Foldable harrow

Claim 1

A harrow device characterized by including (i) a supporting frame adapted to be connected to a draft source, said supporting frame having a plurality of laterally positioned rigid supporting sections, each hinged to its laterally adjacent section, said supporting frame being composed of an inboard section and two outboard sections, one of which is on each side of the inboard section; (ii) a plurality of working sections corresponding to the respective supporting sections, said working sections each comprising (a) a plurality of tandemly positioned elongated transverse harrow bars secured together for independent vertical and pivotal motion with respect to each other, and (b) a plurality of downwardly disposed harrow teeth secured to said harrow bars; (iii) connecting means flexibly securing the working sections to their corresponding supporting sections so that when a working section is in harrowing position it underlies its corresponding supporting section; (iv) first fluid actuated driving means connected between one of the outboard sections of the supporting frame and the inboard section of the supporting frame, and second fluid actuated driving means connected between the other outboard section of the supporting frame and the inboard section of the supporting frame so that each one of the outboard supporting sections together with its corresponding working section can be independently rotated as a unit around a longitudinal axis between prone and upstanding positions; (v) butt plates positioned between and carried by the respective laterally adjacent sections of the supporting frame, said butt plates being in registration when the supporting frame is in prone position; said driving means of (iv) being adapted to force and maintain said butt plates in registration when the supporting frame is in prone position and at other preselected times to effect the rotation of the outboard section of the supporting frame and its corresponding outboard working section as specified in (iv); (vi) individual spacer means mounted on the undersides of the respective supporting sections so that each spacer means is interposed between a supporting section and its corresponding working section, said spacer means separating the supporting section from its underlying working section by a predetermined distance when the harrow device rests in prone position upon a flat surface; and (vii) attachment means mounted on the forward end of the inboard section of the supporting frame enabling the entire supporting frame to be detachably attached to and propelled by the draft source and to be raised and lowered by and tilted forwardly and rearwardly by driving means of the draft source; the connecting means of (iii) being further characterized in that they are linearly extendible to a predetermined length such that when the supporting frame is raised by driving means of the draft source, working sections in prone positon can be suspended below their corresponding supporting sections by a predetermined distance substantially in excess of the predetermined distance of (vi).