JPH0320948Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a disk cartridge in which a disk is rotatably housed in a disk case, and the hub constituting the disk is improved.

That is, FIGS. 1 and 3 show typical examples of the disk cartridge to which the present invention is applied, which basically consists of a disk case having a drive shaft insertion window 3 and a magnetic head insertion window 4. 1
and a disk 2 that is rotatably installed inside the disk case 1, and the disk 2 is a disk-shaped seat 9.
and a hub 10 that is integrally connected to the center of the seat 9 and faces the drive shaft insertion window 3. When loaded into the disk drive, the support shaft provided at the center of the hub 10 as shown in FIGS. 15 and 18. A support shaft 19 on the disk drive side is inserted into the insertion hole 14, and a drive shaft 20 on the disk drive side is engaged with an engaging portion 16 provided at one location on the outer periphery of the end face of the hub, thereby rotationally driving the disk 2. It's summery.

In this case, it is necessary to correctly center the hub 10 with respect to the support shaft 19 in order to prevent the track from shifting.
9 are provided with circumscribed surfaces 32, 32 that are in line contact at two points P ₁ and P ₂ , and when the disk 2 is driven to rotate, the circumscribed surfaces 32, 32 are brought into contact with the spindle 19, and the hub is attached to the spindle 19. 10 is proposed to be properly aligned.

However, the circumscribed surfaces 32, 32, which require dimensional accuracy in micron units, are formed on vertical surfaces. In other words, the circumscribed surface 32,3
2, the spindle insertion hole 14 does not have a perfect circular shape, and the peripheral wall portion 31 having the circumscribed surfaces 32, 32 inevitably becomes thicker in the radial direction than other peripheral wall portions. Therefore, heat shrinkage deformation during plastic molding due to the difference in wall thickness, so-called sink marks, is likely to occur on the critical circumscribed surfaces 32, 32, making it impossible to ensure sufficient smoothness and vertical accuracy. The centering accuracy of 10 was reduced.

In this respect, as long as the entire hub 10 is integrally molded at the same time, there will be a difference in wall thickness between the peripheral wall portion having the circumferential surfaces 32 and the other peripheral wall portions.
It was an unavoidable problem.

The hub 10 is divided into upper and lower halves, and an upper hub component 1 is formed.
2 and the lower hub structure 13 through the center hole 8 of the seat 9.
A hub 10 in which the peripheral edges of the hub 10 are clamped and joined together is conventionally known. However, even there, the peripheral wall of the spindle insertion hole 14 is connected to the upper and lower hub components 1.
It was simply molded integrally with either one of Nos. 2 and 13.

If the peripheral wall of the spindle insertion hole 14 is rationally divided into several parts, and the divided peripheral wall parts are integrally molded separately into the upper and lower hub components 12 and 13,
When the upper and lower hub components 12 and 13 are combined, if the support shaft insertion hole 14 can be formed by these peripheral wall portions,
Even if the peripheral wall portion 31 having the circumscribed surfaces 32, 32 in question becomes thicker, there is room to improve the surface accuracy of the circumscribed surfaces 32, 32.

This is because the occurrence of sink marks during plastic molding is largely due to the difference in wall thickness with other parts, and even if the problem part is thick, if it is equal to the other parts, it can be improved considerably by changing the molding conditions. Since the upper and lower hub components 12 and 13 are molded separately, it is also possible to mold one of them using a plastic material that has excellent molding accuracy, instead of using the respective molding materials. During mold molding, the peripheral wall portion 31, which inevitably becomes thicker, is provided with a space 3 for relief, which will be described later.
This is because it is also possible to add shape deformation, such as by providing the peripheral wall portion 31 to adjust the thickness of the peripheral wall portion 31.

These are only possible on the premise that the hub 10 adopts a specification in which the upper and lower hub components 12 and 13, which are separately molded, are later mechanically joined together. The next problem is how to rationally divide the peripheral wall of the spindle insertion hole 14, mold the upper and lower hub components 12 and 13 separately, and then form the spindle insertion hole 14 with the divided peripheral wall parts in the combined state. It depends on whether you configure it or not.

The present invention was proposed based on this idea, and includes upper and lower hub structures 12 and 13 made of plastic that are joined together with the hub 10 clamping the peripheral edge of the central hole 8 of the seat 9. In a disk cartridge consisting of
1 and the remaining peripheral wall portion, and integrally mold the peripheral wall portion 31 on one of the lower hub components 13 and the remaining peripheral wall portions on the other upper hub component 12, thereby forming the The purpose is to improve the surface precision of the circumscribed surfaces 32, 32.

In order to achieve the above object, the present invention provides upper and lower hub structures 12, 1 which are separately molded as shown in the figure.
In the disc cartridge, the lower hub component 13 has a hole 29 in the center, and the inner part of the hole 29 A peripheral wall portion 31 constituting a part of the inner periphery of the spindle insertion hole 14 is formed to protrude on the peripheral surface with a certain extent in the circumferential direction; Two flat circumscribed surfaces 32, 32 that are in line contact with the surface at two points P ₁ and P ₂ are formed perpendicularly with a predetermined angle θ; Hub structure 13
a hole 39 in the center into which the peripheral wall portion 31 of the upper hub structure 12 fits;
A partial boss 40 that fits into the cutout hole 29 of the lower hub structure 13 and forms part of the inner circumference of the spindle insertion hole 14
is formed with a predetermined expansion angle in the circumferential direction. When the upper and lower hub members 12 and 13 are joined together, the peripheral wall portion 3 of the lower hub member 13
1 and both circumferential end surfaces of the partial boss 40 of the upper hub structure 12, vertically penetrating slits 48, 448 are required to be formed therein. do.

According to the above configuration, the upper and lower hub components 12,
13 in an overlapping state from above and below, the circumscribed surfaces 32, 3 provided on the lower hub structure 13
The peripheral wall portion 31 having the upper hub structure 12
The partial boss 40 (remaining peripheral wall portion of the spindle insertion hole 14) of the upper hub structure 12 fits into the cutout hole 39 of the lower hub structure 13 from below through the slits 48, 48. It fits into the peripheral wall portion 31 without abutting and interfering with it. In this way, when the hub 10 is obtained by inseparably joining the upper and lower hub components 12 and 13, the peripheral wall portion 31 and the partial boss 4
0 constitutes the peripheral wall of the spindle insertion hole 14, and a spindle 19 on the disk drive side can be inserted into this spindle insertion hole 14.

According to the present invention, the peripheral wall portion 31 having the circumscribed surfaces 32, 32 in question is provided on the lower hub component 13.
is molded separately from the other peripheral wall portion (partial boss 40) that constitutes the spindle insertion hole 14.
Therefore, even if the circumferential wall portion 31 has to be thickened in the radial direction because the circumscribed surfaces 32, 32 should be formed as flat vertical surfaces with a predetermined included angle θ, the circumferential wall portion 31 There is a limit to the extent of the circumferential direction, and since it is molded separately from the upper hub component 12, the thickness difference between the peripheral wall portion 31 and other parts is created as much as possible only in the lower hub component 13. It is possible to take special considerations such as adjusting the wall thickness of the peripheral wall portion 31 by providing a space 33 for wall relief, which will be described later, as shown in the embodiment to prevent undercuts from occurring on the molding die. Together, these improve the surface accuracy, including the planar accuracy and vertical accuracy, of the circumscribed surfaces 32, 32, and the alignment accuracy of the hub 10 with respect to the support shaft 19 can be stably ensured, contributing to the prevention of track misalignment. be able to.

Furthermore, when the upper and lower hub components 12 and 13 are combined, slits 48 and 48 are provided between the peripheral wall portion 31 and the partial boss 40 to separate them in the circumferential direction.
was made to occur. Therefore, these slits 4
8 and 48 ensure smooth fitting between the peripheral wall portion 31 and the partial boss 40 using the punched holes 29 and 39. Moreover, the slits 48, 48 are located at the hub 10.
This reduces the weight itself, improves the rotation performance of the hub 10, and helps stabilize the weight balance in the circumferential phase, thereby ensuring stable rotation of the hub 10 without whirling around. .

The details will be explained below based on the drawings.

In FIGS. 1 and 2, the disc cartridge of the present invention is made of plastic upper and lower cases 1.
The disc case 1 is made up of a flat hard disk case 1 in which the lids a and 1b are joined together by ultrasonic welding at several points, and a magnetic disk 2 is rotatably installed inside the disk case 1.

The disk case 1 has a drive shaft insertion window 3 located approximately in the center near the front thereof, and a magnetic head insertion window 4 located in front of the drive shaft insertion window 3 and long from front to back.
, a small-diameter index hole 5 located at the rear of the drive shaft insertion window 3, positioning holes 6, 6 of irregular shapes on the top and bottom surfaces located on the front left and right, and opening and closing members located on the front left and right and mounted inside the case. It has write protection holes 7, 7 that are operated, and these windows and holes are provided vertically through each other.

The disk 2 consists of a disk-shaped magnetic sheet 9 having a circular hole 8 in the center, and a hub 10 that is clamped around the peripheral edge of the central hole 8 of the sheet 9.

In FIGS. 11 and 12, the hub 10 is an upper hub component 12 separately molded in plastic from acetal resin or arylate resin.
and a lower hub structure 13 are integrally connected in the manner described later, and has a spindle insertion hole 14 in the center, and annular guide grooves 15, 15 on the upper and lower outer end surfaces around the hub center P. A rib 16 is formed in a concave manner on the outer periphery and crosses each guide groove 15 at one location in the circumferential direction.
(hereinafter referred to as the engaging portions 16) are formed at vertically symmetrical positions.

12 and 18, on the disk drive side, a support shaft 19 is provided high in the center on the hub receiving surface 18 of the hub holder 17, and a drive shaft 20 is protruded low at one location on the outer periphery. A cone-shaped collet 21 facing the hub holder 17 is provided, and when the disc cartridge of the present invention is loaded into the disc drive, the receiving surface 18 of the hub holder 17 and the tip of the collet 21 are inserted through the drive shaft insertion window 3 of the disc case 1. The upper and lower end surfaces of the hub 10 are clamped and held by the support shaft 1.
9 enters the support shaft insertion hole 14, and the drive shaft 20 engages in the guide groove 15. As the hub holder 17 rotates, the drive shaft 20 that has entered the guide groove 15 comes into contact with the engaging portion 16 as shown in FIG.
This is the basic form in which the motor is rotationally driven. It is anticipated that the proposed disk cartridge will use the sheet 9 that can record on both sides, and that the disk case 1 will be used upside down.
0 is also basically vertically symmetrical. Needless to say, it may be used only on one side.

Next, the upper and lower hub components 1 that constitute the hub 10
2 and 13, in FIGS. 5, 9, and 17, at positions near the outer periphery of the opposing surfaces of both 12 and 13, there is a seat annular clamping surface 23 that is butted against each other. 24 is hub center P
It is formed concentrically and protrudingly. On the upper surface of the lower hub structure 13, tall welding pins 25 and short seat positioning pins 26 are arranged alternately on the inner and outer circumferential lines concentric with the hub center P on the inner side of the tape clamping surface 24. The upper hub structure 12
A through hole 27 into which each welding pin 25 fits is transparently provided. Each sheet positioning pin 26 is slightly higher than the tape clamping surface 24, and the outer circumferential surface of the pin is located on the outer side of the welding pin 25 in the radial direction. When assembling the disk 2, first place the seat 9 on the upper surface of the lower hub structure 13, position the seat 9 by making the periphery of the seat center hole 8 circumscribe each positioning pin 26 as shown in FIG. Preferably, the peripheral edge of the center hole of the sheet 9 is adhesively fixed to the tape clamping surface 24 to prevent the sheet 9 from rotating, and then the upper hub structure 12 is superimposed on the lower hub structure 13, and each welding pin 25 is fixed. are guided into each through hole 27 so that the upper end of each welding pin 25 faces the upper end surface of the upper hub component 12, specifically, the guide groove 15, and the protrusion of each welding pin 25 is made as shown in FIG. The upper end portions are melted by ultrasonic welding and both hub components 12 and 13 are caulked and connected. In this state, the peripheral edge of the center hole of the seat 9 is connected to the seat clamping surface 2 of both hub components 12 and 13.
3, 24, both hub components 12, 1
3, a gap g is formed on the outer peripheral end side of the sheet clamping surfaces 23 and 24. Therefore, even if there is a failure in the sheet holding by both hub components 12 and 13, this will not affect the sheet portion coming out from the hub 10. Furthermore, since each positioning pin 26 is located outside each welding pin 25, even if the melting margin of each welding pin 25 during welding wraps around between both hub components 12 and 13, it does not reach the periphery of the center hole of the seat 9. First, this also prevents the sheet 9 from being deformed.

In FIGS. 3 to 6, the lower hub structure 13 has a hole 29 in the center, and the hole 29
A fan-shaped wall 30 extending 150 degrees in the circumferential direction is formed to project from a part of the inner periphery of the hole toward the center of the hole. is erected upwards.

Two circumscribed surfaces 32 are provided on the inner surface of the peripheral wall portion 31 and are in line contact with the circular outer peripheral surface of the support shaft 19 at two points P ₁ and P ₂ .
32 is formed perpendicularly with a constant angle θ (90° in the illustrated example), and these circumscribed surfaces 32, 32 are symmetrical with respect to the axis of symmetry L passing through the hub center P, and the upper and lower surfaces of the hub 10 It has a vertical length that approximately corresponds to the width.
On the upper and lower surfaces of the overhanging wall 30, the peripheral wall portion 31
The guide groove 1 is formed on the outside of both circumscribed surfaces 32, 32.
A space 33 for meat relief between the inner wall portion 15a of 5,
33 respectively from the top and bottom, the middle part is the inner wall part 1
5a, and the thickness of the peripheral wall portion 31 is adjusted in this space 33 to prevent sink marks from occurring particularly on the circumscribed surfaces 32, 32 during plastic molding.

An arm 36 curved in an arc with the hub center P as the center of curvature is extended in a cantilevered manner from one end surface 35 of the projecting side of the overhanging wall 30 .
A block-shaped movable member 37 is integrally molded at the free end of the movable member 37. This movable member 37 is located at a position facing the peripheral wall portion 31, has a vertical length approximately corresponding to the vertical width of the hub 10, and has a protruding curved surface 38 formed on the inner surface facing the center of the hub. 38
makes a line contact with the outer periphery of the support shaft 19 at one point _P3 .

7 to 10, the upper hub structure 12 has a hole 39 in the center into which the peripheral wall portion 31 of the lower hub structure 13 fits, and A partial boss 40 that fits into the hole 29 of the side hub structure 13 projects in the circumferential direction with an expanding angle of 180 degrees. This part boss 4
0 constitutes the remaining peripheral wall portion of the spindle insertion hole 14 excluding the peripheral wall portion 31, and includes the hub 10.
A series of inner wall portions 15a constituting the inner wall of the lower guide groove 15, and a series of inner wall portions 15a that protrude toward the center of the hub from both ends of the inner wall portion 15a in the circumferential direction and forming a part of the spindle insertion hole 14. It consists of a first constituent wall 41, a second constituent wall 42, and a recess 43 formed between both constituent walls 41, 42 and penetrating in the vertical direction. The first constituent wall 41 has an L-shaped cross-sectional surface, and has a downwardly opening recessed groove 44 that is partially arcuate in plan view, and the protruding inner end surface 45 of the grooved wall 41 It is formed into a partially arcuate concave curved surface that contacts the outer periphery of the support shaft 19, and the presence of the recessed groove 44 also aims to improve the molding accuracy of the concave inner end surface 45. Recessed spaces 46, 46 are formed in the second constituent wall 42 from above and below, and the protruding inner end surface 47 thereof is also formed into a partially arcuate concave curved surface that contacts the outer periphery of the support shaft 19. Each of the protruding inner end surfaces 45 and 47 of the first and second constituent walls 41 and 42 has a vertical length extending from the upper surface of the upper hub structure 12 to substantially the lower surface of the lower hub structure 13.

When the upper and lower hub components 12 and 13 are integrally connected in the manner described above, the intermediate portion of the cantilever arm 36 is connected to the first component wall 41 as shown in FIGS. 16 and 18.
The movable member 37 is inserted into the recessed groove 44 from below with an allowance for deformation in the radial direction, and the movable member 37 is also inserted into the recess 4 between the first and second constituent walls 41 and 42 with an allowance for deformation in the radial direction.
3. In this state, the protruding inner end surface 38 of the movable member 37 is aligned with the concave inner end surface 4 of both constituent walls 41 and 42.
5, 47 on the hub center P side, that is, the spindle insertion hole 1
It stands out within 4.

In such a case, the disk cartridge of the present invention is loaded into the disk drive, and the support shaft 19 is inserted into the support shaft insertion hole 14 of the hub 10 through the peripheral wall portion 31 and the first,
When guided and inserted by the second constituent walls 41 and 42,
First, the protruding inner end surface 38 of the movable member 37 elastically contacts the outer periphery of the support shaft 19 and retracts into the recess 43, and the circumscribed surface of the peripheral wall portion 31 is caused by the elastic force of the cantilever arm 36 that supports the movable member 37. 32, 32 are urged into contact with the circular outer peripheral surface of the support shaft 19, and the movable outer contacts of the movable member 37
The hub 10 is elastically held in an aligned state with respect to the support shaft 19 in a three-point contact state of P ₃ and the two fixed external contacts P ₁ and P ₂ formed by the circumscribed surfaces 32 and 32. At this time, since the cantilever arm 36 has a long cantilever span, the elastic contact force of the fixed external contacts P ₁ and P ₂ with respect to the support shaft 19 is always guaranteed to be constant over a long period of time even if it is used repeatedly.

The contact surface 16a of the engaging portion (rib) 16 that crosses each guide groove 15 on the side that the drive shaft 20 comes into contact with passes through the hub center P and connects to both circumscribed surfaces 32, 32 as shown in FIG.
is formed parallel to a line l perpendicular to the axis of symmetry L, and when the circular outer peripheral surface of the drive shaft 20 is in contact with the contact surface 16a, the central axis of the drive shaft 20 is on the orthogonal line l. The dimensions are set as shown. Therefore, the drive shaft 2 on the disk drive side
Even when the disk 23 is driven to rotate by abutting and engaging with the engaging portion 16, both circumscribed surfaces 32, 32 are further pressed against the outer periphery of the support shaft 19 to prevent track displacement. .

Furthermore, in the state where the upper and lower hub components 12 and 13 are integrally coupled, there is a gap between one side end surface 35 of the peripheral wall portion 31 and the first component wall 41, and between the other side end surface 35 of the peripheral wall portion 31. Second constituent wall 42
slits 48, 4 passing through in the vertical direction between the
8 will be formed. That is, the peripheral wall portion 31 of the lower hub structure 13 and the upper hub structure 12
The spindle insertion hole 14 is constituted by the partial boss 40,
Slits 48, 48 are formed between the peripheral wall portion 31 and the partial boss 40, dividing them in the circumferential direction. Thus, two slits 48, 48 are provided in the inner peripheral surface of the spindle insertion hole 14 in the radial direction, and between the two slits 48, 48, the circumscribed surfaces 32, 32 are aligned with respect to the axis of symmetry L passing through the hub center P. It is formed so that it is symmetrical.
Therefore, the slits 48, 48 are connected to the circumscribed surfaces 32, 32.
The circumferential length of the circumferential wall portion 31 having the above-mentioned circumferential wall portion 31 is suppressed to the necessary minimum to adjust the wall thickness of the circumferential wall portion 31 in the circumferential phase.
The upper and lower hub components 12, 13 are prevented from coming into contact with each other when the and partial bosses 40 are fitted into each other.
It is also intended to make it easier to connect. In addition, the slits 48 contribute to reducing the weight of the hub 10 itself and to stabilizing the weight balance.

Further, on the upper and lower end surfaces of the hub 10, a reference surface 5 for the hub pedestal 17 having a constant width in the circumferential direction is provided on the projecting end surface of the annular projecting outer wall 49 of each guide groove 15.
0 is formed protrudingly at the trisector position, and on the end surface of the inner wall portion 15a constituting the inner wall of each guide groove 15, there is a reference surface 5 for a collect having a constant width in the circumferential direction.
1 is formed protrudingly lower than the reference surface 50 at the trisector position, and one of the upper and lower outer reference surfaces 50
The hub receiving surface 18 of the hub holder 17 is in contact with the hub receiving surface 18, and the tip end surface of the collet 21 is in contact with the other upper and lower inner reference surfaces 51.

The upper and lower end surfaces 37a, 37 of the movable member 37
Move the movable member 3 so that a is vertically inward from the inner reference surface 51 by the protruding height of the reference surface 51.
The upper and lower lengths of 7 are set as dimensions. Therefore, the top end surface of the collet 21 in the figure corresponds to the top end surface 3 of the movable member 37.
Since there is no contact interference with 7a, the movable member 3
7 operates reliably even if there is some variation in the dimensions of each part of the hub 10 due to molding, and reliably guarantees the accuracy of centering the hub 10 with respect to the support shaft 19.

Incidentally, each inner reference surface 51 is located between adjacent outer reference surfaces 50, 50, and the hub holder 17 and the collet 21 clamp and hold the upper and lower end surfaces of the hub 10 in a well-balanced manner. Further, one of the outer reference surfaces 50 is located on the outer side of the peripheral wall portion 31, and
Inner and outer reference planes 50, 5 with respect to the axis of symmetry L of 2, 32
1 are set in a symmetrical arrangement, so when the movable member 37 moves the hub 10 to align it with the support shaft 19, the hub receiving surface 1
The sliding resistance of the outer reference surface 50 with respect to the outer reference surface 8 is made uniform in the sliding direction, so that both the circumscribed surfaces 32, 32 are properly urged into contact with the outer periphery of the support shaft 19. .

In addition, the movable member 37 maintains the alignment of the hub 10 with respect to the spindle 19 even when the disk 2 is not driven, such as when the disk 2 is being driven intermittently, and is effective but essential for preventing track deviation from occurring at the beginning of driving. It doesn't belong to.

The engaging portion 16 formed on the outer periphery of the hub end face is also a recessed hole or a vertical through hole instead of a rib, and the drive shaft 2
The tip of the guide groove 15 may slide into contact with the bottom surface of the guide groove 15 and fit into these recessed holes or through holes. It is also possible to omit this type of engaging portion 16 and drive the hub 10 using a magnetic catch method. However, although the specific structure is not limited, at least when the hub 10 is driven to rotate, both circumscribed surfaces 32, 32
A means for forcibly drawing and abutting the circular outer peripheral surface of the support shaft 19 is necessary.

Further, the spindle insertion hole 14 is formed in an elliptical or polygonal shape in plan view, and a circumscribed surface 32 is formed in a part thereof.
32 may be formed. The circumscribed surface 32 may be formed into a convexly curved surface. Further, the circumscribed surfaces 32, 32 are symmetrical with respect to the axis of symmetry L passing through the hub center P, and the supporting axis 1
The shape of the spindle insertion hole 14 and the circumscribed surface 32 can be freely changed as long as they contact the outer periphery of the spindle 9 at two points P ₁ and P ₂ .

Furthermore, a spindle insertion hole 1 having circumscribed surfaces 32, 32 is provided.
The relief space 33 for adjusting the wall thickness of the peripheral wall portion 31 of No. 4 may be provided at least on the outside of the circumscribed surface 32 in the radial direction and can prevent sink marks from occurring on the circumscribed surface 32 after molding, for example. It may be formed to penetrate in the vertical direction. The slit 48 may be recessed from the upper and lower surfaces of the hub 10 or from one side.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a disk cartridge according to the present invention, and FIG. 2 is a front view of the central longitudinal section thereof. FIGS. 3 to 6 illustrate the lower hub structure of the hub, which is one of the constituent members of the present invention.
4 is a plan view, FIG. 4 is a bottom view, FIG. 5 is a cross-sectional view taken along the line A--A in FIG. 3, and FIG. 6 is a cross-sectional view taken along the line B--B in FIG. 3. 7 to 10 illustrate the upper hub structure of the hub, which is one of the constituent members of the present invention. FIG. 7 is a plan view, FIG. 8 is a bottom view, and FIG. FIG. 10 is a sectional view taken along line C--C in FIG. 7, and FIG. 10 is a sectional view taken along line D--D in FIG. FIG. 11 is a perspective view of the upper and lower hub structures seen from above, and FIG. 12 is a perspective view of the upper and lower hub structures in a state in which they are combined. FIG. 13 is a perspective view of the upper and lower hub assemblies seen from below, and FIG. 14 is a perspective view of the upper and lower hub assemblies in a coupled state. Figure 15 is a plan view of the hub, Figure 16
The figure is a bottom view of the hub, Figure 17 is a sectional view taken along line E-E in Figure 15, and Figure 18 is F in Figure 15.
-F line sectional view. 1...disk case, 2...disk, 3...
...Drive shaft insertion window, 4...Magnetic head insertion window, 9...
... Seat, 10 ... Hub, 12 ... Upper hub structure, 13 ... Lower hub structure, 14 ... Support shaft insertion hole, 15 ... Guide groove, 16 ... Engagement part, 19 ...
... Support shaft, 20 ... Drive shaft, 31 ... Peripheral wall portion of support shaft insertion hole, 32 ... Circumscribed surface, 33 ... Space for relief, 36 ... Cantilever arm, 37 ... Movable member,
40... Partial boss, 41... First component wall, 42...
...Second component wall, 48...slit. _P1 , _P2 ...
Fixed external contact, P ₃ ...Movable external contact.

Claims (1)

[Scope of Claim for Utility Model Registration] A disk 2 is rotatably installed in a disk case 1, and the disk 2 is integrally connected to a disc-shaped seat 9 and the center portion of the seat 9 to form a drive shaft insertion window 3 of the disk case 1. It consists of a plastic hub 10 facing the disk drive side, and a spindle 1 on the disk drive side in the center of the hub 10.
In the disk cartridge having a spindle insertion hole 14 into which the seat 9 is inserted, an upper and lower hub assembly 12 made of plastic is integrally coupled with the hub 10 clamping the peripheral edge of the center hole 8 of the seat 9. 13, the lower hub structure 13 has a hole 29 in the center, and a peripheral wall portion 31 forming a part of the inner periphery of the spindle insertion hole 14 is formed on the inner circumferential surface of the hole 29 in the circumferential direction. Two flat circumscribed surfaces 32, 32 are formed on the inner surface of the peripheral wall portion 31 to make line contact with the circular outer peripheral surface of the support shaft 19 at two points P ₁ and P ₂ . are vertically formed with a predetermined angle θ, and the upper hub structure 12 has a lower hub structure 13
The upper hub structure 12 has a hole 39 in the center thereof into which the peripheral wall portion 31 of the upper hub structure 12 fits.
A partial boss 40 that fits into the cutout hole 29 of the lower hub structure 13 and forms part of the inner circumference of the spindle insertion hole 14
is formed with a predetermined expansion angle in the circumferential direction. When the upper and lower hub members 12 and 13 are joined together, the peripheral wall portion 3 of the lower hub member 13
1 and both circumferential end surfaces of the partial boss 40 of the upper hub structure 12 are formed with slits 48, 48 penetrating in the vertical direction. disk cartridge.