US3918092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Push-threading tape in a helical path
Assignee: International Business Machines Corp
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Filing: 1974-04-25
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Granted: 1975-11-04
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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 the tape along the channelized helical path. The supply spool acts as the pushing force on the tape to push the tape through the channelized path. Air jets in the spool cavity provide a large flow of air to hold the tape against the spool. Thus, when the spool unwinds, it pushes the tape out of the spool cavity rather than unwinding in the spool cavity. To prevent excessive flutter of the tape in the channelized path caused by the large flow of air in the spool cavity, the throat of the cavity connecting to the tape path is constricted. Also, large vents are provided out of the spool cavity at the throat to bleed off the large air flow.
Inventors
- 👤 William J Rueger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:13
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/66; G11B15/67; G11B15/671
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
201 words
Apparatus for threading a web from a supply spool along a circuitous path having physical and pneumatic boundaries to guide the web during threading without impeding movement of the web, said apparatus comprising: means for rotating the spool forward to supply the web to the circuitous path; means mounted adjacent the spool for picking the web leading edge off of the spool and directing the leading edge into the circuitous path; means mounted adjacent the spool for directing a large flow of air in a circular motion about the spool in the direction of forward web motion; means mounted adjacent the spool for confining the large circular flow of air to a region immediately adjacent the outer wrap of the web on the spool, the flow of air being large enough in cooperation with said confining means to restrain the uncoiling of the web about the spool whereby forward rotation of the spool pushes the web along the circuitous path rather than uncoiling the web; means positioned where the web enters the circuitous path for venting the large circular flow of air away from the web so that the large flow of air does not accompany the web along the path.
Claim 2
Dependent Claim
201 words
Apparatus for threading a web from a supply spool along a circuitous path having physical and pneumatic boundaries to guide the web during threading without impeding movement of the web, said apparatus comprising: means for rotating the spool forward to supply the web to the circuitous path; means mounted adjacent the spool for picking the web leading edge off of the spool and directing the leading edge into the circuitous path; means mounted adjacent the spool for directing a large flow of air in a circular motion about the spool in the direction of forward web motion; means mounted adjacent the spool for confining the large circular flow of air to a region immediately adjacent the outer wrap of the web on the spool, the flow of air being large enough in cooperation with said confining means to restrain the uncoiling of the web about the spool whereby forward rotation of the spool pushes the web along the circuitous path rather than uncoiling the web; means positioned where the web enters the circuitous path for venting the large circular flow of air away from the web so that the large flow of air does not accompany the web along the path.
Claim 3
Dependent Claim
41 words
The apparatus of claim 1 wherein said picking means comprises: jet means for blowing air against the forward motion of the spool to pick off the web leading edge from the spool and direct the leading edge into the circuitous path.
Claim 4
Dependent Claim
85 words
The apparatus of claim 1 wherein said confining means and directing means respectively include: cylindrical cavity surrounding the spool with the inner surface of the cavity less than .5 centimeter from the outer wrap of the web on the spool; a plurality of air jets mounted in the walls of said cavity for supplying a circular air flow between the spool the the inner surface of the cavity where the total air flow applied to the jets is in excess of a liter per second.
Claim 5
Dependent Claim
165 words
Apparatus for self-threading magnetic tape about a rotating magnetic head comprising: a channelized path for guiding the leading edge of the tape about the rotating head withouT impeding the forward motion of the tape; a tape supply spool recessed in a cavity for pushing tape out of the cavity and through said channelized path when the spool is rotated forward; a throat connecting the cavity with said channelized path for guiding the leading edge of the tape from the cavity to said channelized path; air jets in the walls of said cavity for providing a large air flow forward in the direction of rotation of the spool and toward the axis of the spool, said air jets limiting the unspooling of the tape in the cavity whereby forward rotation of the spool pushes the tape through the channelized path; air exhaust ports adjacent said throat for bleeding off the large air flow from the cavity before the air flow enters the throat and channelized path.
Claim 6
Dependent Claim
165 words
Apparatus for self-threading magnetic tape about a rotating magnetic head comprising: a channelized path for guiding the leading edge of the tape about the rotating head withouT impeding the forward motion of the tape; a tape supply spool recessed in a cavity for pushing tape out of the cavity and through said channelized path when the spool is rotated forward; a throat connecting the cavity with said channelized path for guiding the leading edge of the tape from the cavity to said channelized path; air jets in the walls of said cavity for providing a large air flow forward in the direction of rotation of the spool and toward the axis of the spool, said air jets limiting the unspooling of the tape in the cavity whereby forward rotation of the spool pushes the tape through the channelized path; air exhaust ports adjacent said throat for bleeding off the large air flow from the cavity before the air flow enters the throat and channelized path.
Claim 7
Dependent Claim
41 words
The apparatus of claim 4 wherein the cross-sectional area of said throat is much smaller than the cross-sectional area of said air exhaust ports whereby a substantial portion of the air flow in the cavity is diverted from the channelized path.
Claim 8
Dependent Claim
42 words
The apparatus of claim 5 wherein the separation between tape on said supply spool and the walls of the cavity is in the order of millimeters, while the flow of air from said air jets is at least a liter per second.
Claim 9
Dependent Claim
138 words
Method for self-threading magnetic tape along a circuitous path from a tape supply spool comprising the steps of: pushing the tape along the circuitous path with rotary motive force from the tape supply spool; constraining the tape to the circuitous path physically or pneumatically while not impeding the forward motion of the tape whereby the tape is guided along the path without buckling; directing a large flow of air at the spool and in circular motion about the spool to constrain the uncoiling of the tape about the spool so that the rotary motive force from the supply spool is converted into translational motive force on the tape; venting the large flow of air away from the tape as the tape leaves the spool and enters the circuitous path whereby tape flutter during the threading operation is controlled.
Claim 10
Dependent Claim
138 words
Method for self-threading magnetic tape along a circuitous path from a tape supply spool comprising the steps of: pushing the tape along the circuitous path with rotary motive force from the tape supply spool; constraining the tape to the circuitous path physically or pneumatically while not impeding the forward motion of the tape whereby the tape is guided along the path without buckling; directing a large flow of air at the spool and in circular motion about the spool to constrain the uncoiling of the tape about the spool so that the rotary motive force from the supply spool is converted into translational motive force on the tape; venting the large flow of air away from the tape as the tape leaves the spool and enters the circuitous path whereby tape flutter during the threading operation is controlled.
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) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |