Method of force/acceleration reel tape sizing
AssigneeInternational Business Machines Corporation
InventorsKenneth D. Danielsen, Daniel J. Winarski
Life of this patent
Estimating the term…
Abstract
The amount of tape wound on the hub of a reel can be determined by the tape drive by using a force/acceleration relationship. An electrical power which provides a certain torque to the motor is applied to the reel drive. The torque imparts a fixed rotational displacement over a fixed period of time. The rotational displacement is measured by a tachometer. The angular acceleration of different inertias results in different rotational displacement over the set period of time which can be used to indicate the amount of tape on the reel since the inertia of the other items, the motor, the clutch and the hub, remains the same.
Claims30
In a magnetic tape drive, a method of checking the amount of tape wound on a hub of a reel comprising the steps of:
- holding the free end of the tape wound on the hub;
- rotating the hub in a direction to wind the tape;
- rotating the hub for a predetermined period of time with a predetermined torque in a direction to unwind the tape from the hub;
- determining the rotational distance traveled by the rotated hub in the unwind direction for the set period of time;
- and
- indicating the amount of tape on the hub as a result of the determined rotational distance traveled for the set period of time due to the inertia of the tape and associated parts.
In a magnetic tape drive, a method for checking the length of tape wound on the hub of a reel comprising the steps of:
- inserting the reel containing the tape into the drive;
- holding the free end of the tape wound on the hub;
- rotating the hub in a direction to wind the tape;
- rotating the hub for a predetermined period of time with a predetermined torque in a direction to unwind the tape from the hub;
- determining the rotational distance traveled by the rotated hub in the unwind direction for the set period of time;
- and
- indicating the amount of tape on the hub as a result of the determined rotational distance traveled due to the inertia of the tape and the associated parts.
In a magnetic tape drive, a method for checking the length of tape wound on the hub of a reel comprising the steps of:
- inserting the reel containing the tape into the drive;
- connecting the hub of the inserted reel to a means for rotating the hub;
- holding the free end of the tape wound on the hub;
- activating the means for rotating the hub in a direction to wind the tape;
- then, activating the means for rotating the hub for a predetermined period of time with a predetermined torque in a direction to unwind the tape from the hub;
- emitting pulses by a rotational distance measuring means connected to the activated means for rotating the hub;
- counting pulses emitted by the rotational distance measuring means as a result of the rotational distance traveled by the rotated hub for the set period of time;
- storing the counted pulses;
- indicating the length of tape on the hub as a result of the stored counted pulses due to the inertia of the tape and the associated parts;
- and
- setting the torque of the means for rotating the hub for subsequent operations as a result of the indicated length of tape on the hub.
In a magnetic tape drive, a method of checking the amount of tape wound on a hub of a reel comprising the steps of:
- insuring that the hub is not rotating;
- rotating the hub for a predetermined period of time with a predetermined torque;
- determining the rotational distance traveled by the rotated hub for the set period of time;
- and
- indicating the amount of tape on the hub as a result of the determined rotational distance traveled for the set period of time due to the inertia of the tape and the associated parts.
In a magnetic tape drive, a method for checking the length of tape wound on the hub of a reel comprising the steps of:
- inserting the reel containing the tape into the drive;
- connecting the hub of the inserted reel to a means for rotating the hub;
- insuring that the hub is not rotating;
- then, activating the means for rotating the hub for a predetermined period of time with a predetermined torque;
- emitting pulses by a rotational distance measuring means connected to the activated means for rotating the hub;
- counting pulses emitted by the rotational distance measuring means as a result of the rotational distance traveled by the rotated hub for the set period of time;
- storing the counted pulses;
- indicating the length of tape on the hub as a result of the stored counted pulses due to the inertia of the tape and the associated parts;
- and
- setting the torque of the means for rotating the hub for subsequent operations as a result of the indicated length of tape on the hub.
Dependencies are inferred from the claim text.