Patent US3842494A successfully refreshed from Google Patents.
US3842494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multichannel magnetic ferrite head and a method for making the same
Assignee: Panasonic Holdings Corp
•
Filing: 1970-02-26
•
Granted: 1974-10-22
•
Expires: 1990-02-26
Abstract
Abstract A multichannel magnetic head consisting essentially of a plurality of magnetic ferrite heads and a plurality of glass spacers filling the spaces between each pair of adjacent magnetic ferrite heads in order to bond said plurality of magnetic ferrite heads into one body. The multichannel head has a high resistance to head-wear and an excellent low cross-talk characteristic and is applicable to various types of multi-track recorders.
Inventors
- 👤 H Chiba
- 👤 E Hirota
- 👤 S Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:09
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/29; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49048; Y10T29/49055; Y10T29/49057
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
298 words
A method of making a multichannel magnetic head comprising forming two hollows in each of a pair of ferrite blocks, a laterally opening hollow opening out of one surface of each block and a hollow opening out of a surface of each block which is perpendicular to said one surface; polishing the pairs of surfaces on opposite sides of said laterally opening hollows in each block; bonding the pair of said hollowed and polished ferrite blocks by glass bonding the corresponding polished surfaces to each other so as to form two magnetic gaps; forming a plurality of grooves through the bonded blocks transversely to the bonded surfaces so as to form a plurality of head tips, said plurality of grooves being substantially equidistantly spaced along the blocks and each having the same size; heating the bonded blocks having said plurality of grooves formed therethrough; filling said plurality of grooves with molten glass to form a plurality of glass spacers; cutting one side of said bonded blocks in a plane parallel to the bottom face of said plurality of grooves to leave a series of head elements separated by glass spacers and each having an inner leg and an outer leg on each side of the plane of the magnetic gaps; shaping the side of the bonded blocks opposed to said one side so as to have a convex surface which acts as a tape engaging surface; dividing the shaped blocks into multichannel magnetic head elements, each of which includes a plurality of head tips; attaching to an inner leg on one side and an outer leg on the other side of each head tip a back-core having windings wound thereon; and attaching the back-cores in adjacent head tips in positions offset from each other transversely of said hollows.
Claim 2
Independent Claim
298 words
A method of making a multichannel magnetic head comprising forming two hollows in each of a pair of ferrite blocks, a laterally opening hollow opening out of one surface of each block and a hollow opening out of a surface of each block which is perpendicular to said one surface; polishing the pairs of surfaces on opposite sides of said laterally opening hollows in each block; bonding the pair of said hollowed and polished ferrite blocks by glass bonding the corresponding polished surfaces to each other so as to form two magnetic gaps; forming a plurality of grooves through the bonded blocks transversely to the bonded surfaces so as to form a plurality of head tips, said plurality of grooves being substantially equidistantly spaced along the blocks and each having the same size; heating the bonded blocks having said plurality of grooves formed therethrough; filling said plurality of grooves with molten glass to form a plurality of glass spacers; cutting one side of said bonded blocks in a plane parallel to the bottom face of said plurality of grooves to leave a series of head elements separated by glass spacers and each having an inner leg and an outer leg on each side of the plane of the magnetic gaps; shaping the side of the bonded blocks opposed to said one side so as to have a convex surface which acts as a tape engaging surface; dividing the shaped blocks into multichannel magnetic head elements, each of which includes a plurality of head tips; attaching to an inner leg on one side and an outer leg on the other side of each head tip a back-core having windings wound thereon; and attaching the back-cores in adjacent head tips in positions offset from each other transversely of said hollows.
Claim 3
Dependent Claim
35 words
A method for making a multichannel magnetic head as claimed in claim 1 further comprising cutting off the inner leg and outer leg of each head element to which said back core is not attached.
Claim 4
Dependent Claim
47 words
A method of making a multichannel magnetic head as claimed in claim 1 further comprising inserting a thin ferrite plate into each of said plurality of grooves in a position parallel to the groove, and thereafter filling the grooves with molten glass which surrounds said thin plates.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |