Magnetic shunt assembly for bias field apparatus

Claim 2

For use with a bias field apparatus having parallel magnetically permeable plates and adjacent magnets for establishing a magnetic field in the volume bounded by the plates, an improved magnetic shunt assembly for adjusting the strnegth of the magnetic field comprising: a. a magnetically permeable fixed member secured to one of the plates and extending toward the other of the plates; b. a magnetically permeable movable member spaced from the plates and in sliding contact with the fixed member; and c. means for adjusting the air gap between a surface of the movable member and the other of the plates to vary the reluctance of the shunt assembly.

Claim 3

An improved magnetic shunt assembly as recited in claim 1 further including guide members extending from the one plate to the other plate for constraining movement of the movable member to a predetermined path.

Claim 4

An improved magnetic shunt assembly as recited in claim 2 wherein the guide members extend along a normal to the plates.

Claim 5

An improved magnetic shunt assembly as recited in claim 3 wherein the fixed member comprises a generally rectangular bar extending along a normal to the plates, and the movable member comprises a bar having at least one surface which remains in contact with the fixed member as the movable member is guided along the normal by the guide members.

Claim 6

An improved magnetic shunt assembly as recited in claim 4 wherein the movable member has a generally U-shaped cross-section having a bight within which the fixed member is received.

Claim 7

An improved magnetic shunt assembly as recited in claim 5 wherein the movable member further includes recesses at opposite ends thereof for receiving the guide members.

Claim 8

For use in a magnetic domain memory device having parallel, magnetically permeable plates and a pair of interposed bar magnets located near opposite edges of the magnetically permeable plates for establishing a bias field in the volume bounded by the plates and magnets, a pair of improved magnetic shunt assemblies for adjusting the strength of the bIas field in the volume, each of said assemblies being located adjacent one of the bar magnets and comprising: a. a magnetically permeable fixed member secured to one of the plates and having at least one planar surface extending along a normal to the magnetically permeaable plates; b. guide bars connecting the magnetically permeable plates along a normal to the plates; c. a magnetically permeable movable member linearally movable along the guide bars and having at least one planar surface in sliding contact with the planar surface of the fixed member; and d. means for adjusting the air gap between a surface of the fixed member and the adjacent plate to vary the reluctance of the assembly.

Claim 9

For use in a magnetic domain memory device having parallel, magnetically permeable plates and a pair of interposed bar magnets located near opposite edges of the magnetically permeable plates for establishing a bias field in the volume bounded by the plates and magnets, a pair of improved magnetic shunt assemblies for adjusting the strength of the bIas field in the volume, each of said assemblies being located adjacent one of the bar magnets and comprising: a. a magnetically permeable fixed member secured to one of the plates and having at least one planar surface extending along a normal to the magnetically permeaable plates; b. guide bars connecting the magnetically permeable plates along a normal to the plates; c. a magnetically permeable movable member linearally movable along the guide bars and having at least one planar surface in sliding contact with the planar surface of the fixed member; and d. means for adjusting the air gap between a surface of the fixed member and the adjacent plate to vary the reluctance of the assembly.

Claim 10

An apparatus as defined in claim 7 wherein the fixed member in each shunt assembly is a generally rectangular bar having its major planar surfaces extending along normals to the plates.

Claim 11

An apparatus as defined in claim 8 wherein the movable member has a generally U-shaped cross-section with the bight of the cross-section receiving the fixed member.

Claim 12

An apparatus as defined in claim 9 wherein the movable member further includes an internally threaded opening in the base of the U-shaped cross-section, the magnetically permeable plate adjacent the base includes an opening aligned with the threaded opening in the base and the adjusting means further comprises a nonmagnetic bolt having a head rotatable within but axially immovable with respect to the opening through the plate and a threaded shank extending into and mated with the internally threaded opening in the base of the movable member.