I claim:
1. A sifter dispensing cap base for attachment to a package containing material to be dispensed, comprising:
(a) a vertical cylindrical shell portion;
(b) a web portion covering an upper end of said vertical cylindrical shell portion;
(c) said web portion including a flap, opening of said flap permitting access to said material; and
(d) said flap including a living hinge disposed along one edge thereof.
2. A sifter dispensing cap base, as defined in claim 1, further comprising: a first stop mechanism disposed in said sifter dispensing cap base to prevent said flap from protruding substantially into an opening created by downward and inward pressing of said flap to create an opening in said web.
3. A sifter dispensing cap base, as defined in claim 1, further comprising: a second stop mechanism disposed in said sifter dispensing cap base to limit inward travel of said flap.
4. A sifter dispensing cap base, as defined in claim 1, wherein: said living hinge is arcuate and pressing said flap downwardly and inwardly causes said flap to toggle and said flap will remain in a downward and inward position by virtue of causing said flap to toggle.
5. A sifter dispensing cap base, as defined in claim 2, wherein: said first stop mechanism comprises at least one door stop depending from an inner surface of said web and extending inwardly from an inner surface of a vertical circular ring disposed around an upper edge of said cylindrical shell portion.
6. A sifter dispensing cap base, as defined in claim 3, wherein: said second stop mechanism comprises a governor bar depending from an inner surface of said web and extending across a vertical circular ring disposed around an upper edge of said cylindrical shell portion.
7. A sifter dispensing cap assembly, comprising:
(a) a fixed base for attachment to a package containing material to be dispensed;
(b) said fixed base including a cylindrical shell portion, with inner and outer vertical cylindrical rings extending upwardly from an upper edge of said cylindrical shell portion and defining therebetween a circular groove;
(c) a rotatable cap disposed on said fixed base and selectively movable between a plurality of positions with respect to said fixed base;
(d) a tongue depending from an inner surface of said rotatable cap and inserted in said circular groove such that said tongue moves in said circular groove as said rotatable cap is rotated with respect to said fixed base; and
(e) a plurality of traps disposed in said circular groove and engagable with said tongue, such that said rotatable cap can be lightly held in a selected one of said plurality of positions.
8. A sifter dispensing cap assembly, as defined in claim 7, wherein:
(a) each of said traps has first and second end portions sloping upwardly from a bottom of said circular groove to spaced apart first and second peaks; and
(b) each of said traps has a lower central portion disposed between said first and second spaced apart peaks, said lower central portion being engagable by a lower end of said tongue to lightly hold said rotatable cap in a selected one of said plurality of positions.
9. A sifter dispensing cap, comprising:
(a) a fixed base for attachment to a package containing material to be dispensed;
(b) said fixed base including a vertical cylindrical shell portion and a vertical ring extending upwardly from an upper edge of said cylindrical shell portion, said vertical ring having an outwardly extending circular locking element disposed around an upper edge of an outer surface of said vertical ring;
(c) a rotatable cap disposed on said fixed base, said rotatable cap including a vertical cylindrical shell portion having a plurality of inwardly extending, spaced apart, arcuate locking elements disposed around a lower edge of an inner surface of said vertical cylindrical shell portion; and
(d) said circular locking element and said plurality of arcuate locking elements being generally vertically disposed so as to rotatably secure said rotatable cap on said fixed base with a minimum of mutual surface engagement.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A method for detecting an abnormal fly height of a magnetic head, comprising:
reproducing a servo signal recorded on a magnetic disk utilizing said magnetic head in response to an initiation of a write operation;
determining the gain of said servo signal; and
comparing said gain with a reference value to detect an abnormal fly height of said magnetic head.
2. The method as recited in claim 1, wherein said reference value is the gain of a servo signal determined when the fly height of said magnetic head is normal.
3. The method as recited in claim 1, wherein said reference value is based on the gain of a previous servo signal.
4. The method as recited in claim 3, wherein said reference value is determined by multiplying the gain of said previous servo signal with an number greater than one.
5. The method as recited in claim 4, wherein said number is 1.1.
6. The method as recited in claim 1, wherein a separate reference value is set for each of the predetermined cylinder areas on a recording surface of said magnetic disk.
7. A method for detecting an abnormal fly height of a magnetic head, comprising:
reproducing a servo signal recorded on a magnetic disk utilizing said magnetic head in response to an initiation of a write operation;
determining the amplitude of said servo signal; and
comparing said amplitude with a reference value to detect an abnormal fly height of said magnetic head.
8. The method as recited in claim 7, wherein said reference value is the amplitude of a servo signal determined when the fly height of said magnetic head is normal.
9. The method as recited in claim 7, wherein said reference value is based on the amplitude of a previous servo signal.
10. The method as recited in claim 7, wherein a separate reference value is set for each of the predetermined cylinder areas on a recording surface of said magnetic disk.
11. A method for writing data on a magnetic disk, comprising:
reproducing a servo signal recorded on said magnetic disk utilizing a magnetic head in response to an initiation of a write operation;
determining the gain of said servo signal;
comparing said gain with a reference value to detect an abnormal fly height of said magnetic head; and
discontinuing said write operation in response to detecting an abnormal fly height of said magnetic disk.
12. The method as recited in claim 11, further comprising the step of retrying said write operation after discontinuing said write operation in response to detecting an abnormal fly height.
13. The method as recited in claim 12, further including:
changing a recording area into which data is to be written to an alternate area after retrying said write operation a predetermined number of times; and
performing said write operation on said alternate area.
14. A method for writing data on a magnetic disk, comprising:
reproducing a servo signal recorded on said magnetic disk utilizing a magnetic head in response to an initiation of a write operation;
determining the amplitude of said servo signal;
comparing said amplitude with a reference value to detect an abnormal fly height of said magnetic head; and
discontinuing said write operation in response to detecting an abnormal fly height of said magnetic disk.
15. The method as recited in claim 11, further comprising the step of retrying said write operation after discontinuing said write operation in response to detecting an abnormal fly height.
16. The method as recited in claim 12, further including:
changing a recording area into which data is to be written to an alternate area after retrying said write operation a predetermined number of times; and
performing said write operation on said alternate area.
17. A hard disk drive apparatus, comprising:
at least one rotating magnetic disk;
at least one magnetic head that records data on said magnetic disk and reproduces data recorded on said magnetic disk;
servo signal reproduction control means for causing said magnetic head to reproduce a servo signal recorded on said magnetic disk when a write operation for writing data on said magnetic disk is initiated;
an amplifier that determines the gain of said servo signal; and
abnormal fly height detection means for comparing the gain of said servo signal with a reference value to detect an abnormal fly height of said magnetic head.
18. The hard disk drive apparatus as recited in claim 17, further comprising a write operation discontinuing means for discontinuing said write operation in response to detecting an abnormal fly height of said magnetic head.
19. A hard disk drive apparatus, comprising:
at least one rotating magnetic disk;
at least one magnetic head that records data on said magnetic disk and reproduces data recorded on said magnetic disk;
servo signal reproduction control means for causing said magnetic head to reproduce a servo signal recorded on said magnetic disk when a write operation for writing data on said magnetic disk is initiated;
an amplitude detection circuit that determines the amplitude of said servo signal; and
abnormal fly height detection means for-comparing the amplitude of said servo signal with a reference value to detect an abnormal fly height of said magnetic head.
20. The hard disk drive apparatus as recited in claim 19, further comprising a write operation discontinuing means for discontinuing said write operation in response to detecting an abnormal fly height of said magnetic head.
21. The hard disk drive apparatus as recited in claim 19, wherein said amplitude detection circuit includes:
a full-wave rectifier that converts said servo signal into a DC signal;
a sample hold circuit, coupled to said full-wave rectifier, that samples said converted DC signal to obtain the amplitude of said servo signal;
a capacitor coupled to said sample hold circuit; and
a reset switch that operates to store a maximum voltage of said servo signal during a certain period of time in said capacitor.
22. A computer program product, comprising:
a computer-readable medium having stored thereon computer executable instructions for implementing a method for detecting an abnormal fly height of a magnetic head, said computer executable instructions when executed, perform the steps of:
reproducing a servo signal recorded on a magnetic disk utilizing said magnetic head in response to an initiation of a write operation;
determining the gain of said servo signal; and
comparing said gain with a reference value to detect an abnormal fly height of said magnetic head.
23. The computer program product as recited in claim 22, wherein said reference value is the gain of a servo signal determined when the fly height of said magnetic head is normal.
24. The computer program product as recited in claim 22, wherein said reference value is based on the gain of a previous servo signal.
25. A computer program product, comprising:
a computer-readable medium having stored thereon computer executable instructions for implementing a method for detecting an abnormal fly height of a magnetic head, said computer executable instructions when executed, perform the steps of:
reproducing a servo signal recorded on a magnetic disk utilizing said magnetic head in response to an initiation of a write operation;
determining the amplitude of said servo signal; and
comparing said amplitude with a reference value to detect an abnormal fly height of said magnetic head.
26. The computer program product as recited in claim 25, wherein said reference value is the amplitude of a servo signal determined when the fly height of said magnetic head is normal.
27. The computer program product as recited in claim 25, wherein said reference value is based on the amplitude of a previous servo signal.