Window regulator cable tensioner
View Patent ↗A window regulator cable tensioner includes a screw and nut assembly having an irreversible thread lead angle, a first spring to absorb reversible slack in the cable, and a second spring to actuate movement of the screw and nut assembly. The stiffness of the first spring is greater than the stiffness of the second spring. The cable tensioner absorbs the reversible slack in the cable differently from irreversible slack in the cable.
1. A window regulator cable tensioner comprising:
a threaded assembly including an irreversible thread lead angle, wherein the threaded assembly comprises a nut and a screw;
a first resilient member having a first stiffness to absorb reversible slack in a cable; and
a second resilient member having a second stiffness to actuate movement of the screw relative to the nut, wherein the first stiffness of the first resilient member is greater than the second stiffness of the second resilient member, and the second resilient member actuates the movement of the screw relative to the nut when the first resilient member is fully expanded.
2. The window regulator cable tensioner according to claim 1 , wherein the first resilient member provides a first restoring force between 60 N and 80N.
3. The window regulator cable tensioner according to claim 1 , wherein the second resilient member provides a second restoring force between 25 N and 40 N.
4. The window regulator cable tensioner according to claim 1 , wherein the first resilient member expands to a length between 2 and 8 mm to absorb the reversible slack in the cable.
5. The window regulator cable tensioner according to claim 1 , wherein the first resilient member is arranged in series with the threaded assembly.
6. The window regulator cable tensioner according to claim 5 , further including a cable sheath centered on the cable, wherein the first resilient member is compressed against the screw by the cable sheath.
7. The window regulator cable tensioner according to claim 1 , wherein the second resilient member is arranged in parallel with the threaded assembly.
8. The window regulator cable tensioner according to claim 7 , wherein the nut forms a fixed stop and the screw forms a movable stop, and the second resilient member is located between the fixed stop and the moveable stop.
9. The window regulator cable tensioner according to claim 1 , wherein the second resilient member contacts an end of the nut and a portion of the screw.
10. The window regulator cable tensioner according to claim 1 , wherein the second resilient member is located outside the screw and the first resilient member is located in a cavity inside the screw.
11. The window regulator cable tensioner according to claim 1 , wherein the second resilient member surrounds the first resilient member.
12. The window regulator cable tensioner according to claim 1 , wherein the first resilient member and the second resilient member are co-axial.
13. A window regulator comprising:
a cable to actuate movement of a window; and
a cable tensioner including a threaded assembly having an irreversible thread lead angle, the threaded assembly including a screw and a nut, the cable tensioner including a first resilient member having a first stiffness to absorb reversible slack in the cable, and a second resilient member having a second stiffness to actuate movement of the screw relative to the nut, the first stiffness of the first resilient member being greater than the second stiffness of the second resilient member, wherein the first resilient member absorbs the reversible slack in the cable when the window is at an upper limit and the second resilient member actuates the threaded assembly to absorb irreversible slack in the cable due to wear.
14. The window regulator according to claim 13 , wherein the second resilient member actuates movement of the screw relative to the nut when the first resilient member is fully expanded.
15. The window regulator according to claim 13 , wherein the first resilient member provides a first restoring force between 60 N and 80 N.
16. The window regulator according to claim 13 , wherein the second resilient member is located outside the screw and the first resilient member is located in a cavity inside the screw.
17. The window regulator according to claim 13 , wherein the second resilient member provides a second restoring force between 25 N and 40 N.
18. The window regulator according to claim 13 , wherein the second resilient member contacts an end of the nut and a portion of the screw.
19. The window regulator according to claim 13 , wherein the first resilient member expands to a length between 2 and 8 mm to absorb the reversible slack in the cable.
20. The window regulator according to claim 13 , wherein the first resilient member is arranged in series with the threaded assembly.
21. The window regulator according to claim 20 , further including a cable sheath centered on the cable, wherein the first resilient member is compressed against the screw by the cable sheath.
22. The window regulator according to claim 13 , wherein the second resilient member is arranged in parallel with the threaded assembly.
23. The window regulator according to claim 22 , wherein the nut forms a fixed stop and the screw forms a movable stop, and the second resilient member is located between the fixed stop and the moveable stop.
24. The window regulator according to claim 13 , wherein the second resilient member surrounds the first resilient member.
25. The window regulator according to claim 13 , wherein the first resilient member and the second resilient member are co-axial.