Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Including threading
Reexamination Certificate
2000-03-31
2001-11-06
Rivera, William A. (Department: 3653)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Including threading
C242S587100, C242S348200
Reexamination Certificate
active
06311916
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a leader block assembly for a data storage tape cartridge. More particularly, it relates to a leader block configured for preventing leader block impressions on data storage tapes.
Data storage tape cartridges have been used for decades in the computer, audio, and video fields. The data storage tape cartridge continues to be an extremely popular form of recording large volumes of information for subsequent retrieval and use.
A data storage tape cartridge generally consists of an outer shell or a housing maintaining at least one tape reel assembly and a length of magnetic storage tape. The storage tape is wrapped about a hub portion of the tape reel and is driven through a defined tape path by a driving system. The housing normally includes a separate cover and a base, the combination of which forms an opening (or window) at a forward portion thereof for allowing access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into a tape drive.
In a reel-to-reel magnetic tape drive, a free end of the storage tape is directed away from the housing of the data tape cartridge to an adjacent area at which the read/write head is located. The free end of the storage tape of the data tape cartridge is typically secured to a leader block for assisting guidance of the storage tape. In particular, the leader block is removably inserted into a drive take-up reel (separate from the data storage tape cartridge) and the storage tape from the cartridge is wound about the drive take-up reel as data is accessed/recorded from the tape by the adjacent read/write head.
As shown in
FIGS. 1-2
, a conventional leader block
10
includes a generally rectangular body
12
defining a trailing end
14
and a leading end
16
. The trailing end
14
terminates in an end surface
18
. Prior art leader block
10
further includes opposite sides
20
and edges
21
with T-shaped protrusions
22
configured for reciprocally engaging a slot of a drive take up reel to removably secure the leader block
10
relative to the drive take-up reel.
As shown in
FIG. 3
, a conventional drive take-up reel
30
includes a ringshaped hub
32
and opposing flanges
34
. The hub
32
defines a tape-winding surface
36
, about which the storage tape (not shown) is wound, and a slot
38
. The slot
38
is adapted for receiving the leader block
10
. The flanges
34
define a pair of notches
40
contiguous with the edges of the slot
38
for receiving the protrusions
22
of the leader block
10
. As further shown in
FIG. 4
, the slot
38
is defined by opposing sidewalls
41
, while the notch
40
of each flange
34
further includes a shelf
42
and a channel
44
.
During use, the leader block
10
is inserted into the slot
38
of the drive take-up reel
30
, with the opposite sides
20
of the leader block
10
being slidingly received by sidewalls
41
of the slot
38
of the take-up reel
30
. Upon further insertion of the leader block
10
, the T-shaped protrusions
22
are supported by the shelf
42
of the notches
40
to resist further sliding movement of leader block
10
radially inward relative to the slot
38
. This interaction attempts to maintain the end surface
18
of the leader block
10
in a generally flush relationship with the tape-winding surface
36
of the drive take-up reel
30
. Accordingly, all of the radial support for the leader block
10
occurs at the notches
40
of the flanges
34
at the edges of hub
32
(see FIG.
3
).
Following insertion, the data storage tape (not shown) is wound about the hub
32
. In theory, a radius of the end surface
18
of the leader block
10
“matches” a radius of the hub
32
. However, as the amount of wrapped tape increases, a substantial pressure is exerted radially inward on the leader block
10
, causing a significant middle portion of the end surface
18
to bow or sag radially inward relative to the tape-winding surface
36
. This sagging occurs because the notches
40
provide relatively little radial support for the leader block
10
. This sagging results in a mismatch or a gap between the end surface
18
of the leader block
10
and the tape-winding surface
36
. As the data storage tape is further wound about the hub
32
, the storage tape is forced into or fills the gap, creating impressions in the storage tape (or “leader block impressions”). These leader block impressions may reduce the storage capacity of the data storage tape, and possibly permanently damage the storage tape.
The ability of a leader block to remain properly seated into a drive takeup reel has a very large affect on likelihood of the leader block impressions and their transfer through the storage tape. If these leader block impressions are severe, they will transmit through many feet of tape, reducing the data transfer and storage capacity of the cartridge. Currently, to overcome the problem of leader block impressions, more tape is added to the data tape cartridge and drive software is programmed to move the start of data transfer away from the beginning of the tape (at which leader block impressions are most prevalent). Advancements in storage tape media have resulted in highly thin tape.
The decreased thickness tape is even more susceptible to any winding surface mismatch and the ensuing leader block impressions that transfer through the tape wound on the drive take-up reel. Accordingly, the longstanding problem of leader block impressions in data storage tape threatens to nullify the gains obtained by recently available, thinner storage tapes. Moreover, the problem of leader block impressions still requires remedial adjustments such as software changes and intentionally not using portions of the data storage tape.
Data storage tape cartridges are important tools used to maintain vast amounts of information. To remain competitive, data storage tape cartridge manufacturers must continually improve cartridge performance while reducing manufacturing costs. Solving leader block impressions in data storage tapes remains a challenge.
SUMMARY OF THE INVENTION
One aspect of the present invention provides a leader block assembly for holding a length of data storage tape and for use with a tape drive take-up reel. The leader block assembly includes a generally rectangular body having opposing sides, a leading end, a trailing end terminating in an end surface, and first and second ears. The cars are formed at the trailing end and extend radially relative to the sides along at least a substantial portion of a width of the trailing end. More particularly, the ears are configured to substantially prevent longitudinal sliding movement of the end surface upon insertion of the leader block assembly into a drive take-up reel. In a preferred embodiment, each of the ears forms a transverse contact surface configured to engage a corresponding surface associated with a take-up reel. The transverse contact surfaces each define a length preferably approximating a width of the trailing end. During use, the leader block assembly, and in particular, the end surface is supported by the ears along at least a substantial portion of the width of the trailing end.
Another aspect of the present invention relates to a data storage tape cartridge. The data storage tape cartridge includes a housing, at least one tape reel, a storage tape, and a leader block assembly. The housing defines an enclosure. The tape reel is disposed within the enclosure and includes a hub and opposing flanges. The storage tape is wound about the hub. Finally, the leader block assembly is secured to a free end of the storage tape. The leader block assembly includes a generally rectangular body having opposing sides, a leading end, a trailing end terminating in an end surface, and first and second cars. The cars are formed at the trailing end and extend radially relative to the sides along a substantial portion of a width of the trailing end. With this in mind, the ears are configured to substantially prevent longitudinal sliding movement of
Johnson Michael W.
Rambosek G. Phillip
Imation Corp.
Levinson Eric D.
Rivera William A.
LandOfFree
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