The invention relates to agricultural manual implements with teeth, particularly to operating elements of hand cultivators.The operating element 2 of the cultivator 1 contains distributed spiral teeth 3, forming an open circular profile 4 in the plan. The spiral teeth 3 are connected in the upper part to each other in the shape of a regular polygon 5, while the pointed part 6 of the spiral tooth 3 smoothly passes into its remaining cylindrical part 7. The tilt angle of the spiral teeth 3 to the horizon is β=25-45°, the sharpening angle of the teeth is α=20-40°, the angle of rotation of the full penetration of the tooth 3 is γ=40-120°, and the thickness of the cutting edge 7 of the spiral tooth 3 is h=1-3 mm. The invention allows to reduce the fatigue of human muscles during loosening due to easy penetration of the operating element 2 of the cultivator 1 into the soil when it is installed on the soil at the angle δ=60-90° to the horizon while minimizing premature soil subsidence, eliminating the need to repeat cultivation of the same plot.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority from Russian Application Serial Number 2019121417 filed Jul. 5, 2019, which is hereby incorporated herein by reference in the respective in its entirety.

TECHNICAL FIELD

The invention relates to agricultural manual implements with teeth, particularly to operating elements of hand cultivators.

BACKGROUND OF THE INVENTION

There is a prior art hand cultivator (patent RU 85287 U1, published on Aug. 10, 2009) that has an operating element with spiral teeth, which in a plan form a closed profile, while the teeth intersect with each other. This solution is aimed at creating a simple design of a hand cultivator, more technological in manufacturing, mobile in assembly and readjustment, that is, functionally reliable and universal.

The aforementioned cultivator has a disadvantage: the need to press on the tool with your foot when deepening it into the soil.

There is also a prior art cultivator (patent RU 120311 U1, published on Sep. 20, 2012), containing an operating element with curved pointed teeth oriented in the direction of movement of soil loosening and connected at the top to each other in the form of a contour frame with equal sides. Such solution is aimed at reducing the fatigue of human muscles during soil loosening due to easy penetration of the operating element of the cultivator into the soil, which is determined by its special geometry, strength and sharpness of teeth.

The disadvantage of such cultivator is premature eruption of the soil from the operating element when the cultivator is removed from the soil due to insufficient coverage of soil area with the teeth, which, in its turn, leads to the need for repeated cultivation of the soil and, consequently, increases fatigue of the human muscles due to such repeated operation.

There is also a prior art hand cultivator (patent RU 2153787 C1, published on Aug. 10, 2000) with an operating element in the shape of pointed and spatially-arranged spiral-shaped paired teeth of different radii, which are paired, parallel-directed spirals of different radii, directed clockwise. The cultivator is as well equipped with a rotary handle with a vertical shaft, to which the specified operating element is attached. When using the hand cultivator to remove weeds, their roots are cut and cling to spatially-arranged spiral teeth and then are easily removed from the soil. Such technical solution of the tool reduces human fatigue due to the work of various muscle groups during the process of soil loosening, which increases productivity and ease of use.

The disadvantage of this hand cultivator is the need to overcome the high soil resistance when deepening the operating element into it with subsequent rotation of the pointed spatially-arranged spiral-shaped paired teeth of different radii.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

The objective of the invention is to eliminate the aforementioned disadvantages and reduce efforts when loosening the soil.

The technical result of the invention is the reduction of human fatigue when using a cultivator by facilitating efforts to deepen the operating element into the soil. The technical result is as well the minimization of premature soil subsidence, which eliminates the need to repeat cultivation of the same piece of land.

The technical result is achieved in that the cultivator has an operating element with distributed spiral teeth forming an open circular profile in the plan, and in the upper part they are connected to each other in the shape of a regular polygon, according to the invention, the spiral teeth are made with a sharpening angle of 20°-40°, tilt angle to the horizon 25°-45° and the possibility of rotation of the tooth full penetration in the range of 40°-120°.

The spiral tooth has a pointed part smoothly passing into its cylindrical part.

The spiral tooth is made with the cutting edge thickness of 1-3 mm.

The operating element is made with the possibility of installation on the soil at the angle of 60°-90° to the horizon.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

The cultivator1includes an operating element2with spiral teeth3with an open circular profile4connected in the upper part in the shape of a regular polygon5.

The operating element2of the cultivator1is made by forging or precise forging methods. The spiral teeth3are made in the pointed part6with a sharpening angle α=20°-40°, a tilt angle to the horizon β=25°-45°, and with the possibility of rotation of the full penetration of the tooth3in the interval γ=40°-120°. The thickness h of the cutting edge7of the spiral tooth3is equal to 1-3 mm. The operating element2of the cultivator1can be installed on various types of vertical poles8, including telescopic, and those having straight, curved, or S-shaped handles9.

The cultivator1with the aforementioned operating element2works as follows.

The operating element2of the cultivator1is installed on the soil surface at the angle of 60-90°. The pole8is turned with the handle9and the operating element2is immersed in the soil until the spiral teeth3get into the soil, then the cultivator is removed from the soil, the cultivator1is moved to the side and the cycle is repeated. The possibility to install the operating element2of the cultivator1at the angle of 60-90° allows to use it on uneven soil surfaces, including mountainous surfaces, slopes, where it is not possible to install the cultivator1exactly vertically (90°). Such angle of 60°-90° also allows to process very hard soil, since the combination of the aforementioned design features of the operating element2ensures the efficient operation of the cultivator1and is confirmed by the cause-and-effect relation between the design features of the operating element2of the cultivator1and the data on fatigue of the user's muscles which are presented in relation to the need to overcome the soil resistance when cultivating it with the cultivator1and are correlated in the Table below where the teeth3tilt angles to the horizon are 25°-45°, the sharpening angle is 20°-40° in the pointed part6, the angle of rotation of the full penetration of the spiral tooth3is γ=40°-120° and the thickness of the cutting edge7of the spiral tooth3is h=1-3, as well as the smooth transition of the pointed part6of the spiral tooth3into its remaining cylindrical part7, and are associated with the technical result, which lies in reducing the fatigue of human muscles when loosening the soil.

Cultivator operatingelement parameterParameter valueUser's muscle fatigue indicatorTeeth angle to the>25°Low soil resistance, while a large rotation angle of the operatinghorizonelement is required for the full penetration of the teethinto the soil, i.e. it is necessary to make more effort to turn thehandle of the cultivator, sometimes the user has to change theposition of hands: the soil loosens strongly along the closedtooth profile and its premature eruption occurs when shakingthe cultivator.25-45°Weak soil resistance when deepening the operating elementwith the pitchinto the soil, the rotation of the teeth does not require a changeof 1°in the position of the user's hands, which reduces the load onthe user's muscles: the soil with roots clenched in the spiral ofteeth is easily detached and mostly remains there when thecultivator's operating element is removed from the soil.<45°Strong soil resistance when deepening the operating elementinto the soil and at a small rotation angle, which requires a lotof effort from the user's muscles: a part of the soil, clenchedin the spiral of teeth is not detached when turning, which requiresadditional efforts to separate it when shaking the cultivator.Teeth sharpening>20°When the cultivator is deepened, the weeds and roots of plantsanglestring and cling to the teeth, which requires more effort toovercome the soil resistance.20-40°When the cultivator is deepened, the weeds and roots of plantswith the pitchdo not cling to the teeth, but get inside the spiral of teeth withof 1°the soil or get cut from this spiral.<40°When the cultivator is deepened, there is a high soil resistancedue to the low ability of the teeth of the operating element topenetrate into it, which requires more effort from the user.Angle of rotation of>40°The full penetration of the teeth into the soil is not ensured,the tooth fullwhich requires repeated cultivation.penetration40-120°The full penetration of the teeth into the soil is ensured andno change in the position of the user's hands is required.<120°Frequent change of position of the user's hands with furtherrotation of the operating element of the cultivator is needed,so more effort is required from the user.>1 mmWhen the operating element is deepened, roots of plants andweeds string and cling to the teeth, which requires more effortto overcome the soil resistance.Tooth cutting edge1-3 mmWhen the operating element is deepened in the soil, roots ofthicknesswith the pitchplants and weeds do not cling to the teeth and do not abutof 0.5 mmagainst them, so less effort is required from the user.>3 mmWhen the operating element is deepened, roots of plants andweeds do not string onto the teeth, but abut against them andadditional effort is required to overcome the resistance.smooth transition ofWhen the operating element is deepened in the soil, roots ofthe pointed part of the toothplants and weeds do not cling to the teeth, but get inside theinto its cylindrical partspiral of teeth with the soil.

The data in the Table were obtained as a result of numerous tests of cultivator1, with various operating elements2(seeFIG. 1-15) in the field during the work on soil ridging performed by age groups of users from 12 to 70 years old on their garden plots.

It should be noted that for a specialist it is obvious that the invention can be implemented with an operating element2with a different number of spiral teeth3(seeFIG. 1-15), while the operating element2can be installed on various types of vertical poles8, including telescopic, and those having straight, curved, or S-shaped handles9.