Patent US3777075A successfully refreshed from Google Patents.
US3777075A
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US
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High speed thermal duplication of magnetic tape
Assignee: Harris Corp
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Filing: 1971-09-17
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Granted: 1973-12-04
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Expires: 1991-09-17
Abstract
Abstract A system for high speed thermal duplication of a master magnetic tape onto a slave magnetic tape utilizing a master tape transport for guiding a master tape along a predetermined path between a supply station and a take-up station, and a slave tape transport for guiding a slave tape along a second predetermined path between a supply station and a take-up station, the master tape path and slave tape path being coincident over a predetermined length. A transfer station interposed in the paths of the master tape and slave tape transports includes an arrangement for clamping together under pressure the master tape and slave tape along the predetermined distance of path coincidence. A tape heater upstream from the pressure clamp heats the slave tape to a predetermined temperature prior to pressure contact against the master tape. The system provides arrangements for mechanical isolation of tape segments in the transfer area, tension control and equalization for the master and slave tapes, preconditioning of the slave tape and a variety of heaters. A system for AC assisted thermal duplication is also described.
Inventors
- 👤 W Hendershot
- 👤 L Whitlock
- 👤 M Tallent
- 👤 D Wald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:49
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/56; G11B15/58; G11B5/00; G11B5/86; G11B5/865
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
257 words
A system for high speed thermal duplication of magnetic tape comprising: first tape transport means for transporting a master tape carrying a signal to be recorded comprising a supply reel station, a take-up reel station, means for applying predetermined tension to a master tape transported between the stations, and means for guiding the master tape between the stations in a predetermined path; second tape transport means for transporting a slave tape on which a signal is to be recorded comprising a supply reel station, a take-up reel station, means for applying predetermined tension to a slave tape transported between the stations, and means for guiding the slave tape between the stations in a predetermined path, said first and second tape transport means positioned in adjacent relationship with a portion of the respective master and slave tape paths coinciding; clamping means interposed in the paths of said first and second tape transport means for pressure clamping a master tape and slave tape in intimate contact against each other along the predetermined coinciding length of said paths; heater means along the path of the second tape transport means upstream from the clamping means for heating a slave tape transported by the second tape transport means; means for sensing the corresponding signals on the master and slave tape downstream from the heater means and clamping means and for generating a feed-back control signal proportional to the frequency difference between said signals; and means for controlling the tension on one of said tapes in accordance with said difference feed-back control signal.
Claim 2
Independent Claim
257 words
A system for high speed thermal duplication of magnetic tape comprising: first tape transport means for transporting a master tape carrying a signal to be recorded comprising a supply reel station, a take-up reel station, means for applying predetermined tension to a master tape transported between the stations, and means for guiding the master tape between the stations in a predetermined path; second tape transport means for transporting a slave tape on which a signal is to be recorded comprising a supply reel station, a take-up reel station, means for applying predetermined tension to a slave tape transported between the stations, and means for guiding the slave tape between the stations in a predetermined path, said first and second tape transport means positioned in adjacent relationship with a portion of the respective master and slave tape paths coinciding; clamping means interposed in the paths of said first and second tape transport means for pressure clamping a master tape and slave tape in intimate contact against each other along the predetermined coinciding length of said paths; heater means along the path of the second tape transport means upstream from the clamping means for heating a slave tape transported by the second tape transport means; means for sensing the corresponding signals on the master and slave tape downstream from the heater means and clamping means and for generating a feed-back control signal proportional to the frequency difference between said signals; and means for controlling the tension on one of said tapes in accordance with said difference feed-back control signal.
Claim 3
Dependent Claim
56 words
A system for thermal duplication of magnetic tape as set forth in claim 1 wherein the elements of said first and second tape transport means are mounted on a flat plate which forms an index edge For the lower edges of a master tape and slave tape mounted on the first and second tape transport means.
Claim 4
Dependent Claim
23 words
A system for thermal duplication of magnetic tape as set forth in claim 2 wherein said flat plate comprises an anodized metal plate.
Claim 5
Dependent Claim
58 words
A system for high speed thermal duplication of magnetic tape as set forth in claim 1 wherein is provided a plurality of vacuum columns interposed in the tape transport paths of the first and second tape transport means to provide precise tension control along the predetermined tape paths and to mechanically isolate portions of the tape transport paths.
Claim 6
Dependent Claim
47 words
A system for thermal duplication of magnetic tape as set forth in claim 4 wherein four vacuum columns are provided, one downstream from each of the supply reel stations and one upstream from each of the take-up reel stations of the first and second tape transport means.
Claim 7
Dependent Claim
72 words
A system for thermal duplication of magnetic tape as set forth in claim 5 wherein is provided a fifth vacuum column interposed in the tape transport path of the second tape transport means intermediate the supply reel station vacuum column and the take-up reel station vacuum column and wherein said feed-back control signal is coupled for controlling the vacuum applied to said fifth vacuum column tape by controlling tension on said tape.
Claim 8
Dependent Claim
74 words
A system for thermal duplication of magnetic tape as set forth in claim 4 wherein is provided feed-back control means for controlling the vacuum applied to one of the vacuum columns in the tape transport path of the second tape transport means in accordance with the feed-back control signal to compensate for dynamic tensional errors and eliminate differences between the signals on a slave tape and master tape transported by the tape transport means.
Claim 9
Dependent Claim
56 words
A system for thermal duplication of magnetic tape as set forth in claim 1 wherein is provided in the path of the second tape transport means upstream from the heater means and clamping means, a tape preconditioner comprising a heater followed by a cooler for preconditioning a slave tape carried by the second tape transport means.
Claim 10
Dependent Claim
43 words
A system for thermal duplication of magnetic tape as set forth in claim 1 wherein said clamping means comprising means for clamping a master tape and slave tape together over a predetermined length of the tape transport paths by means of air pressure.
Claim 11
Dependent Claim
62 words
A system of thermal duplication of magnetic tape as set forth in claim 9 wherein said air pressure clamping means comprises a pair of opposed spaced apart sintered plates between which pass the master tape and slave tape carried by the first and second tape transport means, and means for applying high pressure air from the outside of each of said plates.
Claim 12
Dependent Claim
83 words
A system for thermal duplication of magnetic tape as set forth in claim 1 wherein said heater means comprises an elongate surface of heat conducting material interposed along the path of a slave tape carried by the second tape transport means, means for heating the heat conducting surface, and a vacuum slot formed in the upstream end of said surface for applying low pressure to provide intimate contact between a slave tape carried by the second tape transport means and the heating surface.
Claim 13
Dependent Claim
51 words
A system for thermal duplication of magnetic tape as set forth in claim 1 wherein said heater means is provided with thermal sensing means for measuring the temperature of the heater means and for generating a feedback control signal, and feedback control means for controlling the temperature of said heater means.
Claim 14
Dependent Claim
87 words
A system for thermal duplication of magnetic tape as set forth in claim 1 wherein said heating means upstream from the clamping means is positioned on one side of the tape transport path of the second tape transport means for heating one side of a slave tape carried by the second tape transport means and wherein is also provided a cooling means opposed to said heating means on the opposite side of a slave tape for cooling one side of a slave while hEating the other side.
Claim 15
Dependent Claim
146 words
A system for high speed thermal duplication of magnetic tape as set forth in claim 1 wherein is provided means for equalizing the tension on a master tape and slave tape carried by the first and second tape transport means comprising means for sensing the tension on a master tape carried by the first tape transport mechanism downstream from the clamping means and for generating a first feedback control signal, means for measuring the tension on a slave tape carried by the second tape transport means downstream from the clamping means for generating a second feedback control signal, means for generating a difference signal from said first and second feedback control signals, and means for controlling the tension on one of the tapes in accordance with said difference signal thereby to eliminate dynamic tensional errors and equalize the tension on the master tape and slave tape.
Claim 16
Independent Claim
227 words
A system for high speed thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: a master tape handler comprising a supply reel station, a take-up reel station, and means for guiding a master tape between the stations in a predetermined path; slave tape handling means comprising a supply reel station, a take-up reel station, means for applying predetermined tension to a slave tape transported between the stations, and means for guiding the slave tape between the stations in a predetermined path, said slave tape path and said master tape path being coincident over a predetermined length; means for moving the tapes between the stations; a transfer station interposed in the paths of the slave tape handler and master tape handler comprising means for clamping together under tension a master tape and slave tape transported by said master tape handling means and slave tape handling along the predetermined distance of path coincidence and a tape heater upstream from the clamping means in the slave tape path for heating the slave tape to a predetermined temperature prior to pressure clamping against the master tape; means for generating a signal indicating a relative elongation or contraction of one of the tapes; and means responsive to the signal for compensating for the relative elongation or contraction of said one tape to thereby equalize the relative tape lengths.
Claim 17
Independent Claim
227 words
A system for high speed thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: a master tape handler comprising a supply reel station, a take-up reel station, and means for guiding a master tape between the stations in a predetermined path; slave tape handling means comprising a supply reel station, a take-up reel station, means for applying predetermined tension to a slave tape transported between the stations, and means for guiding the slave tape between the stations in a predetermined path, said slave tape path and said master tape path being coincident over a predetermined length; means for moving the tapes between the stations; a transfer station interposed in the paths of the slave tape handler and master tape handler comprising means for clamping together under tension a master tape and slave tape transported by said master tape handling means and slave tape handling along the predetermined distance of path coincidence and a tape heater upstream from the clamping means in the slave tape path for heating the slave tape to a predetermined temperature prior to pressure clamping against the master tape; means for generating a signal indicating a relative elongation or contraction of one of the tapes; and means responsive to the signal for compensating for the relative elongation or contraction of said one tape to thereby equalize the relative tape lengths.
Claim 18
Dependent Claim
73 words
A system for thermal duplication of magnetic tape as set forth in claim 15 wherein said means for tensionally isolating the segments of master tape and slave tape in the area of the transfer station comprise a plurality of mechanical tensional arms interposed in the master tape and slave tape paths at least one tension arm downstream from each supply reel station at least one tension arm upstream from each take-up reel station.
Claim 19
Independent Claim
149 words
A system for high speed thermal duplication of a master magnetic tape onto a slave magnetic tape comprising a master tape handler for guiding the master tape between a supply station and a take-up station; a slave tape handler for guiding the slave tape between a supply station and a take-up station; means for guiding the tapes over a predetermined length through a coincident path; a transfer station at said path including means for heating the slave tape and means downstream of the heating means for pressuring the tapes into intimate contact; means for moving the tapes between their respective supply and take-up stations; means for sensing relative changes in the tape lengths downstream of the pressuring means due to elongations or contractions of one of the tapes, and means for equalizing such relative changes in the tape lengths to prevent relative distortion in recordings on the slave tape.
Claim 20
Independent Claim
149 words
A system for high speed thermal duplication of a master magnetic tape onto a slave magnetic tape comprising a master tape handler for guiding the master tape between a supply station and a take-up station; a slave tape handler for guiding the slave tape between a supply station and a take-up station; means for guiding the tapes over a predetermined length through a coincident path; a transfer station at said path including means for heating the slave tape and means downstream of the heating means for pressuring the tapes into intimate contact; means for moving the tapes between their respective supply and take-up stations; means for sensing relative changes in the tape lengths downstream of the pressuring means due to elongations or contractions of one of the tapes, and means for equalizing such relative changes in the tape lengths to prevent relative distortion in recordings on the slave tape.
Claim 21
Dependent Claim
21 words
A system according to claim 17 including means downstream of the pressuring means for cooling at least one of the tapes.
Claim 22
Dependent Claim
128 words
A system according to claim 17 including means for tensionally isolating a portion of the master tape and a portion of the slave tape in the area of the transfer station during movement of the master tape and the slave tape between their respective supply and take-up stations comprising a plurality of vacuum columns through which the tapes are guided, at least one vacuum column disposed downstream from each supply station and at least one vacuum column disposed upstream from each take-up station, each vacuum column being defined by sides and cover having a surface substantially contacting an edge of the tape in the column, and further including means for adjusting the relative position of the surface to thereby accommodate in the vacuum columns tapes of differing widths.
Claim 23
Dependent Claim
43 words
A system according to claim 19 wherein the surface is defined by a protrusion of the cover depending into a chamber of the vacuum column, and including a plurality of covers having protrusions of differing lengths to accommodate the taps of differing widths.
Claim 24
Dependent Claim
116 words
A system for thermal duplication of magnetic tapes as set forth in claim 17 wherein the sensing means comprises means for sensing a master tape signal on the master tape downstream from the transfer station and for generating a first signal, means for sensing a slave tape signal on the slave tape downstream from the transfer station and for generating a second signal, and means for generating the difference signal from said first and second signals to provide a feedback control signal, and wherein the equalizing means comprises means for controlling in accordance with said feedback difference signal the tension on the slave tape to eliminate dynamic tensional errors between the slave tape and master tape.
Claim 25
Dependent Claim
103 words
A system for thermal duplication of magnetic tape as set forth in claim 21 including means for tensionally isolating segments of the master tape and slave tape in the transfer station area during transport of the master tape and slave tape comprising first vacuum columns downstream from each supply station and second vacuum columns upstream from each take-up station and wherein is also provided a third vacuum column in the slave tape path of the slave tape handling means intermediate the first and second vacuum columns, said third vacuum column having a variable vacuum controlled by said difference signal and feed-back control means.
Claim 26
Dependent Claim
131 words
Apparatus for the thermal duplication of magnetic tape comprising: means for guiding a master magnetic tape from a master supply station to a master take-up station along a master tape path; means for guiding a slave magnetic tape from a slave supply station to a slave take-up station along a slave tape path, means disposed between the respective stations for pressuring the tapes into intimate contact over a predetermined length of the paths, a heater for heating the slave tape path to a predetermined temperature to effect magnetic recordation thereon while the slave tape is in initmate contact with the master tape; and means downstream of the pressuring means positioned to intercept at least one of the tape moving between its supply station and its take-up station for cooling the tape.
Claim 27
Dependent Claim
131 words
Apparatus for the thermal duplication of magnetic tape comprising: means for guiding a master magnetic tape from a master supply station to a master take-up station along a master tape path; means for guiding a slave magnetic tape from a slave supply station to a slave take-up station along a slave tape path, means disposed between the respective stations for pressuring the tapes into intimate contact over a predetermined length of the paths, a heater for heating the slave tape path to a predetermined temperature to effect magnetic recordation thereon while the slave tape is in initmate contact with the master tape; and means downstream of the pressuring means positioned to intercept at least one of the tape moving between its supply station and its take-up station for cooling the tape.
Claim 28
Dependent Claim
15 words
Apparatus according to claim 23 wherein the cooling means includes means for cooling both tapes.
Claim 29
Dependent Claim
84 words
A system for thermal duplication of magnetic tape as set forth in claim 17 wherein the slave tape heating means comprises an elongate surface of heat conducting material positioned to contact the slave tape between the slave tape supply and take-up stations, a plurality of electrical heaters embedded in said surface, means for sensing the temperature of said surface and for generating a feedback control signal, and means for controlling the power supply to said electrical heaters in accordance with the feedback control signal.
Claim 30
Dependent Claim
57 words
A system for thermal duplication of magnetic tape as set forth in claim 25 wherein the surface of the material is provided with a vacuum slot at its upstream end and wherein there is provided means for applying low pressure to the vacuum slot to provide intimate contact between a slave tape and the heat conducting surface.
Claim 31
Dependent Claim
41 words
A systEm for thermal duplication of magnetic tape as set forth in claim 17 wherein there is provided upstream from the transfer station a slave tape pre-conditioner positioned to intercept the slave tape and comprising a heater followed by a cooler.
Claim 32
Dependent Claim
44 words
A system for thermal duplication of magnetic tape as set forth in claim 17 wherein said tape heating means comprises means for heating one surface of the slave tape and wherein it is also provided means for cooling the opposite surface of said tape.
Claim 33
Dependent Claim
36 words
A system for thermal duplication of magnetic tape as set forth in claim 17 wherein it is provided means for cooling the master tape and means for cooling the slave tape downstream from said transfer station.
Claim 34
Independent Claim
146 words
A system for thermal duplication of a master magnetic tape signal onto a slave magnetic tape comprising: means for transporting the master tape along a predetermined path from a supply station to take-up station; means for transporting the slave tape along a predetermined path from a supply station to a take-up station; means for pressure clamping the master tape and slave tape against each other along a predetermined length of the respective paths; means for heating the slave tape to a predetermined temperature upstream from the pressure clamping means; means for sensing the comparing the master tape signal and duplicate slave tape signal to detect distortion in the duplicate slave tape signal and for generating a feedback control signal is accordance with detected distortion; and means for controlling the tension on one of said master tape or slave tape in response to said feedback control signal.
Claim 35
Independent Claim
146 words
A system for thermal duplication of a master magnetic tape signal onto a slave magnetic tape comprising: means for transporting the master tape along a predetermined path from a supply station to take-up station; means for transporting the slave tape along a predetermined path from a supply station to a take-up station; means for pressure clamping the master tape and slave tape against each other along a predetermined length of the respective paths; means for heating the slave tape to a predetermined temperature upstream from the pressure clamping means; means for sensing the comparing the master tape signal and duplicate slave tape signal to detect distortion in the duplicate slave tape signal and for generating a feedback control signal is accordance with detected distortion; and means for controlling the tension on one of said master tape or slave tape in response to said feedback control signal.
Claim 36
Dependent Claim
38 words
A system for thermal duplication of magnetic tape as set forth in claim 30 wherein the means for controlling tension comprises means for controlling tension on the slave tape upstream from the heating means and pressure clamping means.
Claim 37
Dependent Claim
35 words
A system for thermal duplication of magnetic tape as set forth in claim 30 wherein the means for controlling tension comprises means for controlling tension on the slave tape downstream from the pressure clamping means.
Claim 38
Dependent Claim
35 words
A system for thermal duplication of magnetic tape as set forth in claim 30 wherein the means for controlling tension comprises means for controlling tension on the master tape upstream from the pressure clamping means.
Claim 39
Independent Claim
263 words
A system for AC assisted thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: master tape handling means for transporting the master tape comprising a supply station, a take-up station, means for applying predetermined tension to a master tape transported between the stations, and means for guiding a master tape between the stations in a predetermined path; slave tape handling means for transporting a slave tape comprising a supply station, a take-up station, means for applying predetermined tension to a slave tape transported between the stations, and means for guiding a slave tape between the stations in a predetermined path, said slave tape path and master tape paths being coincident over a predetermined length; and a transfer station interposed in the paths of the master tape and slave tape handling means comprising means for pressure clamping a master tape and slave tape transported by said master tape and slave tape handling means over the predetermined coincident length of the master tape and slave tape paths, a magnetic head along the upstream end of the coincident length of said paths and means for applying an AC signal to the magnetic head in order to apply an AC field to the clamped slave tape and master tape at the upstream end of the pressure clamping means, and heater means positioned in the path of a slave tape upstream from said clamping means and magnetic head for heating a slave tape transported through said transfer station thereby to increase the ratio of the coercivity of the master tape to the slave tape.
Claim 40
Independent Claim
263 words
A system for AC assisted thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: master tape handling means for transporting the master tape comprising a supply station, a take-up station, means for applying predetermined tension to a master tape transported between the stations, and means for guiding a master tape between the stations in a predetermined path; slave tape handling means for transporting a slave tape comprising a supply station, a take-up station, means for applying predetermined tension to a slave tape transported between the stations, and means for guiding a slave tape between the stations in a predetermined path, said slave tape path and master tape paths being coincident over a predetermined length; and a transfer station interposed in the paths of the master tape and slave tape handling means comprising means for pressure clamping a master tape and slave tape transported by said master tape and slave tape handling means over the predetermined coincident length of the master tape and slave tape paths, a magnetic head along the upstream end of the coincident length of said paths and means for applying an AC signal to the magnetic head in order to apply an AC field to the clamped slave tape and master tape at the upstream end of the pressure clamping means, and heater means positioned in the path of a slave tape upstream from said clamping means and magnetic head for heating a slave tape transported through said transfer station thereby to increase the ratio of the coercivity of the master tape to the slave tape.
Claim 41
Dependent Claim
51 words
A system for AC assisted thermal duplication of magNetic tape as set forth in claim 34 wherein said heater means is adapted to heat the slave tape to a predetermined temperature to afford a coercivity ratio of the master tape to the slave tape of approximately 2 to 1 or greater.
Claim 42
Independent Claim
142 words
A system for AC assisted thermal duplication of a master magnetic tape onto a slave magnetic tape of the type using means for transporting the master tape and slave tape over predetermined paths between supply stations and take-up stations, the master tape and slave tape paths being coincident over a predetermined length, means for pressure clamping the master tape and slave tape against each other along the predetermined coincident length, and means for heating the slave tape upstream from the pressure clamping means, the improvement comprising: a magnetic head along the upstream end of the coincident path length of the master tape and slave tape and means for supplying an AC signal to the magnetic head in order to apply an AC magnetic field to the pressure clamped slave tape and master tape at the upstream end of the pressure clamping means.
Claim 43
Independent Claim
142 words
A system for AC assisted thermal duplication of a master magnetic tape onto a slave magnetic tape of the type using means for transporting the master tape and slave tape over predetermined paths between supply stations and take-up stations, the master tape and slave tape paths being coincident over a predetermined length, means for pressure clamping the master tape and slave tape against each other along the predetermined coincident length, and means for heating the slave tape upstream from the pressure clamping means, the improvement comprising: a magnetic head along the upstream end of the coincident path length of the master tape and slave tape and means for supplying an AC signal to the magnetic head in order to apply an AC magnetic field to the pressure clamped slave tape and master tape at the upstream end of the pressure clamping means.
Claim 44
Independent Claim
102 words
A system for AC assisted thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: means for transporting the master tape along a predetermined path from a supply station to a take-up station; means for pressure clamping the master tape and slave tape against each other along a predetermined length of the respective paths; means for heating the slave tape upstream of the pressure clamping means to a temperature less than the Curie temperature of the magnetic material comprising the slave tape; and means for supplying an AC magnetic field to the pressure clamped slave tape and master tape.
Claim 45
Independent Claim
102 words
A system for AC assisted thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: means for transporting the master tape along a predetermined path from a supply station to a take-up station; means for pressure clamping the master tape and slave tape against each other along a predetermined length of the respective paths; means for heating the slave tape upstream of the pressure clamping means to a temperature less than the Curie temperature of the magnetic material comprising the slave tape; and means for supplying an AC magnetic field to the pressure clamped slave tape and master tape.
Claim 46
Dependent Claim
177 words
A methof for thermal duplication of magnetic tape comprising: transporting a master tape carrying a signal to be reproduced along a predetermined path from a supply station to a take-up station; transporting a slave tape on which the signal is to be duplicated along a second predetermined path from a supply station to a take-up station; heating the slave tape to a temperature in the vicinity of the Curie temperature of the magnetic material comprising the tape; pressure clamping the slave tape and master tape against each other after heating the slave tape and maintaining said pressure contact over a predetermined path length so that the master and slave tapes are in pressure contact while the slave tape cools to a temperature below said Curie point; sensing the signals on the master tape and slave tape after pressure clamping; comparing said signals; generating a feedback control signal in accordance with detected distortion in the slave tape signal; and controlling the tension on one of said member tape or slave tape in response to said feedback control signal.
Claim 47
Dependent Claim
177 words
A methof for thermal duplication of magnetic tape comprising: transporting a master tape carrying a signal to be reproduced along a predetermined path from a supply station to a take-up station; transporting a slave tape on which the signal is to be duplicated along a second predetermined path from a supply station to a take-up station; heating the slave tape to a temperature in the vicinity of the Curie temperature of the magnetic material comprising the tape; pressure clamping the slave tape and master tape against each other after heating the slave tape and maintaining said pressure contact over a predetermined path length so that the master and slave tapes are in pressure contact while the slave tape cools to a temperature below said Curie point; sensing the signals on the master tape and slave tape after pressure clamping; comparing said signals; generating a feedback control signal in accordance with detected distortion in the slave tape signal; and controlling the tension on one of said member tape or slave tape in response to said feedback control signal.
Claim 48
Dependent Claim
33 words
A method for thermal duplication of magnetic tape as set forth in claim 38 wherein the step of controlling tension comprises controlling tension on the slave tape prior to heat and pressure clamping.
Claim 49
Dependent Claim
32 words
A method for thermal duplication of magnetic tape as set forth in claim 38 wherein the step of controlling tension comprising controlling tension on the slave tape after heating the pressure clamping.
Claim 50
Dependent Claim
30 words
A method for thermal duplication of magnetic tape as set foth in claim 38 wherein the step of controlling tension comprises controlling tension on the master tape before pressure clamping.
Claim 51
Dependent Claim
55 words
A method for thermal duplication of magnetic tape as set forth in claim 38 wherein said step of pressure clamping the master and slave tapes against each other comprises applying air pressure against the master and slave tapes over a predetermined distance whereby the master and slave are maintained in pressure contact over said distance.
Claim 52
Dependent Claim
37 words
A method for thermal magnetic duplication of magnetic tape as set forth in claim 38 wherein it is also provided the step of applying an AC magnetic field to the pressure clAmping slave tape and master tape.
Claim 53
Dependent Claim
58 words
A method for thermal duplication of magnetic tape as set forth in claim 38 wherein the step of heating comprises the step of heating the side of the slave tape facing the master tape and wherein is provided the additional step of cooling at the same time the side of the slave tape away from the master tape.
Claim 54
Dependent Claim
34 words
A method of thermal duplication of magnetic tape as set forth in claim 38 wherein the step of heating comprises heating the slave tape by contacting said tape against a thermally conducting heated surface.
Claim 55
Dependent Claim
36 words
A method of thermal duplication of magnetic tape as set forth in claim 38 wherein the heating step comprises flash heating the magnetizable layer of the magnetic tape thereby restricting heat dissipation in the tape substrate.
Claim 56
Independent Claim
160 words
A method for thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: transporting a master tape carrying a signal to be reproduced along a predetermined path; transporting a slave tape on which the signal is to be duplicated along a second predetermined path; heating the slave tape to a temperature in the vicinity of the Curie temperature of the magnetic material comprising the tape; applying air pressure to side lengths of the slave tape and master tape in a direction to force the master tape and slave tape against each other after heating the slave tape, and maintaining said pressure contact over a predetermined distance so that the master tape and slave tape are in pressure contact while the slave tape cools to a temperature below said Curie point; and tensionally isolating the master tape and slave tape during heating and during application of air pressure to side lengths of the master tape and slave tape.
Claim 57
Independent Claim
160 words
A method for thermal duplication of a master magnetic tape onto a slave magnetic tape comprising: transporting a master tape carrying a signal to be reproduced along a predetermined path; transporting a slave tape on which the signal is to be duplicated along a second predetermined path; heating the slave tape to a temperature in the vicinity of the Curie temperature of the magnetic material comprising the tape; applying air pressure to side lengths of the slave tape and master tape in a direction to force the master tape and slave tape against each other after heating the slave tape, and maintaining said pressure contact over a predetermined distance so that the master tape and slave tape are in pressure contact while the slave tape cools to a temperature below said Curie point; and tensionally isolating the master tape and slave tape during heating and during application of air pressure to side lengths of the master tape and slave tape.
Claim 58
Independent Claim
99 words
A method for thermal duplication of magnetic tape comprising: transporting a master magnetic tape carrying a signal to be reproduced along a predetermined path; transporting a slave magnetic tape on which the signal is to be duplicated along a second predetermined path; heating the slave tape to below the Curie temperature for the magnetic material comprising the slave tape; pressure contacting the slave tape and master tape against each other after heating the slave tape and maintaining said pressure contact over a predetermined path length; and applying an AC magnetic field to the pressure contacted slave and master tapes.
Claim 59
Independent Claim
99 words
A method for thermal duplication of magnetic tape comprising: transporting a master magnetic tape carrying a signal to be reproduced along a predetermined path; transporting a slave magnetic tape on which the signal is to be duplicated along a second predetermined path; heating the slave tape to below the Curie temperature for the magnetic material comprising the slave tape; pressure contacting the slave tape and master tape against each other after heating the slave tape and maintaining said pressure contact over a predetermined path length; and applying an AC magnetic field to the pressure contacted slave and master tapes.
Claim 60
Independent Claim
125 words
A method for thermal duplication of magnetic tape comprising: transporting a master magnetic tape carrying a signal to be reproduced, along a predetermined path from a supply station to a take-up station; transporting a slave magnetic tape on which the signal is to be duplicated along a second predetermined path from a supply station to a take-up station; heating the slave tape to sufficient temperature so that the coercivity ratio of the master tape to the slave tape is approximately 2 : 1 or greater; pressure contacting the slave tape and master tape against each other after heating the slave tape and maintaining said pressure contact over a predetermined path length; and applying an AC magnetic field to the pressure contacted slave and master tapes.
Claim 61
Independent Claim
125 words
A method for thermal duplication of magnetic tape comprising: transporting a master magnetic tape carrying a signal to be reproduced, along a predetermined path from a supply station to a take-up station; transporting a slave magnetic tape on which the signal is to be duplicated along a second predetermined path from a supply station to a take-up station; heating the slave tape to sufficient temperature so that the coercivity ratio of the master tape to the slave tape is approximately 2 : 1 or greater; pressure contacting the slave tape and master tape against each other after heating the slave tape and maintaining said pressure contact over a predetermined path length; and applying an AC magnetic field to the pressure contacted slave and master tapes.
References Cited (Backward Citations)
US3037090A
Cited
US3465105A
Cited
US3161120A
Cited
US3364496A
Cited
US3441342A
Cited
US3485961A
Cited
US3472971A
Cited
US3633807A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |