Blind, slat for blinds, and method of producing the same and forming machine therefor

• US 20040089427A1
• Filed: 09/22/2003
• Published: 05/13/2004
• Est. Priority Date: 03/21/2001
• Status: Active Grant

• Current Assignee: Nichibei Co., Ltd.
• Original Assignee: Nichibei Co., Ltd.
• Inventors: Okita, Toshikazu, Sakuma, Eiji, Sasaki, Sumitaka
• Granted Patent: US 7,069,973 B2
• Time in Patent Office: Days
• US Class Current: 160/168.1R
• CPC Class Codes: E06B 9/266 Devices or accessories for making or mounting lamellar blinds or parts thereof cleaning of lamellar blinds A47L4/00; joining plastics plates for making venetian blinds B29C66/437
• CPC Class Codes: E06B 9/386 Details of lamellae
• CPC Class Codes: Y10T 29/39 Venetian blind assembling
• CPC Class Codes: Y10T 29/51 Plural diverse manufacturing apparatus including means for metal shaping or assembling
• CPC Class Codes: Y10T 29/53696 Means to string

Abstract

To provide a blind slat resistant to bending with keeping good rotation of a slat. The slat (16) is formed with a lift cord passing hole (16a) through which a lift cord passes, and when a length of the lift cord passing hole (16a) in a slat width direction is b, a slat width is a, and a slat crown height is e,

0.59·e/a+0.19≦b/a≦−1.41·e/a+0.70

is satisfied, and the slat (16) is formed with a protrusion (16g), which crosses an extension line (16d) of the lift cord passing hole (16a) and protrudes beyond a general plane (16e) of the slat, the extension line (16d) connecting an edge (16b) of the lift cord passing hole (16a) in the slat width direction and an edge (16c) of the slat (16) in the slat width direction.

Claims

1. A blind in which many slats are supported in alignment by a ladder cord suspended from a head box, a top end of the ladder cord is supported by a ladder cord support device provided in the head box, the ladder cord support device is operated to rotate the slats, one end of a lift cord is connected to a bottom rail, which is placed at a bottom of a row of slats and to which a bottom end of the ladder cord is connected, while the other end of the lift cord is passed through the row of slats and introduced into the head box, and said lift cord is raised or lowered to raise or lower the row of slats and the bottom rail,

characterized in that said slat is formed with a lift cord passing hole through which said lift cord passes, and when a length of said lift cord passing hole in a slat width direction is b, a slat width is a, and a slat crown height is e,

0.59·

e/a+0.19≦

b/a≦

−

1.41·

e/a+0.70

is satisfied, and said slat is formed with a protrusion, which crosses an extension line of the lift cord passing hole and protrudes beyond a general plane of the slat, the extension line connecting an edge of the lift cord passing hole in the slat width direction and an edge of the slat in the slat width direction.

2. The blind according to claim 1, characterized in that the protrusion of said slat is positioned such that when a length in the slat width direction from the edge of said lift cord passing hole in the slat width direction to the edge of the slat in the slat width direction is c, and a length in the slat width direction from the edge of said lift cord passing hole in the slat width direction to an intersection between said extension line and the protrusion is d, a range of 0≦

d/c≦

0.8 is satisfied.

3. The blind according to claim 1 or 2, characterized in that when a width of said lift cord passing hole in a longitudinal direction of the slat is f, and a length of the protrusion of said slat in the longitudinal direction of the slat is g, g/f≧

1.6 is satisfied.

4. The blind according to any one of claims 1 to 3, characterized in that a maximum height of the protrusion of said slat is in a range from 0.1 mm to 0.6 mm.

5. The blind according to any one of claims 1 to 4, characterized in that a root of said protrusion gently rises from the general plane to form a curve.

6. The blind according to any one of claims 1 to 5, characterized in that a projecting surface of the protrusion of said slat has a radius of curvature in a range from 0.3 mm to 4 mm.

7. The blind according to any one of claims 1 to 6, characterized in that the protrusion of said slat linearly extends in parallel with the longitudinal direction of the slat.

8. The blind according to any one of claims 1 to 6, characterized in that the protrusion of said slat extends to form an arc surrounding the edge of the lift cord passing hole.

17. A manufacturing method of a blind slat in which a slat according to any one of claims 1 to 16 is formed with a lift cord passing hole,

characterized in that said lift cord passing hole and said protrusion are formed at the same time.

18. A forming machine of a slat for forming a lift cord passing hole in the slat according to any one of claims 1 to 16, comprising:

a die formed with a recess in a position corresponding to the lift cord passing hole, and formed with a projection on a position corresponding to said protrusion;

a punch vertically movable opposite said recess; and

a cushioning portion vertically movable opposite said projection following the punch, and elastically displaceable vertically with respect to the punch.

19. The forming machine according to claim 18, wherein said die includes a first die formed with said recess, and a second die separate from the first die and formed with said projection.

9. A blind slat, characterized in that said slat is formed with a lift cord passing hole through which a lift cord for raising and lowering a blind passes, and when a length of the lift cord passing hole in a slat width direction is b, a slat width is a, and a slat crown height is e,

0.59·

e/a+0.19≦

b/a≦

−

1.41·

e/a+0.70

is satisfied, and said slat is formed with a protrusion, which crosses an extension line of the lift cord passing hole and protrudes beyond a general plane of the slat, the extension line connecting an edge of the lift cord passing hole in the slat width direction and an edge of the slat in the slat width direction.

10. The blind slat according to claim 9, characterized in that the protrusion of said slat is positioned such that when a length in the slat width direction from the edge of said lift cord passing hole in the slat width direction to the edge of the slat in the slat width direction is c, and a length in the slat width direction from the edge of said lift cord passing hole in the slat width direction to an intersection between said extension line and the protrusion is d, a range of 0≦

d/c≦

0.8 is satisfied.

11. The blind slat according to claim 9 or 10, characterized in that when a width of said lift cord passing hole in a longitudinal direction of the slat is f, and a length of the protrusion of said slat in the longitudinal direction of the slat is g, g/f≧

1.6 is satisfied.

12. The blind slat according to any one of claims 9 to 11, characterized in that a maximum height of the protrusion of said slat is in a range from 0.1 mm to 0.6 mm.

13. The blind slat according to any one of claims 9 to 12, characterized in that a root of said protrusion gently rises from the general plane to form a curve.

14. The blind slat according to any one of claims 9 to 13, characterized in that a projecting surface of the protrusion of said slat has a radius of curvature in a range from 0.3 mm to 4 mm.

15. The blind slat according to any one of claims 9 to 14, characterized in that the protrusion of said slat linearly extends in parallel with the longitudinal direction of the slat.

16. The blind slat according to any one of claims 9 to 14, characterized in that the protrusion of said slat extends to form an arc surrounding the edge of the lift cord passing hole.