If you dig in to Philly Joe, you'll hear this signature phrase come up a lot. It's simply three triplets, often played more than once so it rolls over the bar, with an accent on the first note of the first triplet each time.
You could, of course, simply play this as single strokes with no problem. But it is generally accepted that Philly Joe played it R L L, followed by a paradiddle-diddle, like so:
To my knowledge, Philly Joe played it primarily (maybe even exclusively) off the right hand as notated above. But we never miss a chance to create an exercise and work on something in both directions. So, to get familiar with it try releasing with a quarter note and then starting with the left, back and forth:
Once it feels comfortable play it multiple times in a row on each hand until it resolves, and then again, flip it to the other side.
If you're practicing this on the kit, with the hi-hat on 2 and 4, it would be worth shifting the whole by a beat as well to experiment with different placements.
Another thing that Philly Joe would do with this lick is launch into with another single stroke triplet, preceded by an accent eighth note. Again, try this leading both left and right.
And, again, shift that by a beat for more options.
As always, drop my an e-mail if you would like a copy of all of this on a neatly organized PDF