Patent ID: 8899121

Claim:
A spindle drive comprising a threaded spindle that can be rotationally driven, a carriage displaceable via the threaded spindle along a guide rail, as well as several guide carriages arranged in a direction of a spindle axis to support the threaded spindle, with the guide carriages arranged in a feed direction being pushed together successively by the carriage and being moved towards an end of the spindle, and with the guide carriages arranged in a direction opposite to the feed direction being entrained via a coupling means and being moved into an allocated support position, the coupling means are provided arranged on the guide carriages and the carriage and cooperating therewith, which are operable by switching means arranged fixed on the guide rail by which the guide carriages arranged in the feed direction can be automatically coupled with a respective one of the carriage or guide carriages in a subsequent displacement motion and by which entrained ones of the guide carriages upon reaching their respective support positions are automatically decoupled and placed, wherein the coupling means comprises a first coupling element provided on each of the guide carriages, which cooperates with a second coupling element arranged on at least one of the guide carriage or the carriage in an accumulating motion, with one of the coupling elements of a pair of the coupling elements being switchable between a locked position and an unlocked position, and the switching means comprises a switching ramp arranged on the guide rail in each area of a support position for the guide carriages, which switches the switchable coupling element of the guide carriage allocated to said support position during the displacement out of said support position into its locked position and during the displacement into the support position into its unlocked position, wherein the second coupling element is embodied as a locking pin arranged fixed on at least one of the guide carriage or the carriage, extending in the accumulating direction, which penetrates into a receiving bore of the guide carriage being coupled, and the first coupling element comprises a latch, adjustable perpendicularly to an axis of the locking pin that is engageable with a latching groove on the locking pin, which is operated via a switching cam arranged thereat and cooperating with the switching ramp in the unlocking direction, and the guide rail is U-shaped in cross-section, and the switching ramp is provided on a separate switching bar that is inserted into an allocated recess on an inside of a lateral wall of the guide rail.