MAGNETIC HEAD

• US 3,843,968 A
• Filed: 10/24/1973
• Issued: 10/22/1974
• Est. Priority Date: 06/25/1971
• Status: Expired due to Term

• Current Assignee: William L. Kroon
• Original Assignee: William L. Kroon
• Inventors: Kroon, William L.
• Primary Examiner(s): Eddleman, Alfred H.
• Application Number:
  US05/409,045
• Time in Patent Office: 363 Days
• Field of Search: 179/1.2C 340/174.1F 346/74MC 360/121,123,125
• US Class Current: 360/121
• CPC Class Codes: G11B 5/29 Structure or manufacture of unitary devices formed of plural heads for more than one track G11B5/33, G11B5/49 and subgroups take precedence; in thin film structure G11B5/31
• CPC Class Codes: G11B 5/295 Manufacture

Abstract

A multitrack magnetic head assembly is described in which magnetic ferrite pole tips are held in place at the transducing face of the assembly by a ceramic material to which the ferrite pole pieces are glass bonded. This face part is in turn secured to a core housing carrying a plurality of core members and coil means disposed to complete the magnetic circuit through the ferrite pole pieces. As magnetic ferrite materials have many characteristics similar to the ceramic material, the face part composed of these two substances becomes a structure of high physical integrity capable of lasting under the abusive conditions of high magnetic tape speeds. Also, a method of constructing this head assembly is provided in which the ceramic face part is comprised of two half portions each carrying a set of ferrite pole pieces glass bonded therein such that the ceramic half portions can be assembled with a layer of nonmagnetic material disposed therebetween to form the transducing gaps between each associated pair of ferrite pole pieces. Once the face part portions are assembled and secured, this sub-assembly is mounted on the core housing, also of ceramic material, in such a way that the core members are arranged in the core housing to engage the ferrite pole pieces.

Claims

1. A multichannel magnetic head assembly comprising a head face part of nonglassy refractory ceramic material, having a hardness comparable to that of ferrite materials, said face part having a plurality of spaced parallel slots, a plurality of separate ferrite pole pieces mounted and glass bonded in said slots, said face part being formed of two identical half portions, a layer of nonmagnetic material deposited on one corresponding side of each said identical half portion, said half portions being assembled with said corresponding sides in abutting relation along a gap line provided by said layer of non-magnetic material separating said face part portions and associated pole pieces, a core housing having a surface receiving said face part in mated secured engagement, and a plurality of magnetic core members having coil means mounted in said core housing to register with and engage portions of said pole pieces thereby forming a plurality of magnetic transducers.

2. The head assembly as defined in claim 1 further comprising a plurality of intercore magnetic shields mounted in said core housing between each adjacent pair of core members, said shield members not extending beyond said core housing.

3. The head assembly as defined in claim 1 further comprising, a plurality of intercore magnetic shields mounted in said core housing between each adjacent pair of core members, and a corresponding plurality of shield parts mounted in said face part portions between each adjacent pair of associated pole pieces, said shield parts being arranged to engage the corresponding shields carried by said core housing when said face part is in mated secured engagement therewith.

4. The head assembly of claim 1 further defined by said ceramic face part and ferrite pole pieces and the glass bond therebetween all having coefficients of thermal expansion selected to fall within the same range.

5. The head assembly as defined in claim 1, said face part having at least one tie-bar slot intercepting both half portions and a tie-bar mounted and bonded in said slot to secure said housing portions in assembled relation.

6. The head assembly as defined in claim 1, the engaged surfaces of said face part and core housing being generally planar and such face part surface having a V-shaped groove underlying said gap line, a wedge shaped member of ceramic material matingly disposed and bonded in said groove to reinforce said face part portions at said nonmagnetic gap.