Patent US3915365A successfully refreshed from Google Patents.
US3915365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cartridge tape player drive system
Assignee: Motorola Solutions Inc
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Filing: 1972-12-26
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Granted: 1975-10-28
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Expires: 1992-12-26
Abstract
Abstract A tape drive system for a cartridge tape player having a small thickness includes a DC motor which has a stator with a plurality of field windings, and a rotor with a permanently magnetized ring magnet coaxially surrounding the stator. Brushes on the rotor engage contacts on the stator to energize the field windings in sequence. A drive wheel connected to the rotor is coupled by a drive belt to a capstan pulley, which is larger than the drive wheel, to drive the capstan of the tape drive system, with the faster rotating rotor providing a flywheel effect to stabilize the drive. A tachometer generator includes a ring gear which is connected to the rotor and has a large number of teeth around its periphery cooperating with segments of a coaxial ring magnet. A pickup coil adjacent the ring magnet is connected to a control circuit which is coupled to the motor field windings to energize the same, with the control circuit changing the drive current to compensate for incremental changes in motor speed.
Inventors
- 👤 Melvin A Lace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:44
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/54; G11B15/1883; G11B15/1891; H; H02; H02K; H02K23/00; H02K23/62; H02K7/00; H02K7/10; H02K7/1004; H02K7/20; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; H02P7/2913
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
157 words
A tape drive system for a cartridge tape player including in combination: motor means having a stator and a rotor, and means supporting said rotor for rotation, said rotor operating at a first rotary speed and having a portion coaxially surrounding said stator which includes most of the weight of said rotor, capstan means, and means rotatably supporting said capstan means, and speed reducing means coupling said rotor to said capstan means for driving said capstan means at a rotary speed less than said first rotary speed, said rotor being of a construction and operating at a speed to provide a moment to store a predetermined amount of energy, and said capstan means being constructed and operating at a speed to provide a moment to store substantially less energy than said rotor, said speed reducing means applying the moment of said rotor to said capstan means to maintain the rotational speed of said capstan means substantially constant.
Claim 2
Dependent Claim
157 words
A tape drive system for a cartridge tape player including in combination: motor means having a stator and a rotor, and means supporting said rotor for rotation, said rotor operating at a first rotary speed and having a portion coaxially surrounding said stator which includes most of the weight of said rotor, capstan means, and means rotatably supporting said capstan means, and speed reducing means coupling said rotor to said capstan means for driving said capstan means at a rotary speed less than said first rotary speed, said rotor being of a construction and operating at a speed to provide a moment to store a predetermined amount of energy, and said capstan means being constructed and operating at a speed to provide a moment to store substantially less energy than said rotor, said speed reducing means applying the moment of said rotor to said capstan means to maintain the rotational speed of said capstan means substantially constant.
Claim 3
Dependent Claim
21 words
The tape drive system of claim 1 wherein said rotor includes an annular portion surrounding said stator which includes magnet means.
Claim 4
Dependent Claim
33 words
The tape drive system of claim 1 wherein said motor means comprises a direct current motor having a wound stator, and said rotor includes a permanently magnetized annular magnet which surrounds said stator.
Claim 5
Dependent Claim
39 words
The tape drive system of claim 1 wherein said speed reducing means includes a drive wheel connected to said rotor, a reduction pulley connected to said capstan, and a drive belt coupling said drive wheel to said reduction pulley.
Claim 6
Dependent Claim
39 words
The tape drive system according to claim 4 wherein said speed reducing means further includes an idler roller rotatably secured to said base and engaging said drive belt in a position to reduce side thrust from said drive wheel.
Claim 7
Dependent Claim
58 words
The tape drive system of claim 1 including a wheel of magnetic material having teeth thereon coupled to said rotor, magnetic means coaxial with said wheel, and coil means adjacent said magnetic means, whereby rotation of said wheel causes a current to be induced in said coil means having a frequency proportional to the speed of said rotor.
Claim 8
Dependent Claim
39 words
The tape drive system of claim 6 wherein said stator includes a magnetic structure with winding means thereon, and including control means coupled between said coil means and said winding means to control the speed of said motor means.
Claim 9
Dependent Claim
45 words
The tape drive system of claim 7 wherein said magnetic means includes a plurality of magnet segments about said wheel, and said coil means includes a pickup coil adjacent said magnet segments, said coil having an alternating current induced therein by rotation of said wheel.
Claim 10
Dependent Claim
33 words
The tape drive system of claim 8 wherein adjacent magnet segments have poles of opposite polarity and the number of magnet segments of each polarity equals the number of teeth on said wheel.
Claim 11
Dependent Claim
63 words
The tape drive system of claim 1 wherein said stator includes a magnetic structure with winding means thereon, and including means producing a signal having a frequency responsive to motor speed, and control means connected to said signal producing means and responsive to the signal therefrom for controlling the current to said winding means to thereby control the speed of said motor means.
Claim 12
Dependent Claim
106 words
The tape drive system according to claim 10 wherein said control means includes frequnecy selective amplifier means having an input and an output, said input being coupled to said signal producing means, and a current control stage having control and load electrodes, said load electrodes being coupled to said winding means of said motor means and said control electrode being coupled to said output of said amplifier means, said amplifier means being responsive to a predetermined frequency to operate said current control stage to control the current applied to said stator to cause said motor means to operate at a speed related to said predetermined frequency.
Claim 13
Dependent Claim
31 words
The tape drive system according to claim 11 wherein said amplifier means includes an operational amplifier and a negative feedback loop including a twin ''''T'''' filter connected to said operational amplifier.
Claim 14
Dependent Claim
28 words
The tape drive system according to claim 12 including detector means connected between said output of said operational amplifier and said control electrode of said current control stage.
Claim 15
Dependent Claim
56 words
The combination according to claim 14 wherein said sensing means includes a magnetic tooth wheel coupled to the rotor, magnetic means coaxial with said tooth wheel, and coil means coupled to said magnetic means, rotation of said tooth wheel inducing in said coil means a current having a frequency proportional to the speed of said rotor.
Claim 16
Dependent Claim
56 words
The tape drive system according to claim 15 wherein said magnetic means includes a ring magnet having a plurality of segments coaxially surrounding said tooth wheel, with adjacent magnet segments having magnetic poles of opposite polarities, and the number of poles of each polarity being the same as the number of teeth in said tooth wheel.
Claim 17
Dependent Claim
152 words
A motor drive system including in combination: motor means having a stator and a rotor, and means supporting said rotor for rotation, said rotor operating at a first rotary speed and having a portion coaxially surrounding said stator which includes most of the weight of said rotor, shaft means, and means rotatably supporting said shaft means, and speed reducing means coupling said rotor to said shaft means for driving said shaft means at a rotary speed less than said first rotary speed, said rotor being of a construction and operating at a speed to provide a moment to store a predetermined amount of energy, and said shaft means being constructed and operating at a speed to provide a moment to store substantially less energy than said rotor, said speed reducing means applying the moment of said rotor to said shaft means to maintain the rotational speed of said shaft means substantially constant.
Claim 18
Dependent Claim
152 words
A motor drive system including in combination: motor means having a stator and a rotor, and means supporting said rotor for rotation, said rotor operating at a first rotary speed and having a portion coaxially surrounding said stator which includes most of the weight of said rotor, shaft means, and means rotatably supporting said shaft means, and speed reducing means coupling said rotor to said shaft means for driving said shaft means at a rotary speed less than said first rotary speed, said rotor being of a construction and operating at a speed to provide a moment to store a predetermined amount of energy, and said shaft means being constructed and operating at a speed to provide a moment to store substantially less energy than said rotor, said speed reducing means applying the moment of said rotor to said shaft means to maintain the rotational speed of said shaft means substantially constant.
Claim 19
Dependent Claim
32 words
The drive system of claim 17 wherein said motor means includes a direct current motor having a wound stator, and said rotor includes a permanently magnetized annular magnet which surrounds said stator.
Claim 20
Dependent Claim
57 words
The drive system of claim 17 wherein said speed reducing means includes a drive wheel connected to said rotor, a reduction pulley connected to said drive shaft, a drive belt coupling said drive wheel to said reduction pulley, and an idler roller engaging said drive belt in a position to reduce side thrust from said drive wheel.
Claim 21
Dependent Claim
74 words
The drive system of claim 17 further including a wheel of magnetic material having teeth thereon coupled to said rotor, magnetic means coaxial with said wheel providing a flux path which includes said wheel, and coil means adjacent said magnetic means, whereby rotation of said wheel varies the flux in said flux path and causes a current to be induced in said coil means having a frequency proportional to the speed of said rotor.
Claim 22
Dependent Claim
39 words
The drive system of claim 20 wherein said stator includes a magnetic structure with winding means thereon, and further including control means coupled between said coil means and said winding means to control the speed of said motor means.
Claim 23
Dependent Claim
45 words
The drive system of claim 21 wherein said magnetic means includes a plurality of magnet segments about said wheel, and said coil means includes a pickup coil adjacent said magnet segments, with said coil having an alternating current induced therein by rotation of said wheel.
Claim 24
Dependent Claim
63 words
The drive system of claim 17 wherein said stator includes a magnetic structure with winding means thereon, and further including means prodUcing a signal having a frequency responsive to motor speed, and control means connected to said signal producing means and responsive to the signal therefrom for controlling the current to said winding means to thereby control the speed of said motor means.
Claim 25
Dependent Claim
105 words
The drive system according to claim 23 wherein said control means includes frequency selective amplifier means having an input and an output, said input being coupled to said signal producing means, and a current control stage having control and load electrodes, said load electrodes being coupled to said winding means of said motor means and said control electrode being coupled to said output of said amplifier means, said amplifier means being responsive to a predetermined frequency to operate said current control stage to control the current applied to said stator to cause said motor means to operate at a speed related to said predetermined frequency.
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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |