GB2229618A - Improvements relating to spreading machines - Google Patents

Abstract

The invention provides a spreading machine comprising a hopper 10 with sloping sides and an auger 21 in the base of the hopper. The auger is provided opposite an opening 30 in a side wall with paddles for sweeping material to be spread from the hopper out of the opening where it is grabbed by a spinner 42 and propelled outwardly over the ground. Each of the said paddles comprises a telescoping strut having a spring to urge the parts of the strut to an outwardly telescoped position. At the outer end of each paddle on one of the parts thereof is a plate which engages the material and forces it both axially and radially. Making the paddles in telescopic arrangement ensures that the outer part of each paddle can deflect rearwards clear of any obstruction in the hopper. <IMAGE>

Description

Improvements Relating to Spreading Machines This invention relates to spreading machines for the spreading of materials, such as manure, slurry, straw, and other materials which are spread in agriculture, such machines being of the type comprising a hopper for receiving the material to be spread, said hopper having side walls which mutually converge in a downwards direction to define at the lower end a gulley in which is located a rotary assembly comprising means defining at least one auger for moving the material axially of the rotary assembly. In one of the side walls is an opening through which the material is discharged in a direction normal to the axis of rotation of the rotary assembly and in the vicinity of the said opening is an impeller which lies with its axis parallel to or substantially parallel to the axis of the rotary assembly.

The impeller is driven at high speed compared to the speed at which the rotary assembly is rotated, so as in fact to grab and fling the material away from the machine in a direction normal to the axis of the rotary assembly.

The machine is for moving over the ground to be treated in a direction which is the direction in which the rotary assembly axis lies, and therefore as the machine is used, the material is thrown laterally of the direction in which the machine moves.

Such machines will be referred to hereinafter as "spreading machines of the type set forth".

Also, in the interests of simplicity of description reference will be made hereinafter only to the spreading of the various forms of agricultural manures which are spread by the machines, but it is to be borne in mind that the machines can spread other materials.

The known spreading machines of the type set forth have only recently (within the last 5 or 6 years) been introduced into the United Kingdom market, and, like all new types of machines, have a number of technical shortcomings. The present invention seeks to improve a technical drawback which has been identified in the existing known spreading machines of the type set forth.

The aforesaid technical drawback resides in that the rotary assembly is provided with a plurality of paddles which radiate from the assembly, and serve to push the material to be spread through the opening in the hopper side. Various designs of paddle have been conceived for example as disclosed in British Patent 2124870, and European Patent Specification 0077000. As regards the paddles disclosed in said British patent, they suffer from the disadvantage that being resilient spring arms, they tend to deflect over the material to be discharged, and effective discharge is not achieved.With the paddles as disclosed in the said European specification, there can be a tendency for the paddles to rotate the material to be discharged rather than to force it through the said opening, although the paddles disclosed in each of the British patent and the European specification do work to a limited degree.

The present invention seeks to provide a further construction of paddle for the effective ejection of the material through the hopper side opening, and in accordance with the present invention a paddle for this purpose comprises relatively movable portions which are urged by spring means to maintain an operative condition, but which under load can be moved relatively in order for example to override an obstruction.

The paddle is preferably in the form of an elongated strut with the said parts being arranged to inters it telescopically, and a compression spring arranged between the parts serves to maintain them biassed towards the operational position. However, should an obstruction be met, or should the material being ejected be of such consistency, the parts can telescopically slide so as to reduce the overall length of the strut, and this feature can be used to deflect an operational face of the paddle away from the material which is engaged by the face.

One part of said telescopically interfitting parts preferably is rigidly secured to the rotor core of the rotary assembly, whilst the other part carries said working plate or face and is telescopically interfitted in the said firstmentioned part.

Adjacent each paddle, the rotary assembly being provided with a plurality of such paddles which are in end elevation of the rotary assembly angularly offset, there is provided a shield structure in the form of a V-shaped plate which protects the telescoping part of the associated paddle, and a guide plate which forms a shielding and guide means for the end plate of the paddle to prevent it from rotating about the axis of the strut.

The invention and the various preferred features of same will be better understood by making reference to the accompanying drawings which show an embodiment of the invention.

In the drawings, of which Figs. 1 to 6 are identical to Figs.

1 to 6 of our co-pending U.K. Patent Application 2173682: Figure 1 is a diagrammatic perspective view of a spreading machine of the type set forth; Figure 2 is a side view of a spreading machine according to the invention the subject of U.K. Patent Application No.

2173682; Figure 3 is a plan of the spreading machine shown in Figure 2; Figure 4 is a sectional view of the hopper of the machine of Figure 2 and 3, the section being on line X - X in Figure 3; Figure 5 is a view similar to Figure 4, except that the section is taken on the line Y - Y of Figure 3; Figure 6 is a side view of an alternative form of auger; Figure 7 is a sectional side view similar to Figure 4, but to an enlarged scale, showing a paddle according to the embodiment of the invention; Figure 8 is a perspective view of the paddle shown in Figure 7; and Figure 9 is a perspective view of the paddle shield shown in Figure 7.

Referring firstly to Figure 1, the apparatus shown is in the form of a trailer having an elongated body 10 at the front end of which is a towing hitch 12, and towards the rear end the vehicle is supported on ground engaging wheels 14, 16.

The trailer is open topped, and has a V-shaped cross-section as shown defined by two mutually inclined walls 18 and 20 leading to a gulley 15, and two end walls 17, 19.

In the gulley of the trailer is a rotary assembly 21 comprising as shown in Figures 2 and 3 an auger shaft 22 having a first auger section 24, a second auger section 26, and a central beater section 28. Auger section 24 extends from the rear end 19 of the vehicle to a position adjacent an edge of an opening or door 30 in side 20 of the hopper, and is provided with conveying flights 23 which are disposed on a helical path of a first hand. The flights may be individual and spaced flights, or continuous flights with various shapes and or steps may be used to define the active portion of the auger. In fact, it appears that a flight with a rough edge like a saw reduces horse power requirement and may therefore be desirable.

Auger section 26 is constructed similarly, its flights being indicated by reference 34, but the helix of auger section 26 is of opposite hand, so that by rotation of the auger shaft 22, material placed in the hopper 10 will be moved from the ends of the vehicle towards the door 30. The drive means for the shaft 22 is contained in the casing 36 which may contain a gear box and a power take-off shaft coupling to enable the rotor to be driven from a tractor behind which the spreader is towed.

Each of the sections 24 and 26 has a base or core shaft portion on which the flights are mounted, and the base portion is of tapering configuration as shown clearly in Figure 2, the shaft portion decreasing in dimension from the adjacent end of the hopper body towards the central section 28. In the example illustrated, the shaft section of each auger section 24, 26 is of hexagonal form. The auger may alternatively be parallel sided.

The centre section 28 comprises a hexagonal shaft portion 28 as shown in Figure 4, and this portion carries beater paddles 40 which beat the material fed by the auger sections into the path of the paddles, and this beating in turn forces the material through the door 30. The material is engaged by a high speed distributor 42 (see Figure 1) made up of a number of angularly spaced bars which are arranged on a distributor shaft, such shaft being rotatable about a horizontal axis 46 which is parallel to the axis of the shaft 22 as shown in Figure 4. The distributor 42 is, through suitable gearing in the casing 36, driven at a speed many times the speed of the auger, and it may be rotated in the direction as shown by arrow 48 in Figure 1 when the machine operates in the overshot mode, or in the opposite direction when the machine operates in the undershot mode.The direction of rotation of the auger is indicated by arrow 50 in Figure 1.

The opening 30 is associated with a sliding door 52 (which may be in two or three sections) which can be displaced by a suitable power means such as a hydraulic ram (or rams) or the like in order to vary the size of the opening 30 depending upon the type of material which is being spread by the trailer.

The opening 30 is designed so as to be capable of discharging the box muck referred to herein, and furthermore the door opening 30 is specifically located so that, as shown in Figure 2, the material 56 in the trailer, by virtue of its repose angle, will tend to repose and gravitate towards the opening 30 and directly out of same, facilitating discharge from the hopper.

The location of the door in relation to the hopper size is important to the invention the subject of said co-pending application and the limiting parameters can be understood by referring to Figure 2. If one considers planes W and X, and Y and Z, extending at angles 250 and 750 to the horizontal from the points A and B, being the points, when viewed in side view, on the respective edges of the opening 30 which lie in the axis 47 of the distributor, then the top corners 59 and 61 of the hopper should like between the planes W and X, and Y and Z as shown.

With this arrangement the majority of the material 56 contained in the hopper is therefore reposing towards the opening 30, thereby lightening the load on the auger, and preventing barreling of the material with the auger, the barreling comprises a situation when the material simply traps between the flights of the auger and is turned with the auger but does not make any axial progression of the auger.

Figures 2 and 4 also illustrate tines 11 for restraining uprising manure in the hopper due to the uprising of the paddles 40, from passing over the edge 13 of the hopper. The tines may be fixed or hinged individually or as an assembly so that they hang down when the hopper is empty for loading, and are pushed upwards into their working position by the uprising material during operation of the machine to prevent material from being pushed over the edge 13.

As stated in said co-pending application, the apparatus includes an adequate door for the discharge of box muck, and the angular range of the planes W:X and Y:Z has been found to be the best range for materials of the type in question, coupled with the use of an auger having sections of opposite hand to feed the material from both ends of the hoppers to the door, providing an efficient apparatus in which the discharge of the box muck is performed effectively.

As shown in Figures 2, 3, and 6, the auger shaft over the respective sections 24 and 26 is of tapering form, tapering from the larger dimension at the end remote from section 28 to the narrower end where it is connected to the section 28, and in order to compensate for this reduction in shaft diameter, the flights 23 and 34 are made of increasing height from the larger end to the smaller end of the shaft section 24 and 26 as the case may be, in order that the tops of the flights will sweep through the same cylindrical plane. This reducing of the shaft diameter also provides an additional means of ensuring that the muck will continue to be fed by the auger sections to the section 28 even although the muck may be the box muck referred to herein.

In the embodiment of the invention shown in Figure 6, the auger layout is for use with a spreading machine of the type set forth wherein the opening is at one end of the hopper and there is a main section 60 and a section 62 with the paddles 40. The main section shaft 66 is of tapering cross-section as shown with flights 68 of progressively increasing height from the larger shaft end to the smaller shaft end so that the tips will travel in the same cylindrical plane 70. The section 62 has a group of paddles 40 which are similar in construction and layout to paddles 40 of the Figure 3 arrangement, the auger shown in Figure 6 however is for use in connection with a hopper which has the discharge outlet 30 at one end.

It will be noted that the paddles 40 shown in Figures 1 to 6 are rigid struts connected to the centre section 28 in the case of the rotary assembly of Figures 2 and 3, and to the end section 62 in the case of the rotary assembly as shown in Figure 6. Each of these struts has on its extremity a material displacing plate 40A, and these plates are arranged so as to be angled in two directions, the angling in a first direction serving to displace the material through the opening 52, and the angling in the other direction being to assist the displacement of the material lengthwise of the rotary assembly.Some of the plates 40A are angled to displace the material to the left for example when viewed in Figure 3, whilst others are arranged to displace the material to the right in Figure 3 so that when the material arrives at the section 28, it is not only forced into the impeller opening, but is also displaced back and forth. This is desirable to prevent large stones or the like from jamming in the paddles.

The paddles as shown in Figs. 1 to 6 are rigid in nature, but in accordance with the present invention, as explained with reference to Figures 7, 8 and 9, the paddles 40 are replaced by paddles 70 as shown in Figures 7, 8 and 9.

Referring to these figures, in Figure 7, the hexagonal central section 28 of the rotary assembly shaft is shown, and one of the paddles 70 is shown in cross-sectional elevation.

It should be mentioned that the section 28 has a plurality of paddles 70 respectively mounted similarly to the paddles for example as shown in Figure 3 or Figure 6, and the paddles have material deflecting plates 70A which are angularly disposed similarly to the plates 40A in that they are angled to the direction of rotation 72, and are also angled so as to displace material axially of the rotary assembly as described above. In this connection some of the plates 70A are angled to displace the material axially of the rotary assembly in one direction, whilst others of the plates 70A are angled to displace the material in the opposite direction.

As shown in Figure 7, each paddle comprises an elongated strut 73 which is welded by means of a pair of plates 74A as shown in Fig. 8 to one of the hexagonal faces of the shaft 28 so that the strut 72 in fact projects forwardly relative to the core 28 having regard to the direction of rotation of the rotary assembly 72. The strut 73 comprises an outer sleeve 74 in which is slidably contained an inner sleeve 76. The inner sleeve 76 has a covering of plastic 78 which forms a bearing to enable the smooth sliding of the inner sleeve 76 in the outer sleeve 74, and also to protect the sleeve 76 from the aggressive nature of the material being handled.

Inside the sleeve 76 at the inner end thereof is a nut 80 in which is threaded an adjustment bolt 82. The bolt 82 passes through an end plate 84 of the outer sleeve 74, and the nut head 86 rests on the outer surface of the end plate 84. A compression spring 88 acts between the end plate 84 and the nut 80 urging the sleeve 76 to an outward position which is limited by the seating of the nut head 86 on the end plate 84.

The plate 70A is secured to the other and outer end of sleeve 76. Plate 70A has a curved outer edge 90 which sweeps in a pitch circle 92. The positioning of the edge 90 can be varied by adjustment of the screw 86 so as to pull the sleeve 76 further into sleeve 84 as required.

Plate 70A has an inner edge 92 which slidably engages a guide plate 94 mounted on a V-shaped guide 96. Plate 94 and plate 96 are better illustrated in Fig. 9. The assembly comprising plates 94 and 96 is welded to the adjacent hexagonal flat on the shaft 28 in advance of the flat to which the strut is welded having regard to the direction of rotation 72 of the rotary assembly.

The plate 94 serves to engage the edge 92 of plate 70A and therefore prevents the sleeve 76 and the plate 70A from spinning about the axis of the strut when the apparatus is in use. The sleeves may in another arrangement be of square or other non-circular section so that the plate 94 may be omitted and the covering 78 of plastic material may also be omitted.

The apex of the V-plate 96 faces the direction of rotation and so will smoothly disperse and spread material to opposite sides of the strut thereby to protect same from impacts and abrasion.

The opening from the hopper 52 is also shown in Fig. 7 as is door 54. The dotted line extension of the door 54, indicated by reference 98 is in fact a rubber sealing strip or the like.

In the operation of the apparatus, the plates 70A of the paddles will engage and push the material through the opening 52 so that it can be engaged by the impeller 42 as described herein, but it is to be noted that in use if the plate 70A meets an obstruction, or a hard caked portion of material, it can retract into the sleeve 74 against the action of the spring 88, thereby protecting the struts from overloading.

It is believed furthermore that as the rotor rotates, each paddle 70 will effect a pumping action to assist in pumping material through the opening 52. As each paddle rotates, it will as it moves downwardly towards the bottom of the hopper commence engagement with and to compress straw manure material (the box muck referred to herein). This tough manure has to be sheared and torn away from the remainder of the material as it is forced downwards between the auger core and the side of the hopper body. It is believed that the spring 88 will compress as a result of displacement of the sleeve 76 and its plate 70A, to a considerable extent, which will depend upon the strengh of the spring. When the paddle reaches a position approximately as shown in Figure 7, the plate may have been deflected rearwardly for example to the position shown in dotted lines, and the spring may start to re-expand, pushing the paddle towards the door opening 52, and thereby achieving a pumping action on the material.

Other constructions involving two-part paddles with spring loading therebetween can be adopted for achieving the same type of operation.

Claims (7)

1. A spreading machine of the type set forth wherein the auger has at least one paddle for moving material towards and through the opening in one of the side walls, and said paddle comprises relatively movable portions which are urged by spring means to maintain an operative condition, but which under load can be moved relatively in order for example to override an obstruction.

2. A spreading machine according to Claim 1, wherein the auger has a plurality of said paddles.

3. A spreading machine according to Claim 1 or Claim 2, wherein the or each paddle is in the form of an elongated strut with the said parts being arranged to interfit telescopically, and said spring means comprising a compression spring arranged between the parts.

4. A spreading machine according to Claim 3, wherein the end of the paddle has an operational face for engaging the material, said face being connected to one of said telescopically interfitting parts.

5. A spreading machine according to Claim 3 or 4, wherein one part of said telescopically interfitting parts is rigidly secured to the rotor core of the rotary assembly, and the other part carries said working plate or face and is telescopically interfitted in the said first mentioned part.

6. A spreading machine according to Claim 3, 4 or 5, wherein adjacent the or each paddle, there is provided a shield structure in the form of a V-shaped plate which protects the telescoping part of the associated paddle, and a guide plate which forms a shielding and guide means for the end plate of the paddle to prevent it from rotating about the axis of the strut.

7. A spreading machine of the type set forth substantially as hereinbefore described with reference to the accompanying drawings.