In the inventive device, contact components (3) are secured in the form of strips to a rear duct-type support (2) in a stacked arrangement. The contact components (3), when seen from said stacked arrangement, are bevelled (7) in such a way that they taper towards the rear. This enables the contact components to be arranged next to each other at a narrow lateral distance from each other in a concentric arrangement of several supports (2).
