62 which creates an open space 66 between jacket surface 58 and motor housing 18 in which sliding switch 20 may be moved at a sufficient distance away from stator 50 a dimension x 2 which represents the distance between flat section 60 and the small gap on side 64 is designed to be asymmetrical around separating line 68 pole horns 36 a 36 b of pole halves winding holder 36 with the larger winding width x 3 are designed to be shorter in length than pole homes 38 a 38 b of the pole halves winding holder 38 with the smaller winding width x 1 if stator 50 in this embodiment would be symmetrical around separating line 68 on side 62 the embodiment would correspond to that of a two pieced field core with pronounced flat sections on the side and a large winding width stator 50 has u2014 in the region of flat section 60 and therefore in the region of the larger winding width x 3 on the pole axis in the center of winding holder 36 u2014 a thinner wall thickness 72 while wall thickness 74 on the pole axis of winding holder 38 is greater in the region of smaller winding width x 1 as an option stator 50 may be divided axially into two halves 76 78 as indicated using dashed lines on diametrically opposed separating points 70 flat section 60 is located entirely.