Pendant Lighting Clamp

Constraint of Torsional Failure Mode for Pendants


A common problem in the lighting industry with pendants with multiple parallel stems (hanging support tubes) is the twisting of these stems over time, thus ruining the stunning aesthetics of perfectly parallel polished tubes supporting an elegant pendant fixture. These stems twist because of their decreased capability to withstand buckling into the first mode shape as the stem lengths are increased. Once twisted the stems form a contact point that produces a meta-stable condition.

This clamp design mitigates this problem by coupling the tubes at the maximum deflection point in the twisting mode to significantly increase the amount of force required to drive the tubes into the twisted state. Once in place between the stems twisting can only occur above and below the coupling, which signifantly reduces the risk due to the shorter overall length. Multiple clamps can be used when needed for extraordinarily long stems on fixtures.

The design was quickly prototyped using 3D printing and successfully tested. From there a production version was created and deployed into current orders. The clamp was so successful that it was also deployed as a warranty fix for already installed pendants with the unsightly twisting problem. Since the design was made as a drop-in component no complex or risky disassembly was required to introduce the fix.