US3851375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of bonding together mouldings of sintered oxidic ferromagnetic material
Assignee: US Philips Corp
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Filing: 1974-02-11
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Granted: 1974-12-03
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Expires: 1994-02-11
Abstract
Abstract In manufacturing in particular multi-channel magnetic heads, it is usual to place two ferrite blocks on each other with the interposition of spacing members, to cause glass to flow into the resulting space during a first bonding step, to make grooves in the resulting assembly, and to cement therein filling members with glass during a second bonding step. This method has several drawbacks which are avoided by producing a connection between the ferrite blocks and the spacing members prior to performing further operations, which connection fixes the ferrite blocks relative to each other.
Inventors
- 👤 J Koorneef
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:20
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; Y10T29/49036; Y10T29/49041; Y10T29/49048; Y10T29/49053; Y10T29/49055
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A METHOD OF BONDING TOGETHER A PLURALITY OF MOULDINGS OF A SINTERED OXIDIC FERROMAGNETIC MATERIAL COMPRISING THE STEPS OF: A. PLACING A METALLIC SPACING MEMBER COMPOSED OF A LEADTIN ALLOY BETWEEN SAID MOULDINGS; B. HEATING THE RESULTING ASSEMBLY OF (A) TO A TEMPERATURE BETWEEN APPROXIMATELY 145*C AND 165*C FOR A PERIOD BETWEEN APPROXIMATELY 1 AND 10 MINUTES; C. CONCURRENTLY WITH THE HEATING STEP OF (B), SUBJECTING SAID ASSEMBLY TO A MECHANICAL PRESSURE BETWEEN APPROXIMATELY 50 AND 150 KG/SQ.CM., UNTIL SAID SPACING MEMBER AND SAID MOULDINGS ARE BONDED TOGETHER; AND D. COOLING SAID ASSEMBLY AND REMOVING SAID PRESSURE.
Claim 2
Independent Claim
97 words
A METHOD OF BONDING TOGETHER A PLURALITY OF MOULDINGS OF A SINTERED OXIDIC FERROMAGNETIC MATERIAL COMPRISING THE STEPS OF: A. PLACING A METALLIC SPACING MEMBER COMPOSED OF A LEADTIN ALLOY BETWEEN SAID MOULDINGS; B. HEATING THE RESULTING ASSEMBLY OF (A) TO A TEMPERATURE BETWEEN APPROXIMATELY 145*C AND 165*C FOR A PERIOD BETWEEN APPROXIMATELY 1 AND 10 MINUTES; C. CONCURRENTLY WITH THE HEATING STEP OF (B), SUBJECTING SAID ASSEMBLY TO A MECHANICAL PRESSURE BETWEEN APPROXIMATELY 50 AND 150 KG/SQ.CM., UNTIL SAID SPACING MEMBER AND SAID MOULDINGS ARE BONDED TOGETHER; AND D. COOLING SAID ASSEMBLY AND REMOVING SAID PRESSURE.
Claim 3
Dependent Claim
190 words
In the method of bonding together a plurality of mouldings of sintered oxidic ferromagnetic material by placing a metallic spacing member between said mouldings defining therewith a gap space, thermo-compression bonding said mouldings to said spacing member to form a rigid assembly and then placing non-magnetizable bonding material on said assembly on the outside of said gap space and heating said assembly and said bonding materiaL to cause said bonding material to flow into said gap space by capillary action, and thereafter cooling said bonding material to solidify it, the improvement comprising heating the assembly comprising said mouldings and said spacing member to a temperature below the melting temperature of said spacing member and, concurrently with said heating step, subjecting said assembly to a maximum mechanical pressure of approximately 150 kg/sq.cm. until said spacing member and said mouldings are bonded together; cooling said assembly; removing said pressure; placing non-magnetizable bonding material on the outside of said gap space; and reheating said assembly and bonding material to a temperature at which said bonding material melts and flows into said gap space but less than said melting temperature of said spacing member.
Claim 4
Dependent Claim
190 words
In the method of bonding together a plurality of mouldings of sintered oxidic ferromagnetic material by placing a metallic spacing member between said mouldings defining therewith a gap space, thermo-compression bonding said mouldings to said spacing member to form a rigid assembly and then placing non-magnetizable bonding material on said assembly on the outside of said gap space and heating said assembly and said bonding materiaL to cause said bonding material to flow into said gap space by capillary action, and thereafter cooling said bonding material to solidify it, the improvement comprising heating the assembly comprising said mouldings and said spacing member to a temperature below the melting temperature of said spacing member and, concurrently with said heating step, subjecting said assembly to a maximum mechanical pressure of approximately 150 kg/sq.cm. until said spacing member and said mouldings are bonded together; cooling said assembly; removing said pressure; placing non-magnetizable bonding material on the outside of said gap space; and reheating said assembly and bonding material to a temperature at which said bonding material melts and flows into said gap space but less than said melting temperature of said spacing member.
Claim 5
Dependent Claim
69 words
The method of claim 2, wherein the metallic spacing member is of readily electrically conducting metal, and said bond with the mouldings is produced by heating the assembly to a temperature wherein the sintered oxidic ferromagnetic material of the mouldings becomes slightly electrically conductive, but below the melting point of said spacing member, and then conveying a small electric current from the electrically conductive spacing member to the mouldings.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |