help - copy new file

I need to copy files to different location but only copy those file havenot been copies yet (new files been created continuously)

does anyone have idea how to do it?

I try use find -newer but it does not work when 2 files created at the same time - only copy one, here is my logic.

if [ ! -a rcp.tim ] ; then
touch rcp.tim
fi
for F in `find . -type f -newer rcp.tim -name 'arch*'|sort`
do
echo "cp $F /newdir/$F"
cp $F /newdir/
cp -p $F rcp.tim
done

thanks