US3834648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for sensing diameter of tape pack on storage reel
Assignee: Ampex Corp
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Filing: 1972-03-15
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Granted: 1974-09-10
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Expires: 1992-03-15
Abstract
Abstract An end of tape sensor for sensing the approaching end of a supply of magnetic tape on a storage reel on a tape transport and for producing a control signal for controlling the tape drive means includes a feed tachometer means for detecting longitudinal tape speed, reel tachometer means for detecting reel rotational speed, digital counter means responsive to said feed and reel tachometer means for developing a digital signal representing the ratio of longitudinal tape speed to reel rotational speed, a tape pack diameter selector for producing a preselected digital ratio of longitudinal tape speed to reel rotational speed corresponding to a desired terminal tape pack diameter and digital comparator means for comparing said digital signal with said preselected digital ratio, said comparator including a storage register which produces a control signal to control said tape drive means when said digital signal and said preselected digital ratio achieve a plurality of matches in succession.
Inventors
- 👤 M Rose
- 👤 H Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:24
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/54; G11B27/00; G11B27/10; G11B27/11; G11B27/13
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
289 words
An apparatus for sensing the approaching end of a supply of magnetic tape on a first storage reel when the tape is being transferred on a tape transport to a second storage reel and including, tape drive means responsive to a tape drive control signal, feed and reel tachometer means for generating trains of pulses representative respectively of the longitudinal speed of the magnetic tape and the instantaneous rotation speed of the storage reels, and digital counter means, the apparatus comprising: direction sensing and switching means operatively coupled to the tape for detecting the instantaneous direction of travel thereof and responsive to the tape to operatively couple the digital counter means to the reel tachometer means of the reel which is approaching the end-of-tape condition; a synchronizing circuit coupled to the direction sensing and switching means and to the feed tachometer means for adjusting the phase of the reel tachometer pulses relative to the feed tachometer pulses; said digital counter means being responsive to said feed and reel tachometer means for developing a digital signal representing a ratio of said longitudinal tape speed to said reel rotational speed; tape pack diameter selector for producing a preselected stop digital word representing a desired ratio of longitudinal tape speed to reel rotational speed corresponding to a preselectable terminal tape pack diameter; digital comparator means coupled to the diameter selector and to the digital counter means for comparing said digital signal with said preselected stop digital word; and circuit means including a storage register responsive to the comparator means and to the synchronizing circuit to produce a control signal to stop said tape drive means when said digital signal matches said preselected stop digital word for a plurality of matches in succession.
Claim 2
Independent Claim
289 words
An apparatus for sensing the approaching end of a supply of magnetic tape on a first storage reel when the tape is being transferred on a tape transport to a second storage reel and including, tape drive means responsive to a tape drive control signal, feed and reel tachometer means for generating trains of pulses representative respectively of the longitudinal speed of the magnetic tape and the instantaneous rotation speed of the storage reels, and digital counter means, the apparatus comprising: direction sensing and switching means operatively coupled to the tape for detecting the instantaneous direction of travel thereof and responsive to the tape to operatively couple the digital counter means to the reel tachometer means of the reel which is approaching the end-of-tape condition; a synchronizing circuit coupled to the direction sensing and switching means and to the feed tachometer means for adjusting the phase of the reel tachometer pulses relative to the feed tachometer pulses; said digital counter means being responsive to said feed and reel tachometer means for developing a digital signal representing a ratio of said longitudinal tape speed to said reel rotational speed; tape pack diameter selector for producing a preselected stop digital word representing a desired ratio of longitudinal tape speed to reel rotational speed corresponding to a preselectable terminal tape pack diameter; digital comparator means coupled to the diameter selector and to the digital counter means for comparing said digital signal with said preselected stop digital word; and circuit means including a storage register responsive to the comparator means and to the synchronizing circuit to produce a control signal to stop said tape drive means when said digital signal matches said preselected stop digital word for a plurality of matches in succession.
Claim 3
Dependent Claim
81 words
The apparatus of claim 1 wherein said tape pack diameter selector produces an additional preselected slow digital word prior to producing said preselected stop digital word, said slow digital word corresponding to a tape pack diameter at which said magnetic tape is slowed down prior to shutoff; and said circuit means produces a preliminary control signal to slow down said tape drive means when said digital signal and said additional preselected slow digital word achieve a plurality of matches in succession.
Claim 4
Dependent Claim
16 words
The apparatus of claim 2 wherein each of said pluraliTy of matches is greater than three.
Claim 5
Dependent Claim
162 words
The apparatus of claim 2 wherein said tape drive means includes a normal drive mode, a slow drive mode and a stop mode, and the combination is further defined by said tape pack diameter selector having a first mode in which the preselected slow digital word is generated and a second mode in which the preselected stop digital word is generated, said storage register of the circuit means being responsive to the output signals of said comparator means and said synchronizing circuit to indicate the plurality of successive matches between the signal developed on said digital counter means and the preselected slow digital word to dispose said tape drive means in said slow drive mode, and further responsive thereafter to the output signals of said comparator means and synchronizing circuit to indicate the plurality of successive matches between the signal developed by said digital counter means and the preselected stop digital word to dispose said tape drive means in said stop mode.
Claim 6
Dependent Claim
67 words
The apparatus of claim 4 wherein the circuit means further includes, a slow latch circuit which changes state in response to the consecutive matches generated via the storage register to switch the tape drive means to the slow drive mode, said slow latch circuit simultaneously switching the tape pack diameter selector into the second mode to allow the latter to then develop the preselected stop digital word.
Claim 7
Dependent Claim
69 words
The apparatus of claim 5 wherein the slow latch circuit includes an AND gate, and the storage register is read in synchronization with the pulse train from a reel tachometer means in response to the synchronizing circuit to produce the consecutive matches during both the slow drive and the stop modes, wherein the AND gate is enabled during the stop mode to terminate operation of the tape drive means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |