US20050199765A1 - Magnetic tape reel - Google Patents
Magnetic tape reel Download PDFInfo
- Publication number
- US20050199765A1 US20050199765A1 US11/079,217 US7921705A US2005199765A1 US 20050199765 A1 US20050199765 A1 US 20050199765A1 US 7921705 A US7921705 A US 7921705A US 2005199765 A1 US2005199765 A1 US 2005199765A1
- Authority
- US
- United States
- Prior art keywords
- reel hub
- reel
- thickness
- magnetic tape
- resin material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000000463 material Substances 0.000 claims abstract description 23
- 230000002093 peripheral effect Effects 0.000 claims abstract description 12
- 229920005989 resin Polymers 0.000 claims abstract description 12
- 239000011347 resin Substances 0.000 claims abstract description 12
- 229920000049 Carbon (fiber) Polymers 0.000 claims abstract description 10
- 239000004917 carbon fiber Substances 0.000 claims abstract description 10
- 229920003002 synthetic resin Polymers 0.000 claims description 11
- 239000000057 synthetic resin Substances 0.000 claims description 11
- 229920005668 polycarbonate resin Polymers 0.000 claims description 10
- 239000004431 polycarbonate resin Substances 0.000 claims description 10
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 3
- 239000000835 fiber Substances 0.000 claims description 3
- 238000000465 moulding Methods 0.000 description 12
- 239000002184 metal Substances 0.000 description 3
- 239000000945 filler Substances 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 238000013500 data storage Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
- G11B23/02—Containers; Storing means both adapted to cooperate with the recording or reproducing means
- G11B23/04—Magazines; Cassettes for webs or filaments
- G11B23/041—Details
- G11B23/044—Reels or cores; positioning of the reels in the cassette
Definitions
- the present invention relates to a magnetic tape reel formed of a synthetic resin material.
- magnetic tape cartridges of this type generally have a single reel which is housed in a cartridge case in a rotatable manner.
- This single reel comprises a resin reel hub around which a magnetic tape is wound, and upper and lower flanges respectively extending radially outward from the outer peripheries of the upper and lower ends of the reel hub.
- the reel hub and the lower flange are typically integrally molded of a synthetic resin material.
- the upper flange which is also formed of the same or another synthetic resin material, is fixed to the reel hub by ultrasonic welding with the upper flange being fitted to a top end of the reel hub.
- the thermal conductivity of a polycarbonate resin and the thermal conductivity of a resin material which is a polycarbonate resin containing 10% of glass fibers are respectively 0.2 W/(m ⁇ K) and 0.23 W/(m ⁇ K), whereas the thermal conductivity of a resin material which is a polycarbonate resin containing 10% of carbon fibers is 0.45 W/(m ⁇ K), or as much as approximately twice those of the polycarbonate resin and the resin material containing 10% of glass fibers.
- the curing time during molding is relatively short, whereby the resin material becomes difficult to flow to a cavity portion located far from a gate of a molding die.
- the thickness of the flange of reel is typically as low as half the thickness of the peripheral wall of the reel hub, and the radially outer end of the flange is remote from the gate of the molding die. Accordingly, when a resin material in which carbon fibers are incorporated is used, the difficulty of flowing of the resin material to the radially outer end of the flange causes a larger deviation in height at the radially outer end of the flange from a reference level. Further, a difference in fluidity caused between the flange portion and the reel hub portion brings a new problem that controlling of the molding conditions is difficult.
- an object of the present invention is to reduce the aforementioned difference in fluidity during molding when the resin material in which carbon fibers are incorporated is used to enhance the strength of the reel, and hence to facilitate the controlling of the molding conditions.
- a magnetic tape reel comprising a cylindrical reel hub around which a magnetic tape is wound; and upper and lower flanges respectively extending radially outward from outer peripheries of upper and lower ends of the reel hub, wherein when the reel hub and one of the upper and lower flanges are integrally molded of a synthetic resin material containing carbon fibers, a thickness t of a peripheral wall of the reel hub and a thickness t′ of one of the flanges to be integrally molded with the reel hub are selected to satisfy the relationship given by 0.8t ⁇ t′ ⁇ 1.2t.
- the thickness t of the peripheral wall of the reel hub and the thickness t′ of one of the flanges are selected to satisfy the relationship given by 0.8t ⁇ t′ ⁇ 1t.
- the aforementioned synthetic resin material is preferably a polycarbonate resin containing at least 5% of carbonate fibers.
- a greater thickness t′ of the flange results in better fluidity.
- increasing the thickness t′ of the flange and hence reducing the ratio t/t′ of the thickness t of the peripheral wall of the reel hub to the thickness t′ results in deterioration of the cylindricity of the reel hub although the deviation in height at the radially outer end of the flange from the reference level during molding is reduced.
- the thickness t′ of the flange which is integrally molded with the reel hub is selected to fall within ⁇ 20% of the thickness t of the peripheral wall of the reel hub, whereby the controlling of the molding conditions is facilitated, and it becomes possible to reduce the deviation in height at the radially outer end of the flange from the reference level while maintaining appropriate cylindricity and strength of the reel hub.
- FIGURE shows a longitudinal sectional view of a magnetic tape reel according to one embodiment of the invention.
- FIGURE is a longitudinal sectional view of an inventive reel to be incorporated in a magnetic tape cartridge.
- a reel 1 to be rotatably housed within a case of a magnetic tape cartridge comprises: a reel hub 2 which is shaped in the form of a tubular member with an outer diameter of about 40 mm, a closed bottom and an open top, and around which a magnetic tape is wound; and lower and upper flanges 3 and 4 respectively extending radially outward from the outer peripheries of the upper and lower ends of the reel hub 2 .
- the reel hub 2 and the lower flange 3 are integrally molded of a synthetic resin material.
- the upper flange 4 which is also formed of a synthetic resin material, is affixed to the reel hub 2 by ultrasonic welding with the upper flange 4 being fitted to the top end of the reel hub 2 .
- the reel hub 2 and the lower flange 3 may be integrally formed of a material which is a polycarbonate resin containing 10% of carbon fibers, while the upper flange 4 may be formed of only a polycarbonate resin.
- the lower portion of the reel hub 2 is closed by a bottom wall 2 a, and a crown gear type reel gear 5 , which is meshable with a driving gear (not shown) of a rotary driving member in a drive device (hereinafter referred to as the drive-side rotary driving member), is provided in an annular form at an outer peripheral portion of a lower surface of the bottom wall 2 a.
- a metal plate 6 is attached to the lower surface of the bottom wall 2 a of the reel hub 2 within the reel gear 5 by insert molding. The metal plate 6 is provided because the metal plate 6 is magnetically attracted with respect to the drive-side rotary driving member, thus keeping the meshed state between the reel gear 5 and the driving gear.
- a plurality of interlocking protrusions 7 are formed integrally with the reel hub 2 on the upper surface of the bottom wall 2 a so as to be circumferentially disposed at equal spaces from one another.
- a locking member (not shown) having lock teeth, which are to be brought into mesh with lock teeth 7 a, serves to block the rotation of the reel 1 .
- the thickness t of the peripheral wall of the reel hub 2 and the thickness t′ of the lower flange which is integrally molded with the reel hub 2 are selected such that thickness t′ falls within ⁇ 20% of the thickness t. That is, the thickness t and the thickness t′ are selected to satisfy the relationship given by 0.8t ⁇ t′ ⁇ 1.2t.
- the thickness t′ of the lower flange 3 is selected to be greater than the thickness t of the peripheral wall of the reel hub 2 such that the relationship 0.8t ⁇ t′ ⁇ 1t is satisfied.
- the thickness t of the peripheral wall of the reel hub 2 and the thickness t′ of the lower flange 3 are selected to satisfy the relationship described above. Therefore, a difference in fluidity during molding is reduced, forming of the reel is facilitated, and it becomes possible to reduce the deviation in height at the radially outer end of the lower flange 3 from the reference level while maintaining appropriate cylindricity and strength of the reel hub 2 .
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- Storage Of Web-Like Or Filamentary Materials (AREA)
Abstract
Description
- 1. Field of the Invention
- The present invention relates to a magnetic tape reel formed of a synthetic resin material.
- 2. Description of the Related Art
- Conventionally, as magnetic tape cartridges that are used as storage media for an external storage unit of computers and the like, there have been known those having a cartridge case which rotatably houses a single reel with a magnetic tape being wound around the reel.
- As described, for example, in Japanese Unexamined Patent Publication No. 2002-352551, magnetic tape cartridges of this type generally have a single reel which is housed in a cartridge case in a rotatable manner. This single reel comprises a resin reel hub around which a magnetic tape is wound, and upper and lower flanges respectively extending radially outward from the outer peripheries of the upper and lower ends of the reel hub.
- In this case, the reel hub and the lower flange are typically integrally molded of a synthetic resin material. The upper flange, which is also formed of the same or another synthetic resin material, is fixed to the reel hub by ultrasonic welding with the upper flange being fitted to a top end of the reel hub.
- With the recent tendency of increasing data storage capacity, longer magnetic tapes have come to be used, thereby increasing a tightening force of magnetic tapes and hence deforming reel hubs. However, this results in contact between reel flanges and magnetic tapes and hence poses a problem that tape edges of the magnetic tapes are damaged.
- In order to prevent the deformation of the reel hub, enhancement of the strength of the reel hub by incorporating fillers like carbon fibers into the synthetic resin material of which the reel hub is formed, has been proposed. Not only from a viewpoint of enhancing the strength of the reel, but also from a viewpoint of preventing the electrification on the reel surface, a carbon fiber is desirable filler.
- However, the thermal conductivity of a polycarbonate resin and the thermal conductivity of a resin material which is a polycarbonate resin containing 10% of glass fibers are respectively 0.2 W/(m·K) and 0.23 W/(m·K), whereas the thermal conductivity of a resin material which is a polycarbonate resin containing 10% of carbon fibers is 0.45 W/(m·K), or as much as approximately twice those of the polycarbonate resin and the resin material containing 10% of glass fibers. Thus, the curing time during molding is relatively short, whereby the resin material becomes difficult to flow to a cavity portion located far from a gate of a molding die.
- Meanwhile, the thickness of the flange of reel is typically as low as half the thickness of the peripheral wall of the reel hub, and the radially outer end of the flange is remote from the gate of the molding die. Accordingly, when a resin material in which carbon fibers are incorporated is used, the difficulty of flowing of the resin material to the radially outer end of the flange causes a larger deviation in height at the radially outer end of the flange from a reference level. Further, a difference in fluidity caused between the flange portion and the reel hub portion brings a new problem that controlling of the molding conditions is difficult.
- In view of the foregoing, an object of the present invention is to reduce the aforementioned difference in fluidity during molding when the resin material in which carbon fibers are incorporated is used to enhance the strength of the reel, and hence to facilitate the controlling of the molding conditions.
- According to the present invention, there is provided a magnetic tape reel comprising a cylindrical reel hub around which a magnetic tape is wound; and upper and lower flanges respectively extending radially outward from outer peripheries of upper and lower ends of the reel hub, wherein when the reel hub and one of the upper and lower flanges are integrally molded of a synthetic resin material containing carbon fibers, a thickness t of a peripheral wall of the reel hub and a thickness t′ of one of the flanges to be integrally molded with the reel hub are selected to satisfy the relationship given by 0.8t≦t′≦1.2t.
- More preferably, the thickness t of the peripheral wall of the reel hub and the thickness t′ of one of the flanges are selected to satisfy the relationship given by 0.8t≦t′≦1t. The aforementioned synthetic resin material is preferably a polycarbonate resin containing at least 5% of carbonate fibers.
- In this way, when the reel hub and one of the upper and lower flanges are integrally molded of a synthetic resin material (for example, a polycarbonate resin) containing carbon fibers, a greater thickness t′ of the flange results in better fluidity. However, increasing the thickness t′ of the flange and hence reducing the ratio t/t′ of the thickness t of the peripheral wall of the reel hub to the thickness t′ results in deterioration of the cylindricity of the reel hub although the deviation in height at the radially outer end of the flange from the reference level during molding is reduced. In contrast, increasing the thickness t of the peripheral wall of the reel hub and hence increasing the ratio t/t′ results in increasing of the deviation in height at the radially outer end of the flange from the reference level although the cylindricity of the hub is improved and the strength of the reel hub is enhanced.
- According to the present invention, the thickness t′ of the flange which is integrally molded with the reel hub is selected to fall within ±20% of the thickness t of the peripheral wall of the reel hub, whereby the controlling of the molding conditions is facilitated, and it becomes possible to reduce the deviation in height at the radially outer end of the flange from the reference level while maintaining appropriate cylindricity and strength of the reel hub.
- Since a flowing distance of the resin material to the flange is longer than that to the reel hub during molding, it is preferred that the relationship t≦t′ is satisfied.
- FIGURE shows a longitudinal sectional view of a magnetic tape reel according to one embodiment of the invention.
- Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawing. FIGURE is a longitudinal sectional view of an inventive reel to be incorporated in a magnetic tape cartridge.
- Referring to FIGURE, a
reel 1 to be rotatably housed within a case of a magnetic tape cartridge (not shown) comprises: areel hub 2 which is shaped in the form of a tubular member with an outer diameter of about 40 mm, a closed bottom and an open top, and around which a magnetic tape is wound; and lower andupper flanges reel hub 2. Thereel hub 2 and thelower flange 3 are integrally molded of a synthetic resin material. Theupper flange 4, which is also formed of a synthetic resin material, is affixed to thereel hub 2 by ultrasonic welding with theupper flange 4 being fitted to the top end of thereel hub 2. For example, thereel hub 2 and thelower flange 3 may be integrally formed of a material which is a polycarbonate resin containing 10% of carbon fibers, while theupper flange 4 may be formed of only a polycarbonate resin. - The lower portion of the
reel hub 2 is closed by abottom wall 2 a, and a crown geartype reel gear 5, which is meshable with a driving gear (not shown) of a rotary driving member in a drive device (hereinafter referred to as the drive-side rotary driving member), is provided in an annular form at an outer peripheral portion of a lower surface of thebottom wall 2 a. Further, ametal plate 6 is attached to the lower surface of thebottom wall 2 a of thereel hub 2 within thereel gear 5 by insert molding. Themetal plate 6 is provided because themetal plate 6 is magnetically attracted with respect to the drive-side rotary driving member, thus keeping the meshed state between thereel gear 5 and the driving gear. - A plurality of interlocking
protrusions 7, each having alock tooth 7 a at its extremity, are formed integrally with thereel hub 2 on the upper surface of thebottom wall 2 a so as to be circumferentially disposed at equal spaces from one another. When the magnetic tape cartridge is in the non-operating state, a locking member (not shown) having lock teeth, which are to be brought into mesh withlock teeth 7 a, serves to block the rotation of thereel 1. - In such an arrangement, the thickness t of the peripheral wall of the
reel hub 2 and the thickness t′ of the lower flange which is integrally molded with thereel hub 2 are selected such that thickness t′ falls within ±20% of the thickness t. That is, the thickness t and the thickness t′ are selected to satisfy the relationship given by 0.8t≦t′≦1.2t. - In addition, since a flowing distance of the resin material to the
lower flange 3 during molding is longer than that to thereel hub 2, it is more preferable that the thickness t′ of thelower flange 3 is selected to be greater than the thickness t of the peripheral wall of thereel hub 2 such that the relationship 0.8t≦t′≦1t is satisfied. - As is apparent from the above description, according to the embodiment of the invention, the thickness t of the peripheral wall of the
reel hub 2 and the thickness t′ of thelower flange 3 are selected to satisfy the relationship described above. Therefore, a difference in fluidity during molding is reduced, forming of the reel is facilitated, and it becomes possible to reduce the deviation in height at the radially outer end of thelower flange 3 from the reference level while maintaining appropriate cylindricity and strength of thereel hub 2.
Claims (4)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004072630A JP2005259304A (en) | 2004-03-15 | 2004-03-15 | Reel for magnetic tape |
JP072630/2004 | 2004-03-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20050199765A1 true US20050199765A1 (en) | 2005-09-15 |
Family
ID=34918617
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/079,217 Abandoned US20050199765A1 (en) | 2004-03-15 | 2005-03-15 | Magnetic tape reel |
Country Status (2)
Country | Link |
---|---|
US (1) | US20050199765A1 (en) |
JP (1) | JP2005259304A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106315313A (en) * | 2016-08-30 | 2017-01-11 | 岳阳凯立信电气有限公司 | Novel vehicle-mounted cable drum |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4891881B2 (en) * | 2007-10-23 | 2012-03-07 | パナソニック株式会社 | cartridge |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040170717A1 (en) * | 2002-12-03 | 2004-09-02 | Tdk Corporation | Molding mold, molding method and tape cartridge |
US7104486B2 (en) * | 2003-12-29 | 2006-09-12 | Fuji Photo Film Co., Ltd. | Recording tape cartridge |
-
2004
- 2004-03-15 JP JP2004072630A patent/JP2005259304A/en not_active Abandoned
-
2005
- 2005-03-15 US US11/079,217 patent/US20050199765A1/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040170717A1 (en) * | 2002-12-03 | 2004-09-02 | Tdk Corporation | Molding mold, molding method and tape cartridge |
US7104486B2 (en) * | 2003-12-29 | 2006-09-12 | Fuji Photo Film Co., Ltd. | Recording tape cartridge |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106315313A (en) * | 2016-08-30 | 2017-01-11 | 岳阳凯立信电气有限公司 | Novel vehicle-mounted cable drum |
Also Published As
Publication number | Publication date |
---|---|
JP2005259304A (en) | 2005-09-22 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: FUJI PHOTO FILM CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ASANO, KATSUKI;REEL/FRAME:016387/0271 Effective date: 20050301 |
|
AS | Assignment |
Owner name: FUJIFILM CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.);REEL/FRAME:018904/0001 Effective date: 20070130 Owner name: FUJIFILM CORPORATION,JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.);REEL/FRAME:018904/0001 Effective date: 20070130 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |