US Patent 8469096 Whipstock

A whipstock with a longitudinal axis includes a tapered face surface, at least a part of which is inclined with respect to the longitudinal axis, for guiding a milling head as the milling head passes from a top end to a bottom end of the face surface. A deflecting arrangement protrudes from the face surface and has first and second deflection surfaces. At least a part of each of the deflection surfaces is raised above the face surface, and each of the first and second deflection surfaces are inclined at a greater angle with respect to the longitudinal axis than the face surface in the region of the deflection arrangement. The first deflection surface is located closer to the top end of the face surface than the second deflection surface.