Updating loaded classes

I’m on my first steps through RoR (following Agile Development with
RoR).

I’ve seen, that unless I add

model :someModelClass

to my controller, that model isn’t get updated (until I restart
WEBRick).

I also include some classes to controller with

require “someControllerClass.rb”

but they aren’t updated until I restart WEBRick. Is there some analog
for “model” method, aimed at updating controllers? Note that these
“controller classes” aren’t inherited from ActionController::Base and
are in fact some helper classes that I consider to be part of
controller.