A support frame mounts to a surface and for receives a support tube having
a locking button. The support frame includes a cap for affixing the
support frame to the surface. A sleeve is attached to the cap for
receiving the support tube and for engaging the locking button. A filler
sleeve is disposed in the sleeve for abutting an end of the support tube.
A spring is disposed in the sleeve for biasing the filler sleeve against
the support tube. The filler sleeve has a stop for limiting the travel of
the filler sleeve and for retaining the filler sleeve in the sleeve.