Bend limiter

• US 20080175555A1
• Filed: 04/18/2007
• Published: 07/24/2008
• Est. Priority Date: 04/20/2006
• Status: Active Grant

• Current Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom))
• Inventors: Gurreri, Michael Lawrence
• Granted Patent: US 7,695,197 B2
• Time in Patent Office: Days
• US Class Current: 385/137
• CPC Class Codes: G02B 6/38875 Protection from bending or twisting

Abstract

A bend limiter for use with electrical and fiber optic cables that can handle a relatively wide range of side loading without excessive bending is disclosed. The bend limiter is configured to bend at radii which are less than the critical curvature of the cable over a range of loads. The bend limiter includes a flexible member having two portions. One portion has a non-linear profile and is designed to absorb high loads to control bending. The other portion has a tapered linear profile and is designed to bend under light loads so that a conductor at the tip of the bend limiter does not kink.

Claims

1. A bend limiter for a conductor having a minimum bend radius comprising

a flexible member having a center bore to accommodate said conductor, a first end suitable for mounting to an end of a connector, and an opposite second end, said flexible member tapering from a relatively large first diameter at said first end to a relatively small second diameter at said second end such that said flexible member bends at essentially a radius which is no less than said minimum bend radius when a variable load having a range ratio of no less than 1:

1.5 is applied to said conductor extending from said second end.

2. The bend limiter of claim 1, wherein said taper comprises a non-linear portion from said first end to an intermediate point and a linear portion from said intermediate point to said second end.

3. The bend limiter of claim 2, wherein said non-linear portion has an outside diameter D_o +/−

5% at a distance s from the first end consistent with the following formula;

$D_o=\sqrt[4]{\frac{64<br><br><br><br>{\mathrm{PR}}^2}{\mathrm{\pi <br><br>}<br><br><br><br>E}<br><br>\left(1-\sin <br><br>\left(\frac{s}{R}\right)\right)+D_i^4}$

4. The bend limiter of claim 2, wherein said non-linear portion has an outside diameter is f₁(l)+/−

5% consistent with the following formula;

$f_1<br><br>\left(l\right)=\frac{1}{2}·<br><br>k+\sqrt{r^2-{\left(l-h\right)}^2}$

wherein r is the radius of curvature, h is the axial position of the radius center, and k is a transverse coordinate of the radius center.

5. The bend limiter of claim 3, wherein said non-linear portion is continuous such that each said D_o along the length of the flexible member complies with said formula.

6. The bend limiter of claim 3, wherein said non-linear portion is stepped such that periodic D_o along the length of the flexible member comply with said formula.

7. The bend limiter of claim 3, wherein said linear portion extends from D_oi at intermediate point s_i to said second diameter.

8. The bend limiter of claim 3, wherein said linear portion tapers from D_oi to said second diameter.

9. The bend limiter of claim 3, wherein said linear portion is essentially constant from D_oi to said second diameter.

10. The bend limiter of claim 1, wherein the length ratio of said non-linear portion to said linear portion is about 1.5:

1 to about 4;

1.

11. The bend limiter of claim 1, wherein said ratio is no less than about 1:

2

12. The bend limiter of claim 1, wherein said ratio is no less than about 1:

2.5

13. The bend limiter of claim 1, wherein said range is about ¼

to about 7/10 kg.

14. The bend limiter of claim 1, wherein said constant radius is no less than about 12 mm.

15. The bend limiter of claim 1, wherein an axial cross section of said flexible member is circular.

16. The bend limiter of claim 1, wherein cross section is a polygonal.

17. The bend limiter of claim 1, further comprising:

a connector interface connected to said first end, said connector interface adapted to be disposed over a rear portion of a connector.