My Rig Breaks Apart During Classic Tween. Is There A Way To Keep it Together?

Hello,

I made a rig! It's my first one, so I'm running into a few obstacles. The main one is that I can't figure out how to make my rig stay together. All of the body parts are graphic symbols. But they aren't connected, as I haven't found any wayt to connect them (Is this something I should use the bone tool for?). So any kind of tween that I do with the rig ends up with it breaking apart into several different pieces and not looking very natural at all... 

Any tips on keeping my rig together are GREATLY appreciated. Thanks in advance!