Abstract: The invention pertains to a drive system for a utility vehicle (10) containing a motor (12) that is connected to and drives a hydraulic pump (14) which, in turn, is connected to a hydraulic motor (16). The hydraulic motor drives a ground engaging element through a gearbox having different selectable gears. A speed-adjustment device (26, 122) cooperates with the hydraulic pump (14) and/or the hydraulic motor (16) to adjust the rotational speed of the hydraulic motor (16). In order to make available the full rotational speed range of the hydraulic motor (16) in the lower gears while ensuring the observation of the maximum permissible speed in the highest gear, the invention provides a control device to limit the rotational speed of the hydraulic motor (16) to a predetermined value if the highest gear(s) of the gearbox (18) is selected.

Abstract: A crop harvesting machine includes a crop transport or feed mechanism including a feed roller to which a toothed wheel is fixed. A detent in the form of a pivotally mounted lever carries a cam or tooth, the detent being pivotable between a first position wherein the cam is engaged with the toothed wheel so as to block rotation of the feed roller, and a second position wherein the cam is disengaged from the toothed wheel so as to permit free rotation of the crop feed roller. A one-way hydraulic cylinder is coupled to the detent in parallel with a tension coil spring and is controlled by a solenoid control valve, coupled in a control circuit forming part of a metal detector circuit, so as to be pressurized for moving the detent to its first, blocking position when the metal detector sensor senses an undesirable metal object in the crop, and so as to be coupled to sump so that the spring moves the detent to its second position, permitting rotation of the crop feel roller, when no metal is detected.