JP2000048525A - Magnetic tape cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of folding of tape due to elongation and looseness of a tape due to the tension by maintaining the tension of the magnetic tape to the optimum condition under the condition that the rotation of reel controlled by a reel rotation controlling means. SOLUTION: In a reel rotation controlling means comprising a controlling member 4 which is in contact or in separation from a reel for restricting rotation of reel through engagement between a control gear and an engagement projection, an energizing member for energizing the control member 4 in the controlling direction and a canceling member which moves in response to the chucking operation of a drive side rotation driving means for moving the control member 4 in the canceling direction, the control member 4 is restricted not to rotate due to the rotation stop structure against the cartridge case, the allowable rotating angle θ resulting from size difference in the rotation stop structure is set to 1/2 or larger than the one pitch angle α of the control gear, and the sum angle of the allowable rotation angle θ and a half of the one pitch angle a is set to 7 deg. or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cartridge, and more particularly, to a magnetic tape cartridge in which a single reel having a magnetic tape wound in a cartridge case is rotatably accommodated, and the reel is not used. The present invention relates to a structure of a reel rotation stopping means that is sometimes set to a rotation stopped state.

[0002]

2. Description of the Related Art Conventionally, a magnetic tape cartridge used as a recording medium used for an external storage device such as a computer has a magnetic tape wound around a single reel.
A type in which this reel is rotatably housed in a cartridge case is known. Since this magnetic tape is used for data storage in computers and the like and stores important information, the magnetic tape should be pulled out carelessly so that troubles such as tape jamming do not occur and when not in use such as storage. To prevent the reel from rotating, a reel rotation stopping means for restricting the rotation of the reel is provided.

The reel rotation stopping means includes a stopping member which engages with a part of the reel and restrains the rotation of the reel, and when the cartridge is loaded into a drive such as an external storage device,
The stopping member is provided so as to release the stopped state in accordance with the reel chucking operation by the drive-side rotation driving means.

[0004]

However, in the state where the reel rotation is restrained by the above-mentioned reel rotation stopping means,
If excessive tension is applied to the magnetic tape, the magnetic tape will be further loaded due to temperature changes, vibration, etc.
Due to problems such as elongation of the magnetic tape,
It is necessary to restrain the rotation with the tension relaxed. On the other hand, if the magnetic tape is largely loosened while the rotation of the reel is restrained, the magnetic tape may be loosened and bend.

By the way, a substantially cylindrical pull-out member (leader pin or the like) is provided at the end of the magnetic tape wound on the reel.
The drive device is configured such that the drawer member is drawn out of the cartridge case through the opening toward the recording / reproducing device side to take up or rewind the magnetic tape. When the use of the magnetic tape is finished and the magnetic tape is rewound, the drawer member at the end of the magnetic tape is pulled into the cartridge case and locked, and in this state, when the drive of the reel is stopped and the reel is released. A part of the reel is engaged with the stopping member by the reel rotation stopping means to restrict the rotation. The rotation of the restraining member is regulated by a rotation preventing structure with respect to the cartridge case. The rotation preventing structure has a clearance due to a dimensional difference in manufacturing, and the reel in the restricted state rotates by the clearance.

However, when the rotation of the reel is restrained by the stopping member, the stopping gear and the locking projection are engaged with each other in the stopped state of the rewinding rotation of the reel. The phase of the reel is shifted between the angles, and this phase change changes the tension state of the magnetic tape, and when an excessive tension load acts on the magnetic tape, it causes the above-described elongation and the like, and causes an excessive amount of tension. The occurrence of loosening causes the above-mentioned breakage and the like.

If the clearance in the rotation direction of the above-mentioned stopping member with respect to the case is small, it may hinder the formability and assembly of the case and the stopping member, and if the pitch angle of the stopping gear is reduced, it is difficult to restrict the rotation of the reel. Become.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a magnetic tape cartridge in which the tension of a magnetic tape can be maintained in an optimum state in a rotation-restricted state of a reel by a reel rotation stopping means. .

[0009]

According to the magnetic tape cartridge of the present invention which solves the above-mentioned problems, a single reel having a magnetic tape having a substantially cylindrical drawer member wound at the end thereof can be rotated in a cartridge case. The reel rotation stop means for allowing rotation of the reel when in use and restricting the rotation of the reel when not in use, the reel rotation stop means being capable of coming and going with respect to the reel. A stopping member that moves to restrain the rotation of the reel by engagement of the stopping gear and the locking protrusion, a biasing member that biases the stopping member in the stopping direction, and a drive-side rotational drive that rotates integrally with the reel. A release member that moves in accordance with the chucking operation of the means and moves the stop member in the release direction, wherein the stop member has a detent structure between the cartridge case and the cartridge case. The allowable rotation angle due to the dimensional difference in the rotation preventing structure is set to not less than の of one pitch angle of the stopping gear, and the allowable rotation angle and one pitch angle of the stopping gear are restricted. Is set to 7 ° or less.

[0010]

According to the present invention as described above, the permissible rotation angle due to the dimensional difference in the rotation preventing structure between the stopping member of the reel rotation stopping means and the cartridge case is set to one pitch angle of one pitch of the stopping gear. When the reel is rewinded and rotated to the final rewind state by releasing the reel and the reel is released and the reel is released, the stopping gear and the locking projection mesh with the locking projection to disable the rotation of the reel. Even if the reel rotates in the direction in which the magnetic tape is pulled due to a phase shift between the two in this meshing, the reel is rotated by the rotation of the stopping member relative to the case within the allowable rotation angle of the rotation preventing structure. The tape is loosened, temperature changes,
Even if a load acts on the magnetic tape due to vibration or the like, the occurrence of tape elongation can be prevented. Also, by setting the total angle of the allowable rotation angle and 1/2 of one pitch angle of the stopping gear to 7 ° or less, the reel is loosened due to a phase shift at the time of engagement of the stopping gear and the locking projection. Even if the stop member rotates in the loosest direction at the allowable rotation angle, the slack in the magnetic tape does not cause tape breakage, preventing the magnetic tape from deteriorating in the storage state. And good performance can be maintained, and moldability and assemblability can be secured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is a cross-sectional view of the magnetic tape cartridge according to the embodiment in a non-use state, FIG. 2 is an exploded perspective view of a main part, and FIG. 3 is a cross-sectional view of the main part in a use state.

The magnetic tape cartridge 1 has a single reel 2 on which a magnetic tape (not shown) is wound, and an upper case 31.
And a lower case 32 provided with an opening 32a at the center thereof, and a lower case 32 fastened by screws or the like in a cartridge case 3;
The reel 2 is rotatably accommodated. Further, the magnetic tape cartridge 1 includes a reel rotation stopping means 10 for permitting the rotation of the reel 2 when in use and restricting the rotation of the reel 2 when not in use.

A substantially cylindrical drawer (not shown) for pulling out the magnetic tape is fixed to the end of the magnetic tape, and both ends of the drawer projecting from the magnetic tape are attached to the cartridge case 3. Is fixedly held by a lock member in a removable manner in the opening.

The reel 2 has a bottomed cylindrical reel hub 21 around which a magnetic tape is wound around an outer periphery, and a lower flange portion 22 and an upper flange which protrude radially from the outer periphery of the upper and lower ends of the reel hub 21, respectively. The reel hub 21 and the lower flange 22 are integrally formed of a synthetic resin, and are connected to the upper flange 23 by, for example, ultrasonic welding. The lower portion of the reel hub 21 is closed at the center by a bottom wall 21a, and a reel gear 24 for rotating the reel 2 is engraved in an annular shape on an outer peripheral portion of a lower surface of the bottom wall 21a. Plate 25 made of annular metal plate for vacuum suction
Is attached. The reel gear 24 and the reel plate 25 of the reel 2 are arranged so as to face the opening 32 a on the bottom surface of the cartridge case 3. In addition,
The reel 2 is urged downward by an urging member 5 described later.

The drive-side rotary drive means 11 has an annular drive gear 13 and a magnet (not shown) on the upper end surface of the rotary shaft 12, and its chucking operation is performed by loading the drive-side bucket (not shown). The driven magnetic tape cartridge 1 descends with respect to the rotating shaft 12, and the driving gear 13 meshes with the reel gear 24, and the magnet plate attracts the reel plate 25 to maintain the meshing state.

Next, the mechanism of the reel rotation stopping means 10 will be described. The reel rotation restraining means 10 includes a restraining member 4 which moves up and down so as to be able to contact and separate from the reel 2.
A biasing member 5 for biasing the restraining member 4 in a restraining direction;
A release member 6 for moving the stop member 4 in the release direction.

The bottom wall 21a of the reel 2 has three insertion holes 2 penetrating vertically through the reel gear 24.
6 are arranged at regular intervals on the circumference, and three sets of six locking projections 27 are provided on the upper surface of the bottom wall 21a at a different phase position from the insertion hole 26 at regular intervals on the circumference. The tip of the locking projection 27 is formed in a gear tooth shape. In addition,
The insertion hole 26 and the locking projection 27 may be arranged in three or three or more sets, and the tip of the locking projection 27 may have a single gear tooth shape. The reel 2 shown in FIG.
Is shown in a state where only the portion is cut off.

The stopping member 4 has a disk portion 41 disposed inside the reel hub 21 of the reel 2 so as to face the bottom wall 21a. An annular stopping gear 42 is provided on the outer peripheral portion of the lower surface of the disk portion 41. The stop gear 42 can be engaged with the tip of the locking projection 27. The center of the lower surface of the disk portion 41 is formed so as to project in a convex shape, and comes into contact with the center of the upper surface of a plate-shaped base 61 of the release member 6 described later.

Further, a protrusion 44 is formed on the upper surface of the disk portion 41 of the restraining member 4 so as to extend upward. The protrusion 44 is provided with a cross-shaped locking groove 45 extending vertically. . On the other hand, the upper case 3 of the cartridge case 3
A cross-shaped rotation preventing projection 33 to be inserted into the locking groove 45 is provided upright on the inner surface of 1 (see FIG. 5). In addition, the engagement between the locking groove 45 and the rotation preventing protrusion 33 enables the stopping member 4 to be vertically movable without rotating. The locking groove 45 and the rotation preventing protrusion 33 may be provided in a single character.

A biasing member 5 formed by a coil spring is provided between the upper surface of the disk portion 41 on the outer peripheral side of the projection 44 of the stopping member 4 and the inner peripheral surface of the rotation preventing projection 33 of the upper case 31.
Is pressed to urge the stopping member 4 downward in the stopping direction in which the stopping gear 42 and the locking projection 27 are engaged.

The release member 6 is provided with the stopping member 4.
And a bottom wall 21a of the reel hub 21 are vertically movably interposed, and a column-shaped push-up portion 63 is provided on the lower surface near each vertex of the substantially triangular plate-like base portion 61 and extends vertically. . Each push-up portion 63 is provided on the bottom wall 2 of the reel 2.
1a is inserted so as to be able to move in and out of an insertion hole 26, and its tip is located facing the tooth portion of the reel gear 24 on the lower surface of the reel 2. At this time, the locking projection 27 is located outside the plate-like base 61 between the push-up portions 63. Note that the push-up portion 63 may be formed in a rectangular column shape, an elliptical column shape, or the like.

When the release member 6 is at the lowest position (FIG. 1), the lower end surface of the push-up portion 63 is located substantially at the tooth tip of the reel gear 24, and the drive gear is driven by the chucking operation of the drive rotation driving means 11 on the reel gear 24. The release member 6 is pressed in accordance with the engagement of the members 13 and is pushed up by a predetermined stroke amount (FIG. 3). The release member 6 rotates integrally with the reel 2 by fitting the push-up portion 63 into the insertion hole 26. The stopping member 4 is urged by the urging member 5 such that the tip of the convex portion at the center of the lower surface thereof comes into contact with the upper surface of the release member 6. Make sliding contact.

Further, the reel 2 is provided with a guide member 28 for guiding a part of the release member 6 in the insertion direction when the push-up portion 63 of the release member 6 is inserted into the insertion hole 26. 4). The guide member 28 is provided on the inner wall of the reel hub 21 of the reel 2 in the vicinity of the insertion hole 26 so as to guide both corners of each top of the substantially triangular plate-shaped base 61 of the release member 6 (a push-up portion 63). (In the direction of insertion).

FIG. 4 is a plan view of FIG. 3 cut between the upper surface of the release member 6 and the lower surface of the restraining member 4. The one pitch angle α at the engagement of the leading teeth of the locking projections 27 of the reel 2 with the stopping gear 42 is formed at 3 °. That is, the number of teeth of the stopping gear 42 of the stopping member 4 is one.
At 20, when the engagement between the stopping gear 42 and the locking projection 27 is disengaged by one tooth (one pitch), the rotation phase of the reel 2 is shifted by 3 ° with respect to the stopping member 4.

The stopping gear 42 and the locking projection 27
When the gear teeth of both gears are isosceles and the phases of the two gears at the start of meshing are shifted from the phase of the final meshing state, the reel 2 moves in the plus direction or It will be shifted at most 1 / 2α in the minus direction. The one pitch angle α is appropriately changed in design according to the number of teeth of the stopping gear 42.

FIG. 5 is a plan view of the upper case 31 at the position of the detent 33 above the restraining member 4 in FIG. A dimensional difference between the groove width of the locking groove 45 and the thickness of the rotation preventing projection 45 in the rotation preventing structure in which the locking groove 45 of the projection 44 and the rotation preventing projection 33 of the upper case 31 in the stopping member 4 are engaged. Accordingly, the stop member 4 is provided so as to be rotatable by an allowable rotation angle θ with respect to the cartridge case 3 by a clearance between the two.

That is, the permissible rotation angle θ is equivalent to the play during the so-called rotation constraint, and one side of the locking groove 45 and one side of the rotation preventing projection 33 come into contact with each other when the restraining member 4 rotates. This is the rotation angle from the position where the other side of the locking groove 45 is brought into contact with the other side of the rotation preventing projection 33.

The permissible rotation angle θ is set to be equal to or more than の of one pitch angle α of the stopping gear 42, and is one of the permissible rotation angle θ and one pitch angle α of the stopping gear 42. / 2 is 7 ° or less, that is,
0.5α ≦ θ ≦ 7−0.5α is set. In the above example, since one pitch angle α is 3 °, the allowable rotation angle θ is set in a range from 1.5 ° to 5.5 °.
The rotation angle of 7 ° of the reel 2 corresponds to a slack amount (length) of the magnetic tape wound to the maximum diameter of about 6 mm, and is set so that slack exceeding the slack amount does not occur. ing.

The operation of the reel rotation stopping means 10 will be described. FIG. 1 shows a state in which the magnetic tape cartridge 1 is not used, for example, in a storage state. In this state, the urging force of the urging member 5 causes the stopping member 4, The release member 6 and the reel 2 have moved to the lower case 32 side of the cartridge case 3, and the opening 32 a at the center of the lower case 32 is closed by the reel 2. The release member 6 has a lower surface formed on the bottom wall 21 of the reel hub 21.
a is in the lowermost state in contact with the upper surface, and its push-up portion 63 projects so that the front end thereof coincides with the tooth tip position of the reel gear 24, and the stopping member 4 in contact with the upper surface of the release member 6 also moves down. In this position, the leading end of the locking projection 27 of the reel 2 is engaged with the stopping gear 42 so that the rotation of the reel 2 when not in use is restrained, thereby preventing the magnetic tape from being pulled out.

On the other hand, when the cartridge shown in FIG. 3 in which the magnetic tape cartridge 1 is loaded in the drive is used, the rotating shaft 12 of the drive-side rotating drive means 11 approaches the bottom surface of the reel 2 and the driving gear 1 is moved by the chucking operation.
When the gear 3 meshes with the reel gear 24 and moves the reel 2 slightly upward and holds it, the tooth tip of the drive gear 13 comes into contact with the tip of the push-up portion 63 of the release member 6 to push it up. Along with this, the release member 6 moves upward against the urging force of the urging member 5, and the stopping member 4 moves integrally with the release member 6 in the upward release direction. As a result, the engagement between the stopping gear 42 and the locking projection 27 is released, and the reel 2 becomes rotatable. Then, the magnetic tape is pulled out or wound up by the drive of the recording / reproducing apparatus.

Then, the reel 2 is rewound and rotated by the drive-side rotation drive means 11 from the state where the magnetic tape is being unwound from the reel 2, and the pull-out member at the leading end of the magnetic tape is engaged with the magnetic tape cartridge 3 and magnetically. When the leading end of the tape is fixed to a final rewind state, the drive is stopped, the magnetic tape cartridge 1 is moved upward to release the reel 2, and the reel 2 descends and is relatively moved with respect to the reel 2. The release member 6 and the stopping member 4 are lowered by the urging means 5, and the leading end of the locking projection 27 of the reel 2 meshes with the stopping gear 42 of the stopping member 4, thereby restricting the rotation of the reel 2 as described above. You. At this time, with the rewind rotation of the reel 2 and the release member 6, the stop member 4 also rotates in the rotation direction and is at one end (the end on the tightening side of the magnetic tape) of the allowable rotation angle θ.

In the engagement between the stopping gear 42 and the locking projection 27, the phase of the two at the start of the engagement is shifted from the phase of the final engagement state, and the reel 2 is moved in the tightening direction of the magnetic tape during the engagement of the two. When the stop member 4 rotates at a maximum of 1 / 2α, the stop member 4, that is, the reel 2 moves in the loosening direction with respect to the cartridge case 3 because the allowable rotation angle θ of the stop member 4 in the rotation preventing structure is αα or more. By rotating the tape, it is possible to prevent the tape from being stretched without applying a tension higher than the final rewind state to the magnetic tape.

On the other hand, the stopping gear 42 and the locking projection 27
If the reel 2 rotates at most 1 / 2α in the loosening direction of the magnetic tape during the meshing process, even if the stopping member 4 rotates in the most loosening direction at the allowable rotation angle θ, the total angle of the two in the loosening direction is When the angle is 7 ° or less, it is possible to prevent the tape from being broken without the loosened magnetic tape being entangled with the drawer member.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a magnetic tape cartridge according to an embodiment of the present invention in a non-use state.

FIG. 2 is an exploded perspective view of a main part of the magnetic tape cartridge of FIG.

FIG. 3 is a sectional view of a main part of the magnetic tape cartridge of FIG. 1 in a used state;

FIG. 4 is a plan view of a main part of FIG. 3 cut between the upper surface of the release member and the lower surface of the stopping member

FIG. 5 is a plan view of a main part of FIG. 1, which is cut at a portion of a detent protrusion of an upper case above a stopping member

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 magnetic tape cartridge 2 reel 3 cartridge case 4 restraining member 5 urging member 6 releasing member 10 reel rotation stopping means 11 drive side rotation driving means 12 rotation shaft 13 drive gear 21 reel hub 24 reel gear 26 insertion hole 27 locking projection 31 upper case 33 Non-rotating protrusion 42 Stopping gear 44 Projection 45 Locking groove 63 Push-up part α1 Pitch angle θ Allowable rotation angle

Claims (1)

[Claims] 1. A single reel wound around a magnetic tape having a substantially cylindrical drawer member at its tip is rotatably housed in a cartridge case, and the reel is allowed to rotate when used, and when not used. In a magnetic tape cartridge provided with a reel rotation restraining means for restraining rotation of the reel, the reel rotation restraining means moves so as to be able to approach and separate from the reel and engages with a locking gear and a locking projection to form a reel. A restraining member that restrains the rotation of the rotating member, a biasing member that biases the restraining member in a restraining direction, and a rotating member that rotates integrally with the reel and moves in accordance with a chucking operation of a drive-side rotation drive unit to move the restraining member. A release member that moves in the release direction, wherein the stop member is restricted from rotating by a detent structure between the cartridge case and the cartridge case. The allowable angle of rotation due to the dimensional difference is at least 1/2 of the pitch angle of the stopping gear, and the total angle of the allowable rotating angle and 1/2 of the pitch angle of the stopping gear is 7 ° or less. A magnetic tape cartridge characterized by having been set to.