US4200895A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scanning head structure for wide band magnetic record/reproducing tape and method of its manufacture
Assignee: Robert Bosch GmbH
•
Filing: 1978-03-23
•
Granted: 1980-04-29
•
Expires: 1998-03-23
Abstract
Abstract To provide for accurate relocation of two cylindrical halves of a scanning head after diassembly, for example for replacement of scanning transducers, a cylindrical element is located adjacent a support block having a surface approximately matching the surface of the cylindrical scanning head and additionally includes bearing seats formed of cast, or molded material in engagement with the cylindrical portions in positioning the portions on the support block; the cast or molded projection may, for example, be made of cured epoxy, cast through holes in the support block and prevented from adhesion with the cylindrical parts by a separating element.
Inventors
- 👤 Arno Repp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:52
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/61
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
221 words
Scanning head structure for wide band magnetic recording/reproducing tape (11), particularly for video tape recording having a stationary cylindrical guide drum (10) formed with two cylindrical portions (12, 13) axially separated by a gap and means (14, 15) guiding the tape about a portion of the circumference of said drum in a spiral path, said drum being adapted to have a transducer head wheel rotatable therein in a plane transverse to the axis of the cylindrical drum to scan an inclined path across the tape as the tape moves over the drum; and a block-like support structure (16) separable from said drum located adjacent a portion of the surface of the drum extending axially alongside the drum and positioning the portions (12, 13) of the drum with respect to each other and having a surface facing the drum which approximately matches the drum surface, said structure being formed with openings extending therethrough and terminating at the surface thereof facing the guide drum (10); and bearing seats (17, 18, 19, 20; 21, 22, 23, 24) comprising a hardened cast, or molded material located in said openings, projecting from the surface of the block-like structure facing the drum and in engagement with the portions (12, 13) of the drum and accurately positioning said portions on and with respect to the block-like structure (16).
Claim 2
Dependent Claim
221 words
Scanning head structure for wide band magnetic recording/reproducing tape (11), particularly for video tape recording having a stationary cylindrical guide drum (10) formed with two cylindrical portions (12, 13) axially separated by a gap and means (14, 15) guiding the tape about a portion of the circumference of said drum in a spiral path, said drum being adapted to have a transducer head wheel rotatable therein in a plane transverse to the axis of the cylindrical drum to scan an inclined path across the tape as the tape moves over the drum; and a block-like support structure (16) separable from said drum located adjacent a portion of the surface of the drum extending axially alongside the drum and positioning the portions (12, 13) of the drum with respect to each other and having a surface facing the drum which approximately matches the drum surface, said structure being formed with openings extending therethrough and terminating at the surface thereof facing the guide drum (10); and bearing seats (17, 18, 19, 20; 21, 22, 23, 24) comprising a hardened cast, or molded material located in said openings, projecting from the surface of the block-like structure facing the drum and in engagement with the portions (12, 13) of the drum and accurately positioning said portions on and with respect to the block-like structure (16).
Claim 3
Dependent Claim
41 words
Structure according to claim 1 further comprising bearing blocks (40, 41) attached to said block-like structure (16) to provide bearings for the tape guide means (14, 15); and bearing sleeves (42, 43) comprising cast, or molded material in said bearing blocks.
Claim 4
Dependent Claim
17 words
Structure according to claim 1 wherein the cast, or molded material comprises a hardened, or cured resin.
Claim 5
Dependent Claim
15 words
Structure according to claim 3 wherein the hardened, or cured resin is an epoxy resin.
Claim 6
Dependent Claim
20 words
Structure according to claim 4 wherein the epoxy resin is curable, upon addition of a curing agent, at room temperature.
Claim 7
Dependent Claim
12 words
Structure according to claim 3 wherein the resin includes a filler material.
Claim 8
Dependent Claim
12 words
Structure according to claim 6 wherein the filler material includes milled quartz.
Claim 9
Dependent Claim
23 words
Structure according to claim 7 wherein the proportion of milled quartz to resin is, by weight, approximately 26% resin and 74% milled quartz.
Claim 10
Dependent Claim
15 words
Structure according to claim 1 wherein said block-like structure is made of a lightweight metal.
Claim 11
Dependent Claim
30 words
Structure according to claim 1 wherein said bearing seats are formed as button-like projections extending at discrete positions slightly outside of said surface on the block-like structure facing the drum.
Claim 12
Dependent Claim
47 words
Structure according to claim 1, wherein said block-like structure (16) is made of light-weight metal and the cast or molded material comprises a hardened, or cured resin which is dimensionally stable upon setting or curing and is essentially immune with respect to shrinking or expansion upon curing.
Claim 13
Dependent Claim
12 words
Structure according to claim 11, wherein the resin includes a filler material.
Claim 14
Dependent Claim
182 words
Method of making a scanning head structure for wide band magnetic recording/reproducing tape (11), particularly for video tape recording, having an essentially cylindrical drum (10) and a block-like support structure (16) on which the drum is to be secured in accurately positioned relation, the structure having a surface facing the essentially cylindrical drum and approximately matching the cylindrical surface of the drum, comprising the steps of forming a plurality of openings (17'-24') extending through said block-like structure and terminating at said surface; fitting a fill foil against said surface, while leaving said openings uncovered; providing a mandrel (1) having a cylindrical structure similar to the drum (10); coating the mandrel (1) with a separating medium; introducing a flowable hardenable casting, or molding compound through said openings from a region of said block-like structure remote from said surface until said casting, or molding compound contacts the mandrel; and permitting said casting or molding compound to harden to form a seating, or bearing area (17, 18, 19, 20; 21, 22, 23, 24) for the drum which is unvarying with respect to the support structure.
Claim 15
Dependent Claim
182 words
Method of making a scanning head structure for wide band magnetic recording/reproducing tape (11), particularly for video tape recording, having an essentially cylindrical drum (10) and a block-like support structure (16) on which the drum is to be secured in accurately positioned relation, the structure having a surface facing the essentially cylindrical drum and approximately matching the cylindrical surface of the drum, comprising the steps of forming a plurality of openings (17'-24') extending through said block-like structure and terminating at said surface; fitting a fill foil against said surface, while leaving said openings uncovered; providing a mandrel (1) having a cylindrical structure similar to the drum (10); coating the mandrel (1) with a separating medium; introducing a flowable hardenable casting, or molding compound through said openings from a region of said block-like structure remote from said surface until said casting, or molding compound contacts the mandrel; and permitting said casting or molding compound to harden to form a seating, or bearing area (17, 18, 19, 20; 21, 22, 23, 24) for the drum which is unvarying with respect to the support structure.
Claim 16
Dependent Claim
22 words
Method according to claim 13 wherein the step of introducing said casting or molding compound is carried out under essentially pressure-less conditions.
Claim 17
Dependent Claim
42 words
Method according to claim 13 wherein the block further includes bearing means (40, 41) for tape guide rollers; and further including the step of introducing the bearing sleeve liner compound into said bearing blocks to form a bearing sleeve liner (42, 43).
Claim 18
Dependent Claim
34 words
Method according to claim 13 wherein said block-like structure (16) includes locating bores (17, 25) and guide slits (26); further including the step of introducing core, material into said locating bores and guide slits.
Claim 19
Dependent Claim
17 words
Method according to claim 13 wherein said casting or molding material comprises a hardenable, or curable resin.
Claim 20
Dependent Claim
22 words
Method according to claim 17 wherein said resin comprises an epoxy resin and a curing or setting agent, curing at room temperature.
Claim 21
Dependent Claim
27 words
Method according to claim 17 wherein said resin is dimensionally stable upon setting or curing and is essentially immune with respect to shrinking or expansion upon curing.
Claim 22
Dependent Claim
13 words
Method according to claim 17 further including a filler material in said resin.
Claim 23
Dependent Claim
12 words
Method according to claim 20 wherein said filler material comprises milled quartz.
Claim 24
Dependent Claim
23 words
Method according to claim 21 wherein the proportion of filler material to resin, by weight, is approximately 26% resin and 74% filler material.
Claim 25
Dependent Claim
47 words
Method according to claim 13, wherein said block-like structure (16) is made of light-weight metal and the cast or molded material comprises a hardened, or cured resin which is dimensionally stable upon setting or curing and is essentially immune with respect to shrinking or expansion upon curing.
Claim 26
Dependent Claim
13 words
Method according to claim 23, further including a filler material in said resin.
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) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |