Actuating device for shut-off needles in injection molding devices comprising needle shut-off nozzles

A drive system (10) for shutoff needles in injection molds fitted with needle shutoff nozzles comprises an elevation drive element (20) to which can be affixed at least two shutoff needles (16) of two needle shutoff nozzles, said elevation drive element being displaceable-between two longitudinally supported control rails (30) that can be moved in a first direction (R1)-in a second direction (R2) perpendicular to the first direction (R1), at least two glide elements (50) being configured in grooves (40) oblique to said first and second directions (R1, R2) running between the elevation drive element (20) and the control rails (30), said glide elements converting the first motion of the control rails (30) in the direction (R1) into an elevation motion imparted by the elevation drive element (20) in the second direction (R2). In order to assure in particular substantially maintenance free and durably reliable operation of all valve needles, the invention provides that components which move relative to one another and hence are exposed to wear, in particular the control rails (30) and/or the glide elements (50), are made at least in part of a self-lubricating or a diamantine material or are coated at least in part with a self-lubricating or diamantine material.