Soil working tines

Abstract

A tine on a rotary harrow has an upper fastening portion and a lower soil working portion which portions meet at a junction. The fastening portion is tapered to be tightly held in a holder without turning and has an upper threaded end that receives a nut and a lower, multi-sided region that merges into a similar region at the top of the soil working portion. The junction has an enlarged cross-section that preferably is hexagonal and towards the lower tip of the soil working portion, the cross-section changes into a generally rectangular cross-section region. When placed in a holder, the junction is located at the lower end of the holder and the longitudinal axes of the two portions are angled to one another. Also, a rib is located at the leading side of the soil working portion and grooves are formed in the leading flat sides thereof. Grooves of lesser magnitude are formed in the trailing sides of the soil working portion relative to the direction of intended rotation.

Description

Claims

1. An elongated tine for a rotary harrow comprising a substantially straight upper fastening portion and a substantially straight lower soil working portion that terminates in a lower tip, said fastening portion having a lower first tapering part and an adjoining upper second tapering part, each of said parts tapering inwardly and upwardly towards a screw threaded portion located at an upper free end of the fastening portion, said first part adjoining an integral junction with said soil working portion and said second part being located between said first part and said screw threaded portion, said first part more steeply tapering inwardly than said second part and each said part having a substantially conical configuration, said second part extending for substantially at least half of the length of said fastening portion.

2. A tine as claimed in claim 1, wherein the cone angle of said first tapering part is about 30.degree..

3. A tine as claimed in claim 1, wherein both of said tapering parts are polygonal in cross-section and multi-sided.

4. A tine as claimed in claim 1, wherein the greatest cross-sectional area of said tine is at said junction between the fastening and soil working portions and said cross-sectional area being hexagonal in shape.

5. A tine as claimed in claim 4, wherein the hexagon defined by said cross-sectional area is a regular hexagon.

6. A tine as claimed in claim 4, wherein said hexagonal cross-section of the tine continues upwardly from said junction into a region of said fastening portion.

7. A tine as claimed in claim 1, wherein said soil working portion, from said junction, progressively changes into a lower region of said soil working portion that is substantially rectangular in cross-section adjacent said lowermost tip.

8. A tine as claimed in claim 4, wherein the transition from said hexagonal cross-section to said rectangular cross-section of said soil working portion is substantially complete at a location substantially one-third of the distance along the length of said soil working portion from said junction.

9. A tine as claimed in claim 7, wherein, as seen in cross-section, at least one corner of said soil working portion is flattened along its length, said flattened corner forming a rib which extends for substantially the entire length of said soil working portion, said rib being located at the leading side of the tine with respect to the intended direction of operative rotation thereof.

10. A tine as claimed in claim 7, wherein grooves are formed in all four sides of the lower region of the soil working portion that has a rectangular cross section, said grooves extending upwardly from said tip, and two grooves at the front of said tine, with respect to the intended direction of operative rotation thereof, being of greater length than those two grooves at the rear of said tines with respect to said direction, the depth of the front grooves being different than the depth of the rear grooves.

11. A tine as claimed in claim 1, wherein the opposite ends of said second part have cross-sections which are angularly offset relative to one another by about 30.degree. around a longitudinal center line of said fastening portion.

12. A tine as claimed in claim 1, wherein said screw-threaded portion is substantially circular in cross-section.

13. An elongated tine for a rotary harrow comprising a substantially straight upper fastening portion and a substantially straight lower soil working portion that terminates in a lower tip, the longitudinal axes of said fastening portion and working portion being inclined to one another, said fastening portion having a lower first tapering part and an adjoining upper second tapering part, each of said parts tapering inwardly and upwardly towards a screw threaded portion located at an upper free end of the fastening portion, said first part adjoining an integral junction with said soil working portion and said second part being located between said first part and said screw threaded portion, said first part more steeply tapering inwardly than said second part and each said part having a substantially conical configuration, said second part extending for substantially at least half of the length of said fastening portion.