GB1351806A - Hydraulic systems for the height adjustment of cutting platforms of combine-harvesters - Google Patents

Abstract

1351806 Combine harvester hydraulic system INTERNATIONAL HARVESTER CO 19 April 1971 [27 Feb 1970] 22682/71 Heading A1F [Also in Division F1] A cylinder 12 and plunger 13 together constitute jack 5 for lifting cutting platform 1. The hydraulically operated stop 15 for the plunger 13 is adjustably positioned by oil under pressure from pump 23 and passed via distributor 26, and pipe 42 which connects fluid chamber 19 to distributor 26 when the 3 way valve 25 is in position shown in Fig. 1. The unit is fitted with an oleo-pneumatic accumulator 51 containing a liquid phase 52, gaseous phase 53 and a leak tight membrane 54. Phase 52 is connected by pipe 56, fitted with a needle valve 57, to a 3 way reversing valve 58 which serves to provide fluid communication between accumulator 51 and either circuits 24 or 42 thus providing float action directly to rod 13 or via the stop 15 to plunger 13. The needle valve 57 serves to disengage the float action of the jack by isolating the accumulator 51 from circuit 24 or 42 depending on the adjustment of valve 58. The manually operated, three position distributor 26 serves to drain fluid from circuit 24 or 42 through 39 and 32 when distributor lever is in position D, to isolate pump 23 when in position N, and to inject fluid into the system via channel 27 and 38 when lever is in position M. Valve 25 serves to provide fluid connection between distributor 26 and either circuits 24 or 42.