss 4 is formed with a size smaller than the outer diameter. The dimensional relationship in the width direction between the connecting boss 4 and the first hole 12a, the second hole 12c, and the third hole 12b of the slide hole 12 is the same as that of the first embodiment.

  As described in the first embodiment, when the connecting boss 4 is positioned in the section from the holding start position J to the position immediately before the opening position K, the length c of the second hole 12c is greater than the length φD of the connecting boss 4. Therefore, an external force F acts on the connecting member 10 from the connecting boss 4 (see FIG. 6). Thereby, the connecting member 10 is elastically deformed minutely in the arrow T direction. At this time, the stress is generated most in the vicinity of the broken line portion G shown in FIG.

  In the present embodiment, since the notch 15 is provided in the connecting member 200, the place where the stress is generated can be shifted to the side far from the connecting boss 4. Thereby, the stress which generate | occur | produces by the elastic deformation of the connection member 200 can be reduced, and the improvement with respect to the crack etc. of the connection member 200 and the improvement of durability can be aimed at.

  Note that the notch 15 may be provided in the connecting portion 10 ′ of the second embodiment, and even in that case, the same effect can be obtained.

  In the first to third embodiments described above, only one second hole 12c (first hole) is provided in the slide hole 12, but a plurality of second holes 12c may be provided. For example, in order to securely hold the inner door 191 even in the closed position, another second hole 12c may be provided in the region of the third hole 12b. Further, either one of the first hole 12a and the second hole 12b may be omitted. For example, when the first hole 12a is omitted, the connection boss 4 can be held only by the second hole 12c. .

  In addition, if the slide hole 12 is formed by continuously forming the first hole 12a, the second hole 12b, and the third hole 12c, the first hole 12a, the second hole 12b, and the third hole 12c The order and arrangement are not limited.

  In the first to third embodiments described above, the lengths a and b in the width direction of the first hole 12a and the third hole 12b are set as shown in the relational expressions (1) and (2). Although it set larger than length φD of the width direction of the connection boss | hub 4, it is not limited to this. That is, if the movement of the connecting boss 4 is not hindered, the lengths a and b of the first hole 12a and the third hole 12b in the width direction may be set slightly smaller than the width φD of the connecting boss 4 in the width direction. Good. In this case, the length c in the width direction of the second hole 12c is set smaller than the lengths a and b in the width direction of the first hole 12a and the third hole 12b and the length φD in the width direction of the connecting boss 4. The

  In addition, the position holding mechanism of the present invention is not limited to an image forming apparatus such as a printer, a fax machine, or a multifunction machine, but may be various types having a second casing that is movable with respect to the first casing. Applicable.

4: connected portion (connecting boss), 5: first casing (frame), 6: storage member (cassette), 10, 200: connecting portion (connecting member), 10 ′: connecting portion, 12: slide hole , 12a: first hole (first hole), 12b: second hole (second hole), 12c: first hole (third hole), 15: notch, 100: image forming apparatus (printer) , 100A: apparatus main body, 164: transport path (double-sided path), 179: position holding mechanism (slide unit), 189, 199: position holding mechanism (door unit), 190, 190 ′: first casing (outer door) ), 191: second casing (inner door), a, c: length, φD: length, length of outer diameter

Claims (11)

A first housing;
A second housing movably provided with respect to the first housing;
Provided in one of the first casing and the second casing, and is slidable with respect to the connected portion provided in the other of the first casing and the second casing. And a connecting portion connected to
The connecting portion includes a first hole portion and a third hole portion whose length in the width direction perpendicular to the sliding direction in which the connected portion slides is longer than the length of the connected portion in the width direction; and a second hole portion shorter than a length of the width direction of the connecting portion, are continuously formed, the object connection portion have a slide hole which is slidably supported,
The second casing is held by the first casing via the connecting portion and the connected portion when the connected portion is located in the first hole portion,
The second hole portion is disposed between the first hole portion and the third hole portion in the sliding direction, and extends parallel to the sliding direction and slides on the connected portion. Have
The third hole has a second edge that extends parallel to the sliding direction and is longer than the first edge.
A position holding mechanism characterized by that. A first housing;
A second housing movably provided with respect to the first housing;
A connecting portion provided in any one of the first housing and the second housing, and having a slide hole;
A connected portion provided on the other of the first housing and the second housing and connected to the slide hole,
As the second casing moves with respect to the first casing, the connecting portion and the connected portion are relatively positioned so that the connected portion extends along the longitudinal direction of the slide hole. Go to
The slide hole of the connecting part has a first hole part and a third hole part, and the length in the width direction orthogonal to the longitudinal direction is shorter than the length in the width direction of the connected part, and the first hole parts and have a, a second hole portion shorter than a length of the width direction of the third hole portion,
The second casing is held by the first casing via the connecting portion and the connected portion when the connected portion is located in the first hole portion,
The second hole portion is disposed between the first hole portion and the third hole portion in the longitudinal direction, and extends in parallel with the longitudinal direction and slides on the coupled portion. Have
The third hole has a second edge that extends in parallel with the longitudinal direction and is longer than the first edge.
A position holding mechanism characterized by that. The connecting portion is elastically deformed outward with respect to the slide hole when the connected portion presses the second hole portion.
The position holding mechanism according to claim 1 or 2 . In the connecting portion, a notch for reducing stress generated by the elastic deformation is formed continuously to the slide hole.
The position holding mechanism according to claim 3 . The connected portion is formed in a cylindrical shape,
The length in the width direction of the connected portion is the length of the outer diameter.
The position holding mechanism according to any one of claims 1 to 4 , wherein the position holding mechanism is provided. The connecting portion is rotatably supported by the first housing.
The position holding mechanism according to any one of claims 1 to 5 , wherein: The connecting portion is formed integrally with the first housing.
The position holding mechanism according to any one of claims 1 to 5 , wherein: The second casing is provided so as to be rotatable with respect to the first casing.
Position holding mechanism according to any one of claims 1 7, characterized in that. The second casing is slidably provided with respect to the first casing.
Position holding mechanism according to any one of claims 1 7, characterized in that. The first housing is an outer door that can be opened and closed with respect to the apparatus main body of the image forming apparatus that forms an image on a sheet.
The second housing is an inner door that opens a sheet conveyance path by being moved in a direction away from the outer door.
The position holding mechanism according to claim 8 . The first casing is an apparatus main body of an image forming apparatus that forms an image on a sheet,
The second casing is a storage member that stores a sheet.
The position holding mechanism according to claim 9 .

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