Magnetic field generator for MRI, method for assembling the same, and method for assembling a magnet unit for the same

• US 6,336,989 B1
• Filed: 08/04/1999
• Issued: 01/08/2002
• Est. Priority Date: 08/06/1998
• Status: Expired due to Term

• Current Assignee: Sumitomo Seika Chemicals Company Limited
• Original Assignee: Sumitomo Seika Chemicals Company Limited
• Inventors: Aoki, Masaaki, Hashimoto, Shigeo
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Tolin, Michael A.
• Application Number:
  US09/366,563
• Time in Patent Office: 888 Days
• Field of Search: 156/275.7, 156/293, 156/297, 294/67, 294/68, 335/297, 335/301, 335/304, 335/306, 324/318, 324/319
• US Class Current: 156/275.7
• CPC Class Codes: G01R 33/3802 Manufacture or installation of magnet assemblies; Additional hardware for transportation or installation of the magnet assembly or for providing mechanical support to components of the magnet assembly
• CPC Class Codes: G01R 33/3806 Open magnet assemblies for improved access to the sample, e.g. C-type or U-type magnets
• CPC Class Codes: G01R 33/383 using permanent magnets
• CPC Class Codes: Y10T 156/1089 of discrete laminae to single face of additional lamina
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/49075 including permanent magnet or core
• CPC Class Codes: Y10T 29/49901 Sequentially associating parts on stationary aligning means
• CPC Class Codes: Y10T 29/49902 by manipulating aligning means

Abstract

A plate yoke has an upper surface formed with a projection and a guiding rail. A new magnet block is transported by sliding on the upper surface of the plate yoke, and is bonded side by side with the projection or a magnet block which is already fixed. During the above operation, a magnetic member is held above the plate yoke. Preferably, the new magnet block is transported toward a corner portion, with side surfaces of the magnet block held parallel to a side surface of the projection and a side surface of the guiding rail respectively. When the magnet unit and the column yoke is connected, the column yoke or the magnet unit is lowered so that a guiding rod attached to an end face of the column yoke is inserted into a hole formed in the magnetic unit. Further, the column yoke is guided by a guiding member disposed between a permanent magnet on the plate yoke and a position where the column yoke is to be connected on the plate yoke.

Claims

1. A method for assembling a magnet unit by bonding magnet blocks to a bonding object provided on a surface of a plate yoke, comprising:

an applying step in which adhesive is applied to at least one of a side surface of the bonding object and a side surface of the magnet block;

a transporting step in which the magnet block is transported by sliding on the plate yoke; and

a bonding step in which the transported magnet block is bonded to the bonding object.

2. The method according to claim 1, wherein the transporting step includes a sub-step of transporting the magnet block to fit into a corner portion formed by side surfaces of a plurality of the magnet blocks.

3. The method according to claim 2, wherein the method further comprises a step of transporting the magnet block toward the corner portion, with the side surface of the magnet block held parallel to a side surface of the bonding object forming the corner portion.

4. The method according to claim 1, wherein the method further comprises a placing step in which a first guiding member is placed on the surface of the plate yoke;

and

wherein the transporting step includes a sub-step of positioning the magnet block by fitting the magnet block to a side surface of the first guiding member.

5. The method according to claim 4, wherein the transporting step includes a sub-step of transporting the magnet block to fit into a corner portion formed by the side surface of first guiding member and the side surface of the bonding object.

6. The method according to claim 5, wherein the method further comprises a step of transporting the magnet block toward the corner portion, with a side surface of the magnet block held parallel to the side surface of first guiding member forming the corner portion or the side surface of the bonding object forming the corner portion.

7. The method according to one of claims 4 to 6, wherein the first guiding member is provided with a recess, the recess being formed in the side surface of the first guiding member at a place where two magnet blocks are mutually bonded.

8. The method according to one of claims 1 to 6, wherein the bonding object includes at least one of a projection provided in the surface of the plate yoke and a magnet block already fixed in the surface of the plate yoke.

9. The method according to claim 8, wherein the projection is made of non-magnetic material.

10. A method for assembling a magnet unit by disposing a plurality of magnet blocks with a same magnetic pole facing upward in a surface of a plate yoke, comprising steps of:

disposing a magnetic member above the plate yoke at a predetermined distance from the plate yoke generally in parallel thereto; and

transporting each of the plurality of magnet blocks on the plate yoke, and fixing each of the plurality of magnet blocks to adjacent magnet blocks by bonding.

11. The method according to claim 10, wherein the magnetic member is a pole piece, and the method further comprises a step of lowering the pole piece to place the pole piece onto the disposed magnet blocks after the step of fixing the magnet blocks.