of spur gear 16 is larger than that of spur gear 15 adjacent to spur gear 16 a spur gear 1 5 18 is also mounted non rotatably on shaft 17 and it has a smaller diameter than that of spur gear 16 spur gear 18 meshes with a spur gear 19 which has a larger diameter than that of spur gear 18 in addition to spur gear 19 a spur gear 21 with a smaller diameter than the diameter of spur gear 19 is also located on shaft 20 which extends parallel to shafts 14 and 17 spur gear 21 engages with a second coupling component 22 which is designed as a spur gear second coupling component 22 is capable of being engaged via several axial beveled bolts 23 separated from each other in the circumferential direction with a first coupling component 24 which is also designed as a spur gear recesses for bolts 23 are provided in the end face of first coupling component 24 for this purpose bolts 23 are not shown in the figures first coupling component 24 is located on the same shaft 25 as second coupling component 22 but second coupling component 22 is non rotatably connected with shaft 25 first coupling component 24 is displaceable in the axial direction on shaft 25 a not shown spring is located between the two coupling components 22 24 the not shown spring tries to separate the two coupling components 22 24 i e to disengage them in the engaged state torque is transferred by first coupling component 24 to a spur gear 26 located on a shaft 27 from there torque is transferred further to spur gear 9.