Elevator rope
An elevator rope comprising an elastomer coated, multistrand steel wire cable is claimed. In such a cable strands have a lay-length of at least 6.5 times the diameter of the bare cable diameter D. The cable is further coated with an elastomeric jacket, which adheres to the strands with a pull-out force not less than 15×D+15 newton per mm. The advantages of such an elevator rope are amongst others its limited elongation, its reduced diameter and its improved fatigue life.
1. An elevator rope having a bare rope diameter D, said elevator rope comprising a core strand and at least five outer strands twisted around said core strand, said core strand and said outer strands comprising a plurality of steel wires, said elevator rope further comprising a jacket, said jacket comprising an elastomer, said jacket surrounding and penetrating between said outer strands characterised in that
said jacket adheres to at least said outer strands with a pull-out force expressed in N/mm not less than 15×D+15 where D is expressed in mm and in that;
the lay length of said outer strands around said core strand is larger than 6.5 times D.
2. An elevator rope as in claim 1 , wherein said jacket adheres to at least said outer strands with a pull-out force of not less than 15×D+30.
3. An elevator rope as in claim 1 , wherein the lay length of said outer strands around said core strand is smaller than 12 times D.
4. An elevator rope as in claim 1 , wherein the lay length of said outer strands around said core strand is between 7 and 10 times D.
5. An elevator rope as in claim 1 , wherein said outer strands comprises filaments with a tensile strength of at least 2650 N/mm 2 .
6. An elevator rope as in claim 5 , wherein said core strand comprises filaments with a tensile strength of at most 2650 N/mm 2 .
7. An elevator rope as in claim 5 , wherein said core strand comprises filaments with a tensile strength of at most 2500 N/mm 2 .
8. An elevator rope as in claim 1 , wherein said rope has an elastomer filling degree of at least 15% between said outer strands.
9. An elevator rope as in claim 1 , wherein said rope has an elastomer filling degree of at least 30% between said outer strands.
10. An elevator rope as in claim 1 , wherein said elastomer is a thermoplastic elastomer.
11. An elevator rope as in claim 1 , wherein said elastomer is a polyurethane.
12. An elevator rope as in claim 1 , wherein said elastomer is a rubber.
13. A method to produce an elevator rope having a bare rope diameter D and the product resulting from said method, said method characterized by the following steps:
A. Assembling the outer strands around the core strand with a lay length that is larger than 6.5 times D.
B. Coating the rope with a primer in order to obtain a pull-out force expressed in N/mm of at least 15×D+15 where D is expressed in mm.
C. Applying the outer jacket around the rope.
14. A method according to claim 13 wherein said outer strands have a preforming ratio between 95 and 100%.
15. A method according to claim 13 wherein the preforming ratio is between 96 and 98%.
16. A method according to claim 13 , wherein the primer is an organo functional silane.
17. A method according to claim 13 , wherein the primer is an organo functional titanate.
18. A method according to claim 13 , wherein the primer is an organo functional zirconate.
19. A method according to claim 13 , wherein the elastomer is applied by means of an extrusion.