Chisel plow

Claim 1

An earth working apparatus having a rigid frame mounted on supporting wheels and carrying a plurality of earth working devices, a draft tongue having a pivotal mounting on said frame adapted to be hitched to a towing vehicle, said draft tongue having an extension thereof inwardly of said frame beyond said pivotal mounting, a vertically disposed wheel mount for each of said supporting wheels, a rotary crank axle mounted transversely on said frame having a horizontal axis, a longitudinally extending link connecting each of said wheel mounts with said rotary crank axle, said links each comprising a crank arm operative from said crank axle, a second longitudinally extending link vertically spaced relative to each of the first links, said second links being parallel to the first links and of the same length as the first links and respectively connecting said wheel mounts with a respectively associated axle mounted on said frame having a horizontal axis in vertical alignment with the axis of said rotary axle whereby said respective wheel mounts are constrained to vertical movement in respectively vertical positions throughout their extent of travel between raised and lowered positions, power means to rotate said crank axle whereby said first links comprise laterally spaced crank arms to impart vertical movement of the wheel mounts, said second links acting to maintain the vertical position of each wheel mount during movement between said raised and lowered positions, an upper crank arm provided on the crank axle disposed intermediate said first links, said power means having operative engagement at one end thereof with said upper crank arm to rotate the crank axle, a pivotal connection at the opposite end of the power means on said frame, a telescoping link connection extending between said upper crank arm and said frame to limit rotation of the crank axle in a direction that lowers the frame relative to said wheel mounts to fix the operating height of said earth working devices for the operations of said apparatus, a depending crank arm centrally disposed on said crank axle, and a link connecting said depending crank arm with said inward extension of said draft tongue to compensate for adjustments in height of the frame to effect normal hitching to said towing vehicle and maintain the frame and draft tongue substantially level upon rotation of the crank axle.