Magnetic memory disc pack balancing system

Claim 1

A method for constructing a memory disc assembly comprising: forming a hub member with a plurality of holes extending completely therethrough, said hub member being formed with a peripheral flange and said holes being formed in a central region closer to the center of the hole than the flange; forming internal threads along the walls of said holes; assemblying a stack of memory discs coaxially with said hub and with one end of the stack held against the flange of the hub; assemblying a clamp with a peripheral portion and a central portion that has holes therethrough so the peripheral portion lies over an end of the stack opposite the flange of the hub and the central portion lies facewise against the central hub region and with the holes of the clamp and hub member aligned; inserting a plurality of screws that are shorter than the combined thicknesses of the clamp and hub member through the holes of the clamp and screwing them into the threaded holes of the hub; rotating the assembled hub member, clamp and stack of memory discs while measuring the direction and amount of imbalance; screwing at least one headless screw into one of said threaded holes in the hub member from the face of the hub member opposite the clamp to substantially balance at least the portion of the assembly nearest the hub member, said screw being screwed far enough so all of it lies within the threaded hole; and deforming the threads of the hole containing the headless screw at a location near the end of the hole that lies opposite the clamp.

Claim 2

A method for constructing a memory disc assembly comprising: forming a hub member with a plurality of holes extending completely therethrough, said hub member being formed with a peripheral flange and said holes being formed in a central region closer to the center of the hole than the flange; forming internal threads along the walls of said holes; assemblying a stack of memory discs coaxially with said hub and with one end of the stack held against the flange of the hub; assemblying a clamp with a peripheral portion and a central portion that has holes therethrough so the peripheral portion lies over an end of the stack opposite the flange of the hub and the central portion lies facewise against the central hub region and with the holes of the clamp and hub member aligned; inserting a plurality of screws that are shorter than the combined thicknesses of the clamp and hub member through the holes of the clamp and screwing them into the threaded holes of the hub; rotating the assembled hub member, clamp and stack of memory discs while measuring the direction and amount of imbalance; screwing at least one headless screw into one of said threaded holes in the hub member from the face of the hub member opposite the clamp to substantially balance at least the portion of the assembly nearest the hub member, said screw being screwed far enough so all of it lies within the threaded hole; and deforming the threads of the hole containing the headless screw at a location near the end of the hole that lies opposite the clamp.

Claim 3

A method for balancing memory disc packs which each include a hub portion and at least one memory disc fixed to the hub portion; comprising: forming a plurality of uniformly spaced threaded holes in the hub portion of each memory disc pack; rotating each of the memory disc packs which have said threaded holes therein on a balancing machine to determine the direction and amount of imbalance of each diSc pack; and screwing a plurality of screws into a plurality of said threaded holes of at least some of said memory disc packs to balance them; and wherein said threaded holes are circumferentially spaced 60* from one another; each of said screws has either of two predetermined masses wherein one predetermined mass L is larger than the other mass S; and said screws are installed in selected of said holes A, B and C with hole B lying between and spaced 60* from each of the holes A and C, to provide approximately the same balancing correction as would be supplied by a concentrated weight substantially in accordance with the following table:

Claim 4

A method for balancing memory disc packs which each include a hub portion and at least one memory disc fixed to the hub portion; comprising: forming a plurality of uniformly spaced threaded holes in the hub portion of each memory disc pack; rotating each of the memory disc packs which have said threaded holes therein on a balancing machine to determine the direction and amount of imbalance of each diSc pack; and screwing a plurality of screws into a plurality of said threaded holes of at least some of said memory disc packs to balance them; and wherein said threaded holes are circumferentially spaced 60* from one another; each of said screws has either of two predetermined masses wherein one predetermined mass L is larger than the other mass S; and said screws are installed in selected of said holes A, B and C with hole B lying between and spaced 60* from each of the holes A and C, to provide approximately the same balancing correction as would be supplied by a concentrated weight substantially in accordance with the following table:

Claim 5

A method for constructing a memory disc assembly with a hub portion and a memory disc fixed to the hub portion, comprising: forming a hub portion with a pair of members which have adjacent face portions; forming a plurality of aligned axially extending holes in said members; threading said holes; attaching a memory disc to said hub portion; rotating said hub portion and disc on a balancing machine to determine the direction and amount of imbalance; and screwing at least one balancing screw in one of said threaded holes to balance said hub portion; said pair of members of said hub portion being fastened together by screwing a plurality of fastening bolts through them which are short enough to project only partially through at least one of the members; and said balancing screw being screwed into one of said members from an end opposite a fastening bolt.

Claim 6

A method for constructing a memory disc assembly with a hub portion and a memory disc fixed to the hub portion, comprising: forming a hub portion with a pair of members which have adjacent face portions; forming a plurality of aligned axially extending holes in said members; threading said holes; attaching a memory disc to said hub portion; rotating said hub portion and disc on a balancing machine to determine the direction and amount of imbalance; and screwing at least one balancing screw in one of said threaded holes to balance said hub portion; said pair of members of said hub portion being fastened together by screwing a plurality of fastening bolts through them which are short enough to project only partially through at least one of the members; and said balancing screw being screwed into one of said members from an end opposite a fastening bolt.