Crowned disc clamp

1. A disc clamp for securing a data storage disc to a drive motor, the disc clamp comprising.

a generally disc-shaped body comprising:

a central portion adapted to be secured to the drive motor;

a raised portion extending around the central portion;

a contact portion extending around the raised portion having a bottom contact surface for pressing on a disc to secure the disc to a drive motor; and

an upwardly extending outer rim of the contact portion having means for decreasing a pressure differential around the contact portion between the disc and the bottom contact surface of the disc clamp pressing on the disc.

2. The disc clamp of claim 1 , wherein the means for decreasing comprises projections spaced apart around the rim.

3. The disc clamp of claim 2 , wherein the projections comprise at least fifteen projections.

4. The disc clamp of claim 3 , wherein the at least fifteen projections comprises at least twenty-four projections.

5. The disc clamp of claim 1 , wherein the rim extends up and radially in to define a channel that is adapted to receive a balance ring.

6. The disc clamp of claim 1 , wherein the body comprises stainless steel.

7. The disc clamp of claim 1 , wherein the raised portion defines spanner slots that are adapted to receive locating members.

8. The disc clamp of claim 7 , wherein the spanner slots include three radially extending spanner slots.

9. A disc drive having a disc pack assembly, the disc pack assembly comprising:

a data storage disc;

a disc clamp securing the data storage disc to a spindle motor hub, the disc clamp having a generally disc-shaped body comprising:

a central portion secured to the hub;

a raised portion extending around the central portion; and

a contact portion extending around the raised portion and pressing down on the disc to secure the disc to the hub, the contact portion also having an upwardly extending rim defining an annular channel, wherein the rim has at least fifteen spaced apart upwardly extending tabs positioned around the rim; and

a balance ring seated in the annular channel.

10. The disc drive of claim 9 , wherein the tabs are substantially rectangular.

11. The disc drive of claim 9 , wherein the at least fifteen tabs comprises at least twenty-four tabs.

12. The disc drive of claim 9 , wherein the rim extends up and radially in to define the channel.

13. The disc drive of claim 9 , wherein the body comprises stainless steel.

14. The disc drive of claim 9 , wherein the balance ring is a spring wire having first and second ends and defining a gap between the first and second ends.

15. The disc drive of claim 9 , wherein the raised portion defines spanner slots that are adapted to receive locating members.

16. A disc clamp assembly for securing a data storage disc to a drive motor in a disc drive, the assembly comprising:

a disc clamp for securing a data storage disc to a drive motor, the disc clamp comprising:

a central portion adapted to be secured to a drive motor;

a raised portion extending around the central portion; and

a contact portion extending around the raised portion for pressing down on the disc to secure the disc to the drive motor, the contact portion also having an upwardly extending rim, wherein the rim has at least fifteen spaced apart upwardly extending projections positioned around the rim; and

a balance ring seated in the contact portion.

17. The assembly of claim 16 , wherein the projections are substantially rectangular.

18. The assembly of claim 16 , wherein the at least fifteen projections comprises at least twenty-four projections.

19. The assembly of claim 16 , wherein the rim extends up and radially in to define the channel.

20. The assembly of claim 16 , wherein the body comprises stainless steel.

21. The assembly of claim 16 , wherein the balance ring is a spring wire having first and second ends and defining a gap between the first and second ends.

22. The assembly of claim 16 , wherein the raised portion defines spanner slots that are adapted to receive locating members.