# US 7,461,440 B2 · Blind, blind slat, manufacturing method of the same, and forming machine of the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,461,440 B2 - Document ID: US7461440B2 - Status: Granted - Kind: B2 - Application number: 11/136,486 - Filed: 2005-05-25 - Published: 2005-12-08 - Granted: 2008-12-09 - Earliest claimed: 2003-09-22 - Assignees: Kabushiki Kaisha Nichibei - Inventors: Sumitaka Sasaki; Toshikazu Okita; Eiji Sakuma - Web page: https://patentgrep.com/patent/US7461440B2 ## CPC - 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)} - E06B 9/386: Details of lamellae - Y10T 29/39: Venetian blind assembling - Y10T 29/51: Plural diverse manufacturing apparatus including means for metal shaping or assembling - Y10T 29/53696: Means to string - E06B: FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES (shades or blinds for greenhouses A01G9/22; curtains A47H; lids for car boots or bonnets B62D25/10; skylights E04B7/18; sunshades, awnings E04F10/00) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## 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 ### Claim 1 A forming machine of a slat, said machine comprising: a die formed with a recess in a position corresponding to a lift cord passing hole, and formed with a projection on a position corresponding to a protrusion to be formed on said slat; 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, wherein 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. ### Claim 2 (depends on 1) The forming machine according to claim 1, 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. ### Claim 3 (depends on 2) The forming machine of claim 2, wherein said first and second dies are integrally formed and provided separately to allow replacement of said second die. ### Claim 4 (depends on 1) The forming machine of claim 1, wherein said projection is pressed by said cushioning portion to form said protrusion such that said protrusion 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. ### Claim 5 (depends on 1) The forming machine of claim 1, wherein 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. ### Claim 6 (depends on 1) The forming machine of claim 1, wherein 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. ### Claim 7 (depends on 1) The forming machine of claim 1, wherein a maximum height of the protrusion of said slat is in a range from 0.1 mm to 0.6 mm. ### Claim 8 (depends on 1) The forming machine of claim 1, wherein a root of said protrusion gently rises from the general plane to form a curve. ### Claim 9 (depends on 1) The forming machine of claim 1, wherein a projecting surface of the protrusion of said slat has a radius of curvature in a range from 0.3 mm to 4 mm. ### Claim 10 (depends on 1) The forming machine of claim 1, wherein the protrusion of said slat linearly extends in parallel with the longitudinal direction of the slat. ### Claim 11 (depends on 1) The forming machine of claim 1, wherein the protrusion of said slat extends to form an arc surrounding the edge of the lift cord passing hole. ### Claim 12 (depends on 1) The machine of claim 1, wherein said recess is one of a through hole and a hole with a bottom surface. ### Claim 13 (depends on 1) The forming machine of claim 1, wherein said cushioning portion comprises urethane rubber. ### Claim 14 (depends on 1) The forming machine of claim 1, wherein said cushioning portion protrudes beyond a cutting edge of the punch in a natural state. ### Claim 15 (depends on 1) The forming machine of claim 1, wherein said cushioning portion comprises cushioning holders connected with springs. ### Claim 16 A machine for forming a blind slat, comprising: means for forming a slat 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 means for forming said slat 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. ### Claim 17 (depends on 16) The forming machine of claim 16, wherein 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. ### Claim 18 (depends on 16) The forming machine of claim 16, wherein 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. ### Claim 19 (depends on 16) The forming machine of claim 16, wherein a maximum height of the protrusion of said slat is in a range from 0.1 mm to 0.6 mm. ### Claim 20 (depends on 16) The forming machine of claim 16, wherein a root of said protrusion gently rises from the general plane to form a curve. ### Claim 21 (depends on 16) The forming machine of claim 16, wherein a projecting surface of the protrusion of said slat has a radius of curvature in a range from 0.3 mm to 4 mm. ### Claim 22 (depends on 16) The forming machine of claim 16, wherein the protrusion of said slat linearly extends in parallel with the longitudinal direction of the slat. ### Claim 23 (depends on 16) The machine of claim 16, wherein the protrusion of said slat extends to form an arc surrounding the edge of the lift cord passing hole.