Patent ID: 8235636

Claim:
A precision kinematic adjustment screw comprising: an externally threaded cylindrical screw having a medial axis, a proximal end and a distal end, wherein the distal end has a torque-applying means that is used to turn the screw, and wherein the proximal end comprises a cavity, a spherical member, a spring, and a spring recess; and wherein the cavity is a cylindrical cut-out in the proximal end of the screw, and the cavity comprises an open end, a closed end, and a radial wall, and the diameter of the cavity is slightly larger than that of the spherical member, such that the spherical member is free to rotate inside the cavity, and wherein at the open end of the cavity a flange extends around the entire circumference of the cavity and forms a circular flange aperture having a diameter slightly less than that of the spherical member, such that the spherical member is axially confined within the cavity, while a semispherical section of the spherical member protrudes beyond the open end of the cavity; and wherein the spring is located within the spring recess, which is aligned with the medial axis of the screw in the closed end of the cavity, and wherein the spring recess comprises an exposed side and an enclosed side, which terminates in a recess wall, and wherein the distal end of the spring engages the recess wall, while the proximal end of the spring extends beyond the exposed side of the spring recess and engages the spherical member, such that the tension of the spring urges the spherical member toward the open end of the cavity and prevents it from engaging the closed end of the cavity.