JP2000067558A - Magnetic tape cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute sure releasing operation by providing a reel rotation blocking means with a blocking member and a releasing member, passing the pushing up parts of this releasing member into the insertion holes of a reel gear, forming their front ends contactably with a drive gear and opening the insertion holes in a range including the tips of the reel gear and the tooth grooves between the tips. SOLUTION: The reel rotation blocking member 10 has the blocking member 4 which moves vertically attachably and detachably to and from a reel 2, an energizing member which energizes the blocking member 4 in a blocking direction and the releasing member 6 which moves in a releasing direction. The insertion holes 26 penetrated and formed at the reel gear 24 of the reel 2 are opened within a range inclusive of at least one tooth grooves in the rotating direction of the reel gear 24. The insertion holes 26, i.e., the front end faces of the pushing up parts 63 are formed to include the one tooth groove and more when the tip positions of the drive gear do not exist in the final meshing position with the reel gear 24 and mesh with the deviation in phase in the range of one pitch in the meshing process thereof, by which the tips of the drive gear is pressed to the front end faces of the pushing up parts 63.

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 order to improve the reliability of the operation of the above-described reel rotation stopping means and to prevent dust from entering the cartridge case, the reel rotation stopping means restricts the rotation of the reel. And a release member that moves the stop member in the release direction by moving in response to the chucking operation of the drive-side rotation drive unit. May be provided.

In other words, in the non-use state, the magnetic tape is not pulled out by restraining the reel from being inadvertently rotated by the stopping member. When the reel is chucked, the release member moves in conjunction with the operation to release the stop member. In this state, the reel is rotatable, and the magnetic tape can be pulled out and wound up.

In the above-described mechanism, the pressing position for releasing the releasing member accompanying the chucking operation by the drive-side rotary driving means is performed at a plurality of positions on the outer peripheral portion rather than at one position at the central portion. It is more preferable that a stable releasing operation can be performed. At this time, the reel is provided with a reel gear that meshes with the drive gear of the drive-side rotation drive means, and a push-up portion formed on a part of the release member is brought into contact with the drive gear through a through hole provided in the reel gear. It is advantageous to provide a structure in which the push-up portion is pressed by the drive gear to release the release member during the chucking operation of the drive-side rotary drive means, in order to simplify the structure and the like.

However, the opening of the insertion hole through the reel gear as described above reduces meshing between the reel gear and the drive gear, which is a problem in reliable driving of the reel. If the insertion hole is made smaller from this point, the shape of the push-up portion of the release member inserted into this insertion hole also becomes smaller, which makes it difficult to accurately contact the tips of the teeth of the drive gear to obtain a reliable pressing operation. May be stable.

When an insertion hole is opened in the reel gear, the edge of the insertion hole opened in the tooth portion may be formed in an edge shape corresponding to the uneven shape of the gear teeth. May cause strength problems in the meshing of the release members or in the formation of the release member.

Further, when the push-up portion is formed on a part of the release member as described above, and the push-up portion is inserted into the insertion hole of the reel and is slid, the release member is urged by the biasing force of the biasing member. As a result, a bending force is exerted on the push-up portion, and a part of the outer surface is pressed against the inner surface of the insertion hole to increase the frictional resistance. There is a possibility that the movement is hindered and the release member cannot release the stopping member reliably.

The present invention has been made in view of the above points, and has as its object to provide a magnetic tape cartridge capable of performing a reliable releasing operation of a releasing member of a reel rotation stopping means.

[0011]

According to a magnetic tape cartridge of the present invention which solves the above problems, a single reel on which a magnetic tape is wound is rotatably accommodated in a cartridge case, and the reel is rotated during use. A reel rotation restraining means for permitting and restricting the rotation of the reel when not in use, wherein the reel rotation restraining means moves so as to be able to approach and separate from the reel and restrains the rotation of the reel. An urging member for urging the restricting member in the restricting direction, and a releasing member for rotating integrally with the reel and moving in accordance with the chucking operation of the drive-side rotation driving means to move the restricting member in the releasing direction. A reel gear that meshes with a drive gear of a drive-side rotary drive unit, and a push-up formed on a part of the release member is provided on the reel gear. It becomes the tip through the hole is contactable to said drive gear, is characterized in that the tooth spaces between the insertion hole of the tooth tip of the reel gear and the addendum opened on at least one contains range.

Specifically, the insertion hole is opened between the teeth of the reel gear. Alternatively, the insertion hole is opened across two or more teeth of the reel gear, and the teeth that are opened by the insertion hole are removed.

It is preferable that a concave portion is formed on a distal end surface of the release member, which is in contact with the drive gear, in which a tooth tip of the drive gear can be engaged.

Further, in another magnetic tape cartridge of the present invention, a reel is provided with a reel gear meshing with a drive gear of a drive-side rotary driving means, and a push-up formed in a part of a release member is provided in the reel gear. The push-up portion and the insertion hole are brought into contact with each other through a minute projection for reducing a contact area, with the tip provided so as to be able to contact the drive gear.

[0015]

According to the magnetic tape cartridge of the present invention as described above, the insertion hole formed in the reel gear of the reel rotation restraining means is opened in a range including at least one tooth gap between the teeth of the reel gear. As a result, the tip of the drive gear meshing with the reel gear can reliably contact and press the push-up portion of the release member protruding through the insertion hole even in the small insertion hole, and the release member can be stably moved. Accordingly, the stopping member can be reliably released by a predetermined moving amount, and the operation reliability of the reel rotation stopping means can be ensured.

Further, in the case where the insertion hole is opened over two or more teeth of the reel gear and the teeth where the insertion hole is opened are removed, there is no gear tooth at the opening of the insertion hole, and the opening edge is formed. Thus, the problem of strength of the molded article can be solved and the moldability can be improved.

According to another magnetic tape cartridge of the present invention, the push-up portion provided on the release member of the reel rotation stopping means is brought into contact with the insertion hole provided on the reel via the minute projection for reducing the contact area. As a result, the frictional resistance between the two members is reduced, and even when the release member is bent, the push-up portion can be stably moved in accordance with the chucking operation of the drive-side rotation driving means, and the stopping member can be reliably moved with a predetermined movement amount. Can be released at the same time and the movement to the stop state can be secured,
The operation reliability of the reel rotation stopping means can be ensured.

[0018]

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.

The reel 2 has a bottomed cylindrical reel hub 21 around which a magnetic tape is wound around the outer periphery, and a lower flange portion 22 and an upper flange portion which respectively protrude radially from the outer periphery of the upper and lower ends of the reel hub 21. 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 fixed. Then, the reel gear 24 of the reel 2
The reel plate 25 is disposed so as to face the opening 32 a on the bottom surface of the cartridge case 3. The reel 2 is urged downward by an urging member 5 described later.

The drive-side rotary drive means 11 includes 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 of a synthetic resin molded product 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 equal intervals on the circumference, and three locking projections 27 are erected on the upper surface of the bottom wall 21a at equal phases on the circumference at a different phase position from the insertion hole 26, This locking projection 2
7 is formed in a gear tooth shape. Note that three or more insertion holes 26 and locking projections 27 may be arranged, and the tip of the locking projection 27 may have a plurality of gear tooth shapes. The reel 2 shown in FIG. 2 shows a state where only the bottom wall 21a is cut off.

The stop 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. 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 protrude in a convex shape, and contacts the center of the upper surface of the disk portion 61 of the release member 6 described later.

Further, a protrusion 44 is formed on the upper surface of the disc 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
The rotation preventing projection 33 inserted into the locking groove 45 is provided upright on the inner surface of 1. 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 4
The detent 5 and the detent protrusion 3 may be provided in a single character shape, or the detent projection may be formed on the restraining member 4 and the locking groove may be formed on the upper case 31.

A biasing member 5 formed by a coil spring is contracted 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. Further, the stopping member 4 is urged 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. The arm portion 62 is formed so as to extend in the radial direction at three locations on the outer periphery of the disk portion 61 on the center side. Are provided with prism-shaped push-up portions 63 extending vertically. Each of the push-up portions 63 is movably inserted into an insertion hole 26 opened in the reel hub 21 so that the push-up portion 63 can move in and out, and its tip is located facing the tooth portion of the reel gear 24 on the lower surface of the reel hub 21. At this time, the locking projections 27 are located between the arms 62. The push-up portion 63 may be formed in a columnar shape, an elliptical column shape, or the like. Also,
The disk portion 61 and the arm portion 62 may be integrally provided in a substantially triangular shape.

When the release member 6 is at the lowest position (FIG. 1), the leading 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. Further, the stopping member 4 is urged by the urging member 5 so that the front end of the convex portion at the center of the lower surface thereof comes into contact with the upper surface of the releasing member 6, and both members come into sliding contact with each other.

An insertion hole 26 formed through the reel gear 24 of the reel 2 is opened in a range including at least one tooth groove (a groove portion between tooth tips) in the rotation direction of the reel gear 24. . The insertion hole 26 is opened in a rectangular shape, a circular shape, an elliptical shape, or the like according to the cross-sectional shape of the push-up portion 63.

For example, as shown in the embodiment of FIG.
The insertion hole 26 is provided at a tooth tip 24 a adjacent to the reel gear 24.
It is opened at a width of one pitch in a tooth groove portion between the tooth tip 24a. Push-up portion 6 of release member 6 inserted into insertion hole 26
3, the center of the tooth groove of the reel gear 24 coincides with the center of the tooth groove of the reel gear 24. In the illustrated example, the side angles of the teeth of the reel gear 24 are the same on both sides. Matches.

The opening width of the insertion hole 26 is determined by the reel gear 2.
4 is the minimum, and when the outer diameter of the reel gear 24 is small or the number of teeth is large and the pitch is small, or when the push-up portion 63 is provided large, the following description is made with reference to FIG. Alternatively, as shown in FIG. 8, the opening is formed to be equal to or larger than the size of one tooth space. In this case, at least one tooth space is included, and both sides or one side thereof have a wide range of insertion holes 26.
Is opened.

As a result, when the reel gear 24 meshes with the drive gear 13, the tooth tip position of the drive gear 13 is not at the final meshing phase with the reel gear 24, and the phase shifts within one pitch in the meshing process. At the time of engagement, the tip end of the drive gear 13 always contacts the distal end surface of the push-up portion 63 because the insertion hole 26, that is, the distal end surface of the push-up portion 63 is formed to include more than one tooth groove. It can be pushed up by contact. The same applies to the case where the center of the tooth groove of the reel gear 24 (drive gear 13) and the position of the tooth bottom do not match, and the side angles of the teeth are different on both sides.

At least one of the stopping member 4 and the releasing member 6 is made of molybdenum disulfide, polytetrafluoroethylene, graphite (graphite), potassium titanate whisker, silicone (dimethylpolysiloxane of various grades and modified products thereof). And the like, may be molded with a synthetic resin containing a lubricant such as the above to improve the slipperiness. In addition to the above lubricants, oleamide amide lubricants, erucamide amide lubricants, stearamide amide lubricants, bisfatty acid amide lubricants, nonionic surfactant lubricants, hydrocarbon lubricants, fatty acid lubricants, ester lubricants A lubricant such as an alcohol-based lubricant and a metallic soap may be added. Further, as synthetic resins, PC (polycarbonate), POM (polyoxymethylene), glass fiber-containing ABS (acrylonitrile butadiene styrene), PPS, nylon 6
Or a resin excellent in abrasion resistance having an imide group such as an aliphatic polyamide such as nylon 66, an aromatic polyamide, an ultrahigh molecular weight polyethylene, an isotactic polypropylene, a syndiotactic polystyrene, a polyimide or a polyamideimide or a polyetherimide. It is preferred to use As a result, the friction and wear of the sliding contact portions of the two are reduced, and the reel 2 can be rotated stably due to the reduction of the driving resistance, and the generation of wear powder is suppressed to ensure the reliability of the recording / reproducing performance. be able to.

The operation of the reel rotation stopping means 10 will be described. FIG. 1 shows a state where 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.
3 engages with the reel gear 24 and moves the reel 2 slightly upward with respect to the case 3 to hold it.
Of the release member 6 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.

In the release state, the release member 6 is pressed with the tip of the drive gear 13 securely contacting the tip of the push-up portion 63, and the push-up movement can be performed linearly and stably. The stopping member 4 is moved by a predetermined stroke amount, so that the engagement between the stopping gear 42 and the locking projection 27 can be reliably released.

FIG. 5 shows another embodiment of the release member 6, which is formed in the same manner as the embodiment of FIG. 4 except that the shape of the tip of the push-up portion 63 is different.

The push-up portion 63 has the insertion hole 26 opened in the tooth groove portion between the tooth tips 24a of the reel gear 24 in the same manner as described above.
And the drive gear 1 of the drive-side rotation drive means 11
A concave portion 63a with which the tooth tip of the drive gear 13 can be engaged is formed at the center of the distal end surface that comes into contact with 3.

The driving gear 1 in the recess 63a of the push-up portion 63
The engagement depth h with the reel gear 24 and the drive gear 13 is H, and the engagement depth (that is, the release height) between the stopping gear 41 and the locking projection 27 is D (not shown). ), It is necessary to ensure that the effective lifting height Hh of the push-up portion 63 is sufficiently larger than the release height D, that is, Hh≫D, to ensure the release operation.

The push-up portion 63 of this embodiment has a recess 6
3A, the chucking operation of the drive-side rotation driving means 11 starts from non-use in FIG.
As shown in (B), the tooth tip of the driving gear 13 is
3a, the release member 6 can be reliably pushed up from the initial stage of the ascent of the drive gear 13.

FIG. 6 shows another embodiment of the reel gear 24. The reel gears 2 on both sides where the insertion holes 26 are opened.
The tip of the fourth tooth tip 24a is removed flat. Instead of the flat shape, the tip removal shape may be an R shape for removing a curved surface or a C shape for removing a chamfered slope.

In the present embodiment, the tooth tip 24a of the reel gear 24 at the opening end of the insertion hole 26 is sharpened in an edge shape as it is. It becomes easy and the moldability is improved.

FIG. 7 shows another embodiment of the insertion hole 26. The insertion hole 26 extends over two teeth of the reel gear 24.
Are formed in a wider area than the tooth space between the tooth tips 24a, and a flat surface 24b is formed around the opening of the insertion hole 26 by removing a tooth (indicated by a chain line) from the root of the insertion hole 26.

In the present embodiment, the width of the insertion hole 26 is larger than one pitch of the reel gear 24 and is formed in a range including the tooth gap 24a on both sides including one tooth groove, and the phase is shifted from the reel gear 26. Even when the drive gear 13 meshes with the drive gear 13 in this state, the tooth tip of the drive gear 13 always comes into contact with the tip end surface of the push-up portion 63, and a reliable push-up operation can be obtained. Also,
Since low teeth are removed so as not to remain at the edge of the insertion hole 26 and no edge-shaped teeth are formed around the opening of the insertion hole 26, molding is easy and strength is advantageous.

FIG. 8 shows another embodiment of the insertion hole 26, and the gear teeth of the reel gear 24 are different. The tip 24a of the reel gear 24 has a flat tip at the outer periphery, a sharp tip at the inner periphery, and a reduced height. An insertion hole 26 having an inner diameter of approximately two pitches is provided across the two gear teeth, and is opened to the bottom of the adjacent tooth groove over the gear teeth on both sides with the center at the bottom of the central tooth groove. Further, the two teeth having the insertion holes 26 opened are removed from the roots to form flat portions 24b.

Also in this embodiment, the width of the insertion hole 26 is larger than one pitch of the reel gear 24 and is formed in a range of approximately half of the tooth grooves on both sides including one tooth groove. Always comes into contact with the front end face of the push-up portion 63, and a reliable push-up operation can be obtained. In addition, since the teeth that open the insertion hole 26 are removed and the edge-shaped teeth are not formed around the opening of the insertion hole 26, molding is easy and the strength is advantageous.

FIGS. 9 and 10 show another embodiment of the release member 6, in which the release member 6 is formed by pressing a metal plate.

That is, in FIG. 9, the metal plate is
Of the disk portion 61, the arm portion 62, and the push-up portion 63, and the extended portion of the distal end of the arm portion 62 is bent downward to form the push-up portion 63, and the distal end portion is further bent inward to form the contact portion 63b. Is formed.
Note that the contact portion 63b may be formed with the plate thickness of the push-up portion 63 without bending.

In the example shown in FIG. 10, a push-up portion 63 bent downward from the side is connected to the tip of the arm portion 62, and the tip portion is further bent to form the contact portion 63b.

The release member 6 formed by the above-described sheet metal press can easily secure rigidity, and can be designed to have a thickness such that the rigidity of the synthetic resin molded product is insufficient. The installation space for the reel 10 can be easily secured, and the meshing area of the reel 2 with the drive-side rotation driving means 11 can be increased with the downsizing of the insertion hole 26 in the reel gear 24.

FIGS. 11 and 12 show another embodiment of the insertion hole 26 and the push-up portion 63. The inner peripheral surface of the insertion hole 26 formed through the reel gear 24 of the reel 2. FIG. And the outer peripheral surface of the push-up portion 63 of the release member 6 is configured to come into contact via a minute projection provided on any surface to reduce the contact area.

First, in the example of FIG. 11A, the push-up portion 63 has a square rod shape and a smooth surface, and minute projections 26 a are formed on the inner surface of the insertion hole 26 in the vertical direction along the moving direction of the push-up portion 63. ing. In the example of FIG. 11B, the insertion hole 26 is a square hole and the inner surface is smooth, and the minute protrusion 63d is formed on the surface of the square rod-shaped push-up portion 63 in the vertical direction along the moving direction. The small projections 26a and 63d have a height of about several tens of micrometers, and are exaggerated in the drawings.

Further, FIG. 12 shows another embodiment in which the push-up portion 63 is formed in a round bar shape, and minute projections for reducing the contact area are formed on the inner surface of the insertion hole 26 formed in a square hole shape. Is provided.

That is, in the example of FIG. 12A, the surface of the push-up portion 63 having a round bar shape is smooth, and a plurality of minute projections 26 a are formed on the inner surface of the insertion hole 26 on each surface along the moving direction of the push-up portion 63. It is formed in the vertical direction. In the example of FIG.
The surface of the push-up portion 63 in the shape of a round bar is smooth, and minute projections 26 a are formed on the inner surface of the insertion hole 26 at the center of each surface in the vertical direction along the moving direction of the push-up portion 63. It should be noted that minute protrusions for reducing the contact area may be provided on the surface of the round bar-shaped push-up portion 63, and the insertion hole 26 may be formed in a round hole shape.

In this embodiment, when the reel rotation restraining means 10 moves from the restrained state to the released state or from the released state to the restrained state, the outer peripheral surface of the push-up portion 63 of the releasing member 6 and the insertion hole of the reel 2 are moved. Since the inner peripheral surface of the push-up portion 26 is in contact with the inner peripheral surface through the minute protrusion 26a or 63d that reduces the contact area, the frictional resistance is reduced, and the push-up portion 63 is moved stably and reliably.

[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 vertical cross-sectional view of the insertion hole of the reel and the push-up portion of the release member in FIG. 1;

FIG. 5 is a cross-sectional view of a main part showing another embodiment of the push-up portion of the release member before and after the chucking operation.

FIG. 6 is a sectional view of a main part showing another embodiment of a reel gear.

FIG. 7 is a sectional view showing another embodiment of the insertion hole of the reel gear and the push-up portion of the release member.

FIG. 8 is a bottom view of a main part showing still another embodiment of the insertion hole of the reel gear.

FIG. 9 is a perspective view showing another embodiment of the release member.

FIG. 10 is a perspective view showing still another embodiment of the release member.

FIG. 11 is a cross-sectional view showing another embodiment of the insertion hole of the reel and the push-up portion of the release member.

FIG. 12 is a cross-sectional view showing still another embodiment of the insertion hole of the reel and the push-up portion of the release member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 magnetic tape cartridge 2 reel 3 cartridge case 4 stopping 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 21a bottom wall 24 reel gear 24a tooth tip 24b flat part 26 Insertion hole 26a Small protrusion 27 Locking protrusion 42 Stopping gear 62 Arm 63 Push-up 63a Recess 63b Contact portion 63d Small protrusion

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideaki Shiga 2-12-1, Ogimachi, Odawara City, Kanagawa Prefecture Inside Fuji Photo Film Co., Ltd. (72) Inventor Seiji Tsukigi 2-12-1, Ogimachi, Odawara City, Kanagawa Prefecture Fuji Photo Film Co., Ltd.

Claims (5)

[Claims] 1. A reel rotation stopping means which rotatably accommodates a single reel wound with a magnetic tape in a cartridge case, permits rotation of the reel when in use, and restricts rotation of the reel when not in use. A magnetic tape cartridge comprising: a reel rotation restricting means, a restricting member that is movable to and away from the reel to restrict rotation of the reel, and a biasing member that biases the restricting member in a restricting direction. And a release member that rotates together with the reel and moves in accordance with the chucking operation of the drive-side rotation drive unit to move the stop member in a release direction. A reel gear meshing with a gear is provided, and a push-up portion formed on a part of the release member is provided so that a leading end can contact the drive gear through an insertion hole provided in the reel gear. Becomes, the magnetic tape cartridge, characterized in that the tooth spaces between the insertion hole of the tooth tip of the reel gear and the addendum opened on at least one contains range. 2. The magnetic tape cartridge according to claim 1, wherein the insertion hole is opened between the tooth tips of the reel gear. 3. The magnetic tape cartridge according to claim 1, wherein the insertion hole is opened across two or more teeth of the reel gear, and the teeth that are opened by the insertion hole are removed. 4. The magnetic tape cartridge according to claim 1, wherein a concave portion with which a tooth tip of the drive gear can be engaged is formed on a distal end surface of the release member that contacts the drive gear. 5. A reel rotation stopping means for rotatably housing a single reel wound with a magnetic tape in a cartridge case, allowing rotation of the reel when in use, and restricting rotation of the reel when not in use. A magnetic tape cartridge comprising: a reel rotation restricting means, a restricting member that is movable to and away from the reel to restrict rotation of the reel, and a biasing member that biases the restricting member in a restricting direction. And a release member that rotates together with the reel and moves in accordance with the chucking operation of the drive-side rotation drive unit to move the stop member in a release direction. A reel gear meshing with a gear is provided, and a push-up portion formed on a part of the release member is provided so that a leading end can contact the drive gear through an insertion hole provided in the reel gear. Becomes, the magnetic tape cartridge is characterized in that in contact via the microprojections to reduce the contact area of said push-up portion and the insertion hole.