Patent Application
20070102563
1. Field of the Invention
The present invention relates to a method and apparatus for producing a magnetic tape cartridge, and, more particularly, to a method and apparatus for winding an electromagnetic tape on a tape reel with its side edge leaned on a base flange as desired.
2. Description of Related Art
Magnetic tapes are extensively used in magnetic tape cartridges as data backup recording medium for computers. Such a magnetic tape cartridge is known in two types, one having a single tape reel and the other having a pair of tape reels. In a general way, the magnetic tape cartridge is prepared by guiding and feeding a magnetic tape reeled out from a supply reel in a cartridge casing and winding it around a core hub of a tape reel in the cartridge casing with its side edge leaned on a base flange of the reel.
There has been proposed air guide devices for guiding a magnetic tape in non-contact with it such as described in, for example, Unexamined Japanese Patent Publication Nos. 2002-117598 and 2004-110953. Such an air guide device comprises a cylindrical air guide barrel having a number of air holes through which air is discharged against the magnetic tape. Either air guide means is configured to guide a magnetic tape controlling it in posture and position so as to be in parallel with an axis of the cylindrical air guide barrel in a width direction of tape and to feed the magnetic tape in the a cartridge casing so as to be in parallel with an axis of the core hub of the tape reel.
However, according to the study findings by the inventors of this application, it has been proved that the prior art air guide makes it hard to wind a magnetic tape around the core hub with its side edge leaned on a base flange of the reel.
It is therefore an object of the present invention to provide a method and apparatus for producing a magnetic tape cartridge in which a magnetic tape is always wound with its side edge leaned on a base reel flange.
The foregoing object of the present invention is accomplished by a method for producing a magnetic tape cartridge by winding a magnetic tape around a tape reel having a reel hub and reel flanges secured to the reel hub which is installed in a cartridge shell housing, which comprises the steps of feeding a magnetic tape toward the tape reel, tilting down the magnetic tape in a transverse direction of the magnetic tape while guiding the magnetic tape in non-contact with the magnetic tape within a specified guide area in a longitudinal direction of the magnetic tape by air guide means, and winding the magnetic tape on the reel hub with a downside edge of the magnetic tape leaned on a specified one of the reel flanges, namely a base flange. The air guide means blows air against the magnetic tape in a specified pressure distribution pattern in which pressure is lower on the downside edge than on an opposite side edge in the transverse direction.
According to the present invention, a magnetic tape is biased by air so as to be tilted down in a transverse direction while guided in non-contact with the guide means within the specified guide area in the longitudinal direction prior to being wound on the reel hub. In consequence, the magnetic tap is wound with the downside edge thereof leaned on the base flange.
The pressure distribution pattern is such that pressures decrease gradually in the transverse direction in proportion as getting closer to the downside edge of the magnetic tape. Further, the pressure distribution pattern is desirably such that pressures increase gradually in proportion as getting closer to extreme ends of the specified guide area in the circumferential direction.
Tilting down of the magnetic tape in the transverse direction is performed by means of an uneven distribution of air pressure which is provided by air guide means. Specifically, the air guide means comprises air blowing means for blowing pressurize air against the magnetic tape in a specified pressure distribution pattern in which pressure is lower on the downside edge than on an opposite side edge in the transverse direction. The air blowing means may comprise an air supply source for supplying pressurized air and a cylindrical tape guide barrel disposed in a path of the magnetic tape with a center axis put in parallel with an axis of rotation of the tape reel for forming an air chamber therein for receiving the pressurized air. The cylindrical tape guide barrel is provided with a number of air discharge orifices formed in the barrel wall through which the pressurized air introduced in the air chamber is blown against the magnetic tape in the specified pressure distribution pattern. With the air blow, the magnetic tape is paced from the cylindrical tape guide barrel and tiled down in a transverse direction of the magnetic tape. The air discharge orifices are distributed in axial and circumferential directions in various forms. For example, the air discharge orifices in the axial direction may be made smaller in diameter on a base side of the cylindrical tape guide barrel which is on the same side as the specified reel flange than at the middle of the specified guide area in the axial direction, or decrease gradually smaller in diameter as getting on toward a base side of the cylindrical tape guide barrel which is on the same side as the specified reel flange. Further, the air discharge orifices may be distributed in a distribution pattern in which a density of distribution is lower on a base side of the cylindrical tape guide barrel which is on the same side as the specified reel flange than at the middle of the specified guide area in the axial direction, or in a distribution pattern in which a density of distribution decrease gradually lower as getting on toward a base side of the cylindrical tape guide barrel which is on the same side as the specified reel flange. The air discharge orifices may further distributed in various pattern in the circumferential direction. Specifically, the air discharge orifices in the circumferential direction may be made larger in diameter on opposite extreme ends of the specified guide area in the circumferential direction than at the middle of the specified guide area in the circumferential direction, or may increase gradually larger in diameter as getting on toward an extreme end of the specified guide area. Further, the air discharge orifices may be distributed so that a density of distribution is higher on opposite extreme ends of the specified guide area in the circumferential direction than at the middle of the specified guide area, or so that a density of distribution increases gradually higher as getting on toward an extreme end of the specified guide area in the circumferential direction.
Although, according to the prior art air guide device in which the air discharge orifices have the same diameters and are evenly distributed in a direction of tape feed, pressures of air blowing against a magnetic tape decrease gradually in proportion as getting closer to opposite extreme ends of the overlap area between the magnetic tape and the tape guide barrel in the direction of tape feed. As a result, according to circumstances, the space between the magnetic tape and the tape guide barrel decreases gradually as getting closer to the opposite extreme ends of the overlap area, so that it is feared in such an event that the magnetic tape possibly comes in contact with the tape guide barrel near the boundaries on the base side. However, according to the present invention, the magnetic tape is kept at an almost equal distance from the tape guide barrel due to the uneven pressure distribution in the direction of tape feed while passing through the overlap area.
The foregoing and other objects and features of the present invention will be clearly understood from the following detailed description when reading with reference to the accompanying drawings wherein same or similar parts or mechanisms are denoted by the same reference numerals throughout the drawings and in which:
Referring to the accompanying drawings in detail, and in particular, to
The tape feeding device 10 includes tape reels 11a and 11b on which the magnetic tapes 2 are wound and which are interchangeably driven at a specified rotational speed to reel out the magnetic tape 2. While one of the tape reels 11a and 11b is out of service, another magnetic tape is prepared on it for another service. Therefore, magnetic tape 2 is continuously fed toward the tape winding device 20. The magnetic tape 2 reeled out from the tape reel 11a or 11b is subjected to surface polish by the polishing device 30 and to removal of tape dust and foreign particles from both surface of the magnetic tape 2 by the cleaning devices 40, and then sent to the air guide device 90. On the way, the magnet tape 2 is appropriately tensioned by the tension controlling device 50.
Referring to
Referring to
Air introduced into the air chamber 111c of the tape guide barrel 111 blasts out through the air discharge orifices 111b to blow against the magnetic tape 2 traveling over the tape guide barrel 111 so as thereby to space the magnetic tape 2 from the tape guide barrel 111 traveling toward the tape winding device 20. In other words, the magnetic tape 2 is guided by the air guide device 90 so as to travel over the same in non-contact with the tape guide barrel 111. At this time, pressures of the air blowing against the magnetic tape 2 gradually increase in proportion as getting away further from the base side 111d of the tape guide barrel 111, so that the magnetic tape 2 is tilted down on the base side 111d of the tape guide barrel 111 as shown in
The tape winding device 20 includes the cartridge holding and positioning device 21 for holding the magnetic tape cartridge 3 supplied from the cartridge feed device 60 in a specified position with an axis of rotation of the tape reel 4 put in a horizontal position and the tape traction device 22 for carrying a leading end of the magnetic tape 2 into the cartridge shell housing 5 of the magnetic tape cartridge 3 held in position by the cartridge holding and positioning device 21. The tape traction device 22 is operated by, for example, a pneumatic drive system to move between a standby position outside the cartridge holding and positioning device 21 and a working position in the cartridge holding and positioning device 21. The tape traction device 22 is provided with suction holding means (not shown) for holding a leading end of the magnetic tape 2 in the standby position and presses it against the reel hub 4a of the tape reel 4 in the working position.
In operation of the magnetic tape winding apparatus 1, when the magnetic tape winding apparatus 1 is activated, either one of the tape reels 11a and 11b is driven to reel out the magnetic tape 2 at a specified rate. The magnetic tape 2 from the tape reel 11a or 11b is guided in the path by the guide rollers 80 toward the tape traction device 22. During traveling to the tape traction device 22, the magnetic tape 2 is polished by the polishing device 30 and cleaned by the cleaning devices 40. The magnetic tape 2 is controlled by the tension controlling device 50 so as to travel under proper tension. Until the magnetic tape 2 reaches the tape traction device 22, the air pump for supplying air to the air guide device 90 is under suspension Therefore, the magnetic tape 2 travels forward being guided between inclined wall surfaces of the frustum-shaped top end 110a of the cylindrical solid base pillar 110 and the frustum-shaped under side wall 112 of the top retainer disk 112. When the tape traction device 22 in the standby position is reached by the leading end of the magnetic tape 2, while the tape traction device 22 is activated to hold the magnetic tape 2 by suction, the tape winding device 20 is activated to rotate the tape reel 4 of the magnetic tape cartridge 3 held in position by the cartridge holding and positioning device 21 at a specified speed of rotation. The magnetic tape winding apparatus 1 is adapted to control the tape reels 11a, 11b and 4 so that a reel out rate of the tape reel 11a or 11b and a winding rate of the tape reel 4 match well with each other. Once the tape traction device 22 moves to the working position and presses the magnetic tape 2 against the reel hub 4a of the tape reel 4 which is rotating a the specified speed of rotation, the tape traction device 22 is deactivated and return to the standby position. At the same time, the magnetic tape 2 is wound around the reel hub 4a. When the magnetic tape 2 is wound around the reel hub 4a at least one or two turns, the magnetic tape 2 encounters a momentary increase in tension. The magnetic tape winding apparatus 1 detects the momentary increase in tension to activate the air pump of the air guide device 90, more specifically the air pump of the air guide device 90, and controls rotation of the tape reels 4 and 11a or 11b so as to balance the reel out rate and the winding rate. Once the magnetic tape 2 coils around the reel hub 2, the air pump of the air guide device 90 is activated to supply pressurized air into the air chamber 111c. In consequence, the air blasts out through the air discharge orifices 111b of the tape guide barrel 111 to blow against the magnetic tape 2 and spaces it from the tape guide barrel 111. That is, the magnetic tape 2 is tilted down in a transverse direction. In this way, while traveling forward to the tape reel 4, the magnetic tape 2 is always biased toward the base side 111d of the tape guide barrel 111 and, in natural consequence, against the base flange 4b of the tape reel 4 as shown in
In the case where the air discharge orifices 111b have the same diameters and are evenly distributed in the direction of tape feed C, pressures of air blowing against the magnetic tape 2 gradually increase in proportion as getting closer to the opposite extreme ends of the overlap area between the magnetic tape 2 and the tape guide barrel 111 in the direction of tape feed C. As a result, the space between the magnetic tape 2 and the tape guide barrel 111 gradually decreases as getting closer to the opposite extreme ends of the overlap area, so that it is feared that the magnetic tape 2 at the side edge possibly comes in contact with the tape guide barrel 111 near the boundaries on the base side. However, with the air guide device 90, the magnetic tape 2 is kept at an almost equal distance from the tape guide barrel 111 due to the uneven pressure distribution in the direction of tape feed C while passing through the overlap area. Nevertheless, it is not always essential to distribute the air discharge orifice 111b so as to increase pressures higher as getting on toward opposite extreme ends of the overlap area in the direction of tape feed C.
It is a matter of course that variants of air discharge orifice distribution pattern which brings about the same effect of pressure distribution as those described above may occur to those skilled in the art
It is also to be understood that although the present invention has been described with regard to preferred embodiments thereof, various other embodiments and variants may occur to those skilled in the art, which are within the scope and spirit of the invention, and such other embodiments and variants are intended to be covered by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-325648 | Nov 2005 | JP | national |
