US3781490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Web tension and speed control in a reel-to-reel web transport
Assignee: International Business Machines Corp
•
Filing: 1973-06-01
•
Granted: 1973-12-25
•
Expires: 1993-06-01
Abstract
Abstract A reel-to-reel magnetic tape transport for a relatively wide tape which carries a number of laterally spaced data track groups and prerecorded reference tracks. Control transducer means senses the reference tracks and provides an output signal indicative of increments of tape movement. This information is used to derive an output signal indicative of the tape speed, i.e., displacement per unit time. The control transducer means also provides a signal indicative of the lateral position of the tape. The control transducer means includes a tension transducer which provides an output signal indicative of the tape tension. The lateral tape position signal controls the lateral position of a data processing head. The tape speed signal and tape tension signal jointly control the two reel drive motors to maintain a desired tape speed, i.e., a desired incremental tape distance per unit time, and a desired tape tension.
Inventors
- 👤 W Phillips
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/488; G11B5/4893; G11B5/008; G11B5/00813; G11B5/00817; G11B5/54; G11B5/55; G11B5/5504; G11B5/5508
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
312 words
A reel-to-reel web transport, comprising: a supply reel and a motor for driving said supply reel, a take-up reel and a motor for driving said take-up reel, a length of unbuffered tape extending between said reels, a data processing station adjacent said length of unbuffered tape to define a tape interface, control transducer means cooperating with said length of unbuffered tape providing actual-Tape-speed and actual-tapetension signals indicative of the tape speed and tension at said interface, comparison means responsive to the two output signals and to desired-tape-speed and desired-tape-tension signals and effective to compare said signals and to originate speed and tension error signals, and control means responsive to the two error signals and connected to jointly control the energization of said supply reel motor and take-up reel motor in accordance with both error signals to maintain desired tape speed and tape tension at said interface by the implementation of a four-quadrant cartesian coordinate tape speed versus tape tension control order for said motors such that delta energization of said take-up motor minus and plus the delta energization of said supply motor is in both cases less than zero when the tape is overspeed and the tension is high; such that the delta energization of said take-up motor minus and plus the delta energization of said supply motor is in both cases greater than zero when the tape is underspeed and the tension is low; such that the delta energization of said take-up motor minus and plus the delta energization of said supply motor is less than zero and greater than zero, respectively, when the tape is underspeed and the tension is high; and such that the delta energization of said take-up motor minus and plus the delta energization of said supply motor is greater than zero and less than zero, respectively, when the tape is overspeed and the tension is low.
Claim 2
Dependent Claim
312 words
A reel-to-reel web transport, comprising: a supply reel and a motor for driving said supply reel, a take-up reel and a motor for driving said take-up reel, a length of unbuffered tape extending between said reels, a data processing station adjacent said length of unbuffered tape to define a tape interface, control transducer means cooperating with said length of unbuffered tape providing actual-Tape-speed and actual-tapetension signals indicative of the tape speed and tension at said interface, comparison means responsive to the two output signals and to desired-tape-speed and desired-tape-tension signals and effective to compare said signals and to originate speed and tension error signals, and control means responsive to the two error signals and connected to jointly control the energization of said supply reel motor and take-up reel motor in accordance with both error signals to maintain desired tape speed and tape tension at said interface by the implementation of a four-quadrant cartesian coordinate tape speed versus tape tension control order for said motors such that delta energization of said take-up motor minus and plus the delta energization of said supply motor is in both cases less than zero when the tape is overspeed and the tension is high; such that the delta energization of said take-up motor minus and plus the delta energization of said supply motor is in both cases greater than zero when the tape is underspeed and the tension is low; such that the delta energization of said take-up motor minus and plus the delta energization of said supply motor is less than zero and greater than zero, respectively, when the tape is underspeed and the tension is high; and such that the delta energization of said take-up motor minus and plus the delta energization of said supply motor is greater than zero and less than zero, respectively, when the tape is overspeed and the tension is low.
Claim 3
Dependent Claim
44 words
A reel-to-reel web transport as defined in claim 1, wherein said length of unbuffered tape includes a prerecorded reference track of known linear characteristic, and wherein said control transducer means includes a magnetic transducer responsive to said prerecorded track to provide said actual-tape-speed signal.
Claim 4
Dependent Claim
23 words
A reel-to-reel web transport as defined in claim 2, wherein said control transducer means includes a force transducer to provide said actual-tape-tension signal.
Claim 5
Dependent Claim
83 words
A web transport as defined in claim 3 wherein said tape includes a plurality of laterally positioned groups of data tracks, and said magnetic transducer provides an actual-lateral-tape-position signal; and including a data processing head adapted to selectively operate with one of said groups of data tracks, a head actuator connected to said head control the lateral position thereof, and means responsive to said tape-position signal and effective to control said head actuator to laterally position said head relative to said data tracks.
Claim 6
Dependent Claim
49 words
A web transport as defined in claim 4 wherein said data processing head includes a plurality of head groups, each one of which corresponds to one of said plurality of groups of data tracks, and means mounting said control transducer means for lateral movement with said data processing head.
Claim 7
Dependent Claim
25 words
A web transport as defined in claim 5 including means adapted to select one of said plurality of head groups as an operative head group.
Claim 8
Dependent Claim
87 words
A web transport as defined in claim 4 wherein said data processing head includes a single head group adapted to selectively correspond to one of said plurality of groups of data tracks, means mounting said control transducer means at a fixed lateral position, means movably mounting said data processing head for lateral indexing movement across said tape, and means operable to select one of said plurality of groups of data tracks as an operative track and to laterally move said data processing head into position coincident therewith.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |