Patent US4240121A successfully refreshed from Google Patents.
US4240121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband magnetic tape transducer head
Assignee: Robert Bosch GmbH
•
Filing: 1979-01-18
•
Granted: 1980-12-16
•
Expires: 1999-01-18
Abstract
Abstract To reduce the inductance of a ferrite transducer head, the head is formed of ferrite-type pole pieces laterally extended by non-magnetic material of high wear resistance characteristic to decrease the per-unit application pressure of the tape against the overall head, the pole pieces being connected by a yoke of cross section which is small with respect to that of the pole pieces, the signal transducing coil being wound on the yoke. To provide space for winding of the coil, the pole pieces are formed with recess openings, and the extending non-magnetic support elements are likewise formed with an opening to provide space for the coil. The entire head can be mounted on a support, for example by an adhesive, made of non-magnetic material.
Inventors
- 👤 Rudolf Prochnow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/255
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
155 words
Broadband magnetic tape transducer head adapted to have a magnetic tape pass over a head surface thereof to transduce signals of various frequencies comprising a pair of pole pieces (1, 1) of magnetically active homogenious material to conduct magnetic flux therein, separated by a gap (2), the extend (B) of the pole pieces, in the direction of relative movement between the head and the tape being at least three times as long as the wave length of the lowest frequency signal to be transduced, tape support elements (3) of wear-resistant, non-magnetic material located adjacent the pole pieces (1) to form an extended support surface with the pole pieces for tape engaging said head, a yoke (10) connecting said pole pieces , said yoke having a minimum cross section (E) which is small with respect to the minimum cross section (D) of the pole pieces; and a single winding (4) closely wound about said yoke (10).
Claim 2
Dependent Claim
155 words
Broadband magnetic tape transducer head adapted to have a magnetic tape pass over a head surface thereof to transduce signals of various frequencies comprising a pair of pole pieces (1, 1) of magnetically active homogenious material to conduct magnetic flux therein, separated by a gap (2), the extend (B) of the pole pieces, in the direction of relative movement between the head and the tape being at least three times as long as the wave length of the lowest frequency signal to be transduced, tape support elements (3) of wear-resistant, non-magnetic material located adjacent the pole pieces (1) to form an extended support surface with the pole pieces for tape engaging said head, a yoke (10) connecting said pole pieces , said yoke having a minimum cross section (E) which is small with respect to the minimum cross section (D) of the pole pieces; and a single winding (4) closely wound about said yoke (10).
Claim 3
Dependent Claim
21 words
Transducer head according to claim 1, wherein both the pole pieces (1) and the yoke (10) comprise highly permeable ferrite material.
Claim 4
Dependent Claim
38 words
Transducer head according to claim 1 or 2, wherein the pole pieces (1, 1) and the yoke (10) are inserted in openings formed in said tape support elements (3), said tape support elements being formed of non-magnetic material.
Claim 5
Dependent Claim
34 words
Transducer head according to claim 3, further including a support plate (7) secured to said tape support element (3) and supporting both said tape support elements and said pole pieces (1, 1) and yoke.
References Cited (Backward Citations)
US3244818A
Cited
US3303292A
Cited
US3535466A
Cited
US3582572A
Cited
US3651278A
Cited
US3987487A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |