A three-point linkage system mounted on the rear of a tractor, allowing the spreading of powdered or granular products via a screw boom.

Abstract

The invention relates to a system mounted at three points on the rear of a tractor or other motorized vehicle, enabling the even spreading of powdered or granular products by means of an auger boom. It consists of a storage hopper 1, a metering system 2 and 3, and two tubes 5 and 9 with holes 8 along their lower edge. Two continuous-thread augers 6 rotate within these tubes, drawing the product, which falls by gravity from the center to the ends. To reduce the width for road transport, the tubes 9 are foldable.

Description

The present invention relates to a three-point liftable and height-adjustable gate system at the rear of a tractor or other motorized machine; characterized by the fact that it includes a screw distribution system allowing the spreading of powdery or granular products on the ground in a regular manner and at a low height relative to the wind, regardless of the configuration of the latter and over the entire area swept by the boom. 'Currently, with existing mounted devices, the uniform spreading pattern varies according to the terrain and wind strength; the system according to the invention makes it possible to effectively remedy these disadvantages. It is primarily composed of a rigid tubular frame which, extending from the three points of attachment to the carrier vehicle, supports: a conical hopper, small base down, which can be circular or any other shape, in which the product to be spread is stored. The lower part of this hopper is closed by a horizontal sheet metal panel with two openings, one on the right and the other on the left relative to the transverse axis of the device. To allow for precise metering of the applied product, these two openings can be more or less obstructed by sliding two rigidly connected rails beneath the horizontal sheet metal. The movement of these rails is precisely controlled and synchronized with each other by a screw and nut system so that, depending on the degree of opening, a precise metering of the product falling by gravity is evenly distributed on each side of the device. This assembly is located at the rear of the device and thus allows for precise control of the product quantity over a defined area. On the front face two other rules, these free from each other and whose sliding is controlled by two independent levers accessible directly from the driver's seat of the carrier vehicle; these levers allow either to completely close the openings of the horizontal sheet and thus stop the descent of the product, or to close only one or the other side to reduce the covered area by completely obstructing a hole for the passage of the product. Once released, the product falls by gravity into two horizontal hollow tubes, one on the right and the other on the left, beneath the openings already described. Inside these tubes rotates a continuous-thread worm screw, the direction of which is designed to push the product from the center of the device towards the ends, ensuring its movement along their entire length. These screws are fixed within the tubes by spherical bearings located at each outer end, thus preventing any jamming. Finally, to carry out the spreading: on a lower generatrix of the two tubes, a series of equidistant holes allows the product to pass through which, pushed by the screws, moves towards the ends of the tubes and spreads directly onto the ground along their entire length. To improve spreading regularity, all lower holes through which the product falls can be partially obstructed by a pivoting strip in the transverse direction along a radius; the pivoting can be different at the two ends of these strips, for example a larger opening on the outside of the device: the strip is found to make an angle with respect to the generatrix carrying the holes. A quick-release locking mechanism allows the strips to be secured in the desired position. The flexible design of the strips allows them to accommodate torsional deformations due to this position while remaining firmly pressed against the tubes. The power source for the rotation of the screws is provided by the tractor's power take-off and a cardan shaft transmission to a reduction and angle gearbox with one input and three outputs: two horizontal, one right and the other left for driving the screws, the third vertical one drives an agitator at the bottom of the hopper to avoid the bridging effect of the product in it. For safety, in case a large quantity of product reaches the ends of the tubes, an opening with a cross-section equal to that of the passage is made to prevent damage to the screws. On the other hand, since the spreading width is significant (6 meters minimum), for reasons of space during transport, each right and left tube and their screw are foldable upwards to give an overall width less than the maximum allowed by the Highway Code. A simple and effective locking mechanism keeps them in the folded position: a rounded flat iron cradle with a handle axle The articulation of the end tubes on the central tubes is achieved by double-jointed axles and bearings: one vertical, the other horizontal. If, during operation, the end of a tube encounters an obstacle, the assembly pivots on these joints to protect the tube and its screw, automatically retracting and rising simultaneously. Under its own weight, it returns to its initial position as soon as the obstacle is cleared. Finally, at the right of this articulation, the endless lives being free since the bearings are at the ends: they are centered with respect to each other by a pin in the axis of the inner screw and a bore in the outer screw; the rotational drive is ensured by a lug welded on the inner screw pushing a finger welded on the outer screw. The design of the quarry section of the tubular chassis allows for the attachment of a trailer. The system according to the invention is particularly intended for spreading powdery limestone amendments (powdery slag, slag) and granules or any product having a powdery or granular structure. The attached drawings illustrate the invention: -Figure 1 shows a front cross-sectional view of the system according to the invention and a side view. - Figure 2 shows a top view detail of the base sheet of the hopper and its dosing system. - Figure 3 shows in cross-section the autonomous closing system of each hole on the front side. - Figure 4 shows a cross-section and bottom view of a spreading tube and its sliding strip. - Figure 5 shows a cross-section of the entire spreading ramp with screws, bearings and joints. - Figure 6 shows the detail of the joints of the outer tubes and the drive of the screws. The system shown in Figure 1 comprises a hopper (1) for storing the product to be spread; it is closed at its base, but two openings (2) located to the right and left of the transverse axis allow the product to descend. These openings can be more or less obstructed by rigidly connected rails (3); the degree of opening is controlled by a screw and nut system (4) which synchronizes the opening of the two rails (3) identically on each side: see detail in Figure 2. On the front face of the system according to the invention, two levers (14) separately control two independent rules (15j) allowing the product passage holes to be closed; these rules (15) come to rest on the ends of the rules (3): according to detail figure 3. Two horizontal spreading tubes (5) and (9), each with a passage provided under openings (2) and in which two counter-threaded screws (6) are installed, receive the product which falls by gravity. These screws are fixed in the tubes by spherical bearings (12) at each end, as detailed in Figure 4. By means of a reduction and angle drive (7) driven by an external power source, the screws (6) will drive the product towards the ends of the system. Holes (8) evenly distributed along the entire length of the lower generatrix of the tubes (5) and (9) then allow the product to pass to the ground. To perfect the regularity of the product's fall, it is possible to adjust the opening of the holes (8) by moving a slider (10) along the radius of the tube in the transverse direction to increase or decrease the passage sections. Thanks to their elasticity, these strips allow the central holes to be blocked more extensively than the end holes: see detail figure 4. For safety reasons, in case of accidental jamming at the ends of the two tubes, an opening (13) prevents any destruction of the parts: see detail figure 5. Furthermore, to reduce the width during movement, the tubes (9) are hinged and fold upwards: hinged by two axes, a vertical one (16) fixed to the inner tube and a horizontal axis (lu), an intermediate piece (18) hinged on the two axes allows freedom of movement of the outer tube in the horizontal and vertical planes. At this hinge, the screws, also in two parts, are assembled by internal centering: a pin (19) on the inner screw and a bore (20) in the outer screw; a lug welded to the inner screw drives the outer screw in rotation: see detail in figure 6.

Claims

DEMANDS - 1 - Spreading system, according to claim 1 of main patent 86 ol 063, comprising a hopper for receiving the powdered fertilizer to be spread and two arms located on either side of the hopper, pierced with holes located at their lower part to allow the passage of the fertilizer and an auger for distributing the fertilizer according to the arms; characterized in that the system is connected to the tractor by a lifting device so as to be able to adjust the distance between the holes and the ground and in that the augers are operated by the power take-off of the tractor. - 2 - System according to claim 1 characterized in that the arms are foldable and articulated to reduce the width during movement. - 3 - System according to claim 1 characterized in that the position of the openings (2) at the bottom of the hopper (1) allows the quantity of product to be spread to be distributed in half in each distribution ramp (5) and (9). - 4 - System according to claim 3 characterized in that the tubes (5) are located just below the openings (2) of the feed hopper (1). - 5 Sy - System according to claim 1 characterized in that the holes (8) of the ramps (5) and (9) can be obstructed in an adjustable manner by torsionally deformable strips (10) sliding transversely along a radius so as to obstruct the inner holes more than the outer ones.