angle-brace

from The Century Dictionary.

• noun In carpentry: A piece of timber having its two ends fixed to the two pieces forming adjacent members in a system of framing, and subtending the angle formed by their junction.
• noun An instrument consisting of a rectangular crank-frame, like the carpenter's brace (see brace), but usually much stronger, carrying a parallel tool-spindle which ends in a pad or bit-socket of the ordinary form, and carries a small bevel-wheel gearing into a second wheel on the axis of a winch-handle, by which motion is communicated to the drill.