auto sizing of uvs?

is there a way to have a uv automatically fit into the uv space when i unwrap the model? heres an example:

heres my model, its a captains wheel:

and heres its uv after i unwrap it:

as you can see, some of the uvs are very small and could be resized to be much larger. is there a way to have the uv auto sized to fit the space, while still being proportionate to each other?