JPH04356782A - Tape cassette - Google Patents

Abstract

PURPOSE:To increase the max. winding diameter of a tape. CONSTITUTION:A tape-like recording medium T is wound around hubs 7 and 8 and housed in a cassette case consisting of upper and lower halves 2 and 3 which are fitted to each other. The hub 7(8) is composed of an inner hub 7b and an outer hub 7a which are engaged with each other in the circumferential direction, constituting 1st and 2nd position regulating means for regulating a moving range of the outer hub 7a and the inner hub 7b independently of each other to the upper and lower half members in the circumferential direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette for storing a tape-shaped recording medium wound around a hub.

0002

[Prior Art] Conventionally, in a tape cassette, a hub for storing a tape-shaped recording medium (magnetic tape) wound inside the cassette housing has a hub drive shaft attached to the inner periphery of the outer hub around which the magnetic tape is wound. Some have an inner hub that transmits the driving force from the inner hub, which is movable in the axial direction and fitted in the inner hub so that it is engaged in the circumferential direction. The prior art of this hub mechanism is shown, for example, in a partial sectional view of a tape cassette in FIG. 9 and a plan view of a hub in FIG. 10. Note that FIG. 9 corresponds to a state in which the hub is viewed in the XX direction of FIG. 10.

As shown in the figure, the hub 73 housed in the upper and lower halves 71 and 72 is composed of an outer hub 74 and an inner hub 75, and the magnetic tape T is attached to the outer peripheral surface 7 of the outer hub 74.
4a, and the inner circumferential surface 75b of the inner hub 75 engages with the hub drive shaft of the recording/reproducing device when the hub drive shaft of the recording/reproducing device is inserted through the insertion holes 71a, 72a of the upper and lower halves 71, 72. A matching protrusion 75c is formed.

[0004] The outer hub 74 is drum-shaped and has an inner peripheral surface 74.
A cylindrical inner hub 75 is fitted into b so as to be slidable in the axial direction and engaged in the circumferential direction.
Engagement convex portions 75 are provided at predetermined intervals in the circumferential direction on the outer peripheral surface 75a of the
d is formed, and an engagement recess 74c is formed on the inner peripheral surface 74b of the outer hub 74 so as to have an engagement action only in the circumferential direction, corresponding to the engagement protrusion 75d. The positions of the outer hub 74 and the inner hub 75 in the circumferential direction are fixed to each other by engagement between the protrusion 75d and the engagement recess 74c. Therefore, when the tape cassette is loaded into the recording/reproducing apparatus, the rotational driving force from the hub drive shaft engaged with the protrusion 75c of the inner hub 75 is transmitted to the outer hub 74 around which the magnetic tape T is wound. Note that the inner peripheral surface 74b of the outer hub 74 and the outer peripheral surface 75a of the inner hub 75 are loosely fitted so that a certain amount of clearance C1 is obtained in the entire circumferential direction. That is, the diameter of the inner circumferential surface 74b is smaller than the diameter of the outer circumferential surface 75a by (2×C1).

As described above, since the hub 73 is formed by the outer hub 74 and the inner hub 75 that are loosely fitted, the inner hub can be rotated from outside the cassette case by using a finger or a pencil. Even if the magnetic tape T 75 is tilted or shakes in the axial direction, the effect will not be transmitted to the outer hub 74, and therefore the magnetic tape T wound around the outer hub 74 will not be affected.
This will prevent inconveniences such as swinging or damage due to contact with the inner surface of the half.

Further, as is clear from FIG. 9, the position of the hub 73 is restricted by forming a locked surface 75e, which is a part of the outer peripheral surface 75a of the inner hub 75, into a circular recess on the inner surface of the upper and lower halves 71 and 72. The locking portions 71b and 72 formed as the peripheral surface of the
This is done by making contact with b. Then, the hub drive shaft, insertion holes 71a, 72a, and hub 73 of the recording/reproducing device.
For the purpose of absorbing positional errors between
Therefore, the hub 73 is supported within the upper and lower halves 71 and 72 in a loosely fitted manner. In other words, the locking parts 71b, 72b
The diameter of the circular depression in which the inner hub 75 is formed is set to be (2×C2) larger than the diameter of the outer peripheral surface 75a of the inner hub 75.

[0007]

[Problems to be Solved by the Invention] In such a hub mechanism, the position of the hub 73 is regulated to have a clearance C2, and the outer hub 74 and the inner hub 75 are loosely fitted with a clearance C1. As mentioned above, both of these clearances are important for protecting the magnetic tape T and absorbing positional errors of each mechanism, but on the other hand, the cumulative amount of movement of the hub 73 in the circumferential direction is the amount of movement of the hub 73. This results in a problem in that the winding diameter of the magnetic tape T is limited.

That is, as shown in FIG.
In order to prevent the outermost magnetic surface of the magnetic tape T from coming into contact with the wall surface 80 forming the storage area for the magnetic tape T in the tape cassette half when the magnetic tape T reaches its maximum winding diameter, Wall surface 80 from the outermost circumference of the magnetic tape T
At least C1 + C2 in the entire circumferential direction
A dimensional margin for the above amount is required, that is, the maximum winding diameter DTm1 of the magnetic tape T must be smaller than the diameter DA1 of the smallest portion of the storage area by 2×(C1 +C2). This restriction on the maximum winding diameter has a large effect on the tape length of the magnetic tape T being wound, which is inconvenient when it is desired to extend the recordable time. .

[0009]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and includes a tape-shaped recording medium wrapped around a hub and stored in a cassette housing formed by fitting upper and lower half members. In such a tape cassette, the hub is formed by an inner hub and an outer hub that engage in the circumferential direction, and the outer hub and inner hub independently regulate the movement range with respect to the upper and lower halves. The purpose is to ensure that That is, the locked portion provided on the outer hub and the first locking portion formed on the upper and lower half members constitute a first position regulating means for regulating the movement range of the outer hub in the circumferential direction. The locked portion provided on the hub and the second locking portion formed on the upper and lower half members constitute a second position regulating means for regulating the movement range of the inner hub in the circumferential direction.

0010

[Operation] Since the outer hub and the inner hub are each provided with a position regulating means for regulating the movement range in the circumferential direction, the movement range of the outer hub is influenced by the clearance between the fitting part of the outer hub and the inner hub. It is set only by the clearance in the first position regulating means for the outer hub. Therefore, the maximum winding diameter of the magnetic tape relative to the diameter of the minimum portion of the magnetic tape storage area may be set by taking only the clearance in the first position regulating means into consideration. Further, the movement range of the inner hub in the circumferential direction is restricted only by the second position regulating means and is affected only by the clearance of the second position regulating means, and is not affected by the clearance of other components. The movement range does not change.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tape cassette of the present invention will be described below with reference to FIGS. 1 to 6. Note that the tape cassette of this example is configured to be extremely small. 3 to 6, reference numeral 1 generally indicates a tape cassette that stores a magnetic tape for recording and reproducing PCM signals, and the housing of this tape cassette 1 has an upper half 2 and a lower half 3 facing each other, The two halves 2 and 3 are assembled together by being tightened, and a lid 6 that opens and closes an opening 5 formed on the front side of both halves 2 and 3 is rotatably supported.

Inside this cassette housing, that is, the upper and lower halves 2,
3, as shown in FIG. 5, there is an insertion hole 2a for the hub drive shaft.
, 2b and 3a, a pair of hubs 7 arranged corresponding to 3b.
, 8, and a portion of the magnetic tape T has pinch rollers 9, 10 which also serve as guide rollers and are rotatably supported on both sides of the front opening 5. It is made to be exposed to the front opening 5 in a stretched state through the opening 5.

[0013] Also, inside this cassette housing, both hubs 7,
8 is provided with a brake mechanism 11 that operates the brake when not in use, and furthermore, on the upper and lower surfaces of the cassette housing, upper and lower half halves 2 and 3 are located at each part on both sides of the rear part.
In addition, positioning reference holes 14, 15 and 16, 17 are provided at both sides in the front and rear direction of the center and in the rear lateral direction. A plurality of required detection holes 18 and 19 are formed in the direction, and grip portions 20 and 21 are further formed at the rear of both sides. In addition, the front side opening 5 of the cassette housing
The lid 6 for opening and closing is provided with a changer engaging portion 23 along a lateral guide groove 22.

In the tape cassette 1 constructed as described above, the magnetic tape T stored in the cassette housing is recorded and reproduced using a helical scan method using a rotary head. That is, as shown in FIG. 4, the rotary head 41 is rotated at a predetermined angle with respect to the head drum 42, and the head drum 42 rotates the lid 6 of the cassette housing upward or downward. The magnetic tape T, which is partially inserted into the front side opening 5 opened by the above operation and stretched across this opening 5, slides so as to wrap around the insertion side circumferential surface of the head drum 42. When the rotary head 41 rotates, an inclined track that diagonally crosses the magnetic tape T is formed.

At this time, the magnetic tape T is attached to the head drum 42.
In this embodiment, a pair of tape guides whose guide members are inclined in opposite directions is provided at the insertion portion of the head drum 42 in the opening 5 of the cassette housing so that the tape guides are in helical sliding contact with each other. The members 24 and 25 are connected to the guide roller 9
, 10, and are arranged so as to be able to swing and move laterally, facing each other. Therefore, by inserting the head drum 42 into the opening 5 as shown in FIG. 6, the tape guide members 24 and 25 come into contact with the circumferential surface of the head drum 42. The magnetic tape T is guided with it sandwiched between them.

Pinch rollers 9 are provided on both sides of the head drum 42 on both sides of the opening 5 of the cassette housing.
, 10 and tape guide members 24, 25 are provided, and rollers 43a, 4 are provided at the front ends of the wing guides 43, 44.
4a is attached, and the magnetic tape T is guided through the tape guide member 24.
, 25. These wing guides 43, 44 include support pieces 26, 27 from the inside of the opening 5 of the cassette housing, and guides for preventing tape extrusion located between the support pieces 26, 27 and the pinch rollers 9, 10. It is designed to be inserted between the protrusions 28 and 29.

In the tape cassette 1 constructed as described above, FIG. 1 shows the hubs 7 and 8 rotatably supported with the magnetic tape T wound inside the cassette housing.
, will be explained in detail with reference to FIG. In addition, both hubs 7 and 8
Since the two hubs have the same configuration, only the mechanism of one hub 7 will be illustrated and explained, and the illustration and explanation of the other hub 8 will be omitted. FIG. 1 is a partial sectional view of a tape cassette for explaining the mechanism of the hub 7, and FIG.
FIG. Note that FIG. 1 corresponds to the state where the hub 7 is viewed in the Y-Y direction in FIG. 2, and in FIG. The position is indicated by a dashed line.

As shown in the figure, the hub 7 housed in the upper and lower halves 2 and 3 is composed of an outer hub 7a and an inner hub 7b, and the magnetic tape T is attached to the outer peripheral surface 7a1 of the outer hub 7a.
Also, on the inner circumferential surface 7b2 of the inner hub 7b,
A protrusion 7b3 is formed which engages with the hub drive shaft of a recording/reproducing device when the hub drive shaft of the recording/reproducing device is inserted through the insertion holes 2a, 3a of the upper and lower halves 2, 3.

A cylindrical inner hub 7b is fitted into the inner peripheral surface 7a2 of the drum-shaped outer hub 7a so as to be slidable in the axial direction and engaged in the circumferential direction. That is,
Engagement protrusions 7b4 are formed on the outer peripheral surface 7b1 of the inner hub 7b at predetermined intervals in the circumferential direction, and engagement recesses 7a3 are formed on the inner peripheral surface 7a2 of the outer hub 7a.
Corresponding to b4, an engaging action is obtained only in the circumferential direction. Due to the engagement between the engagement protrusion 7b4 and the engagement recess 7a3, the positions of the outer hub 7a and the inner hub 7b in the circumferential direction are fixed to each other. The rotational driving force from the hub drive shaft that engages with the portion 7b3 is transmitted to the outer hub 7a around which the magnetic tape T is wound. Note that the inner peripheral surface 7a2 of the outer hub 7a
and the outer circumferential surface 7b1 of the inner hub 7b are loosely fitted so that a certain amount of clearance C3 is obtained in the entire circumferential direction. In this way, the outer hub 7a and the inner hub 7b
is in a loosely fitted state, from the insertion holes 2a and 3a,
When the hub drive shaft, finger, pencil, etc. are inserted, the inner hub 7
Even if b tilts or wobbles in the axial direction, the effect will not be transmitted to the outer hub 7a, and therefore the magnetic tape T wound around the outer hub 7a will swing or come into contact with the inner surface of the half and be damaged. There are no inconveniences such as getting stuck.

[0020] In this way, the outer hub 7a and the inner hub 7
The position regulating means for regulating the movable range within the half of the hub 7 constituted by the hub 7 is provided for the outer hub 7a and the inner hub 7b, respectively. First, the position regulating means for the outer hub 7a is arranged so that the outer hub 7a has a locked surface 7a4.
is formed toward the outer circumferential surface 7a1, and a locking portion 2c1 is formed as the outer circumferential surface of the ring-shaped recessed portions 2c, 3c provided on the inner surfaces of the upper and lower halves 2, 3.
, 3c1 are formed, that is, the sliding position in the circumferential direction is regulated by the locked surface 7a4 of the outer hub 7a coming into contact with the locking parts 2c1, 3c1 of the upper and lower halves 2, 3. There is. Further, the position regulating means for the inner hub 7b includes a locked surface 7b5 formed on the inner hub 7b toward the inner circumferential surface 7b2 of the inner hub 7b, and a ring-shaped recess in the upper and lower halves 2 and 3. Part 2
The locking portions 2c2 and 3c2 are the inner peripheral surfaces of c and 3c.
This is realized by forming the locking surface 7a5 of the inner hub 7b into the locking portion 2c2 of the upper and lower halves 2, 3.
, 3c2, the sliding position in the circumferential direction is restricted.

The diameter of the locked surface 7a4 of the outer hub 7a is set such that the locked surface 7a4 of the outer hub 7a is supported in a loosely fitted state with a clearance C4 to the locking portions 2c1 and 3c1 in the entire circumferential direction. , locking portions 2c1, 3c1
It is set to be smaller by (2×C4) than the outer diameter of the ring-shaped recesses 2c and 3c in which the ring-shaped recesses 2c and 3c are formed. Further, the diameter of the locked surface 7b5 of the inner hub 7b is set such that the locked surface 7b5 of the inner hub 7b is supported in a loosely fitted state with a clearance C5 to the locking portions 2c2 and 3c2 in the entire circumferential direction. Part 2c2, 3c2
is set to be (2×C5) larger than the inner diameter of the ring-shaped recesses 2c, 3c in which the grooves are formed, and the connection between the hub drive shaft of the recording/reproducing device, the insertion holes 2a, 3a, and the hub 7 is Positional errors etc. are absorbed by this clearance C5.

As described above, in this embodiment, the position of the outer hub 7a in the circumferential direction is independently regulated by the engagement of the locked surface 7a4 with the locking portions 2c1 and 3c1. The movable range of is clearance C4
The clearance C3 between the outer hub 7a and the inner hub 7b is not accumulated in the amount of movement of the entire hub 7. Therefore, in the tape cassette of this embodiment,
The maximum winding diameter DTm2 of the magnetic tape T shown in FIG. 5 may be set smaller by at least (2×C4) than the diameter DA2 of the minimum part of the magnetic tape storage area inside the half.
The clearance C3 between the outer hub 7a and the inner hub 7b (
The winding diameter of the magnetic tape T can be increased by an amount that does not require consideration of C1) in the conventional example shown in FIG. 9, and the recording time can be easily extended.

Furthermore, in this embodiment, the position of the inner hub 7b in the circumferential direction is independently controlled by the engagement of the locked surface 7b5 with the locking portions 2c2 and 3c2, so that the movement of the inner hub 7b is restricted. The possible range depends only on the clearance C5, and other clearances are not accumulated in the amount of movement of the inner hub 7b. Therefore, inner hub 7
There is no misalignment of the hub drive shaft b, and the hub drive shaft is always smoothly introduced into the inner hub 7b.

00
24] FIG. 7 is a partial sectional view of a tape cassette for explaining the mechanism of the hub 7 as another embodiment of the present invention.
FIG. 8 is a plan view of the hub 7 of this embodiment. 7 corresponds to the state in which the hub 7 is viewed in the Z-Z direction in FIG. 8, and in FIG.
The corresponding positions of d1, 2d2, and 3d2 are indicated by dashed dotted lines. In these figures, the same functional parts as in FIGS. 1 and 2 are indicated by the same reference numerals.

In this embodiment, the outer hub 7a and the inner hub 7b are engaged in the circumferential direction by the engagement recess 7a3 and the engagement protrusion 7b4, so that the outer hub 7a and the inner hub 7b are engaged in the circumferential direction. Their positions are mutually fixed, and when loaded into a recording/reproducing device, the rotational driving force from the hub drive shaft that engages with the protrusion 7b3 of the inner hub 7b is applied to the outer hub around which the magnetic tape T is wound around the outer peripheral surface 7a1. The transmission to the outer hub 7a is the same as in the above-described embodiment, but the first position regulating means for regulating the movable range within the half of the outer hub 7a is directed toward the inner circumferential surface 7a2 of the outer hub 7a. At the same time, ring-shaped protrusions 2d, 3d are formed on the inner surfaces of the upper and lower halves 2, 3, and locking parts 2d1, 3d are formed as the outer peripheral surfaces of the protrusions 2d, 3d.
1 is formed, and the locked surface 7
The range of movement of the outer hub 7a in the circumferential direction is regulated by a clearance C4 between a4 and the locking portions 2d1 and 3d1. In addition, as a second position regulating means for regulating the movable range within the half of the inner hub 7b, a locked surface 7b5 toward the outer circumferential surface 7b1 of the inner hub 7b is used.
is formed, and a locking portion 2d2 is formed as the inner peripheral surface of the projections 2d, 3d on the inner rings of the upper and lower halves 2, 3.
, 3d2 are formed, and the movement range of the inner hub 7b in the circumferential direction is regulated by a clearance C5 between the locked surface 7b5 and the locking portions 2d2 and 3d2. Also in this embodiment in which the locked surface 7a4 is formed on the inner peripheral surface side of the outer hub 7a, the same effects as in the embodiment shown in FIG. 1 can be obtained.

By the way, in each of the above embodiments, the structure of the hub 8 and the structure of the insertion holes 2b, 3b including the locking portions are the same as those of the hub 7, the insertion holes 2a, 3a, and the locking portion 2c, respectively.
1 , 3c1 , 2c2 , 3c2 (2d1 , 3d
1, 2d2, 3d2).

The mechanism of the hubs 7 and 8 of the tape cassette according to the present invention is not limited to the above-mentioned embodiments, and at least the outer hub 7a and the inner hub 7b each have their own locking surfaces that are located above and below. 1st and 2nd of half 2 and 3
Any mechanism or shape may be used as long as it engages with each of the locking portions to restrict the movement range of the upper and lower halves 2 and 3, respectively.

[0028]

[Effects of the Invention] As explained above, in the tape cassette of the present invention, the outer hub and the inner hub each have their own position regulating means for the upper and lower half members, so that the movement range in the circumferential direction is independently regulated. As a result, the movable range of the outer hub does not change due to the clearance between the engaging portion of the outer hub and the inner hub, and the maximum winding diameter of the magnetic tape can be set larger than before, resulting in longer recording times. This has the effect that it can be easily realized. Furthermore, the movement range of the inner hub in the circumferential direction is affected only by the clearance of the position regulating means for the inner hub, and the movement range does not change due to the influence of the clearance of other components. There is no possibility that the inner hub will be misaligned, and therefore the hub drive shaft can always be smoothly introduced into the inner hub.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a hub mechanism of a tape cassette according to an embodiment of the present invention.

FIG. 2 is a plan view of the hub of this embodiment.

FIG. 3 is a perspective view of the tape cassette of this embodiment.

FIG. 4 is a perspective view showing the relationship between the tape cassette and head drum of this embodiment.

FIG. 5 is a plan view of the lower half side of the tape cassette of this embodiment.

FIG. 6 is a plan view of a state in which a head drum is inserted into the tape cassette of this embodiment.

FIG. 7 is a sectional view showing a hub mechanism of a tape cassette according to another embodiment of the present invention.

FIG. 8 is a plan view of a hub of another embodiment.

FIG. 9 is a sectional view showing a hub mechanism of a conventional tape cassette.

FIG. 10 is a plan view of a conventional hub.

FIG. 11 is an explanatory diagram of the magnetic tape winding diameter of a conventional tape cassette.

[Explanation of symbols]

2 Upper half 3 Lower half 2a, 3a, 2b, 3b insertion hole 2c, 3c hollow part 2c1, 3c1 Locking part 2c2, 3c2 Locking part 2d, 3d protrusion 2d1, 3d1 Locking part 2d2, 3d2 Locking part 7, 8 Hub 7a Outer hub 7a1 Outer surface 7a2 Inner peripheral surface 7a3 Engagement recess 7a4 Locked surface 7b inner hub 7b1 Outer peripheral surface 7b2 Inner peripheral surface 7b3 Protrusion 7b4 Engagement protrusion 7b5 Locked surface

Claims (1)

[Claims] 1. A tape cassette in which a tape-shaped recording medium is wound around a hub and stored in a cassette housing formed by fitting upper and lower half members, wherein the hub has an inner hub and an outer hub arranged in a circumferential direction. a first position restriction that engages with the outer hub and restricts a circumferential movement range of the outer hub by a locked portion provided on the outer hub and a first locking portion formed on the upper and lower half members; a second position regulation means, the second position regulation means being configured, and regulating a movement range of the inner hub in the circumferential direction by a locked part provided on the inner hub and a second locking part formed on the upper and lower half members; A tape cassette comprising means.