FARM MACHINERY 209 



in which the plows are fastened rigidly together and raised 

 or lowered as a unit. The flexible beam type consists in a 

 heavy triangular frame, carried on wheels, all or a part 

 of which are arranged to castor or are guided by the hitch 



Fig. 118a. Rigid beam gang plow. 



through suitable linkage. The plows are attached to the 

 rear of the frame and are generally controlled by levers ex- 

 tending forward over a platform placed on the frame. These 

 levers may be attached either to a single plow or to a pair. 

 Quite a little variance is found in the location of the gauge 

 wheel which regulates the depth of the furrow. The gang 

 wheel should be so located that the furrow depth will be 

 influenced as little as possible by an uneven surface. 



The "rigid beam" type of tractor plow is used exclusively 

 for the disk gang and is generally confined to small sizes, 

 two to four bottoms when made for moldboard plows. It 

 is desirable with small tractors to have an outfit which may 

 be operated by one man. For this reason the levers are 

 generally turned toward the front where they may be con- 

 veniently reached. Disk tractor plows resemble horse disk 

 gangs except that they are made much heavier. Plows are 

 now made with power lifts enabling the tractor operator by 

 pulling a rope to engage a clutch which sets in motion 

 mechanism which raises the plows by power from the wheels 

 of the gang plow. The power lift is adapted to both the 

 flexible and rigi'd beam types of tractor gangs. 



