Patent Application
20120017935
This invention relates to magnetic tape drives, and more particularly to magnetic tape heads which read and write data with respect to a movable magnetic tape.
Magnetic tape drives function to read and write data with respect to magnetic tape, employing at least one magnetic tape head to read and write data as magnetic tape is moved in a longitudinal direction of the tape and across the read/write surface of the head. The operating performance of the magnetic tape drive can be adversely affected by the build up of tape debris at the tape-head interface. In addition to the common tape debris, polyethylene smears may build up on the head and result in the separation of the tape from the head, adversely affecting the reading and writing of data to and from the tape. Fibrous brushes have been employed with the desire of brushing debris from the tape head.
A magnetic tape head cleaners and cleaning methods are provided for a magnetic tape head having at least one read/write surface, wherein the magnetic tape head is configured to read and write data with respect to a movable magnetic tape as the tape is moved in a longitudinal direction of the tape and across the read/write surface(s) of the head.
In one embodiment, a magnetic tape head cleaner comprises:
a closed cellular polyurethane foam pad; and
a support member configured to support the pad for movement of the pad across and in contact with the read/write surface(s) of the magnetic tape head.
In a further embodiment, the closed cellular polyurethane foam pad comprises a Shore hardness of substantially 55-60.
In another embodiment, the closed cellular polyurethane foam pad comprises a density of 1.0 to 0.15 g/cm3, and in a further embodiment, the closed cellular polyurethane foam pad comprises a density of substantially 0.5 to 0.3 g/cm3.
In yet another embodiment, the closed cellular polyurethane foam pad additionally comprises an abrasive particle filler having a concentration of 10 to 0.01 percentage by weight, and in a further embodiment, the closed cellular polyurethane foam pad abrasive particle filler comprises a concentration of substantially 3 to 0.5 percentage by weight.
In a still further embodiment, the abrasive particle filler is one of Alumina and Titanium oxide.
In another embodiment, the closed cellular polyurethane foam pad additionally is impregnated with a carbon based conductive filler having a concentration of 15 to 0.01 percentage by weight, and in a further embodiment, the closed cellular polyurethane foam pad is impregnated with the carbon based conductive filler to a concentration of substantially 5 to 0.5 percentage by weight.
Another embodiment of a magnetic tape head cleaner for a magnetic tape head comprises an interior reinforcing layer; and a closed cellular polyurethane foam pad overlaying the interior reinforcing layer on at least all surfaces that are arranged to contact the read/write surface(s) of the magnetic tape head.
An embodiment of a method for cleaning a magnetic tape head having at least one read/write surface comprises moving a closed cellular polyurethane foam pad comprising a Shore hardness of substantially 55-60 and comprising a density of 1.0 to 0.15 g/cm3 across and in contact with the read/write surface(s) of the magnetic tape head.
For a fuller understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.
This invention is described in preferred embodiments in the following description with reference to the Figures, in which like numbers represent the same or similar elements. While this invention is described in terms of the best mode for achieving this invention's objectives, it will be appreciated by those skilled in the art that variations may be accomplished in view of these teachings without deviating from the spirit or scope of the invention.
Referring to
Referring additionally to
Embodiments of the closed cellular polyurethane foam pad 10 are illustrated in
The embodiment of pad 10 of both
The embodiment of pad 10 of
Referring to
In another embodiment, the closed cellular polyurethane foam pad 10 additionally comprises an abrasive particle filler having a concentration of 10 to 0.01 percentage by weight, and preferably from 5 to 0.1 percentage by weight, and in a further embodiment, the closed cellular polyurethane foam pad abrasive particle filler comprises a concentration of substantially 3 to 0.5 percentage by weight. In one embodiment, the abrasive particle filler is one of Alumina and Titanium oxide. An advantage of the abrasive particle filler is to increase the level of abrasion by the pad 10.
In another embodiment, the closed cellular polyurethane foam pad 10 additionally is impregnated with a carbon based conductive filler having a concentration of 15 to 0.01 percentage by weight, and preferably 10 to 0.1 percentage by weight, and in a further embodiment, the closed cellular polyurethane foam pad is impregnated with the carbon based conductive filler to a concentration of substantially 5 to 0.5 percentage by weight. Examples of carbon based conductive fillers comprise carbon black, graphite, and carbon nanotubes (single and multi-walled). An advantage of the carbon based conductive filler is to provide ESD (electrical static discharge) protection to the magnetic tape head.
The closed cellular polyurethane foam pad 10 is preferably employed without a solvent, and may therefore be called “solventless”.
The magnetic tape media 11 is moved in the longitudinal direction of the tape and across the magnetic tape head 65. The tape head may be supported and laterally moved by a compound actuator 17 of a track following servo system. The magnetic tape media is supported by roller tape guides 50, 51, 52, 53 while the magnetic tape media is moved longitudinally.
A typical magnetic tape data storage drive operates in both the forward and reverse directions to read and write data. Thus, the magnetic tape head 65 may comprise one set of read and write elements for operating in the forward direction and another set for operating in the reverse direction, or alternatively, may have two sets of the read elements on either side of the write elements to allow the same write elements to write in both directions while the two sets of read elements allow a read-after-write in both directions.
The magnetic tape data storage drive 90 comprises one or more controls 20 for operating the magnetic tape data storage drive in accordance with commands received from an external system. The external system may comprise a network, a host system, a data storage library or automation system, a data storage subsystem, etc., as is known to those of skill in the art. A control typically comprises logic and/or one or more microprocessors with a memory for storing information and program information for operating the microprocessor(s) and drive. The program information may be supplied to the memory via an interface, by an input to the control 20 such as a floppy or optical disk, or by reading from a magnetic tape cartridge, or by any other suitable means. The magnetic tape data storage drive 10 may comprise a standalone unit or comprise a part of a tape library or other subsystem, which may comprise the external system. The control 20 also provides the data flow and formatter for data to be read from and written to the magnetic tape media, as is known to those of skill in the art.
The magnetic tape drive 90 is configured to receive a magnetic tape cartridge 13 oriented in a single direction, and to engage and move the cartridge into a specified position in the cartridge receiver. A tape threading mechanism moves the free end of the magnetic tape 11 from the magnetic tape cartridge 13 to a take up reel 14, for example, positioning the free end leader block at the central axis of the take up reel. The magnetic tape is thus positioned along the tape path. Before the tape is threaded into the magnetic tape drive, the control 20 operates the support member 18 to move the closed cellular polyurethane foam pad 10 across and in contact with the read/write surface(s) of the magnetic tape head 65. Referring additionally to
Referring additionally to
Alternative arrangements of mechanisms to move the support member 18, to thereby move closed cellular polyurethane foam pad 10 across and in contact with the read/write surface(s) of the magnetic tape head 65 may be envisioned by those of skill in the art.
The implementations of control 20 may involve software, firmware, micro-code, hardware and/or any combination thereof. The implementation may take the form of code or logic implemented in a medium, where the medium may comprise hardware logic (e.g. an integrated circuit chip, Programmable Gate Array [PGA], Application Specific Integrated Circuit [ASIC], or other circuit, logic or device), or a computer readable storage medium, such as a magnetic storage medium (e.g. an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, semiconductor or solid state memory, magnetic tape, a removable computer diskette, and random access memory [RAM], a read-only memory [ROM], a rigid magnetic disk and an optical disk, compact disk-read only memory [CD-ROM], compact disk-read/write [CD-R/W] and DVD).
Those of skill in the art will understand that changes may be made with respect to the methods discussed above, including changes to the ordering or direction of motion of the steps. Further, those of skill in the art will understand that differing specific component arrangements may be employed than those illustrated herein.
While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims.
