US3648263A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data head actuation apparatus and circuit
Assignee: Individual
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Filing: 1970-05-11
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Granted: 1972-03-07
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Expires: 1990-05-11
Abstract
Abstract Magnetic discs and drums are employed as computer memories and have data heads aerodynamically supported on the boundary air layer as the memory medium rotates. The data heads are mounted on leaf springs and are lifted from the magnetic surface when the magnetic medium is stopped. The data heads are driven toward the surface into an aerodynamic lift relationship adjacent the moving magnetic surface as the surface approaches top speed. The data head driver is a solenoid which receives increased energization in the last stages of magnetic medium drive motor speed increase.
Inventors
- 👤 George H Kunstadt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:48
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/18; G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/56; G11B5/58; G11B5/60; G11B5/6005
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
187 words
Data head actuation apparatus comprising: a frame; a magnetic memory device rotatably mounted on said frame and having a magnetizable surface; a rotary motor mounted on said frame and connected to said memory device for rotating said memory device at a running speed to create an air boundary layer at said surface, said rotary motor including an unimpeded main motor winding and a starting winding, the voltage drop across said starting winding being a function of motor speed, phase shifter means connected in series with said starting winding for shifting the current phase in said starting winding with respect to the main winding; magnetic data head means including at least one data head having aerodynamic lift characteristics and mounted for movement toward and away from said surface into and out of said boundary layer; and actuator mEans mounted on said frame in driving relationship to said data head means for causing data head movement, said actuator means being serially connected to said starting winding and responsive to said voltage drop across said starting winding for causing said actuator means to urge said data head toward said surface.
Claim 2
Dependent Claim
187 words
Data head actuation apparatus comprising: a frame; a magnetic memory device rotatably mounted on said frame and having a magnetizable surface; a rotary motor mounted on said frame and connected to said memory device for rotating said memory device at a running speed to create an air boundary layer at said surface, said rotary motor including an unimpeded main motor winding and a starting winding, the voltage drop across said starting winding being a function of motor speed, phase shifter means connected in series with said starting winding for shifting the current phase in said starting winding with respect to the main winding; magnetic data head means including at least one data head having aerodynamic lift characteristics and mounted for movement toward and away from said surface into and out of said boundary layer; and actuator mEans mounted on said frame in driving relationship to said data head means for causing data head movement, said actuator means being serially connected to said starting winding and responsive to said voltage drop across said starting winding for causing said actuator means to urge said data head toward said surface.
Claim 3
Dependent Claim
39 words
The apparatus of claim 1 wherein: said actuator means comprises a solenoid having a coil and an armature plunger, said plunger being in driving relationship to said data head means, said coil being connected to said motor circuit means.
Claim 4
Dependent Claim
39 words
The apparatus of claim 2 wherein said actuator means includes: a driving plate mounted on said armature plunger; and and adjustment screw mounted on said driving plate, said adjustment screw being in driving engagement with said data head means.
Claim 5
Dependent Claim
64 words
The apparatus of claim 3 wherein said data head means comprises: a spring having first and second ends, said first end being mounted on said frame, said data head being mounted on said second end, said adjustment screw being in abutment engagement with said spring intermediate said ends for causing resilient deflection of said spring whereby said data head is moved toward said surface.
Claim 6
Dependent Claim
61 words
The apparatus of claim 4 including: a plurality of said springs, each of said springs carrying said data head; and a corresponding plurality of said adjustment screws mounted on said driving plate and in engagement with respective said springs so that, upon solenoid actuation, said plurality of springs is deflected and such plurality of data heads is urged toward said surface.
Claim 7
Dependent Claim
70 words
The apparatus of claim 1 wherein: said phase shifter means comprises a capacitor serially connected with said starting winding; and said actuator means comprises a solenoid having a coil and an armature plunger, said plunger being in driving relationship to said data head means, said solenoid coil being connected in series with said auxiliary winding and in parallel with said capacitor so that said solenoid is responsive to said voltage.
Claim 8
Dependent Claim
86 words
The apparatus of claim 6 wherein: a relay having a relay coil is connected in series with said starting winding and said capacitor so that said starting winding is serially unimpeded, except for said relay coil and said capacitor, said relay having normally open contacts in series with said solenoid coil, said relay being operable to close said contacts for operative connection of said solenoid coil to said circuit means when the speed of said motor is sufficient to cause aerodynamic flight of said data head.
Claim 9
Dependent Claim
48 words
The apparatus of claim 7 wherein said motor circuit means comprises: a diode and a resistor in series with said solenoid coil; and a capacitor in parallel with said solenoid coil, said resistor and said capacitor having sufficient time constant to delay full energization of said solenoid coil.
Claim 10
Dependent Claim
39 words
The apparatus of claim 8 wherein said actuator means includes: a driving plate mounted on said armature plunger; and an adjustment screw mounted on said driving plate, said adjustment screw being in driving engagement with said data head means.
Claim 11
Dependent Claim
64 words
The apparatus of claim 9 wherein said data head means comprises: a spring having first and second ends, said first end being mounted on said frame, said data head being mounted on said second end, said adjustment screw being in abutment engagement with said spring intermediate said ends for causing resilient deflection of said spring whereby said data head is moved toward said surface.
Claim 12
Dependent Claim
61 words
The apparatus of claim 10 including: a plurality of said springs, each of said springs carrying said data head; and a corresponding plurality of said adjustment screws mounted on said driving plate and in engagement with respective said springs so that, upon solenoid actuation, said plurality of springs is deflected and such plurality of data heads is urged toward said surface.
Claim 13
Dependent Claim
51 words
The apparatus of claim 11 wherein: a Second resistance is connected in series with said solenoid coil; and a control switch is connected in parallel with said second resistance, said control switch being connected to be closed when said data head approaches said surface to increase energization of said solenoid coil.
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) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |