US3778005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mechanism for handling magnetic tapes
Assignee: Loewe Opta GmbH
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Filing: 1972-01-05
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Granted: 1973-12-11
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Expires: 1992-01-05
Abstract
Abstract Mechanism for selectively pulling the tape of a tape recorder forwardly or retarding the tape as required to maintain the tape under constant tension. A means for scanning tape tension controls the air gap of a magnetic eddy current coupling interposed between a constant speed driving means and an eddy current disc drivingly connected to a tape spool.
Inventors
- 👤 F Gruniger
- 👤 G Muller
- 👤 K Steiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:14
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/43
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
193 words
Mechanism for imposing torque upon a tape-containing spool of a magnetic tape-handling apparatus, comprising a constant-speed driving means, a variable magnetic eddy current coupling drivingly connected between the driving means and the spool, tape tension responsive means for scanning the tension in the tape in the span thereof extending to the spool, and means connecting the scanning means to the coupling to vary the coupling in accordance with changes in the tension of the tape, the coupling comprising a driven rotatable multiple pole magnet mounted on a first axis and an eddy current disc mounted on a second axis spaced from the first axis and parallel thereto, disposed to be acted upon by the magnetic field of the magnet, a magnetic field-influencing member made of ferro-magnetic material, means mounting the fieldinfluencing member for movement relative to the magnet and disc so as to vary the magnetic field acting between the magnet and disc, means connecting the field-influencing member for movement relative to the magnet and disc, and means connecting the fieldinfluencing member to the tape tension scanning member so as to be moved thereby to maintain the tension of the tape substantially constant.
Claim 2
Dependent Claim
193 words
Mechanism for imposing torque upon a tape-containing spool of a magnetic tape-handling apparatus, comprising a constant-speed driving means, a variable magnetic eddy current coupling drivingly connected between the driving means and the spool, tape tension responsive means for scanning the tension in the tape in the span thereof extending to the spool, and means connecting the scanning means to the coupling to vary the coupling in accordance with changes in the tension of the tape, the coupling comprising a driven rotatable multiple pole magnet mounted on a first axis and an eddy current disc mounted on a second axis spaced from the first axis and parallel thereto, disposed to be acted upon by the magnetic field of the magnet, a magnetic field-influencing member made of ferro-magnetic material, means mounting the fieldinfluencing member for movement relative to the magnet and disc so as to vary the magnetic field acting between the magnet and disc, means connecting the field-influencing member for movement relative to the magnet and disc, and means connecting the fieldinfluencing member to the tape tension scanning member so as to be moved thereby to maintain the tension of the tape substantially constant.
Claim 3
Dependent Claim
52 words
Mechanism according to claim 1, wherein the field-influencing member in at least one operative position thereof at least partially overlaps the magnet and the eddy current disc and is mounted for movement in a plane at least generally parallel to the planes of rotation of the magnet and the eddy current disc.
Claim 4
Dependent Claim
27 words
Mechanism according to claim 1, comprising means pivotally mounting the field-influencing member for oscillation about an axis spaced from and parallel to the first and second axes.
Claim 5
Dependent Claim
28 words
Mechanism according to claim 1, wherein the tension scanning means includes a lever, and comprising a spring opposing movement of the lever by increased tension in the tape.
Claim 6
Dependent Claim
18 words
Mechanism according to claim 4, comprising means for adjusting the force which the spring exerts upon the lever.
Claim 7
Dependent Claim
30 words
Mechanism according to claim 1, wherein the rotatable magnet and the eddy current disc are adjustable relative to each other radially thereof whereby to vary the magnetic field between them.
Claim 8
Dependent Claim
98 words
Mechanism according to claim 6, wherein the magnet is mounted on a fixed axis and the spool is mounted for adjustment radially of the magnet, the tension scanning means Is a lever carrying a ramp-like cam, and comprising a cam-following roller mounting to move laterally with the spool, and means constantly urging the cam-following roller against the cam, the cam being of such configuration as to vary the magnetic field between the magnet and the eddy current disc so as to subject the spool to a torque which varies to compensate for changes in tension in the tape.
Claim 9
Dependent Claim
29 words
Mechanism according to claim 1, comprising two spools between which the magnetic tape is selectively reversed, and a magnetic coupling interposed between the driving means and the respective spools.
Claim 10
Dependent Claim
50 words
Mechanism according to claim 8, comprising a recording head past which the tape is pulled, pinch roll means for pulling the tape past such head, and a drive belt drivingly connected with the driving means and the two magnetic couplings, and at least one roll of the pinch roll set.
Claim 11
Dependent Claim
62 words
Mechanism according to claim 9, wherein the magnetic couplings each comprise rotating driven magnet and an eddy current disc cooperating therewith, a pivotally mounted member upon which the rotating magnets are disposed so that swinging of the pivotally mounted member changes the degree of overlap between the rotating magnets and the eddy current discs of the respective magnetic couplings in opposite directions.
Claim 12
Dependent Claim
27 words
Mechanism according to claim 10, comprising an actuating lever for the swinging member mounting the magnets, and a spring biasing the actuating lever toward its middle position.
Claim 13
Dependent Claim
47 words
Mechanism according to claim 10, provided with means for quickly rewinding the tape, the rotating magnet arrangements on the winding and unwinding side of the apparatus providing an increased drive moment on the winding side when thus rewinding and a decreased braking moment on the unwinding side.
Claim 14
Dependent Claim
49 words
Mechanism according to claim 8, comprising means for rewinding the tape and means for quickly unwinding the tape, the mechanism being so constructed and arranged that the torque imposed upon the winding spool by its magnetic coupling is increased whereas the torque imposed upon the unwinding spool remains unchanged.
Claim 15
Dependent Claim
189 words
Mechanism for imposing torque upon a tape-containing spool of a magnetic tape-handling apparatus, comprising a constant-speed driving means, a variable magnetic eddy current coupling drivingly connected between the driving means and the spool, tape tension responsive means for scanning the tension in the tape in the span thereof extending to the spool, and means connecting the scanning means to the coupling to vary the coupling in accordance with changes in the tension of the tape, the rotatable magnet and the eddy current disc being adjustable relative to each other radially thereof whereby to vary the magnetic field between them, the magnet being mounted on a fixed axia and the spool being mounted for adjustment radially of the magnet, the tension scanning means being a lever carrying a ramp-like cam, a cam-following roller mounted to move laterally with the spool, and means constantly urging the cam-following roller against the cam, the cam being of such configuration as to vary the magnetic field between the magnet and the eddy current disc so as to subject the spool to a torque which varies to compensate for changes in tension in the tape.
Claim 16
Dependent Claim
189 words
Mechanism for imposing torque upon a tape-containing spool of a magnetic tape-handling apparatus, comprising a constant-speed driving means, a variable magnetic eddy current coupling drivingly connected between the driving means and the spool, tape tension responsive means for scanning the tension in the tape in the span thereof extending to the spool, and means connecting the scanning means to the coupling to vary the coupling in accordance with changes in the tension of the tape, the rotatable magnet and the eddy current disc being adjustable relative to each other radially thereof whereby to vary the magnetic field between them, the magnet being mounted on a fixed axia and the spool being mounted for adjustment radially of the magnet, the tension scanning means being a lever carrying a ramp-like cam, a cam-following roller mounted to move laterally with the spool, and means constantly urging the cam-following roller against the cam, the cam being of such configuration as to vary the magnetic field between the magnet and the eddy current disc so as to subject the spool to a torque which varies to compensate for changes in tension in the tape.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |