NZ539716A

NZ539716A - Precision disc tiller and safety device therefor

Info

Publication number: NZ539716A
Application number: NZ539716A
Authority: NZ
Inventors: Michel Evin
Original assignee: Michel Evin
Priority date: 2002-10-14
Filing date: 2003-10-13
Publication date: 2006-11-30
Also published as: FR2845560B1; JP4828123B2; AU2003288315A1; JP2006502725A; PL376370A1; EA200500460A1; WO2004034768A1; FR2845560A1; ES2291719T3; EP1551213A1; KR101083875B1; OA12944A; AU2003288315B2; BR0315294A; RS20050295A; CA2501338C; UA81263C2; CN100397969C; LT2005036A; KR20050074482A

Abstract

The invention concerns a precision disc tiller (1) comprising a frame (2) equipped with at least one gang of non-motorized rotary discs (3) mounted respectively independent and oscillating relative to the support frame (2) via a safety device (5). Said disc tiller is characterized in that each disc (3) is linked to the frame (2) by a coil spring (6) forming at least one and a half turns, one end (6A) of the spring (6) being linkable to the frame (2) while the other end (6B) of the spring (6) is linkable to the hub (8) of the disc (3), said spring (6) being oriented such that the turn(s) of said spring are tightened by winding when the pressure exerted on the disc (3) is higher than the predetermined pressure allowing the disc to be vertically cleared (3) by being lifted.

Description

<div class="application article clearfix" id="description"> WO 2004/034768 - 1 - 539716 PCT/FR2003/003009 PRECISION DISC TILLER AND SAFETY DEVICE THEREFOR The present invention relates to a precision disk tiller of the type comprising a mounted or trailed 5 chassis equipped with agricultural implements consisting of at least one gang of non-motorized rotary tilling disks, these disks working in the ground to a depth that can be adjusted preferably via at least one reference member such as a shoe, wheel or roller 10 coupled to said chassis and being mounted respectively independent and oscillating with respect to the supporting chassis, via a safety device so as, when the pressure exerted on the disk exceeds a predetermined pressure, to allow the disk to move clear vertically 15 and, below said pressure, to allow the disk to return to the work position, and to a safety device for a disk tiller of the aforementioned type. Disk tillers are nowadays well known to those skilled 20 in this art. These disk tillers generally consist of a chassis supporting one or more gangs of disks. Each disk or group of disks may be coupled to the chassis in essentially two ways. The first way is to mount the disks fixedly on the chassis. These disks may, however, 25 be coupled to the chassis in such a way that they can pivot about a vertical axis allowing the disks to be orientated with respect -to the line of forward travel of the chassis. Such is the case in particular of the disks described in patents US-A-2 659 291 and 30 US-A-2 768 864. However, the absence of any possibility of the disks moving clear gives rise to several disadvantages, mainly in particular an absence of precision in the work performed by the disk tiller on account of the fact that, when a disk encounters an 35 obstacle, this results in a partial raising of the chassis so that some of the other disks are no longer able to work. At the same time, the failure of a disk 10 - 2 - to move clear when it encounters an obstacle may lead to premature wear of this disk, or even to breakage of the disk. As a result, rigid mounting of the disk with respect to the supporting chassis does not allow the production of a precision disk tiller able to work to given depths and at high speeds which means that such a disk tiller is also incapable of comprising seeding elements as have begun to appear recently on this type of machine. To solve these problems, disk tillers of the type comprising a mounted or trailed chassis equipped with agricultural implements consisting of at least one gang of non-motorized rotary tilling disks, each tilling 15 disk being mounted independently and oscillating with respect to the supporting chassis of the disk tiller so that they yield under an adjustable predetermined pressure have recently appeared on the market, particularly through French patent application 20 FR-A-2 813 749. In this prior patent application, each tilling disk is connected to the chassis via a connecting member, such as an arm, pivot-mounted on said chassis about an axis roughly parallel to the axis of rotation of the tilling disk, said arm collaborating 25 with a preloading element so as to allow the arm to pivot in the direction of retraction of the disk by raising only when the pressure exerted on the disk exceeds the rated pressure of the preloading element. Return to the work position takes place automatically 30 under the twofold effect of the reaction of the preloading element and of the weight of the disk. Such a solution makes it possible, if one of the disks encounters an obstacle that has to be overcome, to avoid the entire disk-bearing chassis lifting. This 35 results in improved working of the ground and in a constant depth. However, since such machines are equipped with a great many disks, the complexity of the device entailing both the presence of a rigid arm and the presence of a preloading element makes the machine 10 - 3 - complicated and expensive. Furthermore, the large number of disks leads to an extremely short distance between disks. It is therefore necessary to have an extremely short connecting pin connecting the disk-bearing arm to the support piece. This may result in rapid and premature wear, of such devices. Furthermore, as the disks have a tendency to exert a sideways force in the ground, this sideways force tends to increase the wear. Known from another source, through patents US-A-3 640 348 and US-A-2 750 861, are agricultural implements comprising a disk coupled to the bearing chassis of said implement via a spring. In the case of 15 patent US-A-2 750 861, the disk is an opening disk of a seeder intended to open up a furrow. This disk is equipped with a U-shaped yoke, this U-shaped yoke being coupled to the supporting chassis via a leaf spring. This spring, because it is a leaf spring, means that a 20 U-shaped yoke has to be produced in order to avoid any lateral oscillation of ^the disk. This then results, because of the presence of this yoke, in a solution that is unwieldy and expensive. Conversely, the presence of this yoke prevents any sideways clearance 25 or escapement of the disk should it encounter an obstacle. In the case of patent US-A-3 640 348, which applies more particularly to implements of the "covercrop" type where all the disks are mounted on the same support beam, each disk is connected to the 3 0 support beam via an S-shaped leaf spring. Once again, either no element is provided for guiding the disk, and this disk is found to be in constant sideways oscillation, or the lateral integrity of this disk has to be enhanced by an appropriate holding piece, with 35 the risk of increasing both the weight and the cost of such a setup. Finally, there is known, from quite another field of application, through patent FR-A-2 658 979, the - 4 - combination of a disk intended to perform an operation of marking out on the ground, and a spiral-wound spring in the shape of a question mark. The production of a spiral-wound spring does not avoid the sideways 5 wobbling of the disk. One object of the present invention is therefore to propose a precision disk tiller in which the disks are connected to the supporting chassis via a device that 10 allows independent and oscillating mounting of the disks with respect to the supporting chassis while at the same time making it possible to reduce the wear on the connecting pieces of such a device and to simplify the design of such a device. 15 Another object of the invention is to propose a precision disk tiller in which the design of the safety devices allows a greater number of disks to be fitted for the same overall width of machine, because of the 20 small amount of space occupied by such devices. Another object of the invention is to propose a precision disk tiller in which the design of the safety devices allows the disks to escape by moving clear 25 vertically or by moving clear sideways such that the safety device can be considered as capable of working in three dimensions. Another object of the invention is to propose a 30 precision disk tiller in which the design of the safety devices makes it possible, because of the asymmetric nature of these devices, to perfectly meet the requirements of tilling disks which have at least one angle of opening and generally an angle of penetration 35 and which are thus, for these reasons, subject to asymmetric lateral stresses that are perfectly controlled through the asymmetric nature of the safety devices. 40 The above objects of the invention to be read with the alternative object of to at least provide a useful choice. [intellectual property office of ciz - 7 DEC 2005 R E C FI v F n 5 To this end, the subject of the invention is a precision disk tiller of the type comprising a mounted or trailed chassis equipped with agricultural implements consisting of at least one gang of non-5 motorized rotary tilling disks, these disks each having at least one angle of opening and being mounted respectively independent and oscillating with respect to the supporting chassis via a safety device that, when the pressure exerted on the disk exceeds a 10 predetermined pressure, allows the disk to move clear vertically and, below said pressure, allows the disk to return to the work position, wherein each disk is connected to the chassis by a helical spring forming at least one turn, so as to create, in the region of the 15 spring, an area of overlap, one end of the spring being couplable directly or via a connecting piece to the chassis while the other end of the spring can be coupled to the hub of the disk, this spring being oriented in such a way that the turn or turns of said 20 spring tighten by winding when the pressure exerted on the disk exceeds the predetermined pressure, thereby allowing the disk to move clear vertically by lifting. By virtue of the design of the safety device which is 25 formed of a simple helical spring, the disk can move in all three dimensions. This then gives the disk the possibility of escaping from an obstacle by moving clear vertically and/or sideways. Furthermore, it becomes easy, by altering the cross section of the 30 elements used to form the turns of the spring and/or the number of turns and/or the nature of the material of which the elements are made, to define precisely the reactions of the spring so as to avoid the unwanted tapping-together of the disks and limit the sideways 35 movement the disks are allowed. The same advantages as those obtained with a pivoting arm equipped with a preloading element are thus obtained using a part of extremely simple design and the wear of which can office of n£ "■ 1 ALi3 2006 3* £C£f V£a - 6 - limited and reduced over time because of the omission of any articulating component of the pivot pin type. According to one preferred embodiment of the invention, 5 each tilling disk has at least one angle of opening and preferably an angle of penetration causing generally oblique lateral stresses to be exerted on the disk as the chassis moves along, and in that the flanks of the turn or turns of the helical spring are arranged with 10 respect to the disk such that they tend to move closer together under the action of this lateral stress so as to limit the action of this lateral stress. In other words, the lateral stress exerted by the disk tends to cause the turn or turns to wind up, tightening the turn 15 or turns until they jam. Another subject of the invention is a safety device for a disk tiller of the type comprising a mounted or trailed chassis equipped with agricultural implements 20 consisting of at least one gang of non-motorized rotary tilling disks, these disks working in the ground to a depth that can be adjusted preferably via at least one reference member such as a shoe, wheel or roller coupled to said chassis and being mounted respectively 25 independent and oscillating with respect to the supporting chassis, it being possible for this device to be inserted between the chassis and a disk so as, when the pressure exerted on the disk exceeds a predetermined pressure, to allow the disk to move clear 30 vertically and, below said pressure, to allow the disk to return to the work position, characterized in that it consists of a helical spring formed of at least one turn and a half, this spring having a first end couplable directly or via a connecting piece to the 35 chassis and a second end which can be coupled to the hub of the disk, this spring being, when the device is fitted, directed in such a way that the turn or turns of said spring tighten by winding when the pressure exerted on the disk exceeds the predetermined pressure, - 7 - thereby allowing the tool to move clear vertically by lifting. The invention will be clearly understood from reading the following description of exemplary embodiments, 5 with reference to the attached drawings in which: figure 1 depicts a partially perspective view from above of a disk tiller according to the invention; figure 2 depicts a 3/4 rear view of a safety device extending between the supporting chassis and a 10 disk; figure 3 depicts a front view of the safety device of figure 2, and figure 4 depicts a side view of the safety device of figure 2. 15 As mentioned hereinabove, the precision disk tiller that is the subject of the invention comprises a mounted or trailed chassis 2, equipped with agricultural implements 3. The chassis 2 may adopt a 20 great many shapes. In the example depicted, this chassis 2 consists of a frame formed of two longitudinal members connected together by crossmembers consisting of beams equipped with agricultural implements. These beams run roughly at right angles to 25 the draft line of the chassis 2. This chassis 2 is also equipped with a device for hitching to a towing vehicle. The hitch will preferably be of the three point type. The agricultural implements consist of at least one gang of non-motorized rotary tilling disks 3. 30 This gang of disks 3 runs along a working width, that is to say along a line perpendicular to the draft line of the chassis 2. It should be noted that a non-motorized tilling disk is understood to mean tilling disks whose rotational drive is brought about under the 35 effect of the force of friction with the ground, which force is generated by the movement of the trailed chassis. These disks 3 work in the ground to a depth that can be adjusted by way of at least one reference member 4 such as a shoe, wheel or roller coupled to the - 8 - chassis 2. As a preference, this reference member 4 is common to at least three tilling disks 3, preferably at least five tilling disks 3, to guarantee suitable depth adjustment. In the examples depicted, the depth 5 adjusting member 4 consists of a cage roller common to all the tilling disks of the rear gang of the disk tiller. This cage roller 4 is coupled to the chassis 2 via two arms extending behind the frame forming the chassis, said arms being adjustable in terms of 10 position on the chassis 2. This adjustment of the depth is performed by collaboration of this reference member with the hitching device. This adjustment could, similarly, also be performed by the hitching device itself. 15 The agricultural tools that consist of the non-motorized rotary tilling disks 3 are produced in such a way that each tilling disk 3 is mounted independent and oscillating with respect to the supporting chassis 2 of 20 the disk tiller so that it retracts under an adjustable predetermined pressure and thus gives the tilling disks 3 a constant soil-working depth. Each disk 3 is thus connected to the chassis 2 by a helical spring 6 forming at least one turn, preferably at least one and 25 a half turns. One end 6A of the spring 6 is couplable directly or via a connecting piece 7 to the chassis 2 while the other end 6B of the spring 6 can be coupled directly or via a connecting piece to the hub 8 of the disk 3. This spring 6 is directed in such a way that 30 the turn or turns of the spring tighten by winding when the pressure exerted on the disk 3 exceeds the predetermined pressure, allowing the disk 3 to move clear vertically by lifting. 35 In the examples depicted, each tilling disk 3 is a concave disk, preferably of large diameter. Indeed the diameter is generally greater than 48 cm and preferably at least equal to 51 cm. The end 6B of the spring 6 that is coupled to the hub 8 is arranged on the concave 10 - 9 - side of the disk 3. This arrangement has a certain number of advantages. It first of all makes it possible to reduce the space occupied by the spring/disk entity so as to increase the number of disks on one and the same disk tiller without altering the overall width of the entity. It also makes it possible to have a pressure point for the spring 6 running plumb with the point at which the disk enters the ground. This results in better working of the ground. In consequence, this end 6B of the spring is coupled to the part of the hub 8 extending on the concave side of the disk 3 and is positioned near the concave face of the disk 3, that is to say on the opposite side to the 15 free end of said hub 8. This hub 8 is generally coupled at this end to an endplate mounted to rotate freely with respect to said hub 8, the concave face of the disk 3 being bolted to this endplate. This arrangement also makes it possible, using the disk, to protect the 20 hub. Each tilling disk 3 generally has a positive angle of penetration in the range [3 - 20] degrees, and a positive angle of opening in the range [10 - 30] degrees. Each tilling disk 3 is also preferably cut away at its periphery. The cutaways are depicted as 9 25 in the figures. Because each tilling disk 3 has, in order to perform its tilling function, at least one angle of opening and preferably an angle of penetration, this results, associated with the presence of these angles, in generally oblique lateral stresses 30 R being exerted which tierid, as the disk moves along through the ground, to try to return this disk to an upright in-line configuration. In order to limit the effect of these lateral stresses and in particular prevent excessive sideways movement of the disk, the 35 turn or turns of the helical spring are arranged with respect to the disk and wound in a direction in which the flanks of the turn or turns move closer together (direction D in figure 5) under the action of this lateral stress R so as to limit the action of this - 10 - lateral stress particularly once the flanks are up against each other. In order to obtain this result, the winding of the spring needs to be of the helical rather than the spiral-wound type, because at least one area 5 of overlap or partial overlap at the region of one turn or between the turns is needed in order to constitute an axial end stop to react against the lateral stresses exerted by the disk. The exertion of these various forces is more particularly visible in figure 5 which 10 schematically depicts the lateral stresses R exerted on the disk and the resultant D at the turns of the spring. It can be seen that the force D exerted runs from that branch of the spring that is connected to the disk toward that branch of the spring that is connected 15 to the chassis that constitutes an endstop. In order to improve this action of the helical spring and its collaboration with the disks, the1flanks of the turn or turns preferably come to rest against one another, including when the spring is in the rest position. 20 Thus, it can be seen that the safety device obtained by means of the helical spring is a safety device of the asymmetric type which corresponds perfectly to the work of the tilling disk which is itself subjected, as it works, to asymmetric forces. Thus, the helical spring 25 collaborates with the disk to resist the lateral stresses to which the disk is subjected as the chassis moves forward while at the same time allowing the disk to move sideways if it encounters an obstacle. 30 In the examples depicted, this disk tiller comprises, considered in the direction of forward travel of the chassis, at least two roughly parallel successive gangs 3A, 3B of tilling disks 3, the tilling disks 3 consisting of concave di'sks having their concave faces 35 reversed from one gang of disks to the next. This results in the need to produce springs which are, for example, left-handed in the case of the front gang of disks and right-handed in the case of the rear gang of disks. The end 6A of the spring 6 securable to the - 11 - chassis 2 is generally coupled to a mounting plate 7 clamped to a transverse beam of the chassis as illustrated by figures 2 and 3 in particular. This clamping is achieved for example using a screw and a 5 mounting plate running parallel to the mounting plate 7 bearing the end 6A of the spring. The other end 6B of the spring 6 for its part is generally welded to the hub 8 of the disk 3. Other methods of fixing may be envisaged. Thus, the end 6A of the spring 6 may be held 10 in a sleeve, itself fixed to the chassis 2. Each spring 6 comprises from one and a half turns to five turns, said turns being arranged side by side so as to form an alignment of turns along a line 15 transversal to the chassis 2. This arrangement of the turns also allows the lateral rigidity of this setup to be adjusted as desired. The end turn of each spring 6 is continued to form the start of a tangential branch, this branch 6C extending as far as the hub 8 of the 2 0 disk 3 in an arc of a circle with its concave face facing the ground as illustrated in particular in figures 2 and 4. This curving of the branch 6C makes it possible to prevent debris from becoming wedged between the branch 6C and the disk 3. What actually happens is 25 that, because of this special shape of the branch 6C of the spring 6 and because of the angles, particularly the angle of penetration and the angle of opening, of the disk 3, there is a maximum separation between the disk 3 and the branch 6C at this point, hence reducing 30 the risk of the space between the branch 6C and the concave face of the disk 3 becoming blocked or clogged. In the examples depicted, each turn of the spring 6 is formed by winding a wire of square cross section, 35 although this wire could be of any shape of cross section. This spring 6 is preferably formed by deforming a wire with a cross section in the range [650 mm2 - 2600 mm2] for a disk diameter in the range [480 mm - 700 mm]. - 12 - Thus, the disk tiller described hereinabove has as many-safety devices consisting of said springs as it has disks. The design of this safety device, which is 5 greatly simplified by comparison with the safety device of the prior art, makes it possible to obtain a machine of simple design, of low wear, which performs precision tilling, that is to say tilled at a more or less constant depth and at particularly high speeds of the 10 order of 10 to 30 km/hour. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising" and the like, are to be 15 construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including but not limited to". intellectual property qfrce of N.Z - 7 DEC 2005 B £ C EI m g D - 13 - </div>

Claims

<div class="application article clearfix printTableText" id="claims"> CLAIMS

1. A precision disk tiller of the type comprising a mounted or trailed chassis equipped with agricultural implements consisting of at least one gang of non-motorized rotary tilling disks, these disks each having at least one angle of opening and being respectively mounted independently and oscillating with respect to the supporting chassis via a safety device that, when the pressure exerted on the disk exceeds a predetermined pressure, allows the disk to move clear vertically and, below said pressure, allows the disk to return to the work position, wherein each tilling disk is a concave disk connected to the chassis by a helical spring forming at least one turn, so as to create, in the region of the spring, an area of overlap, one end of the spring being couplable directly or via a connecting piece to the chassis while the other end of the spring can be coupled to the hub of the disk, and is arranged on the concave side of the disk, this spring being oriented in such a way that the turn or turns of said spring tighten by winding when the pressure exerted on the disk exceeds the predetermined pressure, thereby allowing the disk to move clear vertically by lifting.

2. The disk tiller as claimed in claim 1, wherein it comprises, considered in the direction of forward travel of the chassis, at least two roughly parallel successive gangs of tilling disks, the tilling disks consisting of concave disks having their concave faces reversed from one gang of disks to the next.

3. The disk tiller as claimed in either of claims 1 and 2, wherein each tilling disk has at least one angle of iNTELLECTUAL PROPERTY OFFICE OF N.Z. ~ 1 Al/J 2006 sefieiurn 04-01-2005 - 14 - FR0303009 opening and preferably an angle of penetration causing generally oblique lateral stresses to be exerted on the disk as the'chassis moves along, and in that the flanks of the turn or turns of the helical spring are arranged with respect to the disk such that they tend to move closer together under the action of this lateral stress so as to limit the action of this lateral stress.

4. The disk tiller as claimed in any one of claim 1 to 3, wherein the end of the spring securable to the chassis is coupled to a mounting plate clamped to a transverse beam of the chassis.

5. The disk tiller as claimed in any one of claim 1 to 4, wherein each spring comprises from one turn and a half to five turns, said turns being arranged side by side so as to form an alignment of turns along a line transversal to the chassis.

6. The disk tiller as claimed in claim 5, wherein the flanks of the turn or turns of each spring rest against one another.

7. The disk tiller as claimed in any one of claim 1 to 6, wherein the end turn of each spring is continued to form the start of a tangential branch, this branch extending as far as the hub of the disk in an arc of a circle with its concave face facing the ground.

8. The disk tiller as claimed in any one of claim 1 to 7, wherein each turn of the spring is formed by winding a wire of square cross section. 'MJItUtu I UAL PROPERTY OFFICE AMENDED SHEET OF iM.z - 7 DEC 2005 RECPh/cn - 15 -

9. A precision disk tiller substantially as herein described with reference to the accompanying figures.

10. A safety device for a disk tiller substantially as herein described with reference to the accompanying figures. </div>