JP2009064504A - Recording tape cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure stability of a releasing member (braking member) provided in a hub. <P>SOLUTION: In a recording tape cartridge provided with a reel 20 that has a hub 22 in which a reel gear 44 is formed at an outer surface of a bottom 28 and a reel plate 46 is attached, the braking member that is provided in the hub 22 so as not to rotate about a case accommodating the reel 20, and that engages with an engaging part 48 formed at an inner surface of the bottom 28 of the hub 22 to prevent the reel 20 from rotating when not used, and the releasing member 90 that has a leg part 94 which is provided between the inner surface of the bottom 28 of the hub 22 and the braking member and which is inserted into a through hole 29 formed on the reel gear 44, and that pushes up the braking member to release engagement with the engaging part 48 by pushing up the leg part 94 with a driving gear of a driving apparatus when used, a convex part 25 that defines the height of the releasing member 90 is formed at the inner surface of the bottom 28 of the hub 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording tape cartridge in which a recording tape such as a magnetic tape mainly used as a recording / reproducing medium for a computer or the like is accommodated in a case.

  Conventionally, a recording tape such as a magnetic tape used as a data recording / reproducing medium (data backup) for a computer or the like is wound around a synthetic resin reel, and the reel is housed in a single case. Cartridges are known. Such a recording tape cartridge is provided with a braking means so that the reel does not rotate in the case when not in use.

  That is, the reel includes a reel hub formed in a bottomed cylindrical shape, and a braking member serving as a braking means is non-rotatable with respect to the case and biased downward in the reel hub. Is provided. The braking member is formed of a resin material, and a braking gear is formed on the lower surface thereof. The braking gear meshes with an engaging gear formed on the bottom upper surface of the reel hub, thereby preventing the reel from rotating. It is like that.

  Further, a release member having a substantially equilateral triangular shape in a plan view formed of a resin material is provided between the bottom upper surface of the reel hub and the braking member, and the center of the lower surface of the braking member is located at the center of the upper surface of the release member. It comes to contact. At each apex portion of the release member, a leg portion protruding through a through hole formed on the reel gear formed on the bottom surface of the reel hub and projecting a predetermined height from the bottom surface of the bottom portion of the reel hub is projected. ing.

Therefore, when the recording tape cartridge is loaded into the drive device, the brake member is pushed up via the release member (leg portion) in accordance with the operation in which the drive gear formed on the rotating shaft of the drive device meshes with the reel gear. Thus, the engagement of the brake gear with the engagement gear is released. Thereby, the rotation of the reel is allowed, and the release member rotates together with the reel (for example, see Patent Document 1).
JP 2003-85930 A

  In the recording tape cartridge having such a configuration, a metal reel plate is fixed to the inside of the reel gear in the radial direction by insert molding or the like. Therefore, there is a concern that the flatness of the upper surface of the bottom of the reel hub may not be improved due to resin shrinkage during molding (cooling). If the flatness of the bottom surface of the reel hub is not good, it becomes difficult to ensure the stability (flatness) of the release member provided on the bottom surface when the recording tape cartridge is assembled, and the braking member provided on the top surface of the release member. This makes it difficult to ensure the stability (flatness) of the brake member, so that it becomes difficult to accurately move the braking member up and down after assembly.

  In view of the above circumstances, an object of the present invention is to obtain a recording tape cartridge that can ensure the stability of a release member (braking member) provided in a hub.

  In order to achieve the above object, the recording tape cartridge according to claim 1 according to the present invention has a reel gear formed on the outer surface of the bottom portion, and a metal reel plate attached to the inner side in the radial direction of the reel gear. A reel having a bottomed cylindrical resin hub, a reel having a recording tape wound around the outer peripheral surface of the hub, a case for accommodating the reel in a single rotatable manner, and a non-rotatable with respect to the case And a braking member that is provided in the hub and engages with an engaging portion formed on the bottom inner surface of the hub when not in use to prevent rotation of the reel; and an inner bottom surface of the hub A plurality of legs are provided between the brake member and inserted into a plurality of through holes formed on the reel gear, and the legs are pushed up by the drive gear of the drive device when used. And a release member made of resin that rotates together with the reel while releasing the engagement with the engaging portion by pushing up the braking member, and on the inner surface of the bottom portion of the hub, the recording tape cartridge includes: A convex portion that defines the height of the release member is formed.

  According to the first aspect of the present invention, since the convex portion that defines the height of the release member is formed on the inner surface of the bottom portion of the hub, the stability of the release member provided on the inner surface of the bottom portion of the hub can be ensured. Therefore, the stability of the braking member provided on the release member can be ensured during assembly, and the braking member can be accurately moved up and down after assembly.

  Further, the recording tape cartridge according to claim 2 is the recording tape cartridge according to claim 1, wherein the hub has a plurality of gate traces that serve as injection holes for a resin material, and overlaps the gate traces in plan view. Further, the projection is formed.

  According to the second aspect of the present invention, since the convex portion is formed on the opposite side (back side) of the gate, the fluidity of the resin material can be improved during molding, and the convex portion can be molded. Easy to do.

  According to a third aspect of the present invention, there is provided a recording tape cartridge according to the second aspect, wherein at least three convex portions are formed.

  According to the third aspect of the present invention, it is possible to satisfactorily ensure the stability of the release member provided on the inner surface of the bottom of the hub.

  Further, in the recording tape cartridge according to claim 4, in the recording tape cartridge according to claim 1, the hub has only one gate mark which is an injection port of a resin material, and around the gate mark, And the said convex part is formed in the position which avoided the gate trace in the said cancellation | release member by planar view, It is characterized by the above-mentioned.

  According to the fourth aspect of the present invention, since the release member provided on the inner surface of the bottom of the hub is supported while avoiding the gate mark, the stability of the release member can be ensured.

  A recording tape cartridge according to a fifth aspect is the recording tape cartridge according to the fourth aspect, wherein the convex portion is formed in an annular shape.

  According to the fifth aspect of the present invention, it is possible to satisfactorily ensure the stability of the release member provided on the inner surface of the bottom of the hub.

  The recording tape cartridge according to claim 6 is the recording tape cartridge according to claim 4 or 5, wherein a gate mark in the hub is formed on the inner surface of the bottom of the hub. .

  According to the sixth aspect of the present invention, since it is not necessary to form a through hole for avoiding the gate at the center of the reel plate, compared to a case where a through hole is formed at the center of the reel plate during molding. Thus, the flatness of the inner surface of the bottom of the hub can be improved.

  As described above, according to the present invention, it is possible to provide a recording tape cartridge that can ensure the stability of the release member (braking member) provided in the hub.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below in detail based on the embodiments shown in the drawings. For convenience of explanation, in FIG. 1, the loading direction of the recording tape cartridge 10 into the drive device is indicated by an arrow A, which is the forward direction (front side) of the recording tape cartridge 10. The arrow B direction orthogonal to the arrow A is the right direction (right side). A direction orthogonal to the arrow A direction and the arrow B direction is indicated by an arrow C, which is an upward direction (upper side) of the recording tape cartridge 10.

  As shown in FIGS. 1 to 3, the recording tape cartridge 10 has a case 12 having a substantially rectangular box shape. In the case 12, an upper case 14 and a lower case 16 made of resin such as polycarbonate (PC) are respectively provided with a peripheral wall 14B standing on the periphery of the top plate 14A, and a peripheral wall 16B standing on the periphery of the bottom plate 16A. Are joined together by ultrasonic welding, screwing, or the like.

  Inside the case 12, only one reel 20 is rotatably accommodated. In the reel 20, a bottomed cylindrical reel hub 22 constituting an axial center portion and a lower flange 26 provided at the lower end portion thereof are integrally formed, and the upper flange 24 is ultrasonically welded to the upper end portion of the reel hub 22. Configured. A recording tape T such as a magnetic tape as an information recording / reproducing medium is wound on the outer peripheral surface of the reel hub 22, and the end of the wound recording tape T in the width direction is wound by the upper flange 24 and the lower flange 26. Part is held.

  A reel gear 44 is formed in an annular shape on the lower surface (outer surface) of the bottom wall (bottom portion) 28 of the reel hub 22, and a gear opening for exposing the reel gear 44 to the outside is formed in the central portion of the lower case 16. 40 is drilled. The reel gear 44 exposed from the gear opening 40 is meshed with a drive gear (not shown) formed on a rotation shaft (not shown) of the drive device and is driven to rotate, whereby the reel 20 is moved in the case 12. Relative rotation with respect to the case 12 is possible.

  A reel plate 46, which is an annular metal plate made of a magnetic material, is coaxially and integrally fixed to the inner side in the radial direction of the reel gear 44 on the lower surface of the bottom wall 28 by insert molding. That is, as shown in FIGS. 5 and 6, the reel plate 46 has a plurality of small holes 47 (three in the figure) having stepped portions 47 </ b> A on the inner wall such that the lower surface has a larger diameter than the upper surface. The reel plate 46 is fixed to the lower surface of the bottom wall 28 by forming a resin material around the stepped portion 47A and solidifying it at the time of molding with a mold. The reel plate 46 is attracted and held by the magnetic force of an annular magnet (not shown) provided on the rotating shaft of the drive device.

  In the reel 20, the reel hub 22 and the lower flange 26 are integrally formed by a mold, and a gate (gate trace G) that serves as an injection port for the resin material at the time of molding is used to fix the reel plate 46. A small hole 47 is provided. That is, the reel hub 22 and the lower flange 26 are formed by a so-called three-point gate. Further, when not in use, the reel 20 partially protrudes from the inner surfaces of the upper case 14 and the lower case 16, and an idle regulation wall as an inner wall on a circular locus coaxial with the gear opening 40. 42 is held so as not to rattle.

  Further, an opening 18 for pulling out the recording tape T wound around the reel 20 is formed in the right wall 12B of the case 12, and a drive end at the free end of the recording tape T drawn out from the opening 18 has a drive. A leader pin 30 that is pulled out while being locked (engaged) by a drawing member (not shown) of the apparatus is fixed. An annular groove 32 is formed at both ends of the leader pin 30 projecting from the widthwise end of the recording tape T, and the annular groove 32 is locked to a hook or the like of the drawing member. Thereby, when the recording tape T is pulled out, the hook or the like does not come into contact with the recording tape T to be damaged.

  Further, a pair of upper and lower pin holding portions 36 for positioning and holding the leader pin 30 in the case 12 on the inner side of the opening 18 of the case 12, that is, on the inner surface of the top plate 14 A of the upper case 14 and the inner surface of the bottom plate 16 A of the lower case 16. Is provided. The pin holding portion 36 has a substantially semicircular shape with the drawing tape T drawn side open, and both end portions 34 of the leader pin 30 in an upright state can enter and leave the pin holding portion 36 from the open side. Has been.

  In addition, a leaf spring 38 is fixedly disposed in the vicinity of the pin holding portion 36, and the bifurcated tip portion of the leaf spring 38 is engaged with the upper and lower end portions 34 of the leader pin 30. The leader pin 30 is held by the pin holding portion 36. When the leader pin 30 enters and exits the pin holding portion 36, the tip of the leaf spring 38 is appropriately elastically deformed to allow movement of the leader pin 30.

  The opening 18 is opened and closed by a door 50. The door 50 is formed in a substantially rectangular plate shape having a size capable of closing the opening 18, and is provided on the top plate 14 </ b> A and the bottom plate 16 </ b> A inside the opening 18 so as to move along the right wall 12 </ b> B of the case 12. A groove portion 64 is formed in which the upper and lower end portions of 50 are slidably fitted.

  A shaft 52 is projected from the center of the rear end of the door 50, and a coil spring 58 is inserted into the shaft 52. An enlarged portion 54 that prevents the coil spring 58 from falling off is formed at the rear end of the shaft 52. Further, the lower case 16 is provided with a support base 60 having a locking portion 62 that locks the rear end of the coil spring 58 inserted into the shaft 52.

  Accordingly, the door 50 is slidably supported on the support base 60 and the rear end of the coil spring 58 is locked to the locking portion 62, so that the door 50 is always urged by the urging force of the coil spring 58. The opening 18 is biased in the closing direction. When the opening 18 is opened, it is preferable that a support base 66 that supports the shaft 52 is further protruded on the rear side of the support base 60.

  Further, a projection 56 for opening / closing operation projects outwardly from the front end of the door 50. The convex portion 56 engages with an opening / closing member (not shown) on the drive device side as the recording tape cartridge 10 is loaded into the drive device. Thereby, the door 50 is configured to be opened against the urging force of the coil spring 58.

  Further, as shown in FIGS. 2 and 3, a write protect 70 is set at the left rear portion of the case 12 so as to be slidable in the left-right direction. An opening 68 is formed in the rear wall for projecting an operation projection 72 for manually operating the write protect 70. The opening 68 is formed by a notch 68A formed in the peripheral wall 14B of the upper case 14 and a notch 68B formed in the peripheral wall 16B of the lower case 16 when the upper case 14 and the lower case 16 are joined. It is the structure formed.

  Furthermore, the lower case 16 is provided with a long hole 69 that exposes the protrusion 74 of the write protect 70 in the left-right direction, and when the recording tape cartridge 10 is loaded in the drive device, the drive The position of the write protect 70 is detected on the apparatus side, and it is automatically determined whether or not recording on the recording tape T is possible. The protrusion 74 does not protrude from the lower surface of the lower case 16.

  Also, as shown in FIGS. 4 and 6, a plurality of engagement gears 48, each set of two (a set of engagement gears 48) are spaced apart at equal intervals (e.g., at equal intervals) on the periphery of the upper surface of the bottom wall 28 of the reel hub 22. A plurality of through-holes 29 (three in this case) are drilled at predetermined positions on the reel gear 44 between the engaging gears 48. Has been. A plurality of standing ribs 23 whose longitudinal direction is the longitudinal direction are formed at equal intervals on the inner peripheral surface 22A of the reel hub 22.

  In addition, a disc-shaped braking member 80 formed of a resin material is provided inside the reel hub 22. As shown in FIGS. 2 and 3, a brake gear 84 that can mesh with the engagement gear 48 is formed in an annular shape on the periphery of the lower surface 80 </ b> A of the brake member 80, and the upper case 14 is formed on the upper surface of the brake member 80. An engagement protrusion 86 having a substantially cross-like shape in plan view, which is inserted downwardly from the inner surface of the top plate 14 </ b> A so as to protrude downward from the inner surface of the top plate 14 </ b> A. Is also set up to be slightly higher. As a result, the braking member 80 is not rotatable with respect to the case 12 (upper case 14), and is movable in the vertical direction within the reel hub 22. At that time, the braking member 80 is restricted from moving in the radial direction by the standing rib 23.

  A compression coil spring 98 is disposed between the upper case 14 and the braking member 80. That is, one end of the compression coil spring 98 abuts on the inner side (between the rotation restricting rib 76 and the annular protrusion 78) of the annular protrusion 78 provided on the outer side of the rotation restricting rib 76 of the upper case 14, and the other end is the braking member. 80 is arranged in contact with an annular groove 88 provided on the upper surface of 80. Due to the biasing force of the compression coil spring 98, the braking member 80 is constantly biased downward.

  Therefore, when the recording tape cartridge 10 is not in use (when not loaded in the drive device), the braking gear 84 is always meshed with the engagement gear 48 and the relative rotation of the reel 20 with respect to the case 12 is prevented. The rotation is locked. At this time, the reel 20 is pressed against the lower case 16 side by this urging force, and the reel gear 44 is exposed from the gear opening 40.

  Further, a release member 90 having a substantially equilateral triangular shape in a plan view formed of a resin material is provided inside the reel hub 22 and below the braking member 80 (between the bottom wall 28 and the braking member 80). As shown in detail in FIG. 7, the release member 90 is provided with a plurality of through holes 92 (three in the figure are hexagonal shapes) that have a predetermined shape at appropriate positions. A weight reduction of 90 is achieved.

  Further, a flat support convex portion 96 is formed at the center of the upper surface 90A of the release member 90, and a substantially hemispherical release protrusion 82 protruding from the center of the lower surface 80A of the braking member 80 comes into contact therewith. (See FIGS. 2 and 3). As a result, the contact area between the braking member 80 and the release member 90 is reduced, and the sliding resistance during use (when the reel 20 rotates) is reduced.

  For example, polyacetal (POM) is used as the material of the braking member 80, and polybutylene terephthalate (PBT) is used as the material of the release member 90, for example. In addition, a load of 4.2 N, for example, is applied to the release member 90 from the braking member 80 side by the biasing force of the compression coil spring 98.

  Further, on the lower surface of the release member 90 and at each apex portion, a leg portion 94 that protrudes from the lower surface (outer surface) of the bottom wall 28 to the reel gear 44 by a predetermined height is inserted. . As shown in FIG. 7, the leg portion 94 of the release member 90 has a substantially “D” shape in plan view in which the outer peripheral surface 94 </ b> A side facing the inner peripheral surface 22 </ b> A (see FIG. 6A) of the reel hub 22 is a flat surface. Is formed. The through hole 29 through which the leg portion 94 is inserted is also formed in a substantially “D” shape in plan view in which the outer peripheral portion 29A on the inner peripheral surface 22A side of the reel hub 22 is linear.

  With such a configuration, the reel hub 22 can be formed thicker toward the inside (the center of the reel hub 22), so that the rigidity of the reel hub 22 can be ensured and the release member 90 is provided. The recording tape cartridge 10 can also cope with an increase in recording capacity.

  Even if the thickness of the reel hub 22 is increased, there is a slight margin M (see FIG. 6A) between the inner peripheral surface 22A of the reel hub 22 and the through hole 29 (outer peripheral portion 29A) in plan view. It is desirable to be formed. With such a configuration, assembly suitability when the release member 90 is provided in the reel hub 22 is ensured.

  Further, even if the leg portion 94 and the through hole 29 are formed in a substantially “D” shape in a plan view, the inner peripheral surface 94B of the leg portion 94 and the inner peripheral portion 29B of the through hole 29 are viewed in a plan view. Since the arc surface (curved surface) has the same radius of curvature as before, the mold can be easily processed and there is no problem that the moldability (flowability of the resin material) is impaired.

  In the recording tape cartridge 10 having such a configuration, the convex portion 25 of the first embodiment that defines the height of the release member 90 will be described next. As shown in FIGS. 4 to 6, the upper surface (inner surface) of the bottom wall (bottom portion) 28 of the reel hub 22 on which the release member 90 is provided has a height of the release member 90 (the leg portion 94 protruding from the through hole 29. A plurality (three in the drawing) of convex portions 25 defining a length are formed at predetermined intervals in the circumferential direction (equal intervals).

  That is, the release member 90 is supported at a predetermined height by the convex portion 25, and a predetermined gap S is formed between the lower surface and the upper surface of the bottom wall 28 (see FIG. 5). The support height of the release member 90 can be accurately set by adjusting the protruding height of the convex portion 25, and the height of the convex portion 25, that is, the gap S, is S = 0.1 mm or more. It is desirable that Further, the convex portion 25 protrudes from the back surface side of the small hole 47 which is the gate mark G (gate), that is, the upper surface of the bottom wall 28 and overlaps the small hole 47 in plan view (FIG. 6). reference).

  That is, the reel hub 22 and the lower flange 26 shown in the figure are formed by so-called three-point gates in which three gate marks G are formed at equal intervals, so that three convex portions 25 are also formed at equal intervals. As described above, it is preferable that at least three convex portions 25 are formed (at equal intervals) because a plane can be defined. However, the number of the convex portions 25 is not limited to three. In addition, as long as the upper surface has a planar shape, the convex portion 25 is not limited to a substantially rectangular shape (rectangular shape) in plan view, and may be formed in, for example, a circular shape in plan view. .

  Next, the operation of the recording tape cartridge 10 including the reel 20 having the above-described configuration will be described. In the recording tape cartridge 10, the opening 18 is closed by the door 50 when not in use (when stored or transported). The braking member 80 is positioned at the rotation lock position by the urging force of the compression coil spring 98, and the braking gear 84 is engaged with the engaging gear 48. For this reason, the reel 20 is prevented from rotating with respect to the case 12.

  Further, the release member 90 has its leg portion 94 protruding from the through hole 29 on the reel gear 44 to the lower surface (outer surface) side of the bottom wall 28. At this time, the height of the release member 90 is regulated to a predetermined height by the convex portions 25 arranged at equal intervals in the circumferential direction. That is, the release member 90 is supported by the convex portion 25 so that a predetermined gap S is formed between the lower surface and the upper surface (inner surface) of the bottom wall 28. Therefore, the height position of the braking member 80 supported by the release member 90 is also defined, and the braking gear 84 and the engagement gear 48 are accurately meshed with each other.

  When the recording tape T is used, the recording tape cartridge 10 is loaded into the drive device along the arrow A direction with the front wall 12A at the head. Then, first, the opening / closing member provided on the drive device side engages with the convex portion 56 of the door 50. In this state, when the recording tape cartridge 10 further moves in the arrow A direction, the opening / closing member moves the projection 56 relatively rearward against the urging force of the coil spring 58. Then, the door 50 on which the convex portion 56 projects is slid rearward in the groove portion 64 along the right wall 12B to open the opening 18.

  Thus, when the recording tape cartridge 10 is loaded into the drive device at a predetermined depth and the opening 18 is completely opened, the recording tape cartridge 10 is lowered by a predetermined height, and the positioning member (not shown) of the drive device is moved to the lower case. 16 is inserted into a positioning hole (not shown) formed in 16. Thus, the recording tape cartridge 10 is accurately positioned at a predetermined position in the drive device, and further sliding (rearward movement) of the door 50 is restricted.

  Further, by the lowering operation of the recording tape cartridge 10, the rotating shaft relatively enters from the gear opening 40 and meshes the drive gear with the reel gear 44. Then, as the drive gear meshes with the reel gear 44, the leg portion 94 protruding on the reel gear 44 is pushed up against the urging force of the compression coil spring 98, and the braking member is interposed via the release member 90. 80 is pushed upward, and the meshing between the brake gear 84 and the engagement gear 48 is released.

  At this time, since the height position of the release member 90 is defined by the convex portion 25, the protruding amount of the leg portion 94 from the through hole 29 is also defined to a predetermined amount. Therefore, the lift amount of the release member 90 that is pushed up when the drive gear of the rotary shaft and the reel gear 44 mesh with each other is also defined, whereby the braking gear 84 can be reliably separated from the engagement gear 48 (meshing is released). )

  In this way, the engagement between the brake gear 84 and the engagement gear 48 is completely released, and the reel plate 46 is annularly provided on the radially inner side of the drive gear in a state where the drive gear and the reel gear 44 are completely engaged. By being attracted and held by the magnetic force of the magnet, the reel 20 is brought into an unlocked state in which the reel gear 44 can be rotated relative to the case 12 in the case 12 while maintaining the meshing of the reel gear 44 with the drive gear. .

  On the other hand, a drawing member provided on the drive device side enters the case 12 from the opened opening 18 and grips and pulls out the leader pin 30 positioned and held by the pin holding portion 36. At this time, since the recording tape cartridge 10 is accurately positioned in the drive device, the drawing member can reliably engage the hook with the annular groove 32 of the leader pin 30. Further, since the rotation lock state of the reel 20 is released, the reel 20 can rotate as the leader pin 30 is pulled out.

  Thus, the leader pin 30 extracted from the opening 18 is accommodated in a take-up reel (not shown). Then, by rotating the take-up reel and the reel 20 synchronously, the recording tape T is sequentially drawn out from the case 12 while being taken up by the take-up reel, and is arranged along a predetermined tape path. Information is recorded or reproduced by a recording / reproducing head (not shown).

  When the recording tape cartridge 10 that has finished recording and reproducing information is ejected from the drive device, first, the recording tape T is rewound onto the reel 20 by the reverse rotation of the rotating shaft. When the recording tape T is rewound to the end of the reel 20 and the leader pin 30 is held by the pin holding portion 36, the recording tape cartridge 10 is raised by a predetermined height, and the positioning member is moved from the positioning hole. At the same time, the rotary shaft is extracted from the gear opening 40 and the engagement of the drive gear with the reel gear 44 is released.

  Then, due to the urging force of the compression coil spring 98, the braking member 80 and the release member 90 are pressed downward, and the leg portion 94 is inserted into the through-hole 29 so as to be placed on the reel gear 44 from the lower surface (outer surface) of the bottom wall 28. The brake gear 84 meshes with the engagement gear 48 while projecting a predetermined amount. As a result, the reel 20 is again in a rotation-locked state in which relative rotation in the case 12 is prevented, and then the recording tape cartridge 10 is moved in the direction opposite to the arrow A direction by an unillustrated ejecting mechanism.

  Then, with this movement, the door 50 slides in the closing direction of the opening 18 by the urging force of the coil spring 58 and completely closes the opening 18 (returns to the initial state). Thus, the relative rotation of the reel 20 with respect to the case 12 is locked, and the recording tape cartridge 10 with the opening 18 closed is completely ejected from the drive device.

  Here, the operation of the reel 20 on which the convex portion 25 of the first embodiment is formed will be described. On the upper surface (inner surface) of the bottom wall 28 of the reel 20, a convex portion 25 that defines the height of the release member 90 is formed. Therefore, when the recording tape cartridge 10 is assembled, the mounting stability of the release member 90 provided on the upper surface (inner surface) of the bottom wall 28 of the reel hub 22 can be ensured. As a result, the mounting stability of the braking member 80 provided on the upper surface of the release member 90 can be ensured, so that the braking member 80 can be accurately moved up and down after the recording tape cartridge 10 is assembled.

  Moreover, the convex part 25 is formed in the other side (back side) of a gate (gate trace G). Here, the portion immediately above the gate (gate trace G) is a portion that is likely to rise due to the pressure of the resin material injected from the gate. Therefore, by forming the convex portion 25 on the upper surface of the bottom wall 28 immediately above the gate (gate trace G), the fluidity of the resin material can be improved during molding, and the convex portion 25 can be easily molded. it can. Further, since the convex portions 25 are formed at least three (at equal intervals), the stability of the release member 90 provided on the upper surface of the bottom wall 28 of the reel hub 22 is excellent when the recording tape cartridge 10 is assembled. Can be secured.

  Next, the convex part 27 of 2nd Example which prescribes | regulates the height of the cancellation | release member 90 is demonstrated. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 1st Example, and detailed description (a common effect | action is also included) is abbreviate | omitted. As shown in FIGS. 8 and 9, in this reel 20, the gate (gate mark G) for integrally forming the reel hub 22 and the lower flange 26 is the center of the lower surface (outer surface) of the bottom wall (bottom portion) 28. ing.

  Here, since the gate trace G is normally formed so as to be raised, the periphery of the gate trace G is formed as a concave portion 28A having a circular shape when viewed from the bottom, so that the gate trace G does not protrude from the lower surface of the bottom wall 28. ing. Further, the gate (gate trace G) of the release member 90 is formed at the center of the lower surface as shown in FIGS. 3 and 7, and the gate trace G does not protrude from the lower surface around the gate trace G. A concave portion 95 having a circular shape in bottom view is formed.

  Therefore, as shown in FIGS. 8 and 9, the convex portion 27 is formed in the center of the upper surface (inner surface) of the bottom wall (bottom portion) 28 in an annular shape coaxial with the rotation center of the reel 20 and the gate ( The gate mark G), that is, a position avoiding the recess 95 is formed. That is, the convex portion 27 is provided in the vicinity of the periphery of the gate (gate trace G) and in the vicinity of the concave portion 95 of the release member 90 in order to improve the fluidity of the resin material injected from the gate (gate trace G). It is formed in an annular shape with an inner diameter R that can support the lower surface.

  Therefore, in this case, as in the first embodiment, the stability of the release member 90 provided on the upper surface of the bottom wall 28 of the reel hub 22 can be ensured when the recording tape cartridge 10 is assembled. The height of the projection 27, that is, the gap S formed between the lower surface of the release member 90 and the upper surface of the bottom wall 28 is the same as that in the first embodiment. Also in the case of the second embodiment, the support height of the release member 90 can be accurately set by adjusting the protruding height of the convex portion 27.

  Moreover, the shape of this convex part 27 is not limited to the continuous cyclic | annular form like illustration, For example, you may form in the intermittent substantially cyclic | annular form. However, when the convex portion 27 is formed in a continuous annular shape, the stability of the release member 90 provided on the upper surface of the bottom wall 28 of the reel hub 22 can be satisfactorily ensured when the recording tape cartridge 10 is assembled. So desirable.

  Further, as shown in FIG. 10, in this second embodiment, the gate (gate mark G) for integrally forming the reel hub 22 and the lower flange 26 is the upper surface of the bottom wall (bottom) 28 to which the reel plate 46 is not fixed. It may be the center of the (inner surface). In this case, a recess 28 </ b> B having a circular shape in plan view is formed around the gate (gate trace G) on the upper surface of the bottom wall 28 so that the gate trace G does not protrude from the upper surface of the bottom wall 28.

  Thus, when the gate (gate trace G) is provided on the upper surface of the bottom wall 28, it becomes a deformation factor of the bottom wall 28 at the center of the reel plate 46 (in order to avoid it when the gate is the lower surface of the bottom wall 28). The through hole 46A (refer to FIG. 9) is not required, that is, the reel plate 46 in which the through hole 46A is not formed at the center can be insert-molded, so that the through hole 46A is formed at the center. Compared with the case where the formed reel plate 46 is insert-molded, the flatness of the upper surface of the bottom wall 28 of the reel hub 22 can be improved.

  That is, with such a configuration, the stability of the release member 90 provided on the upper surface of the bottom wall 28 of the reel hub 22 can be further ensured when the recording tape cartridge 10 is assembled. Although not shown, both the convex portion 25 and the convex portion 27 that define the height of the release member 90 may be formed on the upper surface (inner surface) of the bottom wall (bottom portion) 28 of the reel hub 22.

  As described above, since the convex portions 25 and 27 that define the height of the release member 90 are formed on the upper surface (inner surface) of the bottom wall (bottom portion) 28 of the reel hub 22, at the time of assembling the recording tape cartridge 10. The release member 90 can be stably provided in the reel hub 22 (the upper surface of the bottom wall 28). Therefore, the braking member 80 can also be provided stably, and the release member 90 and the braking member 80 can be moved up and down stably after the recording tape cartridge 10 is assembled. As a result, the braking gear 84 and the engagement gear 48 can be reliably engaged and released.

  In the recording tape cartridge 10 of the above embodiment, the leader pin 30 is provided as a leader member. However, the recording tape cartridge 10 is not limited to the above embodiment, and for example, a leader tape (not shown) is used as the leader member. (Omitted). Further, the recording tape T only needs to be grasped as a long tape-like information recording / reproducing medium capable of recording information and reproducing the recorded information, and the recording tape cartridge 10 according to the present invention can perform any recording. Needless to say, the present invention can also be applied to a recording tape T of a reproducing system.

Schematic perspective view of recording tape cartridge Schematic exploded perspective view of the recording tape cartridge as viewed from above Schematic exploded perspective view of the recording tape cartridge as viewed from below The schematic perspective view which shows the structure of the bottom wall upper surface of the reel hub of 1st Example. Schematic sectional view showing the configuration of the reel hub of the first embodiment provided with a release member (A) Schematic plan view of the reel hub of the first embodiment, (B) Schematic bottom view of the reel hub of the first embodiment. Schematic bottom view of release member The schematic perspective view which shows the structure of the bottom wall upper surface of the reel hub of 2nd Example. Schematic sectional view showing the configuration of the reel hub of the second embodiment provided with a release member Schematic sectional view showing the configuration of the reel hub of the second embodiment provided with a release member and having a gate formed on the upper surface of the bottom wall

Explanation of symbols

10 Recording Tape Cartridge 12 Case 20 Reel 22 Reel Hub (Hub)
24 Upper flange 25 Projection 26 Lower flange 27 Projection 28 Bottom wall (bottom)
29 Through-hole 30 Leader pin 44 Reel gear 46 Reel plate 47 Small hole 48 Engagement gear (engagement part)
50 Door 70 Write protect 80 Brake member 82 Release protrusion 84 Brake gear 90 Release member 92 Through hole 94 Leg 95 Recess 96 Support protrusion G Gate trace T Recording tape

Claims (6)

A reel gear is formed on the outer surface of the bottom, and a cylindrical resin hub with a bottom having a metal reel plate attached to the inner side in the radial direction of the reel gear. A recording tape is wound around the outer peripheral surface of the hub. Reels,
A case that accommodates the reel in a rotatable manner;
A braking member that is not rotatable with respect to the case and is provided in the hub, and engages with an engaging portion formed on an inner surface of the bottom of the hub to prevent rotation of the reel when not in use. ,
A plurality of legs are provided between the inner surface of the bottom of the hub and the braking member, and inserted into a plurality of through holes formed on the reel gear. A resin release member that rotates with the reel while pushing up the braking member to release the engagement with the engagement portion by pushing up the leg portion,
In a recording tape cartridge comprising:
A recording tape cartridge, wherein a convex portion defining a height of the release member is formed on an inner surface of a bottom portion of the hub.   The recording tape cartridge according to claim 1, wherein the hub has a plurality of gate traces serving as injection holes for a resin material, and the convex portions are formed at positions overlapping the gate traces in plan view. .   The recording tape cartridge according to claim 2, wherein at least three convex portions are formed.   The hub has only one gate mark which is an injection port for the resin material, and the convex portion is formed around the gate mark and at a position avoiding the gate mark in the release member in plan view. The recording tape cartridge according to claim 1.   The recording tape cartridge according to claim 4, wherein the convex portion is formed in an annular shape.   6. The recording tape cartridge according to claim 4, wherein a gate mark in the hub is formed on an inner surface of a bottom portion of the hub.

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