JP7180725B2 - developer cartridge - Google Patents

Description

The present invention relates to a developer cartridge containing developer.

2. Description of the Related Art Conventionally, a developer cartridge is known that includes a detection projection that engages with an actuator provided in a main body housing of an image forming apparatus, and a detection gear having the detection projection (see, for example, Japanese Unexamined Patent Application Publication No. 2002-200012). ). Specifically, in this technology, when the developer cartridge is installed, the detection projection pushes the actuator. After that, when a driving force is input to the development cartridge, the detection gear rotates, causing the detection projection to further push the actuator, and then the actuator It is structured to evacuate from In addition, in this technology, the number of detection protrusions is changed according to the specifications, so that the control device can determine the number of times the actuator has been pressed by the detection protrusions, and the control device can determine the specifications of the developer cartridge. It is possible to

Japanese Patent No. 4348632

By the way, the inventor of the present application has devised a detection gear having a novel configuration that has never existed before.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a developer cartridge having a detection gear with a novel configuration.

In order to solve the above-described problems, a developer cartridge according to the present invention includes a housing capable of accommodating a developer, a first gear rotatable about a first axis extending in an axial direction, and comprising a small-diameter gear portion and a small-diameter a first gear having a large-diameter gear portion having a diameter larger than that of the gear portion; and a second gear rotatable about a second axis extending in the axial direction, the second gear extending in the axial direction and centering on the second axis. a second columnar portion extending in the axial direction around the second axis, the second columnar portion having a diameter smaller than that of the first columnar portion; A first engaging portion along a portion of the peripheral surface, the first engaging portion being engageable with the small-diameter gear portion, and a second engaging portion along a portion of the peripheral surface of the second columnar portion. a second engaging portion arranged closer to the housing than the first engaging portion in the axial direction and capable of being engaged with the large-diameter gear portion; a second gear having an engaging portion and a projection rotatable with the second engaging portion.
The second engaging portion is engageable with the large-diameter gear portion after the first engaging portion and the small-diameter gear portion are engaged.

Further, the developer cartridge according to the present invention includes a housing capable of accommodating developer, a first gear rotatable about a first axis extending in an axial direction, and a small-diameter gear portion having a diameter larger than that of the small-diameter gear portion. and a second gear rotatable about a second axis extending in the axial direction, the first engaging portion along a part of the peripheral surface of the second gear a first engaging portion engageable with the small-diameter gear portion; a second engaging portion along the portion, which is arranged at a position different from the first engaging portion in the rotation direction of the second gear, and after the first engaging portion and the small diameter gear portion are engaged a second gear having a second engaging portion engageable with the large-diameter gear portion, and a projecting portion projecting in the axial direction and rotatable together with the first engaging portion and the second engaging portion; , provided.
A rotational trajectory defined by rotation of the second engaging portion is smaller than a rotational trajectory defined by rotation of the first engaging portion.

According to each configuration described above, the detection gear rotates while the small-diameter gear portion and the first engaging portion are engaged and while the large-diameter gear portion and the second engaging portion are engaged. Compared to a configuration without two engaging portions, the amount of rotation of the detection gear can be increased, and the amount of movement of the protruding portion can be increased, so that new product detection and specification detection can be performed satisfactorily.

According to the present invention, it is possible to provide a developer cartridge having a detection gear with a novel configuration.

1 is a perspective view showing a developing cartridge and actuators of an image forming apparatus according to an embodiment of the present invention; FIG. FIG. 3 is an exploded perspective view showing parts of an actuator and a developing cartridge in an exploded manner; It is a side view (a) which shows a developing cartridge, and the figure (b) which shows simply the gear mechanism provided in the developing cartridge. It is the front view (a), side view (b), and rear view (c) which show a standard type detection gear. It is the front view (a), side view (b), and rear view (c) which show a large-capacity type detection gear. It is the front view (a) and side view (b) which show a transmission gear. It is sectional drawing (a) which shows the relationship between a standard type spring engaging part and a torsion spring, and sectional drawing (b) which shows the relationship between a large capacity type spring engaging part and a torsion spring. 10A and 10B are cross-sectional views showing angles at an assembly position of a standard type detection gear; FIG. 10A and 10B are cross-sectional views showing angles of a standard type detection gear at an inspection position; FIG. 10A and 10B are cross-sectional views showing the angle of the standard type detection gear at the initial position; FIG. It is sectional drawing (a) and (b) which shows the angle in the assembly|attachment position of a large-capacity type detection gear. It is sectional drawing (a) and (b) which shows the angle in the test|inspection position of a large-capacity type detection gear. It is sectional drawing (a) and (b) which shows the angle in the initial position of a large-capacity type detection gear. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part in the standard type when the detection gear is in the initial position. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the first gear tooth portion of the detection gear meshes with the small-diameter gear portion of the transmission gear in the standard type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the actuator is detached from the outer peripheral surface of the detection protrusion in the standard type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the first gear tooth portion of the detection gear is disengaged from the small-diameter gear portion of the transmission gear in the standard type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the second gear tooth portion of the detection gear is in mesh with the large-diameter gear portion of the transmission gear in the standard type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part in the standard type when the detection gear is at the final position. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part in the large-capacity type when the detection gear is in the initial position. 8A to 8C are cross-sectional views (a) to (c) showing the state of each part when the first gear tooth portion of the detection gear meshes with the small-diameter gear portion of the transmission gear in the large-capacity type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the actuator is disengaged from the outer peripheral surface of the detection protrusion in the large-capacity type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the first gear tooth portion of the detection gear is disengaged from the small-diameter gear portion of the transmission gear in the large-capacity type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part when the second gear tooth portion of the detection gear is in mesh with the large-diameter gear portion of the transmission gear in the large-capacity type. 10A to 10C are cross-sectional views (a) to (c) showing the state of each part in the large-capacity type when the detection gear is at the final position. It is the perspective view (a) which shows a standard type detection gear, and the perspective view (b) which shows a large-capacity type detection gear. It is a figure which shows the modification of a gear tooth.

Next, a detailed structure of the developer cartridge 8 as an example of the developer cartridge according to the embodiment of the present invention will be described. In the following description, directions are described in the directions shown in FIG. That is, in FIG. 3, the right side is called the "front side", the left side is called the "rear side", the back side in the direction perpendicular to the paper surface is called the "right side", and the front side in the direction perpendicular to the paper surface is called the "left side". . As for the vertical direction, the vertical direction in FIG. 3 will be referred to as the "vertical direction" as it is.

As shown in FIGS. 1 and 2, a developing roller 81 extending in the axial direction, a cartridge body 100 as an example of a housing, a first gear cover 200, a second gear cover 600, and exposed to the outside from the first gear cover 200. A detection protrusion 301 is provided as an example of a protrusion. The detection protrusion 301 is provided on a detection gear 300 that rotates around a second axis CL2 extending in the axial direction. Inside the cartridge main body 100, there are provided a toner containing portion 84 containing toner as an example of a developer, an agitator 85 for agitating the toner in the toner containing portion 84, and a developer roller 81 for supplying the toner to the developing roller 81. A supply roller 83 and the like are provided.

Specifically, as shown in FIG. 3(a), the detection protrusion 301 has an arc-shaped outer peripheral wall 301A centered on the second axis CL2 and a first end A1, which is one end of the outer peripheral wall 301A, in a radial direction. It has a first extension wall 301B extending inward and a second extension wall 301C extending radially inward from a second end A2, which is the other end of the outer peripheral wall 301A. The first end A1 is one end in the rotation direction of the outer peripheral wall 301A, and the second end A2 is the other end opposite to the first end A1 in the rotation direction of the outer peripheral wall 301A. 301 A of outer peripheral walls, the 1st extension wall 301B, and 301 C of 2nd extension walls are arrange|positioned in the position shifted|deviated from 2nd axis line CL2. The first extension wall 301B extends from the first end A1 of the outer peripheral wall 301A toward the rotating shaft portion 310, which will be described later. The first extension wall 301B is connected to the rotating shaft portion 310 of the detection gear 300. As shown in FIG. The second extension wall 301C extends from the other end of the outer peripheral wall 301A toward the rotating shaft portion 310. As shown in FIG. The second extension wall 301C is an example of an extension portion, and extends so as to curve away from the outer peripheral wall 301A of the detection gear 300 as it goes from the second end A2 of the outer peripheral wall 301A toward the rotation shaft portion 310. ing. Specifically, the second extension wall 301C extends radially inward and upstream in the rotational direction from the second end A2, and is curved to be convex downstream in the rotational direction.
The second extension wall 301C is connected to a rotating shaft portion 310 of the detection gear 300, which will be described later.
The cartridge body 100 has a first outer surface 100A (see FIG. 2) on which a gear train such as the detection gear 300 is arranged, and a second outer surface opposite to the first outer surface 100A.

As shown in FIGS. 2 and 3B, an input gear 110, a developing roller drive gear 120, a supply roller drive gear 130, and an idle gear 140 are provided on the first outer surface 100A on the left-right direction outer side of the cartridge body 100. , a detection gear 300 as an example of a second gear, and a transmission gear 400 as an example of a first gear are rotatably provided. In addition, in FIG.3(b), each gear is simplified and illustrated.

The input gear 110 is provided coaxially and integrally with an input coupling 101 (see FIG. 3A) to which driving force is input from a motor (not shown) provided in the main body of the image forming apparatus. can be rotated to The developing roller driving gear 120 is supported by the rotating shaft 81 A of the developing roller 81 , is rotatable together with the developing roller 81 , and meshes with the input gear 110 . The input coupling 101 has a cylindrical portion 102 extending in the axial direction and a pair of protrusions 103 protruding radially inward from the inner peripheral surface of the cylindrical portion 102 . The protrusion 103 can be engaged with a body-side coupling (not shown) provided on the body of the image forming apparatus.

The supply roller driving gear 130 is supported by the rotating shaft 83A of the supply roller 83, is rotatable together with the supply roller 83, and meshes with the input gear 110. As shown in FIG. Idle gear 140 meshes with input gear 110 and transmission gear 400 .

Transmission gear 400 is a gear that receives driving force from idle gear 140 to rotate, and is configured to intermittently transmit driving force to detection gear 300 . The detection gear 300 is a gear that rotates only while receiving the driving force from the transmission gear 400 . Upon receiving a force, the detection protrusion 301 is configured to move toward the final position and stop after the detection protrusion 301 is positioned at the final position.

Specifically, as shown in FIGS. 4(a) to 4(c) and FIG. 26(a), the standard type detection gear 300 includes the detection projection 301 described above and a rotation shaft as an example of the second columnar portion. a portion 310, a flange portion 320 as an example of a disk portion, a first toothless gear portion 330, a second rib 340 functioning as a trigger, a second toothless gear portion 350, and a first regulated portion 360. , a spring engaging portion 370 and a cylindrical portion 380 are integrally provided. The rotating shaft portion 310 extends in the axial direction, is formed in a cylindrical shape about the second axis CL2, and is rotatable with respect to the cartridge main body 100. As shown in FIG. The diameter of the rotating shaft portion 310 is shorter than the diameter of the cylindrical portion 380 . The rotating shaft portion 310 has a diameter smaller than that of a first toothless portion 331 to be described later. As shown in FIG. 2, the rotating shaft portion 310 is positioned on the first outer surface 100A of the cartridge body 100 and is rotatably supported by a boss 155 extending in the axial direction. As shown in FIG. 26 , the rotating shaft portion 310 has a rib 311 that protrudes from the peripheral surface and comes into contact with the axial end face of the second gear tooth portion 352 to be described later. Returning to FIG. 2 , the boss 155 is provided on the cap 150 which is a separate member from the cartridge body 100 and protrudes from the first outer surface 100A of the cartridge body 100 . Here, the cap 150 is a lid for closing the filling port 84A for filling toner into the toner containing portion 84 . As shown in FIG. 4B, the flange portion 320, the first tooth-missing gear portion 330, and the second tooth-missing gear portion 350 extend from the upper side in the figure (outer side in the axial direction) to the lower side in the figure (inner side in the axial direction: the cartridge main body 100). side) are arranged side by side in this order. That is, the distance from the first outer surface 100A to the first partially toothed gear portion 330 is longer than the distance from the first outer surface 100A to the second partially toothed gear portion 350 in the axial direction. Further, the distance from the first outer surface 100A to the first toothless gear portion 330 is shorter than the distance from the first outer surface 100A to the flange portion 320 in the axial direction.

The flange portion 320 extends radially outward from a substantially central portion in the axial direction of the rotating shaft portion 310 and is rotatable about the second axis CL2. The flange portion 320 is arranged at a position farther from the cartridge body 100 than the first toothless gear portion 330 . The detection protrusion 301 is arranged on the surface of the flange portion 320 opposite to the surface facing the cartridge body 100 . The detection projection 301 is formed so as to protrude from the surface of the flange portion 320 opposite to the surface facing the cartridge main body 100 . Specifically, the detection projection 301 protrudes along the axial direction away from the cartridge body 100 . The detection projection 301 is rotatable together with a first gear tooth portion 332 and a second gear tooth portion 352, which will be described later.
The cylindrical portion 380 is an example of a first columnar portion and is formed in a cylindrical shape extending along the axial direction and centered on the second axis CL2. The cylindrical portion 380 extends from the surface of the flange portion 320 facing the cartridge body 100 toward the cartridge body 100 . The rotating shaft portion 310 is arranged inside the cylindrical portion 380 .

The first tooth-missing gear portion 330 is arranged at the same position in the axial direction as the first tooth-missing portion 331 having a substantially cylindrical peripheral surface, and the first tooth-missing portion 331 and the peripheral surface of the cylindrical portion 380. and a plurality of first gear teeth 332 projecting radially outward from. The first toothless portion 331 is formed by the peripheral surface of the cylindrical portion 380 . A plurality of first gear teeth 332 extend along a portion of the circumferential surface of cylindrical portion 380 . The first gear tooth portion 332 is an example of a first engagement portion, and is engageable with a small-diameter gear portion 450 of the transmission gear 400, which will be described later. As shown in FIG. 4C, the first gear tooth portion 332 has a third end portion 332A, which is the end portion of the gear teeth located on the downstream side in the rotational direction, and an end portion on the upstream side in the rotational direction. and a fourth end 332B which is the end of the gear tooth located. The third end 332A is one end of the first gear tooth 332 in the rotational direction, and the fourth end 332B is the other end opposite to the third end 332A of the first gear tooth 332 in the rotational direction. Department. A fourth end portion 332</b>B on the upstream side in the rotation direction of the first gear tooth portion 332 is arranged downstream of the first extension wall 301</b>B of the detection projection 301 . The number of first gear teeth 332 varies according to specifications. In the standard type, the angle θ4 formed by a line segment L4 connecting the fourth end portion 332B of the first gear tooth portion 332 and the second axis CL2 and a line segment L5 connecting the third end portion 332A and the second axis CL2 is , 73° or more and 78° or less. In this embodiment, θ4 is 74°.

A first projection 381 and a second projection 382 projecting radially outward from the tip of the first gear tooth portion 332 are provided between the first toothless gear portion 330 and the flange portion 320 . The first projection 381 is arranged substantially opposite to the first regulated portion 360, which will be described later, across the second axis CL2, and the second projection 382 is arranged downstream of the first projection 381 in the rotational direction. ing. Note that only the first protrusion 381 is provided for the large capacity type (see FIG. 5(c)).

As shown in FIGS. 4(b) and 4(c), the second partially toothed gear portion 350 is arranged downwardly in the drawing from the first partially toothed gear portion 330 by a predetermined distance. The second tooth-missing gear portion 350 is arranged at the same position in the axial direction as the second tooth-missing portion 351 having a substantially cylindrical peripheral surface and the second tooth-missing portion 351, and and a plurality of second gear teeth 352 projecting radially outwardly from the face. Note that the rotating shaft portion 310 corresponds to the second columnar portion. The plurality of second gear tooth portions 352 are an example of a second engaging portion and extend along part of the peripheral surface of the rotation shaft portion 310 .
The second toothless portion 351 is formed by the peripheral surface of the rotating shaft portion 310 . The diameter of the second gear tooth portion 352 is smaller than the diameter of the first gear tooth portion 332 . In this embodiment, the distance from the second axis CL2 to the tip of the first gear tooth 332 is 11.5 mm, and the distance from the second axis CL2 to the tip of the second gear tooth 352 is 6.7 mm. is.

The rotation locus defined by the rotation of the tip of the second gear tooth portion 352 is smaller than the rotation locus defined by the rotation of the tip of the first gear tooth portion 332 . The second gear tooth portion 352 is arranged closer to the cartridge body 100 than the first gear tooth portion 332 in the axial direction (see FIG. 2), and can be engaged with the large diameter gear portion 440 of the transmission gear 400 described later. ing. The second gear tooth portion 352 is arranged upstream of the first gear tooth portion 332 in the rotational direction, and engages with the large diameter gear portion 440 after the first gear tooth portion 332 and the small diameter gear portion 450 are engaged. . The second gear tooth portion 352 includes a fifth end portion 352A, which is the end portion of the gear teeth located at the end portion on the downstream side in the rotation direction, and a fifth end portion 352A, which is the end portion of the gear teeth located at the end portion on the upstream side in the rotation direction. 6 ends 352B. The fifth end 352A is one end of the second gear tooth 352 in the rotational direction, and the sixth end 352B is the other end opposite to the fifth end 352A of the second gear tooth 352 in the rotational direction. Department. The fifth end 352A is positioned closer to the fourth end 332B than the sixth end 352B in the rotational direction. The structure of the second gear tooth portion 352 and the positional relationship between the second gear tooth portion 352 and the first gear tooth portion 332 are the same between the standard type and the large capacity type. Specifically, as shown in FIG. 5C, a line segment L4 connecting a fourth end 332B on the upstream side in the rotation direction of the first gear tooth 332 and the second axis CL2, and a line segment L4 connecting the second gear tooth An angle θ3 formed between a fifth end portion 352A on the downstream side in the rotation direction of 352 and a line segment L3 connecting the second axis CL2 is set within a range of 35° or more and 41° or less. An angle θ6 formed by a line segment L3 connecting the fifth end portion 352A of the second gear tooth portion 352 and the second axis CL2 and a line segment L6 connecting the sixth end portion 352B and the second axis CL2 is 28. It is set in the range of 32° or less. In this embodiment, θ3 is 38° and θ6 is 29°.

As shown in FIG. 4B, the spring engaging portion 370 is a portion that contacts a torsion spring 500 (see FIG. 7A), which will be described later. It is arranged between the two-part gear part 350 . Specifically, the spring engaging portion 370 is arranged adjacent to the upper side of the second toothless gear portion 350 in the figure. As shown in FIG. 4(c), the spring engaging portion 370 protrudes radially outward from the rotating shaft portion 310, and its length in the rotating direction is equal to that of the second gear tooth portion 352 described above or the second gear tooth portion described later. It is larger than rib 340 .

More specifically, the spring engaging portion 370 includes a third rib 371 and a fourth rib 372 projecting from the outer peripheral surface of the rotating shaft portion 310 in a direction intersecting the axial direction, and the diameters of the third rib 371 and the fourth rib 372. It has an arc-shaped connecting rib 373 that connects the ends on the outer side in the direction. The third rib 371 is arranged on the downstream side in the rotational direction with respect to the fourth rib 372 . In other words, the third rib 371 is arranged closer to the second gear tooth portion 352 than the fourth rib 372 is.

The second rib 340 is arranged at the same position as the spring engaging portion 370 in the axial direction, and is provided on the opposite side of the second gear tooth portion 352 across the second axis CL2. The second rib 340 is arranged on the outer peripheral surface of the rotating shaft portion 310 . The second rib 340 extends radially outward (in a direction that intersects the second axis CL2) from the outer peripheral surface of the rotating shaft portion 310 and is formed in a plate shape (rib shape) that intersects with the rotational direction. A radially outer tip portion of the second rib 340 is arranged radially inward of the peripheral surface of the first toothless portion 331 and radially outward of the second gear tooth portion 352 . Specifically, the radially outer tip portion of the second rib 340 is arranged at substantially the same position as the outer peripheral surface of the spring engaging portion 370 in the radial direction.

As shown in FIG. 4B , the first regulated portion 360 protrudes from the peripheral surface of the cylindrical portion 380 . The first regulated portion 360 extends from the cylindrical portion 380 to the end portion of the spring engaging portion 370 near the flange portion 320 in the axial direction. As shown in FIG. 4C, the first regulated portion 360 is arranged upstream of the second gear tooth portion 352 and downstream of the second rib 340 in the rotational direction.

The first regulated portion 360 is arranged at substantially the same position as the spring engaging portion 370 in the rotational direction, protrudes radially outward from a position near the outer peripheral surface of the spring engaging portion 370, and has a first toothless portion at its tip. It is arranged radially outside the peripheral surface of 331 . The surface on the upstream side in the rotational direction of the first regulated portion 360 is a surface that is substantially perpendicular to the rotational direction, and the surface on the downstream side is an inclined surface that is inclined toward the downstream side and radially inward.

As shown in FIGS. 5(a) to (c) and FIG. 26(b), the large-capacity type detection gear 300 differs from the standard type in the following points, but the structure itself is substantially the same as the standard type. Therefore, the same reference numerals are given to each configuration, and the description thereof will be omitted as appropriate.

In the large-capacity type, the fourth end portion 332B on the upstream side in the rotation direction of the first gear tooth portion 332 is arranged on the upstream side of the first extension wall 301B of the detection protrusion 301 . An angle θ5 formed by a line segment L4 connecting the fourth end portion 332B of the first gear tooth portion 332 and the second axis CL2 and a line segment L5 connecting the third end portion 332A and the second axis CL2 is 146. ° or more and 150° or less. In this embodiment, θ5 is 147°.

The large-capacity type spring engaging portion 370 has a third rib 371 and a fourth rib 372 . In the direction of rotation, the fourth rib 372 is provided on the side opposite to the third rib 371 with the second rib 340 interposed therebetween. Also, the large-capacity type third rib 371 is arranged at substantially the same position as the upstream side portion of the second gear tooth portion 352 in the rotational direction. Also, the fourth rib 372 is arranged on the opposite side of the third rib 371 across the second axis CL2.

As shown in FIG. 3, the transmission gear 400 is a gear that is rotatable about a first axis CL1 extending in the axial direction, and is arranged adjacently upstream of the detection gear 300 in the driving force transmission direction. It is supported by a rotating shaft 85A (see FIG. 2) of 85 and is rotatable together with the agitator 85. As shown in FIG. As shown in FIGS. 6A and 6B, the transmission gear 400 includes a rotating shaft portion 430, a large-diameter gear portion 440, a small-diameter gear portion 450, and a first rib 460 functioning as a trigger. have as one. The rotation shaft portion 430 is formed in a substantially cylindrical shape centered on the first axis CL1, which is the rotation axis of the transmission gear 400. As shown in FIG. In the axial direction, the distance from first outer surface 100A to large diameter gear portion 440 is shorter than the distance from first outer surface 100A to small diameter gear portion 450 .

The large-diameter gear portion 440 is a gear having a larger diameter than the small-diameter gear portion 450, and is rotatable together with the small-diameter gear portion 450 about the first axis CL1. The large-diameter gear portion 440 meshes with the idle gear 140 (see FIG. 3B), and receives driving force from the idle gear 140 . Further, the large-diameter gear portion 440 faces the second toothless portion 351 (see FIG. 4C) of the detection gear 300 in the initial state, and is appropriately rotated after the driving force is input to the developing cartridge 8 . It meshes with the second gear tooth portion 352 of the detection gear 300 at the timing.

In the initial state, the small-diameter gear portion 450 faces the first toothless portion 331 (see FIG. 4C) of the detection gear 300, and is detected at an appropriate timing after the driving force is input to the developing cartridge 8. It meshes with the first gear tooth portion 332 of the gear 300 .

The first rib 460 is formed in a rib shape (plate shape) extending radially outward (in a direction intersecting the first axis CL1) from the base end portion of the small-diameter gear portion 450. It is inclined upstream in the rotational direction and radially outward. As shown in FIG. 15( b ), the first rib 460 engages the second rib 340 of the detection gear 300 to rotate the detection gear 300 so that the first gear tooth portion 332 moves to the small diameter gear portion 450 . It is a part for meshing, and is arranged so that the rotation locus of the first rib 460 overlaps with the rotation locus of the second rib 340 . In the initial state shown in FIG. 14B, the first rib 460 is arranged at a position separated from the second rib 340 downstream in the rotation direction of the transmission gear 400 .

As shown in FIG. 7( a ), the cartridge body 100 is provided with a torsion spring 500 that engages with the spring engaging portion 370 of the detection gear 300 . 7 and the like, the gear teeth of the large-diameter gear portion 440 are omitted as appropriate.

The torsion spring 500 is a torsion coil spring, and includes a coil portion 501 , a first arm 510 extending upward from the detection gear 300 from the coil portion 501 , and a rotation shaft portion 310 extending from the coil portion 501 toward the rotation shaft portion 310 of the detection gear 300 . and a second arm 520 . The coil portion 501 has a central axis along the rotation axis. The coil portion 501 is arranged behind the cap 150 . The tip of the first arm 510 contacts a spring support portion 151 of the cap 150 to be described later from above. The second arm 520 extends from the coil portion 501 toward the rotating shaft portion 310 and then bends so that the tip thereof extends away from the first arm 510 and contacts the spring engaging portion 370 from behind. The first arm 510 and the second arm 520 extend to cross each other.

The torsion spring 500 urges the detection gear 300 clockwise in the state where the detection gear 300 is in the initial position shown in FIG. 7(a). That is, at the initial position, the torsion spring 500 biases the third rib 371 of the detection gear 300 in the direction opposite to the direction of rotation of the detection gear 300 to which the drive force is transmitted.

The cap 150 includes a spring supporting portion 151 that supports one end of the torsion spring 500, a restricting portion 152 that restricts the rotation of the detection gear 300 clockwise in the drawing at the initial position, and a predetermined position of the detection gear 300 during product inspection. It has a holding portion 153 held at an inspection position and a plate-like base 154 . As shown in FIG. 10(a), the regulating portion 152 is in contact with the first regulated portion 360 of the detection gear 300 at the initial position. Specifically, the torsion spring 500 urges the third rib 371 of the spring engaging portion 370 clockwise (opposite to the rotational direction) in the figure, so that the first regulated portion 360 is directed toward the regulating portion 152 . Its movement is regulated by the regulating portion 152 . Thereby, the detection gear 300 is satisfactorily positioned at the initial position.

The base 154 is located on the first outer surface 100A of the cartridge body 100. As shown in FIG. The spring support portion 151 is a rib protruding from the base 154 in the axial direction. The spring support portion 151 extends in the front-rear direction along the shape of the first arm 510 of the torsion spring 500 . A surface of the spring support portion 151 opposite to the rotating shaft portion 130 is in contact with the first arm 510 of the torsion spring 150 . The first restricting portion 152 protrudes from the base 154 so as to extend in the rotation axis direction. The first restricting portion 152 extends vertically. The holding portion 153 is a rib that protrudes from the base 154 in the rotation axis direction and extends in the front-rear direction. One end of the holding portion 153 is connected to the end of the first restricting portion 152 near the detection gear 300 . The holding portion 153 is arranged so as to face the peripheral surface of the detection gear 300 , and the central portion in the front-rear direction is bent away from the detection gear 300 . The first restricting portion 152 and the holding portion 153 are arranged on the opposite side of the rotating shaft portion 310 from the spring supporting portion 151 . The cap 150 also has a boss 155 protruding from the base 154 in the axial direction. Boss 155 rotatably supports rotation shaft portion 310 of detection gear 300 . Boss 155 is positioned inside rotating shaft portion 310 of detection gear 300 .

As shown in FIG. 14(a), the first gear cover 200 has an arcuate wall 220 that is arranged radially outwardly of the detection projection 301 and extends arcuately about the second axis CL2. In the final position shown in FIG. 19(a), the detection projection 301 has its second extension wall 301C located downstream of the upstream end of the circular arc wall 220 in the rotational direction. The large-capacity type also has a similar structure (see FIG. 25(a)).

Next, the position of the detection gear 300 at the time of assembly, the position at the time of product inspection, and the position in the new state after the product is completed will be described.
As shown in FIG. 8( a ), when the detection gear 300 is assembled to the cartridge body 100 , the angle of the detection gear 300 is adjusted to the mounting position where the first regulated portion 360 contacts the base end portion of the holding portion 153 . adjust. At this time, the restricting portion 152 and the holding portion 153 hold the posture of the detection gear 300 in a state of bending downward in the drawing. At this time, since the torsion spring 500 contacts the rotation shaft portion 310, the biasing force of the torsion spring 500 is directed toward the rotation axis of the detection gear 300 and does not work in the direction of rotating the detection gear 300. Gear 300 is well retained in the mounted position. At the mounting position, movement restricting portion 210 is positioned inside groove portion 302 (see FIG. 26 ) formed in the peripheral surface of detection gear 300 .

After that, the first gear cover 200 (see FIG. 3A) is attached to the cartridge body 100 so as to cover the transmission gear 400 and the like. At this time, since the detection gear 300 is positioned at the mounting position described above, the ribs and projections extending in the left-right direction from the left-right outer wall of the first gear cover 200 do not come into contact with the detection gear 300, and the first gear cover 200 can be easily moved. can be attached to

After attaching the first gear cover 200, the operator rotates the detection gear 300 clockwise as shown in FIG. 9(a). Then, as shown in FIG. 9B, the detection gear 300 is stopped at the inspection position by the first protrusion 381 engaging with the movement restricting portion 210 formed on the first gear cover 200 in the rotational direction. At the inspection position, the first regulated portion 360 is held by the holding portion 153 by contacting the tip portion of the holding portion 153 .

Since the detection gear 300 is held at the inspection position in this way, the second rib 340 is removed from the rotational trajectory of the first rib 460. The first rib 460 does not engage with the second rib 340, and as a result, it is possible to prevent the detection gear 300 from rotating erroneously.

After the product inspection, as shown in FIG. 10A, the operator slightly rotates the detection gear 300 counterclockwise in the drawing to move the first regulated portion 360 to the right side of the regulating portion 152 in the drawing. , the angle of the detection gear 300 is adjusted to the initial position where the first regulated portion 360 contacts the right side surface of the regulating portion 152 in the drawing. During this operation, the operator feels resistance (a click feeling) when the first regulated portion 360 climbs over the regulating portion 152, thereby recognizing that the detection gear 300 has moved to the vicinity of the initial position. can be done. Further, even if the operator has turned the detection gear 300 too far from the initial position to the downstream side in the counterclockwise direction in the figure, if the operator releases the detection gear 300 at that position, the urging force of the torsion spring 500 will cause the detection gear 300 to move. can be returned to its initial position.

When the detection gear 300 rotates to the final position, the second projection 382 comes into contact with the upstream side surface of the movement restricting portion 210, as indicated by the dashed line in FIG. Gear 300 is positioned at the final position.

It should be noted that the effects described above can also be exhibited similarly in the large capacity type as shown in FIGS. 11 to 13. FIG. When the detection gear 300 rotates to the final position, the first projection 381 comes into contact with the upstream side surface of the movement restricting portion 210 as indicated by the dashed line in FIG. Gear 300 is positioned at the final position.

Next, the operation of the transmission gear 400 and the detection gear 300 when using a new developing cartridge 8 will be described.
As shown in FIGS. 14A to 14C, in the initial state, that is, when the developing cartridge 8 is new, the small-diameter gear portion 450 of the transmission gear 400 is connected to the first gear tooth portion 332 of the detection gear 300. away from The large diameter gear portion 440 of the transmission gear 400 is also separated from the second gear tooth portion 352 of the detection gear 300 . Further, the third rib 371 of the detection gear 300 is urged by the torsion spring 500 clockwise (in the direction opposite to the rotation direction), so that the detection gear 300 is located at the initial position. The initial position is an example of the first position, and the second rib 340 is positioned on the rotational locus of the first rib 460 when the detection gear 300 is positioned at this initial position. Further, when the detection gear 300 is located at the initial position, the first gear tooth portion 332 is arranged outside the rotational locus of the small-diameter gear portion 450 .

When the driving force is input to the developing cartridge 8 from the initial state, the transmission gear 400 rotates clockwise in the drawing, and the first rib 460 rotates clockwise in the drawing. After that, as shown in FIGS. 15(a) to 15(c), the first rib 460 contacts the second rib 340 of the detection gear 300 and pushes the second rib 340 against the biasing force of the torsion spring 500. When pressed downward in the drawing, the detection gear 300 rotates by a predetermined amount, and the first gear tooth portion 332 of the detection gear 300 meshes with the small-diameter gear portion 450 of the transmission gear 400, thereby shifting to FIGS. As shown, the detection gear 300 is further rotated by a predetermined amount. The position of the detection gear 300 shown in FIG. 15(b) corresponds to the second position.

After that, as shown in FIGS. 17A to 17C, after the small diameter gear portion 450 is disengaged from the first gear tooth portion 332, the large diameter gear portion 440 meshes with the second gear tooth portion 352 of the detection gear 300. As a result, the detection gear 300 is further rotated by a predetermined amount. The position of the detection gear 300 shown in FIG. 17(b) corresponds to the third position. When the detection gear 300 is at a predetermined position between the second position and the third position, the torsion spring 500 contacts the fourth rib 372 of the spring engaging portion 370 and rotates the fourth rib 372 in the rotational direction. force on. Specifically, after the upstream end of the first gear tooth portion 332 in the rotational direction reaches the small diameter gear portion 450 , the downstream end portion of the second gear tooth portion 352 in the rotational direction is connected to the large diameter gear. Until it engages with the portion 440, the detection gear 300 is urged in the rotational direction. As a result, after the first gear tooth portion 332 is disengaged from the small diameter gear portion 450, the biasing force of the torsion spring 500 pushes the second gear tooth portion 352 of the detection gear 300 toward the large diameter gear portion 440. The two-gear tooth portion 352 and the large-diameter gear portion 440 can be reliably meshed.

More specifically, while the detection gear 300 rotates from the position shown in FIG. 15B to the position shown in FIG. When the detection gear 300 reaches the position shown in FIG. 16B, the torsion spring 500 contacts the corner of the spring engaging portion 370 on the upstream side in the rotational direction. As a result, the direction of the biasing force applied by the torsion spring 500 to the spring engaging portion 370 is switched, and the detection gear 300 is biased counterclockwise (rotational direction) in the drawing by the torsion spring 500 .

After that, as shown in FIGS. 18(a) to (c), the detection gear 300 rotates while its second gear tooth portion 352 is in mesh with the large-diameter gear portion 440, and as shown in FIGS. As shown in (c), when the mesh is disengaged, it stops at the final position. At this time, the torsion spring 500 contacts the upstream side in the rotation direction of the second rib 340 of the detection gear 300, and urges the detection gear 300 downstream in the rotation direction. As a result, as shown in FIG. 10B, the second protrusion 382 of the detection gear 300 is pressed against the movement restricting portion 210, so that the detection gear 300 is held at the final position. Note that the final position corresponds to the fourth position. At the fourth position, the second gear tooth portion 352 is arranged outside the rotational trajectory of the large diameter gear portion 440 .

Further, in this embodiment, as shown in FIGS. 17A to 17C, the second gear tooth portion 352 is positioned before the second extension wall 301C of the detection protrusion 301 contacts the actuator 22. It is designed to mesh with 440. As a result, the driving force input from the transmission gear 400 to the detection gear 300 due to the meshing of the gear teeth can be used to strongly push the actuator 22 with the detection protrusion 301, so that the actuator 22 can be operated satisfactorily. .

Note that the above-described operation is carried out in substantially the same way even in the case of the large capacity type, as shown in FIGS. However, since the operation of the torsion spring 500 is somewhat different, the operation will be described below.

As shown in FIG. 20(b), when the detection gear 300 is in the initial position, that is, the first position, the torsion spring 500 engages with the third rib 371 and moves the third rib 371 counterclockwise as shown. energized around. After that, as shown in FIG. 21(b), when the detection gear 300 starts to rotate clockwise, the third rib 371 resists the urging force of the torsion spring 500 and pushes the torsion spring 500 upward. push to the right.

After that, as shown in FIG. 22B, when the third rib 371 is separated from the torsion spring 500, the torsion spring 500 is supported by the outer peripheral surface of the arcuate wall 341 connecting the third rib 371 and the second rib 340. As a result, the urging force is directed toward the center of the detection gear 300 . Then, as shown in FIG. 23(b), at the timing when the gear meshing between the transmission gear 400 and the detection gear 300 switches from the first gear tooth portion 332 to the second gear tooth portion 352, the torsion spring 500 is moved to the second gear tooth portion. 2 rib 340 is engaged from the rotational direction upstream side. As a result, the torsion spring 500 urges the second rib 340 toward the downstream side in the rotation direction, so that the movement of the second gear tooth portion 352 is assisted by the urging force, and meshes with the large-diameter gear portion 440 reliably.

Thereafter, as shown in FIGS. 24(b) and 25(b), the torsion spring 500 is flexed rearward by the fourth rib 372 of the detection gear 300, and then the fourth rib 372 rotates at the final position. By contacting the surface on the upstream side in the direction, the detection gear 300 is urged to the downstream side in the rotational direction. As a result, as shown in FIG. 13B, the first protrusion 381 of the detection gear 300 is pressed against the movement restricting portion 210, so that the detection gear 300 is held at the final position.

The detection protrusion 301 is used to allow a control device (not shown) to determine whether the developing cartridge 8 is new and to determine the specifications. The new product determination and specification determination in this embodiment will be briefly described below.

The detection protrusion 301 is arranged at an initial position as an example of the first position shown in FIG. 14(a) when the developing cartridge 8 is in a new state. The outer peripheral wall 301A of the detecting protrusion 301 can come into contact with the actuator 22 provided swingably in the image forming apparatus main body when the new developing cartridge 8 is installed in the image forming apparatus main body. That is, the first protrusion 301 has a first portion 301D that contacts the actuator 22 of the image forming apparatus main body when the detection gear 300 is at the first position. As shown in FIG. 3A, when the outer peripheral wall 301A of the detection projection 301 abuts against the actuator 22, the actuator 22 swings rearward. A controller (not shown) recognizes that the developing cartridge 8 is attached to the main body of the image forming apparatus.

It should be noted that the detection of the rearward swinging of the actuator 22 means that the actuator 22 positioned between the light-emitting element and the light-receiving element of the optical sensor swings rearward and is removed, turning the optical sensor ON. , or conversely, it may be detected that the light is blocked by the actuator 22 that has swung rearward, that is, that the optical sensor is turned off. In the following description, it is assumed that the rearward swinging of the actuator 22 is detected when the optical sensor is turned on.

Thereafter, when print control is started and a driving force is input to the developing cartridge 8, the detection projection 301 rotates counterclockwise as shown in FIG. 15(a). When the outer peripheral wall 301A of the detection projection 301 is disengaged from the actuator 22 by this rotation, the actuator 22 returns to its original position (the position indicated by the two-dot chain line in FIG. 3), as shown in FIG. 16(a). It enters between the first extension wall 301B and the second extension wall 301C by the biasing force of a spring (not shown), returns to its original position, and turns off the optical sensor.

After that, as shown in FIG. 18(a), the actuator 22 is pushed rearward by the second extension wall 301C of the detection projection 301, and then, as shown in FIG. The optical sensor is turned ON again by being supported by the . That is, the detection protrusion 301 has a second portion 301E that contacts the actuator 22 of the image forming apparatus main body when the detection gear 300 is at the fourth position. In this way, when the signal of the optical sensor switches from ON→OFF→ON after the driving force is input to the developing cartridge 8, the control device determines that the attached developing cartridge 8 is in a new state. do.

Further, when the detection projection 301 is positioned at the final position as an example of the fourth position where the actuator 22 is again supported by the outer peripheral wall 301A, the detection gear 300 and the gear upstream thereof (upstream in the direction of transmission of driving force) is disconnected, and the position of the detection protrusion 301 is maintained at the final position. Therefore, when the once-used developing cartridge 8 is attached to the main body of the image forming apparatus, the outer peripheral wall 301A of the detecting projection 301 positioned at the final position pushes the actuator 22 rearward, thereby turning on the optical sensor. Thereafter, print control is started, and even if the driving force is input to the developing cartridge 8, the detection projection 301 does not move from the final position. becomes. In this case, the control device determines that the installed developer cartridge 8 is in an old state (used at least once).

Also, the interval (angle) in the rotational direction from the first extension wall 301B to the second extension wall 301C of the detection projection 301 is set according to specifications. As a result, for example, when the optical sensor is turned off for the first time, the control device can determine that the cartridge body 100 is of the standard type in which the amount of toner stored in the cartridge body 100 is standard. can. Further, when the OFF time is the second time longer than the first time, the control device can determine that the toner amount is larger than the standard type.

Specifically, for example, as shown in FIG. 4A, when the amount of toner is standard, the distance from the first extension wall 301B to the second extension wall 301C is the predetermined first distance. there is In other words, when the toner amount is standard, a line segment L1 connecting the first end A1 of the outer peripheral wall 301A and the second axis CL2, and the second end A2 of the outer peripheral wall 301A and the second axis CL2 are The angle formed by the connecting line segment L2 is the first angle θ1. The first angle θ1 can be set, for example, within a range of 97° or more and 99° or less. Note that θ1 is 98° in this embodiment.

On the other hand, as shown in FIG. 5A, in the case of a large-capacity type in which the amount of toner is larger than the standard, the distance from the first extension wall 301B to the second extension wall 301C is larger than the first distance. The second interval is large. In other words, in the case of a type with a larger amount of toner than the standard type, the angle formed by the line segment L1 and the line segment L2 is a second angle θ2 that is larger than the first angle θ1.

The second angle θ2 can be set, for example, within a range of 188° or more and 190° or less. Contrary to the present embodiment, the angle of the standard type may be the second angle θ2, and the angle of the large capacity type may be the first angle θ1. Note that θ2 is 189° in this embodiment.

According to the above, the following effects can be obtained in this embodiment.
Since the detection gear 300 rotates while the small diameter gear portion 450 and the first gear tooth portion 332 are in mesh and while the large diameter gear portion 440 and the second gear tooth portion 352 are in mesh, for example, the second gear tooth Compared to a configuration without a portion, the amount of rotation of the detection gear 300 can be increased, and the amount of movement of the detection projection 301 can be increased, thereby enabling good detection of new products and specification detection. The rotation speed of the detection gear 300 changes when the engagement between the small diameter gear portion 450 and the first gear tooth portion 332 is switched to the engagement between the large diameter gear portion 440 and the second gear tooth portion 352, so this is utilized. It is also possible to detect new products and specifications.

Since the second gear tooth portion 352 meshes with the large diameter gear portion 440 before the second extension wall 301C of the detection projection 301 contacts the actuator 22, the first gear tooth portion 332 disengages from the small diameter gear portion 450 and then the actuator Reverse rotation of the detection gear 300 due to the biasing force from 22 can be suppressed.

The time from when the upstream end of the first gear tooth portion 332 in the rotational direction reaches the small diameter gear portion 450 until the downstream end portion of the second gear tooth portion 352 in the rotational direction engages with the large diameter gear portion 440 During this time, the torsion spring 500 urges the detection gear 300 downstream in the rotational direction. Therefore, after the first gear tooth portion 332 is disengaged from the small diameter gear portion 450 , the second gear tooth portion 352 can be reliably meshed with the large diameter gear portion 440 by the biasing force of the torsion spring 500 .

Since the torsion spring 500 urges the first regulated portion 360 of the detection gear 300 toward the regulating portion 152, the detection gear 300 can be favorably held at the initial position.

Since the torsion spring 500 engages with the spring engaging portion 370 between the first gear tooth portion 332 and the second gear tooth portion 352 in the axial direction, the biasing force of the torsion spring 500 causes the detection gear 300 to tilt. It is possible to prevent the first gear tooth portion 332 or the second gear tooth portion 352 from coming off the mating tooth.

At the final position, the second extension wall 301C of the detection projection 301 is located downstream of the upstream end of the arc wall 220 of the first gear cover 200 in the rotational direction. It is possible to suppress the formation of a gap between the second extension wall 301C and the upstream end of the circular arc wall 220 in the rotational direction. Therefore, it is possible to prevent the actuator 22 with which the detection protrusion 301 abuts from being caught in the gap.

The present invention is not limited to the above-described embodiments, and can be used in various forms as exemplified below.

Although the present invention is applied to the laser printer 1 in the above embodiment, the present invention is not limited to this, and may be applied to other image forming apparatuses such as copiers and multi-function machines.

Although the present invention is applied to the developing cartridge 8 in the above embodiment, the present invention is not limited to this. For example, when a developing device having a developing roller and a toner cartridge having a toner containing portion are separate components, the present invention may be applied to the toner cartridge.

In the above embodiment, gear teeth are used to transmit the driving force from the transmission gear to the detection gear. However, the present invention is not limited to this, and a friction member such as rubber or sponge may be provided instead of the gear teeth. .
Specifically, for example, as shown in FIG. A second friction member 353 is provided along a portion of the periphery and, instead of the second gear tooth portion 352, is provided along a portion of the periphery of the second toothless portion 351 to frictionally engage with the large-diameter gear portion 440. good too. Similarly, a friction member may be provided in place of the gear teeth of the transmission gear.

In the above-described embodiment, the detection projection is formed integrally with the detection gear, but the present invention is not limited to this, and the detection projection may be a separate part from the detection gear. may be used.

In the above embodiment, the detection protrusions are arc-shaped protrusions, but the present invention is not limited to this, and two detection protrusions separated in the rotational direction may be used.

In the above-described embodiment, the detection gear 300 is supported by the cap 150, but the present invention is not limited to this. You may let In this case, the filling port may be arranged on the side wall opposite to the side wall of the cartridge body 150 where the gear train such as the detection gear 300 is arranged.

In the above embodiment, the boss 155 that supports the detection gear 300 protrudes from the cap 150, but the present invention is not limited to this. good.

In the above embodiment, the torsion spring 500 was used as an example of the spring, but the present invention is not limited to this, and for example, a coil spring, a plate spring, or an elastic resin may be used.

In the above embodiment, the cylindrical portion 380 and the rotating shaft portion 310 are hollow inside, but the present invention is not limited to this, and the cylindrical portion and the rotating shaft portion may be solid. A portion of the rotating shaft portion 310 corresponding to the second toothless portion 351 may be partially cut. Further, the surface of the cylindrical portion 380 may be cut at a portion corresponding to the first toothless portion 331, for example. That is, the cylindrical portion 380 may be arc-shaped.
Although the detection gear 300 is configured to mesh with the transmission gear 400 supported by the agitator, it may be configured to mesh with the idle gear.
The second extension wall 301C does not have to be connected to the rotating shaft portion 310 . Also. A plurality of bosses may be arranged in place of the second extension wall 301C to serve as a substitute for the second extension wall.

8 developer cartridge 100 cartridge body 300 detection gear 301 detection projection 310 rotary shaft portion 352 second gear tooth portion 380 cylindrical portion 332 first gear tooth portion 400 transmission gear 440 large diameter gear portion 450 small diameter gear portion CL1 first axis line CL2 second axis

Claims (2)

a housing capable of accommodating a developer;
in the first gear,
a small diameter gear portion;
a large-diameter gear portion having a diameter larger than that of the small-diameter gear portion;
a first gear having
in the second gear,
a first columnar portion extending in the axial direction;
a second columnar portion extending in the axial direction, the second columnar portion having a diameter smaller than that of the first columnar portion;
a first engaging portion along a part of the peripheral surface of the first columnar portion, the first engaging portion being engageable with the small-diameter gear portion;
A second engaging portion along a part of the peripheral surface of the second columnar portion, arranged closer to the housing than the first engaging portion in the axial direction, and engaged with the large-diameter gear portion. a second engaging portion that can be combined;
a projecting portion movable together with the first engaging portion and the second engaging portion;
a second gear having
The developer cartridge according to claim 1, wherein the second engaging portion is capable of engaging with the large diameter gear portion after the first engaging portion and the small diameter gear portion are engaged with each other. a housing capable of accommodating a developer;
A first gear rotatable about a first axially extending axis,
a small diameter gear portion;
a large-diameter gear portion having a diameter larger than that of the small-diameter gear portion;
a first gear having
a second gear rotatable about a second axially extending axis,
a first engaging portion along a part of the peripheral surface of the second gear, the first engaging portion being engageable with the small-diameter gear portion;
A second engaging portion disposed closer to the housing than the first engaging portion in the axial direction and along a part of the peripheral surface of the second gear, wherein the second engaging portion is arranged in the rotational direction of the second gear a second engaging portion disposed at a position different from the first engaging portion and capable of engaging with the large diameter gear portion after the first engaging portion and the small diameter gear portion are engaged;
a projecting portion movable together with the first engaging portion and the second engaging portion;
a second gear having
A developer cartridge according to claim 1, wherein a rotational trajectory defined by the rotation of the second engaging portion is smaller than a rotational trajectory defined by the rotation of the first engaging portion.

Images