Patent US4373224A successfully refreshed from Google Patents.
US4373224A
Expired / Lapsed
US
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Method for manufacturing a duster and the duster manufactured therefrom
Assignee: Duskin Franchise Co Ltd
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Filing: 1981-04-21
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Granted: 1983-02-15
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Expires: 2001-04-21
Abstract
Abstract A method for manufacturing a duster and the duster manufactured therefrom are described, the duster head being made of strands of a blend polymer film of a mixture of isotactic polypropylene and polyethylene, which has been processed to be in an electret state, so that dust collecting and holding efficiency are improved and gross bulk, and texture of the head of the duster are highly improved with rich resiliency and a convenient usage being provided.
Inventors
- 👤 Shinji Bandai
- 👤 Masao Kajimaki
- 👤 Yoshihiro Nakajima
- 👤 Akira Yagi
- 👤 Haruo Nishimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:28
CPC Classifications
A; A47; A47L; A47L13/00; A47L13/10; A47L13/40; A47L13/38; Y; Y10; Y10S; Y10S15/00; Y10S15/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A method for manufacturing a duster, comprising the steps of: (a) providing a film consisting of a blend of isotactic polypropylene and polyethylene polymers, said blend being of a weight ratio in the range 95:5 to 70:30, and substantially elongating the film; (b) treating the elongated film by a corona charge sufficiently to create an electret state in said elongated film; (c) splitting the elongated film into a plurality of rows of ribbon-like fibers; (d) crimping the fibers without substantially eliminating the electret state; and (e) attaching said plurality of rows of crimped ribbon-like fibers to a duster stem.
Claim 2
Independent Claim
99 words
A method for manufacturing a duster, comprising the steps of: (a) providing a film consisting of a blend of isotactic polypropylene and polyethylene polymers, said blend being of a weight ratio in the range 95:5 to 70:30, and substantially elongating the film; (b) treating the elongated film by a corona charge sufficiently to create an electret state in said elongated film; (c) splitting the elongated film into a plurality of rows of ribbon-like fibers; (d) crimping the fibers without substantially eliminating the electret state; and (e) attaching said plurality of rows of crimped ribbon-like fibers to a duster stem.
Claim 3
Dependent Claim
27 words
The method of claim 1, wherein: in conducting step (a) the film is elongated by an amount in the range of 6.0-8.5 times the original length thereof.
Claim 4
Dependent Claim
22 words
The method of claim 1, wherein: in conducting step (b), the corona charge is applied via a plurality of corona charging wires.
Claim 5
Dependent Claim
78 words
The method of claim 1; wherein: in conducting step (e), the crimped ribbon-like fibers are each assembled midway along their length to a respective holder, a plurality of such fibers to each holder to create a respective frond-like row of such fibers; the duster stem being provided with at least one groove along the length thereof, and the holder being inserted in the groove and fastened to the duster stem to mount the fibers to the duster stem.
Claim 6
Dependent Claim
50 words
The method of claim 4, wherein: the at least one groove is spirally provided on the duster stem and said holder of said respective row of fibers is wound into said spirally provided groove, so that said fibers project from the duster stem about the circumference of the duster stem.
Claim 7
Dependent Claim
74 words
The method of claim 5, wherein: the at least one groove extends from one end of the duster stem to a site intermediate that end and an opposite end of the duster stem and the holder is fastened to the duster stem by fastening one end of the holder to said one end of said duster stem and by fastening an opposite end of the holder to said intermediate site on said duster stem.
Claim 8
Dependent Claim
10 words
A duster manufactured according to the method of claim 6.
References Cited (Backward Citations)
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US3018263A
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US3644605A
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US3691264A
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US4305173A
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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) | 1986-02-14 | 1986-08-16 | 1987-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-14 | 1990-08-16 | 1991-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-14 | 1994-08-16 | 1995-02-15 | $7700.00 | Window Closed / Lapsed |