Patent GB-709507-A (GB)
Title: Improvements in or relating to cutter mechanisms for harvesting machines
IPC: A01D45/10
Filed: 1952-10-20
Abstract: 709,507. Sugar-cane harvesters. INTERNATIONAL HARVESTER CO. Oct. 20, 1952 (Nov. 2, 1951], No. 26249/52. Class 6 (3) Cutter mechanism for harvesting stalk crops such as sugar cane comprises a frame carrying a cutter disc at the base of a substantially vertical shaft, and means which locate the shaft in relation to the frame and which include rotational driving means responsive to the torque load on the cutter to permit or effect vertical movement of the shaft relative to the frame for raising or lowering the cutter. The machine shown comprises a frame 11, 12, 12a supported at the front by steerable wheels 15, 16 whose yokes 17, 18 are fixed to shafts 19, 21 journalled in sleeves 20, 22 which can slide vertically in the frame members 12, 12a. To permit all four wheels of the frame to remain in contact with the ground the sleeves 20, 22 are linked to a bar 23 which is connected at 37 to a hydraulic cylinder 32 whose piston rod is connected to the frame member 12a. The linkage is such as to permit slight variations in the level of the wheels. The harvesting elements of the machine comprise disc cutters 46, 47 and associated conveying augers, all carried by slightly inclined shafts carried by hinged arms 58 whose rear ends are carried by links permitting the arms to swing back slightly, thus enabling the cutter shafts to swing backwards when the cutters meet an obstacle. The upper ends of the shafts are threaded and, in housings 95, 101, the threads are engaged by sleeve nuts carrying bevel gear wheels. The pitch of the thread on each shaft is such that in normal use the bevel wheel drives the shaft through the sleeve nut, but when a predetermined torque load is not reached or is exceeded the shaft will move downwards or upwards with respect to the nut. This predetermined load is adjusted by a handcontrolled valve regulating the supply of fluid to a cylinder which is movable about the same axis as the arms 58, and which can vary the tension of springs connected to a slide guided in tracks secured to the arms 58. Spaced links 134 are connected to the slide and are pivoted to the main frame ; thus, these links under the influence of the springs tend to move downwards thereby to cause a downward movement of the harvesting implements. The canes prior to cutting are bent forwards by a drum 81 and after being cut by the cutters 46, 47 and lifted by the augers 50, 51 are propelled rearwardly by a roll 71 to be engaged by rolls 75, 76 which deliver them to a trailing wagon. The mechanism described above serves to position the cutters in relation to the main frame as the result of varying torque loads produced by undulations of the ground. When undue resistance is met, hte arms will rise and move a rod 145 carrying a member 150 which then closes a switch 151 which is in series with a normally closed switch 155 arranged above the bar 23, and a solenoid is thereby energized to open a valve in circuit with the cylinder 32. By this means the frame of the machine is lifted and in doing so will eventually cause the arm 23 to strike an arm on switch 155 to open the circuit, and the operating valve then returns to its neutral position. Other switches 152, 156 are similarly arranged to function in a similar manner when the arms 58 move in the opposite direction.