Locking system for a bilateral v-shaped rake

Abstract

A towed star rake is described with a support trolley (1) equipped with wheels (17) connected to a towing vehicle by means of a drawbar (5) and with two side frames (2, 3, 102, 103) consisting of arms (2, 3) pivotably coupled to the support trolley (1) and connected by opening / closing rods (102, 103) to first hydraulic cylinders (22, 23) provided for opening and closing the arms (2, 3). A set of rake wheels (6) are mounted so as to rotate on each of the arms (2, 3) and a pair of locking pins (14, 15) carried slidingly by guide sleeves (24, 25) can be inserted, upon actuation of springs (20, 21), into the slots (28) of a pair of locking supports (26, 27) fixed to the side frames (2, 3, 102, 103), with the arms (2, 3) in the closed position, locking the arms in that position, and disengage from the slots (28) upon actuation of a hydraulic cylinder (11) when the arms (2, 3) are opened, releasing them for the operation of the rake.

Description

[0001] LOCKING SYSTEM FOR A BILATERAL V-SHAPED RAKE

[0002] Description

[0003] Technical Field

[0004] The present invention relates to an agricultural machine. In particular, the present invention refers to a rake intended for turning and collecting hay, fodder, straw, or other similar agricultural products in one or more rows, known in the jargon as windrows. More specifically, the present invention concerns a bilateral rake, of the so-called V-shaped type, which comprises two elongated lateral elements, generally referred to as arms, which carry a series of so-called rake wheels and which open outwards with respect to the direction of travel, forming a V shape when the machine is in use, and move closer to each other when being transported on the road.

[0005] Description of Prior Art

[0006] As known, in agricultural areas, after cutting and possible drying, grass, hay, fodder, and other products in general, must be collected, and this is normally done by automatic machines.

[0007] To facilitate and speed up the work of collecting and baling the products, they are turned over and accumulated in parallel windrows; this operation is assigned to rakes, which are towed by agricultural vehicles, such as tractors, along parallel paths across the fields.

[0008] As mentioned above, the rake proposed by this invention consists of two arms pivotably coupled to a frame or support trolley equipped with wheels, and the arms are kept side by side and parallel to each other in the non-operating and / or transport position, extending along the direction of travel.

[0009] The two movable arms carry a number of wheels equipped with radial teeth, shaped so as to allow them a certain amount of elastic flexion, and aimed at exerting an elastic pushing action on the hay, so as to form the windrow. To this end, when the rake is in operation, the two arms are open and arranged to form a V shape, so that each set of rake wheels converges along the longitudinal direction of travel towards the central area of the structure, thereby exerting a gathering action on the hay towards this central area. A drawbar is connected to the trolley and extends longitudinally between the two arms until it can be hooked to the tractor at the end opposite to the trolley. The so obtained equipment is towed by the tractor and allows simultaneous operation on two sides, due to the V-shaped side arms that can be widened, usually by means of second actuating means, on command, so as to convey the grass or hay towards the center according to the operator’s intention.

[0010] Lifting mechanisms are also provided to lift the rake wheels off the ground when not in operation and / or during transport.

[0011] The key advantages of this type of rake derive from its simplicity of construction and operation, as it does not require the use of actively moving parts with power transfer from the tractor’s power take-off for the rotation of the rake wheels. The absence of moving parts allows an increase of working speeds as well as a reduction the power required from the tractor.

[0012] The arms are generally opened and closed automatically by hydraulic cylinders acting simultaneously on both arms or by a single cylinder that activates a polygon (usually a triangle or a rhombus) with variable conformation, formed by opening rods connected to the arms of the rake, with an umbrella-like structure.

[0013] The cylinder rods, or the cylinder rod (if a single cylinder is installed), are more or less withdrawn in accordance with the intended opening of the arms, and therefore the desired working width and inclination of the rake arms.

[0014] Therefore, during operation, by opening the two arms carrying the rake wheels, the rake can work on larger surfaces, while during transport, again on command, the two arms close parallel to each other, taking up very little lateral space and significantly reducing the overall dimensions in order to allow normal transit on roads, with the teeth of the rake wheels raised off the ground.

[0015] In this transport position, however, the side arms carrying the rake wheels remain in contact with the ground even during transport.

[0016] Therefore, while it is necessary to ensure that the side arms are locked with respect to the opening that could cause considerable damage, it is nevertheless necessary to allow the arms to oscillate in relation to the frame and the central bar. In this way, though not opening, the side arms will have freedom of movement to follow the unevenness of the ground. Summary of the Invention

[0017] It is the object of the present invention to propose a technical solution that allows the side arms to be locked while leaving them free to oscillate vertically, allowing the structure to adapt to the unevenness and depressions of the ground without causing damage.

[0018] Another object of the invention is to propose a locking device that includes a hydraulically controlled uncoupling and release system, which can therefore be operated automatically.

[0019] A further object of the invention is to propose a locking device that can be operated without the need for an independent hydraulic line, which would have to be added to the one already present for operating the side arm opening system, but which integrates with the latter.

[0020] All this must be achieved by means of a simple technical solution that does not adversely affect production costs and maintenance requirements.

[0021] These and other purposes are achieved and the aforementioned problems and drawbacks are overcome by means of the present invention.

[0022] Description of the Drawings

[0023] Other advantages will be apparent, particularly to those skilled in the art, from reading the detailed description below referring to the preferred embodiment reproduced by way of example in the accompanying drawings, in which:

[0024] - Fig. 1 is a side view of a rake that can be improved by applying the proposed invention, with the arms represented almost aligned with the traction bar that supports them;

[0025] - Fig. 2 is a top view of the rake in Fig. 1 , again with the arms aligned with the traction bar;

[0026] - Fig. 3 is a perspective view of the rake in Fig. 2;

[0027] - Fig. 4 is a view of the device proposed by this invention, in the locked position with the side arms closed, seen from below;

[0028] - Fig. 5 is a detailed view of the device proposed by this invention;

[0029] - Fig. 6 shows another detail of the proposed device, referring to only one side of the rake for greater clarity; - Fig. 7 is a top view of the rake highlighting a structural feature of the proposed device;

[0030] - Fig. 8 shows a possible hydraulic diagram for the operation of the rake, which includes the driving system of the device proposed by this invention.

[0031] Detailed Description

[0032] It should be noted that the drawings are for illustrative purposes only, to facilitate understanding of the invention, and do not constitute any limitation thereof, and that the proportions between the shown parts may not correspond to the actual proportions.

[0033] Substantially, the invention consists of a towed star rake, characterized by a particular supporting structure and independent settings of the position of the raking groups, so as to allow the operator to position them, from time to time, in the best possible way depending, for example, on the width and shape of the windrow to be produced.

[0034] The towed star rake, made according to the example shown here, with reference to the attached figures, has independent settings and parts that operate in combined sequence.

[0035] Going into more detail, the rake comprises a support trolley 1 equipped with wheels 17 designed to support the rear of the rake and to be connected to a towing vehicle, such as an agricultural tractor (not shown), by means of a drawbar 5.

[0036] As can be seen in Figures 1 , 2 and 3, the drawbar 5 originates at the support trolley 1 with an initial section 4 inclined upwards, so as to extend towards the towing vehicle at a higher level than the rake, so as not to interfere with the latter's operation.

[0037] Two side frames are also pivotably coupled to the support trolley 1 , consisting of two side arms 2, 3, which extend in the same direction as the drawbar 5, and two rods 102, 103 pivoted at intermediate points of the side arms. The pivotable coupling allows the two arms 2, 3 to rotate outwards with respect to the drawbar 5, and the rods 102, 103 connect the two arms to first hydraulic cylinders 22, 23 (Figure 2) aimed at causing the arms 2, 3 to open from a position close to and almost parallel to the drawbar 5 to a maximum V-shaped opening position.

[0038] Then the same first hydraulic cylinders 22, 23 bring the arms 2, 3 back to the closed position, aligned and parallel with the drawbar 5.

[0039] Second hydraulic cylinders 11 , 12 (Figure 6) may then be provided, pivotably coupledto the support trolley 1 and having their rods connected to the respective arms 2, 3 to bring the corresponding ends of the arms 2, 3 close to each other or move them away in order to reduce or increase the distance between the ends, respectively.

[0040] In practice, this action corresponds to reducing or increasing the width of the produced windrow, since it will determine the distance between the first two rake wheels 6 positioned along the arms 2, 3. This feature will not be discussed further, as it is not directly relevant to the invention.

[0041] A series of rake wheels 6 are mounted so as to rotate on each of the arms 2, 3. This description will not discuss the details of the shape and functionality of the rake wheels 6 as they are not relevant to the invention in question.

[0042] In accordance with the invention, the locking device for arms 2, 3 comprises a plate 10 anchored to the bar 5 with a release cylinder 11 fixed thereto in such a way that the cylinder is fixed with respect to the bar 5.

[0043] The rod 12 of the cylinder 11 operates on the central part of a sort of yoke 13, movable along the bar 5 on the side of the plate 10 facing the trolley, the ends of which are connected to two pins 14, 15 which are carried slidingly within two respective sleeves 24, 25 fixed to opposite sides of the plate 10, so that the pins 14, 15 are orthogonal, even if slightly offset laterally, to the axes of rotation 16 of the hinge points around which the respective side arms 2, 3 rotate (axis A in figure 7).

[0044] The central part of the yoke 13 has two tension springs 20, 21 anchored thereto, the opposite ends of the springs are hooked to the side of the plate 10 opposite the side bearing the release cylinder 11 .

[0045] In addition, locking supports 26, 27 in the form of elongated flat brackets (Figure 5) have been applied to the side arms 2, 3, to extend from the plane of the rods 102, 103 of the side arms towards the central bar 5 and in the direction of the ground. Each of the brackets has a slot 28 extending along the direction of their greatest length, i.e., toward the ground, curving inward.

[0046] Advantageously, the extension of the brackets of the locking supports 26, 27 follows the course of the slots 28, so that the brackets are also curved inwards when viewed from the side arms towards the ground.

[0047] When the hydraulic cylinder 11 is extended, due to the elastic return reaction of the springs 20, 21 , the cylinder cannot be controlled in the extension direction, due to the one-way valve 30 (Figure 8), which will be discussed below, that prevents the flow to the extension chamber, the locking pins 14, 15 are passed through these slots 28, thus locking the rods 102, 103 and the side arms 2, 3 in the closed position, and the shape of the slots 28 and the brackets is such as to allow for the free oscillation of the side arms with respect to the central bar 5.

[0048] A support roller 34, 35 is fixed to the plate 10, in an approximately central position and corresponding to each locking support 26, 27, and aimed at constituting a limiting base of the locking support 26, 27 associated with the relative rod 102, 103 of the corresponding side arm 2, 3 during the closing phase. In this way, since the brackets slide on the support rollers 34, 35, it is ensured that the positioning of the side arms with respect to the locking pins 14, 15 is always well defined.

[0049] The outermost shape of the supports (the section corresponding to distance D in figure 5), which delimits the slot 28 from the side of the drawbar 5, has been designed to keep constant the distance between the pin and the support roller, i.e., with increasing width as the inclination of the axis A of the section itself varies. This ensures that, within the tolerance range, the pin 14 will never force into the slot 28, thus avoiding the risk of unwanted disengagement of the system.

[0050] This particular shape serves two purposes, i.e. maintaining a constant distance D between the center of the sliding slot 28 and the corresponding support roller 34 (external shape) and allowing the side arms to move freely, according to the center of rotation 16 of the frames, allowing the locking pin 14 to slide inside the slot 28. This is due to the fact that when opening outwards, the arms 2, 3 also move downwards with respect to the central bar 5. This leads to a curvilinear movement, and the arc shape of the slots allows the pins 14, 15 to remain always centered with respect thereto, until they disengage from the slots 28.

[0051] The supply of fluid to the release cylinder 11 has been inserted into the existing hydraulic system for opening and closing the machine (Figure 8). Two one-way valves 30, 31 have been inserted to ensure that the oil flows only in the desired direction causing the retraction of the rod 12, while still allowing free discharge from the locking cylinder during its various operating phases.

[0052] A bypass 32 has also been provided between the two chambers of cylinder 11 to allow free discharge from the rod side chamber, for example to open the arms 2, 3 or when no command is given.

[0053] To open the side arms for raking, the arms 2, 3 must first be further closed, and during this closure step the oil is pushed into the hydraulic circuit L to activate the arms opening / closing cylinders and compensation cylinders (if present).

[0054] When the pressure rises in the cylinders 22 and 23 on the closing side, the release cylinder 11 also retracts the rod 10, counteracting the elastic reaction of springs 20 and 21 , to move the locking pins 14, 15, tensioning the springs 20, 21 and withdrawing the locking pins 14, 15 from the slots 28.

[0055] Subsequently, taking advantage of the return time of the previously loaded springs 20, 21 , which act on the yoke 13 to return the cylinder 11 (with the oil in the rod side chamber in free discharge) and consequently the pins to their initial position, the arms 2, 3 are caused to open.

[0056] The locking supports 26, 27 thus escape the lock of the locking pins 14, 15 and allow the arms 2, 3 to open.

[0057] Once the raking operation is complete, the pressurized oil is sent to the line L in order to reverse the movements of the driving cylinders 22, 23 of the side arms and compensation arms (if present). The pressure acting in the closing chambers of cylinders 22, 23 also acts on the release cylinder 11 , whose rod retracts, moving the yoke 13 and the locking pins 14, 15 so as to leave space for the locking supports 26, 27 to reposition against the support rollers 34, 35. Once the arms 2, 3 are closed, the elastic return reaction of springs 30, 31 causes the pins 14, 15 to move back, entering the slots 28 and locking the side arms 2, 3 again in a position parallel to central bar 5 for transport.

[0058] It should be noted that the locking system described herein can also be used if the yoke 13 acting on the locking pins 14, 15 is operated in a different way, for example by means of an electric drive or a mechanical lever, or by means of a pulling element such as a steel cable or a rope (alternative systems not shown here).

[0059] The advantages of the system described herein are obvious.

[0060] Firstly, the described system allows the side arms 2, 3 to be locked against the opening but allows the arms to swing with respect to the central bar 5 due to the double joint, which has degrees of freedom in both the horizontal and vertical planes. In this way, the side arms, although not opening, will be free to move to follow the unevenness of the ground during transport of the machine.

[0061] Therefore, the system locks the side arms transversally but leaves them free vertically.

[0062] In fact, it should be noted that, although locked in the transport position, the side arms 2, 3 remain resting on the ground by means of wheels 29 (figure 2). The relative movement between the central bar 5 and the side arms 2, 3 must be allowed, as the ground oscillations will not be uniform across the entire machine. Considering the double joint connecting each side arm to the opening cylinder, which acts as a hinged rod, this vibration does not cause horizontal translation but rather a rotation; the slot 28 and the outer profile of the locking support 26, 27 are shaped to follow this particular movement.

[0063] Due to the profile of the support 26, 27 and the presence of the support roller 34, 35, it is ensured that the pin 14, 15 is always inside the slot 28. This means that locking is possible even if the machine is not on a flat ground and ensures that, if there is relative oscillation between the central bar 5 and the side arms 2, 3, the pin 14, 15 will never force against the support 26, 27, thus never risking accidental release of the frame.

[0064] The shape of the support 26, 27 and in particular of the slot 28 has the function of adapting to the oscillatory movement of the arm, which is not perfectly straight but rotates, albeit with a very wide radius. It should also be noted that the pins 14, 15 are oriented perpendicular to the axes of rotation of the hinge points around which the respective side arms rotate. This feature is shown in Figure 6 by the dotted line.

[0065] This ensures that the pins 14 and 15 will never force their way inside their respective sliding slots 28. Considering the large masses involved and the relative moments generated, if the device were to be forced due to misalignment, this could result in the unwanted release of the side arm or damage to the locking device.

[0066] Secondly, the described locking and release system is hydraulically controlled, without the need for an additional hydraulic line. The system has in fact been incorporated into the machine's hydraulic opening line.

[0067] When the machine is closed, the release cylinder 11 retracts due to the pressure acting on the actuating cylinders 22, 23 on the closing side, retracting the locking cylinders 14, 15, and at the end of the closing movement, the drop in pressure allows the springs 20, 21 to return, thus locking the system.

[0068] It should be noted that the use of the spring return also ensures safety in the event of pipe breakage or accidental activation of the hydraulic system, also because the side arms always remain locked and the locking pins 14, 15 cannot be released from their slots 28 without operator intervention.

[0069] A fundamental advantage is that no additional hydraulic line is to be added to the tractor other than the one installed for controlling the opening of the arms. This advantage is achieved by the combined and sequential operation implemented by this technical solution, considerably simplifying the construction of the rake and therefore limiting construction costs and maintenance costs while maintaining the simplicity of the operator's control and monitoring actions.

[0070] Furthermore, the particular configuration that characterizes the invention allows the arm opening lock to be kept completely safe when the rake is in the closed position, a feature that is very advantageous during transport, especially on the road.

[0071] It is understood that the above has been described by way of example and is not intended to be limiting. In particular, during the manufacturing phase, single construction details may also be modified, without affecting the logical functionality of the machine itself.

[0072] Therefore, possible modifications and variations of the invention are considered to fall within the scope of the application concerning this technical solution, as described above and claimed below.

Claims

CLAIMS1) A towed star rake comprising:- a support trolley (1) equipped with wheels (17) intended to support the rake at the rear and to be connected to a towing vehicle by means of a drawbar (5);- two side frames (2, 3, 102, 103) consisting of arms (2, 3) articulated to said support trolley (1) with extension in the same direction as said draw bar (5), so as to rotate in the vertical plane and in the horizontal plane with respect to the draw bar, and of opening / closing rods (102, 103) aimed at connecting intermediate points of said arms (2, 3) to first hydraulic cylinders (22, 23) provided to determine the opening and of said arms (2, 3) from a position near and nearly parallel to said drawbar (5) to a position of maximum opening to determine the operational condition of the rake, and vice-versa their closing to return the arms to a non-operating condition;- a set of rake wheels (6) mounted swiveling on each of said arms (2, 3); characterized by comprising a system for locking said arms (2, 3) in the closed position, which includes:- a pair of locking pins (14, 15) carried sliding by means of guide means (24, 25) attached to said drawbar (5) toward one end of said drawbar (5), in the locked condition, and vice versa in the unlocked position;- a pair of locking supports (26, 27) attached respectively to said side frames (2, 3, 102, 103) and featuring each a slot (28) designed to be crossed by a respective locking pin (14, 15) when the locking pin is moved by said driving means toward said locking position; driving means (11 , 12, 13, 20, 21) of said locking pins aimed at moving said locking pins to said locking position, to engage into said slot (28) with said locking supports (26, 27), to lock said side arms (2, 3) in the closed position, and vice-versa to disengage said locking pins (14, 15) from said slots (28) and release the arms (2, 3).

2. A star rake according to claim 1 , wherein said guiding means comprise two sleeves (24, 25) within which said locking pins (14, 15) are slidably carried.

3. A star rake according to claim 1 or 2, wherein said driving means (11 , 12, 13, 20, 21) of said locking pins (14, 15) comprise a release hydraulic cylinder (11) whose rod (12) acts on a yoke (13) having ends respectively fastened to said locking pins (14, 15) and with two tension springs (20, 21), acting in contrast to the action of said hydraulic cylinder (11).

4. A star rake according to any of the preceding claims, wherein each of said one pair of locking supports (26, 27) comprises a flat bracket of elongated shape attached to a rod (102, 103) of the respective side frame and extending from the plane of said rod (102, 103) toward the central rod (5) and in the direction of the ground.

5. A star rake according to claim 4, wherein said locking supports (26, 27) abut against support rollers (34, 35) so as to limit the swing of said side frames and to define the closing position of said side frames.

6. A star rake according to the preceding claim, wherein said locking supports (26, 27) have the section delimiting said slot (28) on the side of the drawbar (5) with the width increasing as the inclination of the axis (A) of said section changes, so as to maintain a constant distance (D) between the respective locking pin (14, 15) and the respective support roller (34, 35) with the side arm (2, 3) in the closed position.

7. A star rake according to any of the preceding claims, wherein said locking pins (14, 15) are oriented orthogonal to the rotation axes (16) of the hinge points around which the respective side arms (2, 3) rotate.

8. A star rake according to any of the preceding claims, wherein said locking system is attached to said drawbar by means of a plate (10) on which said guide means (24, 25) of said locking pins (14, 15) and said driving means (11 , 12, 13, 20, 21) are arranged.

9. A star rake according to claim 1 , wherein a hydraulic circuit is provided comprising a hydraulic line (L) originating from said towing vehicle, a pair of first hydraulic cylinders (22, 23) which constitute actuating means for opening and closing said side frames, wherein said first hydraulic cylinders (22, 23) and said release hydraulic cylinder (11) are connected to said hydraulic line (L), with one-way valves (30, 31) provided for the connection of said release hydraulic cylinder (11) to said hydraulic line (L), so that the activation of saidrelease hydraulic cylinder (11) for the release of said locking pins (14, 15) from said slots (28) is determined by the actuation of said first hydraulic cylinders (22, 23) to close said side arms (2, 3) and that in all other remaining conditions said release hydraulic cylinder (11) is not actuated, thus remaining subject to the return action of said springs (30,31).

10. A star rake according to claim 9, wherein a by-pass circuit discharging in said hydraulic line (L) is provided between the two chambers of said hydraulic release cylinder (11).

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