Unwanted deformation by changing the pose of armature I have a mesh (an operation table), like a normal operation table, just the top part(cushion part) can be bent and because of that, I put an armature inside the mesh.
What I want to have at the end is that the top part of the table can be bent, but the bottom part, the cantilever, shouldn't be deformed when I rotate the bone of the top part (x-axis top when you see it at the pic). The problem is that when I rotate the top part, the bottom part of the mesh is actually moving along the deformation of the top part of the mesh. How can I set the armature so that the bottom part isn't deformed along?

Blend file
  

This is the bone (It won't show even with the X-Ray mode)

The bottom part (the reverse T part of the table shouldn't be deformed - Just stay like it is).
  How should I put the weight or edit the armature? I haven't got the hang of weight of the armature.
Okay, so we have no idea what you did to this to get it this whacked out, but first of all, I went to the object menu, and cleared the armature from the table's parent.

Notice that the table flies across the entire world after doing this.

IN OBJECT MODE with no weight paints, or anything else going on, get the table and the armature in generally the same spot as each other using G (translate).

Next, select the table, and then the armature. Hit Ctrl+P > with automatic weights. This fixes most of the problems.

You may need to do some veeery minor weight painting, but don't go overboard 'cause it's real easy to mess up with the weight paint.