EP0301737A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method of, and an apparatus for, retracting the head and braking the drive motor of a record disk file
Assignee: International Business Machines Corp
•
Filing: 1988-07-18
•
Granted: —
•
Expires: 2008-07-18
Abstract
Abstract One phase (A) of a multi-phase spindle motor (10), normally used to rotate the disk of a record disk file when power is on, is used to supply power to a capacitor storage circuit (50) when power is lost (by being turned off or otherwise interrupted). The capacitor storage circuit (50) provides the power to a head retract circuit (90), which retracts the head. The combination of the generator effect of the phase (A) and the capacitor storage circuit (50) provides power to the retract circuit (90) for a time sufficient to reliably retract and lock the head regardless of the bias of the head prior to power loss. Simultaneously with one phase (A) of the motor being used to retract the head, the other phases (B, C) of the motor are shorted together to provide regenerative braking. Preferably, the capacitor storage circuit is used as a line filter circuit when power is on.
Inventors
- 👤 Charles Christian Hanson
- 👤 Michael Joseph Ross
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 19:32
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; G11B19/02; G11B19/04; G11B19/22; G11B21/00; G11B21/02; G11B21/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
63 words
A method of retracting a head assembly of a disk file driven by a multi-phase spindle motor and of braking the motor upon loss of power to the disk file, the method comprising generating power with one phase of the multi-phase spindle motor to retract the head assembly; and simultaneously shorting the remaining phases of the multi-phase motor to regeneratively brake the motor.
Claim 2
Independent Claim
63 words
A method of retracting a head assembly of a disk file driven by a multi-phase spindle motor and of braking the motor upon loss of power to the disk file, the method comprising generating power with one phase of the multi-phase spindle motor to retract the head assembly; and simultaneously shorting the remaining phases of the multi-phase motor to regeneratively brake the motor.
Claim 3
Dependent Claim
37 words
A method as claimed in claim 1, further comprising: storing power in a storage circuit to retract the head assembly; and using the power generated with the one phase of the motor to recharge said storage circuit.
Claim 4
Independent Claim
91 words
An apparatus for retracting a head assembly of a disk file driven by a multi-phase spindle motor and of braking the motor upon loss of power to the disk file, the apparatus comprising: head retract means connected to the head assembly and responsive to an energization signal to retract the head assembly control means, connected to the spindle motor, for driving the motor upon an indication of the presence of power, and for simultaneously producing said energization signal and for braking the motor upon an indication of the loss of power.
Claim 5
Independent Claim
91 words
An apparatus for retracting a head assembly of a disk file driven by a multi-phase spindle motor and of braking the motor upon loss of power to the disk file, the apparatus comprising: head retract means connected to the head assembly and responsive to an energization signal to retract the head assembly control means, connected to the spindle motor, for driving the motor upon an indication of the presence of power, and for simultaneously producing said energization signal and for braking the motor upon an indication of the loss of power.
Claim 6
Dependent Claim
31 words
An apparatus as claimed in claim 3, further comprising: storage means, connected to the control means and the head retract means, for storing the energization signal produced by the control means.
Claim 7
Dependent Claim
103 words
An apparatus as claimed in claim 4, wherein the control means comprises: a first plurality of switching devices each having a first, second and third input, the first inputs being connected to indication means for indicating the presence and loss of power, the second inputs being connected to the motor, and the third inputs being connected to the storage means; and a second plurality of switching devices each having a first, second and third input, the first inputs being connected to the indication means, the second inputs being connected to the motor, and the third inputs being connected to a ground signal level.
Claim 8
Dependent Claim
49 words
An apparatus as claimed in claim 5, wherein the first plurality of switching devices, upon an indication of the presence of power on from the indication means, sequentially switch on and off to provide sequential power to each phase of the motor, thereby producing rotational motion of the motor.
Claim 9
Dependent Claim
50 words
An apparatus as claimed in claim 5, wherein one of the first plurality of switching devices is held on upon an indication of loss of power from the indication means, thereby providing an electrical path between a first phase of the motor to the storage means for the energization signal.
Claim 10
Dependent Claim
39 words
An apparatus as claimed in claim 5, wherein the second plurality of switching devices, upon an indication of the presence of power, from the indication means, sequentially switch on and off to provide speed control information to the motor.
Claim 11
Dependent Claim
49 words
An apparatus as claimed in claim 5, wherein at least two of the second plurality of switching devices are held on upon an indication of loss of power, from the indication means, thereby shorting out all phases except the first phase of the motor, thereby regeneratively braking the motor.
Claim 12
Independent Claim
24 words
An apparatus as claimed in any of claims 4 to 9, wherein the storage means comprises a filter having a capacitor and an inductor.
Claim 13
Independent Claim
38 words
An apparatus as claimed in any of claims 4 to 9, wherein the capacitor provides the energization signal to the retract means upon an indication of power loss and is recharged by the first phase of the motor.
Claim 14
Dependent Claim
29 words
An apparatus as claimed in claim 10 or claim 11, wherein the filter filters the sequential power upon an indication of the presence of power from the indicating means.
Claim 15
Dependent Claim
236 words
A record disk file having a head assembly, comprising: a spindle motor having three phases; a first plurality of switching devices, connected to the spindle motor; a second plurality of switching devices, connected to the spindle motor; a filter, connected to the first plurality of switching devices; power indication means, connected to the first and second plurality of switching devices; head retract means, connected to the filter, for retracting the head assembly in response to an energization signal; the first plurality of switching devices, upon indication from the indication means of the presence of power, sequentially switching on and off to provide sequential power to each phase of the motor, thereby producing rotational motion of the motor, wherein one of the first plurality of switching devices is held on upon indication from the indication means of loss of power, thereby providing an electrical path between a first phase of the motor to the filter for the energization signal to energize the head retract means; and the second plurality of switching devices upon indication from the indication means of the presence of power, sequentially switching on and off to provide speed control information to the motor, wherein at least two of the second plurality of switching devices are held on upon indication from the indication means of loss of power, thereby shorting out all phases except the first phase of the motor to regeneratively brake the motor.
Claim 16
Dependent Claim
236 words
A record disk file having a head assembly, comprising: a spindle motor having three phases; a first plurality of switching devices, connected to the spindle motor; a second plurality of switching devices, connected to the spindle motor; a filter, connected to the first plurality of switching devices; power indication means, connected to the first and second plurality of switching devices; head retract means, connected to the filter, for retracting the head assembly in response to an energization signal; the first plurality of switching devices, upon indication from the indication means of the presence of power, sequentially switching on and off to provide sequential power to each phase of the motor, thereby producing rotational motion of the motor, wherein one of the first plurality of switching devices is held on upon indication from the indication means of loss of power, thereby providing an electrical path between a first phase of the motor to the filter for the energization signal to energize the head retract means; and the second plurality of switching devices upon indication from the indication means of the presence of power, sequentially switching on and off to provide speed control information to the motor, wherein at least two of the second plurality of switching devices are held on upon indication from the indication means of loss of power, thereby shorting out all phases except the first phase of the motor to regeneratively brake the motor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.