Abstract: Torque is normally transmitted between driving and driven members of a ratchet-type slip clutch by a plurality of equiangularly disposed banks of radial pins reciprocably mounted in a cylindrical hub of the driving member and normally spring biased into the bottom of a plurality of equiangularly disposed pockets located in a cylindrical shell of the driven member. Located so as to cooperate to operate completely out of phase relative to the operation of the pins and associated pockets for transmitting torque during normal operation of the clutch so as to maintain positive torque transfer during slipping operation of the clutch is a snubbing mechanism comprising a further set of pins reciprocably mounted in the cylindrical hub and having associated pockets located in the cylindrical shell.

Abstract: A row crop harvester guidance system control circuit comprises a control valve for actuating a hydraulic cylinder connected to the tongue of a pull type harvester responsive either to first and second row crop sensing units mounted on opposite sides of a crop receiving passageway of the harvester or to a manual override switch. The row crop sensing units operate respectively a pair of sensor switches connected in circuit with the control valve. To prevent simultaneous generation of signals by both of the sensor switches, a pair of relays are connected in circuit with the sensor switches and the control valve. The manual override switch is connected in circuit with the relays and generates a control signal for operation of the hydraulic cylinder. The control signal has priority over any contradictory signal generated automatically by either of the sensor switches.

Abstract: A main frame carries a movable part for raising and lowering by means of a hydraulic cylinder, and a blocking member is selectively movable into a position between the piston rod end of the cylinder and a stop on the movable part for preventing accidental descent of the movable part.

Abstract: A pull-type forage harvester has a feed roll transmission shiftable between forward, reverse and neutral modes by means of a pair of identical single-acting hydraulic cylinders connected symmetrically to the rockshaft of a shifting fork and controlled through a solenoid-operated valve controlled electrically from the operator's station of the pulling tractor. Hydraulic connections are such that after completion of shifting from one transmission output mode to another, both hydraulic cylinders are open to a common hydraulic return line. However, inadvertent change of pressure in the return line will not cause shifting of the feed roll transmission as, due to the equal size of the hydraulic cylinders and the symmetrical arrangement of the cylinders with relation to the transmission shifter rockshaft, the shifting effort applied to the rockshaft by the respective cylinders would be equal but opposite, resulting in zero net shifting effort.