Patent ID: 11885367
Assignee: PHYSIK INSTRUMENTE (PI) GMBH & CO. KG
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 16:
17. A spindle nut and spindle assembly for use with an adjustment device, wherein:
the spindle nut comprises:
an internal thread which is defined by three longitudinal grooves, which run in a direction parallel to a central thread axis A of the spindle nut, which is interruptedby three spaced-apart internal thread segments formed in the spindle nut, and when the spindle nut is in engagement with the spindle, an external thread of the spindle is in contact only with the internal thread segments;
wherein the spindle nut, with respect to a cross section arranged perpendicular to its central thread axis A, comprises a cross section geometry including an inner cross-section curve K facing the central thread axis;
wherein at least inner thread segments each form a partial circle shaped section of the cross-section curve K;
wherein a diameter of each partial circle shaped section corresponds to a core diameter of the internal thread, and the partial circle shaped sections of the cross-section curve K are connected via transition sections to longitudinal groove sections of the cross section curve K which are formed by the longitudinal grooves; and
wherein a distance a between two transition sections adjoining a longitudinal groove section is smaller than a distance b between two transition sections which adjoin a partial circle shaped section; and

the spindle comprises a continuous thread;
wherein the three longitudinal grooves of the spindle nut create three discontinuities between the three spaced-apart internal thread segments of the spindle nut; and
wherein the three discontinuities are shaped to keep the spindle nut from pressing against the continuous threads of the spindle along the grooves, thereby minimizing movement of the spindle within the spindle nut by interrupting the continuity of the compressive stresses that form along the continuous threads of the spindle that cause the spindle to move within the spindle nut during use; and
wherein the spindle and nut maintain a radial clearance between the spindle nut and the spindle when the spindle nut is in engagement with the spindle.