GB2105962A - Spreading boom for a distributor for fertilizer or other material - Google Patents

Abstract

A fertilizer distributor or the like has a wheel-supported frame on either side of which a spreading boom is fastened. Each spreading boom supports spreading nozzles and associated supply tubes and comprises three sections which are retractable and extendable with respect to one another. By making the three sections as parts in a link arm system, extension and retraction of the boom can be brought about automatically by a single hydraulic cylinder 25. <IMAGE>

Description

SPECIFICATION Spreading boom for a distributor for fertilizer or other material This invention relates to a spreading boom for a distributor for fertilizer or other material, the distributor comprising a wheel-supported frame to which the spreading boom is fastened, the spreading boom supporting spreading nozzles and associated tubes and comprising at least three sections, which are foldable to a retracted and an extended position, respectively,two adjacent sections being pivotally connected.

Such machines usually comprise a hopper, which is fastened to the frame and from which the material to be spread is transported by pneumatic means through the tubes of the several nozzles. The nozzles are usually placed on two booms which with respect to the direction of movement of the machine are symmetrically arranged and which when during a spreading operation project horizontally so that the working width of the distributor machine is about 10-15 metres or even more. During transportation these booms may be folded together so that they are instead positioned vertically or obliquely forwards, which means a transportation width which is slightly greater than the width of the track of the spreader.

Spreading booms in previously known machines are of various designs. Thus, there are machines in which the boom is divided at the middle which, however, results in a considerable transportation height of the machine, making transportation difficult on roads where bushes and trees extend over the road. There are also machines with three or more sections. When the boom is divided into three sections it has been possible to fold the outer section manually rearwards so that the height of the machine will be less when the booms are in the transportation position. This has proved to work well but requires manual operations.

An object of this invention is to provide a distributor machine, which is of limited height and in which the spreading booms can be automatically, by means of a single power generating means, brought to a retracted or extended position.

According to this invention there is provided a spreading boom for a distributor for fertilizer or other material comprising a frame to which the spreading boom is connected, the boom supporting spreading means and comprising at least three sections which are foldable to retracted and extended positions, respectively, two adjacent sections being pivotally connected, wherein the axes, about which the sections are movable, are parallel to the direction of movement of the spreader, so that the sections are turned mainly in a vertical plane, power generating means being connected to one of the sections and turning movement of the said one section via transmission means causing a corresponding turning movement of the other sections.

An embodiment of the invention will now be described by way of example with reference to the drawings, in which: Fig. lisa side view of a distributor; Fig. 2 is a rear view; Fig. 3 shows in vertical projection the boom in a transportation position without associated tubes and nozzles; Fig. 4 shows in a like view the boom in a partly extended position; Fig. 5 shows the boom in its fully extended position; and Fig. 6 is a horizontal projection of a complete device according to Fig. 5.

The machine shown in Figs. 1 and 2 comprises a frame 10 supported by wheels 11 and having a hopper 12 for granular material for example a fertilizer which is to be spread over a wide surface.

The machine has a fan 13 which creates a stream of air in tubes 14 (Fig. 6), which lead to the several spreading nozzles 15. By means of an adjustable feeding device (not shown) the material is fed from the hopper down into the different tubes and is transported to the nozzles by means of the air stream in the tubes. Via the nozzles the material is then spread over the surface in question. The rear part of the frame supports two spreading booms 16, which are symmetrical to the centre line of the machine.

Each boom 16 comprises an inner section 17, a middle section 18 and an outer section 19.

The inner section 17 is shaped as a parallelogram (Fig. 6,) having four bars 20 interconnected by an inner beam 21 and an outer beam 22. The inner beam 21 is rigidly secured to link arms 23, which are swingable about a shaft 24 by means of a double acting cylinder 25, the cylinder part of which is pivotally connected to the frame 10 at a point 26, whereas the piston is pivotally connected at a point 27 between two of the link arms 23. The outer beam 22 has projecting lugs 28,29 and 30, respectively, which all are pivot points for elements formed as link arms in the middle section 18.

The middle section 18 also has an inner beam 31 and an outer beam 32, rigidly secured to each other by two bars 33. The bars 33 are, in the extended position of the boom, a direct horizontal continuation of two of the bars 20 of the inner section 17. The inner beam 31 of the middle section has downwardly projecting lugs 34, pivotally connected to corresponding lugs 29 of the inner section 17. The outer beam 32 of the middle section is at its middle part provided with two brackets 35, between which a tension rod 36 is pivotally supported. The tension rod 36 is pivotally connected by a link arm 37 to the lug 30 of the inner section 17.Further, the inner part of the tension rod 36, which in the extended position of the boom is situated above the inner section 17, is connected to the frame 10 at a point 40 by a chain 38 and a sleeve 39 which is variable in length (Figs. 4 and 5).

The middle section 18 also has a push rod 41, the length of which can be changed by an adjustment device 42. One end of the push rod 41 is pivotally connected to the lug 28, and the other end at point 43, is pivotally connected to two links 44,45. The link 44 is pivotally connected at point 46 to the outer beam 32 in the middle section 18, and the link 45 is pivotally connected to a supporting means 47 for the outer section 19. The supporting means 47 is pivotally mounted on supports 48 on the outer beam 32 in the middle section 18.

One end of the supporting means 47 is a bearing point for a beam 49, which can be turned about a shaft 50 which is vertical when the boom is extended and is an outer part of the outer section 19. From the beam a bar 51 extends sideways outwards and has at its outer front part a bracket 52, to which one part of a wire 53 is fastened. The other end of the wire 53 is connected to an L-shaped tilting arm 54 mounted on a flange 55 of the beam 49. Between the tilting arm 54 and a part 56 connected to the flange 55 is a compression spring 57. The outer part of the tilting arm 54 is bent so that it normally engages a shoulder 58 on the supporting means 47.

At their rear parts all section 17, 18 and 19 support nozzles 15, which by means of the flexible tubes 14 are connected to the hopper 12. In order to make it possible to turn the sections with respect to each other, the tubes 14 are divided in the area between the beams of the different sections, one of the tube ends of the sections being of conical shape so that the tubes engage with each other during the extension movement of the boom.

The device operates as follows.

During transportation the spreading booms are stored as shown in Figs. 1 to 3 with the piston of the cylinder 25 retracted. In this position the three sections 17, 18, and 19 are parallel and directed upwards (Fig. 3). When oil is supplied to the cylinders 25, so that the pistons are urged outwards, each inner section 17 swings outwards about the shaft 24. This section in turn activates the push rod 41 and the bars 33 so as to swing the support means 47 and also the outer section 19 outwards and downwards until the section takes up the position shown in Fig. 5. By means of the tension rod 36 the chain 38 keeps the boom at the correct level above the ground during operation. The boom is retracted in a corresponding manner by activating the cylinder so that the piston is retracted and movement takes place in the opposite direction.

The outer section 19 has a safety release device which operates as follows. If an obstacle is touched, the wire 53 will turn the tilting arm 54 out of engagement with the shoulder 58, whereby the outer section is released. When the machine continues its movement forwards the obstacle turns the section rearwards about the shaft 50, so that the section is freed from the obstacle. The outer section can then be returned manually.

It is also possible to use one or more additional sections to increase the spreading width. These sections could in like manner have link arm arrangements to transmit the folding movement from one section to another.

Claims (10)

1. Spreading boom for a distributor for fertilizer or other material comprising a frame to which the spreading boom is connected, the boom supporting spreading means and comprising at least three sections which are foldable to retracted and extended positions, respectively, two adjacent sections being pivotally connected, wherein the axes, about which the sections are movable, are parallel to the direction of movement of the spreader, so that the sections are turned mainly in a vertical plane, power generating means being connected to one of the sections and turning movement of the said one section via transmission means causing a corresponding turning movement of the other sections.

2. Boom according to claim 1, wherein the power generating means being a hydraulic cylinder.

3. Boom according to claim 2, wherein the cylinder operates between the inner section and the frame.

4. Boom according to any preceding claim, wherein the transmission means is situated in the middle section and comprises two substantially parallel bars which are parts of a link mechanism which, when extending the boom, by the influence of the inner section cause a predetermined movement of the outer section.

5. Boom according to any preceding claim, wherein in the retracted position the sections are substantially parallel and vertical, the inner and middle sections being interconnected at their lower parts.

6. Boom according to claim 4, wherein one of the two bars serves as a tension rod, the other bar serving as a push rod at least during a part of the retraction and extension movement of the sections.

7. Boom according to any preceding claim, wherein the outer part of the middle section is pivotally connected to a bar, which, via a link arm, is pivotally fastened to the inner section, the inner part of the bar being linked to the frame by a chain.

8. Boom according to any preceding claim, wherein the outer section is so shaped that in its extended position it can also be turned backwards about a vertical shaft.

9. Boom according to claim 8, characterized in that the outer section (19) is provided with a sensing means (53) which is placed in front of the section and when touching an obstacle releases a lock (54, 58) so that the outer section can be folded backwards.

10. Spreading boom for a distributor for fertilizer or other material, constructed and arranged substantially as herein described and shown in the drawings.