Vibration Isolating Arm
Traffic crossing bridges and overpasses can set up vibrations that can literally shake apart lighting fixtures mounted on these structures. Premature lamp failure is the most common result. Fixtures or brackets can also tear loose and, in some cases, light fixtures can fall off their bracket. Early replacement of these kinds of lighting systems before their expected life-cycle can quickly add up to significant expenditures.
At Hapco, we have responded to this challenge by developing a patented spring suspension and friction damping system that isolates the luminaire from the vertical vibration of the pole. In tests, our damped arm significantly reduces free vibration – from 110 cycles for a standard, non-damping arm to 10 cycles for the damped system.
Other lab and field tests support these results, including findings from a specific installation site that has been monitored from December of 1994. For a report on these findings or any additional information about the Vibration Isolating Arm, please contact Hapco.
U.S. Patent No. 5601274
Free Vibration With Standard Arm
The Vibration Isolating Arm support system’s natural frequency is below the range of frequencies that result in damage to the light fixture.