Patent US3904148A successfully refreshed from Google Patents.
US3904148A
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US
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Control for self-threading tape in a helical path
Assignee: International Business Machines Corp
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Filing: 1974-04-25
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Granted: 1975-09-09
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Expires: 1994-04-25
Abstract
Abstract A wide magnetic tape is self-threaded about a helical path containing a rotating head by pushing a tape along the channelized helical path. Electronic control of the supply motor, take-up motor, channel pneumatics and tape edge guides optimizes the threading of the helical path for speed and reliability. The supply spool acts as the pushing force on the tape to push the tape through the channelized path. Motion of the tape, including speed and position, is controlled as a result of sensing the position of the end of tape as it proceeds through the thread path and attaches itself to the take-up hub. The take-up hub is a vacuum hub to assist the attachment of the tape to the hub. Motion control of the tape during thread includes selection of speeds for different portions of thread operation including stopping and reversing tape motion to assist attachment of tape to the take-up hub and straightening of tape along the helical path.
Inventors
- 👤 Samuel P Cloud
- 👤 Clement H Kalthoff
- 👤 William J Rueger
- 👤 Timothy W Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:56
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/66; G11B15/67; G11B15/671
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
174 words
Apparatus for controlling the self-threading of magnetic tape about a rotating magnetic head through a channelized thread path that wraps at least a portion of the path of the rotating head, said apparatus comprising: means for pushing the tape from a supply spool through the thread path to a vacuum-attach take-up hub; means for sensing the passage of the tape leading edge from the spool to the entrance in the thread path; means connected with the spool and responsive to said sense means for counting degrees of rotary motion by the supply spool whereby the length of tape pushed from the spool into the thread path, after the tape leading edge is sensed by said sense means, may be metered as the tape is pushed along the thread path; means connected to said counting means for controlling said pushing means to vary the speed and direction of motion of the tape through the thread path and during attachment to the takeup hub as a function of tape leading edge position in the thread path.
Claim 2
Dependent Claim
174 words
Apparatus for controlling the self-threading of magnetic tape about a rotating magnetic head through a channelized thread path that wraps at least a portion of the path of the rotating head, said apparatus comprising: means for pushing the tape from a supply spool through the thread path to a vacuum-attach take-up hub; means for sensing the passage of the tape leading edge from the spool to the entrance in the thread path; means connected with the spool and responsive to said sense means for counting degrees of rotary motion by the supply spool whereby the length of tape pushed from the spool into the thread path, after the tape leading edge is sensed by said sense means, may be metered as the tape is pushed along the thread path; means connected to said counting means for controlling said pushing means to vary the speed and direction of motion of the tape through the thread path and during attachment to the takeup hub as a function of tape leading edge position in the thread path.
Claim 3
Dependent Claim
98 words
The apparatus of claim 1 wherein said controlling means cOmprises: means for setting said pushing means to push the tape at forward exit speed when said sensing means indicates the tape leading edge has not left the spool; means for setting said pushing means to push the tape at forward thread speed when said sensing means indicates the tape leading edge has entered the thread path; means for aligning the tape with the take-up hub for vacuum attachment to the hub when said counting means indicates the tape leading edge has at least partially wrapped the take-up hub.
Claim 4
Dependent Claim
60 words
The apparatus of claim 2 and in addition: means for lifting tape edge guides out of thread path when said sensing means indicates the tape leading edge has entered the thread path; means for lowering the edge guides back into the thread path when said counting means indicates the tape leading edge has at least partially wrapped the take-up hub.
Claim 5
Dependent Claim
151 words
The apparatus of claim 2 wherein said means for aligning comprises: means for reversing said pushing means to pull the tape at backward slow speed when said counting means indicates the tape leading edge has at least partially wrapped the take-up hub; means connected to the take-up hub for indicating rotary motion by the take-up hub; means for setting the rotary speed of the take-up hub to forward-attach when said indicating means indicates that the tape partially wrapping the take-up hub has pullsed the take-up hub backwards; means for setting said pushing means to push the tape at forward thread speed after a short interval whereby during said interval the tape is moving backward slow and the take-up hub is moving at forward-attach so that the tape slips on the take-up hub and is aligned with the hub and after said interval the tape begins to wind onto the take-up hub.
Claim 6
Dependent Claim
198 words
Method for controlling the threading of a web through a circuitous path where the motive force for moving the web is the rotation of the web supply spool and where guidance of the web leading edge through the circuitous path is provided physically or pneumatically, said method comprising the steps of: driving the spool forward at exit speed to push the web into the circuitous path; sensing when the web leading edge has left the spool and entered the path; driving the spool forward at thread speed after sensing the web leading edge has entered the thread path to push the web as rapidly and reliably as possible through the circuitous path to a vacuum take-up hub; sensing when the web leading edge is adjacent the vacuum take-up hub; driving the spool and take-up hub in opposite directions to slip the web relative to the hub and align the web on the hub after the leading edge is adjacent the hub; driving the spool and take-up hub forward after the web is aligned with the hub to wind a few wraps of the straightened web onto the vacuum take-up hub whereby the web is attached to the hub.
Claim 7
Dependent Claim
198 words
Method for controlling the threading of a web through a circuitous path where the motive force for moving the web is the rotation of the web supply spool and where guidance of the web leading edge through the circuitous path is provided physically or pneumatically, said method comprising the steps of: driving the spool forward at exit speed to push the web into the circuitous path; sensing when the web leading edge has left the spool and entered the path; driving the spool forward at thread speed after sensing the web leading edge has entered the thread path to push the web as rapidly and reliably as possible through the circuitous path to a vacuum take-up hub; sensing when the web leading edge is adjacent the vacuum take-up hub; driving the spool and take-up hub in opposite directions to slip the web relative to the hub and align the web on the hub after the leading edge is adjacent the hub; driving the spool and take-up hub forward after the web is aligned with the hub to wind a few wraps of the straightened web onto the vacuum take-up hub whereby the web is attached to the hub.
Claim 8
Dependent Claim
60 words
The method of claim 5 wherein the steps of sensing the position of the web leading edge include: monitoring the entrance of the circuitous path to detect the presence of the web; counting the length of web unwound from the supply spool so that the position of the web leading edge in the thread path is defined by a count.
Claim 9
Dependent Claim
87 words
The method of claim 6 and in addition the steps of: lifting web edge guides out of the path of the web when the presence of the web is sensed at the entrance of the thread path; lowering the web edge guides to guide the web in a desired path when the web leading edge is sensed adjacent the vacuum take-up hub and before slipping the web relative to the hub so that the web is in the desired path position while being slipped on the hub.
Claim 10
Dependent Claim
57 words
The method of claim 7 and in addition the steps of: stopping the take-up hub after a few wraps of web have been wound onto the hub; activating a vacuum in a vacuum column in the path of the web whereby, as the web is unspooled, a loop of the web is loaded into the vacuum column.
Claim 11
Dependent Claim
171 words
Method for controLling the threading of a web through a circuitous path where the motive force for moving the web is the rotation of the web supply spool and where guidance of the web leading edge through the circuitous path is provided physically or pneumatically, said method comprising the steps of: sensing when the web leading edge has left the spool and entered the path; driving the spool forward at thread speed after sensing the web leading edge has entered the thread path to push the web as rapidly and reliably as possible through the circuitous path to a vacuum take-up hub; sensing when the web leading edge is adjacent the vacuum take-up hub; slipping the web relative to the hub after the web leading edge is adjacent the hub whereby the slipping movement of the web allows the web to straighten on the hub; driving the take-up hub to wind a few wraps of the straightened web onto the vacuum take-up hub whereby the web is attached to the hub.
Claim 12
Dependent Claim
171 words
Method for controLling the threading of a web through a circuitous path where the motive force for moving the web is the rotation of the web supply spool and where guidance of the web leading edge through the circuitous path is provided physically or pneumatically, said method comprising the steps of: sensing when the web leading edge has left the spool and entered the path; driving the spool forward at thread speed after sensing the web leading edge has entered the thread path to push the web as rapidly and reliably as possible through the circuitous path to a vacuum take-up hub; sensing when the web leading edge is adjacent the vacuum take-up hub; slipping the web relative to the hub after the web leading edge is adjacent the hub whereby the slipping movement of the web allows the web to straighten on the hub; driving the take-up hub to wind a few wraps of the straightened web onto the vacuum take-up hub whereby the web is attached to the hub.
Claim 13
Dependent Claim
59 words
The method of claim 9 wherein the step of slipping the web comprises the steps of: reversing the spool drive to pull the web backwards slowly after the web leading edge is adjacent the take-up hub; rotating the take-up hub forward to slip the hub relative to the backward moving web whereby the web straightens itself on the hub.
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) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |