SEED PRESS WHEEL

Abstract

Seed press wheel for sowing units for precision seeders. The seed press wheel includes a solid tire in the shape of a disc that has a hole or central axis for mounting the tire on a hub. The solid tire has a first portion extending radially from the central axis, and a second portion extending radially from the first portion, the first portion being made of a first material having a first modulus of elasticity value, and the second portion being made of a second material having a second modulus of elasticity value, the first modulus of elasticity value being different from the second modulus of elasticity value.

Claims

1. A seed press wheel for sowing units for precision seeders, comprising a solid tire in the shape of a disc that has a predetermined axis for mounting the tire on a hub, the solid tire including a first portion extending radially from the axis, and at least one second portion extending radially from the first portion, wherein the first portion is made of a first material having a first modulus of elasticity value, and the second portion is made of a second material having a second modulus of elasticity value, the first modulus of elasticity value being different from the second modulus of elasticity value.

2. The seed press wheel according to claim 1, wherein the first modulus of elasticity value is greater than the second modulus of elasticity value.

3. The seed press wheel according to claim 2, wherein the first modulus of elasticity value is between 2.5 and 3.5 MPa, and the second modulus of elasticity value is between 0.5 and 1.5 MPa.

4. The seed press wheel according to claim 3, wherein the first material has a modulus of elasticity of 3.2 MPa and the second material has a modulus of elasticity of 0.9 MPa.

5. The seed press wheel according to claim 1, wherein the first portion has an annular configuration and defines a bead zone of the solid tire, and the second portion is annular and is located in an intermediate zone between the bead zone and a tread zone of the solid tire, the bead zone, the intermediate zone and the tread zone being contiguous in pairs and respectively being radially arranged from closest to furthest away with respect to the axis.

6. The seed press wheel according to claim 5, further comprising a third portion that has an annular configuration and is made of a third material having a third modulus of elasticity value between the first modulus of elasticity value and the second modulus of elasticity value.

7. The seed press wheel according to claim 6, wherein the intermediate zone has a tapered configuration so as to converge away from the bead zone and is made of the second material.

8. The seed press wheel according to claim 6, wherein the intermediate zone has a tapered configuration so as to converge away from the bead zone and is made of the third material.

9. The seed press wheel according to claim 8, wherein the intermediate zone having a tapered configuration comprises shoulders having connection surfaces between the intermediate zone and the tread zone, and the angle formed between the shoulders is 22.

10. The seed press wheel according to claim 1, wherein the hardness of the first material is between 60 and 80 Shore A and the hardness of the second material is between 35 and 50 Shore A.

11. The seed press wheel according to claim 1, wherein the solid tire has a dimensional ratio between its maximum diameter and its maximum thickness between 5 and 15.

12. A seeder comprising a seed press wheel including a solid tire in the shape of a disc that comprises a central hole, a first portion which is made of a first material having a first modulus of elasticity value, and a second portion which is made of a second material having a second modulus of elasticity value, the first modulus of elasticity value being different from the second modulus of elasticity value.

13. A method for producing a seed press wheel for a seeder according to claim 1, comprising: providing a mold for producing the solid tire comprised in the seed press wheel, injecting or pouting the first material into the mold in order to produce the first portion of the solid tire having the first modulus of elasticity value, injecting or pouring the second material into the mold in order to form the second portion of the solid tire having the second modulus of elasticity value that is different from the first modulus of elasticity value, and finishing forming the solid tire and extracting it from the mold.

14. The method according to claim 13, further comprising injecting or pouring a third material into the mold, before or after the injection or pouring of the second material, the third material having a third modulus of elasticity value between the first modulus of elasticity value and the second modulus of elasticity value.

15. The method according to claim 14, further comprising: forming the first portion with an annular configuration defining a bead zone of the solid tire; and forming the second portion with an annular configuration defining an intermediate zone between the bead portion and a tread zone of the solid tire, said bead zone, the intermediate zone and the tread zone being contiguous in pairs and respectively being radially arranged from closest to furthest away with respect to the axis, wherein the intermediate zone with a tapered configuration converging away from the bead zone and being made of, or of a material similar to, second material or the third material.

16. The seed press wheel according to claim 1, further comprising a third portion that has an annular configuration and is made of a third material having a third modulus of elasticity value between the first modulus of elasticity value and the second modulus of elasticity value.

17. The seed press wheel according to claim 5, wherein the intermediate zone has a tapered configuration so as to converge away from the bead zone and is made of the second material.

18. The seed press wheel according to claim 5, wherein the intermediate zone has a tapered configuration and comprises shoulders having connection surfaces between the intermediate zone and the tread zone, and the angle formed between the shoulders is 22.

19. The seed press wheel according to claim 6, wherein the intermediate zone has a tapered configuration and comprises shoulders having connection surfaces between the intermediate zone and the tread zone, and the angle formed between the shoulders is 22.

20. The seed press wheel according to claim 7, wherein the intermediate zone comprises shoulders having connection surfaces between the intermediate zone and the tread zone, and the angle formed between the shoulders is 22.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The features and advantages of the invention will become clearer from the detailed description of an exemplary embodiment, shown by way of non-restrictive example and with reference to the drawings, in which:

[0041] FIG. 1 is a view from the side of a seed press wheel,

[0042] FIG. 2 is a view from the front of the wheel of FIG. 1,

[0043] FIG. 3 is a sectional view of the wheel of FIG. 1 in the plane III,

[0044] FIG. 4 is a view from the side of a solid tire of the wheel of FIG. 1, and

[0045] FIG. 5 is a sectional view of the solid tire of FIG. 4 in the plane V.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0046] In FIG. 1, reference sign 1 denotes a seed press wheel for sowing units of precision seeders. The seed press wheel includes a solid tire 2 in the shape of a disc that has a central hole 3 for mounting the tire on a hub 4. The solid tire 2 preferably has a first portion 7 extending radially from the central hole 3 and a second portion 8 extending radially from the first portion 7, the first portion 7 being made of a first material 7a having a first modulus of elasticity value E1, and the second portion 8 being made of a second material 7b having a second modulus of elasticity value E2, the first modulus of elasticity value E1 being different from the second modulus of elasticity value E2.

[0047] With reference to FIGS. 1, 2 and 3, it is clear that the central hole 3 preferably also has the shape of a disc.

[0048] An axis of rotation X of the seed press wheel 1 is preferably found at the center of the central hole 3.

[0049] The first modulus of elasticity value E1 is preferably greater than the second modulus of elasticity value E2, and, even more preferably, the first modulus of elasticity value E1 is between 2.5 and 3.5 MPa and the second modulus of elasticity value E2 is between 0.5 and 1.5 MPa. Such values of the first and second moduli of elasticity were calculated in accordance with standard ISO 37:2011 during tensile testing at modulus 100%.

[0050] The first material 7a and the second material 7b are advantageously made of synthetic, artificial or natural polymer rubbers, it also being possible to use polyurethane mixtures and/or EPDM compounds.

[0051] In accordance with one embodiment, the first material 7a has a modulus of elasticity equal to 3.2 MPa and the second material 7b has a modulus of elasticity equal to 0.9 MPa.

[0052] Preferably and with reference to FIGS. 1 and 4, the first portion 7 has an annular configuration and can be found in a radially inner region of the solid tire 2 and defines a bead zone T. In addition, the second portion 8 has annular configuration and can be found in an intermediate zone I between the bead zone T and a tread zone B of the solid tire 2, the bead zone T, the intermediate zone I, and the tread zone B being contiguous in pairs and respectively being radially arranged from closest to furthest away with respect to the central hole 3.

[0053] With reference to FIGS. 1 and 4, the maximum diameter D3 and the minimum diameter D0 of the solid tire 2 can be seen, and it is clear that the first portion 7 is preferably between the minimum diameter D0 and a first diameter D of the solid tire 2 and that the second portion 8 is between a second diameter D2 and the maximum diameter D3. FIG. 1 also illustrates the first radius R1, the second radius R2 and the maximum radius R3 that correspond, respectively, to the first diameter D1, the second diameter D2 and the maximum diameter D3.

[0054] The hub 4 is advantageously fitted inside the central hole 3 onto the first portion 7 of the solid tire 2.

[0055] With reference to FIGS. 1 and 2, the aforementioned hub 4 preferably has a disc shape characterized by a hub diameter D4 and is made in a single piece or two parts that can be rigidly connected by engaging elements such as screws, nails, adhesives, etc.

[0056] By way of non-restrictive example of one embodiment, the minimum diameter D0 is equal to 132 mm, the hub diameter D4 is equal to 150 mm, the first diameter D1 is equal to 175 mm, the second diameter D2 is equal to 200 mm, and the maximum diameter D3 is equal to 300 mm.

[0057] As shown in FIGS. 3 and 5, the hub 4 preferably comprises circular protrusions 12 which protrude towards the inside of the hub 4 in a direction substantially parallel to the axis of rotation X, and the first portion 7 comprises circumferential grooves 11, formed in walls perpendicular to the axis of rotation X, so as to engage by way of an interference fit with the protrusions 12 and thus increase the reciprocal constraint between the hub 4 and the solid tire 2.

[0058] The seed press wheel 1 preferably comprises a third portion 9 of an annular configuration and made of a third material 7c having a third modulus of elasticity value E3 between the first modulus of elasticity value E1 and the second modulus of elasticity value E2.

[0059] With reference to FIG. 4, the third portion 9 is preferably between the first diameter D1 and the second diameter D2 of the solid tire 2.

[0060] In accordance with an embodiment shown in FIGS. 2, 3 and 5, the intermediate zone I has a tapered configuration so as to converge away from the bead zone T and is made of the second material 7b or the third material 7c. This preferably implies that the intermediate zone I is made of a material having a third modulus of elasticity value E3 greater than the first modulus of elasticity value E1.

[0061] In this way, the ability of the solid tire 2 to enter and adapt optimally to the furrow produced in the ground, which generally has a V shape, is also improved.

[0062] Advantageously and with reference to FIG. 2, the intermediate zone I has a tapered configuration and comprises shoulders 10, comprising connection surfaces between the intermediate zone I and the tread zone B, and the angle formed between the shoulders 10 preferably is equal to 22.

[0063] In accordance with one embodiment, the intermediate zone I and/or the bead zone T comprise lateral surfaces 13, preferably perpendicular to the axis of rotation X, the zones having a thickness, measured in a direction parallel to the axis of rotation X, referred to as the maximum thickness S1.

[0064] In accordance with one embodiment, the tread zone B comprises a tread surface 14, substantially parallel to the axis of rotation X, positioned in line with the maximum diameter D3 and intended to enter into contact with the ground of the furrow during use, having a thickness measured in a direction parallel to the axis of rotation X referred to as the tread thickness S3.

[0065] By way of non-restrictive example of an embodiment, the maximum thickness S1 is equal to 28 mm and the tread thickness S3 is equal to 13 mm.

[0066] The tapered configuration comprising shoulders 10 that connect the lateral surfaces 13 to the tread surface 14 advantageously maintains a substantially uniform inclination of the connection surfaces.

[0067] The first material 7a preferably has a hardness between 60 and 80 Shore A and the second material 7b preferably has a hardness between 35 and 50 Shore A.

[0068] In accordance with one embodiment, the solid tire 2 is in the shape of a disc and has a dimensional ratio R between its maximum diameter D3 and its maximum thickness S1 of between 5 and 15.

[0069] With reference to the exemplary embodiment described above, the maximum diameter D3 is equal to 300 mm and the maximum thickness S1 is equal to 28 mm, meaning that R is equal to 10.71.

[0070] One embodiment of the present invention is directed to a seeder comprising the seed press wheel 1. The seed press wheel 1 includes the solid tire 2 in the shape of a disc that has the central hole 3. The solid tire 2 has the first portion 7, which is made of the first material 7a having the first modulus of elasticity value E1, and the second portion 8, which is made of the second material 7b having the second modulus of elasticity value E2, the first modulus of elasticity value E1 being different from the second modulus of elasticity value E2.

[0071] The steps for producing the seed press wheel 1 intended for a seeder that define the production method are described below.

[0072] A user provides a mold for forming the solid tire 2 included in the seed press wheel 1.

[0073] Depending on the production method used (e.g., injection molding, casting, thermoforming, etc.) and depending on the physical characteristics of the materials used (e.g., melting point, softening point, glass transition temperature, viscosity, density, etc.), the materials deemed most suitable can be used for the molds (e.g., molds made of steel, aluminum alloys, etc.), these being known to a person skilled in the art.

[0074] The user then injects or pours the first material 7a into the mold so as to form the first portion 7 of the solid tire 2 having the first modulus of elasticity value E1.

[0075] This first material 7a is preferably a rubber having the first modulus of elasticity value E1 between 2.5 and 3.5 MPa.

[0076] In accordance with one embodiment, the user injects or pours the second material 7b into the stamp so as to form the second portion 8 of the solid tire 2 having the second modulus of elasticity value E2 that is different from the first modulus of elasticity value E1.

[0077] This second material 7b is preferably a rubber having the second modulus of elasticity value E2 between 0.5 and 1.5 MPa.

[0078] The relative phases of injection or pouring of the first and second materials can be performed advantageously at the same time, and therefore using a bi injection system, or at two separate moments, and therefore using a successive injection system.

[0079] In accordance with one embodiment, the user finishes forming the solid tire 2 and extracts it from the mold so as to be able to use it directly, without the need to remove cores such as those required for the production of hollow tires.

[0080] In accordance with an embodiment of the aforementioned method, the third material 7c having the third modulus of elasticity value E3 is injected or poured into the mold before or after the injection or pouring of the aforementioned second material 7b.

[0081] This third modulus of elasticity value E3 is advantageously between the first modulus of elasticity value E1 and the second modulus of elasticity value E2.

[0082] The first portion 7 preferably has an annular configuration and can be found in the bead zone T of the solid tire 2, and the second portion 8 preferably has an annular configuration and defines the intermediate zone I between the bead zone T and the tread zone B of the solid tire 2, the bead zone T, the intermediate zone I and the tread zone B being contiguous in pairs and respectively being radially arranged from closest to furthest away with respect to the central hole 3.

[0083] In accordance with one embodiment of the aforementioned method, the intermediate zone I has a tapered configuration so as to converge away from the bead zone T and is made of, or of a material similar to, the second material 7b or the third material 7c.

[0084] Although illustrated and described above with reference to certain specific embodiments, the present disclosure is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the disclosure. It is expressly intended, for example, that all ranges broadly recited in this document include within their scope all narrower ranges which fall within the broader ranges.