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US3789904A Expired / Lapsed US ⏱️ 0.0 years remaining

Double curtain device

Assignee: Individual
•
Filing: 1973-01-15
•
Granted: 1974-02-05
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Expires: 1993-01-15
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Abstract

Abstract A double curtain device wherein a curtain (5) provided with punched patterns (29) is connected at the respective ends with a main winding shaft (2) and auxiliary winding shaft (3) both rotatably provided between right and left supporting cases (1), a balance weight shaft (8) is inserted and held in a folded part (7) of the curatin (5) so as to tension the curtain (5), a joint (9) is slidably fitted to the main winding shaft (2) so that the length of the main winding shaft (2) may be adjustable, said auxiliary winding shaft (3) is formed by fitting a small diameter tube (15) provided with an axial groove (14) cut on one side into a large diameter tube (16) provided also with an axial groove (14) cut on one side, many annular concave grooves (17) and annular convex parts (18) fitting them are formed respectively in the fitting parts of the small diameter tube (15) and large diameter tube (16) so that the length of the auxiliary winding shaft may be adjustable and a winding chain (25) is hung on a chain wheel (24) secured to one end of the auxiliary winding shaft (3) and engaging holes (26) for said winding chain (25) are made as opposed to the chain (25) on the lower surface of the supporting case (1).

Inventors

  • 👤 I Takazawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 18:36
CPC Classifications
A; A47; A47H; A47H23/00; A47H23/02; A47H23/04; A47H23/06; A47H1/00

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 193 words
A double curtain device wherein a curtain provided with punched patterns is connected at the respective ends with a main winding shaft and auxiliary winding shaft both rotatably provided between right and left supporting cases, a balance weight shaft is inserted and held in a folded part of the curtain so as to tension the curtain, a joint is slidably fitted to the main winding shaft (2) so that the length of the main winding shaft may be adjustable, said auxiliary winding shaft is formed by fitting a small diameter tube provided with an axial groove cut on one side into a large diameter tube provided also with an axial groove cut on one side, many annular concave grooves and annular convex parts fitting them are formed respectively in the fitting parts of the small diameter tube and large diameter tube so that the length of the auxiliary winding shaft may be adjustable, a winding chain is hung on a chain wheel secured to one end of the auxiliary winding shaft and engaging holes for said winding chain are made as opposed to the chain on the lower surface of the supporting case.
Claim 2
Dependent Claim 193 words
A double curtain device wherein a curtain provided with punched patterns is connected at the respective ends with a main winding shaft and auxiliary winding shaft both rotatably provided between right and left supporting cases, a balance weight shaft is inserted and held in a folded part of the curtain so as to tension the curtain, a joint is slidably fitted to the main winding shaft (2) so that the length of the main winding shaft may be adjustable, said auxiliary winding shaft is formed by fitting a small diameter tube provided with an axial groove cut on one side into a large diameter tube provided also with an axial groove cut on one side, many annular concave grooves and annular convex parts fitting them are formed respectively in the fitting parts of the small diameter tube and large diameter tube so that the length of the auxiliary winding shaft may be adjustable, a winding chain is hung on a chain wheel secured to one end of the auxiliary winding shaft and engaging holes for said winding chain are made as opposed to the chain on the lower surface of the supporting case.

References Cited (Backward Citations)

US1299481A Cited
US2307095A Cited
US2281022A Cited
US2581433A Cited
US3128688A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-02-04 1977-08-06 1978-02-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-02-04 1981-08-06 1982-02-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-02-04 1985-08-06 1986-02-05 $7700.00 Window Closed / Lapsed

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