1. A fixing apparatus (10) for fixing one or more printed circuit boards (30) to a housing wall (22) and havinga frame part (11) having a longitudinal recess (13) therethrough,
locking means (23) for fixing the frame part (11) to the housing wall (21), and
a wedge body (12) displaceably supported within the recess (13) of the frame part (11), wherein
the wedge body (12) comprises around an outer surface thereof, a plurality of sequentially connected wedge-like individual segments (12a, 12b, 12c, 12d, 12e, 12f) each having a symmetrical wedge shape with slanted planes converging in a longitudinal direction (14) until the next wedge-like segment directly adjoins, and
the recess (13) through the frame part (11) comprises an outer edge configured to exactly fit the shape of the slanted planes of the individual wedge-like segments (12a, 12b, 12c, 12d, 12e, 12f), such that
the wedge body (12) is longitudinally displaceable (14) into a position relative to the frame part (11) in which a compressive force (F) applied to the frame part (11) by the wedge body (12) deforms the outer surface of the frame (11) at least regionally outwardly.