Locking mechanism and image forming apparatus having the same

Abstract

The cover member (20) has: a fitting recess (26) that opens to one side in a direction orthogonal to the axis of the shaft member (31), receives the torsion coil spring (34) from the one side, and fits with the outer peripheral surface of the torsion coil spring (34); and a fixed portion (27a) for fixing one end portion of the torsion coil spring (34). The torsion coil spring (34) functions as a bearing member that rotatably supports both end portions of the shaft member (31) on the inner side surface of the coil in a state of being fitted in the fitting recess (26), exerts force on the hook member (32) to the locking side around the axis of the shaft member (31) by engaging with the hook member (32), and rotatably supports the shaft member (31).

Description

Technical Field

[0001] The present invention relates to a locking mechanism and an image forming apparatus having the locking mechanism. Background Technology

[0002] Typically, as a locking mechanism for a cover component that rotates around one end edge, a structure using a hook component is known (for example, see Patent Document 1). This locking mechanism includes a shaft component extending along an end edge opposite to one end edge of the cover component, and both ends are rotatably supported on the cover component. A hook component is integrally fixed to the shaft component, and the hook component has an engaging hook portion formed at its front end. When the cover is moved to the closed position, the engaging hook portion of the hook component engages with a locked portion located at a predetermined position. A force-applying component applies force to the hook component towards the locking side that engages the engaging hook portion with the locked portion. A manual operating part is provided on the cover component for releasing the locking mechanism. When the manual operating part is operated, the shaft component rotates towards the unlocking side against the force-applying component, releasing the engagement of the hook portion of the hook component with the locked portion. Both ends of the shaft component are supported on the cover component via bearing components.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-127997 Summary of the Invention

[0006] However, in the locking mechanism disclosed in Patent Document 1, the number of bearing components required for supporting the two ends of the shaft component increases, leading to an increase in cost.

[0007] The present invention is made in view of the relevant points, and its object is to reduce the number of parts and reduce product cost by making structural improvements in a locking mechanism that has a hook component that is rotatably and integrally fixed to a shaft component and a force-applying component that applies force to the hook component around the shaft component.

[0008] One aspect of the present invention relates to a locking mechanism comprising: a cover member capable of being opened and closed by rotation about one end edge; a shaft member extending along an end edge opposite to one end edge of the cover member, and rotatably supported at both ends of the cover member; a hook member integrally connected to the shaft member and having a locking hook portion formed at its front end; a locked portion for locking the cover member by engaging with the locking hook portion of the hook member when the cover member is moved to the closed position; a torsion coil spring for applying force to the hook member toward the locking side, i.e., the side where the locking hook portion engages with the locked portion; and a manual operation portion for disengaging the locking hook portion from the locked portion by manually rotating the shaft member when the cover member is in the closed position. The cover member comprises: a fitting recess opening toward a side orthogonal to the axis of the shaft member, receiving the torsion coil spring from that side and fitting with the outer peripheral surface of the torsion coil spring; and a fixed portion for fixing one end of the torsion coil spring. When the torsion coil spring is engaged with the locking part in the locking recess, it applies force to the locking part around the axis of the shaft part by engaging with the hook part, and rotatably supports both ends of the shaft part on the inner side of the coil.

[0009] Another aspect of the present invention relates to an image forming apparatus comprising: the locking mechanism described above; a main body for being disposed of by the engaging portion; and an image forming unit for forming an image on a recording medium.

[0010] Invention Effects

[0011] According to the present invention, in a locking mechanism comprising a hook member rotatably and integrally fixed to a shaft member and a force-applying member that applies force to the hook member around the shaft member, the number of parts can be reduced and the product cost can be lowered. Attached Figure Description

[0012] Figure 1 This is a perspective view showing the external appearance of an image forming apparatus having a locking mechanism according to one embodiment of the present invention.

[0013] Figure 2 This is a perspective view of the image forming apparatus showing the state of the main cover being opened.

[0014] Figure 3 This is a three-dimensional view of the switch cover from the surface side.

[0015] Figure 4 This is a 3D view of the switch cover from the back side.

[0016] Figure 5 yes Figure 4 VV-line sectional view.

[0017] Figure 6 yes Figure 4 Sectional view along line VI-VI.

[0018] Figure 7 It is an enlarged representation Figure 4 An enlarged view of part VII.

[0019] Figure 8 yes Figure 7 View in direction VIII.

[0020] Figure 9 yes Figure 7 The IX direction view.

[0021] Figure 10 yes Figure 7 The X-direction view. Detailed Implementation

[0022] Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment.

[0023] Figure 1 This is a perspective view showing the external appearance of an image forming apparatus 1 equipped with a locking mechanism according to one embodiment of the present invention. The image forming apparatus 1 is a multifunction image forming apparatus (multifunction printer) that, in addition to printing, also has scanning, faxing, and copying functions. Furthermore, in the following description, front and rear refer to the front and rear sides of the image forming apparatus 1, and left and right refer to the left and right sides when viewing the image forming apparatus 1 from the front.

[0024] [Overall Structure]

[0025] Image forming apparatus 1 includes an image forming apparatus main body 2 and an image reading unit 3 disposed on the upper side of the main body 2. The image forming apparatus main body 2 has a printing unit 4 disposed in the middle of the main body 2 in the vertical direction and a paper feed cassette 5 disposed on the lower side of the printing unit 4. Paper is stored in the paper feed cassette 5. The printing unit 4 (image forming unit) prints (image forming) the paper supplied from the paper feed cassette 5 as a recording medium based on predetermined image data. The printing method in the printing unit 4 is, for example, an electrophotographic method. That is, the printing unit 4 has four photosensitive drum units corresponding to yellow, cyan, magenta and black. In each photosensitive drum unit, a laser corresponding to the image data is irradiated onto the surface of the photosensitive drum to form an electrostatic latent image, and the electrostatic latent image is developed using toner of each color. The developed toner image of each color is transferred once and superimposed on the surface of an intermediate transfer belt, and then transferred a second time to the paper supplied from the paper feed cassette 5.

[0026] Four photosensitive drum units are housed side-by-side in the image forming apparatus body 2 along a left-right direction and are configured to be insertable and removable from the front of the image forming apparatus body 2. An opening / closing cover 20 (an example of a cover component) is provided at the front of the storage space for the four photosensitive drum units. The opening / closing cover 20 is located mechanically inside the main cover 11 that covers the front of the image forming apparatus body 2. The opening / closing cover 20 is locked in the closed position by a locking mechanism 30, described later.

[0027] The image reading unit 3 optically reads the image of the original document placed on the contact glass on the upper surface of the image reading unit 3. The upper surface of the image reading unit 3 is covered by an openable and closable original document pressing cover 6 for pressing the original document. The original document pressing cover 6 is integrated with the automatic original document transport device 7. The automatic original document transport device 7 transports the original document placed on the original document feed tray along a predetermined transport path, and after passing the image reading position set on the contact glass, it is discharged into the original document discharge tray. An operation panel 8 is formed protruding from the front surface of the image reading unit 3. The operation panel 8 is provided with an operation section 9 including numeric keys and a start key, and a display section 10 composed of a liquid crystal display.

[0028] [Structure of the opening and closing cover]

[0029] Figure 3 This is a perspective view of the switch cover 20 from the surface side. Figure 4 This is a perspective view of the switch cover 20 viewed from the rear side. The switch cover 20 is constructed of a rectangular plate-shaped resin component that is longer in the left-right direction. At both ends of the base edge of the switch cover 20 in the left-right direction, U-shaped engaging fulcrum portions 21 that open downwards are formed. The left and right engaging fulcrum portions 21 engage with the left and right support shaft portions provided on the image forming apparatus body 2, respectively. Each support shaft portion extends horizontally in the left-right direction, and the switch cover 20 is configured such that the front side of the aforementioned storage space can be opened and closed by rotating around the left and right support shaft portions as fulcrums. In the following description, the side of the switch cover 20 where the left and right engaging fulcrum portions 21 are provided is defined as the base end side, and the side opposite to the base end side is defined as the front end side.

[0030] like Figure 3 As shown, a manual operating lever 35 (an example of a manual operating part) is provided in a recess 22, which is located at the center of the outer side of the opening / closing cover 20 in the left-right direction. The manual operating lever 35 passes through the opening / closing cover 20 and is rotatably and integrally connected to the shaft component 31 of the locking mechanism 30, which will be described later.

[0031] like Figure 4 As shown, a pair of end longitudinal ribs 24 and a plurality of intermediate longitudinal ribs 25 are formed on the edge of the front end side (the edge opposite to the base end side) of the inner side of the opening and closing cover 20.

[0032] A pair of longitudinal ribs 24 are provided at the left and right ends of the edge of the front end of the opening and closing cover 20.

[0033] Multiple intermediate longitudinal ribs 25 are arranged between a pair of end longitudinal ribs 24, spaced apart in the left-right direction. For example... Figure 5 As shown, the longitudinal ribs 24 at both ends and a plurality of intermediate longitudinal ribs 25 are disposed between the transverse ribs 27 extending along the edge of the front end side of the opening and closing cover 20 and the side wall 28 of the front end side of the opening and closing cover 20.

[0034] like Figure 5 and Figure 6 As shown, U-shaped bearing recesses 24a and 25a that open toward the inside of the device are formed at the two end longitudinal ribs 24 and the middle longitudinal rib 25, respectively.

[0035] like Figures 7 to 10 As shown, on the outer sides of a pair of longitudinal ribs 24 at both ends in the left and right directions, spring fitting recesses 26 are formed for the torsion coil spring 34 of the locking mechanism 30 described later to be fitted and mounted. The spring fitting recesses 26 are composed of U-shaped recesses that are formed coaxially with the bearing recesses 24a and 25a and open to the inside of the device.

[0036] [Structure of the locking mechanism]

[0037] Next, refer to Figures 7 to 10 The details of the locking mechanism 30 are explained below. All figures show the opening / closing cover 20 in the closed position. Unless otherwise specified, the following descriptions will assume the opening / closing cover 20 is in the closed position.

[0038] The locking mechanism 30 includes: a shaft member 31, which is mounted on the edge of the front end side of the opening and closing cover 20; left and right hook members 32, which are rotatably and integrally fixed on the shaft member 31; and left and right torsion coil springs 34, which exert force on the hook members 32 around the shaft member 31.

[0039] Viewed from the axial direction of the shaft member 31, each hook member 32 is inclined downwards and rearwards. Each hook member 32, viewed from the axial direction of the shaft member 31, has a shape that is sharp and acute-angled towards the front end. At the rear end of the upper end face of the hook member 32, an inclined surface 32a is formed, sloping downwards and rearwards. At the upper end of the front end face of the hook member 32, a V-shaped engaging recess 32b is formed, recessed towards the rear. Each hook member 32 is always positioned upwards and downwards around the shaft member 31 by a torsion coil spring 34. Figure 9 Apply force in the counterclockwise direction.

[0040] When the opening / closing cover 20 is moved from the open position to the closed position (from... Figure 9 When the left side of the image forming apparatus rotates to the right side, the inclined surface 32a of the hook component 32 engages with the engaged shaft portion 33 (see reference 33) located within the main body 2 of the image forming apparatus. Figure 9 ) Abutment. When the opening / closing cover 20 is rotated further toward the closing side, the inclined surface 32a is pushed downward by the engaged shaft portion 33, and the hook component 32 and the shaft component 31 move together toward Figure 9 It rotates clockwise. Furthermore, when the opening / closing cover 20 reaches the closed position ( Figure 9 When the hook component 32 is in its original position, its upper end face passes through the engaged shaft portion 33 and ends. As a result, the hook component 32 returns to its original position under the force of the torsion coil spring 34. Consequently, the engaging recess 32b (engaging hook portion) of the hook component 32 engages with the engaged shaft portion 33 (engaged portion), locking the opening / closing cover 20 in a position that cannot be opened. To unlock, simply move the manual operating lever 35 (see reference 32b) provided on the opening / closing cover 20. Figure 3 Simply lift it towards the front. This will cause the shaft component 31, connected to the manual operating lever 35, to... Figure 9 Rotate clockwise to release the engagement between the hook part 32 and the engaged shaft part 33.

[0041] However, in typical locking mechanisms, the increased number of parts and consequently higher costs are due to the bearing components supporting both ends of the shaft component. To avoid this problem, this embodiment focuses on optimizing the mounting structure of the shaft component 31 and the torsion coil spring 34.

[0042] [Details of the mounting structure for shaft component 31 and torsion coil spring 34]

[0043] The shaft component 31 is fitted into the bearing recesses 24a of the end longitudinal ribs 24 and the bearing recesses 25a of the middle longitudinal rib 25. The two ends of the shaft component 31 protrude outward in the left and right directions beyond the end longitudinal ribs 24 and are internally (inserted) supported by left and right torsion coil springs 34. The left and right torsion coil springs 34 function as bearing components supporting the two ends of the shaft component 31.

[0044] The torsion coil spring 34 has a spring body portion 34a, a first straight portion 34b, a second straight portion 34c, a fixed curved portion 34d, a hook component engaging portion 34e, and a guide groove engaging portion 34f.

[0045] The spring body 34a is a spiral portion that generates restoring force in the torsional direction, and is generally cylindrical in appearance. The spring body 34a is arranged such that its outer peripheral surface is in close contact with the inner peripheral surface of the spring fitting recess 26.

[0046] The first straight portion 34b and the second straight portion 34c extend from both ends of the spring body portion 34a along the tangential direction of the spring body portion 34a. Viewed from the axial direction of the spring body portion 34a, the first straight portion 34b extends rearward from the lower end of the spring body portion 34a. Viewed from the axial direction of the spring body portion 34a, the second straight portion 34c extends rearward from the upper end of the spring body portion 34a.

[0047] The fixed curved portion 34d is connected to the front end of the first straight portion 34b and bends downward (in an example of a direction orthogonal to the axial direction of the shaft component 31). For example... Figure 9 As shown, the fixing bend 34d abuts against the rear wall surface of the engaging recess 27a (an example of the fixed portion) formed on the transverse rib 27. As a result, the spring body portion 34a of the torsion coil spring 34 is given a forward reaction force via the fixing bend 34d.

[0048] The hook component engaging portion 34e is connected to the front end of the second straight portion 34c and is bent to surround the hook component 32. The hook component engaging portion 34e abuts against the hook component 32 from below. As a result, the hook component 32 is always subjected to an upward force by the torsion coil spring 34.

[0049] The guide groove engaging portion 34f extends from the end of the hook component engaging portion 34e along the axial direction (left-right direction) of the shaft component 31. The front end of the guide groove engaging portion 34f passes through the guide groove 24b formed in the longitudinal ribs 24 at both ends (see reference). Figure 7 The guide groove 24b and the hook component 32 swing together to guide the guide groove engaging part 34f to move in an arc shape.

[0050] [Effects]

[0051] As explained above, in the above embodiment, when the torsion coil spring 34 is engaged with the hook member 32 in the engagement recess 26, it applies force to the hook member 32 around the axis of the shaft member 31 toward the locking side, and rotatably supports both ends of the shaft member 31 on the inner side of the coil, thus functioning as a bearing member.

[0052] According to this structure, the torsion coil spring 34 used to apply force to the locking side of the hook component 32 also serves as a bearing component for supporting the shaft component 31, thus reducing the number of components and lowering product costs.

[0053] Furthermore, in the above embodiment, the torsion coil spring 34 includes: a spiral spring body portion 34a; a first straight portion 34b and a second straight portion 34c extending tangentially from both ends of the spring body portion 34a; and a fixing bent portion 34d connected to the first straight portion 34b, bent in a direction orthogonal to the axial direction of the spring body portion 34a, and engaged and fixed with the engaging recess 27a. The torsion coil spring 34 is configured such that the reaction force received from the wall surface of the engaging recess 27a by the fixing bent portion 34d presses the spring body portion 34a into the spring engaging recess 26.

[0054] According to this structure, the torsion coil spring 34 can be securely fixed to the spring fitting recess 26. As a result, the torsion coil spring 34 can be prevented from falling off or wobbling due to the rotation of the shaft component 31.

[0055] In addition, in the above embodiment, the opening and closing cover 20 has an arc-shaped guide groove 24b, which guides the other end (guide groove engaging part 34f) of the torsion coil spring 34 that moves in conjunction with the swinging action of the hook member 32.

[0056] According to this structure, the other end of the torsion coil spring 34 is guided (supported) by the guide groove 24b, thus more reliably preventing the torsion coil spring 34 from falling off and loosening.

[0057] Other Implementation Methods

[0058] In the above embodiment, the locking mechanism 30 is applied to the image forming apparatus 1, but the present invention is not limited to this embodiment. The locking mechanism 30 can be applied to any apparatus, as long as it is an apparatus with an opening and closing cover 20.

[0059] Industrial availability

[0060] This invention is useful for locking mechanisms and image forming apparatuses equipped with locking mechanisms, particularly in applications such as printers, fax machines, copiers, or multifunction printers (MFPs).

Claims

1. A locking mechanism, characterized in that, have: The cover component can be opened and closed by rotating about one end edge as a fulcrum; A shaft component extends along an end edge opposite to one end edge of the cover component, and both ends are rotatably supported by the cover component; The hook component is rotatably and integrally connected to the shaft component, and has an engaging hook portion formed at its front end; The engaging portion is used to lock the cover component by engaging with the engaging hook portion of the hook component when the cover component is moved to the closed position; A torsion coil spring is used to apply force to the hook component toward the side where the engaging hook and the engaged part are engaged, i.e., the locking side. as well as The manual operating unit is used to manually rotate the shaft component when the cover component is in the closed position, thereby releasing the engagement between the engaging hook and the engaged part. The cover component includes: A fitting recess, opening to a side orthogonal to the axis of the shaft component, receives the torsion coil spring from said side and fits into the outer peripheral surface of the torsion coil spring; and The fixing part is used to fix one end of the torsion coil spring. When the torsion coil spring is engaged with the hook component, it applies force to the hook component about the axis of the shaft component toward the locking side, and serves as a bearing component supporting the two ends of the shaft component, rotatably supporting the two ends of the shaft component on the inner side of the coil of the torsion coil spring.

2. The locking mechanism according to claim 1, characterized in that, The cover component has an engaging recess that serves as the fixed portion. The torsion coil spring has: a helical spring body; a first straight portion and a second straight portion extending tangentially from both ends of the spring body; and a fixing bending portion connected to the first straight portion, bending in a direction orthogonal to the axial direction of the spring body, and engaging and fixing with the engaging recess, wherein the fixing bending portion is configured to press the spring body into the engaging recess by a reaction force received from the wall surface of the engaging recess.

3. The locking mechanism according to claim 2, characterized in that, The cover component also has an arc-shaped groove that guides the other end of the torsion coil spring, which moves in conjunction with the swinging motion of the hook component.

4. The locking mechanism according to claim 2, characterized in that, The torsion coil spring also includes a hook engagement portion, which is connected to the front end of the second straight portion and is bent to surround the hook component, and the hook engagement portion abuts against the hook component.

5. An image forming apparatus, characterized in that, have: The locking mechanism according to claim 1; The main body is used for providing the engaging portion; and An image forming unit is used to form an image on a recording medium.

Images