CN110498116B

CN110498116B - Go out convenient domestic birds, beasts and eggs bin of egg

Info

Publication number: CN110498116B
Application number: CN201910727796.3A
Authority: CN
Inventors: 王海森; 高学敏; 尤鹏鹏; 李涛; 孙益博; 李佳飞
Original assignee: Lu'an City I Luosheng Industrial Design Co ltd
Current assignee: Jingmen Jiaolong Food Co.,Ltd.
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2021-05-04
Anticipated expiration: 2039-08-08
Also published as: CN110498116A

Abstract

The invention provides a household egg storage box convenient for egg discharging, which belongs to the technical field of agricultural and sideline product packaging, and provides a device, which is convenient for egg storage and can better prolong the shelf life of eggs, and the household egg storage box comprises a rotating mechanism, a box body and an article placing plate, wherein the rotating mechanism is longitudinally arranged in the box body through a bearing, three article placing plates are longitudinally arranged in the box body at equal intervals, the rotating mechanism consists of a rotating head, a rotating rod and clamping blocks, the rotating head is connected above the rotating rod in a welding mode, the rotating rod is fixedly provided with the three clamping blocks, the middle of the article placing plate is provided with a bayonet, and twelve article placing holes are equidistantly arranged on the periphery of the article placing plate, the invention enables the eggs to be longitudinally and independently placed on the article placing plates through the article placing plate arranged in the storage box, and the article placing holes similar to the shape of the eggs are also arranged in the article placing plates, thereby preventing the eggshells from being, and the shelf life of the eggs can be prolonged to a certain extent.

Description

Go out convenient domestic birds, beasts and eggs bin of egg

Technical Field

The invention belongs to the technical field of agricultural and sideline product packaging, and particularly relates to a household egg storage box convenient for egg discharging.

Background

Eggs are one of the foods that we eat more frequently, and long-term storage thereof is a big problem.

In daily life, a large number of eggs are generally bought and stored at home for a long time, however, the eggs are known to have a long service life, and in order to prevent the deterioration of protein in the eggs, the following modes are generally adopted in the storage process:

1. and (5) refrigerating in a refrigerator, and prolonging the shelf life of the eggs by utilizing the low-temperature condition in the refrigerator. However, the food stored in the refrigerator is too much, bacteria are easy to breed in the refrigerator, and eggs stored in the refrigerator are very easy to be invaded by the bacteria.

2. When eggs are placed in rice, the powder will more or less penetrate into the interstices of the shell of the egg, thereby blocking the passage of bacteria into the interior of the egg, and the rice will provide the egg with a drier environment relative to air, in which conditions bacteria are less likely to survive, and thus the egg is less likely to deteriorate. However, the surface of the bought eggs is dirty, and the eggs cannot be washed with water when stored, thereby affecting rice, and there is a high possibility that the eggs are damaged when the rice is needed.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a household egg storage box convenient for egg laying, which aims to solve the technical problems that: how to provide a device, conveniently store the egg to the shelf life of extension egg that can be better.

The purpose of the invention can be realized by the following technical scheme:

a household egg storage box convenient for egg discharging comprises a rotating mechanism, a box body and a storage plate; the rotating mechanism is longitudinally arranged in the box body through a bearing, one part of the upper end of the rotating mechanism penetrates through the top of the box body, the box body is a hollow cylinder, three object placing discs are longitudinally arranged in the box body at equal intervals, the object placing discs are disc-shaped and are clamped in the box body through grooves formed in the box body; the rotating mechanism is composed of a rotating head, a rotating rod and clamping blocks, wherein the rotating head is connected above the rotating rod in a welding mode, penetrates through a round hole formed in the middle of the box cover and is located above the box cover, and the rotating rod is fixedly provided with the three clamping blocks; the box body comprises a box cover, a box wall and a box bottom, wherein the box cover is fixedly arranged at the upper end of the box wall, and the lower end of the box wall is fixedly connected with the box bottom; the middle of the object placing plate is provided with a bayonet, and twelve object placing holes are equidistantly arranged on the periphery of the object placing plate.

The working principle of the invention is as follows: through being provided with in the box body and putting the thing dish to through setting up rotary mechanism, through rotatory mode, remove the egg of putting on the thing dish, make the egg can be taken out one by one, be provided with simultaneously and put the thing hole, every egg can independently be placed, prevents to cause the eggshell broken between the egg owing to the extrusion.

The bearing adopts a one-way bearing.

By adopting the structure, when the rotating mechanism rotates, the rotating mechanism can only rotate clockwise and unidirectionally, and can prevent the rotating mechanism from rotating anticlockwise due to misoperation, so that residual eggs are left on the turntable.

The fixture blocks are respectively positioned below the object placing discs, and from bottom to top, the distance between the fixture blocks and the object placing discs is gradually increased, and the fixture blocks are rectangular blocks.

Structure more than adopting sets up to bigger and bigger through the distance from the bottom up with the fixture block with putting the thing dish, can ensure that the fixture block can block in proper order in putting the bayonet socket of thing dish when adjusting the rotary rod height to when using, three put can independent work, mutual noninterference between the thing dish.

The middle of the box cover is provided with a round hole, and twelve marks are arranged around the round hole at equal intervals.

The object placing holes are tapered holes formed in the periphery of the object placing disc, and silica gel drying agents are filled in the holes.

The object placing hole is of a conical structure, is similar to an egg in shape, can clamp the egg, is filled with a silica gel drying agent in the object placing hole, and can play a role in drying and protecting the egg.

The rotary head comprises a lifting rotary head and a rotary head, the lifting rotary head is located at the upper end of the rotary head and is in threaded connection with the rotary head, a rectangular hole is formed in the lower end of the lifting rotary head, the rotary head is installed in a round hole formed in the box cover through a bearing, a rectangular through hole is longitudinally formed in the rotary head, and a pointer is arranged on the rotary head.

By adopting the structure, the height of the rod can be adjusted through the lifting rotary head, the rotary rod is driven to rotate through the rotating rotary head, and the pointer is arranged, so that the rotating angle can be ensured to be 30 degrees when the rotating rotary head rotates at every time.

The rectangular hole formed at the lower end of the lifting rotating head is larger than the rectangular through hole formed in the rotating head.

The bull stick comprises bull stick top, bull stick middle-end and bull stick bottom, and the bull stick top is a cuboid, fixed mounting is in the bull stick middle-end upper end, and the size on bull stick top is the same with the rectangle through-hole size of opening on the rotatory bull stick, the bull stick top passes the rectangle through-hole on the rotatory bull stick, and with go up and down the upper inner wall fixed connection who goes up the rectangular hole on the bull stick, the bull stick middle-end lower extreme passes through the rectangle connecting rod and connects the bull stick bottom, the bull stick bottom is passed through the bearing and is installed on the box bottom, and fixed mounting has the fixture block on the bull stick middle-end.

By dividing the turn bar into several segments and connecting them by rectangular links, the length of the turn bar can be changed without affecting the turning function of the turn bar.

And the inner wall of the box wall is also provided with an activated carbon layer.

The active carbon layer is arranged on the inner wall of the box body, so that peculiar smell in the box body can be removed.

The object taking hole is provided with a baffle, the upper part of the baffle is movably arranged above the object taking hole through a rotating shaft, and the two ends of the rotating shaft are respectively connected with the inner side wall of the box wall through torsion springs.

Through setting up the baffle, can seal the thing hole of getting to can reduce inside external bacterium flow direction fit.

Compared with the prior art, the invention has the following advantages:

1. through being provided with in the box body and putting the thing dish to through setting up rotary mechanism, through rotatory mode, remove the egg of putting on the thing dish, make the egg can be taken out one by one, be provided with simultaneously and put the thing hole, every egg can independently be placed, prevents to cause the eggshell broken between the egg owing to the extrusion.

2. Set to more and more big through the distance from the bottom up with the fixture block with putting the thing dish, can ensure that the fixture block can block in proper order in putting the bayonet socket of thing dish when adjusting the rotary rod height to when using, three put can independent work, mutual noninterference between the thing dish.

3. The object placing hole is of a conical structure, is similar to an egg in shape, can clamp the egg, is filled with a silica gel drying agent in the object placing hole, and can play a role in drying and protecting the egg.

4. The active carbon layer is arranged on the inner wall of the box body, so that peculiar smell in the box body can be removed.

Drawings

FIG. 1 is a schematic view of a household egg storage case with convenient egg laying;

FIG. 2 is a front view of a household egg storage case with ease of egg laying;

FIG. 3 is a top view of a household egg storage case with ease of egg laying;

FIG. 4 is a schematic view of a rotary mechanism in a home-use egg storage case for facilitating egg removal;

FIG. 5 is a cross-sectional view of a turn in a home-use egg storage case for facilitating egg removal;

FIG. 6 is a front view of a turn bar in a home-use egg storage case for ease of egg removal;

FIG. 7 is a cross-sectional view of a barrel in a home-use egg storage case for ease of egg removal;

FIG. 8 is a schematic view of a tray for storing eggs in a household egg storage container for facilitating egg removal;

FIG. 9 is a schematic view of an installation structure of a baffle in a home-use egg storage case for facilitating egg production;

in the figure: 1-rotating mechanism, 101-rotating head, 101 a-pointer, 101 b-lifting rotating head, 101 c-rotating head, 102-rotating rod, 102 a-rotating rod top, 102 b-rotating rod middle, 102 c-rectangular connecting rod, 102 d-rotating rod bottom, 103-clamping block, 2-box body, 201-box cover, 201 a-mark, 202-box wall, 202 a-object taking hole, 202 b-baffle, 202 c-active carbon layer, 202 d-groove, 203-box bottom, 3-object placing disk, 301-clamping opening, 302-object placing hole, 4-bearing, 5-torsion spring and 6-rotating shaft.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

Reference will now be made in detail to embodiments of the present patent, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present patent and are not to be construed as limiting the present patent.

In the description of this patent, it is to be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of describing the patent and for the simplicity of description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the patent.

In the description of this patent, it is noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can include, for example, fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in this patent may be understood by those of ordinary skill in the art as appropriate.

Referring to fig. 1-9, the present embodiment provides a household egg storage box with convenient egg discharging, which includes a rotating mechanism 1, a box body 2 and a tray 3; the rotating mechanism 1 is longitudinally arranged inside the box body 2 through a bearing 4, one part of the upper end of the rotating mechanism 1 penetrates through the top of the box body 2, the bearing 4 adopts a one-way bearing, the rotating mechanism 1 can rotate, and under the action of the bearing 4, the rotating mechanism 1 can only rotate clockwise, the box body 2 is a cylinder and is hollow, a plurality of object placing discs 3 are arranged inside the box body 2, in the embodiment, preferably, three object placing discs 3 are arranged, the object placing discs 3 are disc-shaped and are clamped inside the box body 2 through grooves 202d formed in the box body 2, and the three object placing discs 3 are longitudinally arranged at equal intervals; the rotating mechanism 1 is composed of a rotary head 101, a rotary rod 102 and a clamping block 103, wherein the rotary head 101 is connected above the rotary rod 102 in a welding mode, the rotary head 101 penetrates through a round hole formed in the middle of the box cover 201 and is located above the box cover 201, and the rotary rod 102 can be driven to rotate clockwise by rotating the rotary head 101 clockwise; three clamping blocks 103 are fixedly arranged on the rotating rod 102, the clamping blocks 103 are respectively positioned below the object placing disc 3, the distance between the clamping blocks 103 and the object placing disc 3 is gradually increased from bottom to top, the object placing disc 3 can be clamped by the clamping blocks 103, when the rotating rod 102 rotates, the object placing disc 3 can be driven to rotate by the clamping blocks 103, and the clamping blocks 103 are rectangular blocks; the box body 2 comprises a box cover 201, a box wall 202 and a box bottom 203, wherein the box cover 201 is fixedly arranged at the upper end of the box wall 202, the lower end of the box wall 202 is fixedly connected with the box bottom 203, a round hole is formed in the middle of the box cover 201, and a plurality of marks 201a are arranged around the round hole at equal intervals, in the embodiment, preferably, twelve marks are arranged, three grooves 202d and object taking holes 202a are formed in the box wall 202, the grooves 202d are positioned on the inner side wall of the box wall 202 and can be used for clamping the object placing plate 3, the object taking holes 202a are holes formed in the front surface of the box wall 202 and are respectively positioned above the grooves 202d, and an operator can extend hands into the box wall 202 through the object taking holes 202a to take out eggs stored in the box; a bayonet 301 is formed in the middle of the article placing disc 3, and a plurality of article placing holes 302 are formed in the periphery of the article placing disc 3 at equal intervals, in the embodiment, preferably twelve bayonet 301 are formed, wherein the bayonet 301 is rectangular and can be matched with the clamping block 103, the clamping block 103 is clamped on the bayonet 301, the clamping block 103 can drive the article placing disc 3 to rotate when rotating, the article placing holes 302 are tapered holes formed in the periphery of the article placing disc 3, silica gel drying agents are filled in the holes, the article placing holes 302 can be used for placing eggs, and by utilizing the characteristics of silica gel, on one hand, the eggshells can be prevented from being broken, on the other hand, the silica gel can also play a drying function, absorb moisture, and the probability that the eggs are invaded;

the rotary head 101 comprises a lifting rotary head 101b and a rotating rotary head 101 c; the lifting rotating head 101b is positioned at the upper end of the rotating head 101c and is connected with the rotating head 101c through threads, the rotating head 101c is pressed, when the lifting rotating head 101b is rotated clockwise, the lifting rotating head 101b moves upwards along the rotating head 101c, a rectangular hole is formed in the lower end of the lifting rotating head 101b, and the rotating rod 102 is fixedly connected to the upper inner wall of the rectangular hole; the rotating head 101c is installed in a circular hole formed in the box cover 201 through a bearing 4, a rectangular through hole is longitudinally formed in the rotating head 101c, the rectangular through hole is penetrated through by the rotating rod 102, when the lifting head 101b rotates clockwise, the lifting head 101b moves upwards along the rotating head 101c, the rotating rod 102 is driven to move upwards at the moment, a pointer 101a is arranged on the rotating head 101c, when the rotating head 101c rotates clockwise, the pointer 101a rotates along with the rotating head, the rotating head 101c rotates clockwise by 30 degrees each time until the pointer 101a faces the mark 201a, the object placing hole 302 is located right below the object taking hole 202a, and an operator takes eggs placed in the object placing hole 302 through the object taking hole 202 a; the rectangular hole formed at the lower end of the lifting rotating head 101b is larger than the rectangular through hole formed in the rotating head 101 c;

the rotating rod 102 consists of a rotating rod top end 102a, a rotating rod middle end 102b and a rotating rod bottom end 102d, the rotating rod top end 102a is a rectangular body and is fixedly installed at the upper end of the rotating rod middle end 102b, the size of the rotating rod top end 102a is the same as that of a rectangular through hole formed in the rotating head 101c, and the rotating rod top end 102a penetrates through the rectangular through hole in the rotating head 101c and is fixedly connected with the upper inner wall of the rectangular hole in the lifting rotating head 101 b; the lower end of the middle end 102b of the rotating rod is connected with the bottom end 102d of the rotating rod through a rectangular connecting rod 102c, the bottom end 102d of the rotating rod is arranged on the box bottom 203 through a bearing 4, when the lifting head 101b rotates clockwise, the lifting head 101b moves upwards along the rotating head 101c and drives the middle end 102b of the rotating rod to move upwards along the rectangular connecting rod 102c, so that the height of the middle end 102b of the rotating rod can be changed, a fixture block 103 is fixedly arranged on the middle end 102b of the rotating rod, when the middle end 102b of the rotating rod is at the lowest point, the lowest fixture block 103 is buckled with the lowest object placing disk 3, other two fixture blocks 103 are separated from the two object placing disks 3, after rotating clockwise for 101 circles, the middle fixture block 103 is buckled with the middle object placing disk 3, other two fixture blocks 103 are loosened from the two object placing disks 3, after rotating clockwise for 101 circles, the highest fixture block 103 is buckled with the highest object placing disk 3, the other two clamping blocks 103 are separated from the two object placing discs 3, and only when the clamping blocks 103 are clamped with the object placing discs 3, the rotating rod 102 can drive the object placing discs 3 to rotate through the clamping blocks 103;

the inner wall of the box wall 202 is also provided with an activated carbon layer 202c, and the activated carbon layer 202c can play a role in eliminating peculiar smell in the box body 2;

the article taking hole 202a is provided with a baffle 202b, the upper part of the baffle 202b is movably arranged above the article taking hole 202a through a rotating shaft 6, two ends of the rotating shaft 6 are respectively connected with the inner wall of the box wall 202 through a torsion spring 5, the baffle 202b is pushed by a hand, at the moment, the baffle 202b can rotate around the rotating shaft 6, a user can stretch the hand into the box body 2 to take out eggs, after the pushing force to the baffle 202b disappears, under the action of the torsion spring 5, the baffle 202b is tightly attached to the inner wall of the box wall 202, and the article taking hole 202a is completely covered.

The working principle of the invention is as follows:

1. the storage box is placed in a dry and dark environment, and the position of the storage box is ensured to be horizontal;

2. the bought eggs are placed in the article placing holes 302 through the article taking holes 202a, before the egg is placed, the lifting rotary head 101b is rotated anticlockwise firstly, so that the rectangular connecting rod 102c is tightly contacted with the bottom end 102d of the rotary rod, at the moment, the lowermost fixture block 103 is buckled with the lowermost article placing plate 3, and the other two fixture blocks 103 are separated from the two article placing plates 3; rotating the rectangular connecting rod 102c by 30 degrees to enable the top end 102a of the rotating rod to be opposite to the next mark 201a, vertically placing the eggs into the article placing holes 302 from the lowermost article taking hole 202a with the big ends facing upwards, rotating the rectangular connecting rod 102c again to 30 degrees, placing the eggs into the article placing holes 302 through the article taking holes 202a, and rotating the rectangular connecting rod 102c for one circle to fully place the article placing holes 302 on the lowermost article placing plate 3 with the eggs; then, the lifting rotary head 101b is rotated clockwise for one turn, at this time, the middle fixture block 103 is buckled with the middle storage plate 3, the other two fixture blocks 103 are separated from the two storage plates 3, the operation of rotating the rectangular connecting rod 102c is repeated, and the middle storage plate 3 is filled with eggs; rotating the lifting rotary head 101b clockwise one turn again, repeating the steps, filling the uppermost tray 3 with eggs, and then rotating the lifting rotary head 101b counterclockwise to make the rectangular connecting rod 102c tightly contact with the bottom end 102d of the rotary rod, and the lowermost fixture block 103 buckle with the lowermost tray 3;

3. when eggs need to be taken out, a user extends hands through the article taking hole 202a and pushes the baffle plate 202b to take the eggs out of the article placing hole 302; when eggs need to be taken, the rectangular connecting rod 102c is rotated by 30 degrees, the top end 102a of the rotating rod faces the next mark 201a, so that the eggs can be taken out continuously, and the eggs can be taken out continuously by repeating the steps;

4. when all the eggs on the lowest tray 3 are taken out, at the moment, the lifting rotary head 101b is rotated clockwise for a circle, at the moment, the rotary rod 102 is lifted, the middle clamping block 103 is buckled with the tray 3 at the middle position, at the moment, the step S3 is repeated, and the eggs are taken out;

5. when all the eggs on the intermediate tray 3 are picked up, the elevating/lowering head 101b is rotated clockwise for one turn, the rotating rod 102 is then raised again, and the uppermost latch 103 is engaged with the uppermost tray 3, and at this time, the step S3 is repeated to pick up the eggs.

Has the advantages that:

according to the egg storage box, the storage box is specially used for storing eggs, meanwhile, the storage tray is arranged in the storage box, and the storage holes similar to the eggs in shape are also formed in the storage tray, so that the eggs can be longitudinally and independently placed on the storage tray, egg shells can be prevented from being damaged due to collision among the eggs, and the quality guarantee period of the eggs can be prolonged to a certain extent; the active carbon layer is arranged in the box body, so that peculiar smell in the box can be absorbed; the silica gel drying agent is filled in the storage hole, so that the effects of drying and protecting eggs can be achieved.

Although the preferred embodiments of the present patent have been described in detail, the present patent is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present patent within the knowledge of those skilled in the art.

Claims

1. A household egg storage box convenient for egg discharging is characterized by comprising a rotating mechanism (1), a box body (2) and a storage plate (3); the rotary mechanism (1) is longitudinally arranged in the box body (2) through a bearing (4), one part of the upper end of the rotary mechanism (1) penetrates through the top of the box body (2), the box body (2) is a hollow cylinder, three object placing discs (3) are longitudinally arranged in the box body (2) at equal intervals, the object placing discs (3) are disc-shaped, and are clamped in the box body (2) through grooves (202d) formed in the box body (2); the rotating mechanism (1) is composed of a rotary head (101), a rotary rod (102) and a clamping block (103), wherein the rotary head (101) is connected above the rotary rod (102) in a welding mode, and the rotary head (101) penetrates through a round hole formed in the middle of the box cover (201) and is positioned above the box cover (201); three clamping blocks (103) are fixedly arranged on the rotating rod (102); the box body (2) comprises a box cover (201), a box wall (202) and a box bottom (203), wherein the box cover (201) is fixedly arranged at the upper end of the box wall (202), and the box bottom (203) is fixedly connected to the lower end of the box wall (202); a bayonet (301) is arranged in the middle of the object placing plate (3), and twelve object placing holes (302) are arranged on the periphery of the object placing plate at equal intervals; the rotating head (101) comprises a lifting rotating head (101b) and a rotating head (101c), the lifting rotating head (101b) is located at the upper end of the rotating head (101c) and is connected with the rotating head (101c) through threads, a rectangular hole is formed in the lower end of the lifting rotating head (101b), the rotating head (101c) is installed in a round hole formed in the box cover (201) through a bearing (4), a rectangular through hole is longitudinally formed in the rotating head (101c), and a pointer (101a) is arranged on the rotating head (101 c); the rectangular hole formed at the lower end of the lifting rotating head (101b) is larger than the rectangular through hole formed in the rotating head (101 c); the rotating rod (102) is composed of a rotating rod top end (102a), a rotating rod middle end (102b) and a rotating rod bottom end (102d), the rotating rod top end (102a) is a rectangular body and is fixedly installed at the upper end of the rotating rod middle end (102b), the size of the rotating rod top end (102a) is the same as that of a rectangular through hole formed in the rotating head (101c), the rotating rod top end (102a) penetrates through the rectangular through hole in the rotating head (101c) and is fixedly connected with the upper inner wall of the rectangular hole in the lifting rotating head (101b), the lower end of the rotating rod middle end (102b) is connected with the rotating rod bottom end (102d) through a rectangular connecting rod (102c), the rotating rod bottom end (102d) is installed on the box bottom (203) through a bearing (4), and a clamping block (103) is fixedly installed on the rotating rod middle end (102 b); the object placing holes (302) are tapered holes formed in the periphery of the object placing disc (3), and silica gel drying agents are filled in the holes; the inner wall of the box wall (202) is also provided with an activated carbon layer (202 c); the box wall (202) is provided with an object taking hole (202a), the object taking hole (202a) is provided with a baffle (202b), the upper part of the baffle (202b) is movably arranged above the object taking hole (202a) through a rotating shaft (6), and the two ends of the rotating shaft (6) are respectively connected with the inner side wall of the box wall (202) through a torsion spring (5).

2. A domestic egg storage box for eggs conveniently discharging as claimed in claim 1, wherein said bearing (4) is a one-way bearing.

3. The household egg storage box convenient for egg discharging as claimed in claim 1, wherein the fixture blocks (103) are respectively located below the storage tray (3), and from bottom to top, the distance between the fixture blocks (103) and the storage tray (3) is gradually increased, and the fixture blocks (103) are rectangular blocks.

4. The household egg storage box convenient for egg laying as claimed in claim 1, wherein a round hole is formed in the middle of the box cover (201), and twelve marks (201a) are arranged around the round hole at equal intervals.