Abstract: Two embodiments of assembly devices particularly adapted for assembling components such as IC chips on a printed circuit board. The arrangement includes a pair of carriages each of which supports gripping means and the supporting and driving arrangements for the carriages permits a very compact assembly and prevents interference between the carriages during their movement. The carriage has an improved supporting arrangement that prevents binding and embodiments are shown wherein the gripping devices carried by the carriages may either pick up units from one or both sides of the device.