Patent GB-1188502-A (GB)
Title: Improvements in or relating to Combine Harvesters
Inventor: JARVIS JOHN STEVENS
IPC: A01D41/127
Filed: 1966-04-28
Abstract: 1,188,502. Combine-harvesters. RANSOMES SIMS & JEFFERIES Ltd. 24 April, 1967 [28 April, 1966], No. 18775/66. Heading A1F. [Also in Division F2] In a self-propelled combine, grain-recovery means are disposed to the rear of the straw-rack 26, so as to recover grain entrained in the mass of straw leaving the rack, and means are provided responsive to the rate of flow of the recovered grain which either provide an audible or visible signal to the driver of the machine or directly control the forward speed thereof. The main parts of the combine are conventional and comprise a header 6 with a reel 8 adjustable in two directions by hydraulic jacks 10, 12; crop is fed from the header by an elevator 18 to the drum 20 and concave 22 the threshed grain passing via a dressing shoe 24 and elevator 76 to the grain tank 78, whilst straw is discharged rearwardly over an oscillating straw-rack 26. Beyond the rack is an open work grid 37 surmounted by a tined drum 32 which teases the straw-mat and permits loose grain to fall therethrough on to a tray 44 sloping to an auger 46 which feed the grain and cavings into a graincleaner 48. The cleaner (Fig. 2) comprises a cylindrical foraminous screen 60 through which the grain is urged by rotary vanes 62, to fall through a funnel 56 while subjected to a winnowing action by a fan 58 which blows chaff rearwardly out of the machine. An auger 68 carries the cleaned grain forwardly to fall through a tube 70 into the inlet of the grain elevator 76. The tube 70 contains a flap-valve 100 pneumatically connected to a hydraulic system ((Fig 4) for controlling the forward speed of the harvester. The harvester engine 144 drives the front wheels 2 of the machine through an endless-belt transmission 158 having two variable-diameter sheaves 160, 162 one of which 162 is spring loaded and the other is controlled by a hydraulic ram 166. The ram is connected through a spring-loaded multi-port sliding valve 168 to an engine-driven pump 170 and hydraulic reservoir 172. The valve-side is connected by a link to a rocker 182 pivoted at 184, the other arm being connected through a spring-loaded composite link 148 to the diaphragm of a capsule 126. The lower side of the diaphragm is open to atmosphere and the upper side is subjected to reduced pressure from the engine inlet-manifold. The flap valve operates a spring-loaded ball-valve (Fig. 5, not shown) in a conduit 124 leading to the capsule-diaphragm, so that an accumulation of grain in the tube 70 depresses the flap-valve 100, opens the ball-valve, admits air above the diaphragm, which flexes downwardly to tilt the rocker 182 in a direction to move the valve-slide 168 so as to energize the ram to reduce the gear-ratio of the belt-drive 158 to the vehicle-wheels 2. Accordingly, the harvester-speed is reduced until the grainaccumulation in the tube 70 disappears; thereafter, it remains at that speed. The lost-motion link 148 permits manual adjustment of the speed without affecting the automatic speed-adjustment. In modifications, the sensing of grain-accumulation may be effected photo-electrically and the speed-reduction may be effected in a stepwise manner through the interposition of an electromagnetic timing mechanism.