referring to the drawings in detail , where the usual left - right convention is used in which the observer stands behind the machine while facing in the direction of travel , and focusing first upon the triple - disc - gang drawing , fig4 : three concave disc blades 1 are rotatably mounted by being placed upon a triple - disc - gang axle 2 with a pair of sealed bearings 3 ; each of which is pressed into one of a pair of single - bearing hubs 4 and retained by a snap ring 5 . extension convex spools 6 and long concave spools 7 space the assembly which is clamped together with an end washer 8 held by a nut 9 . referring also to fig1 and 2 and noting that concave disc blades , which were indicated as 1 in fig4 , and 6 , are given additional letter identification as 1a , 1b and 1c in order to indicate the function of each disc by virtue of its position on the ridger . a furrowing disc is labled 1a ; a ridging disc is labled 1b ; and a ridge - tilling disc is labled 1c . a ridge - forming disc gang usually comprises a furrowing disc 1a and a ridging disc 1b , although the two functions can be combined in a single - disc gang , particularly , when making a machine for narrow rows . a ridge - forming - tilling disc gang usually comprises a furrowing disc 1a , a ridging disc 1b , and a ridge - tilling disc 1c , although here too , the functions of the furrowing and ridging discs may be combined . the pair of single - bearing hubs 4 may be welded to a pair of gang standards composed of an inner - left , leading - rank gang standard 16 and an outer - left , leading - rank gang standard 18 in order to form the pair of gang support arms for a left , leading - rank , ridge - forming - tilling disc gang 23 . a pair of single - bearing hubs 4 may be welded to a pair of gang standards composed of an inner - right , leading - rank gang standard 17 and an outer - right , leading - rank gang standard 19 in order to form the pair of gang support arms for a right , leading - rank , ridge - forming - tilling disc gang 21 . in the double - disc - gang drawing , fig5 two disc blades 1 are rotatably mounted by being placed upon a double - disc - gang 10 with a pair of sealed bearings 3 which are pressed into a dual - bearing hub 11 and held against a spacer 12 by a short concave spool 13 and a short convex spool 14 . the assembly is clamped together with and end washer 8 held by a nut 9 . referring to fig1 and 2 , a dual - bearing hub 11 is welded to an outer - right , leading - rank gang standard 19 in order to form the gang support arm for the right , leading - rank , ridge - forming - tilling , partial disc gang 23 . a dual - bearing hub 11 may be welded to a left , trailing - rank gang standard 24 in order to form the gang support arm for a left , trailing - rank , ridge - forming disc gang 26 . a dual bearing hub 11 may be welded to a right , trailing - rank gang standard 25 in order to form the gang support arm for a right , trailing - rank , ridge - forming disc gang 27 . in the single - disc - gang drawing , fig6 a disc blade 1 is rotatably mounted by being placed upon a single - disc - gang axle 15 with a pair of sealed bearings 3 which are pressed into a dual - bearing hub 11 and held against a spacer 12 by the axle 15 and a short convex spool 14 . the assembly is clamped together with an end washer 8 held by a nut 9 . referring to fig1 and 2 , the dual - bearing hub 11 is welded to a left , trailing - rank gang standard 24 in order to form the gang support arm for the parting - furrow - complemental disc gang 28 . the gang standards 16 , 17 , 18 , 19 , 24 , and 25 are made from rectangular structural tube and are welded to a transverse main frame 29 made from square structural tube . provision for attachment of the transverse main frame 29 to a tractor hitch includes a top - link mast 30 ; composed of two mast sides 31 with a mast spacer 32 welded between them ; and a left lower - link bracket 33 and a right lower - link bracket 34 , each of which is constructed from a pair of hitch sides 35 with a hitch spacer 36 welded between them . the top - link mast 30 and the lower - link brackets 33 and 34 are welded to the transverse main frame 29 . a parting line 37 is drawn through the center of the tilling ridger in fig1 . though the drawings , fig1 and 2 , appear to show that the furrowing disc 1a of the left , leading - rank , ridge - forming - tilling disc gang 20 that is mounted over the parting line 37 may be touching the rear surface of the ridging - disc 1b of the right , leading - rank , ridge - forming - tilling , partial disc gang 23 , it is important that a clearance of about one - half inch or more be maintained between the discs in order to prevent contact . if the discs are allowed to interfere , especially through a layer of mud , it can slow the rotation of the furrowing disc 1a and lead to clogging because the tangential velocity at the circle of contact on the ridging disc 1b is much less than the tangential velocity of the outer edge of the furrowing disc 1a . clearance is obtained by moving the ridging disc 1b closer to its adjacent ridge - tilling disc 1c .
a disc ridger having an arrangement of disc gangs that substantially eliminates sidewise draft or clogging tendencies found in previous disc ridgers , also incorporating additional discs located for completing the tillage of the area swept by the disc ridger is described .