Patent US3917068A successfully refreshed from Google Patents.
US3917068A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disc cartridge including draw plate
Assignee: Nashua Corp
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Filing: 1974-07-19
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Granted: 1975-11-04
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Expires: 1994-07-19
Abstract
Abstract The tendency of circular draw plates used in disc cartridges containing a magnetic disc memory to warp during fabrication is significantly reduced by a draw plate which includes two warp reducing apertures each spaced at an angle of 90* from the posts along the circumference of said draw plate. An improved post is disclosed. The post includes a coarse knurl which is urged into a post aperture formed in the draw plate. A ring magnet in the bottom cover is also disclosed. The single ring magnet replaces several pot magnets of prior art cartridges and significantly reduces the cost of producing the disc cartridge.
Inventors
- 👤 George T Cheney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:35
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/32; G11B23/00; G11B23/02; G11B23/03; G11B23/032; G11B23/0321; G11B23/0322
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
112 words
A circular draw plate for a disc cartridge of the type which has post apertures through which posts are secured to the draw plate and a pair of posts for engagement with a handle assembly on a cover of the disc cartridge wherein the improvement comprises a circular draw plate having a pair of warp reducing apertures, each of said warp reducing apertures and the post apertures being located an equal distance from the center of the circular draw plate and each warp reducing aperture being along an inner circumference of said circular draw plate at a distance of 90* of arc from a post aperture also located along said inner circumference.
Claim 2
Dependent Claim
112 words
A circular draw plate for a disc cartridge of the type which has post apertures through which posts are secured to the draw plate and a pair of posts for engagement with a handle assembly on a cover of the disc cartridge wherein the improvement comprises a circular draw plate having a pair of warp reducing apertures, each of said warp reducing apertures and the post apertures being located an equal distance from the center of the circular draw plate and each warp reducing aperture being along an inner circumference of said circular draw plate at a distance of 90* of arc from a post aperture also located along said inner circumference.
Claim 3
Dependent Claim
27 words
The draw plate as set forth in claim 1 wherein said draw plate includes a central aperture centered between said warp reducing apertures and said post apertures.
Claim 4
Dependent Claim
20 words
The draw plate as set forth in claim 2 wherein said draw plate has an outer circular rim formed thereon.
Claim 5
Dependent Claim
20 words
The draw plate as set forth in claim 3 wherein said central aperture is defined by an inner circular rim.
Claim 6
Dependent Claim
33 words
The draw plate as set forth in claim 4 wherein said outer circular rim and said inner circular rim both extend above and below the plane of the body of the draw plate.
Claim 7
Dependent Claim
44 words
The draw plate as set forth in claim 5 wherein said post apertures are defined by circular rims and wherein said warp reducing apertures are also defined by circular rims which have a circumference approximately equal to the circular rims defining the post apertures.
Claim 8
Dependent Claim
31 words
The draw plate as set forth in claim 6 wherein said rims defining said warp reducing aperture and said rims defining said post apertures contact said rim defining said central aperture.
Claim 9
Dependent Claim
67 words
The draw plate as set forth in claim 1 wherein the bottom of the posts have a coarse knurl formed thereon which friction fits directly into a post aperture formed in the material from which the draw plate is fabricated, the direct fitting of said posts into the draw plate enabling the posts to be flexed to facilitate the alignment of the posts with the handle assembly.
Claim 10
Dependent Claim
67 words
The draw plate as set forth in claim 3 wherein the bottom of the posts have a coarse knurl formed thereon which friction fits directly into a post aperture formed in the material from which the draw plate is fabricated, the direct fitting of said posts into the draw plate enabling the posts to be flexed to facilitate the alignment of the posts with the handle assembly.
Claim 11
Dependent Claim
67 words
The draw plate as set forth in claim 7 wherein the bottom of the posts have a coarse knurl formed thereon which friction fits directly into a post aperture formed in the material from which the draw plate is fabricated, the direct fitting of said posts into the draw plate enabling the posts to be flexed to facilitate the aligNment of the posts with the handle assembly.
Claim 12
Dependent Claim
138 words
A disc cartridge of the type which includes a memory disc covered by two covers, a top and a bottom cover, and a draw plate of a type which has post apertures through which posts are secured to the draw plate and a pair of posts for engagement with a handle assembly on one cover and which draws the memory disc toward one cover when the handle is rotated wherein the improvement comprises said draw plate having a pair of warp reducing apertures, each of said warp reducing apertures and the post apertures being located an equal distance from the center of the circular draw plate and each warp reducing aperture being along an inner circumference of said circular draw plate at a distance of 90* of arc from a post aperture also located along said inner circumference.
Claim 13
Dependent Claim
138 words
A disc cartridge of the type which includes a memory disc covered by two covers, a top and a bottom cover, and a draw plate of a type which has post apertures through which posts are secured to the draw plate and a pair of posts for engagement with a handle assembly on one cover and which draws the memory disc toward one cover when the handle is rotated wherein the improvement comprises said draw plate having a pair of warp reducing apertures, each of said warp reducing apertures and the post apertures being located an equal distance from the center of the circular draw plate and each warp reducing aperture being along an inner circumference of said circular draw plate at a distance of 90* of arc from a post aperture also located along said inner circumference.
Claim 14
Dependent Claim
27 words
The draw plate as set forth in claim 11 wherein said draw plate includes a central aperture centered between said warp reducing apertures and said post apertures.
Claim 15
Dependent Claim
20 words
The draw plate as set forth in claim 12 wherein said draw plate has an outer circular rim formed thereon.
Claim 16
Dependent Claim
20 words
The draw plate as set forth in claim 13 wherein said central aperture is defined by an inner circular rim.
Claim 17
Dependent Claim
33 words
The draw plate as set forth in claim 14 wherein said outer circular rim and said inner circular rim both extend above and below the plane of the body of the draw plate.
Claim 18
Dependent Claim
43 words
The draw plate as set forth in claim 15 wherein the post apertures are defined by circular rims and wherein said warp reducing apertures are also defined by circular rims which have a circumference approximately equal to the rims defining said post apertures.
Claim 19
Dependent Claim
31 words
The draw plate as set forth in claim 16 wherein said rims defining said warp reducing aperture and said rims defining said post apertures contact said rim defining said central aperture.
Claim 20
Dependent Claim
109 words
The disc cartridge as set forth in claim 11 wherein the bottom of the posts have a coarse knurl formed thereon which friction fits directly into a post aperture formed in the material from which the draw plate is fabricated, the direct fitting of said posts into the draw plate enabling the posts to be flexed to facilitate the alignment of the posts with the handle assembly and wherein the bottom cover of the cartridge includes a ring magnet positioned on the inside thereof, said ring magnet making magnetic contact with an armature plate which is connected to said top cover to maintain said cartridge in a closed position.
Claim 21
Dependent Claim
109 words
The disc cartridge as set forth in claim 13 wherein the bottom of the posts have a coarse knurl formed thereon which friction fits directly into a post aperture formed in the material from which the draw plate is fabricated, the direct fitting of said posts into the draw plate enabling the posts to be flexed to facilitate the alignment of the posts with the handle assembly and wherein the bottom cover of the cartridge includes a ring magnet positioned on the inside thereof, said ring magnet making magnetic contact with an armature plate which is connected to said top cover to maintain said cartridge in a closed position.
Claim 22
Dependent Claim
109 words
The disc cartridge as set forth in claim 17 wherein the bottom of the posts have a coarse knurl formed thereon which friction fits directly into a post aperture formed in the material from which the draw plate is fabricated, the direct fitting of said posts into the draw plate enabling the posts to be flexed to facilitate the alignment of the posts with the handle assembly and wherein the bottom cover of the cartridge includes a ring magnet positioned on the inside thereof, said ring magnet making magnetic contact with an armature plate which is connected to said top cover to maintain said cartridge in a closed position.
References Cited (Backward Citations)
US1761932A
Cited
US2155667A
Cited
US2424106A
Cited
US3391817A
Cited
US3635608A
Cited
US3753490A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |