Patent GB-706396-A (GB)
Title: Improvements in or relating to agricultural machinery
IPC: A01F12/30
Filed: 1950-03-21
Abstract: 706,396. Thrashing-machines. HOWLETT, C. W. May 25, 1951 [March 21, 1950], No. 7066/50. Class 58 In or for a combine harvester, a separating means including a straw walker, means for imparting circular motion to the latter at one point, an inclined pin and slot connection between the straw walker and a support, the connection being spaced from the means for imparting circular motion, and the slot of the connection being arranged so that during operation the straw walker, at the pin and slot connection, is caused to move up and down, and the arrangement being such that in operation the straw walker moves to convey the straw. As shown a straw walker 25 consisting of a plate portion 25A with teeth 27 on its upperside located beneath and disposed substantially parallel to a grill 23, through which the teeth 27 project rigidly secured to the framework 1 of the machine and extending upwardly and rearwardly from the rear edge of the concave 11, formed in upper and lower portions 11A, 11B pivoted together at 12, and a long rectangular rack 26 disposed substantially horizontally and extending from the plate portion 25A to the rear of the machine. The plate portion 25A is connected via a slotted link 28 and roller 45 carrying lifting arm 44 to a shaft 43 to which also a two armed lever 42 is attached, the free end of the arm 42A of the latter being pivotally connected to a connecting rod 41 whose other end is secured to a pin 40 eccentrically mounted on a wheel mounted at one end of a crank shaft 39 (the other end having a driving pulley, not shown) which is pivotally connected by a crank pin 38 to the rear end of the straw walker. The free end of the other arm 42B of the two armed lever 42 is pivotally secured to a riddle 32 near its forward end which extends from beneath its concave 11 towards the rear of the machine, the rear of the riddle being secured to the lower end of a spring 46 the upper end of which is bolted to the framework 1. A chute 47 located below the straw walker 25 directs grain dropping through the latter on to a sieve 33 comprised in the riddle through which the grain 51 and chaff 52 may drop and pass through further sieves 34 when it is subjected to a blast of air from a fan 35 controlled by a deflector 36 for separating the grain and chaff. An elevator 7 pivotally secured at 15 to the frame 9 on which the threshing drum 8 is rotatably mounted carries at its forward end a cutter bar 6 whose height above the ground can be varied by movement about the pivot occasioned through a castor 57, running over the ground immediately below the cutter, anl via levers 56, 55 attached thereto and to a lug 54 of a yoke 20 rotatably mounted on a shaft 19 and carrying a worm 21, turnable by a handle 22, meshing with a wheel 18 to which an arm 17 itself attached to an arm 16 pivotally attached to the elevator at 16A is attached, both the wheel 18 and the arm 17 being freely rotatable on the shaft 19, the arm 17 moving with the yoke 20 unless the handle 22 is turned to alter the relative angular disposition between the arm 17 and the yoke. More than one straw walker may be employed located side by side and driven by a common crank shaft preferably out of phase with each other.