power harrows equipped with rotary tines
This invention links to a power harrow tine, and to a power harrow equipped with a plurality of rotary harrow tines.
As is well known, power harrows are equipped with rotary harrow tines which are driven in rotation so as to exercise a powerful breaking-up and / or soil crumbling effect, and usually are used after ploughing. Rotary harrow tines need, of necessity, be designed very robustly, both in their ground/soil engaging pieces and also in the manner in which they are positioned on the harrow frame.
It is usual hence for rotary harrow tines to be of one-piece forged composition, and also heat-treated so as to improve the wear resistance of the working tip, and also the fatigue endurance of the entire tine.
The value of forged one-piece harrow tines produces strong and reliable constructions, and which operate well in practice. However, even with forged structures, tip wear does, of course, arise over some time, and with a one-piece construction, it is, consequently, necessary to replace an entire tine when an unacceptable amount of tip wear has happened. The working tip is. of course, only a comparatively small portion of an overall one-piece tine, and typically when about 30% of the overall expansion of the tine has worn away, the whole tine has to be removed (and disposed of as scrap) and followed by a completely new one-piece tine.
Furthermore, existing one-piece cultivator tines are mounted on the harrow frame via proper rotary drive mountings on the frame. When tine replacement is needed, with existing designs, there is not easy entrance to the mountings, and therefore it is not possible for tine replacement to be carried out in the area. This is because it is usually required to go underneath the harrow frame to grasp the mountings, and therefore tine replacement typically has to take place in the establishment.
The invention, therefore, seeks, in one character, to provide an improved rotary harrow tine device which is more economical in its method and replacement, and, in a second aspect, gives a power harrow tool in which tine tip wear is more quickly repaired.
According to one perspective of the invention, there is presented a two part rotary harrow tine having a first part which is modified to be mounted on a respective rotatable mounting on a structure of a power harrow, and a second part having a ground / soil working tip, in which: the first part has a structure mounting portion at one end to be positioned on said rotatable mounting, and a tip mounting portion at its different end; the second part is detachably engageable with said tip mounting part and is releasably securable there to via a single releasable cable; a first one of said tine parts has a pair of protuberances; a second one of said tine parts has two pairs of cells, each recess being of a size to be capable of receiving one of said steps; and, a single fastening hole is performed in either one of displayed first and second tine parts and a set of three fastening holes is stored in the other one of said first and second tine elements; in which:
(a) the second part has resisted working tips provided one at each end thereof, one of the said tips being in a working environment and the other being in an inoperative position;
(b) a middle hole of the assortment of three fastening holes is alignable with the original mounting hole so that the fastener can be exercised through the aligned holes to secure the first and secondary tine parts together, the second part being rotatable through roughly 180°, upon loosening and release of the lock, so that when one tip in the working position is worn, the different working tip can take-up the working class;
(c) the second tine part is movable lengthwise, upon release of the fastener, to increase the alongside projection of a worn functioning tip from the first part, so as to bring each one of the outer holes of the set of three fastening slots into alignment with said single fastening hole to be secured to it via the single fastener; and,
(d) in all adjusted, and turned, positions of the second tine part relative to the first tine part, the two ridges are received by two of the four recesses to ensure the tine parts against relative revolution about the axis of the single fastener. The invention therefore presents a reversibly mounted rotary harrow tine section (the second part) which has opposed operating tips, either one of which can be brought to the working position when required e.g. when unacceptable damage has occurred to the tip presently in the working part. In addition, when inappropriate initial wear has taken place for both functional tips, either one of the active tips can be adjusted to project a more inclusive distance lengthwise of the first tine part, by lengthwise arrangement of the second tine part. Further reversal of the second section then allows the further worn tip to be replaced by an only partially worn tip.
The invention, therefore, provides a rotary harrow tine part in which four separate covering actions may take place i.e. primary and then final wear on each working tip, before the tine part needs to be superseded.