The thing about drum patterns, when it comes to sampling or reproducing or what have you, is that drums are fairly standard across the board when it comes to what you can do with them. For instance, you can create unique fills, but you'd get laughed out of any court if you tried to say you originated the four on the floor house rhythm of such and such track and that no one else can use it.
Guitars and any sort of melodic instrument, on the other hand, allow you to score completely original melodies and complex harmonies and so on, with unique tunings and various other amenities that are fully comprehensible as "off limits" legally speaking for non-paying samplistsor musicians who'd want to reproduce the riff.
However, these drum fills and long melodic phrases are only fully distinguishable as unique when heard in the context of the original work. When a single drum hit or short fill is sampled, or when you happen to use a 3-chord progression that was used in some particular song, you have nothing to fear.
I'm no lawyer, but I say don't worry about your drum pattern. Like Tutor said, IN THEORY you'd need permission to use it, but fuhgettaboutit.
-tank.
You don't know what I know
Cuz you aint seen through my eyes
This spliff is always lit but it's a natural high
http://www.dcbeats.net