Spindle drive apparatus comprising • a guide tube having a longitudinal axis, wherein the guide tube is provided, on one end thereof, with a connection unit for connecting the spindle drive apparatus to a superordinate assembly, i.e. an assembly that is not part of the spindle drive apparatus, and wherein the connection unit is fastened to the guide tube such that it can rotate relative thereto about the longitudinal axis, • a spindle which is provided with an external thread, is housed at least in part in the guide tube, and protrudes out of the guide tube at the other end thereof in each case, wherein a further connection unit is rotationally fixed to the end of the spindle that protrudes out of the guide tube, which further connection unit is intended for connecting the spindle drive apparatus to a further superordinate assembly, i.e. an assembly that is not part of the spindle drive apparatus, • a spindle nut that is fastened to the guide tube and is in threaded engagement with the external thread of the spindle, and • a drive assembly comprising a drive unit, wherein a drive element that is driven by the drive unit surrounds the guide tube and can be rotationally fixed thereto, and wherein the drive unit is supported on a fastening element connected to the superordinate assembly, wherein the fastening element is arranged on the drive assembly, • a helical spring which surrounds the guide tube and the spindle over at least a portion of the length thereof in each case, characterised in that the drive element and thus the drive assembly are arranged to be movable on the guide tube parallel to the longitudinal axis in such a manner that the position of the drive assembly relative to the two connection units (42, 44) can be variably adjusted and the preloading of the helical spring can optionally be modified. • a guide tube having a longitudinal axis, wherein the guide tube is provided, on one end thereof, with a connection unit for connecting the spindle drive apparatus to a superordinate assembly, i.e. an assembly that is not part of the spindle drive apparatus, and wherein the connection unit is fastened to the guide tube such that it can rotate relative thereto about the longitudinal axis, • a spindle which is provided with an external thread, is housed at least in part in the guide tube, and protrudes out of the guide tube at the other end thereof in each case, wherein a further connection unit is rotationally fixed to the end of the spindle that protrudes out of the guide tube, which further connection unit is intended for connecting the spindle drive apparatus to a further superordinate assembly, i.e. an assembly that is not part of the spindle drive apparatus, • a spindle nut that is fastened to the guide tube and is in threaded engagement with the external thread of the spindle, and • a drive assembly comprising a drive unit, • a spindle nut that is fastened to the guide tube and is in threaded engagement with the external thread of the spindle, and • a drive assembly comprising a drive unit, wherein a drive element that is driven by the drive unit surrounds the guide tube and can be rotationally fixed thereto, and wherein the drive unit is supported on a fastening element connected to the superordinate assembly, wherein the fastening element is arranged on the drive assembly, • a helical spring which surrounds the guide tube and the spindle over at least a portion of the length thereof in each case, • a helical spring which surrounds the guide tube and the spindle over at least a portion of the length thereof in each case, characterised in that the drive element and thus the drive assembly are arranged to be movable on the guide tube parallel to the longitudinal axis in such a manner that the position of the drive assembly relative to the two connection units (42, 44) can be variably adjusted and the preloading of the helical spring can optionally be modified.