Most rehab power chair users are familiar with EZ Lock, the vehicle securement system. A large bolt
head is mounted underneath the power chair, and the bolt latches in a base on the vehicle floor. Once
clipped in, it locks the power chair in place. Simple enough of a concept, but how does the bolt underneath
the power chair effect everyday performance?|
How It's Attached
EZ Lock, via a local adaptive
driving equipment provider, either welds a nut underneath the power chair, or bolts on a plate or bracket
with the nut (shown above). The bolt then threads into the nut, extending beneath the power chair.
Where The Bolt Is Located
Optimally, the bolt is mounted in line, center with the drive wheel
axles. This is important because when driving over a threshold or such, the bolt rises with the drive
wheels, preventing clearance issues. However, when straddling an object, the bolt can catch, decreasing
ground clearance at the bolt head to 1.5” or thereabouts.
However, 6-wheel power chairs can raise
a unique issue. The front caster arms on most 6-wheel power chairs compress upward on ramp transitions.
As they compress, the center of the power chair usually remains level, driving the bolt head into the
van ramp, scraping as the power chair climbs the ramp. Therefore, it's vital to assess proper bolt height
and position while still at the driving equipment provider to prevent this issue.
Obviously, the lower the EZ Lock bolt protrudes, the greater chance of ground clearance
issues. However, there's often a solution. The given space is between the dock bolted to the van floor,
and the bottom of the power chair. Accordingly, the bolt sticks down to connect with the dock. Often,
there's enough clearance for the dock to be raised, thereby allowing a shorter bolt on the power chair,
increasing ground clearance. Most vehicle equipment providers automatically do a low-mount dock and a
long bolt configuration, so it's important to ask about raising the dock and shortening the bolt to maximize
power chair ground clearance.
Safety and Performance
You'll occasionally hear horror stories
of a consumer's EZ Lock bolt catching on everything. However, with the bolt placed in line with the drive
axles, and configured as short as possible, an EZ Lock system will offer optimal vehicle safety without
hampering power chair performance.
Published 12/2012, Copyright 2012, WheelchairJunkie.com