Downhole adjustable drilling inclination tool

A downhole adjustable drilling inclination tool comprising:

• a piston assembly disposed within an outer housing that is fluidly controlled to move along an exterior surface of a bottom end portion of an inner housing disposed within the outer housing so that a rotatable control ring moves about a guide pin of the outer housing that extends into an interior of the outer housing to hold a neutral, straight, or bent position of the piston assembly corresponding to an amount of compression of a compression spring disposed about an exterior surface of the bottom end portion of the inner housing;
• and
• a tilt housing partially disposed within the outer housing that includes a bolt plate channel configured to receive a bolt plate pin of the piston assembly that travels in the bolt plate channel to tilt the tilt housing by a tilting mechanism that connects the tilt housing to the outer housing and positions the tilt housing in a neutral, straight, or bent position corresponding to the neutral, straight, or bent position of the piston assembly.