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Retractile Cord Design
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Coil Cords are formed by spirally wrapping cable around a metal or plastic mandrel, heating to a "set" temperature, and then "reversing" the coils to give the cord the necessary retractile memory.
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"Cord Styles"
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"Cable Styles"
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Retractile Cord Design Equations |
| C |
Overall Coil O.D. |
| M |
Mandrel Size (Common Sizes .125", .1875", .250", .3125", .375", .4375", .500", .5625", .750", 1.00") |
| B |
Body Length |
| p |
3.14159 |
| D |
Major Dimension of Cable to be Coiled |
| d |
Minor Dimension of Cable to be Coiled |
| TA |
Tangent A |
| TB |
Tangent B |
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Calculations for Coil Cords: Number of Coils in Coil Cord C (Overall Coil Diameter) (Estimate Only) Length of Cable Used in Coil Cord
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Round Cable B/D 1.2M + 2D pB(C-D)+ TA + TB D
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Flat Cable B/D 1.2M + 2d pB(C-d)+ TA + TB D
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COIL CORD GUIDELINES: |
| I. |
Body Length |
Minimum Tolerances |
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a. Less than 3" |
+/-1/4" |
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b. 3" to 6" |
+/-1/2" |
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c. 6" to 12" |
+/-1/2" |
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d.12" to 18" |
+/-1" (Will accept +/-1/2") |
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e. Over 18" |
+/-2" (Will accept +/-1") |
| II. |
Body O.D. |
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a. All coils |
+/-10% |
| III. |
Tangents without Modular Plugs |
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a. Nominal tangent dimension "X" measured form end of tangent to closes point of coil body b. Minimum Tolerance +/- 1/2" |
| IV. |
Tangents with Modular Plugs |
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a. Nominal tangent dimension "X" represents length of straight cable between plug and closest point of coil body. b. Minimum Tolerance +/-1" (Will Accept +/-1/2") | |
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