as required , detailed embodiments of the present invention are disclosed herein ; however , it is to be understood that the disclosed embodiments are merely exemplary of the invention , which may be embodied in various forms . therefore , specific structural and functional details disclosed herein are not to be interpreted as limiting , but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure . referring to the drawings in detail , a cultivator shank assembly of this invention , generally designated by the reference numeral 1 , includes an upper or first section 5 ; a lower or second section 10 ; clamping means , such as illustrated by l - shaped bracket 15 and bolts 16 , for mounting the assembly 1 on a tool bar 17 that constitutes one transverse member of a conventional farm implement mounting frame ( not shown ); fastening means , such as illustrated by an overlapping assembly generally designated by the reference numeral 20 ; and a ground engaging tool , as illustrated by shovel 23 , for pulling through soil ( not shown ). the first section 5 of the assembly 1 is fixedly attached to the tool bar 17 by the l - shaped bracket or clamp 15 and bolts 16 . the l - shaped bracket has planar legs 25 and 26 joined at bend 29 in a right dihedral angle . leg 25 has an elongated rectangular aperture or slot 30 located near and generally parallel to an edge 32 . the slot 30 is sized to closely receive therethrough a straight planar portion 35 of the first section 5 . the slot 30 is spaced from the bend 29 a distance slightly greater than the length of a top side 37 of the tool bar 17 . leg 26 has a pair of spaced bolt - receiving apertures 40 located near an edge 42 . the apertures 40 are spaced from the bend 29 a distance slightly greater than the height of a forward side 45 of the tool bar 17 . the portion 35 of first section 5 also has a pair of spaced bolt - receiving apertures 48 located near an edge 50 . portion 35 extends through slot 30 and is adjacent to a rearward side 54 of tool bar 17 . the heads of bolts 16 abut against an outer flat surface 55 of portion 35 and bolts - 6 extend through apertures 40 and 48 and are secured by nuts 53 that abut against an outer flat surface 56 of leg 26 . bolts 16 are adjacent to a bottom side 57 of tool bar 17 . portion 35 , legs 25 and 26 and bolts 16 surround and fit snugly about tool bar 17 holding section 5 in place against side 54 and prohibiting any rotational or lateral movement of portion 35 of section 5 during use of the assembly 1 . it is foreseen that other types of clamping means may be utilized to fixedly attach or clamp portion 35 of section 5 to tool bar 17 . first section 5 is a generally flat , rectangular piece of constant cross - section that extends upwardly from the tool bar 17 at portion 35 and is formed into a generally c - shaped portion 58 arching in a forward direction about the tool bar 17 and extends downwardly and rearwardly to a generally straight portion 60 located generally below the tool bar 17 and slightly forwardly therefrom . portion 60 has a bolt - receiving aperture 61 located centrally thereon . an end piece 63 integral with the straight portion 60 is formed by a bend 65 in section 5 . end piece 63 generally projects upwardly and rearwardly from portion 60 at an angle slightly greater than ninety degrees . section 5 includes an elongated slot 68 located at bend 65 . the slot 68 is located generally transversely to the length of section 5 , is generally parallel to edge 69 and is sized to receive therethrough a straight planar upper portion or leg 70 of the second section 10 . slot 68 is spaced centrally in bend 65 between edges 72 and 73 of section 5 . slot 68 is bounded by generally planar surfaces 76 , 78 , 80 and 82 of section 5 . surface 76 is generally parallel to a flat , inner planar surface 85 of straight portion 60 and generally perpendicular to surfaces 78 and 80 . surfaces 78 and 80 are generally parallel and are sized to closely receive edges 88 and 89 of the upper leg 70 of second section 10 . surface 82 is generally perpendicular to surfaces 78 and 80 and is spaced from surface 76 to provide adequate space for extending the upper leg 70 through slot 68 . lower or second section 10 is also made of a generally flat , rectangular piece of constant cross - section similar to section 5 , but of narrower width than section 5 , allowing section 10 to fit within slot 68 of section 5 . both sections 5 and 10 are made from spring steel by conventional forming techniques . upper leg 70 of section 10 has a bolt - receiving aperture 92 located near an edge 95 thereof that extends between a flat upper surface 98 and flat lower surface 100 of section - 0 . upper leg 70 , together with aperture 92 and portion 60 of section 5 , together with aperture 61 and elongate slot 68 , make up the overlapping fastening assembly generally designated by reference numeral 20 . when upper leg 70 is inserted in slot 68 , upper leg 70 is placed adjacent to straight portion 60 of section 5 with apertures 61 and 92 aligned , and a bolt 103 is passed therethrough with a head 105 of bolt 103 abutting against flat surface 55 of portion 60 of section 5 . a nut 108 is secured to bolt 103 and abuts surface 98 of upper leg 70 of section 10 . surface 98 of leg 70 also abuts against surface 76 and is wedged against surface 76 when bolt 103 and nut 108 secure upper portion or leg 70 to section 5 . the frictional forces of surfaces 78 and 80 against edges 88 and 89 , respectively , the frictional force of flat surface 100 against flat surface 85 , and the frictional force of surface 76 against surface 98 hold leg 70 securely against section 5 and prevent rotational or lateral movement of leg 70 with respect to section 5 . corners 112 and 113 formed by the intersection of surface 76 with surfaces 78 and 80 , respectively , are also slightly rounded so that leg 70 wedges securely between surfaces 78 and 80 . leg 70 of section 10 extends downwardly and rearwardly from section 5 and tool bar - 7 . section 10 then curves downwardly and forwardly from leg 70 to a position below and slightly behind tool bar 17 . a lower , forwardly - extending portion 117 of section 10 includes two bolt - receiving apertures 120 for alignment with two bolt - receiving apertures 122 of shovel 23 . bolts 124 and nuts 125 secure the shovel 23 to the lower portion 117 with a shovel point 126 facing in a forward direction . it is foreseen that different types of ground - engaging tools may be secured to lower portion 117 . section 10 of the shank assembly 1 may also be used to cooperate with other mounts , such as the spring - loaded clamping assembly 128 shown in fig3 . upper leg 70 of section 10 is simply secured to a lower portion 130 of the spring - loaded clamping assembly 128 that is securely mounted on tool bar 17 . a spring - loaded clamping assembly 128 is more expensive to build than the upper section 5 of the present invention but may be required for cultivation of particularly rocky soil . when the lower section 10 and ground - engaging tool 23 come in contact with a rock or other obstacle , spring 131 provides flexibility , allowing section 10 to easily trip out of the ground and quickly return to ground engagement once the obstacle is past . in normal use , the shank assembly 1 as shown assembled in fig1 is pulled through the soil with the point 126 of shovel 23 first . sections 5 and 10 flex slightly due to the pull of soil about the shovel 23 . when an obstacle is encountered , the assembly 1 deflects upwardly or slightly to either side . if the obstacle is large or otherwise substantial , the wider , stronger upper section 5 is adapted to remain intact with the narrower , less expensive lower section 10 more likely to stress and either break or bend . if the lower section 10 is damaged , nut 108 is loosened and removed from bolt 103 and bolt 103 is removed from assembly 1 . upper leg 70 of section 10 is then slid in a rearward direction through slot 68 in section 5 . section 10 may either be repaired or a new section 10 acquired and slid forwardly through slot 68 and fixedly attached to section 5 by placing a bolt 103 through apertures 61 and 92 and securing section 10 to section 5 with a nut 108 screwed onto bolt 103 . it is to be understood that while certain forms of the present invention have been illustrated and described herein , it is not to be limited to the specific forms or arrangement of parts described and shown .